Salinomycin（SAL）,a polyether antibiotic isolated from Streptomyces albus,is widely used as an anticoccidial drug in poultry and other livestock and is furthermore fed to ruminescent animals to improve nutrient absor...Salinomycin（SAL）,a polyether antibiotic isolated from Streptomyces albus,is widely used as an anticoccidial drug in poultry and other livestock and is furthermore fed to ruminescent animals to improve nutrient absorption and feed efficiency.It has recently been shown to act as a specific inhibitor of cancer stem cells.At present,the price of salinomycin sodium（SAL-Na） is 10 fold lower than that of salinomycin,however,there is no report about the comparison of the inhibitory effects of SAL and SAL-Na on cancer stem cells as well as cancer cells.In the present study,side population cells（SP cells）and non-SP cells （NSP cells）sorted from human breast cancer cell line MCF-7 were chosen as the models of cancer stem cells and cancer cells, respectively.SRB assay was performed to compare the cytotoxicity of SAL and SAL-Na.First of all,SP cells were sorted from MCF-7 cells via FACSDiva flow cytometry.Secondly,the sorted SP cells were identified with the surface makers（CD44~＋/CD24^-） of breast cancer stem cells.Finally,the inhibitory effects of SAL and SAL-Na were evaluated on the sorted SP cells and NSP cells.Results showed that,as compared to breast cancer cells,the inhibitory effect of free SAL or free SAL-Na was more potent in breast cancer stem cells.Furthermore,the inhibitory effects of free SAL and free SAL-Na had no significant difference for the SP cells as well as the NSP cells when they were in the same concentration.Thus,it suggested that salinomycin sodium should be considered as a potential candidate to take the place of salinomycin in cancer stem cells research,due to their similar inhibitory effects on cancer stem cells.展开更多
Objective: To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelialmesenchymal transition(EMT), and ...Objective: To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelialmesenchymal transition(EMT), and to provide experimental basis for the treatment of urological tumors. Methods: The bladder cancer cell line T24 was cultured in vitro. The rat bladder tumor model was established in vivo. The rats were randomized into two groups, among which the rats in the experiment group were given intraperitoneal injection of salinomycin, while the rats in the control group were given intraperitoneal injection of normal saline. The change of tumor cells in the two groups was observed. Transwell was used to detect the cell migration and invasion abilities, Real-time PCR was used to detect the expression of m RNA, while Western-blot was utilized for the determination of the expressions of E-cadherin and vimentin proteins. Results: The metastasis and invasion abilities of serum bladder cancer cell line T24 after salinomycin treatment in the experiment group were significantly reduced when compared with those in the control group, and the tumor metastasis lesions were decreased from an average of 1.59 to 0.6(P<0.05). T24 cell proliferation in the experiment group was gradually decreasing. T24 cell proliferation at 48 h was significantly lower than that at 12 h and 24 h(P<0.05). T24 cell proliferation at 24 h was significantly lower than that at 12 h(P<0.05). T24 cell proliferation at each timing point in the experiment group was significantly lower than that in the control group(P<0.05). The serum m RNA level and E-cadherin expression in the tumor tissues in the experiment group were significantly higher than those in the control group, while vimentin expression level was significantly lower than that in the control group(P<0.05). Conclusions: Salinomycin can suppress the metastasis and invasion of bladder cancer cells, of which the mechanism is probably associated with the inhibition of EMT of tumor cells.展开更多
Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is...Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is not suitable for the rapid detection in daily scientific research. Besides, the assay methods of SAL-Na reported by literature are not suitable for quantification due to the interference of various excipients. Consequently, the deep study on biological mechanism of SAL-Na is hindered by its assay method. In the present study, we aimed to establish an ultraviolet visible（UV-vis） spectrophotometric method to determine the content of SAL-Na in the liposomes. The first approach was a UV spectrophotometry, in which SAL-Na was dissolved in ethanol and then detected at 287 nm. Although the standard curve measured at 287 nm by UV method had good linearity, the quantification limitation was too high to meet the