AIM: To explore the effects of siRNA silencing of PIK3CA on proliferation, migration and invasion of gastric cancer cells and to investigate the underlying mechanisms. METHODS: The mutation of PIK3CA in exons 9 and 20...AIM: To explore the effects of siRNA silencing of PIK3CA on proliferation, migration and invasion of gastric cancer cells and to investigate the underlying mechanisms. METHODS: The mutation of PIK3CA in exons 9 and 20 of gastric cancer cell lines HGC-27, SGC-7901, BGC-823, MGC-803 and MKN-45 was screened by polymerase chain reaction (PCR) followed by sequencing. BGC-823 cells harboring no mutations in either of the exons, and HGC-27 cells containing PIK3CA mutations were employed in the current study. siRNA targeting PIK3CA was chemically synthesized and was transfect- ed into these two cell lines in vitro . mRNA and protein expression of PIK3CA were detected by real-time PCR and Western blotting, respectively. We also measured phosphorylation of a serine/threonine protein kinase (Akt) using Western blotting. The proliferation, migration and invasion of these cells were examined separately by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltet-razolium bromide (MTT), wound healing and Transwell chambers assay. RESULTS: The siRNA directed against PIK3CA effectively led to inhibition of both endogenous mRNA and protein expression of PIK3CA, and thus significantly down-regulated phosphorylation of Akt (P < 0.05). Furthermore, simultaneous silencing of PIK3CA resulted in an obvious reduction in tumor cell proliferation activity, migration and invasion potential (P < 0.01). Intriguing, mutant HGC-27 cells exhibited stronger invasion ability than that shown by wild-type BGC-823 cells. Knockdown of PIK3CA in mutant HGC-27 cells contributed to a reduction in cell invasion to a greater extent than in non-mutant BGC-823 cells. CONCLUSION: siRNA mediated targeting of PIK3CA may specifically knockdown the expression of PIK3CA in gastric cancer cells, providing a potential implication for therapy of gastric cancer.展开更多
目的研究PTEN基因与宫颈癌细胞增殖能力的关系,以探索PTEN基因在宫颈癌发生发展中的可能作用及其机制。方法 Western blot检测PTEN基因在宫颈癌细胞系HeLa、SiHa、C33A和CasKi中的表达。利用脂质体法将人工过表达PTEN载体转染低表达PTE...目的研究PTEN基因与宫颈癌细胞增殖能力的关系,以探索PTEN基因在宫颈癌发生发展中的可能作用及其机制。方法 Western blot检测PTEN基因在宫颈癌细胞系HeLa、SiHa、C33A和CasKi中的表达。利用脂质体法将人工过表达PTEN载体转染低表达PTEN的宫颈癌细胞系HeLa和C33A,通过MTT方法观察转染后PTEN过表达对宫颈癌细胞增殖的影响。采用多功能过程参数分析仪,检测转染PTEN基因后宫颈癌细胞培养基中乳酸、葡萄糖及谷氨酰胺的含量,观察PTEN基因过表达对宫颈癌细胞代谢的影响。Western blot检测PTEN过表达后宫颈癌细胞中丙酮酸激酶(PKM2)、6-磷酸果糖激酶2(PFKFB3)、谷氨酰胺酶(GLS)、AKT和磷酸化的AKT(pAKT)表达情况。结果与正常宫颈上皮细胞相比,PTEN基因在4种宫颈癌细胞系中低表达。与对照组相比,过表达PTEN的HeLa和C33A细胞克隆中,PTEN基因的水平明显升高。细胞计数和MTT法也显示,过表达PTEN能够明显抑制肿瘤细胞的增殖速率(P<0.05);过表达PTEN基因的细胞培养液中葡萄糖及谷氨酰胺含量显著增多,但乳酸含量减少;同时还发现PTEN抑制了AKT的磷酸化水平并使PKM2、PFKFB3及GLS的表达水平降低。结论 PTEN基因可通过AKT途径调节细胞代谢,从而调节宫颈癌细胞的增殖。PTEN基因有可能成为宫颈癌的诊断和治疗的新靶点。展开更多
