Abstract:

Objective To investigate the single nucleotide polymorphism (SNP) and loss of heterozygosity (LOH) of fibroblast growth factor receptor 4 (FGFR4) gene in gastric carcinoma, and explore their roles in oncogenesis, progression and prognosis of gastric carcinoma. Methods The SNP of FGFR4 gene exon 6, 9, 13, 16 and 18 of 50 cases of gastric carcinoma was detected. The LOH of rs351855 of coden 388 in FGFR4 gene exon 9 was determined by SNP technique. The correlation of SNP and LOH of FGFR4 gene with clinicopathology of gastric carcinoma and survival of patients was analysed. Results There was somatic mutation of coden 401 (R401C，C>T) in FGFR4 gene exon 9 in 1 case, non-synonymous SNP was detected in 34 cases of gastric carcinoma with the percentages of GG genotype, AG genotype and AA genotype being 32%, 52% and 16% respectively, and the frequency of LOH of rs351855 was 92.31% in 26 case of gastric carcinoma with AG genotype. There was no significant difference in the expression of Arg388 allele and frequency of LOH among different degrees of differentiation, tumor stages, lymph node status, pTNM classification and time of survival (P>0.05). Conclusion High frequency of LOH of rs351855 of coden 388 in FGFR4 gene in patients with gastric carcinoma suggests that there is absence or inactivation of tumor suppressor gene nearby. The expression of Arg388 allele and LOH of rs351855 in FGFR4 gene are not associated with the progression and prognosis of gastric carcinoma.

Key words: gastric carcinoma, fibroblast growth factor receptor 4, single nucleotide polymorphism, loss of heterozygosity, tumor suppressor gene