BACKGROUND The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs,including the colon.Accordingly,studies aimed at developing therapies targeting this pathway in var...BACKGROUND The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs,including the colon.Accordingly,studies aimed at developing therapies targeting this pathway in various cancers require the identification of several factors that may play a role in regulating Notch-1 expression.Although Numb,Itch,and seven in absentia homolog-1(Siah-1)have been shown to contribute to the regulation of Notch signaling,their role in colorectal carcinogenesis and tumor progression has not been fully elucidated to date.AIM To evaluate Numb,Itch,and Siah-1 expression in colorectal tumors to clarify their relationship with Notch-1 expression and their role in carcinogenesis and tumor behavior.METHODS Expression of Notch-1,Numb,Itch,and Siah-1 was investigated in 50 colorectal carcinomas,30 adenomas,and 20 healthy colonic tissues by immunohistochemistry and quantitative real-time polymerase chain reaction(PCR)analyses.RESULTS In contrast to Notch-1,which is expressed at higher levels in tumor tissues and adenomas,expression of Numb,Itch,and Siah-1 was stronger and more frequent in normal mucosa(P<0.01).There was a positive correlation between Notch-1 expression and high histological grade,the presence of lymph node metastasis,and advanced-stage tumors,whereas expression of Numb,Itch,and Siah-1 was absent or reduced in tumors with these clinicopathological parameters(P<0.05).In survival analysis,expression of Notch was related to poor prognosis but that of Numb,Itch,and Siah-1 correlated with improved survival(P<0.05).Multivariate analysis revealed Notch-1 expression and loss of Numb expression to be independent prognostic parameters together with lymph node metastasis(P<0.05).CONCLUSION Our findings support the role of Notch-1 in colorectal carcinoma and indicate that loss of Numb,Itch,and Siah-1 expression is associated with carcinogenesis.Our data also suggest that these three proteins might be involved in the Notch-1 pathway during colorectal carcinoma(CRC)progression and might play an essential role in approaches targeting Notch as novel molecular therapies for CRC.展开更多
目的:探讨人参皂苷Rh2对大鼠C6胶质瘤细胞Siah-1、突触素(Synaptophysin)、基质金属蛋白酶-9(MMP-9)血管内皮生长因子(VEGF)表达的影响。方法:将大鼠C6胶质瘤细胞分为对照组、人参皂苷Rh2低剂量组(16μg/m L)、人参皂苷Rh2中剂量组(32μ...目的:探讨人参皂苷Rh2对大鼠C6胶质瘤细胞Siah-1、突触素(Synaptophysin)、基质金属蛋白酶-9(MMP-9)血管内皮生长因子(VEGF)表达的影响。方法:将大鼠C6胶质瘤细胞分为对照组、人参皂苷Rh2低剂量组(16μg/m L)、人参皂苷Rh2中剂量组(32μg/m L)、人参皂苷Rh2高剂量组(48μg/m L),CCK-8法和平板克隆实验检测细胞增殖;流式细胞术检测细胞凋亡;Transwell检测细胞侵袭;实时荧光定量-聚合酶链式反应(qRT-PCR)检测C6胶质瘤细胞中VEGF、Siah-1、Synaptophysin、MMP-9 m RNA表达;蛋白质印迹法(Western blot)检测C6胶质瘤细胞中VEGF、Siah-1、Synaptophysin、MMP-9蛋白表达。结果:与对照组比较,人参皂苷Rh2低剂量组、人参皂苷Rh2中剂量组、人参皂苷Rh2高剂量组大鼠C6胶质瘤细胞OD_(450)值(24 h、48 h)、克隆形成率、细胞侵袭数、VEGF、Synaptophysin、MMP-9 m RNA及蛋白表达降低,细胞凋亡率、Siah-1 m RNA及蛋白表达升高,且呈剂量依赖性(P<0.05)。结论:人参皂苷Rh2可能通过上调Siah-1,下调VEGF、Synaptophysin、MMP-9表达来抑制大鼠C6胶质瘤细胞增殖与侵袭,促进细胞凋亡。展开更多
AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/S...AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Coimmunoprecipitation(co-IP) analysis was performed to examine the binding of Cacy BP/SIP with Skp1. A Cacy BP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1protein expression assessed by Western blot analysis.RESULTS: Cacy BP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while Cacy BP/SIP nuclear translocation was inhibited using si RNA to suppress Cacy BP/SIP expression, cell cycle was clearly inhibited. Cacy BP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of Cacy BP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, Cacy BP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant Cacy BP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus.CONCLUSION: Cacy BP/SIP nuclear translocation contributes to the proliferation of GC cells, and Cacy BP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27Kip1.展开更多
