BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in ...BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in the liver,but is depleted in some tumor tissues.However,the functional mechanisms of GAS2 in hepatocellular carcinoma(HCC)are not fully defined.AIM To investigate the function and mechanism of GAS2 in HCC.METHODS GAS2 expression in clinic liver and HCC specimens was analyzed by real-time PCR and western blotting.Cell proliferation was analyzed by counting,MTS,and colony formation assays.Cell cycle analysis was performed by flow cytometry.Cell apoptosis was investigated by Annexin V apoptosis assay and western blotting.RESULTS GAS2 protein expression was lower in HCC than in normal tissues.Overexpression of GAS2 inhibited the proliferation of HCC cells with wide-type p53,while knockdown of GAS2 promoted the proliferation of hepatocytes(P<0.05).Furthermore,GAS2 overexpression impeded the G1-to-S cell cycle transition and arrested more G1 cells,particularly the elevation of sub G1(P<0.01).Apoptosis induced by GAS2 was dependent on p53,which was increased by etoposide addition.The expression of p53 and apoptosis markers was further enhanced when GAS2 was upregulated,but became diminished upon downregulation of GAS2.In the clinic specimen,GAS2 was downregulated in more than 60%of HCCs.The average fold changes of GAS2 expression in tumor tissues were significantly lower than those in paired non-tumor tissues(P<0.05).CONCLUSION GAS2 plays a vital role in HCC cell proliferation and apoptosis,possibly by regulating the cell cycle and p53-dependent apoptosis pathway.展开更多
The impact of long terminal repeat （LTR） retrotransposition on cell fate is unknown. Here, we investigated the effect of VL30 retrotransposition on cell death in SV40-transformed mouse SVTT1 cells. Transfection of a...The impact of long terminal repeat （LTR） retrotransposition on cell fate is unknown. Here, we investigated the effect of VL30 retrotransposition on cell death in SV40-transformed mouse SVTT1 cells. Transfection of a VL30 retrotransposon decreased the clonogenicity of SVTT1 by 17-fold, as compared to parental NIH3T3 cells. Correlated levels of retrotransposition frequency and cell death rates were found in retrotransposition-positive SVTT1 cloned cells, exhibiting DNA fragmentation, nuclear condensation, multinucleation and cytoplasmic vacuolization. Analysis of activation of effector caspases revealed a caspase-independent cell death mechanism. However, cell death was associated with p53 induction and concomitant upregulation of PUMAa and Bax and downregulation of Bcl-2 and Hsp70 protein expression. Moreover, we found partial loss of colocalization of large T-antigen （LT）/p53 and p53 translocation to mitochondria, leading to mitochondrial outer membrane permeabilization （MOMP） accompanied by lysosomal membrane permeabilization （LMP）. Interestingly, treatment with the antioxidant N-acetylcysteiue abolished cell death, suggesting the involvement of mitochondrial-derived reactive oxygen species, and resulted in an increase of retrotransposition frequency. Importantly, the induction of cell death was VL30 retrotransposon-specilic as VL30 mobilization was induced; in contrast, mobilization of the non-LTR L1 （LINE-1, long interspersed nuclear element-1）, B2 and LTR MusD retrotransposons decreased. Our results provide, for the first time, strong evidence that VL30 retrotransposition mediates cell death via mitochondrial and lysosomal damage, uncovering the role of retrotransposition as a nuclear signal activating a mitochondrial-lysosomal crosstalk in triggering cell death.展开更多
