AIM To determine the potential roles of CD4 and micro RNA(mi R)-145 in gastric cancer.METHODS The levels of CD44 and mi R-145 were determined in gastric cancer cells. Quantitative real-time polymerase chain reaction w...AIM To determine the potential roles of CD4 and micro RNA(mi R)-145 in gastric cancer.METHODS The levels of CD44 and mi R-145 were determined in gastric cancer cells. Quantitative real-time polymerase chain reaction was used to measure to the level of CD44 m RNA. A luciferase reporter assay and western blotting were performed to examine the effect of mi R-145 on CD44 expression. Tumor sphere and MTT assays were carried out to evaluate the self-renewal and chemo-resistance properties of gastric cancer cells.RESULTS The expression of CD44 was greatly increased and mi R-145 was decreased in gastric cancer cells that were highly enriched in cancer stem cells(CSCs). The results demonstrated that mi R-145 regulated CD44 by targeting directly the CD44 3'-untranslated region(3'-UTR). In gastric cancer cells, overexpression of mi R-145 repressed the activity of the CD44 3'-UTR, and disruption of mi R-145/CD44 3'-UTR interactions abrogated the silencing effects. In addition, mi R-145 inhibition stimulated CD44 3'-UTR activity and disruption of mi R-145/CD44 3'-UTR interactions abrogated this stimulatory effect. Enforced CD44 expression greatly increased tumor sphere formation and chemoresistance in gastric cancer cells. Furthermore, the inhibition of CSCs and the chemo-sensitivity of gastric cancer cells treated with mi R-145 were significantly abrogated by overexpression of CD44. CONCLUSION mi R-145 targeting of CD44 plays critical roles in the regulation of tumor growth and chemo-resistance in gastric cancer.展开更多
Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continual...Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continually diversifying cells. This heterogeneity enables the survival of different clones under particular conditions allowing growth at metastatic locations or resistance to chemotherapeutics. Cancer stem cell (CSC) theory completely overturns this traditional understanding of cancer suggesting that only CSCs can self-renew and promote tumor growth. CSCs are relatively refractory to conventional therapies, thus explaining why anti-cancer therapies are far from curative and why relapses of cancer are frequent. The identification of the CSC component of a tumor might, thus, open new therapeutic perspective based on the selective targeting of this small population of cells. In this review we examine the current scientific evidence supporting the existence of CSC in gastric tumors and analyze the main unsolved questions of this difficult field of cancer research.展开更多
Gastric cancer stem-like cells（GCSCs） have been identified to possess the ability of self-renewal and tumor initi-ation.However,the mechanisms involved remain largely unknown.Here,we isolated and characterized the G...Gastric cancer stem-like cells（GCSCs） have been identified to possess the ability of self-renewal and tumor initi-ation.However,the mechanisms involved remain largely unknown.Here,we isolated and characterized the GCSCs by side population（SP） sorting procedure and cultured sphere cells（SC） from human gastric cancer cell lines SGC-7901,BGC-823,MGC-803,HGC-27 and MKN-28.The sorting and culture assay revealed that SP cells proliferated in an asymmetric division manner.In addition,SP cells exhibited a higher potential of spheroid colony formation and greater drug resistance than non-SP cells（NSP）.Moreover,the SC were found with enhanced capabilities of drug resistance in vitro and tumorigenicity in vivo.Sox2 mRNA and protein was highly and significantly overex-pressed in the SP cells and SC.Importantly,downregulation of Sox2 with siRNA obviously reduced spheroid colony formation and doxorubicin efflux,as well as increased apoptosis rate in sphere cells in vitro and suppressed tumori-genicity in vivo.These results suggest that both SP cells and cultured SC enrich with GCSCs and that Sox2 plays a pivotal role in sustaining stem cell properties and might be a potential target for gastric cancer therapy.展开更多
Objective: To investigate the clinical significance of cell adhesive molecule (CD44) expression on periphery blood (PB) of patients with gastric cancer. Methods: Both the level of CD44 and the immunocyte phenotype of ...Objective: To investigate the clinical significance of cell adhesive molecule (CD44) expression on periphery blood (PB) of patients with gastric cancer. Methods: Both the level of CD44 and the immunocyte phenotype of the lymphocytes of 110 patients with gastric cancer and 100 healthy subjects were examined by flow cytometry, and the results were analyzed pathologically and statistically. Results: The mean of the CD44% in PB of the healthy subjects was 46.14±3.4 and there were no statistic differences for their age and sex. Site of tumor growth: The significant difference (P<0.01) was present between the patients with the cardiac part (C) or body of gastric (M+C) cancer and normal individuals. The significant difference (P<0.05) was present between patients with the 3 sites involved gastric cancer and normal individuals. Type of tumor mass: The significant difference (P<0.05) was present between patients with mixed type gastric cancer and normal individuals. Size of tumor mass: The significant difference was present between the normal individuals and patients with gastric cancer > 10 cm mass (P<0.01) and 7–10 cm mass (P<0.05). Degree of tumor differentiation: The significant difference (P<0.01) was present between the patients with low differentiation gastric cancer and normal individuals. The significant difference (P<0.01) was present between patients with metastatic stage: The significant difference (P<0.01) was present lymph node gastric cancer and normal individuals. Clinical between the patients with advanced or relapsed gastric cancer and normal individuals. Age: The significant difference (P<0.01) was present between the gastric cancer patients under 59 years and normal individuals. Conclusion: The increased level of CD44 in the PB of patients with gastric cancer indicated the possible existence of relapse, advance or metastasis of tumors. When the tumor was poorly differentiated and bigger in tumor mass, the level of CD44% would be higher. Examining the level of CD44 by flow cytometry in the periphery blood of patients with gastric cancer was useful for the prognosis.展开更多
基金Supported by Quanzhou excellent personnel training,No.10A16Natural Science Foundation of Fujian Province,No.JA08084Fujian Medical University,No.092D014
文摘AIM To determine the potential roles of CD4 and micro RNA(mi R)-145 in gastric cancer.METHODS The levels of CD44 and mi R-145 were determined in gastric cancer cells. Quantitative real-time polymerase chain reaction was used to measure to the level of CD44 m RNA. A luciferase reporter assay and western blotting were performed to examine the effect of mi R-145 on CD44 expression. Tumor sphere and MTT assays were carried out to evaluate the self-renewal and chemo-resistance properties of gastric cancer cells.RESULTS The expression of CD44 was greatly increased and mi R-145 was decreased in gastric cancer cells that were highly enriched in cancer stem cells(CSCs). The results demonstrated that mi R-145 regulated CD44 by targeting directly the CD44 3'-untranslated region(3'-UTR). In gastric cancer cells, overexpression of mi R-145 repressed the activity of the CD44 3'-UTR, and disruption of mi R-145/CD44 3'-UTR interactions abrogated the silencing effects. In addition, mi R-145 inhibition stimulated CD44 3'-UTR activity and disruption of mi R-145/CD44 3'-UTR interactions abrogated this stimulatory effect. Enforced CD44 expression greatly increased tumor sphere formation and chemoresistance in gastric cancer cells. Furthermore, the inhibition of CSCs and the chemo-sensitivity of gastric cancer cells treated with mi R-145 were significantly abrogated by overexpression of CD44. CONCLUSION mi R-145 targeting of CD44 plays critical roles in the regulation of tumor growth and chemo-resistance in gastric cancer.