AIM:To investigate the role of nuclear translocation of calcyclin binding protein,also called Siah-1 interacting protein(CacyBP/SIP),in gastric carcinogenesis.METHODS:The expression of CacyBP/SIP protein in gastric ca...AIM:To investigate the role of nuclear translocation of calcyclin binding protein,also called Siah-1 interacting protein(CacyBP/SIP),in gastric carcinogenesis.METHODS:The expression of CacyBP/SIP protein in gastric cancer cell lines was detected by Western blot.Immunofluorescence experiments were performed on gastric cancer cell lines that had been either unstimulated or stimulated with gastrin.To confirm the immunofluorescence findings,the relative abundance of CacyBP/SIP in nuclear and cytoplasmic compartments was assessed by Western blot.The effect of nuclear translocation of CacyBP/SIP on cell proliferation was examined using MTT assay.The colony formation assay was used to measure clonogenic cell survival.The effect of CacyBP/SIP nuclear translocation on cell cycle progression was investigated.Two CacyBP/SIPspecific siRNA vectors were designed and constructed to inhibit CacyBP/SIP expression in order to reduce the nuclear translocation of CacyBP/SIP,and the expression of CacyBP/SIP in stably transfected cells was determined by Western blot.The effect of inhibiting CacyBP/SIP nuclear translocation on cell proliferation was then assessed.RESULTS:CacyBP/SIP protein was present in most of gastric cancer cell lines.In unstimulated cells,CacyBP/SIP was distributed throughout the cytoplasm;while in stimulated cells,CacyBP/SIP was found mainly in the perinuclear region.CacyBP/SIP nuclear translocation generated a growth-stimulatory effect on cells.The number of colonies in the CacyBP/SIP nuclear translocation group was significantly higher than that in the control group.The percentage of stimulated cells in G1phase was significantly lower than that of control cells(69.70%±0.46%and 65.80%±0.60%,control cells and gastrin-treated SGC7901 cells,P=0.008;72.99%±0.46%and 69.36%±0.51%,control cells and gastrin-treated MKN45 cells,P=0.022).CacyBP/SIPsi1effectively down-regulated the expression of CacyBP/SIP,and cells stably transfected by CacyBP/SIPsi1 were then chosen for further cellular assays.In CacyBP/SIPsi1 stably transfected cells,CacyBP/SIP was shown to be distributed throughout the cytoplasm,irregardless of whether they were stimulated or not.After CacyBP/SIP nuclear translocation was reduced,there had no major effect on cell proliferation,as shown by MTT assay.There had no enhanced anchoragedependent growth upon stimulation,as indicated by colony formation in flat plates.No changes appeared in the percentage of cells in G0-G1 phase in either cell line(71.09%±0.16%and 70.86%±0.25%,control cells and gastrin-treated SGC7901-CacyBP/SIPsi1 cells,P=0.101;74.17%±1.04%and 73.07%±1.00%,control cells and gastrin-treated MKN45-CacyBP/SIPsi1cells,P=0.225).CONCLUSION:CacyBP/SIP nuclear translocation promotes the proliferation and cell cycle progression of gastric cancer cells.展开更多
基金Akdeniz University Scientific Research Foundation,Turkey,No.2017040103020.
