Association Study Of The XRCC1 Gene With Sporadic Breast Cancer In Inner Mongolia

Objective To select two sites in the X-ray repair cross complementing group1(XRCC1)rsl799782 and rs25487,to investigate of the polymorphisms of XRCC1 and the expression of XRCC1 protein in breast cancer and adjacent tissues,to explore the correlation of sporadic breast cancer in Inner MongoliaMethods 1.Collected the patients from the Affiliated Hospital of Inner Mongolia Medical University December 2017 to December 2018 breast surgery and confirmed by pathology:103 cases of primary sporadic breast cancer patients(case group:65 cases of the Han nationality,38 cases of Mongolian),103 cases of normal physical examination wormen(control group:65 cases of the Han nationality,38 cases of Mongolian).Extracted DNA from blood samples by using polymerase chain reaction(PCR)and direct sequencing methods to analyze the XRCC1 gene rsl799782 and rs25487 loci polymorphism.Collected and collated the clinical data.In order to ensure the quality of the input data,all the data excel double entry,checked and analyzed statistically.The XRCC1 gene rsl799782 and rs25487 the distribution of genotype frequencies were in Hardy-Weinberg equilibrium test.SPSS21.0 statistical software for experimental data and the clinical pathological characteristics:age,ER(estrogen receptor),PR(progesterone receptor),HER-2(human epidermalgrowth factor receptor-2),clinical stage,and lymph node metastasis,the results were statistically analyzed P<0.05 was considered statistically significant.2.Collected 64 cases(32 cases of the Han nationality,32 cases of Mongolian)of breast cancer tissues and adjacent tissues(?2cm adjacent of malignant tumor),selected 20 cases of benign tumor tissues,use the immunohistochemical Envision method to detect the expression of XRCC1 protein in all tissue specimens.Then use chi-square test to analyze the difference among the expression of XRCCI in three groups and the relationship between expression of XRCCland and the clinical pathological characteristics:age,ER(estrogen receptor),PR(progesterone receptor),HER-2(human epidermalgrowth factor receptor-2),clinical stage,and lymph node metastasis P<0.05 was considered statistically significant.Results In case group aged 32-81 years old,the average age was 54.40±9.899 years old.The two national samples in age,ER,PR,HER-2,clinical stage and lymph node metastasis,the distribution of the difference was not statistically significant.The control group aged 32-80 years old,the average age was 53.95±9.823 years old,no significant difference in the control group in age,case group and the control group the difference was not statistically significant.1.In this experiment,no matter Han or Mongolian,rs 1799782 loci can be detected 3 kinds of genotypes:CC,CT and TT.The 3 kinds of genotypes of Han nationality in case group respectively:35.38%(23/65),53.85%(35/65),10.77%(7/65).The Mongolian case group can be detected 3 kinds of genotypes,respectively:60.53%(23/38),34.21%(13/38),5.26%(2/38).In case group,the XRCC1 gene rs 1799782 loci of the homozygous wild type CC was increased and the heterozygous CT was decreased in Mongolian case group,the difference was statistically significant(X2=6.210,p=0.045).The results rsl799782 loci showed difference between the Han and Mongolian nationalities in the case group.2.To investigate the correlation of the polymorphisms of XRCC1 and the clinical pathological characteristics,there was a low correlation between rs 1799782 genotype and PR(r=0.234).3.In this experiment,no matter Han or Mongolian,rs25487 loci can be detected 3 kinds of genotypes:AA,AG and GG.The polymorphism of rs25487 locus was not detected difference in Mongolian and Han nationality 4.In breast adjacent tissues and benign breast tumors the expression of XRCCI protein was significant increased(x2=33.329,P<0.001).There was no significant difference in the expression between the Han and Mongolian nationalities.(P>0.05)Conclusion 1.The results rs 1799782 loci showed difference between the Han and Mongolian nationalities in the case group.2.There was a low correlation between rs 1799782 genotype and PR.3.rs25487 may be related to the occurrence and development of sporadic breast cancer in Inner Mongolia the correlation is not obvious.4.XRCC1 protein was showed lower expression in breast cancer tissues than breast adjacent tissues and benign breast tumors.