ABSTRACT
Pomalidomide, a derivative of thalidomide, is an effective treatment for multiple myeloma. The drug exerts its effects through CRBN, a component of the E3 ubiquitin ligase complex CRL4CRBN. To search for novel factors involved in the anti-cancer activity of pomalidomide, we performed a genome-wide shRNA library screen and identified 445 genes as those affecting pomalidomide sensitivity. Genes encoding components of the ubiquitin-proteasome pathway, such as subunits of the CRL4CRBN complex, the COP9 signalosome, and the 26S proteasome, were among the pomalidomide-affecting genes. Karyopherin beta 1 (KPNB1) was identified as a novel pomalidomide-affecting gene. KPNB1 was required for the nuclear import of CRBN and for the CRBN-directed, pomalidomide-dependent degradation of a clinically relevant substrate, the transcription factor Aiolos. By contrast, the cytoplasmic translation factor GSPT1 was degraded following treatment with the thalidomide derivative CC-885 only when CRBN was present in the cytoplasm, indicating that subcellular distribution of CRBN is critical for the efficacy of thalidomide-based medications.
Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Multiple Myeloma/metabolism , Neoplasm Proteins/metabolism , Thalidomide/analogs & derivatives , Ubiquitin-Protein Ligases/metabolism , Adaptor Proteins, Signal Transducing/genetics , Cell Line, Tumor , Genome-Wide Association Study , Humans , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Neoplasm Proteins/genetics , Phenylurea Compounds/pharmacology , Thalidomide/pharmacology , Ubiquitin-Protein Ligases/geneticsABSTRACT
AIM: To measure the bacterial genome in ocular fluids and to analyse the clinical relevance of infectious endophthalmitis. METHODS: Nineteen ocular fluid samples (eight aqueous humour and 11 vitreous fluid samples) were collected from 19 patients with suspected bacterial endophthalmitis. Fifty ocular samples from uveitis patients were also collected along with 40 samples from patients without ocular inflammation and used as controls. Bacterial ribosomal DNA (16S rDNA) was measured by a quantitative PCR assay. RESULTS: Bacterial 16S rDNA was detected in patients with clinically suspected bacterial endophthalmitis (18/19, 95%). With the exception of one case, high copy numbers of bacterial DNA were detected (1.7×10(3)-1.7×10(9) copies/ml) in these patients. There were 10 samples (53%) with positive bacterial cultures while there were nine samples (47%) with positive Gram-staining. Real-time PCR detected bacterial 16S rDNA in three (6%) of the 50 samples from the control uveitis patients. In addition, none of the samples from the control patients without intraocular inflammation were positive. CONCLUSIONS: Quantitative broad-range PCR of bacterial 16S rDNA is a useful tool for diagnosing bacterial endophthalmitis.
Subject(s)
DNA, Bacterial/analysis , DNA, Ribosomal/analysis , Endophthalmitis/diagnosis , Eye Infections, Bacterial/diagnosis , Polymerase Chain Reaction/methods , Uveitis/microbiology , Vitreous Body/microbiology , Aged , Endophthalmitis/microbiology , Eye Infections, Bacterial/microbiology , Female , Humans , Male , Prospective Studies , RNA, Ribosomal, 16S/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Measles virus (MeV) research is largely dependent on the B95a cell line, which is derived from marmoset B lymphocytes. As this cell line is persistently infected with Epstein-Barr virus (EBV), a novel cell line, COBL-a, was established from human umbilical cord blood. COBL-a cells have a significant advantage over B95a cells because they are of human origin, are free from EBV and have higher sensitivity to wild-type MeV. Thus, COBL-a cells should prove very valuable for both epidemiological and basic studies of MeV.
