Suppression of NF-kappa B survival signaling by nitrosylcobalamin sensitizes neoplasms to the anti-tumor effects of Apo2L/TRAIL.
We have previously demonstrated the anti-tumor activity of nitrosylcobalamin (NO-Cbl), an analog of vitamin B12 that delivers nitric oxide (NO) and increases the expression of tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) and its receptors in human tumors. The specific aim of this study was to examine whether NO-Cbl could sensitize drug-resistant melanomas to Apo2L/TRAIL. Antiproliferative effects of NO-Cbl and Apo2L/TRAIL were assessed in malignant melanomas and non-tumorigenic melanocyte and fibroblast cell lines. Athymic nude mice bearing human melanoma A375 xenografts were treated with NO-Cbl and Apo2L/TRAIL. Apoptosis was measured by TUNEL and confirmed by examining levels and activity of key mediators of apoptosis. The activation status of NF-kappa B was established by assaying DNA binding, luciferase reporter activity, the phosphorylation status of I kappa B alpha, and in vitro IKK activity. NO-Cbl sensitized Apo2L/TRAIL-resistant melanoma cell lines to growth inhibition by Apo2L/TRAIL but had minimal effect on normal cell lines. NO-Cbl and Apo2L/TRAIL exerted synergistic anti-tumor activity against A375 xenografts. Treatment with NO-Cbl followed by Apo2L/TRAIL induced apoptosis in Apo2L/TRAIL-resistant tumor cells, characterized by cleavage of caspase-3, caspase-8, and PARP. NO-Cbl inhibited IKK activation, characterized by decreased phosphorylation of I kappa B alpha and inhibition of NF-kappa B DNA binding activity. NO-Cbl suppressed Apo2L/TRAIL- and TNF-alpha-mediated activation of a transfected NF-kappa B-driven luciferase reporter. XIAP, an inhibitor of apoptosis, was inactivated by NO-Cbl. NO-Cbl treatment rendered Apo2L/TRAIL-resistant malignancies sensitive to the anti-tumor effects of Apo2L/TRAIL in vitro and in vivo. The use of NO-Cbl and Apo2L/TRAIL capitalizes on the tumor-specific properties of both agents and represents a promising anti-cancer combination.
Chawla-Sarkar
Mamta
M
Taussig Cancer Center, Center for Cancer Drug Discovery and Development, The Cleveland Clinic Foundation, Ohio 44195, USA.
Bauer
Joseph A
JA
Lupica
Joseph A
JA
Morrison
Bei H
BH
Tang
Zhuo
Z
Oates
Rhonda K
RK
Almasan
Alex
A
DiDonato
Joseph A
JA
Borden
Ernest C
EC
Lindner
Daniel J
DJ
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D051550:I-kappa B Kinase; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D051379:Mice; D008819:Mice, Nude; D016328:NF-kappa B / Q000378:metabolism*; D009368:Neoplasm Transplantation; D009603:Nitroso Compounds / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D015398:Signal Transduction / Q000187:drug effects; D053221:TNF-Related Apoptosis-Inducing Ligand; D014183:Transplantation, Heterologous; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014805:Vitamin B 12 / Q000031:analogs & derivatives* / Q000494:pharmacology*
D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D004273:DNA, Neoplasm; D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D009603:Nitroso Compounds; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; C113298:nitrosylcobalamin; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse; D014805:Vitamin B 12