文摘Traditionally, the clonal evolution model has been used to explain gastric cancer (GC) growth dynamics. According to this model, GC cells result from multiple mutations over time resulting in a population of continually diversifying cells. This heterogeneity enables the survival of different clones under particular conditions allowing growth at metastatic locations or resistance to chemotherapeutics. Cancer stem cell (CSC) theory completely overturns this traditional understanding of cancer suggesting that only CSCs can self-renew and promote tumor growth. CSCs are relatively refractory to conventional therapies, thus explaining why anti-cancer therapies are far from curative and why relapses of cancer are frequent. The identification of the CSC component of a tumor might, thus, open new therapeutic perspective based on the selective targeting of this small population of cells. In this review we examine the current scientific evidence supporting the existence of CSC in gastric tumors and analyze the main unsolved questions of this difficult field of cancer research.
基金supported in part by the Foundation of State Key Laboratory of Reproductive Medicine,the project funded by the Priority Academic Program Development(PAPD) of Jiangsu Higher Education Institutionsthe National Natural Science Foundation of China(No. 30930080 and 81161120537)
文摘Gastric cancer stem-like cells（GCSCs） have been identified to possess the ability of self-renewal and tumor initi-ation.However,the mechanisms involved remain largely unknown.Here,we isolated and characterized the GCSCs by side population（SP） sorting procedure and cultured sphere cells（SC） from human gastric cancer cell lines SGC-7901,BGC-823,MGC-803,HGC-27 and MKN-28.The sorting and culture assay revealed that SP cells proliferated in an asymmetric division manner.In addition,SP cells exhibited a higher potential of spheroid colony formation and greater drug resistance than non-SP cells（NSP）.Moreover,the SC were found with enhanced capabilities of drug resistance in vitro and tumorigenicity in vivo.Sox2 mRNA and protein was highly and significantly overex-pressed in the SP cells and SC.Importantly,downregulation of Sox2 with siRNA obviously reduced spheroid colony formation and doxorubicin efflux,as well as increased apoptosis rate in sphere cells in vitro and suppressed tumori-genicity in vivo.These results suggest that both SP cells and cultured SC enrich with GCSCs and that Sox2 plays a pivotal role in sustaining stem cell properties and might be a potential target for gastric cancer therapy.
基金the Zhejiang Medical and Health Science Foundation (No. 98001).
文摘Objective: To investigate the clinical significance of cell adhesive molecule (CD44) expression on periphery blood (PB) of patients with gastric cancer. Methods: Both the level of CD44 and the immunocyte phenotype of the lymphocytes of 110 patients with gastric cancer and 100 healthy subjects were examined by flow cytometry, and the results were analyzed pathologically and statistically. Results: The mean of the CD44% in PB of the healthy subjects was 46.14±3.4 and there were no statistic differences for their age and sex. Site of tumor growth: The significant difference (P<0.01) was present between the patients with the cardiac part (C) or body of gastric (M+C) cancer and normal individuals. The significant difference (P<0.05) was present between patients with the 3 sites involved gastric cancer and normal individuals. Type of tumor mass: The significant difference (P<0.05) was present between patients with mixed type gastric cancer and normal individuals. Size of tumor mass: The significant difference was present between the normal individuals and patients with gastric cancer > 10 cm mass (P<0.01) and 7–10 cm mass (P<0.05). Degree of tumor differentiation: The significant difference (P<0.01) was present between the patients with low differentiation gastric cancer and normal individuals. The significant difference (P<0.01) was present between patients with metastatic stage: The significant difference (P<0.01) was present lymph node gastric cancer and normal individuals. Clinical between the patients with advanced or relapsed gastric cancer and normal individuals. Age: The significant difference (P<0.01) was present between the gastric cancer patients under 59 years and normal individuals. Conclusion: The increased level of CD44 in the PB of patients with gastric cancer indicated the possible existence of relapse, advance or metastasis of tumors. When the tumor was poorly differentiated and bigger in tumor mass, the level of CD44% would be higher. Examining the level of CD44 by flow cytometry in the periphery blood of patients with gastric cancer was useful for the prognosis.