requirement in determining SAL-Na in the liposomes. In addition, the membrane materials in the liposomes severely affected the measurement. The second one was an improved UV-vis spectrophotometry by vanillin derivatization. In this method, SAL-Na was dissolved in 95% ethanol, mixed with vanillin test solution and heated at 72 ℃ for 40 min for derivatization. After cooling down to room temperature, the solution was detected using UV-vis spectrophotometer at 526 nm. This method could be used to accurately determine the content of SAL-Na at lower concentration, and the absorbance value was stable for 5 d at least. Moreover, the membrane materials of the liposomes did not affect the absorbance of SAL-Na at 526 nm. The precision and recovery studies demonstrated that the vanillin derivatization approach was stable and precise in assaying SAL-Na. In conclusion, the UV-vis spectrophotometry by vanillin derivatization could be used for measuring SAL-Na in the liposomes, thereby laying a foundation for deep study of the biological mechanism of SAL-Na in the liposomes.展开更多
Objective To assess the effects of Yi Qi Jie Du Formula(YQJDF)combined with salinomycin(SAL)on nasopharyngeal carcinoma stem cells(NPC-SCs)and investigate the underlying molecular mechanisms.Methods Cell counting meth...Objective To assess the effects of Yi Qi Jie Du Formula(YQJDF)combined with salinomycin(SAL)on nasopharyngeal carcinoma stem cells(NPC-SCs)and investigate the underlying molecular mechanisms.Methods Cell counting methods,the CCK-8 assay,transwell migration assay and JC-1 staining,were used to observe the effects of the combination on the proliferation,migration and apoptosis of NPC stem cells,respectively.Western blot was used to detect the levels of protein in NPC-SCs.Results YQJDF combined with SAL had a synergistic effect on the inhibition of proliferation and migration and induction of NPCSC apoptosis.Mechanistically,YQJDF combined with SAL synergistically upregulated the levels of apoptotic proteins,including cleaved Caspase-3,cleaved Caspase-7 and cleaved Caspase-9.Moreover,YQJDF combined with SAL synergistically decreased the levels of CD44,p-c-Src,Ras,p-PKCδ,p-MEK,p-c-Raf,p-ERK1/2 and p-AKT proteins.Conclusions The combination of YQJDF and SAL has a synergistic effect on the inhibition of NPC-SC proliferation and migration and induction of apoptosis,which may be closely related to the downregulation of the CD44/Ras signaling pathway.展开更多
SalNa （sodium salinomycin） reacts with divalent transition metal ions of Co（II）, Ni（II）, Cu（II） and Zn（II） to produce novel compounds characterized by various spectroscopic methods. The interaction of metal ...SalNa （sodium salinomycin） reacts with divalent transition metal ions of Co（II）, Ni（II）, Cu（II） and Zn（II） to produce novel compounds characterized by various spectroscopic methods. The interaction of metal （II） ions with SalNa results in the formation of mononuclear complexes of a general composition of [M（Sal）2·（H2O）2] nH2O （n = 0 or 2） where the divalent cations replace Na~ ions from the cavity of initial compound. The new compounds （disalinomycinates） possess an enhanced antibacterial activity against Gram-positive microorganisms as compared to both SalNa and SalH （salinomycinic acid）, respectively. The metal （II） complexes manifest strong concentration dependent cytotoxic effect in experiments using human leukemia cell lines. The complexes of Co0I） and Cu（lI） proved to exert superior activity as compared to the Ni（II） and Zn（II） analogues and are much more cytotoxic than SalNa and SalH. Further studies should be conducted to determine the therapeutic indexes of the new compounds.展开更多
[Objective] This study aimed to explore the mutagenesis effects of N＋ ion beam implantation on Streptomyces a/bus and obtain high-yield salinomycin- producing mutant strain. [ Method ] Streptomyces a/bus strain S-11-...[Objective] This study aimed to explore the mutagenesis effects of N＋ ion beam implantation on Streptomyces a/bus and obtain high-yield salinomycin- producing mutant strain. [ Method ] Streptomyces a/bus strain S-11-04 was mutated with different doses of N ＋ implantation. The effects of low energy N ＊ implantation on the survival rate, colony morphology and salinomycin-producing ability were investigated. [ Result] The results showed that low energy N ＋ implantation can efficiently improve the positive mutation rate of Streptomyces albus; 13 mutant strains with high yield of salinomycin were isolated; to be specific, mutant strain N3- 6 has relatively good genetic stability with four continuous generations, and the titres of salinomycin were increased by 41% in the shake-flask culture and 20.5% in mass production compared with the control. [ Conclusion ] N ＋ ion beam irradiation is an effective method to obtain high-yield salinomycin-producing Streptomy- ces albus strain.展开更多
Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bac...Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bacteria are spreading at alarming rates.展开更多
A fluorescence polarization immunoassay(FPIA) for the determination of salinomycin(SAL) was developed by using anti-SAL monoclonal antibodies(mAb).Fluorescein labeled SAL(tracer) was synthesized by the N-hydroxysuccin...A fluorescence polarization immunoassay(FPIA) for the determination of salinomycin(SAL) was developed by using anti-SAL monoclonal antibodies(mAb).Fluorescein labeled SAL(tracer) was synthesized by the N-hydroxysuccinimide active ester method and purified using thin layer chromatography(TLC).The developed FPIA for SAL had a dynamic range from 0.60 to 2193 ng/mL with an IC50 value of 33.2 ng/mL and a detection limit(LOD) of 0.08 ng/mL.No significant cross-reactivities were observed with other drugs but 67.6% with narasin.展开更多
An ideal surrogate host for heterologous production of various natural products is expected to have efficient nutrient utilization,fast growth,abundant precursors and energy supply,and a pronounced gene expression.Str...An ideal surrogate host for heterologous production of various natural products is expected to have efficient nutrient utilization,fast growth,abundant precursors and energy supply,and a pronounced gene expression.Streptomyces albus BK3-25 is a high-yield industrial strain producing type-Ⅰ polyketide sahnomycin,with a unique ability of bean oil utilization.Its potential of being a surrogate host for heterologous production of PKS was engineered and evaluated herein.Firstly,introduction of a three-gene cassette for the biosynthesis of ethylmalonyl-CoA resulted in accumulation of ethylmalonyl-CoA precursor and sahnomycin,and subsequent deletion of the sahnomycin biosynthetic gene cluster resulted in a host with rich supplies of common polyketide precursors,including malonyl-CoA,methylmalonyl-CoA,and ethylmalonyl-CoA.Secondly,the energy and reducing force were measured,and the improved accumulation of ATP and NADPH was observed in the mutant.Furthermore,the strength of a series of selected endogenous promoters based on microarray data was assessed at different growth phases,and a strong constitutive promoter was identified,providing a useful tool for further engineered gene expression.Finally,the potential of the BK3-25 derived host ZXJ-6 was evaluated with the introduction of the actinorhodin biosynthetic gene cluster from Streptomyces coelicolor,and the heterologous production of actinorhodin was obtained.This work clearly indicated the potential of the high-yield sahnomycin producer as a surrogate host for heterologous production of polyketides,although more genetic manipulation should be conducted to streamline its performance.展开更多
基金National Basic Research Program of China(Grant No 2009CB930300)State Key Projects(Grant No 2009ZX093 10- 001)the 863 Project(GrantNo 2007AA021811)
文摘Salinomycin（SAL）,a polyether antibiotic isolated from Streptomyces albus,is widely used as an anticoccidial drug in poultry and other livestock and is furthermore fed to ruminescent animals to improve nutrient absorption and feed efficiency.It has recently been shown to act as a specific inhibitor of cancer stem cells.At present,the price of salinomycin sodium（SAL-Na） is 10 fold lower than that of salinomycin,however,there is no report about the comparison of the inhibitory effects of SAL and SAL-Na on cancer stem cells as well as cancer cells.In the present study,side population cells（SP cells）and non-SP cells （NSP cells）sorted from human breast cancer cell line MCF-7 were chosen as the models of cancer stem cells and cancer cells, respectively.SRB assay was performed to compare the cytotoxicity of SAL and SAL-Na.First of all,SP cells were sorted from MCF-7 cells via FACSDiva flow cytometry.Secondly,the sorted SP cells were identified with the surface makers（CD44~＋/CD24^-） of breast cancer stem cells.Finally,the inhibitory effects of SAL and SAL-Na were evaluated on the sorted SP cells and NSP cells.Results showed that,as compared to breast cancer cells,the inhibitory effect of free SAL or free SAL-Na was more potent in breast cancer stem cells.Furthermore,the inhibitory effects of free SAL and free SAL-Na had no significant difference for the SP cells as well as the NSP cells when they were in the same concentration.Thus,it suggested that salinomycin sodium should be considered as a potential candidate to take the place of salinomycin in cancer stem cells research,due to their similar inhibitory effects on cancer stem cells.
