ABSTRACT
Our group has previously shown that corticotropin releasing factor (CRF) inhibits proliferation of human endocrine-related cancer cell lines via the activation of CRF type-1 receptors (CRF-R1). Tumors originating from the nervous system also express CRF receptors but their role on neoplastic cell proliferation was poorly investigated. Here we investigated the effect of CRF receptor stimulation on nervous system-derived cancer cells, using the SK-N-SH (N) human neuroblastoma cell line as an experimental model. We found that SK-N-SH (N) cells express functionally active CRF-R1, whose activation by CRF and the cognate peptide urocortin (UCN) is associated to reduced cell proliferation and motility, as well as neuronal-like differentiation. UCN did not interfere with cell viability and cell-cycle arrest. Those effects seem to be mediated by a mechanism involving the activation of cAMP/PKA/CREB pathway and the subsequent downstream increase in p27(Kip1) and underphosphorylated retinoblastoma protein levels, as well as reduced c-Myc mRNA accumulation.
Subject(s)
Cell Differentiation , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p27/physiology , Proto-Oncogene Proteins c-myc/metabolism , Receptors, Corticotropin-Releasing Hormone/metabolism , Cell Cycle Checkpoints , Cell Line, Tumor , Cell Movement , Corticotropin-Releasing Hormone/physiology , Down-Regulation , Gene Expression Regulation, Neoplastic , Humans , Neuroblastoma , Proto-Oncogene Proteins c-myc/genetics , Retinoblastoma Protein/metabolism , Urocortins/physiologyABSTRACT
An altered regulation of the corticotropin-releasing hormone (CRH) system in the CNS is consistently associated with anxiety and depression; several drugs used to treat CNS disorders modulate--usually in a negative manner--CRH turnover in the brain, and it can be postulated that their effectiveness may be at least in part related to their effects on CRH. This study was aimed to investigate the effects of two atypical antipsychotics also employed in the treatment of bipolar disorders, i.e. quetiapine (QTP) and olanzapine (OLZ), on CRH release from isolated rat brain regions. Acute rat hypothalamic and hippocampal explants were exposed for 1 h to plain medium or medium containing the test drugs, either under baseline conditions or after stimulation of CRH release by veratridine or 56 mM KCl. CRH immunoreactivity present in the incubation medium and in the tissues was assessed by radioimmunoassay. QTP 10 microM but not OLZ inhibited baseline CRH secretion from the hypothalamus; neither drug affected basal CRH release from the hippocampus. Both QTP and OLZ, 1 and 10 microM, inhibited veratridine- or K(+)-stimulated CRH release from the hypothalamus, whereas OLZ only, when given at 10 microM, was able to inhibit stimulated CRH release from the hippocampus. In conclusion, two widely used atypical antipsychotics, QTP and OLZ are able to acutely reduce the release of CRH from isolated rat hypothalami and hippocampi.
Subject(s)
Benzodiazepines/pharmacology , Brain/drug effects , Brain/metabolism , Corticotropin-Releasing Hormone/metabolism , Dibenzothiazepines/pharmacology , Animals , Corticotropin-Releasing Hormone/antagonists & inhibitors , Hippocampus/drug effects , Hippocampus/metabolism , Hypothalamus/drug effects , Hypothalamus/metabolism , Male , Olanzapine , Quetiapine Fumarate , Rats , Rats, WistarABSTRACT
PURPOSE: To determine the efficiency of transferring human zygotes as opposed to human day 2 or 3 embryos. METHODS: A prospective, randomized, Multicenter trial. Patients were randomized into zygote or embryo transfer. Patients were prepared for oocyte retrieval using standardized protocols. Oocyte retrieval was performed under general anesthesia. Oocytes and spermatozoa were treated using standard laboratory techniques. All protocols were coordinated by the coordinating center. RESULTS: A total of 386 patients were included in the trial. Pregnancy rates were 36.5% after zygote transfer and 42% after embryo transfer. Implantation rates were equivalent (17%) in both groups. CONCLUSIONS: No general difference was observed for zygote or embryo transfer. The results suggest that zygote transfer is a valid alternative to embryo transfer.
