| Objective: Lung cancer is one of the most common malignant tumors in the world.Non-small cell lung cancer(NSCLC)accounts for about 85% of lung cancer and has high morbidity,high mortality,high radiation tolerance and poor prognosis.micro RNA is a non-coding single-stranded RNA involved in the biological behaviors of proliferation,differentiation,stress response of tumor cells,migration and invasion.As one of its families,mi R-7 is closely related to tumorigenesis and radiosensitivity.PARP-1 is a polypeptide chain consisting of 1014 amino acid residues,located in the second band of the 4 region of chromosome 1 long arm.It plays an important role in the repair of DNA injury and the regulation of radiosensitivity,and its abnormal expression is closely related to the occurrence and development of tumor.Therefore,we investigate the relationship between mi R-7 and PARP-1,and the expression of PARP-1 and its clinical significance in postoperative NSCLC.Methods: 1.Online prediction software was used to predict the potential target genes of mi R-7 and the double luciferase gene report was used to prove.2.A549 and SK-MES-1 cells were transfected with mi R-7,mi R-7-inhibition and the empty vector.The transfection efficiency was verified by q RT-PCR.3.q RT-PCR and Western Blot were used to detect the expression of PARP-1 m RNA and protein in the transfected cells,and to further prove the regulatory effect of mi R-7 on target gene.4.The expression of PARP-1 m RNA and protein in transfected cells was observed by X-ray irradiation of 2Gy.5.Western Blot was used to detect the expression of PARP-1 in A549 and SK-MES-1 cells and normal human lung bronchial epithelial cell line 16 HBE.6.Immunohistochemistry was used to detect the expression of PARP-1 in 91 cases of NSCLC tissues and matched adjacent tissues.The correlation between the expression of PARP-1 and clinicopathological features and prognosis was analyzed.Results: 1.Double luciferase report showed that mi R-7 combined with PARP-1 by 3’UTR.2.Transfection of lentivirus to A549 and SK-MES-1 cell lines,q RT-PCR results showed that the expression of mi R-7 increased significantly after transfection of mi R-7,and the expression of mi R-7 decreased significantly after transfection of mi R-7-inhibition.3.After transfection of mi R-7 and mi R-7-inhibition into A549 and SK-MES-1 cell lines,q RT-PCR and Western Blot results showed that overexpression of mi R-7 could reduce the expression of PARP-1 m RNA and protein,and silencing mi R-7 could increase the expression of PARP-1 m RNA and protein.4.A549 and SK-MES-1 cell lines were transfected with mi R-7 for 2Gy X-ray irradiation,q RT-PCR and Western Blot results showed that PARP-1 m RNA and protein levels were significantly higher in 2Gy irradiated group than those in non-irradiated group;the levels of PARP-1 m RNA and protein in mi R-7+2Gy group were lower than those in mi R-7-NC+2Gy group.5.Compared with normal human bronchial epithelial cell line 16 HBE,the expression of PARP-1 was significantly increased in A549 and SK-MES-1 cell lines.6.The expression of PARP-1 in NSCLC tissues was significantly higher than that in paracancerous tissues,and there was no correlation between the expression of PARP-1 and clinicopathological features and prognosis.The clinical stage and the degree of tissue differentiation were related to the prognosis of the patients.Conclusions: PARP-1 is a target gene of mi R-7 and mi R-7 negatively regulates the expression of PARP-1.The expression of PARP-1 m RNA and protein were increased after 2Gy X ray irradiation.The expression of PARP-1 protein was highly expressed in NSCLC tissues.There was currently no correlation between the expression level and clinicopathological features and prognosis.Clinical stage and tissue differentiation are the factors influencing the prognosis of the patients with NSCLC after operation. |
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