Question

What is the relationship between proto-oncogenes and oncogenes?

Answer 1

Proto-oncogenes are positive cell-cycle regulators. When mutated, they can become oncogenes and cause cancer. For example, the oncogene myc is involved in Burkett's Lymphoma.

Step-by-step explanation:

Proto-oncogenes are positive cell-cycle regulators. When mutated, proto-oncogenes can become oncogenes and cause cancer. Overexpression of the oncogene can lead to uncontrolled cell growth. This is because oncogenes can alter transcriptional activity, stability, or protein translation of another gene that directly or indirectly controls cell growth. An example of an oncogene involved in cancer is a protein called myc. Myc is a transcription factor that is aberrantly activated in Burkett's Lymphoma, a cancer of the lymph system. Overexpression of myc transforms normal B cells into cancerous cells that continue to grow uncontrollably. High B-cell numbers can result in tumors that can interfere with normal bodily function. Patients with Burkett's lymphoma can develop tumors on their jaw or in their mouth that interfere with the ability to eat.

Answer 2

Oncogenes result from a mutation in proto-oncogenes.

Step-by-step explanation:

• Protooncogenes control the growth and division of cells.
• The proteins encoded by proto-oncogenes include growth factors, growth factor receptors, transcription factors and signal transducers.
• They contribute to the transformation process by driving cell proliferation or reducing sensitivity to cell death.
• Several types of genetic and epigenetic changes convert these proto-oncogenes to oncogenes.
• Oncogenes arise due to the changes that increases the expression of proto-oncogenes .
• Oncogenes are one of the causes of cancers.

A proto-oncogenes can turn into oncogene by following ways:

• A point mutation such as deletion, insertion and substitution in the proto-oncogene can lead to formation of oncogenes.
• Chromosomal translocation may result in activation of proto-oncogene as seen in Burkitt's lymphoma.
• Insertion of a mobile genetic material such as retrovirus changes the gene expression, but leaves their coding sequence intact.
• Activation of proto-oncogene can also occur from reduplication and amplification of DNA sequence.