Targeting a Newly Established Spontaneous Feline Fibrosarcoma Cell Line by Gene Transfer

Fibrosarcoma is a deadly disease in cats and is significantly more often located at classical vaccine injections sites. More rare forms of spontaneous non-vaccination site (NSV) fibrosarcomas have been described and have been found associated to genetic alterations. Purpose of this study was to compare the efficacy of adenoviral gene transfer in NVS fibrosarcoma. We isolated and characterized a NVS fibrosarcoma cell line (Cocca-6A) from a spontaneous fibrosarcoma that occurred in a domestic calico cat. The feline cells were karyotyped and their chromosome number was counted using a Giemsa staining. Adenoviral gene transfer was verified by western blot analysis. Flow cytometry assay and Annexin-V were used to study cell-cycle changes and cell death of transduced cells. Cocca-6A fibrosarcoma cells were morphologically and cytogenetically characterized. Giemsa block staining of metaphase spreads of the Cocca-6A cells showed deletion of one of the E1 chromosomes, where feline p53 maps. Semi-quantitative PCR demonstrated reduction of p53 genomic DNA in the Cocca-6A cells. Adenoviral gene transfer determined a remarkable effect on the viability and growth of the Cocca-6A cells following single transduction with adenoviruses carrying Mda-7/IL-24 or IFN-γ or various combination of RB/p105, Ras-DN, IFN-γ, and Mda-7 gene transfer. Therapy for feline fibrosarcomas is often insufficient for long lasting tumor eradication. More gene transfer studies should be conducted in order to understand if these viral vectors could be applicable regardless the origin (spontaneous vs. vaccine induced) of feline fibrosarcomas

Impact of rheology on the mass transfer coefficient during the growth phase of Trichoderma reesei in stirred bioreactors

Submerged cultures of filamentous fungi are widely used in industry to produce a variety of economically important proteins, such as cellulase enzymes. One of the possible strategies to increase enzyme yields relies on enhancing biomass concentration before production. However, when biomass concentration is increased, the culture broth becomes highly shear-thinning, affecting both mixing and oxygen transfer. Fungi and enzyme yields depend strongly on the ability to supply oxygen to the broth and, in consequence, scale-up considerations mainly focus on gas-liquid mass transfer predictions. In this study, rheology and mass transfer are characterised during the growth of Trichoderma reesei. A power law model is proposed to simulate the rheology of the broth, based on a consistency index that depends on the concentration of the biomass. Mass transfer coefficients measured during the growth phase in bioreactors of 3 and 20 L are compared to those measured with water and model fluids. As the value of power consumption is important for the mass transfer correlations, special care was devoted to validating its measurement in the larger vessel. Comparisons between experiments and recently developed correlations showed that the use of model fluids is a good way to investigate hydrodynamics and mass transfer inside large mock-ups. Good agreement was observed between mass transfer coefficients measured during the growth phase and those calculated using a correlation developed from model fluid experiments (Gabelle et al., 2011). The tools established here to estimate rheology and mass transfer during the T. reesei growth phase could be used in the future for cost estimation and process optimisation. (C) 2012 Elsevier Ltd. All rights reserved