Effects of cisplatin and panobinostat on human mesothelial (Met-5A) and malignant pleural mesothelioma (MSTO-211H) cells.

New therapeutic approaches are still needed for effective malignant pleural mesothelioma treatment. The use of classical chemotherapy agents in combination with newly developed molecules may shed light on new therapeutic approaches. We aimed to determine the efficacy of panobinostat, alone and in combination with cisplatin, on cell survival and mRNA expression of FOXO3A, CCND1, and CASP9 genes in both mesothelioma and healthy mesothelial cell lines. Cells were treated with 1-100 µM cisplatin and 25-1000 nM panobinostat. Methylthiazol tetrazolium assays were performed to determine cell viability. mRNA expression levels of genes were analyzed with quantitative real-time polymerase chain reaction. Cisplatin and panobinostat exposure of the cells for 24 h resulted in decreased cell survival. The combined treatment was found to be more effective. No significant changes were observed with respect to CCND1 expression after exposure to agents alone or in combination. However, agents in combination resulted in upregulation of FOXO3A and CASP9 in MSTO-211H cells. Gene expression levels were not affected by any agents in healthy cells. Use of cisplatin in combination with new chemotherapeutic agents may reduce the toxic effects of cisplatin in normal cells and result in more effective removal of tumor cells.

A 200-second quasi-periodicity after the tidal disruption of a star by a dormant black hole.

Supermassive black holes (SMBHs; mass is greater than or approximately 10(5) times that of the Sun) are known to exist at the center of most galaxies with sufficient stellar mass. In the local universe, it is possible to infer their properties from the surrounding stars or gas. However, at high redshifts we require active, continuous accretion to infer the presence of the SMBHs, which often comes in the form of long-term accretion in active galactic nuclei. SMBHs can also capture and tidally disrupt stars orbiting nearby, resulting in bright flares from otherwise quiescent black holes. Here, we report on a ~200-second x-ray quasi-periodicity around a previously dormant SMBH located in the center of a galaxy at redshift z = 0.3534. This result may open the possibility of probing general relativity beyond our local universe.

A Single Circumbinary Disk in the HD 98800 Quadruple System.

We present subarcsecond thermal infrared imaging of HD 98800, a young quadruple system composed of a pair of low-mass spectroscopic binaries separated by 0&farcs;8 (38 AU), each with a K-dwarf primary. Images at wavelengths ranging from 5 to 24.5 µm show unequivocally that the optically fainter binary, HD 98800B, is the sole source of a comparatively large infrared excess on which a silicate emission feature is superposed. The excess is detected only at wavelengths of 7.9 µm and longer, peaks at 25 µm, and has a best-fit blackbody temperature of 150 K, indicating that most of the dust lies at distances greater than the orbital separation of the spectroscopic binary. We estimate the radial extent of the dust with a disk model that approximates radiation from the spectroscopic binary as a single source of equivalent luminosity. Given the data, the most likely values of disk properties in the ranges considered are Rin=5.0+/-2.5 AU, DeltaR=13+/-8 AU, lambda0=2+4-1.5 µm, gamma=0+/-2.5, and sigmatotal=16+/-3 AU2, where Rin is the inner radius, DeltaR is the radial extent of the disk, lambda0 is the effective grain size, gamma is the radial power-law exponent of the optical depth tau, and sigmatotal is the total cross section of the grains. The range of implied disk masses is 0.001-0.1 times that of the Moon. These results show that, for a wide range of possible disk properties, a circumbinary disk is far more likely than a narrow ring.