Name: tumor suppressor genes and cancer risk
Uploaded: 2021-04-07T12:12:02.000Z
Duration: 1 min 12 s
Channel: JoVE

In a healthy cell, tumor suppressor genes act as the gatekeepers that control cell growth and proliferation and promote cell apoptosis.
Hence, when a tumor suppressor gene is inactivated, cells may start growing out of control leading to cancer.
Fortunately, in most cases, the inactivation of a single allele of a tumor suppressor gene does not lead to tumor progression. Both of the alleles must lose their function for the cells to become cancerous.
Such loss of function mutations in tumor suppressor genes can be caused by genetic alterations such as point mutations,&#160; chromosomal deletion,&#160; or errors in chromosome segregation.
However, a few epigenetic changes can also permanently inactivate the tumor suppressor genes. For example, if a gene undergoes modifications in its promoter region or gets packaged into the heterochromatin region of a chromosome, it can make irreversible and heritable changes to the gene expression pattern.

loss of tumor suppressor gene functions

Loss of Tumor Suppressor Gene Functions

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
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 cycle. It&#39;s only when both the copies of the gene are inactivated or lost that the cells lose control and become cancerous.
Some common tumor suppressor genes that have implications in human cancer include TP53, Rb, INK4, PTEN, APC, BRCA1/BRCA2, and MADR2. Loss of function mutations in these tumor suppressor genes has implications in many types of cancers, including ovarian, lung, colorectal, head and neck, pancreatic, uterine, breast, and bladder cancer.

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable ...

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JoVE Core

Molecular Biology

Unit 2

Cancer

KEY TERMS AND CONCEPTS

tumor suppressor genes and cancer risk

Tumor suppressor genes help protect cells from becoming cancerous. They can slow cell division, repair DNA mistakes, or trigger apoptosis, which is programmed cell death, when damage cannot be fixed. These jobs help stop damaged cells from multiplying.

When a tumor suppressor gene mutates or is lost, cells may begin to grow out of control. A single working copy is usually enough for the cell to keep normal control of the cell cycle. Cancer develops when both copies are inactivated or lost.

Several tumor suppressor genes are linked to human cancer. These include TP53, Rb, INK4, PTEN, APC, BRCA1, BRCA2, and MADR2. Loss of function in these genes has been associated with ovarian, lung, colorectal, head and neck, pancreatic, uterine, breast, and bladder cancer.

Tumor Suppressor Genes and Cancer Risk

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Tumor suppressor genes help protect cells from becoming cancerous. They can slow cell division, repair DNA mistakes, or trigger apoptosis, which is programmed cell death, when damage cannot be fixed. These jobs help stop damaged cells from multiplying. When a tumor suppressor gene mutates or is lost, cells may begin to grow out of control. A single working copy is usually enough for the cell to keep normal control of the cell cycle. Cancer develops when both copies are inactivated or lost. <br...

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key terms and concepts

Learn how tumor suppressor genes help control cell growth, repair DNA, and prevent cancer when both gene copies are lost or inactivated.

Tumor Suppressor Genes and Cancer Risk | JoVE K12

molecular biology

JoVE Core Molecular Biology showcases the molecular processes of the cell through clear and concise animated video lessons. Additionally, in scientist-in-action videos, these concepts' application is demonstrated through real experiments in modern laboratories.

Tumor Suppressor Genes and Cancer Risk

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