Related Experiment Video

Updated: Oct 13, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

The growth-inhibitory function of p53 is separable from transactivation, apoptosis and suppression of transformation

R S Hansen1, A W Braithwaite

  • 1Division of Immunology and Cell Biology, John Curtin School of Medical Research, Australian National University, Canberra, Australia.

Oncogene
|September 5, 1996
PubMed

Insights

The tumor suppressor protein p53 has distinct functions, including apoptosis induction and cell growth inhibition. This study reveals that p53

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Biology

Background:

  • The p53 protein is a critical tumor suppressor involved in multiple cellular processes.
  • Key functions of p53 include suppressing oncogenic transformation, inhibiting cell growth, inducing apoptosis, and regulating gene transcription.
  • Understanding the interplay between these p53 functions is crucial for elucidating its tumor suppressor mechanisms.

Purpose of the Study:

  • To investigate the relationships between the distinct functions of p53, including cell growth inhibition, apoptosis induction, and transcriptional regulation.
  • To determine whether specific p53 activities are prerequisites for others.
  • To elucidate the cellular and biochemical mechanisms underlying p53's tumor suppressor functions.

Main Methods:

  • Examination of various mutant forms of p53.
  • Assessing the abilities of these mutants to perform specific p53 activities: oncogenic transformation suppression, cell growth inhibition, apoptosis induction, and gene transcription activation/repression.
  • Correlation analysis of different p53 functions.

Main Results:

  • p53's ability to inhibit cell growth is separate from its ability to induce apoptosis; growth inhibition is not a prerequisite for apoptosis.
  • Suppression of oncogenic transformation by p53 correlates with its apoptosis-inducing capacity, not its growth-inhibitory function.
  • Transcriptional activation and repression by p53 are neither sufficient nor necessary for growth inhibition, suggesting alternative growth-inhibitory mechanisms.
  • Transcriptional activation and repression may be necessary, and their combination sufficient, for p53-dependent apoptosis.

Conclusions:

  • p53 possesses distinct and alternative mechanisms for inducing apoptosis and inhibiting cell growth.
  • The tumor suppressive role of p53 in transformation is primarily linked to its apoptotic function.
  • p53 utilizes multiple biochemical pathways for growth inhibition and apoptosis, highlighting its complex regulatory role in tumor suppression.

More Related Videos

Yeast As a Chassis for Developing Functional Assays to Study Human P5314:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence04:56

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence

Published on: December 30, 2025

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.
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
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...
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...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
DNA Damage Can Stall the Cell Cycle02:36

DNA Damage Can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...