title: p16 Protein and gigaxonin are associated with the ubiquitination of NFκB in cisplatin-induced senescence of cancer cells.
abstract: The molecular mechanism of p16-mediated senescence in cisplatin-treated cancer cells is not fully understood. Here we show that cisplatin treatment of head and neck cancer cells results in nuclear transport of p16 leading to a molecular modification of NFκB. Chromatin immunoprecipitation assays show that this modification is associated with the inhibition of NFκB interacting with its DNA binding sequences, leading to decreased expression of NFκB-transcribed proteins. LCMS proteomic analysis of LAP-TAP-purified proteins from HeLa cells containing a tetracycline-inducible GFP-S peptide-NFκB expression system identified gigaxonin, an ubiquitin E3 ligase adaptor, as an NFκB-interacting protein. Immunoblotting and siRNA studies confirmed the NFκB-gigaxonin interaction and the dependence of this binding on p16-NFκB binding. Using gel shift assays, we have confirmed p16-NFκB and gigaxonin-NFκB interactions. Furthermore, we have observed increased NFκB ubiquitination with cisplatin treatment that is abolished in the absence of p16 and gigaxonin expression. Analysis of 103 primary tumors has shown that increased nuclear p16 expression correlates with enhanced survival of head and neck cancer patients (p < 0.0000542), indicating the importance of nuclear p16 expression in prognosis. Finally, p16 expression is associated with reduced cytokine expression and the presence of human papilloma virus in chemoradiation-sensitive basaloid tumors. However, the absence of p16 expression is associated with enhanced cytokine expression and the absence of human papilloma virus in aggressive tumors. These results clearly demonstrate that nuclear p16 and gigaxonin play an important role in chemosensitivity of head and neck cancers through ubiquitination of NFκB.
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Mysore S
authors.initials: MS
authors.lastname: Veena
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Reason
authors.initials: R
authors.lastname: Wilken
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Zheng
authors.affiliation: Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095.
authors.forename: Ankur
authors.initials: A
authors.lastname: Gholkar
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Venkatesan
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073, Department of Head and Neck Surgery, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095.
authors.forename: Darshni
authors.initials: D
authors.lastname: Vira
authors.affiliation: Department of Head and Neck Surgery, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095.
authors.forename: Sameer
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Saroj K
authors.initials: SK
authors.lastname: Basak
authors.affiliation: Departments of Anatomy, Physiology, and Genetics, Uniformed Services University, Bethesda, Maryland 20814.
authors.forename: Clifton L
authors.initials: CL
authors.lastname: Dalgard
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073.
authors.forename: Sandhiya
authors.initials: S
authors.lastname: Ravichandran
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073, Department of Medicine and Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095.
authors.forename: Raj K
authors.initials: RK
authors.lastname: Batra
authors.affiliation: Department of Medicine and.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Kasahara
authors.affiliation: Department of Medicine and.
authors.forename: David
authors.initials: D
authors.lastname: Elashoff
authors.affiliation: Pathology and Laboratory Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fishbein
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, UCLA, Los Angeles, California 90095, and.
authors.forename: Julian P
authors.initials: JP
authors.lastname: Whitelegge
authors.affiliation: Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095.
authors.forename: Jorge Z
authors.initials: JZ
authors.lastname: Torres
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073, Department of Head and Neck Surgery, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095.
authors.forename: Marilene B
authors.initials: MB
authors.lastname: Wang
authors.affiliation: From the Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System/David Geffen School of Medicine at UCLA, Los Angeles, California 90073, Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095 esrivats@ucla.edu.
authors.forename: Eri S
authors.initials: ES
authors.lastname: Srivatsan
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D016922:Cellular Senescence / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology*; D019938:Cyclin D1 / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology / Q000821:virology; D052162:Human papillomavirus 16 / Q000502:physiology; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D011379:Prognosis; D054875:Ubiquitination / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D019941:Cyclin-Dependent Kinase Inhibitor p16; D003598:Cytoskeletal Proteins; C416508:GAN protein, human; D016328:NF-kappa B; D019938:Cyclin D1; D002945:Cisplatin
keywords: Cancer Stem Cells; Cellular Senescence; Chemoresistance; Cisplatin; Gigaxonin; Head and Neck Cancer; NFκB; Ubiquitination; p16 Suppressor Gene