| Background and Objective:According to the latest statistical research data of CA 2022,lung cancer is still one of the malignancies with the highest clinical incidence and mortality rate,and it has been on the rise in recent years.Despite the continuous efforts of basic and clinical researchers,various new oncologic treatments have been developed and continuously tried to improve the survival prognosis of lung cancer patients,based on the insidiousness of the onset of symptoms,most lung cancer patients have developed to advanced stages by the time they are diagnosed,such that the 5-year survival rate of lung cancer has remained at about 15%in recent years.Researchers now believe that cancer development is closely related to its unregulated and unlimited proliferation,and that tolerance to anticancer agents-such as resistance to the most common clinical antitumor drugs-is the more important factor affecting lung cancer prognosis in late treatment.Therefore,the search for initiating factors of tumorigenesis and triggers of drug resistance,and the exploration of potential therapeutic targets remains the focus of basic researchers and clinicians.The family of Aurora kinases is a group of serine/threonine kinases widely expressed in a variety of cells,with three members,Aurora-A,Aurora-B,and Aurora-C,which play important roles in mitosis,chromosome segregation,and spindle formation in eukaryotic cells.Previous studies have found that Aurora-B is closely associated with various tumorigenesis and is overexpressed in tumors of various origins,but the related functions and mechanisms remain to be further investigated.The functions and mechanisms involved in the Aurora-B and the development and drug resistance of non-small cell lung cancer have not been systematically studied.In this study,non-small cell lung cancer tissues,non-small cell lung cancer cell lines and nude mice were used as the study subjects.The protein expression levels of Aurora-B in paraffin specimens of non-small cell lung cancer tissues were examined and their relationship with clinical parameters was analyzed to provide histological evidence of Aurora-B involvement in the mechanism of non-small cell lung carcinogenesis development,and to explore the effects and possible mechanisms of Aurora-B gene expression on the proliferation ability and cisplatin resistance of non-small cell lung cancer cell using non-small cell lung cancer cell lines in vitro and in vivo,this provides a theoretical basis for the discovery of new targets for lung cancer diagnosis and treatment.Methods.1.Paraffin specimens of 174 non-small cell lung cancer tissues and 174 normal lung tissues were selected.We used immunohistochemistry in order to detect Aurora-B protein expression levels within the samples and statistically analyzed the correlation between the expression levels of Aurora-B protein and various clinical parameters.Analyze the relationship between Aurora-B expression levels and clinical prognosis according to the online database.2.Two cell lines with high Aurora-B expression and one cell line with low Aurora-B expression were selected from standard non-small cell lung cancer cell lines and their normal control cell lines,and the Aurora-B gene was down-regulated or overexpressed by gene interference technology.The proliferation ability of Aurora-B gene was examined in vivo and in vitro by subcutaneous tumor formation assay in nude mice,CCK8 proliferation curve assay,EDU assay,and plate clone formation assay.The protein levels and activity status changes of the pathway PI3K/AKT/NFκB（p65）were detected by Western Blotting.3.Using the high expression Aurora-B non-small cell lung cancer cell line A549and its cisplatin-resistant cell line A549/DDP,the expression of Aurora-B was down-regulated by gene interference technology,and to detect the change of cisplatin resistance compared with the cells before down-regulation.The change of apoptosis and the change of Aurora-B,p53,p21,BAX and TUBB3 and other resistance-related genes expression levels were examined.Results.1.The expression rate of Aurora-B protein was 62.07%（108/174）in 174NSCLC tissues and 32.76%（57/174）in control normal lung tissues,and the difference was statistically significant（P<0.01）.Aurora-B expression level was correlated with lymph node metastasis、the tumor TNM stage and tumor size in NSCLC,and negatively correlated with survival rate（P<0.01）.there was no significant correlation between Aurora-B protein expression and patients’age and gender（P>0.05）.2.Aurora-B showed high expression levels in A549 and H1299 cell lines and low expression levels in the normal lung epithelial cell line Beas-2B.Aurora-B levels are proportional to the ability of non-small cell lung cancer cells proliferation ability in vitro,4-week subcutaneous tumor volume and weight was significantly lower in the Aurora-B down-regulated group than in the negative control group.PI3K（p110）,p-AKT,p-NF-κB（p65）protein levels were decreased in Aurora-B down-regulated group.3.the IC50of A549/DDP against cisplatin was significantly higher than that of wild-type A549 cells.the expression level of Aurora-B in A549/DDP was higher than that of wild-type A549 cells,and after down-regulation of Aurora-B expression,the number of viable cells in A549/DDP cells treated with cisplatin was significantly reduced,and the IC50was significantly down-regulated.The expression levels of p53,p21 and BAX were significantly lower in A549/DDP than in wild-type A549,and the expression level of TUBB3,a drug resistance biomarker,was also significantly upregulated.after downregulating Aurora-B expression in A549/DDP,the expression levels of p53,p21 and BAX were increased and the expression level of TUBB3decreased.Conclusions.1.Aurora-B expression levels were higher in non-small cell lung cancer tissues than in the normal lung tissues,high Aurora-B expression levels were closely correlated with poor prognosis of non-small cell lung cancer.2.Aurora-B gene high expression promotes the proliferation of non-small cell lung cancer cells in vitro,Silencing of Aurora-B gene inhibits subcutaneous tumorigenic capacity of non-small cell lung cancer cells in nude mice.Aurora-B gene regulates cell proliferation by affecting PI3K/AKT/NF-κB pathway.3.High Aurora-B expression facilitates cisplatin tolerance in A549 cells.down-regulation of Aurora-B expression in A549/DDP cells can enhance their sensitivity to cisplatin.Aurora-B may promote drug resistance in A549 cells in vitro by regulating the levels of p53,p21,BAX and TUBB3. |