The tumor suppressor protein p53 is central to cancer biology,with its pathway reactivation emerging as a promising therapeutic strategy in oncology.This study introduced LZ22,a novel compound that selectively inhibit...The tumor suppressor protein p53 is central to cancer biology,with its pathway reactivation emerging as a promising therapeutic strategy in oncology.This study introduced LZ22,a novel compound that selectively inhibits the growth,migration,and metastasis of tumor cells expressing wild-type p53,demonstrating ineffectiveness in cells devoid of p53 or those expressing mutant p53.LZ22’s mechanism of action involves a high-affinity interaction with the histidine-96 pocket of the MDM2 protein.This interaction disrupted the MDM2-p53 binding,consequently stabilizing p53 by shielding it from proteasomal degradation.LZ22 impeded cell cycle progression and diminished cell proliferation by reinstating the p53-dependent suppression of the CDK2/Rb signaling pathway.Moreover,LZ22 alleviated the p53-dependent repression of Snail transcription factor expression and its consequent EMT,effectively reducing tumor cell migration and distal metastasis.Importantly,LZ22 administration in tumor-bearing mice did not manifest notable side effects.The findings position LZ22 as a structurally unique reactivator of p53,offering therapeutic promise for the management of human cancers with wild-type TP53.展开更多
AIM： To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na （Ⅱ）. METHODS： HCT116 human colon cancer cells and Bax-...AIM： To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na （Ⅱ）. METHODS： HCT116 human colon cancer cells and Bax-null or p53-null isogenic derivatives were irradiated with a diode laser. Early apoptosis and cell death in response to photodynamic therapy were determined by MTT assays, annexin Ⅴ assays, transmission electron microscopy assays, caspase assays and western blotting. RESULTS： Induction of early apoptosis and cell death was Bax- and p53-dependent. Bax and p53 were required for caspase-dependent apoptosis. The levels of anti-apoptotic Bcl-2 family proteins, Bcl-2 and Bcl-xL, were decreased in Bax- and p53-independent manner. CONCLUSION： Our results indicate that eady apoptosis and cell death of human colon cancer cells induced by photodynamic therapy with lysosome-localizing photosensitizer ATX-S10Na （Ⅱ） are mediated by p53- Bax network and low levels of Bcl-2 and Bcl-xL proteins. Our results might help in formulating new therapeutic approaches in photodynamic therapy.展开更多
Objective To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer(CRC).Methods The miR-224-5p expression in CRC patient tissues and cell-derived exosomes was measured by laser captu...Objective To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer(CRC).Methods The miR-224-5p expression in CRC patient tissues and cell-derived exosomes was measured by laser capture microdissection and qRT-PCR,respectively.Dual-luciferase reporter gene assay was used to determine the target gene of miR-224-5p.The protein expressions of p53 and unc-51 like kinase 2(ULK2)in CRC cells were detected by western blot.Flow cytometry was used to detect cell cycle and apoptosis.Cell proliferation was measured by CCK8 and EdU assay.Results The miR-224-5p expression was upregulated in CRC tissues and increased progressively with the rise of CRC stage.CRC cells secreted extracellular miR-224-5p mainly in an exosome-dependent manner,and then miR-224-5p could be transferred to surrounding tumor cells to regulate cell proliferation in the form of autocrine or paracrine.Moreover,ULK2 was characterized as a direct target of miR-224-5p and was downregulated in CRC tissues.Interestingly,ULK2 inhibited CRC cell proliferation in a p53-dependent manner.Furthermore,exosome-derived miR-224-5p partially reversed the proliferation regulation of ULK2 on CRC cells.Conclusion Our findings demonstrate that exosome-transmitted miR-224-5p promotes p53-dependent cell proliferation by targeting ULK2 in CRC,which may offer promising targets for CRC prevention and therapy.展开更多
