Related Experiment Video

Updated: May 8, 2026

Analysis of Combinatorial miRNA Treatments to Regulate Cell Cycle and Angiogenesis
11:44

Analysis of Combinatorial miRNA Treatments to Regulate Cell Cycle and Angiogenesis

Published on: March 30, 2019

MicroRNA-503 inhibits the G1/S transition by downregulating cyclin D3 and E2F3 in hepatocellular carcinoma

Fenqiang Xiao1, Wu Zhang, Liming Chen

  • 1Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Key Laboratory of Organ Transplantation, Zhejiang Province, Hangzhou, Zhejiang, P.R. China.

Journal of Translational Medicine
|August 24, 2013
PubMed
Abstract

Insights

MicroRNA-503 (miR-503) is frequently downregulated in hepatocellular carcinoma (HCC), acting as a tumor suppressor by inhibiting cell proliferation. Low miR-503 levels indicate poor prognosis in HCC patients, suggesting its potential as a therapeutic target.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • MicroRNAs (miRNAs) play a role in tumorigenesis, with miR-503 downregulation observed in various cancers.
  • The specific function of miR-503 in hepatocellular carcinoma (HCC) remains largely unexplored.

Purpose of the Study:

  • To investigate the prognostic significance of miR-503 in HCC.
  • To elucidate the pathophysiological role of miR-503 in HCC development and progression.

Main Methods:

  • Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) to assess miR-503 expression in HCC tissues and cell lines.
  • Western blotting and luciferase reporter assays to identify and validate miR-503 target genes.
  • In vivo and in vitro functional assays to determine the role of miR-503 in HCC cell behavior.

Main Results:

  • miR-503 expression was significantly downregulated in HCC tissues and cell lines.
  • Low miR-503 levels correlated with advanced tumor features (e.g., portal vein tumor thrombi, high TNM stage, elevated AFP) and poorer patient survival.
  • Functional studies revealed miR-503 suppresses HCC cell proliferation by inducing G1 phase arrest via the Rb-E2F pathway, identifying cyclin D3 and E2F3 as direct targets.

Conclusions:

  • miR-503 functions as a tumor suppressor in HCC by regulating cell cycle progression.
  • Downregulation of miR-503 is a prognostic marker for HCC.
  • miR-503 holds potential for use in HCC prognosis prediction and miRNA-based therapeutic strategies.

More Related Videos

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library08:40

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library

Published on: April 6, 2012

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice07:02

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice

Published on: August 23, 2019

Related Concept Videos

MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...