文摘Objective: To explore the effect of salinomycin on the metastasis and invasion of bladder cancer cell line T24 by regulating the related protein expression in the process of epithelialmesenchymal transition(EMT), and to provide experimental basis for the treatment of urological tumors. Methods: The bladder cancer cell line T24 was cultured in vitro. The rat bladder tumor model was established in vivo. The rats were randomized into two groups, among which the rats in the experiment group were given intraperitoneal injection of salinomycin, while the rats in the control group were given intraperitoneal injection of normal saline. The change of tumor cells in the two groups was observed. Transwell was used to detect the cell migration and invasion abilities, Real-time PCR was used to detect the expression of m RNA, while Western-blot was utilized for the determination of the expressions of E-cadherin and vimentin proteins. Results: The metastasis and invasion abilities of serum bladder cancer cell line T24 after salinomycin treatment in the experiment group were significantly reduced when compared with those in the control group, and the tumor metastasis lesions were decreased from an average of 1.59 to 0.6(P<0.05). T24 cell proliferation in the experiment group was gradually decreasing. T24 cell proliferation at 48 h was significantly lower than that at 12 h and 24 h(P<0.05). T24 cell proliferation at 24 h was significantly lower than that at 12 h(P<0.05). T24 cell proliferation at each timing point in the experiment group was significantly lower than that in the control group(P<0.05). The serum m RNA level and E-cadherin expression in the tumor tissues in the experiment group were significantly higher than those in the control group, while vimentin expression level was significantly lower than that in the control group(P<0.05). Conclusions: Salinomycin can suppress the metastasis and invasion of bladder cancer cells, of which the mechanism is probably associated with the inhibition of EMT of tumor cells.
基金National Science Foundation of China(Grant No.81673367)
文摘Salinomycin sodium（SAL-Na） is a type of antibiotic chemotherapeutic drugs with the potential to treat cancer stem cells. The assay method of SAL-Na included in the pharmacopoeia is a microbiological method, which is not suitable for the rapid detection in daily scientific research. Besides, the assay methods of SAL-Na reported by literature are not suitable for quantification due to the interference of various excipients. Consequently, the deep study on biological mechanism of SAL-Na is hindered by its assay method. In the present study, we aimed to establish an ultraviolet visible（UV-vis） spectrophotometric method to determine the content of SAL-Na in the liposomes. The first approach was a UV spectrophotometry, in which SAL-Na was dissolved in ethanol and then detected at 287 nm. Although the standard curve measured at 287 nm by UV method had good linearity, the quantification limitation was too high to meet the requirement in determining SAL-Na in the liposomes. In addition, the membrane materials in the liposomes severely affected the measurement. The second one was an improved UV-vis spectrophotometry by vanillin derivatization. In this method, SAL-Na was dissolved in 95% ethanol, mixed with vanillin test solution and heated at 72 ℃ for 40 min for derivatization. After cooling down to room temperature, the solution was detected using UV-vis spectrophotometer at 526 nm. This method could be used to accurately determine the content of SAL-Na at lower concentration, and the absorbance value was stable for 5 d at least. Moreover, the membrane materials of the liposomes did not affect the absorbance of SAL-Na at 526 nm. The precision and recovery studies demonstrated that the vanillin derivatization approach was stable and precise in assaying SAL-Na. In conclusion, the UV-vis spectrophotometry by vanillin derivatization could be used for measuring SAL-Na in the liposomes, thereby laying a foundation for deep study of the biological mechanism of SAL-Na in the liposomes.
基金We thank for the funding support from the National Natural Science Foundation of China(No.81874408,No.81973914 and No.81573721)the Natural Science Foundation of Hunan Province,China(No.2019JJ40216)Study Fundation of Hunan Provincial Education Department(No.19B439).
文摘Objective To assess the effects of Yi Qi Jie Du Formula(YQJDF)combined with salinomycin(SAL)on nasopharyngeal carcinoma stem cells(NPC-SCs)and investigate the underlying molecular mechanisms.Methods Cell counting methods,the CCK-8 assay,transwell migration assay and JC-1 staining,were used to observe the effects of the combination on the proliferation,migration and apoptosis of NPC stem cells,respectively.Western blot was used to detect the levels of protein in NPC-SCs.Results YQJDF combined with SAL had a synergistic effect on the inhibition of proliferation and migration and induction of NPCSC apoptosis.Mechanistically,YQJDF combined with SAL synergistically upregulated the levels of apoptotic proteins,including cleaved Caspase-3,cleaved Caspase-7 and cleaved Caspase-9.Moreover,YQJDF combined with SAL synergistically decreased the levels of CD44,p-c-Src,Ras,p-PKCδ,p-MEK,p-c-Raf,p-ERK1/2 and p-AKT proteins.Conclusions The combination of YQJDF and SAL has a synergistic effect on the inhibition of NPC-SC proliferation and migration and induction of apoptosis,which may be closely related to the downregulation of the CD44/Ras signaling pathway.
