Related Experiment Video

Updated: Jun 25, 2026

Genome-wide Screen for miRNA Targets Using the MISSION Target ID Library
08:40

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

Published on: April 6, 2012

MicroRNA-21 regulates the proliferation and invasion in esophageal squamous cell carcinoma

Yukiharu Hiyoshi1, Hidenobu Kamohara, Ryuichi Karashima

  • 1Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|March 12, 2009
PubMed
Abstract

Insights

MicroRNA-21 is overexpressed in esophageal squamous cell carcinoma, promoting cancer cell proliferation and invasion. Targeting microRNA-21 may offer a new therapeutic strategy for this disease.

Area of Science:

  • Molecular Biology
  • Oncology
  • Gene Regulation

Background:

  • MicroRNAs are key regulators of gene expression.
  • Esophageal squamous cell carcinoma (ESCC) is a significant global health concern.
  • Understanding molecular mechanisms driving ESCC is crucial for developing targeted therapies.

Purpose of the Study:

  • To investigate the role of microRNA-21 (miR-21) in ESCC.
  • To determine if miR-21 regulates the programmed cell death 4 (PDCD4) gene.
  • To explore miR-21 as a potential therapeutic target in ESCC.

Main Methods:

  • Quantitative real-time PCR and in situ hybridization were used to assess miR-21 expression in ESCC tissues and cell lines.
  • Cell proliferation and invasion assays were performed using anti-miR-21-transfected cells.
  • Western blotting and luciferase reporter assays were employed to elucidate the regulatory mechanism of PDCD4 by miR-21.

Main Results:

  • miR-21 was significantly overexpressed in 18 of 20 ESCC tissues compared to normal samples.
  • High miR-21 expression correlated with lymph node metastasis and venous invasion.
  • Inhibition of miR-21 reduced ESCC cell proliferation and invasion, and increased PDCD4 protein levels, suggesting posttranscriptional regulation.

Conclusions:

  • miR-21 directly targets PDCD4 at the posttranscriptional level.
  • miR-21 plays a critical role in regulating cell proliferation and invasion in ESCC.
  • miR-21 represents a promising therapeutic target for ESCC treatment.

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...
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...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...