TP53 somatic mutations and LOH profile in colorectal cancer in Romania

Somatic mutations in TP53 tumor suppressor gene represent common events in colorectal cancer, followed frequently by loss of heterozygosity in the course of disease progression. In order to study the profile of these genetic alterations in Romanian oncologic patients TP53 gene sequencing and loss of heterozygosity analysis were performed in 62 tumor samples and 60 paired normal colon tissue samples collected during curative surgical resection. The rate of TP53 somatic mutations (46.8%) was concordant with published data while the type of mutations and their association with tumor sites exhibited a different pattern. The most prevalent mutation type was the nucleotide transition GC>AT (62.1% of total mutations) that occurred exclusively at the CpG dinucleotide sites. Allelic imbalance at TP53 locus was detected in 50% of colorectal tumors. The geographical variation of CRC might be explained by large differences in lifestyle habits and diet across various regions and ethnical groups. However, larger studies are needed to identify and characterize the distinct features of the colorectal cancer mutational profile in respect to geographical location, combined also with nutrigenomics analysis of the particular dietary nutrients specific for the region.