The results of this multicenter study on CBD treatment for intractable epilepsy in a population of children and adolescents are highly promising. Further prospective, well-designed clinical trials using enriched CBD medical cannabis are warranted.

The p53 tumor suppressor exerts a variety of cell-autonomous effects that are aimed to thwart tumor development. In addition, however, there is growing evidence for cell nonautonomous tumor suppressor effects of p53. In the present study, we investigated the impact of stromal p53 on tumor growth. Specifically, we found that ablation of p53 in fibroblasts enabled them to promote more efficiently the growth of tumors initiated by PC3 prostate cancer-derived cells. This stimulatory effect was dependent on the increased expression of the chemokine SDF-1 in the p53-deficient fibroblasts. Notably, fibroblasts harboring mutant p53 protein were more effective than p53-null fibroblasts in promoting tumor growth. The presence of either p53-null or p53-mutant fibroblasts led also to a markedly elevated rate of metastatic spread of the PC3 tumors. These findings implicate p53 in a cell nonautonomous tumor suppressor role within stromal fibroblasts, through suppressing the production of tumor stimulatory factors by these cells. Moreover, expression of mutant p53 by tumor stroma fibroblasts might exert a gain of function effect, further accelerating tumor development. Cancer Res; 70(23); 9650-8.Ó2010 AACR.

Tumor-associated stroma, in general, and tumor fibroblasts and myofibroblasts, in particular, play a role in tumor progression. We previously reported that myofibroblast infiltration into implanted ovarian carcinoma spheroids marked the exit of tumors from dormancy and that these cells contributed to vascular stabilization in ovarian tumors by expression of angiopoietin-1 and angiopoietin-2. Ex vivo labeling of fibroblasts with either magnetic resonance or optical probes rendered them detectable for in vivo imaging. Thus, magnetic resonance imaging (MRI) follow-up was feasible by biotin-bovine serum albumin-gadolinium diethylenetriaminepentaacetic acid or iron oxide particles, whereas labeling with near-IR and fluorescent vital stains enabled in vivo visualization by near-IR imaging and twophoton microscopy. Using this approach, we show here that prelabeled fibroblasts given i.p. to CD-1 nude mice can be followed in vivo by MRI and optical imaging over several days, revealing their extensive recruitment into the stroma of remote s.c. MLS human epithelial ovarian carcinoma tumors. Two-photon microscopy revealed the alignment of these invading fibroblasts in the outer rim of the tumor, colocalizing with the angiogenic neovasculature. Such angiogenic vessels remained confined to the stroma tracks within the tumor and did not penetrate the tumor nodules. These results provide dynamic evidence for the role of tumor fibroblasts in maintenance of functional tumor vasculature and offer means for image-guided targeting of these abundant stroma cells to the tumor as a possible mechanism for cellular cancer therapy.

EmrE is a 12-kDa Escherichia coli multidrug transporter that confers resistance to a wide variety of toxic reagents by actively removing them in exchange for hydrogen ions. The three native Cys residues in EmrE are inaccessible to N-ethylmaleimide (NEM) and a series of other sulfhydryls. In addition, each of the three residues can be replaced with Ser without significant loss of activity. A protein without all the three Cys residues (Cysless) has been generated and shown to be functional. Using this Cys-less protein, we have now generated a series of 48 single Cys replacements throughout the protein. The majority of them (43) show transport activity as judged from the ability of the mutant proteins to confer resistance against toxic compounds and from in vitro analysis of their activity in proteoliposomes. Here we describe the use of these mutants to study the accessibility to NEM, a membrane permeant sulfhydryl reagent. The study has been done systematically so that in one transmembrane segment (TMS2) each single residue was replaced. In each of the other three transmembrane segments, at least four residues covering one turn of the helix were replaced. The results show that although the residues in putative hydrophilic loops readily react with NEM, none of the residues in putative transmembrane domains are accessible to the reagent. The results imply very tight packing of the protein without any continuous aqueous domain. Based on the findings described in this work, we conclude that in EmrE the substrates are translocated through a hydrophobic pathway.