Detection of Three Novel Mutations in Exon 7 of FGFR3 Gene in Iraqi Patients with Bladder Cancer

Abstract

The present study was carried out in Genetic Engineering and biotechnology Institute –Baghdad University during a period from October 2013 to October 2014, for detecting the role of genetic alterations of FGFR3 gene in Iraqi patients with bladder cancer. 50 patients with bladder cancer who admitted to Ghazi AlHariri Hospital in Baghdad and 25 healthy persons (age between 30 to 86 years) were included in this study. Total genomic DNA was isolated from blood samples for molecular analysis using specific primers for exon 7 of the gene FGFR3. The PCR amplified regions of the FGFR3 exon 7 of healthy and patients showed a molecular weight of about 120 bp. The analysis of mutation using restriction fragment length polymorphism (RFLP) was performed on PCR products of FGFR3 exon 7 using Hae II and TseI enzymes. These results showed that the PCR amplified regions of the FGFR3 exon 7 has only one restriction site for each enzymes. The REFLP molecular analysis of FGFR3 exon 7 of patient samples for both enzymes revealed one mutation in one patient include FGFR3 Arginine 248 Cysteine  mutation. The DNA sequencing analysis of the exon 7 PCR products revealed that among 50 patients included in this study, 51 mutations were detected in exon 7. The mutations detected in exon 7 include three types, g.13515 del C , g.13510 del A and g.13529 ins A. The more frequent mutation was g.13515 del C which detected in 34 patients followed by g.13510 del A and g.13529 ins A mutations which detected in 12 and 1 patients respectively. The A insertion mutation (13529) were included in the Hae II restriction site which explain the single mutation detected in patients. The results showed that the exon 7,  g.1315 delC mutation is a correlated with the initiation of tumor since it detected in all grads and consist of the majority of detected mutations (36/81, 44.4%). On the other hand, exons 7 mutations, g.13529 ins A, g.13510 del A, showed to have importance in cancer initiation and development since they are detected in the early grade (G1) and in 38(80.9%) patients of 47.

Key words: Bladder carcinoma, FGFR3, RFLP, g.1315 delC, g.13529 ins A, g.13510 del A