新型钙离子通道蛋白TRPV6在胃癌组织中的表达及其临床意义

A novel transient receptor potential calcium channel subfamily V member 6(TRPV6):Its expression and clinical significance in stomach cancer

目的:探究新型钙离子通道蛋白TRPV6在胃癌中的表达及其临床意义。方法:收集2010年5月至2013年3月在我院行手术切除并经病理证实的胃癌组织和相应的癌旁组织标本各65份,采用免疫组化SP法检测胃癌及癌旁组织中TRPV6蛋白的表达;以不同浓度的TRPV6拮抗剂2-氨基乙酯二苯基硼酸(2-amino ethyl two phenyl boronic acid,2-APB)处理胃癌MGC-803细胞,分别采用CCK-8法、流式细胞术和Transwell法检测胃癌MGC-803细胞的增殖、细胞凋亡和迁移能力,采用Western blotting检测细胞中TRPV6、AKT/p-AKT和p-GSK3β蛋白的表达。结果:与癌旁组织相比,胃癌组织中TRPV6蛋白的阳性表达率明显增高[95.4%(62/65)vs 36.9%(24/65),P<0.01],且其表达水平与瘤块大小、淋巴结及远处转移和DUKES分期有关(P<0.05)。2-APB以剂量和时间依赖方式显著抑制胃癌细胞MGC-803的增殖,诱导其凋亡,并使胃癌细胞迁移力减弱(P<0.05)。2-APB明显下调胃癌细胞MGC-803中TRPV6、p-AKT和p-GSK3β蛋白的表达(P<0.05)。结论:TRPV6在胃癌组织中高表达,以2-APB拮抗TRPV6蛋白则显著抑制MGC-803细胞的增殖和迁移能力并诱导细胞凋亡,其机制可能与下调p-AKT/GSK3β信号通路有关。

Objective: To study the expression and putative role of a novel transient receptor potential calcium channel subfamily V member 6( TRPV6) in stomach cancer. Methods: Sixty-five pairs of tumor and surrounding tissue specimens were collected from patients with pathologically confirmed stomach cancer who underwent surgical resection in our hospital between May,2010 and March,2013. TRPV6 protein in these specimens was assessed by immunohistochemical SP staining. To evaluate the putative functional role for TRPV6 in stomach cancer,human stomach cancer MGC-803 cells were treated with 2-amino ethyl two phenyl boronic acid( 2-APB),a TRPV6 channel blocker. After treatment,cell proliferation,apoptosis and migration were assessed by CCK-8 assay,flow cytometry and transwell assay,respectively,and TRPV6,AKT / p-AKT,p-GSK3 protein contents were analyzed by Western blotting. Results: TRPV6 protein was detected in95. 4%( 62 /65) of cancerous tissue specimens but only in 36. 9%( 24 /65) of the corresponding non-cancerous tissue specimens( P < 0. 01). Immunoreactive TRPV6 signal was positively associated with the tumor size,lymph,distant metastasis and Dukes stage( P < 0. 05). The TRPV6 blocker 2-APB significantly inhibited MGC-803 cell proliferation,induced MGC-803 cell apoptosis and inhibited MGC-803 cell migration( P < 0. 05). Moreover,2-APB treatment resulted in significant decreases in TRPV6,p-AKT,and p-GSK3β proteins in a dose-dependent manner in MGC-803 cells( P <0. 05). Conclusions: TRPV6 is highly expressed in stomach cancer,where it promotes cancer cell proliferation and inhibits cancer cell apoptosis. Down-regulation of p-AKT,p-GSK-3 β protein expressions may be possible mechanisms underlying the tumorigenic activity of TRPV6.