A novel phosphoprotein separation material was developed, which is constructed by a magnetic mesoporous Fe3 O4@TiO2（Fe3 O4@mTiO2） microsphere and a 5-aminoisophthalic acid（AIPA） monolayer that provides additional ...A novel phosphoprotein separation material was developed, which is constructed by a magnetic mesoporous Fe3 O4@TiO2（Fe3 O4@mTiO2） microsphere and a 5-aminoisophthalic acid（AIPA） monolayer that provides additional binding sites toward phosphate groups. The results of characteristic experiments demonstrated that Fe3 O4@mTiO2-AIPA had good dispersability, high magnetic susceptibility, and satisfactory grafting ratio of AIPA, ascribed to the large specific surface area of the inorganic substrate. Taking advantages of these features, Fe3 O4@mTiO2-AIPA was successfully utilized to separate α-casein（a typical phosphoprotein） and bovine serum albumin（BSA, a typical non-phosphoprotein） from their mixtures（molar ratio = 1:2）. Through adjusting pH and polarity of solutions, the BSA and α-casein were respectively enriched in washing fraction and elution fraction. This result displays the good potential of Fe3 O4@mTiO2-AIPA for application in phosphoprotein enrichment.展开更多
BACKGROUND Ovarian cancer(OC)is the most lethal gynecological cancer among females,and its early diagnosis could help for better outcomes of the patients.AIM To investigate the utility of serum insulin-like growth fac...BACKGROUND Ovarian cancer(OC)is the most lethal gynecological cancer among females,and its early diagnosis could help for better outcomes of the patients.AIM To investigate the utility of serum insulin-like growth factors-binding proteins 2(IGFBP2),secreted phosphoprotein 1(SPP1),thrombospondin 1 protein(TSP1)and D-dimer levels in addition to currently used biomarkers[cancer antigen 125(CA125)and human epididymis protein 4(HE4)]in the diagnosis of epithelial OC(EOC).METHODS This is a case-control study that included fifty females diagnosed with EOC,10 females with benign ovarian masses recruited from the Egyptian National Cancer Institute,and 30 healthy females as a control group.All subjects were assessed for serum HE4,CA125,IGFBP2,TSP1 and SPP1 measurement by enzyme-linkedimmunosorbent assay.RESULTS There was a statistically significant difference in serum levels between EOC,benign ovarian masses,and healthy control groups regarding CA125 and SPP1(P<0.001 for both markers),while HE4 and IGFBP2 increased significantly in EOC compared to healthy control groups(P<0.001 for all markers)with no significant difference between EOC and benign ovarian masses groups.However,there was no statistically significant difference among EOC,benign ovarian masses,and healthy control groups regarding the TSP1 serum levels(P=0.051).Receiver operating characteristic analysis revealed that combined assessment of SPP1 with CA125 or TSP1 increased the diagnosis of EOC patients to a sensitivity,specificity,and area under curve of(93.3%,100%,0.968;respectively,P<0.001).CONCLUSION SPP1 may be a potential marker for the differentiation between benign and malignant ovarian masses,while IGFBP2 can differentiate between healthy females and females with ovarian masses.Combining SPP1 with CA125 or TSP1 provides high sensitivity and specificity for the detection of EOC patients.展开更多
BACKGROUND Perianal fistulae are either primary(idiopathic)or secondary[commonly associated with Crohn’s disease,(CD)].It is assumed,although not proven,that the pathophysiology differs.AIM To systematically compare ...BACKGROUND Perianal fistulae are either primary(idiopathic)or secondary[commonly associated with Crohn’s disease,(CD)].It is assumed,although not proven,that the pathophysiology differs.AIM To systematically compare the clinical phenotypes,cytokine and phosphoprotein profiles of idiopathic and CD-related perianal fistulae.METHODS Sixty-one patients undergoing surgery for perianal fistula were prospectively recruited(48 idiopathic,13 CD)into a cohort study.Clinical data,including the Perineal Disease Activity Index(PDAI)and EQ-5D-5L were collected.Biopsies of the fistula tract,granulation tissue,internal opening mucosa and rectal mucosa were obtained at surgery.Concentrations of 30 cytokines and 39 phosphoproteins were measured in each biopsy using a magnetic bead multiplexing instrument and a chemiluminescent antibody array respectively.Over 12000 clinical and 23500 laboratory measurements were made.RESULTS The PDAI was significantly higher(indicating more active disease)in the CD group with a mean difference of 2.40(95%CI:0.52-4.28,P=0.01).Complex pathoanatomy was more prevalent in the CD group,namely more multiple fistulae,supralevator extensions,collections and rectal thickening.The IL-12p70 concentration at the internal opening specimen site was significantly higher(median difference 19.7 pg/mL,99%CI:0.2-40.4,P=0.008)and the IL-1RA/IL-1βratio was significantly lower in the CD group at the internal opening specimen site(median difference 15.0,99%CI=0.4-50.5,P=0.008).However in the remaining 27 cytokines and all 39 of the phosphoproteins across the four biopsy sites,no significant differences were found between the groups.CONCLUSION CD-related perianal fistulae are more clinically severe and anatomically complex than idiopathic perianal fistulae.However,overall there are no major differences in cytokine and phosphoprotein profiles.展开更多
Summary： The relationship between tyrosine phosphorylation （TP） and protein expression of insulin receptor （InsR） and insulin resistance （IR） in patients with gestational diabetes mellitus （GDM） was investiga...Summary： The relationship between tyrosine phosphorylation （TP） and protein expression of insulin receptor （InsR） and insulin resistance （IR） in patients with gestational diabetes mellitus （GDM） was investigated. The InsR expression and TP in skeleton muscle tissue were determined by Western blotting and immunoprecipitation in women with GDM （GDM group, n=22）, normal pregnant women （normal pregnancy group, n=22） and normal non-pregnant women （normal non-pregnant group, n=13）. Fasting plasma glucose （FPG） and fasting insulin （FINS） were measured by oxidase assay and immunoradioassay. The results showed that the levels of FPG （5.61±0.78 mmol/L）, FINS （15.42±5.13 mU/L） and Ho- meostasis model assessment-IR （HOMA-IR） （1.21±0.52） in GDM group were significantly higher than those in normal pregnancy group （4.43±0.46 mmol/L, 10.56±3.07 mU/L and 0.80±0.31 respectively） （P〈0.01）. The levels of FINS and HOMA-IR in normal pregnancy group were significantly higher than those in normal non-pregnant group （7.56±2.31 mU/L and 0.47±0.26 respectively） （P〈0.01）. There was no significant difference in the InsR expression level among the three groups （P〉0.05）. TP of InsR with insulin stimulation was significantly decreased in GDM group （0.20±0.05） as compared with normal pregnancy group （0.26±0.06） （P〈0.01）. TP of InsR with insulin stimulation in normal pregnancy group was lower than that in normal non-pregnant group （0.31±0.06） （P〈0.01）. TP of InsR with insulin stimu- lation was negatively related with HOMA-IR in GDM group （r=-0.525, P〈0.01）. There was no correlation between the protein expression of InsR and HOMA-IR in GDM group （r=-0.236, P〉0.05）. It was suggested that there is no significant correlation between the protein expression of InsR in skeletal muscle and IR in GDM, but changes in TP of InsR are associated with IR in GDM.展开更多
Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. Contrary to normal cells, proteins of this group are preferentially phosphorylated. Phosphoproteins of hepat...Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. Contrary to normal cells, proteins of this group are preferentially phosphorylated. Phosphoproteins of hepatoma nuclear matrix are selectively subjected to rapid proteolysis. By alkali treatment and a monoclonal antibody against phosphotyrosyl residue the presence of two high molecular weight bands of phosphotyrosyl-containing proteins was detected in nuclear matrices of tumor but not of normal liver cells. High molecular weight protein group of tumor nuclear matrices revealed also a rapid turnover and preferential incorporation of labeled amino acids selectively inhibited by chloramphenicol.展开更多
