| Objective: Observe the protein expression level of CYP1A1 of different pathological grades of cervical cancer specimens, to explore the relationship between the expression of CYP1A1 and the cervical cancer development. Detect the correlation of MspI polymorphism and Ile/ Val polymorphism with cervical cancer susceptibility, to reveal the possible molecular mechanisms of the CYP1A1 gene in the pathogenesis of cervical cancer. Observe the effect of the different concentrations of As2O3 on the Benzopyrene -induced CYP1A1 expression in HeLa cells, to provide theoretical and experimental basis for clinical therapy of cervical cancer.Methods: Paraffin specimens of 132 cases were collected: 112 cases in which were cervical squamous cell carcinoma (test group), which is divided into three groups according to histological grade:Ⅰgrade 21 cases,Ⅱgrade 52 cases,Ⅲgrade 39 cases; 20 cases of normal cervical tissues were collected (control group).Immunohistochemistry chain enzyme avidin - peroxidase (SP) method was used to detect the protein expression of CYP1A1. Collecting blood samples from 176 cases of Cervical cancer patients and 100 healthy women over the same medical examination period, PCR-RFLP and allele specific PCR (as-PCR) analysis were used to detect CYP1A1 gene MSPI polymorphisms and 3 Ile / Val genotypes and allele frequency distribution. Real-time fluorescence quantitative PCR and Western blot method were used to detect the effect of different concentrations of arsenic trioxide (As2O3) on Benzopyrene -induced CYP1A1 mRNA and protein expression in HeLa cells.Results:1. The positive rate of CYP1A1 expression was 25.0% in normal cervical tissue, and the positive rate of CYP1A1 expression in cervical squamous cell carcinoma was 61.1%, which was significantly higher than control group (P <0. 01). The positive rate of CYP1A1 protein in cervical squamous cell carcinoma ofⅠ,Ⅱ,Ⅲgrade was 42.8%, 55.7%, 79.4% respectively. The positive rate of CYP1A1 protein in squamous cell carcinomaⅡ,Ⅲgrade was higher than the control group (P <0. 05), and the protein expression of CYP1A1 in squamous cell carcinomaⅢgrade was higher than squamous cell carcinomaⅡgrade (P <0. 05).2. The differences of CYP1A1 gene MspI restriction site and the allele C T genotype frequency distribution between test and control groups were not statistically significant (P>0.05); In the case group three genotypes Ile / Ile, Ile / Val, Val / Val were 19.3%, 68.8% and 11.9% respectively; allele frequency of Ile, Val were 53.7% and 46.3%, which had a significant difference compared with the control group(P <0. 05).3. The expression of CYP1A1 mRNA in 7.5μmol/L B (a) P treatment group was significantly elevated compared with control group (P <0.05). The expression of CYP1A1 mRNA in 7.5μmol/L Benzopyrene-induced HeLa cells with different concentrations of As2O3 treatment for 24 h was significantly decreased compared with the 7.5μmol/L B (a) P treated group (P <0.05). Results of western blot showed that the protein expression of CYP1A1 in 7.5μmol/L Benzopyrene-induced HeLa cells was significantly elevated compared with control group (P <0.05); the protein expression of CYP1A1 in 7.5μmol/L Benzopyrene-induced HeLa cells with different concentrations of As2O3 for 24 h was significantly decreased compared with 7.5μmol/LB (a) P treated group (P <0.05).Conclusion: 1. CYP1A1 expression in cervical tissue may play a role in the occurrence and development of cervical squamous cell carcinoma; 2. Cytochrome CYP1A1 gene Msp I polymorphisms has no relationship with the cervical cancer susceptibility, and CYP1A1 gene Ile / Val are strongly associated with the cervical cancer susceptibility. 3. As2O3 significantly inhibited the expression of CYP1A1 in B (a) P-induced HELA cells in a manner of dose-dependent. |
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