Related Experiment Video

Updated: Aug 8, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Transforming growth factor-beta inhibits rat intestinal cell growth by regulating cell cycle specific gene expression

T C Ko1, R D Beauchamp, C M Townsend

  • 1Department of Surgery, University of Texas Medical Branch Galveston 77555-0533.

American Journal of Surgery
|January 1, 1994
PubMed

Insights

Transforming growth factor-beta 1 (TGF-beta 1) inhibits intestinal cell growth by blocking cell cycle progression at the G1 phase. This occurs by suppressing cdc2 gene induction, not immediate early gene activation.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Gastroenterology

Background:

  • Transforming growth factor-beta 1 (TGF-beta 1) is known to inhibit intestinal cell growth.
  • The precise mechanisms and cell cycle stage targeted by TGF-beta 1 remain unclear.

Purpose of the Study:

  • To identify the specific cell cycle phase where TGF-beta 1 inhibits intestinal crypt cell proliferation.
  • To investigate the impact of TGF-beta 1 on the expression of key cell cycle regulatory genes.

Main Methods:

  • Utilized a rat intestinal crypt cell line (IEC-6).
  • Assessed cell cycle progression via 3H-thymidine incorporation.
  • Analyzed gene expression of immediate early genes (zif268, jun-B, c-myc) and cdc2 using Northern blot analysis.

Main Results:

  • TGF-beta 1 blocks rat intestinal crypt cell proliferation at the middle G1 phase.
  • Immediate early genes (zif268, jun-B, c-myc) remain TGF-beta 1 insensitive during early G1.
  • TGF-beta 1 sensitive cdc2 gene induction is suppressed during the G1 to S phase transition.

Conclusions:

  • TGF-beta 1 inhibits intestinal cell proliferation by specifically targeting the G1/S transition.
  • The mechanism involves the suppression of cdc2 gene expression, while early G1 gene activation is unaffected.

More Related Videos

Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-β Signaling07:49

Molecular Analysis of Endothelial-mesenchymal Transition Induced by Transforming Growth Factor-β Signaling

Published on: August 3, 2018

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells06:54

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells

Published on: October 27, 2020

Related Concept Videos

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...
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...
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
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...
Role Of Notch Signalling In Intestinal Stem Cell Renewal01:12

Role Of Notch Signalling In Intestinal Stem Cell Renewal

Notch signaling was first discovered in Drosophila melanogaster, where it is involved in cell lineage differentiation. Notch signaling regulates the maintenance and differentiation of intestinal stem cells or ISCs by controlling the expression of atonal homolog 1 or Atoh1. Atoh1 directs cells to differentiate into secretory cells.
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...