Objective To study the changes of prodynorphin （PDyn） gene expression and dopamine and cAMPregulated phosphoprotein of 32 kDa （DARPP-32） phosphorylation in rats with levodopa-induced dyskinesias （LID）, and to ex...Objective To study the changes of prodynorphin （PDyn） gene expression and dopamine and cAMPregulated phosphoprotein of 32 kDa （DARPP-32） phosphorylation in rats with levodopa-induced dyskinesias （LID）, and to explore the mechanism of over-activation in direct pathway mediated by dopamine D1 receptor. Methods Parkinson＇s disease （PD） rats were received levodopa （10 mg/kg, i.p.） for 28 d to get the LID rats. According to the behavior scale, LID rats were divided into mild （n=8） and severe （n=16） groups. On day 29, 8 rats in severe LID group were given an acute intraperitoneal injection of MK-801 （0.1 mg/kg） 15 min before levodopa treatment （MK-801 group, n=8）. The normal rats received same course and dosage of levodopa as the control group （n=8）. Hybridization in situ was used to measure the expression of PDyn mRNA in striatum. Protein and mRNA levels of total DARPP-32 and phospho-Thr-34 DARPP-32 level were measured by immunoblotting and RT-PCR, respectively. Results The levels of PDyn mRNA and phospho-Thr-34 DARPP-32 increased significantly in LID rats compared with control rats （P〈0.01）, and they also increased markedly in severe LID group compared with mild group （P〈0.01）. Conclusion Phospho-Thr-34 DARPP-32 level was increased in LID rats, which contributed to the over-activation of direct pathway mediated by dopamine D1 receptor.展开更多
AIM： To elucidate the localization of vasodilator stimulated phosphoprotein （VASP）, a cytoskeletal organizing protein and a substrate of protein kinases A and G in mitotic gastric cancer cells. METHODS： Immunofluo...AIM： To elucidate the localization of vasodilator stimulated phosphoprotein （VASP）, a cytoskeletal organizing protein and a substrate of protein kinases A and G in mitotic gastric cancer cells. METHODS： Immunofluorescence microscopy was used to observe the localization of α-tubulin, VASP and Ser157 phosphorylated VASP （p-VASP） in interphase of mitotic gastric cancer of the cell line SGC-7901. RESULTS： Immunofluorescence staining showed that p-VASP but not VASP was co-localized with α-tubulin on spindle poles and fibers in prophase, metaphase and anaphase of the mitotic process of the gastric cancer cell line SGC-7901. H89, an inhibitor of protein kinases A and G, had no effect on the localization of p-VASP on the spindles. CONCLUSION： VASP may play a role in assembling and stabilizing the mitotic spindle of cells, and phosphorylation of the protein is the precondition for it to exert this function.展开更多
Although many tumor markers have been identified and studied in epithelial ovarian cancer,a potential and useful screening marker for ovarian cancer has not been yet clearly established. Ovarian cancer is considered a...Although many tumor markers have been identified and studied in epithelial ovarian cancer,a potential and useful screening marker for ovarian cancer has not been yet clearly established. Ovarian cancer is considered as a "silent killer"because of the absence of specific symptoms until late stage. Several validated biomarkers are currently used to diagnose and monitor the progression of the cancer,but very few of them show adequate specificity and sensitivity for different population screening. There is therefore an urge need to find biomarkers with high diagnostic accuracy and set up screening programs which can help detect ovarian cancer early,predict the response of the patient to anticancer therapy and guide physicians in choosing the best treatment for the patient. CA125,HE4 and STIP1 have been proven to play an important role as biomarkers in detecting and monitoring ovarian cancer. In this paper,we review evaluate,and highlight the role of CA125,HE4 and STIP1 in the detection of ovarian cancer.Potential biomarkers can help us distinguish malignancy from benign pelvic mass.展开更多
A sensitive method based on the fluorescence quenching effect of the Tb^3＋-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus （ALP） released from fish plasma. The detection l...A sensitive method based on the fluorescence quenching effect of the Tb^3＋-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus （ALP） released from fish plasma. The detection limit was 5.4 ng/ml （S/N=2）, and the relative standard deviation of the quenching effect （6 replicates） was 4.6%. The results obtained by the proposed method were in good agreement with those obtained by the colorimetric assay. The advantages of the present method are its relatively simple detection procedure, the lack of toxic organic solvents, and high sensitivity.展开更多
Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-...Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L).P connects nucleocapsid protein(N)with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins,and many viral proteins are also themselves sumoylated.In this study,we found that the P of HPIV3 could be sumoylated,and mutation of K492 and K532 to arginine(PK492 R/K532 R)failed to be sumoylated within P,which enhances HPIV3 minigenome activity.Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N,formation of homo-tetramers and formation of inclusion bodies.Finally,we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R)increased viral production in culture cells,suggesting that sumoylation attenuates functions of P and down-regulates viral replication.展开更多
人核仁磷酸化蛋白1(Nucleolar and coiledbody phosphoprotein 1,NOLC1)在癌症的发生发展过程中起着至关重要的调控作用,为探讨NOLC1对肺癌细胞的作用,本研究通过Gateway系统构建重组NOLC1腺病毒载体,成功包装NOLC1腺病毒后,分别感染正...人核仁磷酸化蛋白1(Nucleolar and coiledbody phosphoprotein 1,NOLC1)在癌症的发生发展过程中起着至关重要的调控作用,为探讨NOLC1对肺癌细胞的作用,本研究通过Gateway系统构建重组NOLC1腺病毒载体,成功包装NOLC1腺病毒后,分别感染正常人类胚胎肺细胞(HEL)和非小细胞肺癌细胞(A549细胞),过表达NOLC1。通过MTT实验、AnnexinV-APC/PI双染法和线粒体膜电位实验,证明与HEL细胞相比,NOLC1的过表达对A549细胞的活性降低、凋亡增加、线粒体膜电位下降影响较为显著;通过Real-time PCR检测Caspase家族、TNF与受体家族和BCL2家族基因的表达,发现过表达NOLC1明显上调了A549细胞中促凋亡基因的表达,下调了抗凋亡基因的表达,其中两种重要的促凋亡蛋白CASP8和BAX均显著上调,但是在HEL细胞中这种影响不明显。研究结果表明过表达NOLC1蛋白通过对线粒体通路和死亡受体通路的共同作用,对非小细胞癌具有显著的抗肿瘤活性。展开更多
Objective:To investigate the potential role of human cytomegalovirus lower matrix phosphoprotein 65(HCMV-pp65) in murine systemic lupus erythematosus(SLE).Methods:The prokaryotic plasmid pET-28b-pp65 was constructed t...Objective:To investigate the potential role of human cytomegalovirus lower matrix phosphoprotein 65(HCMV-pp65) in murine systemic lupus erythematosus(SLE).Methods:The prokaryotic plasmid pET-28b-pp65 was constructed to express the HCMVpp65 protein.BXSB mice and C57BL/6 mice were inoculated with pp65 eukarvotic plasmid pcDNA3.0-pp65 intramuscularly 5 times at 2-week intervals,and then the blood of the mice was subsequently collected via the retro-orbital vein.Indirect ELISAs were used to evaluate the concentration of anti-pp65 immunoglobulin G,anti-double-stranded DNA and antinuclear antibodies.lnterleukin-1β and tumor necrosis factor-α were also determined by competitive ELISA.At the same time,3 major SLE-related circulating microRNAs were examined by quantitative RT-PCR.Results:The early production of autoantibodies was observed in pp65-immunized male BXSB as well as C57BL/6 mice.Overexpression of interleukin-1β and tumor necrosis factor-a were detected in pp65-immunized male BXSB mice.Quantitative RT-PCR analyses showed that three SLE related microRNAs(microRNA-126,microRNA-125 a,and microRKA-146a) were dovvnrcgulatcd in peripheral blood mononuclear cells of pp65-immunizcd mice.Conclusions:Our findings indicate that HCMV-pp65 immunization strongly triggers the development and progression of" SLE-like disease in both BXSB and C57BL/6 mice,which indicates that the immune responses induced by HCMV-pp65 may be involved in the development of SLE.展开更多
OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in s...OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in stria⁃tal neurotransmission that affect glutamatergic transmission to control the etiology of neuropsy⁃chiatric disorders.METHODS To study dorsal striatum(DS)region-specific neuronal and behav⁃ioral responses modulated by M4 receptors,we used clustered regularly interspaced short palin⁃dromic repeats-associated protein 9 technology to generate mice lacking M4 in the dorsal stria⁃tum(DS-M4-KD).The M4 positive allosteric modu⁃lator,VU0467154,were used to study the phar⁃macologically profiles with M4 receptor stimula⁃tion in WT mice.Oxotremorine M(Oxo-M),a no subtype-selective muscarinic agonist,was used to show that mAchRs activation,in order to dissect the particular function of M4,in DS-M4-KD mice.Open filed test and forced swim test were used to assess the change of psychiatric-like behav⁃iors.Western blotting and immunohistochemistry were used to detect protein levels of phosphory⁃lation site of dopamine-and cAMP-regulated phosphoprotein of 32 ku(DARPP-32).Whole-cell patch-clamp recording was used to assess M4-mediated cholinergic inhibition of glutamater⁃gic synaptic input transmission.RESULTS West⁃ern blotting and immunohistochemistry assay showed VU0467154(5 mg·kg-1,ip)promoted phosphorylation of DARPP-32 at Thr75,and atten⁃uated D1-dependent phosphorylation of DARPP-32 at Thr34 within the mouse DS.Consistently,the Oxo-M(4μg,icv)also increased DARPP-32 phosphorylation at site Thr75 to reversed phos⁃phorylation at site Thr34 in WT mice,but not in DS-M4-KD mice.In parallel with altered DARPP-32 responses,VU0467154 or Oxo-M evoked a psychological stress response and reversed D1-induced hyperlocomotion in mice in open field test and force swim tests.However,Oxo-M sup⁃pression of D1-depengdeng behavioral respons⁃es was impaired in DS-M4-KD mice.Whole-cell patch recording showed that VU0467154 or Oxo-M mediated endogenous cholinergic inhibition of miniature excitatory postsynaptic currents through M4 receptors,which in turn suppressed D1-depen⁃dent glutamatergic synaptic transmission in the DS.CONCLUSION This study provides evidence for the role of M4 receptors in regulation of dopa⁃mine/DARPP-32 signaling and glutamate respons⁃es in the DS,and therefore modulation of psychi⁃atric behaviors associated with D1 signaling.This results indicate the mechanisms of treatments targeting M4 in psychiatric disorders.展开更多
Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosph...Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosphoprotein(t-DARPP)has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression.To evaluate the t-DARPP expression in BC,paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+BC tumor tissues.We established 2 patient-derived xenografts(PDX)mice models to test the efficacy of trastuzumab,named model 1(non-responder)and model 2(responder).t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays.Instead,there is no response from the responder.Furthermore,mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins,enhance p95-HER2 expression and promote cell migration.We found that quercetin effectively reduced t-DARPP expression in HER2+BC cells.In t-DARPP ShRNA-suppressed cells,quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest.In conclusion,the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+BC patients has the potential as a biomarker for mitigating drug resistance.展开更多
To better understand the mechanism of sugar signaling in rice cell, the suspension-cultured rice cells were transferred from sucrose-containing (+S) to sucrose-free (-S) of MS culture medium, we found that ribosomal R...To better understand the mechanism of sugar signaling in rice cell, the suspension-cultured rice cells were transferred from sucrose-containing (+S) to sucrose-free (-S) of MS culture medium, we found that ribosomal RNAs (rRNAs) were degraded progressively. This suggests that carbon, nitrogen, and phosphate were recycled in this process and the reduction in cellular rRNAs might lead to decreased translation to save energy in response to sugar starvation. Differential screening revealed that two groups of genes, sugar-starvation-repressed (SSR) and sugar-starvation-activated (SSA) genes, were regulated by sugar in an opposing manner. Northern-blot analysis showed that two major hybridization signals of 0.8 and 1.9 kb were induced strongly under sugar starvation. The two populations of genes corresponded with homologs of α-amylases (1.9 kb) and the glycine-rich proteins (GRPs) gene family (0.8 kb), and all were SSA genes. Expression of GRP genes was strongly induced in sugar-starved cells, which suggests that GRPs may help to protect cells against nutritional stress. Treatment of +S and -S cells with the protein kinase (PK) inhibitor staurosporine (St) and the serine/theronine phosphoprotein phosphatases 1 (PP1) and 2A (PP2A) inhibitor okadaic acid (OA) revealed that PP1 and PP2A (PPs) might be involved in increasing SSR gene expression in +S cells, and that activation of the majority of the SSA genes in -S cells might be due to PKs activity. These results suggested that PKs and PPs might be involved in the sugar regulation of SSR and SSA gene expression. An in-gel PK activity assay demonstrated that the activity of two classes of PKs (50 and 66 kDa) may be induced rapidly after transfer of +S cells to -S medium. Following transfer of -S cells to +S medium, a novel class of 38 kDa PK was induced rapidly and showed high activity. The 38 kDa PK might play a role in sugar sensing, and the 50 and 66 kDa PKs might play roles in signal sensing under sugar starvation in rice cells. These results provide valuable information on three classes of protein kinases that might play key roles in sugar sensing and signaling in rice.展开更多
BACKGROUND Dopamine and cyclic adenosine monophosphate(cAMP)-regulated phosphop-rotein with an apparent Mr of 32000(DARPP-32)is a protein that is involved in regulating dopamine and cAMP signaling pathways in the brai...BACKGROUND Dopamine and cyclic adenosine monophosphate(cAMP)-regulated phosphop-rotein with an apparent Mr of 32000(DARPP-32)is a protein that is involved in regulating dopamine and cAMP signaling pathways in the brain.However,recent studies have shown that DARPP-32 is also expressed in other tissues,including colorectal cancer(CRC),where its function is not well understood.AIM To explore the effect of DARPP-32 on CRC progression.METHODS The expression levels of DARPP-32 were assessed in CRC tissues using both quantitative polymerase chain reaction and immunohistochemistry assays.The proliferative capacity of CRC cell lines was evaluated with Cell Counting Kit-8 and 5-ethynyl-2’-deoxyuridine assays,while apoptosis was measured by flow cytometry.The migratory and invasive potential of CRC cell lines were deter-mined using wound healing and transwell chamber assays.In vivo studies involved monitoring the growth rate of xenograft tumors.Finally,the underlying molecular mechanism of DARPP-32 was investigated through RNA-sequencing and western blot analyses.RESULTS DARPP-32 was frequently upregulated in CRC and associated with abnormal clinicopathological features in CRC.Overexpression of DARPP-32 was shown to promote cancer cell proliferation,migration,and invasion and reduce apoptosis.DARPP-32 knockdown resulted in the opposite functional effects.Mechanistically,DARPP-32 may regulate the phosphoinositide 3-kinase(PI3K)/AKT signaling pathway in order to carry out its biological function.CONCLUSION DARPP-32 promotes CRC progression via the PI3K/AKT signaling pathway.展开更多
