| Background information and objective: As the most serious malignant tumors of the health and the most important causes of death worldwide,the morbidity and mortality of lung cancer grow up rapidly in china for recent decades.According to the biological and prognostic characteristics,responsiveness to chemotherapy,the World Health Organization divided lung cancer into small cell lung cancer and non-small cell lung cancer,among which non-small cell lung cancer is the most common subtype of lung cancer,accounting for 80-85% of all lung cancer.Poly ADP-ribose polymerase-1(PARP-1),also known as adenosine diphosphate-ribosyltransferases(PART-1),functions as aproteolytic enzyme which maintains chromatin structure stability,participates in DNA repairmen process,regulated apoptosis,necrosis,and cell differentiation related transcriptional process.At the same time,NF-?B,as an important transcription factor in living organisms,can regulate the expression of various genes such as cytokines,growth factors and adhesion molecules,and many studies have discovered that selective activation or expression of NF-?B is highly up-regulated in tumor owing to the depression of its negative regulatory protein NF-?BI?.However,the role of PARP-1 and NF-?BI? in the development of non-small cell lung cancer is still unclear.In order to find new targets for clinical diagnosis and treatment of non-small cell lung cancer,this study aimed to investigate the role and genetic polymorphism of PARP-1 and NF-?BI? in the development of Chinese non-small cell lung cancer and search for key therapeutic targets for non-small cell lung cancer treatment.Part one: detection of PARP-1 and NF-?B genes expression in non-small cell lung cancer and analysis of their correlations with clinical survival indicatorsMethods: 54 cases of non-small cell lung cancer resection specimens in department of thoracic surgery,the first affiliated hospital of Anhui Medicial University,were collected from March 2011 to December 2012,including 54 specimens of cancer tissues and tumor adjacent tissues.The protein expression kurtosis of PARP-1 and NF-?BI? in tumor and tumor adjacent tissues was detected by immunohistochemistry and immunoblotting detection.The protein expression levels of PARP-1 and NF-?BI? were calculated by semi-quantitative analysis: Each tissue sample was analyzed according to the immunohistochemical staining intensity and staining range.The staining intensity was divided into four grades: 0=negative,1=weak positive,2=medium positive,3=strong positive.The staining range is divided into 5 levels: 0 = 0%,1 = 1-10%,2 = 11-50%,3 = 51-80%,and 4 = 81-100%.The scores of staining intensity and staining range were multiplied to obtain the integral of immunohistochemistry(IHC score).If IHC score?6,the gene was defined highly expressed while<6 points gene was considered low expressed.Correlation analysis:1.Analyze the correlation and difference of the expression levels of PARP-1 and NF-?BI? in paired lung tumor tissues and tumor adjacent tissues.2.Analyze the correlation between the expression levels of PARP-1 and NF-?BI? and clinical survival factors and pathological types of patients.Result: 1.Compare the protein expression of PARP-1 and NF-?BI? gene protein expression in tumor and tumor adjacenttissue from 54 paired cases of non-small cell lung cancer patients and found that PARP-1 and NF-?BI? genes expression are increased in cancer tissues(P < 0.05).Moreover,the expression of PARP-1 and NF-?BI? genes in unpaired non-small cell lung tumor tissues and tumor adjacent tissues were also significantly increased(P<0.05).2.Kaplan-Meir survival curve analysis and multivariate Cox risk regression model found that there is a correlation between the high expression of PARP-1 in cancer tissues and the survival of non-small cell lung cancer patients,suggesting that PARP-1 may be an independent poor prognostic factor for patients with non-small cell lung cancer.Conclusion: 1.Immunohistochemistry and Western blotting showed significant differences in the expression of PARP-1 and NF-?BI? genes in non-small cell lung cancer tissues and adjacent tissues.The expression of PARP-1 and NF-?BI? in cancer tissues was significantly increased.2.The expression of PARP-1 in tumor cells is correlated with the disease free survival of patient,suggesting that PARP-1 can not only be used as an anti-tumor therapeutic target for non-small cell lung cancer patients,but also an important monitoring indicator of patient prognosis and disease progression.Part two: Relationship between genetic polymorphism of PARP-1 and NF-?BI? and non-small cell lung cancerMethods: Peripheral blood and complete clinical data of 210 non-small cell lung cancer patients and 280 healthy control people in the department of thoracic surgery,the first affiliated hospital of Anhui Medical University were collected.DNA extracted from peripheral blood leukocytes of patients by high-salt DNA extraction,and then PARP-1 and NF-?BI? gene in DNA samples were detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).Genotyped were analyzed to compare the relationship between different genetic polymorphisms and the development of non-small cell lung cancer.Results: 1.The allelic frequency distribution of the PARP-1-1672 and NF-?BI?