RESUMEN
Numerous studies have attempted to restore the function of the tumour suppressor p53 as an anti-cancer strategy through gene delivery. However, most studies employed non-bacterial vectors to deliver p53. Various facultative and obligate anaerobic bacteria have been proposed as vectors because of their intrinsic tumour targeting ability and anti-tumour activity. Salmonella enterica Typhimurium is the most studied bacterial vector in anti-cancer therapy. We used the previously designed χ11218 strain of S. enterica Typhimurium, displaying regulated delayed lysis, as a vector for delivering p53 to human bladder carcinoma cells, restoring wild-type p53 protein function. We cloned p53 into pYA4545 (containing a eukaryotic expression system) to generate the χ11218 pYA4545p53 strain. Cloning of p53 did not affect the growth or interfere with the invasive and replicative capacity of χ11218 bacteria in tumour cells. Human bladder carcinoma cells (expressing mutated p53) transfected with pYA4545p53 showed a significant increase in the expression of p53 protein. We demonstrated that p53 supplied by χ11218 significantly decreased the viability of human bladder cancer cells in a dose-dependent manner. This study demonstrates the applicability of the attenuated χ11218 strain as a vector for DNA plasmids expressing tumour suppressor genes.
Asunto(s)
Carcinoma , Neoplasias de la Vejiga Urinaria , Carcinoma/genética , Muerte Celular , Genes p53 , Humanos , Salmonella typhimurium/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Vejiga Urinaria , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/terapiaRESUMEN
The bovine papillomavirus (BPV) causes papillomas that regress spontaneously, but can also progress to malignancy. This study evaluated the role of BPV in oncogenesis. Twenty-four samples from uninfected calves and the papillomas of BPV infected cattle were subjected to molecular diagnosis, as well as histopathological and immunohistochemical analyses. The comet assay (CA) was used to evaluate the clastogenic potential of BPV. The results confirmed the presence of BPV-2, 3, 5, and 9 in infected samples. Histopathological analysis revealed acanthosis, koilocytosis, hypergranulosis, hyperkeratosis, and transformed fibroblasts.E7 and L1 BPV proteins were detected in the epithelium, as well as in the connective tissues, indicating productive infection at different sites. CA results showed that BPV-2, 5, and 9 exhibit the same level of clastogenicity. These findings support the oncogenic action of BPV in establishing a favorable microenvironment for oncogenesis.
Asunto(s)
Enfermedades de los Bovinos/patología , Enfermedades de los Bovinos/virología , Papillomaviridae/genética , Infecciones por Papillomavirus/veterinaria , Animales , Papillomavirus Bovino 1/clasificación , Papillomavirus Bovino 1/genética , Carcinogénesis , Bovinos , Ensayo Cometa , ADN Viral/genética , Papillomaviridae/clasificación , Infecciones por Papillomavirus/patología , Infecciones por Papillomavirus/virologíaRESUMEN
This study diagnosed cutaneous wart lesions excised from three rams from a sheep farm in São Paulo State, Brazil. Histopathologically, these cases were diagnosed as papilloma. The amplification by PCR, sequencing and bioinformatics analysis showed that all the lesions presented DNA sequences of bovine papillomavirus type 2. This is the first report confirming the detection of BPV2 in papilloma warts from ovines.