miR-21促进肺癌EGFR-TKI耐药细胞株上皮——间质细胞转化的研究

MiR-21 Promotes Epithelial to Mesenchymal Transition in EGFR-TKI Resistant Lung Cancer Cells

[目的]研究miR-21是否可以调控上皮—间质转化(EMT)而参与肺癌获得性耐药。[方法]使用HCC827细胞(EGFR基因19外显子缺少的肺腺癌细胞株),在此细胞的基础上培养吉非替尼耐药细胞株HCC827/GR。检测耐药细胞株中miR-21的表达,同时观察耐药细胞的形态变化,及在耐药细胞株中抑制miR-21表达后检测耐药细胞株的侵袭能力及EMT相关蛋白E-cadherin和Vimentin的表达。[结果]与敏感细胞株HCC827相比,HCC827/GR细胞株对吉非替尼的耐药倍数约为100倍;同时在耐药细胞株中我们发现miR-21较敏感株表达增高约5.3倍,同时细胞形态发生了明显变化。通过检测EMT相关蛋白,我们发现耐药细胞株中间质相关蛋白Vimentin明显高表达,而上皮相关蛋白E-cadherin明显低表达,当miR-21被抑制后,耐药细胞株侵袭能力下降,同时Vimentin表达量下降,而E-cadherin表达量增高。[结论]miR-21可能通过促进EMT参与肺癌EGFR-TKI的获得性耐药。

[Purpose]To investigate the association of epithelial mesenchymal transition and miR-21 in EGFR-TKI acquired resistant cell line—HCC827/GR.[Methods] Resistant cell line HCC827/GR based on EGFR-TKI sensitive cell line HCC827（ exon 19 deletion in EGFR gene） was established. The expression of miR-21 was detected by RTPCR,meanwhile the morphological change was observed. MiR-21 was inhibited in HCC827/GR and invasion capacity and EMT related biomarkers such as E-cadherin and Vimentin were detected by Western blot. [Results] Compared with HCC827,HCC827/GR demonstrated 100 times resistance to EGFR-TKI. Moreover,we observed that miR-21 was more than 5 folds higher in HCC827/GR compared with HCC827,and HCC827/GR demonstrated mesenchymal phenotype. We also found that expression of Vimentin increased while expression of E-cadherin decreased compared with HCC827. When miR-21 was inhibited in HCC827/GR,expression of Vimentin decreased while expression of E-cadherin increased.[Conclusion] MiR-21 may promote EMT in lung cancer,which contributes to EGFR-TKI acquired resistance.