Downregulation of miRNA-21 and cancer stem cells after chemotherapy results in better outcome in breast cancer patients
Shailendra Dwivedi, Puneet Pareek, Jeewan Ram Vishnoi, Praveen Sharma, Sanjeev Misra
Abstract
Epigenetic modifications have been observed as a decline in miRNA-21 expression and breast cancer stem cell (CSC) population after 3 cycles of standard chemotherapy. The epigenetic response (miRNAs expression) and CSCs are also correlated in patients with Breast Cancer. In patients who tolerated chemotherapy well, miRNA-21 (non-coding RNA) expression decreased significantly after three cycles of chemotherapy. The miRNA-21 expression in breast cancer tissue was quantified by quantitative PCR (real-time PCR) using the standard protocol. In addition, breast CSCs (CD44+/CD24-) were also decreased in these patients. The miRNA-21 regulates cell division, proliferation, and autophagy of cancerous cells (as it targets phosphatase and tensin homolog/AKT/transcription factor EB/programmed cell death 4/autophagy-related protein 5 and chemotherapy also produces similar effects), thereby contributing to these benefits. Therefore, when all of the targets on genes have been explored by mimic miRNA, chemotherapy combined with anti-miRNA21 therapy may prove useful in the care of cancer patients.