| Objective To investigate the relationship between P53mutation, RARβmethylation and the clinical and pathological type of lung cancer, and to explore the relationship between P53mutation and RARβ methylation in lung carcinogenisis. Methods Using case-only study, collected samples of fresh cancer tissue from198primary lung cancer patients during the resection surgery, detected their mutation status of exons5through9in P53gene and methylation status of CpG islands in the promoter of RARβ gene by direct sequencing of PCR products and methylation-specific PCR respectively, and analyzed the result with questionnaire data by chi-square test and logistic regression analysis. Results P53mutation and RARβ methylation were detected in36.4%and58.1%tumors respectively. Patients with smoking history had an increased risk of both P53mutation and RARβ methylation with OR of2.41and2.26and cases with family history of lung cancer had a decreased risk of P53mutation with OR of0.26(all P<0.05). Both Smoking and P53mutation with smoking history increased the risk of squamous cell carcinoma, OR values were3.01and4.29, respectively; RARβ methylation increased the risk of peripheral lung cancer with OR of1.95; Both RARβ methylation and RARβ methylation with P53mutation increased the risk of advanced lung cancer, OR values were2.13and3.06respectively (all P<0.05). Compared with tumors with unmethylated RARβ, P53G:Câ†'T:A mutation rate and mutation proportions were higher in tumors with RARβ methylation with statistically significant (all P<O.05). P53G:Câ†'T:A mutations increased the risk of detecting RARβ methylation with OR of3.22, and the risk increased to3.65and4.71fold in patients with smoking history and in cases with squamous cell carcinoma respectively (all P<0.05). Conclusion P53mutation, RARβ methylation and smoking were closely related to the clinical and pathological type of lung cancer. RARfβ methylation was associated with P53G:Câ†'T:A mutations during the lung cancer pathogenesis. |
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