PIAS1对裸鼠胃癌种植瘤模型肿瘤细胞增殖的影响及机制研究

Effect of PIAS1 on proliferation and mechanism in model of gastric cancer implantation tumor of nude mouse

目的通过检测信号转导与转录激活子1(STAT1)的活化抑制蛋白(PIAS1)在胃癌细胞株中的表达水平,分析其与胃癌细胞增殖及肿瘤微环境的关系,为胃癌的诊治提供新的靶点。方法构建慢病毒携载PIAS1基因(LV-EGFP-PIAS1)胃癌细胞株SGC-7901,检测PIAS1的表达水平及细胞增殖率。收集LV-EGFP-PIAS1胃癌细胞、LV-EGFP-native空白细胞和对照SGC-7901细胞种植于裸鼠皮下。观察肿瘤体积,通过免疫组织化学法测定增殖细胞核抗原(PCNA)、低氧诱导因子-1α(HIF-1α)、CD34、F4-80的表达水平,计算各组间肿瘤微环境转移(TMEM)结构的数目,应用统计学软件分析各指标表达水平的差异。结果Western blotting测定结果显示,LV-EGFP-PIAS1胃癌细胞株SGC-7901中PIAS1呈高表达,并且细胞增殖率相较于LV-EGFP-native空白组及对照组降低,差异有统计学意义(P<0.05)。裸鼠种植瘤模型显示,相较于LV-EGFP-native空白组及对照组,LV-EGFP-PIAS1转染组的肿瘤体积明显减小,且PCNA、HIF-1α蛋白表达水平明显降低。肿瘤组织TMEM计数结果显示,LV-EGFP-PIAS1转染组为(2.83±0.93)个,少于LV-EGFP-native空白组(3.83±0.83)个和对照组(3.91±0.99)个,差异有统计学意义(P<0.05)。上述各指标在LV-EGFP-native空白组及对照组之间的差异均无统计学意义(P均>0.05)。结论PIAS1参与了胃癌细胞的增殖过程,并可抑制肿瘤的发生、发展,其机制可能为通过调控HIF-1α而改变肿瘤的微环境结构。PIAS1可能成为胃癌治疗的新靶点。

Objective An attempted is made to detect the up-regulation of protein inhibitor of activated STAT1(PIAS1)in gastric cancer cell lines and analyze its relationship with gastric cancer cell proliferation and tumor microenvironment,so as to provide new targets for the diagnosis and treatment of gastric cancer.Methods Lentivirus carrying PIAS1 gene(LV-EGFP-PIAS1)was constructed to transfer gastric cancer cell line SGC-7901,and the expression and proliferation rate of gastric cells were analyzed.LV-EGFP-PIAS1,LV-EGFP-native transferred cells,and control SGC-7901 cells were collected and planted under the skin of nude mice.The tumor volume,the expression of PCNA,HIF-1α,CD34,and F4-80 proteins were observed by utilizing the immunohistochemical method.The number of tumor microenvironment of metastasis(TMEM)structures in each group was studied,and the differences in expression were statistically analyzed.Results The Western blotting results showed that PIAS1 was highly expressed in the constructed LV-EGFP-PIAS1 gastric cancer cell line SGC-7901,and the cell proliferation rate was lower than that in the LV-EGFP-native transferred group and the control group,with statistically significant differences(P<0.05).The implanted tumor model of nude mouse showed that the tumor volume of the LV-EGFP-PIAS1 transferred group,the levels of PCNA,and the protein expression of HIF-1αwere significantly lower than those of the LV-EGFP-native transferred group and the control group.In addition,the TMEM count of the tumor tissue of the LV-EGFP-PIAS1 transferred group(2.83±0.93),were decreased when compared with those of the LV-EGFP-native transferred group and the control group(3.83±0.83,3.91±0.99),respectively,with significant differences(P<0.05).However,there are no statistically significant differences in the above indicators between the LV-EGFP-native transferred group and the control group(P>0.05).Conclusions PIAS1 is involved in the proliferation of gastric cancer cells and the inhibition of tumor development.Its mechanism may be involved in the regulation of HIF-1αto change the tumor microenvironment structure,which may be a new target for the treatment of gastric cancer.