Regulation of apoptosis and cell proliferation by Sorafenib in Hepatocellular carcinoma

Motivation: Hepatocellular carcinoma (HCC), which represents more than 90% of primary liver cancers, is the sixth most common type of cancer with 749.000 new cases each year and the third cause of death associated with cancer. At early stages of HCC, the tumor might be cured by treatments as resection, ablation or liver transplantation. However, there are no effective therapies for patients with advanced HCC, who represents two thirds of diagnosed patients. In this context, Sorafenib, an oral multikinase inhibitor of some targets like Raf, VEGFR and PDGFR, among others, is the only therapeutic option in advanced HCC. Sorafenib has important actions inhibiting the cell proliferation and apoptosis in tumor hepatocytes, developing limited side effects but, more fundamentally, disease stabilization and increasing the survival rate to 9.2 months. The importance of this work is based on the lack of curative therapies in advanced HCC. Bearing in mind that illness is a major global health problem, is really important to carry out researches for finding new mechanisms, other targets and improvements of this drug in order to enhance the therapeutic options of patients, especially who suffer advanced HCC. Results: On the one hand, we find that Sorafenib decreases the Mcl-1 expression and increases the pMcl-1 (pSer159 + pThr193) leading to an increment of intrinsic apoptosis. In this context, not only does Sorafenib promote the activity of caspase-3 and caspasa-9, but also alters mitochondrial membrane potential in different HCC cell lines. On the other hand, Sorafenib decreases the cell proliferation. Taking into account all these results, Sorafenib has a relevant anti-tumor activity in in vitro studies.Conclusions: Sorafenib has an anti-tumor activity by activating cell death and blocking cell proliferation. The promotion of intrinsic apoptosis is due to the activation of caspase-3 and caspase-9 as well as inhibition the anti-apoptotic action of Mcl-1 and changes in the mitochondrial membrane potential

Translational pancreatic cancer research: A comparative study on patient-derived xenograft models.

To assess the viability of orthotopic and heterotopic patient-derived pancreatic cancer xenografts implanted into nude mice. This study presents a prospective experimental analytical follow-up of the development of tumours in mice upon implantation of human pancreatic adenocarcinoma samples. Specimens were obtained surgically from patients with a pathological diagnosis of pancreatic adenocarcinoma. Tumour samples from pancreatic cancer patients were transplanted into nude mice in three different locations (intraperitoneal, subcutaneous and pancreatic). Histological analysis (haematoxylin-eosin and Masson's trichrome staining) and immunohistochemical assessment of apoptosis (TUNEL), proliferation (Ki-67), angiogenesis (CD31) and fibrogenesis (α-SMA) were performed. When a tumour xenograft reached the target size, it was re-implanted in a new nude mouse. Three sequential tumour xenograft generations were generated (F1, F2 and F3). The overall tumour engraftment rate was 61.1%. The subcutaneous model was most effective in terms of tissue growth (69.9%), followed by intraperitoneal (57.6%) and pancreatic (55%) models. Tumour development was faster in the subcutaneous model (17.7 ± 2.6 wk) compared with the pancreatic (23.1 ± 2.3 wk) and intraperitoneal (25.0 ± 2.7 wk) models (P = 0.064). There was a progressive increase in the tumour engraftment rate over successive generations for all three models (F1 28.1% vs F2 71.4% vs F3 80.9%, P In our experience, the faster development and greatest number of viable xenografts could make the subcutaneous model the best option for experimentation in pancreatic cancer

Screening of effective pharmacological treatments for MELAS syndrome using yeasts, fibroblasts and cybrid models of the disease

Trabajo presentado como póster al 22nd IUBMB & 37th FEBS Congress, celebrado en Sevilla (España) del 4 al 9 de septiembre de 2012.[Backgroun and Purpose]: MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) is a mitochondrial disease most usually caused by point mutations in tRNA genes encoded by mitochondrial DNA (mtDNA). Approximately 80% of cases of MELAS syndrome are associated with a m.3243A > G mutation in the MT-TL1 gene, which encodes the mitochondrial tRNALeu (UUR). Currently, no effective treatments are available for this chronic progressive disorder. Treatment strategies in MELAS and other mitochondrial diseases consist of several drugs that diminish the deleterious effects of the abnormal respiratory chain function, reduce the presence of toxic agents or correct deficiencies in essential cofactors.[Experimental Approach]: We evaluated the effectiveness of some common pharmacological agents that have been utilized in the treatment of MELAS, in yeast, fibroblast and cybrid models of the disease. The yeast model harbouring the A14G mutation in the mitochondrial tRNALeu(UUR) gene, which is equivalent to the A3243G mutation in humans, was used in the initial screening. Next, the most effective drugs that were able to rescue the respiratory deficiency in MELAS yeast mutants were tested in fibroblasts and cybrid models of MELAS disease.[Key Results]: According to our results, supplementation with riboflavin or coenzyme Q10 effectively reversed the respiratory defect in MELAS yeast and improved the pathologic alterations in MELAS fibroblast and cybrid cell models.[Conclusions and Implications]: Our results indicate that cell models have great potential for screening and validating the effects of novel drug candidates for MELAS treatment and presumably also for other diseases with mitochondrial impairment.This work was supported by FIS PI10/00543 grant, FIS EC08/00076 grant, Ministerio de Sanidad, Spain and Fondo Europeo de Desarrollo Regional (FEDER-Unión Europea), SAS111242 grant, Servicio Andaluz de Salud-Junta de Andalucía, Proyecto de Investigación de Excelencia de la Junta de Andalucía CTS-5725, and by AEPMI (Asociación de Enfermos de Patología Mitocondrial), FEEL (Fundación Española de Enfermedades Lisosomales) and Federación Andaluza de Fibromialgia y Fatiga Crónica (ALBA Andalucía). MM receiveda fellowship from Colegio Oficial de Farmacéuticos de Sevilla. This group was founded by the Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER),ISCIII.Peer reviewe