oncogeeneissä

Oncogenes are genes that have the potential to cause cancer. They are derived from a class of normal genes called proto-oncogenes, which play important roles in cell growth, division, and differentiation. Proto-oncogenes can become oncogenes through mutations, chromosomal translocations, or viral insertions. These alterations can lead to the overproduction of proteins that promote cell proliferation or inhibit cell death, ultimately contributing to the development of cancer.

Proto-oncogenes function by encoding proteins that regulate the cell cycle, such as growth factors, receptors, signaling molecules, and transcription factors. When a proto-oncogene mutates into an oncogene, it can become constitutively active or overexpressed, leading to uncontrolled cell growth. For example, mutations in the RAS gene family can lead to constant signaling for cell division, even in the absence of external growth signals. Similarly, mutations in the MYC gene can result in overexpression, promoting cell proliferation.

The activation of oncogenes is a critical step in the multi-step process of carcinogenesis. While oncogene activation drives uncontrolled cell growth, cancer development typically requires the inactivation of tumor suppressor genes, which normally act to inhibit cell proliferation and repair DNA damage. The interplay between activated oncogenes and inactivated tumor suppressor genes creates an environment conducive to tumor formation and progression. Understanding oncogenes is crucial for developing targeted cancer therapies that aim to inhibit the function of these cancer-promoting genes.