Expression And Significance Of HTERT MRNA In Non-small Cell Lung Cancer And Its Relation To P53

ObjectiveToday lung cancer is the leading cause of cancer-related death world-wide.The etiopathogenisis of lung cancer is quite complicated,and is generally considered to be of multiple factors.Many researches find that the generation of lung cancer is closely related to activation of telomerase and proto-oneogene,inactivation of anti-oncogene.Telomerase is a kind of reverse tranceriptase composed of RNA and proteins.It can synthesize telomere DNA with its own RNA as template,thus telomere avoids to shorten.As we know,beeause of the existence of extreme duplication problem,after each cell division,telomere will shorten a little,which will lead to apoptosis.Most human cells don not express telomerase,however,in certain factors,telomerase will be reactivated and precipitate cellular canceration.p53 gene locates at human chromosome 17P with a length of 20kb,which has 11 extrons and encodes a nuclear phosphoprotein(relative molecular weight5.3×10~3D) Composed of 393 amino acids.Usually,p53 gene has two types.One is wild,the other is mutant.The former is recognized as a kind of anti-oncogene,such as ras,myc and so on.which can induce terminal differentiation,maintain gene stable,trigger aging and apoptosis.While the latter has no function of anti-cancer,inversely,it can inhibit activity of wild p53 and precipitate cellular canceration.In this study,in order to identify the expression of hTERTmRNA and p53 gene in NSCLC tissues and normal lung tissue,and make clear their relations and clinical signifieance,in situ hybridization and immunohistoehemieal streptavidi peroxidase(SP)method has been used to examine the expression of hTERTmRNA and p53 protein.Methods The expressions of hTERTmRNA and p53 protein was examined by in situ hybridization and immunohistochemistry in 38 cases of NSCLC tissue and 22 cases of normal lung tissue.Results1.The expression of hTERTmRNA among different group lung tissuesThe positive rate of hTERTmRNA in normal lung tissues and NSCLC tissue was 0%and 78.94%(P＜0.01)respeetively.2.The relation of hTERTmRNA with the clinical and pathological charaeteristies of NSCLC hTERTmRNA was closely related to differenntion grades and TNM stages(P＜0.05),but not to sex,age,lymph,node metastasis and histological types.(P＞0.05)3.The relationship between the expression of hTERTmRNA and p53 in NSCLCThe expression of hTERTmRNA was positively associated with that of p53.Conclusion1.hTERTmRNA was not expressed in normal lung tissues,while significantly expressed in NSCLC,which indicated the activity of hTERTmRNA existed universally in NSCLC.2.hTERTmRNA was closely related to differenntion grades and TNM stages,but not to sex,age,lymph node metastasis and histological types.3.The activity of hTERTmRNA within hTERTmRNA with p53 positive is higher than that within NSCLC.with p53 negative,which indicates that the expression of p53 protein is likely related with the active regulation of telomerase.