下调ADAM17促进奥利沙铂耐药结肠癌细胞对NK细胞杀伤敏感的机制研究

Mechanism of down-regulation of ADAM17 promotes sensitivity of oxaliplatinresistant colon cancer cells to NK cells

目的:探讨ADAM17促进奥利沙铂(L-OHP)耐药结肠癌细胞对NK细胞杀伤敏感的作用机制。方法:免疫组化检测ADAM17在L-OHP敏感及L-OHP耐药结肠癌患者肿瘤组织中的表达;qRT-PCR与Western blot检测ADAM17在L-OHP耐药组织及细胞中的表达;MTT法检测HCT116细胞与HCT116/L-OHP细胞的L-OHP药物敏感性;qRT-PCR与Western blot检测HCT116细胞与HCT116/L-OHP细胞中ADAM17表达。小干扰RNA内源性敲低HCT116/L-OHP细胞中的ADAM17、MICA与MICB,qRT-PCR与Western blot检测ADAM17、MICA与MICB表达,流式细胞术检测MICA与MICB表达,乳酸脱氢酶释放法检测NK92细胞对HCT116/L-OHP细胞的杀伤活性。结果:ADAM17在L-OHP耐药患者组织及细胞中高表达。与HCT116细胞相比,L-OHP处理可提高HCT116/L-OHP细胞的IC50,促进ADAM17表达(P<0.05)。与si-NC组相比,si-ADAM17组HCT116/L-OHP细胞中ADAM17表达降低,MICA与MICB表达升高,NK92细胞杀伤率升高。与si-ADAM7组相比,si-ADAM7+si-MICA组MICA表达降低(P<0.05),si-ADAM7+si-MICB组MICB表达降低(P<0.05),NK92细胞杀伤率降低(P<0.05)。结论:下调ADAM17通过促进MICA与MICB表达增强NK92细胞对HCT116/L-OHP细胞的杀伤活性。

Objective:To explore mechanism of ADAM17 in promoting sensitivity of olisaplatin(L-OHP)-resistant colon cancer cells to killing NK cells.Methods:Immunohistochemistry was performed to detect expression of ADAM17 in colon cancer tissues from patients with L-OHP-sensitive and L-OHP-resistant.qRT-PCR and Western blot were used to detect expression of ADAM17 in L-OHP-resistant tissues and cells;MTT method for detection of L-OHP drug sensitivity in HCT116 cells and HCT116/L-OHP cells;qRT-PCR and Western blot were used to detect expression of ADAM17 in HCT116 cells and HCT116/L-OHP cells.Small interfering RNA endogenously knocked down ADAM17,MICA and MICB in HCT116/L-OHP cells,qRT-PCR and Western blot were employed to detect expressions of ADAM17,MICA and MICB,flow cytometry was used to detect expressions of MICA and MICB,and lactate dehydrogenase release method was used to detect killing activity of NK92 cells against HCT116/L-OHP cells.Results:ADAM17 was overexpressed in tissues and cells of patients with L-OHP resistance.Compared with HCT116 cells,L-OHP treatment could increase IC50 of HCT116/L-OHP cells and promote expression of ADAM17(P<0.05).Compared with si-NC group,expression of ADAM17 in HCT116/L-OHP cells was decreased,expressions of MICA and MICB were increased,and killing rate of NK92 cells was increased in si-ADAM17 group.Compared with si-ADAM7 group,expression of MICA in si-ADAM7+si-MICA group was reduced(P<0.05),expression of MICB in si-ADAM7+si-MICB group was reduced(P<0.05),and killing rate of NK92 cells in these two groups were weakened(P<0.05).Conclusion:Down-regulating ADAM17 enhances killing activity of NK92 cells against HCT116/L-OHP cells by promoting expressions of MICA and MICB.