Risks of Fas and FasL polymorphisms in Taiwan OSCC patients

Objectives: Cancer tissue displays high levels of Fas Ligand (FasL) and low levels of Fas in the cell surface to escape the control of immune surveillance. The effects of functional polymorphisms of the Fas and FasL genes on risk of oral squamous cell carcinoma (OSCC) are unclear. Our aim was to determine the association between Fas - 670A>G and FasL -844C>T polymorphisms and OSCC.

Methods: We collected 267 OSCC patients from Kaohsiung Medical University Hospital and 268 healthy controls from a community health survey in Southern Taiwan. After inform consent, peripheral blood was collected for DNA extraction and a standardized questionnaire was applied to collect demographic data, and potential confounding factors. Genetic polymorphisms were determined using PCR-RFLP techniques. JMP statistical software was used to analyze the association.

Results: OSCC patients had higher frequencies in the habits of substance usage than the controls had. No differences in the distributions of Fas -670A>G and FasL-844 C>T polymorphisms were found between healthy controls and OSCC patients, even to stratify with the habits of substance usage. However, the ORs of betel quid chewing (OR=37.25, 95%CI =6.72-317.48; OR=19.27, 95%CI=8.41-47.61; OR=8.60, 95%CI =2.83-27.09, respectively) and cigarette smoking (OR=8.68, 95%CI=1.26-67.16; OR=3.43, 95%CI=1.48-7.71; OR=6.39, 95%CI=2.21-18.33, respectively) to OSCC were influenced by Fas -670G/G, A/G, and A/A genotypes. The ORs of betel quid chewing (OR=21.80, 95%CI=8.50-61.45; OR=12.45, 95%CI=5.28-31.04, respectively) and cigarette smoking (OR=3.40, 95%CI=1.17-9.53; OR=5.91, 95%CI =2.68-12.91, respectively) to OSCC were influenced by FasL -844T allele, and C/C genotype.

Conclusions: We suggest that Fas-670A/G and FasL -844 C/T polymorphisms are not associated with OSCC. However, the risks of cigarette smoking and betel quid chewing to OSCC can be influenced by the Fas-670A>G and FasL-844C>T polymorphisms.