Differential cellular responses induced by dorsomorphin and LDN-193189 in chemotherapy-sensitive and chemotherapy- resistant human epithelial ovarian cancer cells Jennifer L. Ali 1 , Brittany J. Lagasse 1 , Ainsley J. Minuk 1 , Allison J. Love 1 , Amani I. Moraya 1 , Linda Lam 1 , Gilbert Arthur 1 , Spencer B. Gibson 1,2,3 , Ludivine Coudie `re Morrison 1 , Tamra E. Werbowetski-Ogilvie 1 , Yangxin Fu 4 and Mark W. Nachtigal 1,3,5 1 Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada 2 Department of Immunology, University of Manitoba, Winnipeg, MB, Canada 3 Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, Canada 4 Department of Oncology, University of Alberta, Edmonton, AB, Canada 5 Department of Obstetrics, Gynecology and Reproductive Sciences, University of Manitoba, Winnipeg, MB, Canada Inherent or acquired drug resistance is a major contributor to epithelial ovarian cancer (EOC) mortality. Novel drugs or drug combinations that produce EOC cell death or resensitize drug resistant cells to standard chemotherapy may improve patient treatment. After conducting drug tolerability studies for the multikinase inhibitors dorsomorphin (DM) and it is structural ana- logue LDN-193189 (LDN), these drugs were tested in a mouse intraperitoneal xenograft model of EOC. DM significantly increased survival, whereas LDN showed a trend toward increased survival. In vitro experiments using cisplatin (CP)-resistant EOC cell lines, A2780-cp or SKOV3, we determined that pretreatment or cotreatment with DM or LDN resensitized cells to the killing effect of CP or carboplatin (CB). DM was capable of blocking EOC cell cycle and migration, whereas LDN produced a less pronounced effect on cell cycle and no effect on migration. Subsequent analyses using primary human EOC cell samples or additional established EOC cells lines showed that DM or LDN induced a dose-dependent autophagic or cell death response, respectively. DM induced a characteristic morphological change with the appearance of numerous LC3B-containing acidic vacuoles and an increase in LC3BII levels. This was coincident with a decrease in cell growth and the altered cell cycle consistent with DM-induced cytostasis. By contrast, LDN produced a caspase 3-independent, reactive oxygen species- dependent cell death. Overall, DM and LDN possess drug characteristics suitable for adjuvant agents used to treat chemotherapy-sensitive and -resistant EOC. Key words: epithelial ovarian cancer, drug resistance, autophagy, reactive oxygen species, dorsomorphin analogues, mouse xenograft Abbreviations: 7-AAD: 7-amino actinomycin D; AKT: protein kinase B; ALK: activin-like kinase; AMPK: adenosine monophosphate- activated protein kinase; AO: acridine orange; AraA: adenine 9-b-D-arabinofuranoside; Bcl: B-cell lymphoma; BMP: bone morphogenetic protein; BrdU: bromo-deoxy-uridine; CB: carboplatin; CP: cisplatin; CQ: chloroquine; DM: dorsomorphin; DMSO: dimethyl sulfoxide; EB: ethidium bromide; EOC: epithelial ovarian cancer; i.p.: intraperitoneal; LAP: transforming growth factor beta latency associated fac- tor; LC3: microtubule-associated protein 1A/1B-light chain 3; LDN: LDN-193189; MAPK: mitogen-activated protein kinase; MTS: [3- (4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium]; mTOR: mammalian target of rapamycin; NAC: n-acetylcysteine; PARP: poly (ADP-ribose) polymerase; PI3K: phosphatidylinositol 3-kinase; ROS: reactive oxygen species; Ser: serine; TUNEL: terminal deoxynucleotidyl transferase dUTP nick end labeling; VEGF: Vascular endothelial growth factor Additional Supporting Information may be found in the online version of this article. Grant sponsors: Manitoba Health Research Council (Establishment and Operating grants), University of Manitoba Research Grant Program, the Marsha Rivkin Center for Ovarian Cancer Research, and funds from the University of Manitoba Faculty of Medicine (M.W.N.); Grant sponsor: University of Manitoba (Undergraduate Research Award; A.J.L.); Grant sponsor: Saudi Arabian Cultural Bureau (Canada; A.I.M); Grant sponsor: University of Manitoba (Undergraduate Research Award program; L.L.); Grant sponsor: Women and Children’s Health Institute (WCHRI; start-up funds; Y.F.); Grant sponsor: Royal Alexandra Hospital Foundation (RAHF, Y.F.); Grant sponsor: Canada Research Chair Tier II program (T.E.W.) DOI: 10.1002/ijc.29220 History: Received 15 May 2014; Accepted 10 Sep 2014; Online 16 Sep 2014 Correpondence to: Mark Nachtigal, Department of Biochemistry and Medical Genetics, University of Manitoba, Room 333 BMSB, 745 Bannatyne Avenue, Winnipeg, Manitoba, Canada, R3E 0W9, Tel.: 1 204 789 3708, Fax: 1 204 789 3900, E-mail: mark.nachtigal@med.umanitoba.ca Cancer Therapy Int. J. Cancer: 136, E455–E469 (2015) V C 2014 UICC International Journal of Cancer IJC