The mitochondrial redox state and its heterogeneity of colon cancer at tissue level have not been previously reported.Nor has how p53 regulates mitochondial respi ration been measured at(deep)tissue level,presumably d...The mitochondrial redox state and its heterogeneity of colon cancer at tissue level have not been previously reported.Nor has how p53 regulates mitochondial respi ration been measured at(deep)tissue level,presumably due to the unavailability of the technology that has sufficient spatial resolution and tissue penetration depth.Our prior work demonstrated that the mito-chondrial redox state and its intnatumor heterogeneity is associated with cancer aggressiveness in human melanoma and breast cancer in mouse models,with the more metastatic tumons exhi-bit ing localized negions of more oxidized redox state.Using the Chance redox scanner with an in-plane spatial resolution of 200 pm,we imaged the mitochondrial redox state of the wild-type p53 colon tumors(HCT116 p53 ut)and the p5-deleted colon tumors(HCT116 p53-/-)by cllcting the fuorescence si gnals of nicotinamide adenine dimucleotide(NA DH)and oxidized flavoproteins [Fp,including favin adenine dinucleotide(FAD)]from the mouse xenogmafts snap frozen at low temperature.Our results show that:(1)both tumor lines have significant degree of intratumor heterogeneity of the redox state,typically exhibiting a distinct bi modal distribution that either correlates with the spatial core-rim pattern or the“hot/oold”oxida tion-roduction patches;.(2)the p531-group is significantly more beterogencous in the mitochondrial redox state and has a more oxidized turmor core compared to the p53 wt group when the tunor sizes of the two groups are matched;(3)the tumor size dependence of the redox indices(such as Fp and Fp redox ratio)is significant in the p531-group with the larger ones being more oxidized and more hetero-geneous in their redox state,particularly more oxidized in the tumor central regions;(4)the H&E staining images of tumor soctions grossly correlate with the redox images.The present work is the first to reveal at the submillimeter scale the intratumor heterogeneity pattem of the mitochon-drial redox state in colon cancer and the first to indicate that at tissue level the mitochondial redox state is p53 dependent.The findings should assist in our understanding on colon cancer pa thology and developing new imaging biomarkers for dlinical applications.展开更多
背景:p53基因是一种关键的肿瘤抑制基因,最初因在调控细胞周期、DNA修复及凋亡中的核心作用而被广泛研究。近年来,研究发现p53在肌肉骨骼疾病中同样发挥重要作用,p53的异常表达和功能失调被认为是这些疾病发生和发展的重要因素,但具体...背景:p53基因是一种关键的肿瘤抑制基因,最初因在调控细胞周期、DNA修复及凋亡中的核心作用而被广泛研究。近年来,研究发现p53在肌肉骨骼疾病中同样发挥重要作用,p53的异常表达和功能失调被认为是这些疾病发生和发展的重要因素,但具体作用机制及临床转化潜力尚未系统阐明。目的:综述p53在肌肉骨骼疾病中的多重作用,分析p53影响疾病进展的分子机制,并评估p53作为跨疾病治疗靶点的潜力。方法:通过检索PubMed数据库2004年1月至2024年12月的文献,以“P53,Osteoporosis,Post-Menopausal Osteoporosis,Osteoarthritis,Degenerative Arthritis,Rheumatoid Arthritis,Gout,Low Back Pains,Low Back Ache,Back Pain,Scoliosis”为检索词,纳入原始研究、综述及临床试验等文献,排除非英文文献及无关机制研究,最终筛选81篇文献进行综合分析。结果与结论:p53通过调控成骨-破骨平衡(如p53-Nedd4-Runx2轴)、软骨细胞凋亡(如miR-34a-SIRT1-p53通路)、炎症递质(如肿瘤坏死因子α/白细胞介素6)及氧化应激(如p53-SLC2A9轴)等机制,参与肌肉骨骼疾病的发生发展。p53的双向作用(促凋亡与抗炎)提示需精准调控p53活性。基于基因编辑(如CRISPR/Cas9)、小分子抑制剂(如PFT-α)及天然产物(如柚皮苷)的干预策略展现出治疗潜力,但临床转化仍需进一步验证。未来需结合多学科技术深化p53机制研究与临床实践。展开更多
基金Supported by the National Natural Science Foundation of China,No.81702777Natural Science Foundation of Guangdong Province,No.2015A030310053
