Preclinical study of an ex vivo gene therapy protocol for hepatocarcinoma.
Preclinical studies in several animal models as well as clinical trials have shown a reduction in tumor growth following immunotherapy with interleukin-12 (IL-12). This cytokine is appropriate to test in therapeutic clinical trials to treat hepatocarcinoma (HC), a pathology often associated with hepatitis B or C-induced cirrhosis. The local delivery into the liver would be achieved through ex vivo gene transfer using retroviral (rv) vectors in autologous fibroblast carriers. In support of this clinical trial, a rv vector has been constructed to express coordinately both chains p35 and p40 of human IL-12. Here, we have tested good manufacturing practices (GMP) clinical lots of viral vectors derived from the transfected packaging cell line, PG13rvIL-12. We have also devised methods to facilitate the isolation of fibroblasts from freshly harvested skin specimens, enhance their outgrowth in large-scale cultures and assay IL-12 production following transduction, without any selection and irradiation. Twenty-four human skin specimens were processed to obtain fibroblast suspensions that were typically maintained for up to 8 or 12 passages. The mean +/-s.d. overall time for obtaining the required number of transduced cells for the highest IL-12 need was 40 days. The procedure, in accordance with the French medical agency for gene therapy clinical trials, is now ready to begin a clinical trial.
Lortal
B
B
INSERM U563, CPTP, Institut Claudius Regaud, Toulouse, France.
Gross
F
F
Peron
J M
JM
Pénary
M
M
Berg
D
D
Hennebelle
I
I
Favre
G
G
Couderc
B
B
D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000628:therapy*; D018929:Cell Culture Techniques; D004353:Drug Evaluation, Preclinical; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D005720:Gamma Rays; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D053765:Interleukin-12 Subunit p35 / Q000096:biosynthesis / Q000235:genetics; D053762:Interleukin-12 Subunit p40 / Q000096:biosynthesis / Q000235:genetics; D008113:Liver Neoplasms / Q000235:genetics / Q000628:therapy*; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic
D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40