Related Experiment Video
Updated: Aug 15, 2026
14:57
Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Evidence for selective expression of the p53 codon 72 polymorphs: implications in cancer development
Mobin M Siddique1, Chowbay Balram, Lucja Fiszer-Maliszewska
1Laboratory of Molecular Carcinogenesis, National Cancer Centre, Singapore.
Summary
The p53 gene
Area of Science:
- Genetics
- Molecular Biology
- Cancer Research
Background:
- The p53 tumor suppressor protein plays a crucial role in preventing cancer.
- Polymorphism at codon 72 of the p53 gene results in arginine (arg) or proline (pro) variants, with debated functional implications in carcinogenesis.
- Ethnic variations in p53 polymorphism expression and their association with cancer susceptibility are not fully understood.
Purpose of the Study:
- To investigate the selective regulation of p53 arginine/proline (arg/pro) polymorph expression in different ethnic populations.
- To determine if p53 polymorph expression differs between healthy individuals and breast cancer patients of Asian and Caucasian descent.
- To explore the potential of p53 polymorph expression status as an indicator of cancer susceptibility.
Main Methods:
- Analysis of p53 gene expression using mRNA from peripheral blood of healthy Chinese (Asian) and Polish (Caucasian) subjects heterozygous for the arg/pro polymorphism.
- Comparison of p53 polymorph expression in healthy individuals versus heterozygote Chinese breast cancer patients.
- Examination of p53 polymorph expression in histologically normal tissues from Chinese breast cancer patients.
Main Results:
- Healthy Asians preferentially expressed the p53 proline (pro) allele, while healthy Caucasians preferentially expressed the arginine (arg) allele.
- Approximately 75% of Chinese breast cancer patients (heterozygotes) preferentially expressed the arg allele, which rarely had somatic mutations.
- Histologically normal tissues from Chinese breast cancer patients showed selective arg allele expression, contrasting with the preferential pro allele expression in healthy Chinese breast tissues.
Conclusions:
- p53 polymorph expression is selectively regulated and varies significantly between different ethnic groups.
- The arginine allele of p53 appears to be activated during breast cancer development in Asian populations.
- The expression status of p53 polymorphs, not just the genotype, may serve as a valuable biomarker for cancer susceptibility.
Related Concept Videos
02:23Abnormal 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...
02:36DNA 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...
02:36DNA 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...
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:33Cancer-Critical Genes I: Proto-oncogenes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:23Negative 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.