Title:MiR-125b Inhibits Cell Proliferation and Induces Apoptosis in Human
Colon Cancer SW480 Cells via Targeting STAT3
Volume: 17
Issue: 2
Author(s): Junhe Zhang*, Wenwen Yang, Yunxi Xiao and Linlin Shan
Affiliation:
- Department of Biochemistry and Molecular Biology, Xinxiang Medical University, Xinxiang 453003, Henan, P.R.
China
- Institutes
of Health Central Plains, Xinxiang Medical University, Xinxiang, 453003, Henan, P.R. China
Keywords:
Apoptosis, Bcl-2, colon cancer, miR-125b, proliferation, STAT3.
Abstract:
Background: Colon cancer is one of the most common types of cancer worldwide. Multiple
studies have unveiled the key role of microRNAs (miRNAs) in the development of various
types of cancer. However, the mechanism of action of miR-125b in the development and progression
of colon cancer remains unknown.
Objectives: In this study, we explored the association of miR-125b and signal transducer and activator
of transcription 3 (STAT3) and its role in the proliferation and apoptosis of SW480 colon cancer
cells.
Methods: The miR-125b expression in NCM460, SW480, HT29, and HCT8 cells was detected using
quantitative real-time polymerase chain reaction (qRT-PCR). SW480 cells were transfected
with lentiviruses of GFP-miR-125b and GFP-NC to establish a stable miR-125b overexpression
colon cancer cell model and a control model. The targeting relationship between miR-125b and
STAT3 was analyzed using bioinformatics and verified by the dual-luciferase reporter gene assay.
Cell proliferation and apoptosis were assessed using the Cell Counting Kit-8 assay and TUNEL
staining. The expression levels of STAT3, Bcl-2, and Bax were analyzed using Western blot analysis.
Results: It was found that the relative mRNA expression of miR-125b was decreased in SW480,
HT29, and HCT8 cells compared with that in NCM460 cells (P<0.05). The luciferase reporter gene
assay confirmed that miR-125b downregulated the STAT3 gene expression (P<0.05). Overexpression
of miR-125b inhibited proliferation and promoted apoptosis in SW480 colon cancer cells and
was accompanied by upregulated Bax expression and downregulated Bcl-2 expression (P<0.05).
Re-expression of STAT3 promoted cell proliferation and inhibited cell apoptosis, whereas Bcl-2 expression
increased, and Bax expression decreased (P<0.05).
Conclusion: The miR-125b regulates the expression of Bax and Bcl-2 by downregulating the expression
of STAT3, thereby inhibiting proliferation and inducing apoptosis of SW480 colon cancer
cells.