Molecular study of NRAS gene among Iraqi colorectal cancer patients

NRAS gene in colorectal cancer patients.

Abstract

Mutations in genes such as NRAS has become an important part of colorectal carcinoma evaluation. NRAS mutations occur in 3-5% of the colorectal cancer. The role of NRAS is differently from KRAS and BRAF mutation it plays as prognostic and predictive markers in metastatic colorectal cancer (mCRC) which has been investigated to a lesser extent. The aim of this study was to assess NRAS mutations frequencies in Iraqi colorectal cancer patients and find a correlation between these mutations with their gene expression. A total of 90 samples of FFPE (fixed formalin paraffin embedded tissue) consecutive stage 0-IV CRC tumor samples were analyzed for NRAS (exon 2 and 3) using direct sequencing and reverse transcriptase –polymerase chain reation (RT-PCR).The results of CRC mutations in NRAS gene(exon 2 and 3) is high in females than males. Sequencing in NRAS gene exon 2 and 3 shows a substitution mutation in different types of tumors in Iraqi colorectal cancer patients; also there is a high significant increasing between the substitutions mutations in exon 2 with it gene expression in early stages in CRC patients(P<0.01) .  Conclusion: Our results showed that frequency of NRAS mutations in Iraqi colorectal cancer is rare, which is very close to other studies from different geographic areas of the world. Further molecular studies   involving large patient series will be necessary to confirm these findings and to asses possible ethinic/environmtal and lifestyle influences on NRAS mutagenesis and to confirm the possible positive prognoses association with NRAS mutations and it gene expression.