VEGF-A drives T cell exhaustion via TOX-dependent transcriptional programming in microsatellite stable colorectal cancers.

WNT signaling activation in colorectal cancers (CRCs) occurs through APC inactivation or β-catenin mutations. Both processes promote β-catenin nuclear accumulation, which up-regulates epithelial-to-mesenchymal transition (EMT). We investigated β-catenin localization, transcriptome, and phenotypic differences of HCT116 cells containing a wild-type (HCT116-WT) or mutant β-catenin allele (HCT116-MT), or parental cells with both WT and mutant alleles (HCT116-P). We then analyzed β-catenin expression and associated phenotypes in CRC tissues. Wild-type β-catenin showed membranous localization, whereas mutant showed nuclear localization; both nuclear and non-nuclear localization were observed in HCT116-P. Microarray analysis revealed down-regulation of Claudin-7 and E-cadherin in HCT116-MT vs. HCT116-WT. Claudin-7 was also down-regulated in HCT116-P vs. HCT116-WT without E-cadherin dysregulation. We found that ZEB1 is a critical EMT factor for mutant β-catenin-mediated loss of E-cadherin and Claudin-7 in HCT116-P and HCT116-MT cells. We also demonstrated that E-cadherin binds to both WT and mutant β-catenin, and loss of E-cadherin releases β-catenin from the cell membrane and leads to its degradation. Alteration of Claudin-7, as well as both Claudin-7 and E-cadherin respectively caused tight junction (TJ) impairment in HCT116-P, and dual loss of TJs and adherens junctions (AJs) in HCT116-MT. TJ loss increased cell motility, and subsequent AJ loss further up-regulated that. Immunohistochemistry analysis of 101 CRCs revealed high (14.9%), low (52.5%), and undetectable (32.6%) β-catenin nuclear expression, and high β-catenin nuclear expression was significantly correlated with overall survival of CRC patients (P = 0.009). Our findings suggest that β-catenin activation induces EMT progression by modifying cell-cell junctions, and thereby contributes to CRC aggressiveness.

Aim. Robotic colorectal surgery may be a way to overcome the limitations of laparoscopic surgery. It is an emerging field; so, we aim in this paper to provide a comprehensive and data analysis of the available literature on the use of robotic technology in colorectal surgery. Method. A comprehensive systematic search of electronic databases was completed for the period from 2000 to 2011. Studies reporting outcomes of robotic colorectal surgery were identified and analyzed. Results. 41 studies (21 case series, 2 case controls, 13 comparative studies 1 prospective comparative, 1 randomized trial, 3 retrospective analyses) were reviewed. A total of 1681 patients are included in this paper; all of them use Da Vinci except 2 who use Zeus. Short-term outcome has been evaluated with 0 mortality and191 total major and minor complications. Pathological results were not analyzed in all studies and only 20 out of 41 provide data about the pathological results. Conclusion. Robotic surgery is safe and feasible option in colorectal surgery and a promising field; however, further prospective randomized studies are required to better define its role.

The microenvironment of breast cancer comprises predominantly of adipocytes. Adipocytes drive cancer progression through the secretion adipocytokines. Adipocytes induce epithelial mesenchymal transition of breast cancer cells through paracrine IL-6/Stat3 signalling. Treatment approaches that can target adipocytes in the microenvironment and abrogate paracrine signals that drive breast cancer growth and metastasis are urgently needed. Repositioning of old drugs has become an effective approach for discovering new cancer drugs. In this study, niclosamide, an FDA approved anthelminthic drug was evaluated for its anti-breast cancer activity and its ability to inhibit adipocytes induced EMT. Niclosamide potently inhibited proliferation, migration and invasion at low concentration and induced significant apoptosis at high concentrations in human breast cancer cell lines MDA-MB-468 and MCF-7. Additionally, niclosamide reversed adipocyte-induced EMT with a correlated inhibition of IL-6/Stat3 activation and downregulation of EMT-TFs TWIST and SNAIL. Moreover, niclosamide markedly impaired MDA-MB-468 and MCF-7 migration and invasion. We further found that the inhibitory effects of niclosamide on MDA-MB-468 and MCF-7 motility was closely related to destabilization of focal adhesion complex formation. With decreased co-localization of focal adhesion kinase (FAK) and phosphorylated paxillin (pPAX). Collectively, these results demonstrate that niclosamide could be used to inhibit adipocyte-induced breast cancer growth and metastasis.