Abstract
Chromosome 6 is among the 23 pairs of chromosomes in humans and it spans about 170 million base pairs. Several cancer genes have been identified to have a role in cancer development. Cancer is also a genetic disease caused due to changes in the genes that control cell function, such as cell division and cell growth. Most of these cancer genes either act as tumor suppressors or possess an oncogenic potential. Oncogenes like ROS1, MYB, HMGA1, etc., induce tumorigenesis by playing a role in DNA repair, replication, transcriptional regulation, and mRNA splicing. When these genes are highly expressed, they result in the transformation of normal cells to malignant cells; on the other side, tumor suppressor genes like IGF2R, AIM1, IRF4, etc., reduce tumorigenicity and invasive potential. Thus, reduced expression of these genes due to loss of heterozygosity, deletion or any epigenetic modifications can induce tumor formation. Also, some genes can either suppress or induce tumor formation given the cellular location and condition, such as CCN2, TNF, etc. Along with these, different types of structural abnormalities can be observed on chromosome 6, such as chromosomal translocation, deletion, duplication, and inversion. These abnormalities on both p and q arms have been known to contribute to the growth and spread of cancer by impacting the expression of cancer genes. Aberrant expression of the genes can also be influenced by fusions, missense mutations, non-missense mutations, silent mutations, frame-shift deletions, and insertion at the molecular level. Some genes can maintain stem-cell-like properties by regulating the expression of cell surface markers like Oct4, Nanog, Sox4, etc. This chapter explains important cancer genes, genetic mutations, and gene variations that can influence the risk of having cancer and induces cancer formation.