冬凌草甲素下调N-乙酰氨基半乳糖转移酶14(pp-GalNAc-T14)表达对肾癌细胞的体外抑制作用

The inhibitory mechanism of down-regulation expression of pp-GalNAc-T14 by oridonin on human renal carcinoma cells in vitro

目的探讨冬凌草甲素下调N-乙酰氨基半乳糖转移酶14(polypeptide N-acetylgalactosaminy-transferase 14,pp-GalNAc-T14)表达对人肾癌细胞的体外抑制作用。方法收集20例根治性肾癌切除标本的肾癌组织和相对应的癌旁正常组织,用RT-PCR法检测肾癌组织和癌旁正常肾组织中pp-GalNAc-T14mRNA的表达情况;用单四唑(MTT)法观察冬凌草甲素对该细胞系(786-0人肾透明细胞癌细胞系)的抑制杀伤效果,并运用RT-PCR法检测用药前后pp-GalNAc-T14mRNA的表达情况。结果 (1)肾癌组织和正常肾组织中pp-GalNAc-T-14mRNA均有表达,扫描定量显示pp-GalNAc-T14mRNA的表达在肾癌组织中较正常肾组织高34.91%(P<0.05)。(2)冬凌草甲素作用于786-0细胞后,细胞中pp-GalNAc-T14表达较空白对照组24h下降15.98%、48h下降44.30%、72h下降58.61%,差异均有统计学意义(P<0.05)。(3)冬凌草甲素可以抑制肾癌细胞的增殖,随着冬凌草甲素剂量的增加和作用时间的延长,其抑制细胞增殖作用逐渐增强,呈明显的时间剂量依赖性。16μmol/L的冬凌草甲素引起的生长抑制明显高于8μmol/L的抑制率(P<0.05),最高可达90%以上。结论 pp-GalNAc-T14通路与肾癌的发生可能有关;冬凌草甲素可以下调O-糖链的起始糖基化转移酶pp-GalNAc-T14的表达,产生抑制肾癌细胞的作用;冬凌草甲素可能成为RCC治疗的新策略。

Objective To investigate the inhibitory mechanism of down-regulation expression of polypeptide N-acetylgalactosaminyl-transferase 14（pp-GalNAc-T14） by oridonin on human renal carcinoma cells in vitro.Methods The expression of pp-GalNAc-T14 mRNA was detected by reverse-transcribed polymerase chain reaction（RT-PCR） in 20 resected renal cancer tissue samples and matched normal paraneoplastic tissues.After treated with different concentrations of oridonin,inhibition of human renal cancer cell line（786-0） growth was examined by MTT assay.Then levels of pp-GalNAc-T14 mRNA before and after oridonin treatment was detected by RT-PCR.Results（1） pp-GalNAc-T14 mRNA was detectable in both renal cell carcinoma tissues and matched normal tissues.Compared with the normal control samples,a 34.91% increase of pp-GalNAc-T14 expression in the renal cell carcinoma tissues was observed（P0.05）.（2） At 24 hours,48 hours and 72 hours after oridonin treatment in the 786-0 cells,expression of pp-GalNac-T14 mRNA significantly decreased 15.98%,44.30% and 58.61% respectively,compared with control cells（P0.05）.（3）The growth and proliferation of human renal cell carcinoma cell line 786-0 could be inhibited by oridonin and showed time-and dose-dependent.Conclusions Oridonin inhibit growth of renal cell carcinoma cells through down-regulating the expression of pp-GalNAc-T14 and may be used as an anti-tumor medicine in the chemotherapy of renal cell carcinoma.