Retinoblastoma Pathway-Altered Tumor Cell (RB Pathway-Altered Tumor Cell)

A retinoblastoma pathway-altered tumor cell is a cancer cell in which the retinoblastoma (RB) signaling pathway, a critical regulator of the cell cycle, is disrupted. This disruption typically involves mutation, deletion, or functional inactivation of key components such as RB1, CDKN2A (p16INK4a), or amplification/gain of CDK4, CDK6, or cyclin D. These alterations lead to deregulated cellular proliferation and are a hallmark of many human cancers. The functional consequence is loss of G1/S checkpoint control, unrestrained cellular proliferation, and impaired differentiation capacity. Therapeutically, these alterations can predict sensitivity or resistance to various therapies, including CDK4/6 inhibitors.

Other names

RB Pathway Deficient Tumor CellRB1-Mutated Cancer CellCDKN2A-Deleted Tumor CellpRB-Inactivated Cancer Cell

CDK4/6 inhibitors block cell cycle progression by preventing pRB phosphorylation, leading to cell cycle arrest in G1 phase.