基金Supported by Natural Science Foundation of Hunan Province, No.09JJ3060Health Bureau Fund of Guangzhou, No.201102A213006Education Bureau Fund of Guangzhou, No.10A186
文摘AIM: To explore the effects of siRNA silencing of PIK3CA on proliferation, migration and invasion of gastric cancer cells and to investigate the underlying mechanisms. METHODS: The mutation of PIK3CA in exons 9 and 20 of gastric cancer cell lines HGC-27, SGC-7901, BGC-823, MGC-803 and MKN-45 was screened by polymerase chain reaction (PCR) followed by sequencing. BGC-823 cells harboring no mutations in either of the exons, and HGC-27 cells containing PIK3CA mutations were employed in the current study. siRNA targeting PIK3CA was chemically synthesized and was transfect- ed into these two cell lines in vitro . mRNA and protein expression of PIK3CA were detected by real-time PCR and Western blotting, respectively. We also measured phosphorylation of a serine/threonine protein kinase (Akt) using Western blotting. The proliferation, migration and invasion of these cells were examined separately by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltet-razolium bromide (MTT), wound healing and Transwell chambers assay. RESULTS: The siRNA directed against PIK3CA effectively led to inhibition of both endogenous mRNA and protein expression of PIK3CA, and thus significantly down-regulated phosphorylation of Akt (P < 0.05). Furthermore, simultaneous silencing of PIK3CA resulted in an obvious reduction in tumor cell proliferation activity, migration and invasion potential (P < 0.01). Intriguing, mutant HGC-27 cells exhibited stronger invasion ability than that shown by wild-type BGC-823 cells. Knockdown of PIK3CA in mutant HGC-27 cells contributed to a reduction in cell invasion to a greater extent than in non-mutant BGC-823 cells. CONCLUSION: siRNA mediated targeting of PIK3CA may specifically knockdown the expression of PIK3CA in gastric cancer cells, providing a potential implication for therapy of gastric cancer.
文摘目的研究PTEN基因与宫颈癌细胞增殖能力的关系,以探索PTEN基因在宫颈癌发生发展中的可能作用及其机制。方法 Western blot检测PTEN基因在宫颈癌细胞系HeLa、SiHa、C33A和CasKi中的表达。利用脂质体法将人工过表达PTEN载体转染低表达PTEN的宫颈癌细胞系HeLa和C33A,通过MTT方法观察转染后PTEN过表达对宫颈癌细胞增殖的影响。采用多功能过程参数分析仪,检测转染PTEN基因后宫颈癌细胞培养基中乳酸、葡萄糖及谷氨酰胺的含量,观察PTEN基因过表达对宫颈癌细胞代谢的影响。Western blot检测PTEN过表达后宫颈癌细胞中丙酮酸激酶(PKM2)、6-磷酸果糖激酶2(PFKFB3)、谷氨酰胺酶(GLS)、AKT和磷酸化的AKT(pAKT)表达情况。结果与正常宫颈上皮细胞相比,PTEN基因在4种宫颈癌细胞系中低表达。与对照组相比,过表达PTEN的HeLa和C33A细胞克隆中,PTEN基因的水平明显升高。细胞计数和MTT法也显示,过表达PTEN能够明显抑制肿瘤细胞的增殖速率(P<0.05);过表达PTEN基因的细胞培养液中葡萄糖及谷氨酰胺含量显著增多,但乳酸含量减少;同时还发现PTEN抑制了AKT的磷酸化水平并使PKM2、PFKFB3及GLS的表达水平降低。结论 PTEN基因可通过AKT途径调节细胞代谢,从而调节宫颈癌细胞的增殖。PTEN基因有可能成为宫颈癌的诊断和治疗的新靶点。
