The ATP-gated receptor P2X is expressed in multiple malignant tumours including neuroblastoma, melanoma, prostate, lung and breast. P2X has a significant role in mediating diverse cell responses, which upon dysregulation are associated with tumour initiation and development. The rapid, ATP-mediated activation of P2X induces a fast-inward cation current in cells. However, prolonged ATP-mediated activation of P2X leads to formation of a pore that increases membrane permeability and eventually causes cell death. This presents a potential paradox, as the tumour microenvironment contains extracellular ATP at levels sufficient to activate the P2X pore and trigger cell death. However, P2X expression is associated with enhanced cancer cell survival, proliferation and metastatic potential. At least one distinct conformational form of P2X, termed non-pore functional P2X (nfP2X), has been described, which is not able to form a functional pore. We demonstrate for the first time in this study that exposure to a high ATP concentration, equivalent to those measured in the tumour microenvironment, drives nfP2X expression and also that nfP2X is essential for tumour cell survival. We show that monoclonal antibodies raised against a P2X amino acid sequence (200-216), whose conformation is distinct from that of wild-type (WT) P2X, bind specifically to nfP2X expressed on the surface of tumour cells. We also show that nfP2X is broadly expressed in patient-derived tumour sections from a wide range of cancers. Therefore, antibodies raised against E200 provide tools that can differentiate between forms of the P2X receptor that have a key role in cancer.

BackgroundTransplantation of adventitial pericytes (APCs) promotes cardiac repair in murine models of myocardial infarction. The aim of present study was to confirm the benefit of APC therapy in a large animal model.Methods and ResultsWe performed a blind, randomized, placebo‐controlled APC therapy trial in a swine model of reperfused myocardial infarction. A first study used human APCs (hAPCs) from patients undergoing coronary artery bypass graft surgery. A second study used allogeneic swine APCs (sAPCs). Primary end points were (1) ejection fraction as assessed by cardiac magnetic resonance imaging and (2) myocardial vascularization and fibrosis as determined by immunohistochemistry. Transplantation of hAPCs reduced fibrosis but failed to improve the other efficacy end points. Incompatibility of the xenogeneic model was suggested by the occurrence of a cytotoxic response following in vitro challenge of hAPCs with swine spleen lymphocytes and the failure to retrieve hAPCs in transplanted hearts. We next considered sAPCs as an alternative. Flow cytometry, immunocytochemistry, and functional/cytotoxic assays indicate that sAPCs are a surrogate of hAPCs. Transplantation of allogeneic sAPCs benefited capillary density and fibrosis but did not improve cardiac magnetic resonance imaging indices of contractility. Transplanted cells were detected in the border zone.ConclusionsImmunologic barriers limit the applicability of a xenogeneic swine model to assess hAPC efficacy. On the other hand, we newly show that transplantation of allogeneic sAPCs is feasible, safe, and immunologically acceptable. The approach induces proangiogenic and antifibrotic benefits, though these effects were not enough to result in functional improvements.

Background: Cutaneous squamous cell carcinoma (cSCC) incidence continues to rise with increasing morbidity and mortality, with limited treatment options for advanced disease. Future improvements in targeted therapy will rely on advances in genomic/transcriptomic understanding and the use of model systems for basic research. We describe here the panel of 16 primary and metastatic cSCC cell lines developed and characterised over the past three decades in our laboratory in order to provide such a resource for future preclinical research and drug screening. Methods: Primary keratinocytes were isolated from cSCC tumours and metastases, and cell lines were established. These were characterised using short tandem repeat (STR) profiling and genotyped by whole exome sequencing. Multiple in vitro assays were performed to document their morphology, growth characteristics, migration and invasion characteristics, and in vivo xenograft growth. Results: STR profiles of the cSCC lines allow the confirmation of their unique identity. Phylogenetic trees derived from exome sequence analysis of the matched primary and metastatic lines provide insight into the genetic basis of disease progression. The results of in vivo and in vitro analyses allow researchers to select suitable cell lines for specific experimentation. Conclusions: There are few well-characterised cSCC lines available for widespread preclinical experimentation and drug screening. The described cSCC cell line panel provides a critical tool for in vitro and in vivo experimentation.

Southwest Oncology Group (Bernstein et al, 2009). As expected, these patients had more advanced disease and more frequent extranodal localization at presentation. In this study, we demonstrated that the addition of rituximab to CHOP was associated with a reduction in the incidence of secondary CNS involvement. Moreover, compared to the pre-rituximab era, progression during systemic treatment is less frequent, CNS relapses tend to be isolated and, most strikingly, leptomeningeal involvement is uncommon. These findings are similar to the Vancouver group's study (Villa et al, 2010). The reduced incidence of secondary CNS involvement was also demonstrated by Boehme et al, 2009; and Shimazu et al, 2009;. However, a greater proportion of leptomeningeal relapses in R-CHOP-treated patients was observed in the former study. Conversely, the addition of rituximab did not change the incidence of secondary CNS involvement in the other three studies (Feugier et al, 2004; : Yamamoto et al, 2010; Tai et al, 2011). In contrast to previous studies, our R-CHOP-treated patients with secondary CNS involvement were younger and, probably for that reason, half of them were successfully salvaged with second-line treatment.