Prostate cancer is a major public health concern world-wide, being one of the most prevalent cancers in men. Great improvements have been made both in terms of early diagnosis and therapeutics. However, there is still...Prostate cancer is a major public health concern world-wide, being one of the most prevalent cancers in men. Great improvements have been made both in terms of early diagnosis and therapeutics. However, there is still an urgent need for reliable biomarkers that could overcome the lack of cancer-specifcity of prostate-specifc antigen, as well as alternative therapeutic targets for advanced metastatic cases. Reversible phosphorylation of proteins is a post-translational modifcation critical to the regulation of numerous cellular processes. Phosphoprotein phosphatase 1 （PPP1） is a major serine/threonine phos-phatase, whose specifcity is determined by its interacting proteins. These interactors can be PPP1 substrates, regulators, or even both. Deregulation of this protein-protein interaction network alters cell dynamics and underlies the development of several cancer hallmarks. Therefore, the identification of PPP1 interactome in specific cellular context is of crucial importance. The knowledge on PPP1 complexes in prostate cancer remains scarce, with only 4 holoenzymes characterized in human prostate cancer models. However, an increasing number of PPP1 interactors have been identifed as expressed in human prostate tissue, including the tumor suppressors TP53 and RB1. Efforts should be made in order to identify the role of such proteins in prostate carcinogenesis, since only 26 have yet well-recognized roles. Here, we revise literature and human protein databases to provide an in-depth knowledge on the biological significance of PPP1 complexes in human prostate carcinogenesis and their potential use as therapeutic targets for the development of new therapies for prostate cancer.展开更多
Reversible protein phosphorylation is a central regulatory mechanism of cell function. Deregulation of the balanced actions of protein kinases and phosphatases has been frequently associated with several pathological ...Reversible protein phosphorylation is a central regulatory mechanism of cell function. Deregulation of the balanced actions of protein kinases and phosphatases has been frequently associated with several pathological conditions, including cancer. Many studies have already addressed the role of protein kinases misregulation in cancer. However, much less is known about protein phosphatases influence. Phosphoprotein Phosphatase 1 (PPP1) is one of the major serine/threonine protein phosphatases who has three catalytic isoforms: PPP1CA, PPP1CB, and PPP1CC. Its function is achieved by binding to regulatory subunits, known as PPP1-interacting proteins (PIPs), which may prefer a catalytic isoform. Also, some inhibitors/enhancers may exhibit isoform specificity. Here we show that, prodigiosin (PG), a molecule with anticancer properties, promotes the formation of PPP1CA-AKT complex and not of PPP1CC-MAPK complex. Both, AKT and MAPK, are well-known PIPs from two pathways that crosstalk and regulate melanoma cells survival. In addition, the analysis performed using surface plasmon resonance (SPR) technology indicates that PPP1 interacts with obatoclax (OBX), a drug that belongs to the same family of PG. Overall, these results suggest that PG might, at least in part, act through PPP1C/PIPs. Also, this study is pioneer in demonstrating PPP1 isoform-specific modulation by small molecules.展开更多
OBJECTIVE: To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population. METHODS: Sample...OBJECTIVE: To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population. METHODS: Samples were obtained from 68 Chinese patients with NIDDM and 68 control subjects. The +1700-(+)4437 bp fragment of the IRS-1 gene was screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. All SSCP variations were submitted to DNA sequence analysis. RESULTS: Two amino acid variations [GGG-->AGG (G971 R) and CCT-->TCT (P1079 S)] and 3 silent mutations [GAT-->GAC(D422D), CCA-->CCC(P737 P) and GCA-->GCG (A804 A)] were identified, among which the CCA-->CCC(P737 P) and CCT-->TCT(P1079S) have not been previously reported. All five variations were found in Chinese patients with NIDDM, while GCA-->GCG(A804A) was the only one found in control subjects. The overall incidence of the five variations in Chinese patients with NIDDM were much higher than that in control subjects (38.2% vs 7.4%, chi 2 = 18.42, P GCG (A804A), and its frequency was significantly higher in Chinese patients with NIDDM than in controls (26.5% vs 7.4%, chi 2 = 8.84, P 0.05). CONCLUSION: These results indicate that there may be a relation between these nucleotide variations of IRS-1 gene and Chinese patients with NIDDM.展开更多
Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(...Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(TKIs),sorafenib and lenvatinib,and to identify a novel therapeutic target for overcoming TKI resistance in hepatocellular carcinoma(HCC).Methods:We performed a systematic integrative analysis of publicly available gene expression datasets and whole-transcriptome sequencing data from 9 pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues,respectively,to identify key molecules that might induce resistance to TKIs.We then performed in vitro and in vivo experiments to validate selected targets and related mechanisms.The associations of plasma secreted phosphoprotein 1(SPP1)expression levels before sorafenib/lenvatinib treatment with progression-free survival(PFS)and overall survival(OS)of 54 patients with advanced HCC were evaluated using Kaplan-Meier and Cox regression analysis.Results:Bioinformatic analysis identified CAF-derived SPP1 as a candidate molecule driving TKI resistance.SPP1 inhibitors reversed CAF-induced TKI resistance in vitro and in vivo.CAF-derived SPP1 activated rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)through the integrin-protein kinase C-alpha(PKCα)signaling pathway and promoted epithelial-to-mesenchymal transition(EMT).A high plasma SPP1 level before TKI treatment was identified as an independent predictor of poor PFS(P=0.026)and OS(P=0.047)in patients with advanced HCC after TKI treatment.Conclusions:CAF-derived SPP1 enhances TKI resistance in HCC via bypass activation of oncogenic signals and EMT promotion.Its inhibition represents a promising therapeutic strategy against TKI resistance inHCC.Moreover,plasma SPP1 level before TKI treatment represents a potential biomarker for treatment response prediction.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51473131,21275114,51533007 and 51521001)the Major State Basic Research Development Program of China(973 Program)(No.2013CB933002)+1 种基金Hubei Provincial Department of Education for Financial Assistance Through the “Chutian Scholar” ProgramHubei Provincial Natural Science Foundation of China(No.2014CFA039)
文摘A novel phosphoprotein separation material was developed, which is constructed by a magnetic mesoporous Fe3 O4@TiO2（Fe3 O4@mTiO2） microsphere and a 5-aminoisophthalic acid（AIPA） monolayer that provides additional binding sites toward phosphate groups. The results of characteristic experiments demonstrated that Fe3 O4@mTiO2-AIPA had good dispersability, high magnetic susceptibility, and satisfactory grafting ratio of AIPA, ascribed to the large specific surface area of the inorganic substrate. Taking advantages of these features, Fe3 O4@mTiO2-AIPA was successfully utilized to separate α-casein（a typical phosphoprotein） and bovine serum albumin（BSA, a typical non-phosphoprotein） from their mixtures（molar ratio = 1:2）. Through adjusting pH and polarity of solutions, the BSA and α-casein were respectively enriched in washing fraction and elution fraction. This result displays the good potential of Fe3 O4@mTiO2-AIPA for application in phosphoprotein enrichment.
