The Effects Of MiR-196b And MiR-144-5p In Cell Proliferation,Metastasis And Apoptosis Of Lung Cancer

The first part: Micro RNA-196 b inhibits cell growth and metastasis of lung cancer cells by targeting Runx2Background /Aims: Lung cancer is one of the most common causes of cancer related deaths worldwide.The role of several micro RNAs(mi RNAs)including mi R-196 b in different cancers has already been established.The study was aimed to explore the role of mi R-196 b in lung cancer and its possible underlying mechanism.Methods: Human lung cancer cell line A549 was transfected with mi R-196 b mimic,mi R-196 b inhibitor and corresponding controls.Then cell viability,migration,invasion,and apoptosis of A549 lung cancer cells either with overexpression or with suppression of mi R-196 b were estimated sequentially.Next,dual luciferase activity assay was performed to clarify whether Runx2 was a direct target of mi R-196 b.Finally,the expressions of main factors associated with epithelial mesenchymal transition(EMT),PI3K/AKT/GSK3β,Smad,and JNK pathways were detected by Western blot.Results: Mi R-196 b expression was significantly decreased in A549,H1650 and H1299 cell lines compared with in WI-38 and HEL-1 cell lines.Overexpression of mi R-196 b suppressed cell viability,migration,invasion,and induced apoptosis as well as inhibited TGF-β induced EMT process in A549 cells.In addition,Runx2 was a putative target of mi R-196 b,and Runx2 silence remarkably increased cell apoptosis and abolished the promotive effects of mi R-196 b suppression on cell viability,migration and invasion.Finally,mi R-196 b also mediated its action by inactivation of PI3K/AKT/GSK3β,Smad,and JNK pathways by down-regulation of Runx2.Conclusion: Mi R-196 b functions as a tumor suppressor that inhibited cell growth and metastasis of lung cancer cells by targeting Runx2.These findings provided further evidences for treatment of lung cancer.The second part: Mi R-144-5p inhibits the proliferation and induces the apoptosis of non-small cell lung cancer cells by modulating RAB14 expressionBackground /Aims: Mounting evidence indicates that micro RNAs(mi RNAs or mi Rs)play a pivotal regulatory role in the initiation and progression of malignant neoplasms,including lung cancer.However,the impact of mi R-144-5p on the progression of tumors,especially lung cancer,remains poorly understood.In the present study,we aimed to explore the role of mi R-196 b in lung cancer and its possible underlying mechanism.Methods: Normal human airway epithelial 16-HBE cells and NSCLC cell lines(A549,H1299,H441,Calu-1,and Calu-3)were purchased from the American Type Culture Collection.A549 or H1299 was transfected with mi R-144-5p mimic,mi R-144-5p inhibitor and corresponding controls.Then cell viability,migration,invasion,and apoptosis of lung cancer cells either with overexpression or with suppression of mi R-144-5p were estimated sequentially.And tumor xenografts models of mice were established,then the tumor volume and weight were determined.Next,Western blot、q RT-PCR and dual luciferase activity assay was performed to clarify whether RAB14 was a direct target of mi R-144-5p.Results: mi R-144-5p expression was inversely correlated to the Ki67 index in the tumorous tissues and progression-free survival(PFS)in the NSCLC patients.In addition,in vitro studies revealed that restoration of mi R-144-5p expression inhibited the proliferation,migration,and invasion but promoted the apoptosis of NSCLC A549 and H1299 cells.Moreover,mi R-144-5p inhibited the colony formation of A549 and H1299 cells as well as the tumor growth of A549 cell xenografts in mice.Further studies validated that Ras-related protein 14(RAB14)was the direct target of mi R-144-5p as assessed by Western blot analysis,quantitative real-time polymerase chain reaction(q RT-PCR),and luciferase reporter assays.Knockdown of RAB14 inactivated the Akt pathway but also suppressed the proliferation,migration,and invasion of NSCLC cells as well as induced apoptosis.In addition,overexpression of RAB14 abrogated the antagonistic effects of mi R-144-5p on the progression of NSCLC cells in vitro and in vivo.Our findings demonstrate that mi R-144-5p regulates the progression of NSCLC cells through modulating RAB14 expression.Thus,targeting the mi R-144-5p/RAB14 axis might serve as a novel therapeutic strategy for NSCLC treatment.Conclusion: In summary,mi R-144-5p expression correlates with the clinical features of NSCLC patients and plays a tumor-suppressive role in NSCLC.RAB14 is a bona fide functional target of mi R-144-5p in NSCLC.Our findings suggest that the mi R-144-5p/RAB14 axis is a biomarker for the prognosis and treatment of NSCLC.