Glucose-methanol-based fed-batch fermentation for the production of recombinant human interferon gamma (rhIFN-gamma) and evaluation of its antitumor potential

Squamous cell carcinoma (SCC) is nonmelanoma skin cancer, which is very common in patients having T-cell immunosuppressant drugs. Anticancerous agents such as cytokines showed effective response on SCC. Human interferon-gamma (hIFN-gamma), a type II cytokines, are having potent antiproliferative and immunomodulatory effects. In the current study, the fed-batch cultivation of recombinant Pichia pastoris was carried out, and its effect on cell biomass production, recombinant human interferon-gamma (rhIFN-gamma) production, and the overflow metabolites was estimated. P. pastoris GS115 strain coexpressed with 6-phosphogluconolactonase (SOL3) and ribulose-phosphate 3-epimerase (RPE1) gene (GS115/rhIFN-gamma/SR) resulted in 60 mg L-1 of rhIFN-gamma production, which was twofold higher as compared with the production from GS115/rhIFN-gamma strain. The antiproliferative potential of rhIFN-gamma was examined on the human squamous carcinoma (A431) cell lines. Cells treated with 80 ng mL(-1) of rhIFN-gamma exhibited 50% growth inhibition by enhancing the production of intracellular reactive oxygen species levels and disrupting membrane integrity. Our findings highlight a state of art process development strategy for the high-level production of rhIFN-gamma and its potential application as a therapeutic drug in SCC therapy.