title: Naphtho[1,2-b]furan-4,5-dione induces apoptosis of oral squamous cell carcinoma: involvement of EGF receptor/PI3K/Akt signaling pathway.
abstract: Naphtho[1,2-b]furan-4,5-dione (NFD), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exerts an anti-tumor effect. This study was performed to elucidate whether the epidermal growth factor (EGF) receptor and phosphatidylinositol-3-kinase (PI3K) signaling pathways are involved in NFD-induced apoptosis of oral squamous cell carcinoma (OSCC). Immunoblot showed that NFD suppressed the phosphorylation of EGF receptor and activation of PI3K/Akt, downstream molecules of EGF receptor signaling pathway, in Ca9-22 cells. The levels of downstream targets of Akt, including phospho-glycogen synthase kinase-3beta (p-GSK-3beta), GSK-3beta, forkhead transcription factor (FKHR), and cyclin D1, were also reduced after NFD treatment. Moreover, inactivation of nuclear factor-kappaB (NF kappaB), modulation of I kappa K beta and I kappaB alpha, up-regulation of Bad, and down-regulation of anti-apoptotic proteins including phospho-Bad, Bcl-X(L), myeloid cell leukemia-1(Mcl-1), and XIAP were found in NFD-treated cells. In addition, NFD treatment disrupted mitochondrial membrane potential (Delta Psi m), resulted in release of cytochrome c, and activation of both caspases-9 and caspase-3. Taken together, these results indicate that NFD induces apoptosis in Ca9-22 cells via inactivation of the EGF receptor-mediated survival pathway.
authors.affiliation: Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC.
authors.forename: Ching-Ming
authors.initials: CM
authors.lastname: Chien
authors.forename: Kuei-Li
authors.initials: KL
authors.lastname: Lin
authors.forename: Jung-Chen
authors.initials: JC
authors.lastname: Su
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Chuang
authors.forename: Chih-Hua
authors.initials: CH
authors.lastname: Tseng
authors.forename: Yeh-Long
authors.initials: YL
authors.lastname: Chen
authors.forename: Long-Sen
authors.initials: LS
authors.lastname: Chang
authors.forename: Shinne-Ren
authors.initials: SR
authors.lastname: Lin
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology*; D016328:NF-kappa B / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D051034:Inhibitor of Apoptosis Proteins; D016328:NF-kappa B; D009285:Naphthoquinones; C073873:naphtho(1,2-b)furan-4,5-dione; D045304:Cytochromes c; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt