miR-638 Serves as a Biomarker of 5-Fluorouracil Sensitivity to Neoadjuvant Chemotherapy in Breast Cancer
- Author:
Bin WANG
1
;
Kun WANG
;
Jian YU
;
Xiao-meng HAO
;
Yu-lu LIU
;
Ai-Yan XING
Author Information
- Publication Type:Original Article
- From:Journal of Breast Cancer 2022;25(3):193-206
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:Neoadjuvant chemotherapy (NAC) is widely used to treat breast cancer (BC). The prediction and evaluation of chemotherapy responses remains a significant challenge.
Methods:MicroRNAs (miRNAs) play a crucial role in cancer drug resistance. We used a miRNA microarray and identified that miR-638 is downregulated in chemoresistant cases.However, the exact role of miR-638 and the underlying mechanisms of chemoresistance remain unclear. Using real-time quantitative reverse transcription polymerase chain reaction, we found significant downregulation of miR-638 in chemoresistant patients compared with chemosensitive patients. To explore the function of miR-638, we overexpressed and inhibited miR-638 expression in MDA-MB-231 and MCF-7 cells by transfecting them with miR-638 mimics and miR-638 inhibitor, respectively. Cell proliferation and apoptosis were measured using MTS and flow cytometry, respectively. A minimal patient-derived xenograft (MiniPDX™) model was established to evaluate the chemosensitivity to different drugs.
Results:The results showed that cell proliferation decreased and cell apoptosis increased in cells transfected with the miR-638 mimic, and cell proliferation and apoptosis were reversed with transfection of miR-638 inhibitor compared with the control group. Among patients who received 5-fluorouracil (5-FU), miR-638 expression levels were lower in the chemoresistant group than in the chemosensitive group. The MiniPDX™ model showed that MDA-MB-231 cells overexpressing miR-638 were more susceptible to 5-FU treatment in vivo.
Conclusion:We provided evidence of acquired resistance to 5-FU caused by miR-638 deficiency. Alterations in miR-638 may be used with 5-FU chemotherapy during NAC for BC.
