The Mechanism Of EPSH Involved In Lung Adenocarcinoma Progression And Chemo-radiation Therapy Resistance

Background Currently,lung cancer is the leading cause of cancer death worldwide,and its total 5 years survival rate was lower than 20%.In non-small cell lung cancer,adenocarcinoma was the highest incidence type among non-smokers,accounting for about more than 40% of all lung cancer,and its incidence is rising up year by year in our country.Furthermore,some countries(such as the United States)has surpassed squamous cell carcinomas in the leading place.In addition to surgery,radiation,chemotherapy and targeted therapy are important means for the treatment of lung adenocarcinoma.In order to better treat lung adenocarcinoma,and to prolong survival of cancer patients,individualized treatment of lung cancer is currently a field with constant improvement and updating,but still a large proportion of patients are insensitive to drug or radiotherapy,and even develop resistance.Improving the therapy for lung adenocarcinoma is becoming a hotspot and difficult problem.EPSH is a new type of regulator of membrane transport,but its relationship with lung adenocarcinoma and treatment sensitivity was unclear.We analyzed clinical data from surgical lung adenocarcinoma patients to explore EPSH in normal lung tissues and different subtypes of lung adenocarcinoma tissue for the expression and localization,demonstrating relationships between EPSH level and localization with the recurrence and survival of patients,and further studied its function in lung adenocarcinoma cancer cell proliferation,migration,and responses to treatments.Methods 1.Western Blotting and immunohistochemical was used to detect the expression level and localization of EPSH in lung adenocarcinoma tissue and matching adjacent normal lung tissue,and analysed the relationship between EPSH and the clinical pathological parameters of patients including survival.2.Western Blotting and immunofluorescence was used to detect endogenous EPSH expression and localization in a variety of lung cancer cells.3.Establishing EPSH and mutants expression in A549 cells,and Western Blottingwas used to study its function.4.Immunofluorescence and laser confocal microscope were also used to explore wild type and mutant functions.5.2D cloning and migration experiments to explore EPSH on cell proliferation and migration.6.Nude mice xenograft used to explore functions in vivo.7.Cisplatin and radiation resistant cell lines were established for functional study.Results: 1.Compared with adjacent normal lung tissue,EPSH expression level in cancer tissues was obviously downregulated;2.Survival analysis showed that EPSH nucleus expression group was better in 5 years DFS and OS(P = 0.014 & 0.004),and nuclear expression is an independent factor for postoperative recurrence and survival.3.EPSH levels was moderate in A549 cells,and almost no expression in PC9 cells,EPSH mainly located in cell membrane and cytoplasm in A549 cells,and EGFR and E-ca expression level are higher in PC9 cells.4.Laser confocal microscope showed that the EPSH and EGFR are colocalized in A549 cells,and after EGF stimulation,this phenomenon is more obvious.5.Experiments in vivo and in vitro confirmed different mutants of EPSH can affect the lung adenocarcinoma cancer cell proliferation,migration,and sensitivity to drug and radiation treatments;Conclusion: EPSH is a tumor suppressor of lung adenocarcinoma,and a potential regulator of cell resistance to radiation therapy.It may serve as a marker of disease prognosis and help in designing treatment approach in clinical practice.