Association Of SNP Of Let-7Promoter Gene With Susceptibilities Of Lung Cancer

Aim: To demonstrate whether the single nucleotide polymorphism in the promoterregion of let-7family (rs10877887) is associated with susceptibility and clinical pathologiccharacteristics and prognosis of lung cancer.Materials and methods：Hospital based case-control research model was employedin our study.69patients were recruited from the department of the second affiliate hospitalof Soochow University from2006to2009.All patients were pathologically diagnosed withadenocarcinoma cancer after operation.75healthy volunteers were individuals from thesame hospital who were doing physical examination during the same period and matchedwell to the patient group on gender and age. According to previous studies, we chosen SNPrs10877887as a genetic marker in our study. The SNP was genotyped in cases andcontrols using direct sequencing. The relationship between genotypes, susceptibility, clinicpathological characteristics and prognosis of lung cancer were evaluated by unconditionalLogistic regression model, Kaplan-Meier analysis and other statistical methods.Results：1. Analyze of susceptibility：Compared with TT genotype, the CT genotype couldincrease cancer risk, and the CT+CC genotype carriers were more susceptible to lungadenocarcinoma cancer (OR=2.022，95%CI=0.999-4.089and OR=6.857，95%CI=1.425-33.008, respectively). We found the same conclusions in females over60years old.Furthermore, we also confirmed that the C allele may be a risk factor of lungadenocarcinoma cancer in these populations (OR=3.875，95%CI=1.303-11.520).2. Analyze of clinic pathological characteristics: The rs10877887C/T alleles werenot associated with any clinical pathological characteristics referred in our research.3. Analyze of prognosis: There was no significant correlation between thepolymorphism genotype distribution and prognosis of lung adenocarcinoma. TNM stage and lymphatic metastasis were considered to be influencing factors of AD. Individualswith lymph node metastasis had a higher risk of death than those without metastasis(p=0.000, OR=18.571，95%CI=5.536-62.298). And patients in stageⅡor Ⅲ~Ⅳ weremore likely to die than those in stageⅠ(p=0.000，OR=18.741,95%CI=4.478-78.423;p=0.000,OR=84.333,95%CI=7.848-96.204,respectively).The survival time was alsoconfirmed this point, namely, the MST was shorter and prognosis was worse if patients hadlymph node metastasis or in the late clinical stage.Conclusion：1. The CT genotype and CT+CC genotype of rs10877887have some relationshipswith lung cancer susceptibility. And the C allele maybe a risk factor in females over60years old.2. The SNP referred in our research have nothing to do with clinical pathologicalcharacteristics of lung adenocarcinoma cancer patients involved in our study.3. No relevance has been found between rs10877887polymorphism and survival oflung adenocarcinoma cancer, but lymphatic metastasis and TNM stage may affect patients’prognosis. Patients who have lymphatic metastasis or at the advanced TNM stage mayhave a poorer prognosis.