Related Experiment Video
Updated: Nov 23, 2025

Defining Gene Functions in Tumorigenesis by Ex vivo Ablation of Floxed Alleles in Malignant Peripheral Nerve Sheath Tumor Cells
Published on: August 25, 2021
Tumor Suppressors Having Oncogenic Functions: The Double Agents
Neerajana Datta1, Shrabastee Chakraborty1, Malini Basu2
1Cancer Biology and Inflammatory Disorder Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology (CSIR-IICB), TRUE Campus, CN-6, Sector-V, Salt Lake, Kolkata-700091 & 4, Raja S.C. Mullick Road, Jadavpur, Kolkata-700032, India.
Some tumor suppressor genes act as double agents in cancer, promoting proliferation through mechanisms like haploinsufficiency or epigenetic changes. This review examines how pRb, PTEN, FOXO, and PML exhibit oncogenic potential in cancer progression.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Genetics
Background:
- Cancer progression involves oncogene activation and tumor suppressor gene inactivation.
- Traditionally, tumor suppressor genes are recessive and anti-proliferative.
- Recent findings reveal some tumor suppressors act as 'double agents' with dual roles.
Purpose of the Study:
- To review exceptions to the classical tumor suppressor gene definition.
- To highlight how specific tumor suppressors can promote cancer.
- To explore the mechanisms behind these dual roles in cancer pathogenesis.
Main Methods:
- Literature review of genetic and epigenetic events in cancer.
- Analysis of cellular contexts and mechanisms of tumor suppressor gene function.
- Focus on four key tumor suppressors: pRb, PTEN, FOXO, and PML.
Main Results:
- Certain tumor suppressor genes can exhibit oncogenic potential.
- Mechanisms include haploinsufficiency, epigenetic hypermethylation, and interaction with oncogenic events.
- pRb, PTEN, FOXO, and PML can display pro-proliferative and pro-survival traits in cancer.
Conclusions:
- The role of tumor suppressor genes in cancer is more complex than previously thought.
- Understanding these 'double agent' functions is crucial for cancer therapy.
- Further research into these exceptions can reveal new therapeutic targets.
Related Concept Videos
Loss of Tumor Suppressor Gene Functions
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
Cancer-Critical Genes II: Tumor Suppressor Genes
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...
Cancer-Critical Genes I: Proto-oncogenes
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...
Abnormal Proliferation
The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Cancer

