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In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
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In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice

Published on: August 23, 2019

Tumor suppressor functions of miR-133a in colorectal cancer

Yujuan Dong1, Junhong Zhao, Chung-Wah Wu

  • 1Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong. junyu@cuhk.edu.hk.

Molecular Cancer Research : MCR
|June 1, 2013
PubMed
Abstract

Insights

MicroRNA 133a (miR-133a) acts as a tumor suppressor in colorectal cancer by inhibiting cell growth and sensitizing cells to chemotherapy. Its downregulation in tumors suggests a role in cancer development.

Area of Science:

  • Molecular Biology
  • Oncology
  • Genetics

Background:

  • MicroRNA (miRNA) expression is often dysregulated in human cancers, including colorectal cancer (CRC).
  • Specific miRNAs may play critical roles in tumor suppression or progression.
  • Understanding miRNA roles is crucial for developing novel cancer therapies.

Purpose of the Study:

  • To investigate the role of miR-133a in colorectal cancer development and progression.
  • To elucidate the molecular mechanisms underlying miR-133a's function in CRC.
  • To evaluate miR-133a's potential as a therapeutic target in CRC.

Main Methods:

  • miRNA array profiling of colorectal cancer tissues versus adjacent normal tissues.
  • Laser capture micro-dissection to isolate tumor cells.
  • In vitro and in vivo cell growth assays, cell-cycle analysis, Western blotting, luciferase reporter assays, and drug sensitivity testing.

Main Results:

  • miR-133a was significantly downregulated in colorectal cancer tissues.
  • Ectopic miR-133a expression suppressed colorectal cancer cell growth by inducing G0/G1-phase arrest via p53/p21(Cip1) pathway.
  • miR-133a directly targets RFFL (E3-ubiquitin ligase) mRNA, inhibiting its translation and increasing p53 levels.
  • miR-133a sensitized colon cancer cells to doxorubicin and oxaliplatin by enhancing apoptosis and inhibiting proliferation.

Conclusions:

  • miR-133a functions as a tumor suppressor in colorectal cancer, acting upstream of the p53 pathway.
  • Downregulation of miR-133a contributes to colorectal cancer development.
  • miR-133a holds potential for sensitizing colorectal cancer cells to chemotherapeutic agents.

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