The function role of miR-181a in chemosensitivity to adriamycin by targeting Bcl-2 in low-invasive breast cancer cells.

miR-181a is involved in immunity, metabolism, tumor suppression or carcinogenesis reported by many other studies. However, its role in the development of chemosensitivity to adriamycin in low-invasive breast cancer cells remains unclear. The aim of this study is to define the function role of miR-181a in promoting the efficacy of adriamycin-based neoadjuvant chemotherapy. Cell survival analysis was detected by Cell Counting Kit-8 assay. Apoptotic cells were quantitatively detected using FITC Annexin V apoptosis Detection Kit I. Bcl-2 protein expression was measured by western blot. Luciferase reporter vector with the putative BCL-2 3' untranslated region (3'UTR) was constructed to explore whether BCL-2 was a direct target gene of miR-181a. Real-time PCR was performed to test the expression of miR-181a and Bcl-2 in the selected breast cancer tissue samples. The down-regulation of miR-181a decreased adriamycin-induced apoptosis in MCF-7 cells. Transfected with miR-181a mimic in cells resulted in the decreased expression of Bcl-2. The alteration of miR-181a expression did not significantly affect the chemosensitivity to adriamycin in MCF-7 and MCF-7/ADR cells with genetic knockout of Bcl-2. miR-181a may suppress Bcl-2 expression by forming imperfect base pairing with the 3'UTR of Bcl-2 gene such that a negative relationship between miR-181a and Bcl-2 in MCF-7 and MCF-7/ADR cells is observed. At least in part, the detection of miR-181a may direct the clinical medication in patients with neoadjuvant chemotherapy because of miR-181a enhanced adriamycin-induced apoptosis via targeting Bcl-2.

Zhu Y ，Wu J ，Li S ，Ma R ，Cao H ，Ji M ，Jing C ，Tang J ... -  《-》

MicroRNA-34a modulates chemosensitivity of breast cancer cells to adriamycin by targeting Notch1.

MicroRNA-34a (miR-34a) as a tumor suppressor has been reported in many other studies. However, its role in modulating the sensitivity of breast cancer cells to adriamycin (ADR) remains unclear. The aim of this study is to evaluate the role of miR-34a in the sensitivity of breast cancer cells to ADR. The role of miR-34a in breast cancer cells was detected using MTT assay, flow cytometry assay, real-time PCR and Western blot, etc. The association of miR-34a and Notch1 was analyzed by dual-luciferase reporter assay and Notch1-siRNA technology. Real-time PCR assay was performed to test the expression of miR-34a and Notch1 in 38 selective breast cancer tissue samples. Ectopic overexpression of miR-34a could sensitize MCF-7 breast cancer cells to ADR. MiR-34a mimic could inhibit the luciferase activity of the construct containing wild-type 3' UTR of Notch1 in MCF-7/ADR cells. Notch1-siRNA could partially reverse the effect of miR-34a inhibitor in inducing chemoresistance of MCF-7 cells to ADR. Further, there was an inverse association between Notch1 and miR-34a expression in breast cancer. Dysregulation of miR-34a plays critical roles in the acquired ADR resistance of breast cancer, at least in part via targeting Notch1.

Li XJ ，Ji MH ，Zhong SL ，Zha QB ，Xu JJ ，Zhao JH ，Tang JH ... -  《-》

Upregulation of miR-195 increases the sensitivity of breast cancer cells to Adriamycin treatment through inhibition of Raf-1.

Yang G ，Wu D ，Zhu J ，Jiang O ，Shi Q ，Tian J ，Weng Y ... -  《-》

MiR-181a enhances drug sensitivity in mitoxantone-resistant breast cancer cells by targeting breast cancer resistance protein (BCRP/ABCG2).

Jiao X ，Zhao L ，Ma M ，Bai X ，He M ，Yan Y ，Wang Y ，Chen Q ，Zhao X ，Zhou M ，Cui Z ，Zheng Z ，Wang E ，Wei M ... -  《-》

miR-181a sensitizes a multidrug-resistant leukemia cell line K562/A02 to daunorubicin by targeting BCL-2.

Li H ，Hui L ，Xu W 《-》