Expression Of Nucleostemin In Non-Small Cell Lung Cancer Tissues And The Relevance Of MDM2 In Lung Adenocarcinoma Tissues

Lung cancer is one of the gravest and most common malignant tumors to human health and lives in the world, today. The incidence of lung cancer increases significantly because of smoking, air pollution,professional cancer risk factors and ionising radiation and so on. It is the first of malignant tumours in the city and third of the fastest growth of the rise in the country. Due to be lack of effective early diagnosis,most of lung cancer diagnosed by clinic are late. Though operation, chemotherapy and radiation are applied to treat lung cancer, the prognosis is still worse.So looking for some valuable tumor marker are potential value for the early diagnosis, treatment and follow-up.A p53-binding protein, named nucleostemin (NS) exclusively expressing in the stem cells, variation cells and tumors, has played an important role in maintaining stem cells and tumor cells to continue proliferation[1]. Literatures reports[2,3] that the level of NS is related to alarming extent of many malignant tumours,but it is unclear in non-small cell lung cancer (NSCLC) tissues. So this study detects the expression of NS in NSCLC tissues and furtherly researchs the relevance of NS and murine double minute 2 (MDM2) in lung adenocarcinoma tissues. Part 1 Expression of Protein and mRNA of NS in Non-small Cell Lung Cancer TissuesObjective:To investigate the expression and clinical significance of Nucleostemin(NS) gene in NSCLC tissues.Methods:We detected the NS expression in NSCLC and adjacent normal tissues by RT-PCR and immunohistochemical SP method, and analyzed the correlation between the expression of the NS protein and the clinical variables of NSCLC.Results : The mRNA and protein expression level of NS was significantly higher in the NSCLC than in the adjacent normal tissues. The positive rate of the NS protein expression was significantly higher in NSCLC than in adjacent normal tissue. NS staining in NSCLC tissues was correlated with classification and the degree of differentiation.The positive rate of NS protein expression was significantly higher in adenocarcinoma than in squamous cell carcinoma,which was also higher in poor grade than in moderate and well grade.Conclusion:The mRNA and protein of NS gene is overexpressed in NSCLC tissues, the worse the cells differentiate, the higher the NS gene expresses. The NS gene is closely related to the origination and development of NSCLC. Part 2 Expression of NS and MDM2 in Lung Adenocarcinoma Tissues and its SignificanceObjective:To analyze the expression of NS and MDM2 in lung adenocarcinoma tissues and its significance. Methods : NS and MDM2 protein expression were detected by immunohistochemical SP method in lung adenocarcinoma and adjacent normal tissues.Results:The positive rate of NS and MDM2 protein expression in lung adenocarcinoma was significantly higher than in the adjacent normal tissues. The expression rates of them were correlated with degree of differentiation and had a positive correlation, but had no correlation with the gender, age, tumor size, TNM stage and lymph node metastasis.Conclusion:Overexpression of NS gene plays an important role in the malignant proliferation of lung adenocarcinoma cells, and it may impact cell cycle via p53 pathway.