Interaction Of Sox2 And CtBP1 In Promoting LADC Metastasis Through EMT And The Mechanisms

ObjectiveTo investigate the expression of Sox2 and CtBPl in human lung adenocarcinoma,and the interaction of Sox2 and CtBP1 in promoting LADC metastasis through EMT and the mechanisms.Methods1.Immunohistochemistry was used to detect the expression of Sox2,CtBP1 and EMT marker.Analyze the correlation of CtBP1 and Sox2 and clinic pathological data of LADC patients and the survial ratio of LADC patients.2.Immunoprecipitation and immunohistochemostry analysis were performed to verify the interaction of CtBP1 and Sox23.Knockdown of expression of CtBPl or Sox2 in A549 cell,Western Blot analysis and RT-PCR methods were used to detect the levels of CtBP1 or Sox2 respectively.The markers of EMT and EMT related transcription factors were evaluated by Western blot and qRT-PCR methods,wound-healing assays and transwell assays were performed to show change of LADC cell migration and invasion,at the same time,MTT and Annexin V/P1 methods were used to analyze the proliferation and apoptosis ratio.4.The lung cancer PDTX nude mice was injected with Sox2 virus or CtBPl virus.The tumor volumes and tumor growth inhibition ratio were dected once one week.Results1.Immunohistochemistry analysis showed that the expression of CtBP1 and Sox2 in tumor tissues with metastasis were higher than that in tumor tissues without metastasis,and both were correlated with histological grade,lymph nodes metastases.And patients with high expression of CtBPl and Sox2 was related to a poor survival with statistical significance.2.CtBP1 interacts with Sox2 in LADC tissues and LADC cell in vitro.3.The silence of CtBPl or Sox2 was accompanied by the upregulation of epithelial marker E-cadherin and downregulation of mesenchymal marker N-cadherin.And downregulation of CtBPl or Sox2 could inhibit LADC cell proliferation,invasion and migration.4.In vivo,silencing expression of Sox2 or CtBP1 inhibited the tumor volumes of PDTX xenograft mice compared with NS group.Conclusions1.CtBPl and Sox2 were an independent prognostic indicator of overall survival.These data revealed that CtBPl and Sox2 may play a role in the oncogenesis and development of LADC and may be a new prognostic marker for LADC2.Sox2 interacts with CtBPl in LADC cells.3.downregulation of CtBPl or Sox2 both promotes LADC cell migration,invasion and proliferation and affects the expression of EMT marker in vitro.Meanwhile,Sox2 and CtBPl silence could inhibit the growth of tumor in vivo.4.These results indicate that Sox2-CtBP1-EMT may be a potential target for treating LADC.