Synergistic cytotoxicity of interferonalpha-2b and interleukin-2 in combination with PBMC against ovarian cancer: development of an experimental model for cellular therapy.
OBJECTIVE
Current therapies for ovarian cancer (OC) patients have a modest impact on long-term survival justifying the need for novel treatment strategies. We developed in vitro and in vivo systems to test the effects of cytokines in combination with peripheral blood mononuclear cells (PBMC) on OC cells.


METHODS
Two OC cell-lines were transfected with a plasmid encoding Red Fluorescent Protein (SKOV3-RFP and CAR3-RFP). Proliferation of these lines in the presence of cytokines alone and in combination was assayed. Cytotoxicity of SKOV3-RFP cells mediated by PBMC and cytokines was determined by lactate dehydrogenase release. Mice were injected intraperitoneally (IP) with SKOV3-RFP cells; solid tumor and ascitic fluid were collected, analyzed, and cell lines were established. Tumor-derived cell lines were re-injected to produce a more tumorigenic line.


RESULTS
IFNalpha-2b showed an inhibitory effect on OC cell proliferation. The remaining cytokines, either alone or in combination, showed no significant effect. PBMC in combination with IL-2 showed clear dose-dependent cytotoxicity against SKOV3-RFP. IFNalpha-2b had a synergistic effect with IL-2 and PBMC increasing the cytotoxicity by an average of 20%. Using an animal model, SKOV3-RFP cells continue to express RFP when harvested from the peritoneum and are more tumorigenic when re-injected into mice.


CONCLUSIONS
These observations justify the use of IL-2, IFNalpha-2b, and PBMC in a xenograph animal model of OC to determine if combination cytokine and cellular therapy has an anti-tumor effect in vivo. This approach may prove useful as an in vivo system of IP cytokines administered in combination with cellular therapy.
Ingersoll
Susan B
SB
Cellular Therapy Laboratory, Florida Hospital Cancer Institute, Orlando, FL 32804, USA. susan.blaydes@flhosp.org
Patel
Sheylan
S
Caballero
Lizette
L
Ahmad
Sarfraz
S
Edwards
Dawn
D
Holloway
Robert W
RW
Edwards
John R
JR
D000818:Animals; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D004357:Drug Synergism; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D051379:Mice; D008819:Mice, Nude; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000276:immunology / Q000628:therapy*; D011994:Recombinant Proteins; D023041:Xenograft Model Antitumor Assays
D000077190:Interferon alpha-2; D016898:Interferon-alpha; D007376:Interleukin-2; D011994:Recombinant Proteins