Retinoblastoma Protein (pRb) – A Tumor Suppressor Gene/Protein
(The Importance of pRb in Cell Cycle Regulation and Cancer)
What is Retinoblastoma? What is the cause of Retinoblastoma?
Retinoblastoma or RB is a type of cancer affecting the retina of young individuals. RB occurs in the human population both spontaneously and as a heritable disorder. The genetic reason for the occurrence of RB is associated with a structural aberration of the chromosome. In human, the Rb gene is present on the chromosome 13 at the q-14 region. The loss of this region of due to deletion or mutation causes the retinoblastoma.
The condition of retinoblastoma arises only when both the copies of the Rb gene are lost. In the inherited form of the disease, one parental chromosome carries an alteration in this region. A spontaneous mutation in the retinal cells which results in the inactivation of the other copy of Rb gene can cause the tumor development. Thus, the loss of function of Rb protein due to mutation or deletion is the cause of retinoblastoma.
How Rb acts as a tumor suppressor gene?
A tumor suppressor gene is a gene that prevents the development of cancer. When this gene is mutated and its function is lost forever, there is a very high chance of the cell to enter into a cancerous growth.