Production of human epidermal growth factor in cell suspension cultures of Centella asiatica (L.) Urban using balloon-type bubble bioreactors

Human epidermal growth factor (hEGF) has several medicinal and pharmacological applications. The aim of this study was to determine whether callus and cell suspension cultures of the medicinal plant Centella asiatica could produce hEGF. The callus of C. asiatica was transformed using Agrobacterium tumefaciens strains carrying the hEGF and hEGF-KDEL (KDEL sequence targeting peptides to endoplasmic reticulum) genes on plasmids pKRE1 and pKRE2, respectively, under the control of 35S promoters. Polymerase chain reaction (PCR) was performed using gene-specific primers to select transformed callus lines. Quantitative reverse transcription- PCR and western blotting were performed to confirm that EGF was expressed in the transformed lines. Cell suspension cultures were established in balloon-type bubble bioreactors using transformed EK2 cells. Efficiently transformed cell biomass was produced in bioreactor cultivation. The hEGF protein isolated from transformed cells induced the in vitro cell proliferation of human keratinocytes (HaCaT cells). Therefore, plant expression systems, particularly plant cell cultures, can produce recombinant hEGF.