Advances in treatment of mesothelioma.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is an uncommon, aggressive cancer, derived from pleural mesothelial cells, that has a close relationship to asbestos exposure. To date, MPM prognosis is poor and very few treatment options are available for both localized and advanced MPM. AREAS COVERED: The standard of care is still chemotherapy with platinum derivates and antifolate agents. In the last few years, several new agents have been studied on the basis of mesothelioma carcinogenesis and invasiveness mechanisms; however, the recent results are poor and few drugs have been tested in phase III trials because of toxicity or because they did not improve patient outcomes. The aim of this review is to focus on the current available treatment for MPM through the analysis of the results comes from the phase III trials and to discuss the future perspectives in the pathogenesis, diagnosis and treatment. EXPERT OPINION: Many compounds are currently under investigation in different subsets of patients. Interesting data have come from preliminary studies on immunotherapy, but randomized studies are needed to confirm the preliminary positive results of this new strategy. A better comprehension of MPM pathogenesis should be obtained to improve and develop new diagnostic tools and target therapies.

IGF-IR-dependent expression of Survivin is required for T-antigen-mediated protection from apoptosis and proliferation of neural progenitors.

The insulin-like growth factor-1 receptor (IGF-IR) and the human polyomavirus JCV protein, T-antigen cooperate in the transformation of neuronal precursors in the cerebellum, which may be a contributing factor in the development of brain tumors. Because it is not clear why T-antigen requires IGF-IR for transformation, we investigated this process in neural progenitors from IGF-IR knockout embryos (ko-IGF-IR) and from their wild-type nontransgenic littermates (wt-IGF-IR). In contrast to wt-IGF-IR, the brain and dorsal root ganglia of ko-IGF-IR embryos showed low levels of the antiapoptotic protein Survivin, accompanied by elevated numbers of apoptotic neurons and an earlier differentiation phenotype. In wt-IGF-IR neural progenitors in vitro, induction of T-antigen expression tripled the expression of Survivin and accelerated cell proliferation. In ko-IGF-IR progenitors induction of T-antigen failed to increase Survivin, resulting in massive apoptosis. Importantly, ectopic expression of Survivin protected ko-IGF-IR progenitor cells from apoptosis and siRNA inhibition of Survivin activated apoptosis in wt-IGF-IR progenitors expressing T-antigen. Our results indicate that reactivation of the antiapoptotic Survivin may be a critical step in JCV T-antigen-induced transformation, which in neural progenitors requires IGF-IR.