文摘BACKGROUND Ovarian cancer(OC)is the most lethal gynecological cancer among females,and its early diagnosis could help for better outcomes of the patients.AIM To investigate the utility of serum insulin-like growth factors-binding proteins 2(IGFBP2),secreted phosphoprotein 1(SPP1),thrombospondin 1 protein(TSP1)and D-dimer levels in addition to currently used biomarkers[cancer antigen 125(CA125)and human epididymis protein 4(HE4)]in the diagnosis of epithelial OC(EOC).METHODS This is a case-control study that included fifty females diagnosed with EOC,10 females with benign ovarian masses recruited from the Egyptian National Cancer Institute,and 30 healthy females as a control group.All subjects were assessed for serum HE4,CA125,IGFBP2,TSP1 and SPP1 measurement by enzyme-linkedimmunosorbent assay.RESULTS There was a statistically significant difference in serum levels between EOC,benign ovarian masses,and healthy control groups regarding CA125 and SPP1(P<0.001 for both markers),while HE4 and IGFBP2 increased significantly in EOC compared to healthy control groups(P<0.001 for all markers)with no significant difference between EOC and benign ovarian masses groups.However,there was no statistically significant difference among EOC,benign ovarian masses,and healthy control groups regarding the TSP1 serum levels(P=0.051).Receiver operating characteristic analysis revealed that combined assessment of SPP1 with CA125 or TSP1 increased the diagnosis of EOC patients to a sensitivity,specificity,and area under curve of(93.3%,100%,0.968;respectively,P<0.001).CONCLUSION SPP1 may be a potential marker for the differentiation between benign and malignant ovarian masses,while IGFBP2 can differentiate between healthy females and females with ovarian masses.Combining SPP1 with CA125 or TSP1 provides high sensitivity and specificity for the detection of EOC patients.
基金Supported by Bowel and Cancer Research charity,No.MMBG1J3R
文摘BACKGROUND Perianal fistulae are either primary(idiopathic)or secondary[commonly associated with Crohn’s disease,(CD)].It is assumed,although not proven,that the pathophysiology differs.AIM To systematically compare the clinical phenotypes,cytokine and phosphoprotein profiles of idiopathic and CD-related perianal fistulae.METHODS Sixty-one patients undergoing surgery for perianal fistula were prospectively recruited(48 idiopathic,13 CD)into a cohort study.Clinical data,including the Perineal Disease Activity Index(PDAI)and EQ-5D-5L were collected.Biopsies of the fistula tract,granulation tissue,internal opening mucosa and rectal mucosa were obtained at surgery.Concentrations of 30 cytokines and 39 phosphoproteins were measured in each biopsy using a magnetic bead multiplexing instrument and a chemiluminescent antibody array respectively.Over 12000 clinical and 23500 laboratory measurements were made.RESULTS The PDAI was significantly higher(indicating more active disease)in the CD group with a mean difference of 2.40(95%CI:0.52-4.28,P=0.01).Complex pathoanatomy was more prevalent in the CD group,namely more multiple fistulae,supralevator extensions,collections and rectal thickening.The IL-12p70 concentration at the internal opening specimen site was significantly higher(median difference 19.7 pg/mL,99%CI:0.2-40.4,P=0.008)and the IL-1RA/IL-1βratio was significantly lower in the CD group at the internal opening specimen site(median difference 15.0,99%CI=0.4-50.5,P=0.008).However in the remaining 27 cytokines and all 39 of the phosphoproteins across the four biopsy sites,no significant differences were found between the groups.CONCLUSION CD-related perianal fistulae are more clinically severe and anatomically complex than idiopathic perianal fistulae.However,overall there are no major differences in cytokine and phosphoprotein profiles.
基金supported by the Doctoral Fund of ShandongProvince in China(No.2006BS03053)
文摘Summary： The relationship between tyrosine phosphorylation （TP） and protein expression of insulin receptor （InsR） and insulin resistance （IR） in patients with gestational diabetes mellitus （GDM） was investigated. The InsR expression and TP in skeleton muscle tissue were determined by Western blotting and immunoprecipitation in women with GDM （GDM group, n=22）, normal pregnant women （normal pregnancy group, n=22） and normal non-pregnant women （normal non-pregnant group, n=13）. Fasting plasma glucose （FPG） and fasting insulin （FINS） were measured by oxidase assay and immunoradioassay. The results showed that the levels of FPG （5.61±0.78 mmol/L）, FINS （15.42±5.13 mU/L） and Ho- meostasis model assessment-IR （HOMA-IR） （1.21±0.52） in GDM group were significantly higher than those in normal pregnancy group （4.43±0.46 mmol/L, 10.56±3.07 mU/L and 0.80±0.31 respectively） （P〈0.01）. The levels of FINS and HOMA-IR in normal pregnancy group were significantly higher than those in normal non-pregnant group （7.56±2.31 mU/L and 0.47±0.26 respectively） （P〈0.01）. There was no significant difference in the InsR expression level among the three groups （P〉0.05）. TP of InsR with insulin stimulation was significantly decreased in GDM group （0.20±0.05） as compared with normal pregnancy group （0.26±0.06） （P〈0.01）. TP of InsR with insulin stimulation in normal pregnancy group was lower than that in normal non-pregnant group （0.31±0.06） （P〈0.01）. TP of InsR with insulin stimu- lation was negatively related with HOMA-IR in GDM group （r=-0.525, P〈0.01）. There was no correlation between the protein expression of InsR and HOMA-IR in GDM group （r=-0.236, P〉0.05）. It was suggested that there is no significant correlation between the protein expression of InsR in skeletal muscle and IR in GDM, but changes in TP of InsR are associated with IR in GDM.