文摘BACKGROUND The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs,including the colon.Accordingly,studies aimed at developing therapies targeting this pathway in various cancers require the identification of several factors that may play a role in regulating Notch-1 expression.Although Numb,Itch,and seven in absentia homolog-1(Siah-1)have been shown to contribute to the regulation of Notch signaling,their role in colorectal carcinogenesis and tumor progression has not been fully elucidated to date.AIM To evaluate Numb,Itch,and Siah-1 expression in colorectal tumors to clarify their relationship with Notch-1 expression and their role in carcinogenesis and tumor behavior.METHODS Expression of Notch-1,Numb,Itch,and Siah-1 was investigated in 50 colorectal carcinomas,30 adenomas,and 20 healthy colonic tissues by immunohistochemistry and quantitative real-time polymerase chain reaction(PCR)analyses.RESULTS In contrast to Notch-1,which is expressed at higher levels in tumor tissues and adenomas,expression of Numb,Itch,and Siah-1 was stronger and more frequent in normal mucosa(P<0.01).There was a positive correlation between Notch-1 expression and high histological grade,the presence of lymph node metastasis,and advanced-stage tumors,whereas expression of Numb,Itch,and Siah-1 was absent or reduced in tumors with these clinicopathological parameters(P<0.05).In survival analysis,expression of Notch was related to poor prognosis but that of Numb,Itch,and Siah-1 correlated with improved survival(P<0.05).Multivariate analysis revealed Notch-1 expression and loss of Numb expression to be independent prognostic parameters together with lymph node metastasis(P<0.05).CONCLUSION Our findings support the role of Notch-1 in colorectal carcinoma and indicate that loss of Numb,Itch,and Siah-1 expression is associated with carcinogenesis.Our data also suggest that these three proteins might be involved in the Notch-1 pathway during colorectal carcinoma(CRC)progression and might play an essential role in approaches targeting Notch as novel molecular therapies for CRC.
文摘目的:探讨人参皂苷Rh2对大鼠C6胶质瘤细胞Siah-1、突触素(Synaptophysin)、基质金属蛋白酶-9(MMP-9)血管内皮生长因子(VEGF)表达的影响。方法:将大鼠C6胶质瘤细胞分为对照组、人参皂苷Rh2低剂量组(16μg/m L)、人参皂苷Rh2中剂量组(32μg/m L)、人参皂苷Rh2高剂量组(48μg/m L),CCK-8法和平板克隆实验检测细胞增殖;流式细胞术检测细胞凋亡;Transwell检测细胞侵袭;实时荧光定量-聚合酶链式反应(qRT-PCR)检测C6胶质瘤细胞中VEGF、Siah-1、Synaptophysin、MMP-9 m RNA表达;蛋白质印迹法(Western blot)检测C6胶质瘤细胞中VEGF、Siah-1、Synaptophysin、MMP-9蛋白表达。结果:与对照组比较,人参皂苷Rh2低剂量组、人参皂苷Rh2中剂量组、人参皂苷Rh2高剂量组大鼠C6胶质瘤细胞OD_(450)值(24 h、48 h)、克隆形成率、细胞侵袭数、VEGF、Synaptophysin、MMP-9 m RNA及蛋白表达降低,细胞凋亡率、Siah-1 m RNA及蛋白表达升高,且呈剂量依赖性(P<0.05)。结论:人参皂苷Rh2可能通过上调Siah-1,下调VEGF、Synaptophysin、MMP-9表达来抑制大鼠C6胶质瘤细胞增殖与侵袭,促进细胞凋亡。
基金Supported by the National Natural Science Foundation of China,No.81072040the Specialized Research Fund for the Doctoral Program of Ningxia Medical University
文摘AIM: To investigate the mechanism of calcyclin binding protein/Siah-1 interacting protein(Cacy BP/SIP) nuclear translocation in promoting the proliferation of gastric cancer(GC) cells. METHODS: The effect of Cacy BP/SIP nuclear translocation on cell cycle was investigated by cell cycle analysis. Western blot analysis was used to assess the change in expression of cell cycle regulatory proteins and proteasome-mediated degradation of p27Kip1. Coimmunoprecipitation(co-IP) analysis was performed to examine the binding of Cacy BP/SIP with Skp1. A Cacy BP/SIP truncation mutant which lacked the Skp1 binding site was constructed and fused to a fluorescent protein. Subsequently, the effect on Skp1 binding with the fusion protein was examined by co-IP, while localization of fluorescent fusion protein observed by confocal laser microscopy, and change in p27Kip1protein expression assessed by Western blot analysis.RESULTS: Cacy BP/SIP nuclear translocation induced by gastrin promoted progression of GC cells from G1 phase. However, while Cacy BP/SIP nuclear translocation was inhibited using si RNA to suppress Cacy BP/SIP expression, cell cycle was clearly inhibited. Cacy BP/SIP nuclear translocation significantly decreased the level of cell cycle inhibitor p27Kip1, increased Cyclin E protein expression whereas the levels of Skp1, Skp2, and CDK2 were not affected. Upon inhibition of Cacy BP/SIP nuclear translocation, there were no changes in protein levels of p27Kip1 and Cyclin E, while p27Kip1 decrease could be prevented by the proteasome inhibitor MG132. Moreover, Cacy BP/SIP was found to bind to Skp1 by immunoprecipitation, an event that was abolished by mutant Cacy BP/SIP, which also failed to stimulate p27Kip1 degradation, even though the mutant could still translocate into the nucleus.CONCLUSION: Cacy BP/SIP nuclear translocation contributes to the proliferation of GC cells, and Cacy BP/SIP exerts this effect, at least in part, by stimulating ubiquitin-mediated degradation of p27Kip1.
