In this chapter, we focused on cancer as a genetic disease, with an emphasis on the relationship between cancer, the cell cycle, and DNA damage, as well as on the multiple steps that lead to cancer. At the same time, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter,

How do we know that cancer development requires more than one mutation?

Key Concepts

Multistep Carcinogenesis

Multistep carcinogenesis is the process by which cancer develops through a series of genetic mutations over time. This concept emphasizes that cancer is not caused by a single mutation but rather by the accumulation of multiple mutations in key genes that regulate cell growth and division, leading to uncontrolled cell proliferation.

Oncogenes and Tumor Suppressor Genes

Oncogenes and tumor suppressor genes are critical components in the regulation of the cell cycle. Oncogenes promote cell division and growth, while tumor suppressor genes inhibit these processes. Mutations in these genes can disrupt their normal functions, contributing to the development of cancer, which typically requires alterations in both types of genes.

DNA Damage and Repair Mechanisms

DNA damage can occur due to various factors, including environmental influences and replication errors. Cells have repair mechanisms to fix this damage, but if these mechanisms fail or are overwhelmed, mutations can accumulate. The relationship between DNA damage and cancer underscores the importance of multiple mutations in the progression of the disease, as it often takes several failures in repair processes to lead to cancerous growth.