-519 gene in non-small cell lung cancer group and healthy control group is in accordance with the Hardy-Weinberg genetic balance rule.The distribution characteristics of PARP-1 and NF-?BI? genes were universal in general population(P>0.05).2.The smoking history was statistically different between the non-small cell lung cancer group and the healthy control group.There were 128 patients with a history of smoking in the non-small cell lung cancer group,accounting for 60.9%,while 76 cases in healthy control group,accounting for 27.1%.There was a statistically difference in smoking history between the two groups(P=0.021).The smoking proportion in cancer group was significantly higher than that in the healthy control group.3.Distribution of PARP-1-1672 genetic polymorphism in non-small cell lung cancer group and control group Logistic regression analysis showed that the heterozygous mutant GA at the PARP-1-1672 gene had a statistically significant effect on the incidence of non-small cell lung cancer(P=0.003,OR=1.942,95% CI=1.481-2.310),resulting in a significant increase in the risk of developing non-small cell lung cancer.4.Distribution of NF-?BI?-519 genetic polymorphism in non-small cell lung cancer group and control group Logistic regression analysis showed that the heterozygous mutant AG at NF-?BI?-519 gene had a statistically significant in the pathogenesis of non-small cell lung cancer(P= 0.0041,OR = 2.175,95% CI = 1.881-2.509),which might cause an increase risk of non-small cell lung cancer.5.Analysis of the interaction between polymorphisms in the PARP-1-1672 and smoking historyThe OR value of smoking history alone was 1.971(95% CI=1.690-2.274)while the OR value of the PARP-1-1672 heterozygous GA genotype alone was 1.942(95%,CI=1.481-2.31),statistically significant for the incidence of non-small cell lung cancer,but the interaction analysis found P value was over 0.05,suggesting PARP-1-1672 heterozygous mutation GA genotype and smoking history had no interaction in the development of lung cancer.6.Analysis of the interaction between genetic polymorphisms of NF-?BI?-519 gene and smoking history The OR value of smoking history alone was 1.971(95% CI=1.690-2.274),which was statistically significant in the pathogenesis of non-small cell lung cancer.The OR value of the NF-?BI?-519 heterozygous AG genotype alone was 2.175(95% CI=1.881-2.509),statistically significant for the incidence of non-small cell lung cancer.The interaction analysis found OR was 1.233(95% CI = 1.011-1.548),suggesting NF-?BI?-519 heterozygous mutation AG genotype has an interaction with smoking history in the development of non-small cell lung cancer,leading to an increase risk of non-small cell lung cancer.7.Analysis of the interaction between PARP-1-1672 and NF-?BI?-519 genetic polymorphism in the development of non-small cell lung cancer The OR value of the PARP-1-1672 homozygous mutant AA was 0.946(95% CI=0.813-1.207),which had no statistically significant effect on the occurrence of non-small cell lung cancer,but had an interaction with NF-?BI?-519 heterozygous AG type,and the OR value was 1.322(95% CI=0.398-1.804),confirming the PARP-1-1672 homozygous mutation AA type interacted with the NF-?BI?-519 heterozygous mutation AG type and significantly increased the risk of non-small cell lung cancer.Conclusion: 1.The allelic frequency distribution of PARP-1-1672 and NF-?BI?-519 in non-small cell lung cancer group and control group was in accordance with Hardy-Weinberg genetic balance rule.2.The PARP-1-1672 heterozygous mutant GA has a statistically significant effect on the pathogenesis of non-small cell lung cancer(P=0.003),causing an increasing risk of non-small cell lung cancer.3.The effect of NF-?BI?-519 gene heterozygous mutant AG on the pathogenesis of non-small cell lung cancer was statistically significant(P=0.0041)resulting in an significant increase risk of non-small cell lung cancer.4.The NF-?BI?-519 heterozygous mutation AG genotype has an interaction with smoking history in the development of non-small cell lung cancer.5.The interaction between PARP-1-1672 homozygous mutation AA and NF-?BI?-519 heterozygous mutation AG significantly increased the risk of non-small cell lung cancer... |
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