文摘SalNa （sodium salinomycin） reacts with divalent transition metal ions of Co（II）, Ni（II）, Cu（II） and Zn（II） to produce novel compounds characterized by various spectroscopic methods. The interaction of metal （II） ions with SalNa results in the formation of mononuclear complexes of a general composition of [M（Sal）2·（H2O）2] nH2O （n = 0 or 2） where the divalent cations replace Na~ ions from the cavity of initial compound. The new compounds （disalinomycinates） possess an enhanced antibacterial activity against Gram-positive microorganisms as compared to both SalNa and SalH （salinomycinic acid）, respectively. The metal （II） complexes manifest strong concentration dependent cytotoxic effect in experiments using human leukemia cell lines. The complexes of Co0I） and Cu（lI） proved to exert superior activity as compared to the Ni（II） and Zn（II） analogues and are much more cytotoxic than SalNa and SalH. Further studies should be conducted to determine the therapeutic indexes of the new compounds.
文摘[Objective] This study aimed to explore the mutagenesis effects of N＋ ion beam implantation on Streptomyces a/bus and obtain high-yield salinomycin- producing mutant strain. [ Method ] Streptomyces a/bus strain S-11-04 was mutated with different doses of N ＋ implantation. The effects of low energy N ＊ implantation on the survival rate, colony morphology and salinomycin-producing ability were investigated. [ Result] The results showed that low energy N ＋ implantation can efficiently improve the positive mutation rate of Streptomyces albus; 13 mutant strains with high yield of salinomycin were isolated; to be specific, mutant strain N3- 6 has relatively good genetic stability with four continuous generations, and the titres of salinomycin were increased by 41% in the shake-flask culture and 20.5% in mass production compared with the control. [ Conclusion ] N ＋ ion beam irradiation is an effective method to obtain high-yield salinomycin-producing Streptomy- ces albus strain.
基金supported by grants from the Ministry of Science and Technology of China (2015CB150600)the National Natural Science Foundation of China (31571281 and 31771378)
文摘Dear Editor,Streptomyces can produce a large variety of secondary metabolites as a major source of anti-infective, antitumor or immune-suppressive agents widely applied in clinical treatment. Antibiotics-resistant bacteria are spreading at alarming rates.
基金support from the National Natural Science Foundation of China (Grant No 30830082)the Major State Basic Research Development Program of China (Grant No 2009CB118801)Beijing Excellent Doctoral Dissertation Fund (Grant No YB20081001902)
文摘A fluorescence polarization immunoassay(FPIA) for the determination of salinomycin(SAL) was developed by using anti-SAL monoclonal antibodies(mAb).Fluorescein labeled SAL(tracer) was synthesized by the N-hydroxysuccinimide active ester method and purified using thin layer chromatography(TLC).The developed FPIA for SAL had a dynamic range from 0.60 to 2193 ng/mL with an IC50 value of 33.2 ng/mL and a detection limit(LOD) of 0.08 ng/mL.No significant cross-reactivities were observed with other drugs but 67.6% with narasin.
基金supported by grants from the National Natural Science Foundation of China(21661140002 and 31470157)the Ministry of Science and Technology of China(2012CB721005 and 2012AA022107)
文摘An ideal surrogate host for heterologous production of various natural products is expected to have efficient nutrient utilization,fast growth,abundant precursors and energy supply,and a pronounced gene expression.Streptomyces albus BK3-25 is a high-yield industrial strain producing type-Ⅰ polyketide sahnomycin,with a unique ability of bean oil utilization.Its potential of being a surrogate host for heterologous production of PKS was engineered and evaluated herein.Firstly,introduction of a three-gene cassette for the biosynthesis of ethylmalonyl-CoA resulted in accumulation of ethylmalonyl-CoA precursor and sahnomycin,and subsequent deletion of the sahnomycin biosynthetic gene cluster resulted in a host with rich supplies of common polyketide precursors,including malonyl-CoA,methylmalonyl-CoA,and ethylmalonyl-CoA.Secondly,the energy and reducing force were measured,and the improved accumulation of ATP and NADPH was observed in the mutant.Furthermore,the strength of a series of selected endogenous promoters based on microarray data was assessed at different growth phases,and a strong constitutive promoter was identified,providing a useful tool for further engineered gene expression.Finally,the potential of the BK3-25 derived host ZXJ-6 was evaluated with the introduction of the actinorhodin biosynthetic gene cluster from Streptomyces coelicolor,and the heterologous production of actinorhodin was obtained.This work clearly indicated the potential of the high-yield sahnomycin producer as a surrogate host for heterologous production of polyketides,although more genetic manipulation should be conducted to streamline its performance.
