title: Cisplatin enhances protein kinase R-like endoplasmic reticulum kinase- and CD95-dependent melanoma differentiation-associated gene-7/interleukin-24-induced killing in ovarian carcinoma cells.
abstract: Melanoma differentiation associated gene-7/interleukin 24 (mda-7/IL-24) is a unique interleukin (IL)-10 family cytokine displaying selective apoptosis-inducing activity in transformed cells without harming normal cells. The present studies focused on defining the mechanism(s) by which recombinant adenoviral delivery of MDA-7/IL-24 inhibits cell survival of human ovarian carcinoma cells. Expression of MDA-7/IL-24 induced phosphorylation of protein kinase R-like endoplasmic reticulum kinase (PERK) and eukaryotic initiation factor2alpha (eIF2alpha). In a PERK-dependent fashion, MDA-7/IL-24 reduced ERK1/2 and AKT phosphorylation and activated c-Jun NH(2)-terminal kinase (JNK) 1/2 and p38 mitogen-activated protein kinase (MAPK). MDA-7/IL-24 reduced MCL-1 and BCL-XL and increased BAX levels via PERK signaling; cell-killing was mediated via the intrinsic pathway, and cell killing was primarily necrotic as judged using Annexin V/propidium iodide staining. Inhibition of p38 MAPK and JNK1/2 abolished MDA-7/IL-24 toxicity and blocked BAX and BAK activation, whereas activation of mitogen-activated extracellular-regulated kinase (MEK) 1/2 or AKT suppressed enhanced killing and JNK1/2 activation. MEK1/2 signaling increased expression of the MDA-7/IL-24 and PERK chaperone BiP/78-kDa glucose regulated protein (GRP78), and overexpression of BiP/GRP78 suppressed MDA-7/IL-24 toxicity. MDA-7/IL-24-induced LC3-green fluorescent protein vesicularization and processing of LC3; and knockdown of ATG5 suppressed MDA-7/IL-24-mediated toxicity. MDA-7/IL-24 and cisplatin interacted in a greater than additive fashion to kill tumor cells that was dependent on a further elevation of JNK1/2 activity and recruitment of the extrinsic CD95 pathway. MDA-7/IL-24 toxicity was enhanced in a weak additive fashion by paclitaxel; paclitaxel enhanced MDA-7/IL-24 + cisplatin lethality in a greater than additive fashion via BAX. Collectively, our data demonstrate that MDA-7/IL-24 induces an endoplasmic reticulum stress response that activates multiple proapoptotic pathways, culminating in decreased ovarian tumor cell survival.
authors.affiliation: Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0035, USA.
authors.forename: Adly
authors.initials: A
authors.lastname: Yacoub
authors.forename: Renyan
authors.initials: R
authors.lastname: Liu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Park
authors.forename: Hossein A
authors.initials: HA
authors.lastname: Hamed
authors.forename: Rupesh
authors.initials: R
authors.lastname: Dash
authors.forename: Danielle N
authors.initials: DN
authors.lastname: Schramm
authors.forename: Devanand
authors.initials: D
authors.lastname: Sarkar
authors.forename: Igor P
authors.initials: IP
authors.lastname: Dimitriev
authors.forename: Jessica K
authors.initials: JK
authors.lastname: Bell
authors.forename: Steven
authors.initials: S
authors.lastname: Grant
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Farrell
authors.forename: David T
authors.initials: DT
authors.lastname: Curiel
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fisher
authors.forename: Paul
authors.initials: P
authors.lastname: Dent
mesh_terms: D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology* / Q000627:therapeutic use; D004357:Drug Synergism; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D005260:Female; D018014:Gene Transfer Techniques; D006801:Humans; D007378:Interleukins / Q000008:administration & dosage / Q000235:genetics / Q000502:physiology*; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D019892:eIF-2 Kinase / Q000378:metabolism*; D019014:fas Receptor / Q000378:metabolism*; D000099180:Interleukin-24
chemical_list: D002945:Cisplatin; D000091342:Endoplasmic Reticulum Chaperone BiP; D007378:Interleukins; D019892:eIF-2 Kinase; D019014:fas Receptor; D000099180:Interleukin-24; C000717247:HSPA5 protein, human