文摘Our previous studies showed a predominance of high molecular weight protein group in tumor nuclear matrices. Contrary to normal cells, proteins of this group are preferentially phosphorylated. Phosphoproteins of hepatoma nuclear matrix are selectively subjected to rapid proteolysis. By alkali treatment and a monoclonal antibody against phosphotyrosyl residue the presence of two high molecular weight bands of phosphotyrosyl-containing proteins was detected in nuclear matrices of tumor but not of normal liver cells. High molecular weight protein group of tumor nuclear matrices revealed also a rapid turnover and preferential incorporation of labeled amino acids selectively inhibited by chloramphenicol.
文摘Objective To study the changes of prodynorphin （PDyn） gene expression and dopamine and cAMPregulated phosphoprotein of 32 kDa （DARPP-32） phosphorylation in rats with levodopa-induced dyskinesias （LID）, and to explore the mechanism of over-activation in direct pathway mediated by dopamine D1 receptor. Methods Parkinson＇s disease （PD） rats were received levodopa （10 mg/kg, i.p.） for 28 d to get the LID rats. According to the behavior scale, LID rats were divided into mild （n=8） and severe （n=16） groups. On day 29, 8 rats in severe LID group were given an acute intraperitoneal injection of MK-801 （0.1 mg/kg） 15 min before levodopa treatment （MK-801 group, n=8）. The normal rats received same course and dosage of levodopa as the control group （n=8）. Hybridization in situ was used to measure the expression of PDyn mRNA in striatum. Protein and mRNA levels of total DARPP-32 and phospho-Thr-34 DARPP-32 level were measured by immunoblotting and RT-PCR, respectively. Results The levels of PDyn mRNA and phospho-Thr-34 DARPP-32 increased significantly in LID rats compared with control rats （P〈0.01）, and they also increased markedly in severe LID group compared with mild group （P〈0.01）. Conclusion Phospho-Thr-34 DARPP-32 level was increased in LID rats, which contributed to the over-activation of direct pathway mediated by dopamine D1 receptor.
基金Supported by National Natural Science Foundation of China, No. 30340036 and 30470891 Startup Grant from Jiangsu University, and Grant of Zhenjiang Key Institute of Clinical Laboratory Medicine (SH2006066)
文摘AIM： To elucidate the localization of vasodilator stimulated phosphoprotein （VASP）, a cytoskeletal organizing protein and a substrate of protein kinases A and G in mitotic gastric cancer cells. METHODS： Immunofluorescence microscopy was used to observe the localization of α-tubulin, VASP and Ser157 phosphorylated VASP （p-VASP） in interphase of mitotic gastric cancer of the cell line SGC-7901. RESULTS： Immunofluorescence staining showed that p-VASP but not VASP was co-localized with α-tubulin on spindle poles and fibers in prophase, metaphase and anaphase of the mitotic process of the gastric cancer cell line SGC-7901. H89, an inhibitor of protein kinases A and G, had no effect on the localization of p-VASP on the spindles. CONCLUSION： VASP may play a role in assembling and stabilizing the mitotic spindle of cells, and phosphorylation of the protein is the precondition for it to exert this function.
文摘Although many tumor markers have been identified and studied in epithelial ovarian cancer,a potential and useful screening marker for ovarian cancer has not been yet clearly established. Ovarian cancer is considered as a "silent killer"because of the absence of specific symptoms until late stage. Several validated biomarkers are currently used to diagnose and monitor the progression of the cancer,but very few of them show adequate specificity and sensitivity for different population screening. There is therefore an urge need to find biomarkers with high diagnostic accuracy and set up screening programs which can help detect ovarian cancer early,predict the response of the patient to anticancer therapy and guide physicians in choosing the best treatment for the patient. CA125,HE4 and STIP1 have been proven to play an important role as biomarkers in detecting and monitoring ovarian cancer. In this paper,we review evaluate,and highlight the role of CA125,HE4 and STIP1 in the detection of ovarian cancer.Potential biomarkers can help us distinguish malignancy from benign pelvic mass.
基金Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z424) the National Basic Research Program (973) of China (No. 2003CB415001)the Pilot Project of Knowledge Innovation Program of Chinese Academy of Sciences (No. KJCX2-SW-H06).
文摘A sensitive method based on the fluorescence quenching effect of the Tb^3＋-Tiron complex is proposed for the determination of alkali-labile phosphoprotein phosphorus （ALP） released from fish plasma. The detection limit was 5.4 ng/ml （S/N=2）, and the relative standard deviation of the quenching effect （6 replicates） was 4.6%. The results obtained by the proposed method were in good agreement with those obtained by the colorimetric assay. The advantages of the present method are its relatively simple detection procedure, the lack of toxic organic solvents, and high sensitivity.
基金supported by grants from National Key R&D Program of China(2017YFA0505801)the National Natural Science Foundation of China(81825015,81871650 and 31630086)+2 种基金National Science and Technology Major Project(2018ZX10101004)the Natural Science Foundation of Hubei Province Innovation Group(2017CFA022)Advanced Customer Cultivation Project of Wuhan National Biosafety Laboratory(2019ACCP-MS06)。
文摘Human parainfluenza virus type 3(HPIV3),a member of the Paramyxoviridae family,can cause lower respiratory disease in infants and young children.The phosphoprotein(P)of HPIV3 is an essential cofactor of the viral RNA-dependent RNA polymerase large protein(L).P connects nucleocapsid protein(N)with L to initiate genome transcription and replication.Sumoylation influences many important pathways of the target proteins,and many viral proteins are also themselves sumoylated.In this study,we found that the P of HPIV3 could be sumoylated,and mutation of K492 and K532 to arginine(PK492 R/K532 R)failed to be sumoylated within P,which enhances HPIV3 minigenome activity.Biochemical studies showed that PK492 R/K532 Rhad no effect on its interactions with N,formation of homo-tetramers and formation of inclusion bodies.Finally,we found that incorporation of K492 R/K532 R into a recombinant HPIV3(rHPIV3-PK492 R/K532 R)increased viral production in culture cells,suggesting that sumoylation attenuates functions of P and down-regulates viral replication.
