Related Experiment Video

Updated: May 14, 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

Downregulation of the microRNA biogenesis components and its association with poor prognosis in hepatocellular

Noriyuki Kitagawa1, Hidenori Ojima, Takuya Shirakihara

  • 1Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo, Japan.

Cancer Science
|February 13, 2013
PubMed

Insights

Deregulation of microRNA (miRNA) biogenesis genes is common in non-viral hepatocellular carcinoma (HCC). Reduced expression of these genes correlates with risk factors, multicentric tumors, and poor HCC prognosis, suggesting epigenetic links.

Area of Science:

  • Oncology
  • Molecular Biology
  • Epigenetics

Background:

  • Genetic alterations in miRNA biogenesis are implicated in human cancers.
  • Dicer gene deletion promotes carcinogenesis in animal models, highlighting miRNA's role in cancer.
  • Aberrant miRNA biogenesis components are linked to cancer development.

Purpose of the Study:

  • To investigate the expression of miRNA biogenesis pathway genes in hepatocellular carcinoma (HCC).
  • To correlate gene expression with HCC subtypes, risk factors, tumor characteristics, and patient prognosis.
  • To explore the role of epigenetic regulation in miRNA biogenesis gene deregulation in HCC.

Main Methods:

  • Quantitative RT-PCR was used to analyze the expression of 14 miRNA biogenesis genes.
  • 47 paired samples of primary HCC and matched non-cancerous liver tissue were analyzed.
  • Histone modification analysis (H3K27 trimethylation) was performed on HCC cell lines.

Main Results:

  • Seven miRNA biogenesis genes showed decreased expression in HCC, particularly in non-viral HCC.
  • Reduced expression correlated with risk factors (smoking, alcohol, diabetes), multicentric tumors, and poor prognosis (Dicer, p68).
  • Epigenetic regulation via histone H3 lysine 27 trimethylation was implicated in gene deregulation in non-HBV HCC cell lines.

Conclusions:

  • Deregulation of miRNA biogenesis pathway components is frequent in non-viral HCC.
  • This deregulation is associated with etiological risk factors and predicts a poor prognosis.
  • Epigenetic mechanisms, such as histone modifications, contribute to miRNA biogenesis gene deregulation during hepatocarcinogenesis.

More Related Videos

An In Vitro Protocol for Evaluating MicroRNA Levels, Functions, and Associated Target Genes in Tumor Cells09:45

An In Vitro Protocol for Evaluating MicroRNA Levels, Functions, and Associated Target Genes in Tumor Cells

Published on: May 21, 2019

MicroRNA Detection in Prostate Tumors by Quantitative Real-time PCR (qPCR)08:30

MicroRNA Detection in Prostate Tumors by Quantitative Real-time PCR (qPCR)

Published on: May 16, 2012

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...
Experimental RNAi02:15

Experimental RNAi

RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing its transcription or activating the RNA degradation process. The mechanism was discovered by Andrew Fire and Craig Mello in 1998 in plants. Today, it is observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals. This precise cellular mechanism of gene silencing has been developed into a technique that provides an efficient way to identify and determine the...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...