A serotype 5/3 adenovirus expressing MDA-7/IL-24 infects renal carcinoma cells and promotes toxicity of agents that increase ROS and ceramide levels.
Agents that generate reactive oxygen species (ROS) are recognized to enhance MDA-7/IL-24 lethality. The present studies focused on clarifying how such agents enhanced MDA-7/IL-24 toxicity in renal cell carcinoma cells (RCCs). Infection of RCCs with a tropism-modified serotype 5/3 adenovirus expressing MDA-7/IL-24 (Ad.5/3-mda-7) caused plasma membrane clustering of CD95 and CD95 association with pro-caspase 8, effects that were enhanced by combined exposure to 17-N-allylamino-17-demethoxygeldanamycin (17AAG), As(2)O(3), or fenretinide and that correlated with enhanced cell killing. Knockdown of CD95 or expression of cellular FADD (Fas-associated protein with death domain)-like interleukin-1β-converting enzyme inhibitory protein, short form (c-FLIP-s) blocked enhanced killing. Inhibition of ROS generation, elevated cytosolic Ca(2+), or de novo ceramide synthesis blocked Ad.5/3-mda-7 ± agent-induced CD95 activation and the enhancement of apoptosis. Ad.5/3-mda-7 increased ceramide levels in a PERK-dependent fashion that were responsible for elevated cytosolic Ca(2+) levels that promoted ROS generation; 17AAG did not further enhance cytokine-induced ceramide generation. In vivo, infection of RCC tumors with Ad.5/3-mda-7 suppressed the growth of infected tumors that was enhanced by exposure to 17AAG. Our data indicate that in RCCs, Ad.5/3-mda-7-induced ceramide generation plays a central role in tumor cell killing and inhibition of multiple signaling pathways may have utility in promoting MDA-7/IL-24 lethality in renal cancer.
Department of Neurosurgery, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298-0035, USA.
Margaret A
MA
Park
Hossein A
HA
Hamed
Clint
C
Mitchell
Nichola
N
Cruickshanks
Rupesh
R
Dash
Jeremy
J
Allegood
Igor P
IP
Dmitriev
Gary
G
Tye
Besim
B
Ogretmen
Sarah
S
Spiegel
Adly
A
Yacoub
Steven
S
Grant
David T
DT
Curiel
Paul B
PB
Fisher
Paul
P
Dent
D000256:Adenoviridae / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology; D016227:Benzoquinones / Q000494:pharmacology; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000378:metabolism / Q000821:virology*; D045744:Cell Line, Tumor; D002518:Ceramides / Q000032:analysis / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis* / Q000378:metabolism / Q000502:physiology; D007680:Kidney Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000821:virology*; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D051379:Mice; D008819:Mice, Nude; D010087:Oxides / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism*; D014162:Transfection; D000099180:Interleukin-24
D000077237:Arsenic Trioxide; D001152:Arsenicals; D016227:Benzoquinones; D002518:Ceramides; D007378:Interleukins; D047029:Lactams, Macrocyclic; D010087:Oxides; D017382:Reactive Oxygen Species; D000099180:Interleukin-24; C112765:tanespimycin