基金Supported by National High Technology Research and Development Program of China(863 program No.2011AA02A116)
文摘Objective:To investigate the potential role of human cytomegalovirus lower matrix phosphoprotein 65(HCMV-pp65) in murine systemic lupus erythematosus(SLE).Methods:The prokaryotic plasmid pET-28b-pp65 was constructed to express the HCMVpp65 protein.BXSB mice and C57BL/6 mice were inoculated with pp65 eukarvotic plasmid pcDNA3.0-pp65 intramuscularly 5 times at 2-week intervals,and then the blood of the mice was subsequently collected via the retro-orbital vein.Indirect ELISAs were used to evaluate the concentration of anti-pp65 immunoglobulin G,anti-double-stranded DNA and antinuclear antibodies.lnterleukin-1β and tumor necrosis factor-α were also determined by competitive ELISA.At the same time,3 major SLE-related circulating microRNAs were examined by quantitative RT-PCR.Results:The early production of autoantibodies was observed in pp65-immunized male BXSB as well as C57BL/6 mice.Overexpression of interleukin-1β and tumor necrosis factor-a were detected in pp65-immunized male BXSB mice.Quantitative RT-PCR analyses showed that three SLE related microRNAs(microRNA-126,microRNA-125 a,and microRKA-146a) were dovvnrcgulatcd in peripheral blood mononuclear cells of pp65-immunizcd mice.Conclusions:Our findings indicate that HCMV-pp65 immunization strongly triggers the development and progression of" SLE-like disease in both BXSB and C57BL/6 mice,which indicates that the immune responses induced by HCMV-pp65 may be involved in the development of SLE.
文摘OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in stria⁃tal neurotransmission that affect glutamatergic transmission to control the etiology of neuropsy⁃chiatric disorders.METHODS To study dorsal striatum(DS)region-specific neuronal and behav⁃ioral responses modulated by M4 receptors,we used clustered regularly interspaced short palin⁃dromic repeats-associated protein 9 technology to generate mice lacking M4 in the dorsal stria⁃tum(DS-M4-KD).The M4 positive allosteric modu⁃lator,VU0467154,were used to study the phar⁃macologically profiles with M4 receptor stimula⁃tion in WT mice.Oxotremorine M(Oxo-M),a no subtype-selective muscarinic agonist,was used to show that mAchRs activation,in order to dissect the particular function of M4,in DS-M4-KD mice.Open filed test and forced swim test were used to assess the change of psychiatric-like behav⁃iors.Western blotting and immunohistochemistry were used to detect protein levels of phosphory⁃lation site of dopamine-and cAMP-regulated phosphoprotein of 32 ku(DARPP-32).Whole-cell patch-clamp recording was used to assess M4-mediated cholinergic inhibition of glutamater⁃gic synaptic input transmission.RESULTS West⁃ern blotting and immunohistochemistry assay showed VU0467154(5 mg·kg-1,ip)promoted phosphorylation of DARPP-32 at Thr75,and atten⁃uated D1-dependent phosphorylation of DARPP-32 at Thr34 within the mouse DS.Consistently,the Oxo-M(4μg,icv)also increased DARPP-32 phosphorylation at site Thr75 to reversed phos⁃phorylation at site Thr34 in WT mice,but not in DS-M4-KD mice.In parallel with altered DARPP-32 responses,VU0467154 or Oxo-M evoked a psychological stress response and reversed D1-induced hyperlocomotion in mice in open field test and force swim tests.However,Oxo-M sup⁃pression of D1-depengdeng behavioral respons⁃es was impaired in DS-M4-KD mice.Whole-cell patch recording showed that VU0467154 or Oxo-M mediated endogenous cholinergic inhibition of miniature excitatory postsynaptic currents through M4 receptors,which in turn suppressed D1-depen⁃dent glutamatergic synaptic transmission in the DS.CONCLUSION This study provides evidence for the role of M4 receptors in regulation of dopa⁃mine/DARPP-32 signaling and glutamate respons⁃es in the DS,and therefore modulation of psychi⁃atric behaviors associated with D1 signaling.This results indicate the mechanisms of treatments targeting M4 in psychiatric disorders.
基金The National Science and Technology Council of Taiwan funded this study.
文摘Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosphoprotein(t-DARPP)has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression.To evaluate the t-DARPP expression in BC,paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+BC tumor tissues.We established 2 patient-derived xenografts(PDX)mice models to test the efficacy of trastuzumab,named model 1(non-responder)and model 2(responder).t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays.Instead,there is no response from the responder.Furthermore,mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins,enhance p95-HER2 expression and promote cell migration.We found that quercetin effectively reduced t-DARPP expression in HER2+BC cells.In t-DARPP ShRNA-suppressed cells,quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest.In conclusion,the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+BC patients has the potential as a biomarker for mitigating drug resistance.
文摘To better understand the mechanism of sugar signaling in rice cell, the suspension-cultured rice cells were transferred from sucrose-containing (+S) to sucrose-free (-S) of MS culture medium, we found that ribosomal RNAs (rRNAs) were degraded progressively. This suggests that carbon, nitrogen, and phosphate were recycled in this process and the reduction in cellular rRNAs might lead to decreased translation to save energy in response to sugar starvation. Differential screening revealed that two groups of genes, sugar-starvation-repressed (SSR) and sugar-starvation-activated (SSA) genes, were regulated by sugar in an opposing manner. Northern-blot analysis showed that two major hybridization signals of 0.8 and 1.9 kb were induced strongly under sugar starvation. The two populations of genes corresponded with homologs of α-amylases (1.9 kb) and the glycine-rich proteins (GRPs) gene family (0.8 kb), and all were SSA genes. Expression of GRP genes was strongly induced in sugar-starved cells, which suggests that GRPs may help to protect cells against nutritional stress. Treatment of +S and -S cells with the protein kinase (PK) inhibitor staurosporine (St) and the serine/theronine phosphoprotein phosphatases 1 (PP1) and 2A (PP2A) inhibitor okadaic acid (OA) revealed that PP1 and PP2A (PPs) might be involved in increasing SSR gene expression in +S cells, and that activation of the majority of the SSA genes in -S cells might be due to PKs activity. These results suggested that PKs and PPs might be involved in the sugar regulation of SSR and SSA gene expression. An in-gel PK activity assay demonstrated that the activity of two classes of PKs (50 and 66 kDa) may be induced rapidly after transfer of +S cells to -S medium. Following transfer of -S cells to +S medium, a novel class of 38 kDa PK was induced rapidly and showed high activity. The 38 kDa PK might play a role in sugar sensing, and the 50 and 66 kDa PKs might play roles in signal sensing under sugar starvation in rice cells. These results provide valuable information on three classes of protein kinases that might play key roles in sugar sensing and signaling in rice.
基金Supported by Chongqing Key Diseases Research and Application Demonstration Program,No.2019ZX003General Project of Chongqing Nature Science Foundation,No.cstc2021jcyj-msxmX0283.
文摘BACKGROUND Dopamine and cyclic adenosine monophosphate(cAMP)-regulated phosphop-rotein with an apparent Mr of 32000(DARPP-32)is a protein that is involved in regulating dopamine and cAMP signaling pathways in the brain.However,recent studies have shown that DARPP-32 is also expressed in other tissues,including colorectal cancer(CRC),where its function is not well understood.AIM To explore the effect of DARPP-32 on CRC progression.METHODS The expression levels of DARPP-32 were assessed in CRC tissues using both quantitative polymerase chain reaction and immunohistochemistry assays.The proliferative capacity of CRC cell lines was evaluated with Cell Counting Kit-8 and 5-ethynyl-2’-deoxyuridine assays,while apoptosis was measured by flow cytometry.The migratory and invasive potential of CRC cell lines were deter-mined using wound healing and transwell chamber assays.In vivo studies involved monitoring the growth rate of xenograft tumors.Finally,the underlying molecular mechanism of DARPP-32 was investigated through RNA-sequencing and western blot analyses.RESULTS DARPP-32 was frequently upregulated in CRC and associated with abnormal clinicopathological features in CRC.Overexpression of DARPP-32 was shown to promote cancer cell proliferation,migration,and invasion and reduce apoptosis.DARPP-32 knockdown resulted in the opposite functional effects.Mechanistically,DARPP-32 may regulate the phosphoinositide 3-kinase(PI3K)/AKT signaling pathway in order to carry out its biological function.CONCLUSION DARPP-32 promotes CRC progression via the PI3K/AKT signaling pathway.
