BRAF, KRAS and PIK3CA mutations in colorectal serrated polyps and cancer: primary or secondary genetic events in colorectal carcinogenesis?
Our results show that BRAF, KRAS and PIK3CA mutations occur prior to malignant transformation demonstrating that these oncogenic alterations are primary genetic events in colorectal carcinogenesis. Further, we show that BRAF mutations occur in association with CIMP phenotype in colorectal serrated polyps and verified that colorectal serrated polyps and MSI CRC show a similar frequency of BRAF mutations. 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.
The hypothesis is rejected. For orthodontic patients with gingival inflammation, except for those with oral hygiene problems, the activation of COX-2 expression by orthodontic adhesive may be one of the potential mechanisms.