Absence of IDH mutation in colorectal cancers with microsatellite instability

作者：Tougeron David^*; Guilloteau Karline; Karayan Tapon Lucie

来源：Digestive and Liver Disease, 2016, 48(6): 681-683.

DOI：10.1016/j.dld.2016.02.019

• Colon cancer
• Deficient DNA mismatch repair
• Isocitrate dehydrogenase

Background: Colorectal cancers (CRCs) with deficient DNA mismatch repair system (dMMR) represents approximately 12% of all CRCs. Sporadic dMMR CRCs are due to hypermethylation MLH1 gene promoter and associated with the CpG island methylator phenotype (CIMP). Isocitrate dehydrogenase (IDH) mutant tumors are associated with DNA hypermethylation in various cancers.
Aims: Look if dMMR CRC are associated with IDH mutations.
Methods: All consecutive dMMR CRCs between 2005 and 2014 were included in this study. Tumoral DNA used for dMMR analysis was also used to determine IDH1 and IDH2 mutations using pyrosequencing method.
Results: A total of 152 dMMR CRCs patients were analyzed. No IDH mutation was observed in dMMR CRC, nor in IDH1 or IDH2. Especially, no mutation was found in sporadic dMMR CRC which is known to be associated with CIMP.
Conclusions: In contrast with others types of hypermethylated tumors, dMMR CRCs are not associated with IDH mutations.

• 出版日期2016-6