基金Supported by Fundao para a Ciência e Tecnologia(FCT)(PTDC/QUI-BIQ/118492/2010)Fundo Europeu de Desenvolvimento Regional(FEDER)(FCOMP-01-0124-FEDER-020895),Portugal
文摘Prostate cancer is a major public health concern world-wide, being one of the most prevalent cancers in men. Great improvements have been made both in terms of early diagnosis and therapeutics. However, there is still an urgent need for reliable biomarkers that could overcome the lack of cancer-specifcity of prostate-specifc antigen, as well as alternative therapeutic targets for advanced metastatic cases. Reversible phosphorylation of proteins is a post-translational modifcation critical to the regulation of numerous cellular processes. Phosphoprotein phosphatase 1 （PPP1） is a major serine/threonine phos-phatase, whose specifcity is determined by its interacting proteins. These interactors can be PPP1 substrates, regulators, or even both. Deregulation of this protein-protein interaction network alters cell dynamics and underlies the development of several cancer hallmarks. Therefore, the identification of PPP1 interactome in specific cellular context is of crucial importance. The knowledge on PPP1 complexes in prostate cancer remains scarce, with only 4 holoenzymes characterized in human prostate cancer models. However, an increasing number of PPP1 interactors have been identifed as expressed in human prostate tissue, including the tumor suppressors TP53 and RB1. Efforts should be made in order to identify the role of such proteins in prostate carcinogenesis, since only 26 have yet well-recognized roles. Here, we revise literature and human protein databases to provide an in-depth knowledge on the biological significance of PPP1 complexes in human prostate carcinogenesis and their potential use as therapeutic targets for the development of new therapies for prostate cancer.
基金supported by grants from Fundacao para a Ciencia e Tecnologia(FCT)of the Portuguese Ministry of Science and Higher Education(PTDC/DTP-PIC/0460/2012)by FEDER through Eixo I do Programa Operacional Fatores de Competitividade(POFC)(FCOMP-01-0124-FEDER-028692)co-funded by QREN
文摘Reversible protein phosphorylation is a central regulatory mechanism of cell function. Deregulation of the balanced actions of protein kinases and phosphatases has been frequently associated with several pathological conditions, including cancer. Many studies have already addressed the role of protein kinases misregulation in cancer. However, much less is known about protein phosphatases influence. Phosphoprotein Phosphatase 1 (PPP1) is one of the major serine/threonine protein phosphatases who has three catalytic isoforms: PPP1CA, PPP1CB, and PPP1CC. Its function is achieved by binding to regulatory subunits, known as PPP1-interacting proteins (PIPs), which may prefer a catalytic isoform. Also, some inhibitors/enhancers may exhibit isoform specificity. Here we show that, prodigiosin (PG), a molecule with anticancer properties, promotes the formation of PPP1CA-AKT complex and not of PPP1CC-MAPK complex. Both, AKT and MAPK, are well-known PIPs from two pathways that crosstalk and regulate melanoma cells survival. In addition, the analysis performed using surface plasmon resonance (SPR) technology indicates that PPP1 interacts with obatoclax (OBX), a drug that belongs to the same family of PG. Overall, these results suggest that PG might, at least in part, act through PPP1C/PIPs. Also, this study is pioneer in demonstrating PPP1 isoform-specific modulation by small molecules.
文摘OBJECTIVE: To identify the relationship between mutation in the insulin receptor substrate-1 (IRS-1) gene and the incidence of non-insulin-dependent diabetes mellitus (NIDDM) in the Chinese population. METHODS: Samples were obtained from 68 Chinese patients with NIDDM and 68 control subjects. The +1700-(+)4437 bp fragment of the IRS-1 gene was screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. All SSCP variations were submitted to DNA sequence analysis. RESULTS: Two amino acid variations [GGG-->AGG (G971 R) and CCT-->TCT (P1079 S)] and 3 silent mutations [GAT-->GAC(D422D), CCA-->CCC(P737 P) and GCA-->GCG (A804 A)] were identified, among which the CCA-->CCC(P737 P) and CCT-->TCT(P1079S) have not been previously reported. All five variations were found in Chinese patients with NIDDM, while GCA-->GCG(A804A) was the only one found in control subjects. The overall incidence of the five variations in Chinese patients with NIDDM were much higher than that in control subjects (38.2% vs 7.4%, chi 2 = 18.42, P GCG (A804A), and its frequency was significantly higher in Chinese patients with NIDDM than in controls (26.5% vs 7.4%, chi 2 = 8.84, P 0.05). CONCLUSION: These results indicate that there may be a relation between these nucleotide variations of IRS-1 gene and Chinese patients with NIDDM.
文摘Background:Cancer-associated fibroblasts(CAFs)play an important role in the induction of chemo-resistance.This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors(TKIs),sorafenib and lenvatinib,and to identify a novel therapeutic target for overcoming TKI resistance in hepatocellular carcinoma(HCC).Methods:We performed a systematic integrative analysis of publicly available gene expression datasets and whole-transcriptome sequencing data from 9 pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues,respectively,to identify key molecules that might induce resistance to TKIs.We then performed in vitro and in vivo experiments to validate selected targets and related mechanisms.The associations of plasma secreted phosphoprotein 1(SPP1)expression levels before sorafenib/lenvatinib treatment with progression-free survival(PFS)and overall survival(OS)of 54 patients with advanced HCC were evaluated using Kaplan-Meier and Cox regression analysis.Results:Bioinformatic analysis identified CAF-derived SPP1 as a candidate molecule driving TKI resistance.SPP1 inhibitors reversed CAF-induced TKI resistance in vitro and in vivo.CAF-derived SPP1 activated rapidly accelerated fibrosarcoma(RAF)/mitogen-activated protein kinase(MAPK)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)through the integrin-protein kinase C-alpha(PKCα)signaling pathway and promoted epithelial-to-mesenchymal transition(EMT).A high plasma SPP1 level before TKI treatment was identified as an independent predictor of poor PFS(P=0.026)and OS(P=0.047)in patients with advanced HCC after TKI treatment.Conclusions:CAF-derived SPP1 enhances TKI resistance in HCC via bypass activation of oncogenic signals and EMT promotion.Its inhibition represents a promising therapeutic strategy against TKI resistance inHCC.Moreover,plasma SPP1 level before TKI treatment represents a potential biomarker for treatment response prediction.