文摘BACKGROUND Growth arrest-specific gene 2(GAS2)plays a role in modulating in reversible growth arrest cell cycle,apoptosis,and cell survival.GAS2 protein is universally expressed in most normal tissues,particularly in the liver,but is depleted in some tumor tissues.However,the functional mechanisms of GAS2 in hepatocellular carcinoma(HCC)are not fully defined.AIM To investigate the function and mechanism of GAS2 in HCC.METHODS GAS2 expression in clinic liver and HCC specimens was analyzed by real-time PCR and western blotting.Cell proliferation was analyzed by counting,MTS,and colony formation assays.Cell cycle analysis was performed by flow cytometry.Cell apoptosis was investigated by Annexin V apoptosis assay and western blotting.RESULTS GAS2 protein expression was lower in HCC than in normal tissues.Overexpression of GAS2 inhibited the proliferation of HCC cells with wide-type p53,while knockdown of GAS2 promoted the proliferation of hepatocytes(P<0.05).Furthermore,GAS2 overexpression impeded the G1-to-S cell cycle transition and arrested more G1 cells,particularly the elevation of sub G1(P<0.01).Apoptosis induced by GAS2 was dependent on p53,which was increased by etoposide addition.The expression of p53 and apoptosis markers was further enhanced when GAS2 was upregulated,but became diminished upon downregulation of GAS2.In the clinic specimen,GAS2 was downregulated in more than 60%of HCCs.The average fold changes of GAS2 expression in tumor tissues were significantly lower than those in paired non-tumor tissues(P<0.05).CONCLUSION GAS2 plays a vital role in HCC cell proliferation and apoptosis,possibly by regulating the cell cycle and p53-dependent apoptosis pathway.
文摘The impact of long terminal repeat （LTR） retrotransposition on cell fate is unknown. Here, we investigated the effect of VL30 retrotransposition on cell death in SV40-transformed mouse SVTT1 cells. Transfection of a VL30 retrotransposon decreased the clonogenicity of SVTT1 by 17-fold, as compared to parental NIH3T3 cells. Correlated levels of retrotransposition frequency and cell death rates were found in retrotransposition-positive SVTT1 cloned cells, exhibiting DNA fragmentation, nuclear condensation, multinucleation and cytoplasmic vacuolization. Analysis of activation of effector caspases revealed a caspase-independent cell death mechanism. However, cell death was associated with p53 induction and concomitant upregulation of PUMAa and Bax and downregulation of Bcl-2 and Hsp70 protein expression. Moreover, we found partial loss of colocalization of large T-antigen （LT）/p53 and p53 translocation to mitochondria, leading to mitochondrial outer membrane permeabilization （MOMP） accompanied by lysosomal membrane permeabilization （LMP）. Interestingly, treatment with the antioxidant N-acetylcysteiue abolished cell death, suggesting the involvement of mitochondrial-derived reactive oxygen species, and resulted in an increase of retrotransposition frequency. Importantly, the induction of cell death was VL30 retrotransposon-specilic as VL30 mobilization was induced; in contrast, mobilization of the non-LTR L1 （LINE-1, long interspersed nuclear element-1）, B2 and LTR MusD retrotransposons decreased. Our results provide, for the first time, strong evidence that VL30 retrotransposition mediates cell death via mitochondrial and lysosomal damage, uncovering the role of retrotransposition as a nuclear signal activating a mitochondrial-lysosomal crosstalk in triggering cell death.
基金supported by the National Natural Science Foundation of China(Nos.82125036,82273964,81973363,82304538,81973188)the State Key Laboratory of Natural Medicines of CPU(No.SKLNMZZ202207)+3 种基金the“Double-First Class”Program of CPU,the National Key Research and Development Program of China(No.2017YFA0503900)the Jiangsu Provincial Natural Science Fund for Distinguished Young Scholar(No.BK20230042)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2023ZB171)the Shenzhen Fundamental Research Program(No.JCYJ20200109114225087).