基金Supported by National Natural Science Foundation of China,No.81072040
文摘AIM:To investigate the role of nuclear translocation of calcyclin binding protein,also called Siah-1 interacting protein(CacyBP/SIP),in gastric carcinogenesis.METHODS:The expression of CacyBP/SIP protein in gastric cancer cell lines was detected by Western blot.Immunofluorescence experiments were performed on gastric cancer cell lines that had been either unstimulated or stimulated with gastrin.To confirm the immunofluorescence findings,the relative abundance of CacyBP/SIP in nuclear and cytoplasmic compartments was assessed by Western blot.The effect of nuclear translocation of CacyBP/SIP on cell proliferation was examined using MTT assay.The colony formation assay was used to measure clonogenic cell survival.The effect of CacyBP/SIP nuclear translocation on cell cycle progression was investigated.Two CacyBP/SIPspecific siRNA vectors were designed and constructed to inhibit CacyBP/SIP expression in order to reduce the nuclear translocation of CacyBP/SIP,and the expression of CacyBP/SIP in stably transfected cells was determined by Western blot.The effect of inhibiting CacyBP/SIP nuclear translocation on cell proliferation was then assessed.RESULTS:CacyBP/SIP protein was present in most of gastric cancer cell lines.In unstimulated cells,CacyBP/SIP was distributed throughout the cytoplasm;while in stimulated cells,CacyBP/SIP was found mainly in the perinuclear region.CacyBP/SIP nuclear translocation generated a growth-stimulatory effect on cells.The number of colonies in the CacyBP/SIP nuclear translocation group was significantly higher than that in the control group.The percentage of stimulated cells in G1phase was significantly lower than that of control cells(69.70%±0.46%and 65.80%±0.60%,control cells and gastrin-treated SGC7901 cells,P=0.008;72.99%±0.46%and 69.36%±0.51%,control cells and gastrin-treated MKN45 cells,P=0.022).CacyBP/SIPsi1effectively down-regulated the expression of CacyBP/SIP,and cells stably transfected by CacyBP/SIPsi1 were then chosen for further cellular assays.In CacyBP/SIPsi1 stably transfected cells,CacyBP/SIP was shown to be distributed throughout the cytoplasm,irregardless of whether they were stimulated or not.After CacyBP/SIP nuclear translocation was reduced,there had no major effect on cell proliferation,as shown by MTT assay.There had no enhanced anchoragedependent growth upon stimulation,as indicated by colony formation in flat plates.No changes appeared in the percentage of cells in G0-G1 phase in either cell line(71.09%±0.16%and 70.86%±0.25%,control cells and gastrin-treated SGC7901-CacyBP/SIPsi1 cells,P=0.101;74.17%±1.04%and 73.07%±1.00%,control cells and gastrin-treated MKN45-CacyBP/SIPsi1cells,P=0.225).CONCLUSION:CacyBP/SIP nuclear translocation promotes the proliferation and cell cycle progression of gastric cancer cells.
