Mutations of RAS gene
family in specimens of bladder cancer.
In human, there are 3 ubiquitously expressed RAS genes
, KRAS, NRAS, and HRAS, which encode four highly homologous RAS proteins (splicing variants KRAS4A/4B, NRAS, and HRAs).
However, recent reports showed that the RAS genes
mutations are present in only 1-13% of bladder cancer and less frequent in muscle-invasive cancer [19-21].
Mutations in ras gene
result in oncogenic activation and pathogenesis of various cancer including lung pancreatic and colorectal carcinoma and OSCC.28).
Barbacid, "ras genes
," Annual Review of Biochemistry, vol.
Evidence for ras gene
mutation in 2-amino-3-methylimidazo [4,5-f]quinoline-induced colonic aberrant crypts in the rat.
The RAS gene
is known to encode for a family of related proteins, termed p21s, which are associated with the plasma membrane and participate in the transduction of signals involved in cellular growth and differentiation.
It is thought that adenomas incur a mutation of the ras gene
leading to their evolution into "intermediate" adenomas.
Mutations that make one of these, the Ras gene
, hyperactive prompt cells to proliferate wildly.
Applying techniques of molecular biology the researchers sequence each patient's abnormal RAS gene
to identify the specific mutation.
Activating mutations in one of the three human RAS gene
isoforms (KRAS, HRAS, or NRAS) are present in about one-quarter of all cancers.
Specificity (Inclusivity and Exclusivity).--The RAS gene
family includes 3 genes with high homology to KRAS: HRAS, NRAS, and a pseudogene (KRASP1).