No abstract

Epithelial-mesenchymal transition is a physiopathological process by which epithelial cells acquire mesenchymal shape and properties. Malignant mesothelioma is histologically characterized by the concomitant presence of epithelioid and sarcomatoid features, the latter being associated to worse prognosis, thus suggesting a role of epithelial-mesenchymal transition in this dual phenotype. We studied 109 malignant mesotheliomas (58 epithelioid, 26 sarcomatoid, and 25 biphasic) by immunohistochemistry and qRT-PCR analysis, and demonstrated a substantial switch from epithelial markers (E-cadherin, b-catenin, and cytokeratins 5/6) to mesenchymal markers (N-cadherin, vimentin, a-smooth muscle actin, Snail, Slug, Twist, ZEB1, ZEB2, S100A4, MMP2, and MMP9) through epithelioid to biphasic and sarcomatoid histotypes. In agreement with these findings, the ectopic expression of miR-205 (a repressor of ZEB1 and ZEB2 expression) in MeT-5A (mesothelial cell line), H2452 (an epithelioid malignant mesothelioma cell line) and MSTO-211H (a biphasic malignant mesothelioma cell line) not only induced a significant reduction of ZEB1 and ZEB2 and a consequent up-regulation of E-cadherin gene expression, but also inhibited migration and invasion. Moreover, miR-205 was significantly down-regulated in biphasic and sarcomatoid histotypes (qRT-PCR and in situ hybridization analyses). Collectively, our findings indicate that epithelial-mesenchymal transition has a significant part in the morphological features of malignant mesothelioma. In particular, miR-205 downregulation correlated significantly with both a mesenchymal phenotype and a more aggressive behavior.

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The cytotoxic activities of new 2-alkyl-4,6-dihetero-(N,O)alkyl-1,3,5-triazines toward selected tumor cell lines have been evaluated, and for the first time, the potential of 2-alkyl-4,6-dialkoxy-1,3,5-triazines has been shown.

In our search for potential new anticancer drugs, we designed and synthesized a series of tricyclic compounds containing the antimitotic 2-phenylazaflavone chromophore fused to a pyrrole ring in a pyrroloquinoline structure. Compounds 8, 18, 19, 22, 23, 25 and 26, when tested against a panel of fourteen human tumor cell lines, showed poor in vitro cytotoxic activity, whereas 20, 21 and 24 showed significant activity (IC(50) 0.7 to 50 microM). Steroid hormone-sensitive ovary, liver, breast and adrenal gland adenocarcinoma cell lines displayed the highest sensitivity (IC(50) 0.7 to 8 microM). Compound 24 blocked cells in the G(2)/M phase of the cell cycle and induced a significant increase in apoptotis. Compounds 20, 21 and 24 proved to alter microtubule assembly and stability, displaying a cytoplasmic microtubule network similar to that caused by Vincristine. In vivo, administration of compound 24 to Balb/c mice inhibited the growth of a syngenic hepatocellular carcinoma.

No abstract

Vascular Endothelial Growth Factor (VEGF) pathway has emerged as one of the most important positive modulators of Angiogenesis, a central process implicated in tumour growth and metastatic dissemination. This led to the design and development of anti-VEGF monoclonal antibodies and small-molecule ATP-competitive VEGFR-inhibitors. In this study, we describe the synthesis and the biological evaluation of novel 2-aryl substituted benzothiopyrano-fused pyrimidines 1a-i, 2a-i and 3a-i. The ability of the compounds to target the VEGF pathway was determined in vitro exploiting the compounds' antiproliferative efficacy against HUVEC cells. The VEGFR-2 inhibition was confirmed by enzymatic assays on recombinant human kinase insert domain receptor (KDR), by cell-based phospho-VEGFR-2 inhibition assays, and by ex vivo rat aortic ring tests. The selectivity profile of the best performing derivatives belonging to series 2 was further explored combining modeling studies and additional assays in a panel of human cell lines and other kinases.

Two synthetic approaches to boehmeriasin A are described. A gram scale racemic preparation is accompanied by an efficient preparation of both the pure enantiomers using the conformationally stable 2-piperidin-2-yl acetaldehyde as starting material. The anti-proliferative activity in three cancer cell lines (CEM, HeLa and L1210) and two endothelial cell lines (HMEC-1, BAEC) indicates promising activity at the nanomolar range. Topoisomerases and SIRT2 are identified as biological targets and the experimental data has been supported by docking studies.