Inhibition Of Ulkl Suppresses Non-Small Cell Lung Cancer Cell Proliferation And Sensitizes Cells To Cisplatin

Backgroud Autophagy is a process of phagocytosis of unnecessary or dysfunctional components,fusion with lysosomes and degradation of the contents of the lysosomes to maintain cellular homeostasis.Autophagy is now widely implicated in pathophysiological processes and participated in a variety of diseases,including lung cancer.Autophagy has both positive and negative functions in cancer.Uncoordinated(Unc)51-like kinase 1(Ulk1),a serine/threonine kinase,plays a central role in the autophagy pathway.Ulkl promotes cell survival of several cancers.Moreover,overexpression of Ulkl has been shown to negatively correlated with the prognosis of a variety of cancers.However,the role of Ulkl in non-small cell lung cancer(NSCLC)remains unclear.Lung cancer is the most frequently diagnosed cancer and the leading cause of cancer death,has became a major public health problem worldwide.NSCLC accounts for 85%of lung cancer cases,and is resistant to chemotherapy and radiotherapy.The 5-year overall survival rate of patients with NSCLC is very low.Cisplatin is the most common drug for NSCLC,but intrinsic and acquired cisplatin resistance limits its efficacy in lung cancer treatment.Thus,the identification of new therapeutic targets for NSCLC and new methods to enhance the sensitivity of cisplatin for NSCLC would be of great value.Objective This research majors to make it clear the expression of Ulkl in non-small cell lung cancer,and the roles of Ulkl and SBI0206965 in the proliferation,apoptosis and chemosensitivity of cisplatin in non-small cell lung cancer cells.Methods(1)By searching the Oncomine Gene Profiling Database to analyze the expression difference between normal tissues and non-small cell lung cancer.Through western-blotting to analyze the difference of Ulkl expression between non-small cell lung cancer cells(A549,H460,H292,HCC827 and H1975)and normal human lung cell line(BEAS-2B).(2)Through searching of an online Kaplan-Meier plotter database to analyze the relationship between the expression of Ulkl and the prognosis of lung cancer.(3)Knockdown of Ulkl or inhibiting Ulkl by a specific Ulkl inhibitor,SBI0206965,to analyze the role of Ulkl in cell proliferation and apoptosis in non-small cell lung cancer cells.(4)Knockdown of Ulkl or inhibiting Ulkl by a specific Ulkl inhibitor,SBI0206965,to analyze the role of Ulkl in chemosensitivity in non-small cell lung cancer cells.(5)Through MDC staining,AO staining,GFP-LC3 spot and western-blotting to analze the probably mechanisms of Ulkl and SBI0206965 in non-small cell lung cancer cells.Results(1)The results of Oncomine Gene Profiling Database and western-blotting showed that the Ulkl is over expressed in non-small cell lung cancer tissues and cells;(2)The results of the Kaplan-Meier plotter database showed that the expression of Ulkl is negatively correlated with prognosis of lung cancer patients.(3)Knockdown of Ulkl inhibited cell proliferation and enhanced the sensitivity of cisplatin against non-small cell lung cancer cells.(4)Inhibition Ulkl by SBI0206965 inhibited cell proliferation and enhanced the sensitivity of cisplatin against non-small cell lung cancer cells.(5)Knockdown of Ulkl or inhibiting Ulkl by SBI0206965 decressed the numbers of GFP-LC3 dots,the levels of LC3 II/LC3 1,increased the level of p62,and decrease the protein levels of Bcl2/Bclxl.(6)Conclusions In summary,our study showed that NSCLC cell lines exhibited high expression of Ulkl and that Ulkl was negatively correlated with prognosis of lung cancer patients.Knockdown of Ulkl or the inhibition of Ulkl by a selective inhibitor,SBI0206965,inhibited cell proliferation and enhanced the sensitivity of cisplatin in NSCLC cells.The possible mechanisms by which SBI0206965 kills cancer cells are the inhibition of autophagy and reduction of Bcl2/Bclx1 levels.