鸟苷酸环化酶C基因沉默对人胃癌裸鼠皮下种植瘤的影响

目的:探讨鸟苷酸环化酶C(GC-C)基因沉默对人胃癌裸鼠皮下种植瘤的影响及其机制.方法:将SGC-7901细胞(SGC-7901组)、空质粒转染的细胞(PRNA组)、GC-C基因稳定沉默的细胞(GC-C-shRNA组)悬液先在裸鼠皮下接种成瘤,再取瘤组织块分别接种到裸鼠皮下,建立3种胃癌裸鼠皮下种植瘤模型.观察裸鼠一般情况、肿瘤的成瘤率、生长速度,描绘肿瘤的生长曲线,计算肿瘤的抑瘤率;采用实时荧光定量PCR(RFQ-PCR),Western blot和免疫组织化学法检测GC-C和趋化因子受体4(CXCR4)在各组移植瘤组织中的表达.结果:与SGC-7901组和PRNA组比较,GC-C-shRNA组裸鼠移植瘤生长速度明显减慢、体积明显变小(抑制率分别为33.7%、33.2%),肿瘤异型性、坏死程度明显降低,差异具有统计学意义(均P<0.05),且移植瘤组织中GC-C和CXCR4 mRNA和蛋白均明显下调(GC-CmRNA:7.47±1.70 vs 11.18±0.60,11.28±0.85;GC-C蛋白:0.52±0.15 vs 1.04±0.19,1.03±0.24;CXCR4蛋白:0.67±0.13 vs 1.02±0.21,1.03±0.23,均P<0.05).结论:GC-C基因稳定沉默在体内能保持稳定,且能抑制裸鼠移植瘤生长,该过程可能与CXCR4下调有关.

GC-C gene silencing inhibits the growth of subcutaneously implanted gastric tumors in nude mice

AIM:To study the effect of GC-C gene silencing on the biological behaviors of subcutaneously implanted gastric tumors and to explore the possible mechanisms involved.METHODS:Non-transfected SGC-7901 cells(SGC-7901 group),SGC-7901 cells transfected cell with an empty plasmid(PRNA group),and those transfected with a shRNA targeting the GC-C gene(GC-C-shRNA group) were sub-cutaneously inoculated into nude mice.Then,the histologically intact xenograft tissues were subcutaneously transplanted to nude mice to observe the condition of nude mice and determine the rate of tumor survival and growth velocity.The levels of GC-C mRNA and protein were determined by RFQ-PCR and Western blot,respectively.The heteromorphism and necrosis of tumor cells were observed after HE staining.The expression of CXCR4 protein was detected by Western blot and immunohistochemistry.RESULTS:The rate of tumor survival and the condition of nude mice did not differ significantly among the three groups.Compared to the SGC-7901 group and PRNA group,the tumors grew more slowly and became smaller in the GC-C-shRNA group(all P < 0.05).The reduced rate of tumor growth velocity and volume in the GC-C-shRNA group were 33.7% and 33.2%,respectively,and GC-C gene silencing efficiency was 66.8% and 64.4%,respectively(P < 0.05).The expression of GC-C protein decreased by 50.0% and 49.6%,respectively(P < 0.05),and the degree of tumor heteromorphism and necrosis and expression of CXCR4 protein in the GC-CshRNA group decreased obviously(all P < 0.05).CONCLUSION:GC-C gene silencing slows the growth velocity of gastric tumors in vivo possibly in a CXCR4-dependent manner.