RESUMO
Objective To study the relationship between the single nucleotide polymorphisms (SNP)of X-ray repair cross-complementing group-3(XRCC3),human 8-hydroxyguanine glycosylase-1 (HOGG1)gene of repair DNA and the radiosensitivity in esophageal squamous cell carcinoma(ESCC).Methotis Genome DNA was exracted from whole blood cells of ESCC patients.XRCC3 and HOGG1 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism method.The relationship was analyzed between SNP of XRCC3 Thr242 Met,HOGG1 Ser326 Cys and the response to radiotherapy in ESCC.Results Totally 199 ESCC patients were treated with radical radiotherapy.The response rate w88 81.4%.The response rate in patients with the XRCC3 Thr/Met genotype was significant higher than that in patients with Thr/Thr genotype(91.5%vs 77.1%,X2=5.67,P=0.017),with the same in HOGGlSet/Ser,Ser/Cys and Cys/Cys genotype(74.1%,84.2%,83.9%,X2=2.64,P=0.268).The esophageal radioactivity injury rate in patients with the XRCC3 Thr/Met genotype was also significant higher than that in patients with Thr/Thr genotype(35.6%vs 20.0%,X2=5.44,P= 0.020),with the same in HOGG1 Ser/Ser,Ser/Cys and Cys/Cys genotype(24.1%,24.6%,25.8%,X2=0.03,P=0.984).In Iogistic multivariate analysis,the SNP of XRCC3 was the independent influencing factor closely correlating with the mdiosensitivity of esophageal cancer(X2=16.12,4.43,P=0.009.0.035).No significant difierence was observed between the SNP in HOGG1 Ser326 Cys and the response rate of radiotherapy or the rate of esophageal radioactivity injury(X2=3.74,0.58,P=0.053,0.445).Conclusions SNP of XRCC3 Thr/Met is associated with the radiosensitivity in ESCC patients,which suggests that the XRCC3 Thr/Met SNP may be a predictor for ESCC patients who likely to response to radiotherapy.