What chromosomes are affected by colon cancer?
Colorectal cancer is frequently caused by abnormal changes in multiple genes. Some well-known gene alterations that contribute to the development of colorectal cancer are:
1. APC (Adenomatous Polyposis Coli) gene: Mutations in the APC gene are frequently seen in familial adenomatous polyposis (FAP) and account for about 1% of all colorectal cancer cases. The APC gene acts as a tumor suppressor, regulating cell growth and proliferation. Mutations in this gene lead to the formation of multiple polyps in the colon and rectum, increasing the risk of developing colorectal cancer.
2. KRAS (Kirsten Rat Sarcoma Viral Oncogene Homolog) gene: KRAS mutations are present in approximately 20-40% of sporadic colorectal cancers. The KRAS gene encodes a protein involved in cell signaling pathways that control cell growth and differentiation. Mutations in KRAS can lead to uncontrolled cell growth and division, contributing to the formation of tumors.
3. TP53 (Tumor Protein p53) gene: TP53 mutations occur in around 50-60% of colorectal cancers. The TP53 gene acts as a tumor suppressor, playing a crucial role in DNA repair, cell cycle regulation, and apoptosis (programmed cell death). Mutations in TP53 impair these cellular processes, allowing damaged cells to survive and potentially develop into cancer.
4. BRAF (B-Raf Proto-Oncogene, Serine/Threonine Kinase) gene: BRAF mutations are found in approximately 10% of colorectal cancers. The BRAF gene encodes a protein involved in the MAPK signaling pathway, which regulates cellular growth, proliferation, and differentiation. Mutations in BRAF can lead to the overactivation of this pathway, resulting in uncontrolled cell growth and tumor development.
5. PIK3CA (Phosphoinositide-3-Kinase, Catalytic Subunit Alpha) gene: PIK3CA mutations are present in about 15-20% of colorectal cancers. The PIK3CA gene encodes a protein involved in the PI3K signaling pathway, which regulates cellular functions such as growth, proliferation, and metabolism. Mutations in PIK3CA can lead to the overactivation of this pathway, contributing to tumorigenesis.
It's important to note that while these genetic alterations are commonly associated with colorectal cancer, not all cases are caused by them. Other genetic factors, inherited genetic mutations, and environmental factors also play roles in the development of this disease.