MEBGEN™ RASKET KIT RAS mutation detection kit
RAS gene mutation in colon cancer
The RAS gene was identified as a retroviral oncogene inducing sarcomas. To date, three kinds of RAS genes (i.e., KRAS, NRAS, and HRAS) have been reported as human oncogenes. The proteins coded by such genes are usually in GDP (Guanosine diphosphate)-bound inactive form. In response to a signal transduction, GDP dissociates and RAS proteins are converted to GTP (Guanosine triphophate)-bound active form allowing interaction with factors such as RAF.
Once a mutation occurs in RAS genes, RAS proteins are constitutively activated to induce signals and can be no longer suppressed by anti-EGFR antibodies. This is the main mechanism of resistance to anti-EGFR therapy in colorectal patients with RAS mutation.
In colorectal cancer, KRAS mutations occur at a frequency of about 35-40%, while NRAS mutations show a frequency of about 3-4%. HRAS mutations have a much lower frequency in colorectal cancer and observed in less than 1% of patients.
Frequency of mutation in codons of RAS genes in colorectal cancer
Analyzed from the Cancer Genome Atlas (TCGA) database