Histone deacetylase inhibitor vorinostat suppresses the growth of uterine sarcomas in vitro and in vivo

<p>Abstract</p> <p>Background</p> <p>Uterine sarcomas are very rare malignancies with no approved chemotherapy protocols. Histone deacetylase (HDAC) inhibitors belong to the most promising groups of compounds for molecular targeting therapy. Here, we described the antitumor effects of suberoylanilide hydroxamic acid (SAHA; vorinostat) on MES-SA uterine sarcoma cells <it>in vitro </it>and <it>in vivo</it>. We investigated effects of vorinostat on growth and colony forming ability by using uterine sarcoma MES-SA cells. We analyzed the influence of vorinostat on expression of different HDACs, p21^WAF1and activation of apoptosis. Finally, we examined the antitumor effects of vorinostat on uterine sarcoma <it>in vivo</it>.</p> <p>Results</p> <p>Vorinostat efficiently suppressed MES-SA cell growth at a low dosage (3 μM) already after 24 hours treatment. Decrease of cell survival was even more pronounced after prolonged treatment and reached 9% and 2% after 48 and 72 hours of treatment, respectively. Colony forming capability of MES-SA cells treated with 3 μM vorinostat for 24 and 48 hours was significantly diminished and blocked after 72 hours. HDACs class I (HDAC2 and 3) as well as class II (HDAC7) were preferentially affected by this treatment. Vorinostat significantly increased p21^WAF1expression and apoptosis. Nude mice injected with 5 × 10⁶MES-SA cells were treated for 21 days with vorinostat (50 mg/kg/day) and, in comparison to placebo group, a tumor growth reduction of more than 50% was observed. Results obtained by light- and electron-microscopy suggested pronounced activation of apoptosis in tumors isolated from vorinostat-treated mice.</p> <p>Conclusions</p> <p>Our data strongly indicate the high therapeutic potential of vorinostat in uterine sarcomas.</p

Acyl chain-dependent effect of lysophosphatidylcholine on endothelial prostacyclin production

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Targeting TMEM16A to reverse vasoconstriction and remodelling in idiopathic PAH

Our systematic analysis of anion channels and transporters in idiopathic pulmonary arterial hypertension (IPAH) showed marked upregulation of the Cl- channel TMEM16A gene.We hypothesised that TMEM16A overexpression might represent a novel vicious circle in the molecular pathways causing PAH.We investigated healthy donor lungs (n=40) and recipient lungs with IPAH (n=38) for the expression of anion channel and transporter genes in small pulmonary arteries and pulmonary arterial smooth muscle cells (PASMC). In IPAH, TMEM16A was strongly upregulated and patch-clamp recordings confirmed an increased Cl- current in PASMC (n=9-10). These cells were depolarised and could be repolarized by TMEM16A inhibitors or knock-down experiments (n=6-10). Inhibition/knock-down of TMEM16A reduced proliferation of IPAH-PASMC (n=6). Conversely, overexpression of TMEM16A in healthy donor PASMC produced an IPAH-like phenotype. Chronic application of benzbromarone in two independent animal models significantly decreased right ventricular pressure and reversed remodelling of established PH.Our findings suggest that increased TMEM16A expression and activity comprise an important pathologic mechanism underlying vasoconstriction and remodelling of pulmonary arteries in PAH. Inhibition of TMEM16A represents a novel therapeutic approach to achieve reverse remodelling in PAH

15d-PGJ2 Promotes ROS-Dependent Activation of MAPK-Induced Early Apoptosis in Osteosarcoma Cell In Vitro and in an Ex Ovo CAM Assay

Osteosarcoma (OS) is the most common type of bone tumor, and has limited therapy options. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has striking anti-tumor effects in various tumors. Here, we investigated molecular mechanisms that mediate anti-tumor effects of 15d-PGJ2 in different OS cell lines. Human U2-OS and Saos-2 cells were treated with 15d-PGJ2 and cell survival was measured by MTT assay. Cell proliferation and motility were investigated by scratch assay, the tumorigenic capacity by colony forming assay. Intracellular ROS was estimated by H2DCFDA. Activation of MAPKs and cytoprotective proteins was detected by immunoblotting. Apoptosis was detected by immunoblotting and Annexin V/PI staining. The ex ovo CAM model was used to study growth capability of grafted 15d-PGJ2-treated OS cells, followed by immunohistochemistry with hematoxylin/eosin and Ki-67. 15d-PGJ2 substantially decreased cell viability, colony formation and wound closure capability of OS cells. Non-malignant human osteoblast was less affected by 15d-PGJ2. 15d-PGJ2 induced rapid intracellular ROS production and time-dependent activation of MAPKs (pERK1/2, pJNK and pp38). Tempol efficiently inhibited 15d-PGJ2-induced ERK1/2 activation, while N-acetylcystein and pyrrolidine dithiocarbamate were less effective. Early but weak activation of cytoprotective proteins was overrun by induction of apoptosis. A structural analogue, 9,10-dihydro-15d-PGJ2, did not show toxic effects in OS cells. In the CAM model, we grafted OS tumors with U2-OS, Saos-2 and MG-63 cells. 15d-PGJ2 treatment resulted in significant growth inhibition, diminished tumor tissue density, and reduced tumor cell proliferation for all cell lines. Our in vitro and CAM data suggest 15d-PGJ2 as a promising natural compound to interfere with OS tumor growth