文摘The tumor suppressor protein p53 is central to cancer biology,with its pathway reactivation emerging as a promising therapeutic strategy in oncology.This study introduced LZ22,a novel compound that selectively inhibits the growth,migration,and metastasis of tumor cells expressing wild-type p53,demonstrating ineffectiveness in cells devoid of p53 or those expressing mutant p53.LZ22’s mechanism of action involves a high-affinity interaction with the histidine-96 pocket of the MDM2 protein.This interaction disrupted the MDM2-p53 binding,consequently stabilizing p53 by shielding it from proteasomal degradation.LZ22 impeded cell cycle progression and diminished cell proliferation by reinstating the p53-dependent suppression of the CDK2/Rb signaling pathway.Moreover,LZ22 alleviated the p53-dependent repression of Snail transcription factor expression and its consequent EMT,effectively reducing tumor cell migration and distal metastasis.Importantly,LZ22 administration in tumor-bearing mice did not manifest notable side effects.The findings position LZ22 as a structurally unique reactivator of p53,offering therapeutic promise for the management of human cancers with wild-type TP53.
基金Supported by a grant from the Jikei University School of Medicine
文摘AIM： To investigate the roles of Bax and p53 proteins in photosensitivity of human colon cancer cells by using lysosome-localizing photosensitizer, ATX-S10Na （Ⅱ）. METHODS： HCT116 human colon cancer cells and Bax-null or p53-null isogenic derivatives were irradiated with a diode laser. Early apoptosis and cell death in response to photodynamic therapy were determined by MTT assays, annexin Ⅴ assays, transmission electron microscopy assays, caspase assays and western blotting. RESULTS： Induction of early apoptosis and cell death was Bax- and p53-dependent. Bax and p53 were required for caspase-dependent apoptosis. The levels of anti-apoptotic Bcl-2 family proteins, Bcl-2 and Bcl-xL, were decreased in Bax- and p53-independent manner. CONCLUSION： Our results indicate that eady apoptosis and cell death of human colon cancer cells induced by photodynamic therapy with lysosome-localizing photosensitizer ATX-S10Na （Ⅱ） are mediated by p53- Bax network and low levels of Bcl-2 and Bcl-xL proteins. Our results might help in formulating new therapeutic approaches in photodynamic therapy.
基金supported by the National Natural Science Foundation of China[Grant Number:81972803]。
文摘Objective To investigate the role and molecular mechanism of exosomal miR-224-5p in colorectal cancer(CRC).Methods The miR-224-5p expression in CRC patient tissues and cell-derived exosomes was measured by laser capture microdissection and qRT-PCR,respectively.Dual-luciferase reporter gene assay was used to determine the target gene of miR-224-5p.The protein expressions of p53 and unc-51 like kinase 2(ULK2)in CRC cells were detected by western blot.Flow cytometry was used to detect cell cycle and apoptosis.Cell proliferation was measured by CCK8 and EdU assay.Results The miR-224-5p expression was upregulated in CRC tissues and increased progressively with the rise of CRC stage.CRC cells secreted extracellular miR-224-5p mainly in an exosome-dependent manner,and then miR-224-5p could be transferred to surrounding tumor cells to regulate cell proliferation in the form of autocrine or paracrine.Moreover,ULK2 was characterized as a direct target of miR-224-5p and was downregulated in CRC tissues.Interestingly,ULK2 inhibited CRC cell proliferation in a p53-dependent manner.Furthermore,exosome-derived miR-224-5p partially reversed the proliferation regulation of ULK2 on CRC cells.Conclusion Our findings demonstrate that exosome-transmitted miR-224-5p promotes p53-dependent cell proliferation by targeting ULK2 in CRC,which may offer promising targets for CRC prevention and therapy.
