Temozolomide for treatment of brain metastases: A review of 21 clinical trials.

Brain metastases from solid tumours are associated with poor prognosis despite aggressive treatment. Temozolomide can be used for the treatment of glioblastoma multiforme as well as melanoma. It has also been shown to have activity in patients with brain metastases from various malignancies, since it can cross the blood-brain barrier. To better understand the efficacy of temozolomide in the treatment of brain metastases, we carried out a review of 21 published clinical trials to determine whether temozolomide would benefit patients with brain metastases from solid tumours. Information regarding complete response, partial response, stable disease, objective response and objective response rate were collected to assess clinical outcomes. A modest therapeutic effect was observed when temozolomide was used as a single agent, however, the combination of temozolomide with whole-brain radiotherapy and/or other anticancer drugs exhibited encouraging activity. Thus, future high quality studies are warranted to confirm our findings.

Sphingomyelinase-induced ceramide production stimulate calcium-independent JNK and PP2A activation following cerebral ischemia.

PRIMARY OBJECTIVE: Intracellular calcium overload is considered to be a key pathologic factor for ischemic stroke; however, there are other signal molecules produced in response to ischemic stimuli. The present study investigated the ceramide signal pathway, which is associated with cerebral ischemia in a calcium-independent manner. METHODS: Male Sprague-Dawley rats were subjected to 10-minute four-vessel occlusion. Ketamine, a blocker of calcium-ion channels, or TPCK or fumonisin B1, inhibitors of ceramide production in the sphingomyelinase and de novo pathways, respectively, were administrated to the rats prior to inducing ischemia. Ceramide levels were determined by immunofluorescence, protein activity was assessed by immunoblotting and PP2A activity was measured using a protein phosphatase assay system. RESULTS: The morphologic data indicated that ischemia-induced ceramide production was largely restricted to glia cells in the rat hippocampus. TPCK, but not ketamine or fumonisin B1, blocked the ceramide pathway and its downstream molecules, JNK and PP2A. CONCLUSIONS: Cerebral ischemia up-regulates the sphingomyelin-ceramide pathway, which involves calcium-independent JNK and PP2A activation in hippocampal glia; this may play a significant role in cerebral lesions post-ischemia.