Title:Downregulation of miRNA-14669 Reverses Vincristine Resistance in Colorectal
Cancer Cells through PI3K/AKT Signaling Pathway
Volume: 17
Issue: 2
Author(s): Weihua Dong, Fang Wang, Qingyu Liu, Tianyun Wang*, Yun Yang, Peixia Guo, Xiang Li and Bingdi Wei
Affiliation:
- Department of Biochemistry and Molecular Biology, Basic Medical School, Xinxiang Medical University, Jinsui
Road, Henan, P.R. China
- Henan Key Laboratory of Recombinant Pharmaceutical Protein Expression System,
Xinxiang Medical University, Jinsui Road, Henan, P.R. China
Keywords:
miRNA, identify, drug resistance, colorectal cancer, reverse, regulation.
Abstract:
Background: Vincristine (VCR) is a chemotherapeutic drug commonly used in the treatment
of Colorectal Cancer (CRC). However, VCR drug resistance may result in reduced efficacy
and even failure of chemotherapy in CRC treatment. MiRNA has been demonstrated to be associated
with the sensitivity of tumor cells to chemotherapy.
Objectives: This study aimed to identify a novel miRNA-14669 that can reverse vincristine resistance
and sensitize drug-resistant colorectal cancer cells.
Methods: High-throughput sequencing was performed to screen miRNAs that are associated with
VCR drug resistance, and qRT-PCR was used for further validation. The miRNA mimic and inhibitor
were designed and transfected into HCT-8,HCT-116 and HCT-8/VCR cells. Wound healing
test examined the effect of the miRNA on the migration of colorectal cancer cells. Flow cytometry
was used to evaluate cell apoptosis of HCT-8 cells. Survivin, Bcl-2, GST3, MDR1 and MRP1 expressions
were detected by Western blot.
Results: The expression of miRNA-14669 in HCT-8/VCR cells was 1.925 times higher than that
of the HCT-8 cells. After transfecting with mimic miRNA, HCT-8 and HCT-116 cells showed an
increased survival rate. The survival rate of HCT-8/VCR cells decreased by transfection of inhibitor.
The inhibitor also sensitized HCT-8 and HCT-116 cells to VCR or 5-Fluorouracil (5-FU). The
migratory ability of HCT-8 and HCT-116 cells increased by miRNA mimic while reduced by miRNA
inhibitor. Overexpression of miRNA-14669 reduced apoptosis, while downregulation of miRNA-
14669 increased cell apoptosis in HCT-8 cells. The mechanism of the miRNA involved in
drug resistance may be attributed to apoptosis of tumor cells, detoxification of GST3 and drug efflux
induced by MDR1 and MRP1. PI3K / AKT is the signaling pathway related to drug resistance.
Conclusion: We identified a novel miRNA-14669 that may be associated with the chemotherapeutic
resistance in CRC cells.
