Identify the normal functions of the following genes whose mutations are associated with the development of cancer.

RB1 (retinoblastoma)

Key Concepts

Tumor Suppressor Genes

Tumor suppressor genes are crucial for regulating cell growth and preventing uncontrolled cell division. They produce proteins that help control the cell cycle, repair DNA, and promote apoptosis (programmed cell death). When these genes are mutated, their function is lost, leading to increased risk of cancer, as seen with the RB1 gene in retinoblastoma.

RB1 Gene Function

The RB1 gene encodes the retinoblastoma protein (pRB), which plays a key role in regulating the cell cycle by inhibiting progression from the G1 phase to the S phase. pRB binds to and inactivates transcription factors that promote cell division. Mutations in RB1 disrupt this regulation, leading to unrestrained cell proliferation and the development of tumors, particularly in the retina.

Cancer Development Mechanisms

Cancer development often involves a series of genetic mutations that lead to the dysregulation of normal cellular processes. These mutations can affect oncogenes, which promote cell growth, or tumor suppressor genes, which inhibit it. Understanding the balance between these opposing forces is essential for comprehending how mutations in genes like RB1 contribute to cancer, as they tip the scales towards uncontrolled growth.