RESUMO
Glioblastoma (GB) is the most common malignant brain tumor. Drug resistance frequently develops in these tumors during chemotherapy. Therefore, predicting drug response in these patients remains a major challenge in the clinic. Thus, to improve the clinical outcome, more effective and tolerable combination treatment strategies are needed. Robust experimental evidence has shown that the main reason for failure of treatments is signal redundancy due to coactivation of several functionally linked receptor tyrosine kinases (RTKs), including anaplastic lymphoma kinase (ALK), c-Met (hepatocyte growth factor receptor), and oncogenic c-ros oncogene1 (ROS1: RTK class orphan) fusion kinase FIG (fused in GB)-ROS1. As such, these could be attractive targets for GB therapy. The study subjects consisted of 19 patients who underwent neurosurgical resection of GB tissues. Our in vitro and ex vivo models promisingly demonstrated that treatments with crizotinib (PF-02341066: dual ALK/c-Met inhibitor) and temozolomide in combination induced synergistic antitumor activity on FIG-ROS1-positive GB cells. Our results also showed that ex vivo FIG-ROS1+ slices (obtained from GB patients) when cultured were able to preserve tissue architecture, cell viability, and global gene-expression profiles for up to 14 days. Both in vitro and ex vivo studies indicated that combination blockade of FIG, p-ROS1, p-ALK, and p-Met augmented apoptosis, which mechanistically involves activation of Bim and inhibition of survivin, p-Akt, and Mcl-1 expression. However, it is important to note that we did not see any significant synergistic effect of crizotinib and temozolomide on FIG-ROS1-negative GB cells. Thus, these ex vivo culture results will have a significant impact on patient selection for clinical trials and in predicting response to crizotinib and temozolomide therapy. Further studies in different animal models of FIG-ROS1-positive GB cells are warranted to determine useful therapies for the management of human GBs.
RESUMO
A growing trend among ethanol drinkers, especially young adults, is to combine caffeinated energy drinks with ethanol during a drinking episode. The primary active ingredient of these mixers is caffeine, which may significantly interact with ethanol. We tested the two hypotheses that caffeine would enhance ethanol-conditioned place preference and also enhance ethanol-stimulated locomotor activity. The interactive pharmacology of ethanol and caffeine was examined in C57BL/6J (B6) mice in a conditioned place preference procedure with 1.75 g/kg ethanol and 3 mg/kg caffeine. Additionally, we used B6 mice to evaluate ethanol/caffeine combinations on locomotor activity using 3 doses of ethanol (1.75, 2.5 and 3.25 g/kg) and 2 two doses of caffeine (3 and 15 mg/kg). Both ethanol and caffeine administered alone increased preference for the drug paired side, although the effect of caffeine was more modest than that of ethanol. The drug combination produced significant place preference itself, but this was not greater than that for ethanol alone. Additionally, the combination of caffeine and ethanol significantly increased locomotion compared to giving either drug alone. The effect was strongest with a stimulatory dose of ethanol (1.75 g/kg) and waned with increasing doses of ethanol. Thus, combinations of caffeine and ethanol had significant conditioned reinforcing and locomotor activating effects in mice.