基金supported by the Center of Magnetic Resonance and Optical Imaging(CMROI)-an NIH supported research resource P41 RR02305(R.Reddy)the Small Animal Imaging Resources Program 2U24-CA083105(J.D.Glickson and L.Chodosh).
文摘The mitochondrial redox state and its heterogeneity of colon cancer at tissue level have not been previously reported.Nor has how p53 regulates mitochondial respi ration been measured at(deep)tissue level,presumably due to the unavailability of the technology that has sufficient spatial resolution and tissue penetration depth.Our prior work demonstrated that the mito-chondrial redox state and its intnatumor heterogeneity is associated with cancer aggressiveness in human melanoma and breast cancer in mouse models,with the more metastatic tumons exhi-bit ing localized negions of more oxidized redox state.Using the Chance redox scanner with an in-plane spatial resolution of 200 pm,we imaged the mitochondrial redox state of the wild-type p53 colon tumors(HCT116 p53 ut)and the p5-deleted colon tumors(HCT116 p53-/-)by cllcting the fuorescence si gnals of nicotinamide adenine dimucleotide(NA DH)and oxidized flavoproteins [Fp,including favin adenine dinucleotide(FAD)]from the mouse xenogmafts snap frozen at low temperature.Our results show that:(1)both tumor lines have significant degree of intratumor heterogeneity of the redox state,typically exhibiting a distinct bi modal distribution that either correlates with the spatial core-rim pattern or the“hot/oold”oxida tion-roduction patches;.(2)the p531-group is significantly more beterogencous in the mitochondrial redox state and has a more oxidized turmor core compared to the p53 wt group when the tunor sizes of the two groups are matched;(3)the tumor size dependence of the redox indices(such as Fp and Fp redox ratio)is significant in the p531-group with the larger ones being more oxidized and more hetero-geneous in their redox state,particularly more oxidized in the tumor central regions;(4)the H&E staining images of tumor soctions grossly correlate with the redox images.The present work is the first to reveal at the submillimeter scale the intratumor heterogeneity pattem of the mitochon-drial redox state in colon cancer and the first to indicate that at tissue level the mitochondial redox state is p53 dependent.The findings should assist in our understanding on colon cancer pa thology and developing new imaging biomarkers for dlinical applications.
文摘背景:p53基因是一种关键的肿瘤抑制基因,最初因在调控细胞周期、DNA修复及凋亡中的核心作用而被广泛研究。近年来,研究发现p53在肌肉骨骼疾病中同样发挥重要作用,p53的异常表达和功能失调被认为是这些疾病发生和发展的重要因素,但具体作用机制及临床转化潜力尚未系统阐明。目的:综述p53在肌肉骨骼疾病中的多重作用,分析p53影响疾病进展的分子机制,并评估p53作为跨疾病治疗靶点的潜力。方法:通过检索PubMed数据库2004年1月至2024年12月的文献,以“P53,Osteoporosis,Post-Menopausal Osteoporosis,Osteoarthritis,Degenerative Arthritis,Rheumatoid Arthritis,Gout,Low Back Pains,Low Back Ache,Back Pain,Scoliosis”为检索词,纳入原始研究、综述及临床试验等文献,排除非英文文献及无关机制研究,最终筛选81篇文献进行综合分析。结果与结论:p53通过调控成骨-破骨平衡(如p53-Nedd4-Runx2轴)、软骨细胞凋亡(如miR-34a-SIRT1-p53通路)、炎症递质(如肿瘤坏死因子α/白细胞介素6)及氧化应激(如p53-SLC2A9轴)等机制,参与肌肉骨骼疾病的发生发展。p53的双向作用(促凋亡与抗炎)提示需精准调控p53活性。基于基因编辑(如CRISPR/Cas9)、小分子抑制剂(如PFT-α)及天然产物(如柚皮苷)的干预策略展现出治疗潜力,但临床转化仍需进一步验证。未来需结合多学科技术深化p53机制研究与临床实践。
