The 27-kDa heat shock protein (HSP27) has a potent ability to increase cell survival in response to a wide range of cellular challenges. In order to investigate the mode of action of HSP27 in vivo, we have developed transgenic lines, which express human HSP27 at high levels throughout the brain, spinal cord, and other tissues. In view of the particular property of HSP27 compared with other HSPs to protect neurons against apoptosis, we have tested these transgenic lines in a well established in vivo model of neurotoxicity produced by kainic acid, where apoptotic cell death occurs. Our results demonstrate for the first time the marked protective effects of HSP27 overexpression in vivo, which significantly reduces kainate-induced seizure severity and mortality rate (>50%) in two independent lines and markedly reduces neuronal cell death in the CA3 region of hippocampus. This reduced seizure severity in HSP27 transgenic animals was associated with a marked attenuation of caspase 3 induction and apoptotic features. These studies clearly demonstrate that HSP27 has a major neuroprotective effect in the central nervous system in keeping with its properties demonstrated in culture and highlight an early stage in the cell death pathway that is affected by HSP27.The heat shock proteins (HSPs) 1 are a family of proteins originally identified as being up-regulated in response to elevated temperature, but now a wide range of cellular stresses such as hypoxia, ischemia, glutamate, and heavy metals have been shown to induce HSPs (1-6). HSPs consist of a family of highly conserved proteins grouped according to their molecular size: the high molecular mass proteins (110, 90, 70 -72, and 55-60 kDa) and the small HSPs, which include HSP27, ubiquitin, ␣A-and ␣B-crystallin, and related species. Although highly conserved across species, variation in protein size occurs; for example, the 27-kDa human HSP27 has a corresponding isoform of 25 kDa in rodents referred to as HSP25. HSPs are both constitutively expressed and induced in response to stressful stimuli (e.g. HSP27 and HSP70). Rapid induction of HSP expression is mediated by specific heat shock factors (heat shock factors 1-4), which regulate transcription (7).The HSPs play a key role in cellular defense systems, acting as protein chaperones facilitating protein folding and the removal of aberrant proteins. These properties have been shown to contribute to the enhanced cellular survival produced following preconditioning stimuli in which a subthreshold stimulus is used to raise endogenous heat shock protein levels prior to the main stimulus. Primary neuronal cultures are protected by prior exposure to mild heat or ischemic stress before subsequent more severe heat or ischemic stress or exposure to glutamate (8 -10). In cardiac tissue, a mild heat shock also protects against a subsequent thermal or ischemic stress (11).The effects of heat shock can be mimicked by overexpression of HSPs alone. Both the ND7 immortalized neuronal cell line, which is derived from dorsal root ganglia ...

Purpose: On September 24, 2009, the U.S. Food and Drug Administration granted accelerated approval for Folotyn (pralatrexate injection, Allos Therapeutics, Inc.) as a single agent for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma (PTCL); it is the first drug approved for this indication.Experimental Design: This review was based on study PDX-008, a phase II, single-arm, nonrandomized, open-label, international, multicenter trial, designed to evaluate the safety and efficacy of pralatrexate when administered concurrently with vitamin B 12 and folic acid supplementation in patients with relapsed or refractory PTCL.Results: The overall response rate was 27% in 109 evaluable patients [95% confidence interval (CI), 19-36%]. Twelve percent of 109 evaluable patients (95% CI, 7-20%)] had a response duration of ≥14 weeks. Six of these 13 patients achieved a complete response, and one patient had complete response unconfirmed. The most common grade 3 and 4 toxicities were thrombocytopenia, mucositis, and neutropenia.Conclusion: This accelerated approval was based on a response rate that is reasonably likely to predict clinical benefit in this heavily pretreated patient population with this rare disease. The applicant has committed to conducting postmarketing clinical trials to assess clinical benefit. The recommended starting dose of pralatrexate in patients with relapsed or refractory PTCL is 30 mg/m 2 via intravenous push over 3 to 5 min weekly for 6 weeks followed by a one-week rest (one cycle). Intramuscular injection of 1 mg vitamin B 12 should be administered every 8 to 10 weeks along with 1.0 mg folic acid given orally once a day. Clin Cancer Res; 16(20); 4921-7. ©2010 AACR.

Previous work has shown that hydroxysafflor yellow A (HSYA), extracted from Carthamus tinctorius L. markedly extended the coagulation time in mice and exhibited a significant antithrombotic effect in rats. The present study was conducted to demonstrate further its neuroprotective effects on cerebral ischemic injury in both in vivo and in vitro studies. In vivo, male Wistar-Kyoto (WKY) rats with middle cerebral artery occlusion (MCAO) were evaluated for neurological deficit scores followed by the treatment with a single dose of HSYA. Furthermore, the infarction area of the brain was assessed in the brain slices. In vitro, the effect of HSYA was tested in cultured fetal cortical cells exposed to glutamate and sodium cyanide (NaCN) to identify its neuroprotection against neurons damage. The results in vivo showed that sublingular vein injection of HSYA at doses of 3.0 mg/kg and 6.0 mg/kg exerted significant neuroprotective effects on rats with focal cerebral ischemic injury by significantly decreasing neurological deficit scores and reducing the infarct area compared with the saline group, HSYA at a dose of 6.0 mg/kg showed a similar potency as nimodipine at a dose of 0.2 mg/kg. Sublingular vein injection of HSYA at the dose of 1.5 mg/kg showed a neuroprotective effect, however, with no significant difference when compared with the saline group. Results in vitro showed that HSYA significantly inhibited neuron damage induced by exposure to glutamate and sodium cyanide (NaCN) in cultured fetal cortical cells. Noticeably, the neuroprotective action of HSYA on glutamate-mediated neuron injury was much better than that of HSYA on NaCN-induced neuron damage. All these findings suggest that HSYA might act as a potential neuroprotective agent useful in the treatment in focal cerebral ischemia. Abbreviations. HSYA:hydroxysafflor yellow A TTC:2,3,5-triphenyltetrazolium chloride MTT:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide DMEM:Dulbecco's modified Eagle medium FCS:Fetal calf serum MCAO:middle cerebral artery occlusion ECA:external carotid artery ICA:internal carotid artery LDH:lactate dehydrogenase NMDA: N-methyl- D-aspartate

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