KIF15, a key regulator of nasopharyngeal carcinoma development mediated by the P53 pathway

Background:Kinesin family member 15(KIF15)is a protein that regulates cell mitosis and plays an important role in the development and progression of several types of human cancers.However,the role of KIF15 in the development of nasopharyngeal cancer(NPC)is still unclear.Methods:The differential expression of KIF15 in NPC and para-carcinoma tissues was evaluated based on data collected from Gene Expression Omnibus(GEO)database and immunohistochemical analysis of clinical specimens collected from a patient cohort.Cell lines 5-8F and CNE-2Z were selected for the construction of KIF15‑knockdown cell models.CCK8 assay,flow cytometry,wound healing,Transwell and clone formation assays were used to detect the proliferation,apoptosis,migration,invasion and colony formation of NPC cells in vitro.A mouse xenograft model and the tail intravenous mouse distant transfer model were constructed for in vivo study.Furthermore,the potential molecular mechanisms underlying the effects of KIF15 were explored through western blot analysis,and several in vitro and in vivo functional assays were performed to explore its role in NPC.Results:The results revealed significantly higher expression of KIF15 in NPC tissues compared to para-carcinoma tissues.High levels of KIF15 expression were also associated with short overall survival(OS)and progression-free survival(PFS).Knockdown of the KIF15 gene led to a cell cycle arrest in the growth 2(G2)phase,inhibition of cell proliferation,migration,invasion,colony formation,and enhanced cell apoptosis.The in vivo murine xenograft experiments showed that down-regulation of the KIF15 gene could inhibit tumor growth and reduce the risk of liver and lung metastasis in NPC.Moreover,the evaluation of the molecular pathway showed that the mitogen-activated protein kinase/P53 pathways might be involved in the KIF15-induced regulation of NPC.Rescue assays indicated that Pifithrin-αcould counteract the pro-proliferative and pro-apoptotic effects mediated by KIF15.Conclusion:This work indicated that KIF15 overexpression accelerated the progression of NPC and promoted the development of distant metastases.Therefore,KIF15 may have an important role as a prognostic indicator and a potential drug target for the treatment of NPC.

ZBTB7A governs 2-DG-inhibited glycolysis by regulating GLUT1 in nasopharyngeal carcinoma

Our previous studies suggested a potential interaction between the POK erythroid myeloid ontogenic factor ZBTB7A and glucose transporter 1(GLUT1)in nasopharyngeal carcinoma(NPC).This study was designed to confirm the interaction and further evaluate the precise mechanism by which ZBTB7A and GLUT1 regulate NPC development.The binding sites between ZBTB7A and the promoter of GLUT1 were predicted by bioinformatics.Gene expression was measured by quantitative real-time polymerase chain reaction(qPCR),western blotting,and immunohistochemistry.The activities of key glycolysis enzymes,including hexokinase(HK),pyruvate kinase(PK),lactate dehydrogenase(LDH),and lactate,were detected using specific enzyme-linked immunosorbent assay kits.The connection between ZBTB7A and GLUT1 was analyzed by dual-luciferase reporter assay and chromatin immunoprecipitation-qPCR.The vitality,proliferation,and tumorigenicity of the cells expressing different levels of ZBTB7A were tested by adding the glycolysis inhibitor 2-deoxy-D-glucose(2-DG),followed by MTT,colorimetric focus forming,and xenograft assays,respectively.Our results showed that high expression of GLUT1 was associated with late-stage NPC.After constructing stably transfected cells with lentiviruses,ZBTB7A was effectively knocked down in 5-8F cells(RNAi-5-8F)and overexpressed in 6-10B cells(ZBTB7A-6-10B).The up-or downregulation of GLUT1 secondary to ZBTB7A changes was also limited.The vitality and proliferation of the cells expressing low ZBTB7A were notably blocked by 2-DG.The cells expressing high ZBTB7A were not very sensitive to 2-DG.The growth of RNAi-5-8F xenografts was strongly suppressed by 2-DG.The activities of HK,PK,and LDH were suppressed by 2-DG in the cells expressing low ZBTB7A.RNAi-5-8F cells had the lowest 2-DG-induced lactate production.ZBTB7A directly suppressed the promoter region of GLUT1 to regulate GLUT1 expression.Thus,ZBTB7A controls the 2-DG-induced inhibition of glycolysis by affecting GLUT1.