In this study, the relationship between BRAF mutation and apoptosis is not so clear, but BRAF mutations and inhibition in apoptosis may play an important role in the developmental process of flat and depressed early colorectal cancer.
BRAFV600E mutation was analyzed in CRC patients with MMR deficiencies (microsatellite instability and/or lack of MLH1/MSH2 protein expression) in the EPICOLON population-based study.
With at least 3 markers methylated, new CIMP-positive colorectal cancers (16.9%) were closely associated with proximal tumor location, low frequency of KRAS mutation, and high frequency of BRAF mutation (all P values were less than .05), whereas classic CIMP-positive colorectal cancers (18.5%) were closely associated with proximal tumor location, frequent microsatellite instability, and frequent BRAF mutation (all P values were less than .05).
However, analyses with 7 additional markers showed that the mean number of methylated loci in BRAF mutant tumors (4.4) was the same as in KRAS mutant CRCs (4.3, P = .8610).
We aimed to study proliferation and survival effects induced by BRAF inhibition in MSI CRC cell lines harbouring distinct genetic backgrounds (BRAFV600E or KRAS G13D).
In addition, the combination of microsatellite instability testing, MLH1 promoter methylation analysis, and BRAF (V600E) mutation analysis can distinguish a sporadic colorectal cancer from one associated with HNPCC, helping to avoid costly molecular genetic testing for germline mutations in mismatch repair genes.
These results support that BRAF mutations harbour a mild oncogenic effect in comparison to KRAS and suggest that BRAF mutant colorectal cells need to accumulate extra epigenetic alterations in order to acquire full transformation and evolve to MSI CRC.
We analyzed sporadic CRCs in Omani (of African origin, N = 61), Iranian (of Caucasian origin, N = 53) and African American (N = 95) patients for microsatellite instability, expression status of mismatched repair genes (hMLH1, hMSH2) and presence of the BRAF (V600E) mutation.
The positive associations between folate intake and tumors harboring BRAF mutations and between vitamin B6 intake and those showing MLH1 hypermethylation were most pronounced among men and may suggest that these vitamins enhance colorectal cancer risk through genetic as well as epigenetic aberrations.
Clinicopathologic characteristics, CpG island methylator phenotype, and BRAF mutations in microsatellite-stable colorectal cancers without chromosomal instability.
The CpG island methylator phenotype (CIMP) with widespread promoter CpG island methylation is a phenotype in colorectal cancer, associated with microsatellite instability (MSI) and BRAF mutation.
Detection of the V600E hotspot mutation in BRAF oncogene is extremely useful for the screening of hereditary non-polyposis colorectal cancer (Lynch's syndrome) and for the prediction of sensitivity to MEK inhibitors.
KRAS and BRAF mutations in advanced colorectal cancer are associated with poor prognosis but do not preclude benefit from oxaliplatin or irinotecan: results from the MRC FOCUS trial.
CIMP-specific inactivation of BRAF(V600E)-induced senescence and apoptosis pathways by IGFBP7 DNA hypermethylation might create a favorable context for the acquisition of BRAF(V600E) in CIMP+ colorectal cancer.
MGMT and MLH1 promoter methylation versus APC, KRAS and BRAF gene mutations in colorectal cancer: indications for distinct pathways and sequence of events.
Synchronous colorectal cancers had more frequent mutations in BRAF, were more frequently CIMP- and MSI-high, and had a worse prognosis than solitary colorectal cancers.