DNA sequencing has provided data to indicate that cancer cells may contain tens of thousands of somatic mutations, only some of which confer a growth advantage to a cancer cell. How do scientists describe and categorize these recently discovered populations of mutations in cancer cells?

Key Concepts

Somatic Mutations

Somatic mutations are genetic alterations that occur in non-germline cells, meaning they are not inherited but arise during an individual's lifetime. These mutations can result from environmental factors, errors in DNA replication, or other cellular processes. In cancer, somatic mutations can accumulate and contribute to tumorigenesis by altering cell behavior, such as promoting uncontrolled growth.

Tumor Heterogeneity

Tumor heterogeneity refers to the presence of diverse cell populations within a single tumor, which can differ genetically and phenotypically. This diversity arises from the accumulation of somatic mutations and can lead to variations in how cancer cells respond to treatment. Understanding tumor heterogeneity is crucial for developing effective therapies, as some mutations may confer resistance to specific drugs.

Oncogenic Mutations

Oncogenic mutations are specific genetic changes that promote cancer development by enhancing cell proliferation or survival. These mutations often affect genes involved in critical pathways, such as those regulating cell cycle, apoptosis, and signal transduction. Scientists categorize mutations based on their functional impact, distinguishing between driver mutations, which contribute to cancer progression, and passenger mutations, which do not affect tumor growth.