CAJ | 학술논문

背景与目的：以吉西他滨为基础的联合用药在转移性乳腺癌中展示出很好的临床疗效和安全性，但耐药的出现导致治疗失败。MicroRNA是一类非编码小分子RNA，起到类似癌基因或抑癌基因的作用。虽然肿瘤中关于化疗药物耐药的机制报道很多，但microRNA异常表达与耐药之间的关系及机制还不十分清楚。本研究旨在探讨microRNA-21在乳腺癌吉西他滨耐药中的作用及其可能机制。方法：采用低浓度持续诱导MDA-MB-231细胞的方式构建人乳腺癌耐吉西他滨细胞株，药物敏感性差异达10倍以上，继而通过实时荧光定量PCR(real-time PCR，RT-PCR)、CCK-8、蛋白[质]印迹法(Western blot)、转染、划痕和Transwell等实验分别检测microRNA-21对药物的敏感性及上皮-间充质转化(epithelial-mesenchymal transition，EMT)标志物的影响。结果：在乳腺癌吉西他滨耐药细胞株中存在EMT现象，相比亲代细胞，microRNA-21呈高表达，并与吉西他滨敏感性呈负相关。转染microRNA-21的抑制剂和mimic可以分别下调和上调microRNA-21表达，同时EMT现象和药物敏感性也发生了相应的变化。结论：MicroRNA-21可能通过诱导肿瘤细胞的EMT发生而介导乳腺癌对吉西他滨的耐药。
배경여목적：이길서타빈위기출적연합용약재전이성유선암중전시출흔호적림상료효화안전성，단내약적출현도치치료실패。MicroRNA시일류비편마소분자RNA，기도유사암기인혹억암기인적작용。수연종류중관우화료약물내약적궤제보도흔다，단microRNA이상표체여내약지간적관계급궤제환불십분청초。본연구지재탐토microRNA-21재유선암길서타빈내약중적작용급기가능궤제。방법：채용저농도지속유도MDA-MB-231세포적방식구건인유선암내길서타빈세포주，약물민감성차이체10배이상，계이통과실시형광정량PCR(real-time PCR，RT-PCR)、CCK-8、단백[질]인적법(Western blot)、전염、화흔화Transwell등실험분별검측microRNA-21대약물적민감성급상피-간충질전화(epithelial-mesenchymal transition，EMT)표지물적영향。결과：재유선암길서타빈내약세포주중존재EMT현상，상비친대세포，microRNA-21정고표체，병여길서타빈민감성정부상관。전염microRNA-21적억제제화mimic가이분별하조화상조microRNA-21표체，동시EMT현상화약물민감성야발생료상응적변화。결론：MicroRNA-21가능통과유도종류세포적EMT발생이개도유선암대길서타빈적내약。
Background and purpose:Gemcitabine-based chemotherapy has been shown to have signiifcant activity and favourable safety in metastatic breast cancer patients, but the effectiveness is limited due to drug resistance. MicroRNAs are a family of small non-coding RNA molecules, acting as oncogenes or tumor suppressors. Although various mechanisms of chemoresistance have been uncovered, the aberrant microRNA expression and its relationship with drug resistance of breast cancer are still unclear. This study explored the potential role and underlying mechanism of microRNA-21 in gemcitabine resistant breast cancer. Methods:MDA-MB-231 cells were continuously exposed to the increasing concentrations of gemcitabine to induce drug resistance to gemcitabine, which was 10 times more resis-tant. Then multiple methods were used including real-time PCR (RT-PCR), CCK-8, Western blot, transfection, wound healing and Transwell assay to observe the effect of microRNA-21 on epithelial-mesenchymal transition (EMT) and chemosensitivity. Results:The expression of microRNA-21 was up-regulated in gemcitabine resistant breast cancer cell line and inversely correlated with gemcitabine sensitivity. Manipulation of microRNA-21 status could change microR-NA-21 level, and could result in corresponding changes in EMT status and drug sensitivity. Conclusion:MicroRNA-21 induces gemcitabine resistance possibly via EMT process in breast cancer.