Related Experiment Video

Updated: Jun 22, 2026

An Adipocyte Cell Culture Model to Study the Impact of Protein and Micro-RNA Modulation on Adipocyte Function
09:20

An Adipocyte Cell Culture Model to Study the Impact of Protein and Micro-RNA Modulation on Adipocyte Function

Published on: May 4, 2021

Growth inhibition by microRNAs that target the insulin receptor substrate-1

Gaspare La Rocca1, Bin Shi, Margherita Badin

  • 1Department of Cancer Biology at Thomas Jefferson University, Kimmel Cancer Center, Philadelphia, PA 19107, USA.

Cell Cycle (Georgetown, Tex.)
|June 9, 2009
PubMed

Insights

MicroRNAs (miRs) can induce cell death by targeting the insulin-like growth factor-1 receptor (IGF-IR) pathway. miR145 primarily functions as a tumor suppressor by downregulating insulin receptor substrate-1 (IRS-1).

Area of Science:

  • Molecular Biology
  • Oncology
  • Gene Regulation

Background:

  • The insulin-like growth factor-1 receptor (IGF-IR) signaling pathway is crucial in cell growth and survival.
  • MicroRNAs (miRs) are key regulators of gene expression involved in various cellular processes, including cancer.

Purpose of the Study:

  • To investigate the role of specific microRNAs (miRs) in targeting the IGF-IR signaling pathway.
  • To identify the predominant target of miR145 responsible for its tumor suppressor activity.

Main Methods:

  • Bioinformatic analysis to identify miRs targeting the IGF-IR pathway.
  • Experimental validation of miR targets and their functional consequences on cell death.

Main Results:

  • Several miRs were identified as targeting the IGF-IR pathway, with most exhibiting multiple targets.
  • miR145 demonstrated significant tumor suppressor activity primarily through the downregulation of insulin receptor substrate-1 (IRS-1), a key docking protein for IGF-IR.

Conclusions:

  • While database predictions often indicate multiple targets for miRs, a single predominant target can significantly influence the outcome.
  • miR145's specific targeting of IRS-1 is critical for its tumor suppressor function in the context of IGF-IR signaling.

More Related Videos

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

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

Related Concept Videos

PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Insulin: The Receptor and Signaling Pathways01:28

Insulin: The Receptor and Signaling Pathways

Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
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...
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...
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...