Ras oncogene

Rat sarcoma (RAS) is the most frequently mutated oncogene in human cancer.

KRAS, Kirsten rat sarcoma, is the most common mutated RAS isoform and a key clonal  oncogenic driver.

KRAS, NRAS, and HRAS comprise a family of proteins that are highly similar, both structurally and functionally.

Oncogenic mutations in KRAS, NRAS, and HRAS are the most prevalent rotations in cancers.

Of the three RAS genes, KRAS is most commonly mutated in cancer with 85% of all RAS mutations, and mutations in KRAS  occur in nearly 90% of pancreatic cancers, nearly half of colon cancer, and more than 1/3 of lung adenocarcinomas.

Involved in transducing extracellular mitogenic signals.

The RAS guanibe nucleotide binding protein regulates cell survival, growth, and proliferation of cells.

RAS protein acts like a switch in a pathway that leads from a cell surface growth factor receptor to downstream pathways that activate cellular proliferation.

Most of the time, the RAS protein exists in the cell in an inactive state.

Guanosine diphosphate (GDP) bound to RAS makes it inactive and suppresses its activity.

Activation of RAS  occurs by means of binding replacing RAS bound GDP with RAS  guanosine triphosphate (GTP).

GTP bound RAS activates RAF, MEK, and ERK leading to cell division, survival, and migration.

RAS most frequently mutated oncogene in human tumors.

Oncogenic mutations in the RAS genes result in heightened activity of RAS proteins and these mutations commonly occur at codons 12, 13 (KRAS and HRAS) and 61 (NRAS).

Mutations in RAS identified in 30% of all human cancers.

Most RAS mutations are KRAS.

Other RAS mutations include NRAS and HRAS.

Mutations in any of 3RAS oncogenes KRAS, NRAS, and HRAS have been found to lead to autonomous growth in differentiation of cells driving cancer progression.

RAS mutations are associated with human cancers and are seen in about 16% of malignancies.

KRAS mutations are prevalent in common malignancies such as lung and colorectal cancer.

Is is an intracellular protein, so it is not on the cell surface and available for binding to drugs.

RAS proteins have many downstream effectors, of which RAF kinases have a major role.
The MAPK pathway, which is downstream is vital for a number of cellular processes,
including proliferation, differentiation and cellular growth. 
Mutations in the MAPK pathway are associated with malignancies.
Germ line mutations in genes  encoding components of the RAS-MAPK pathway cause developmental disorders referred to as RASopathies.
It exists in an active and an inactive state, and these two states that can be switched my GTPasevactivating proteins.

RAS gene mutations seen in up to 45% of colorectal cancers, 32% of pancreatic cancers and nearly all pancreatic cancers.

KRAS. and NRAS are closely related RAS oncogene family members and mutations in either gene at codons 12, 13, 61, 117, and 146 result in increased levels of guanosine triphosphate-bound RAS proteins.

Colorectal tumors harbor KRAS and NRAS mutations at these codons and mutations tend to be mutually exclusive suggesting functional redundancy.

HRAS the third member of the RAS family is seen infrequently in colorectal cancer.

RAS pathway mutations cancers less likely to respond to current therapies.

Regulates downstream pathways by cycling between an inactive guanosine diphosphate-bound state and an active guanosine triphosphate bound state.

Refers to rat sarcoma viral homolog.

A constituent of the MAP kinase pathway and mutations are found in approximately 20% of metastatic melanoma.

Mutations common in acute myelogenous leukemia and high grade myelodysplastic syndrome.

Proteins important in signal transduction in molecular oncology.

A member of a large superfamily of low molecular weight guanosine-5’-triphosphate (GTP) binding proteins.

Proteins that help control signaling pathways that regulate cell proliferation, survival and differentiation.

Members of the Ras family are HRAS, KRAS and NRAS.

KRAS accounts for nearly 90% of RAS mutations.

Somatic mutations in malignancies introduce amino acid substitution at 12, 13, 61 positions.

Activated mutations in RAS, (KRAS or NRAS) and KRA S mutations in Exon 2 are negative predictive biomarkers for anti-EGF for therapy.

BRAF mutations are typically exclusive of RAS mutations.

Most of the time, a RAS mutation is associated with poorer prognosis because there are fewer therapeutic options available.

Its colorectal cancer the right side is more likely to have KRAS and BRAF mutations and poor outcomes particularly in late stage disease.

Leave a Reply

Your email address will not be published. Required fields are marked *