Related Experiment Video

Updated: Oct 4, 2026

The Soft Agar Colony Formation Assay
08:01

The Soft Agar Colony Formation Assay

Published on: October 27, 2014

Deregulated beta-catenin induces a p53- and ARF-dependent growth arrest and cooperates with Ras in transformation

A Damalas1, S Kahan, M Shtutman

  • 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel.

The EMBO Journal
|September 5, 2001
PubMed

Insights

Aberrant beta-catenin activation can cause tumors. However, its oncogenic activity is limited by the p53 pathway, which acts as a protective mechanism against cancer development.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cellular Biology

Background:

  • Aberrant activation of beta-catenin is a known driver for various tumors.
  • The p53 tumor suppressor protein plays a critical role in preventing cancer progression.

Purpose of the Study:

  • To investigate the interaction between mutant beta-catenin and the p53 tumor suppressor protein.
  • To elucidate the role of the ARF/INK4A pathway in mediating the effects of mutant beta-catenin on p53.

Main Methods:

  • Utilized mouse embryo fibroblasts (MEFs) with varying genetic backgrounds (wild-type, ARF-deficient, p53-deficient).
  • Assessed cell proliferation, senescence, and transformation in response to mutant beta-catenin expression.
  • Investigated the involvement of ARF and E2F1 in the induction of p53 by mutant beta-catenin.

Main Results:

  • Tumor-derived mutant beta-catenin induces accumulation and activation of p53, partly via ARF and E2F1.
  • In wild-type MEFs, mutant beta-catenin triggers senescence and inhibits proliferation.
  • In ARF- or p53-deficient cells, mutant beta-catenin overrides growth inhibition and cooperates with Ras in transformation.

Conclusions:

  • Concurrent activation of the p53 pathway by mutant beta-catenin acts as a tumor-suppressive mechanism.
  • Impairment of the p53 pathway (e.g., via p53 mutations or ARF loss) allows deregulated beta-catenin to promote oncogenesis.
  • This highlights the critical role of the p53 pathway in controlling the oncogenic potential of beta-catenin, particularly in early colorectal carcinogenesis.

More Related Videos

Identification of EGFR and RAS Inhibitors using Caenorhabditis elegans08:12

Identification of EGFR and RAS Inhibitors using Caenorhabditis elegans

Published on: October 5, 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.
The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
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...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
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...