Expression Of PLK1 In NSCLC And Its Significance

ObjectiveLung cancer is the leading cause of cancer deaths worldwide. An estimated 500000 new cases of lung cancer are diagnosed in China every year, among which 80%-85% cases are NSCLC (Non Small Cell Lung Cancer). At present, the outcome of it is not satisfactory. Only 15% of all lung cancer patients are alive 5 years or more after diagnosis. More and more medical researches focus on looking for gene markers, which correlate with lung cancer and could be used for early diagnosis and judgment of prognosis, risk of recurrence and metastasis, even for target of genetic therapy.PLK1(polo-like kinase 1) is considered to be closely related with mitosis. Recently many researches revealed that the over-expression of PLK1(or PLK) were found in various primary carcinoma, including lung cancer and indicated the relationship between PLK1 and human cancers biological feature and prognosis are very tightly.The purpose of this study was to determine whether PLK1 is over-expressed in surgical specimens of NSCLC lung cancer as compared with normal pulmonary tissue and to assess its relation to pathological classification TNM staging and metastasis by immunohistochemical method.MethodsIn the present study, immunohistochemical method was performed to detect PLK1 and P53 in 63 primary Non small cell lung cancers as well as 10 normal pulmonary specimens. Pathological TNM staging was performed according to UICC1997 protocol. SPSS 13.0 for Windows Software was used to analyze Statistical data.ResultsPositive staining for PLK1 was observed in 79.4% of the NSCLC specimens, and negatively in normal pulmonary specimens. The expression level elevation in the malignant group was statistically significant compared with that of the normal group.There were no significant associations between PLK1 and histological type, and grade. PLK1 expression was significantly related to the size of tumor, lymph node metastasis and TNM staging. In NSCLC P53 expression was significantly associated with PLK1.Conclusion1 the over-expressed PLK1 in primary Non Small Cell Lung Cancer specimens, compared with that of normal pulmonary specimens, indicated that PLK1 was a new tumor marker for NSCLC.2 PLK1 expression level in NSCLC have correlation with the lymph node metastasis and TNM staging. It indicated that PLK1 might be a prognostic market3 No statistical significance was found between the PLK1 expressions of different pathological types and grades.4 Statistical relation was found between the PLK1 expression level and the accumulation of P53, which indicated P53 might be one of the targets of PLK1.