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Objective: Cancer stem cells (CSCs) are responsible for tumour formation and spreading, and their targeting is required for tumour eradication. There are limited therapeutic options for advanced colorectal cancer (CRC), particularly for tumours carrying RAS-activating mutations. The aim of this study was to identify novel CSC-targeting strategies., Design: To discover potential therapeutics to be clinically investigated as single agent, we performed a screening with a panel of FDA-approved or investigational drugs on primary CRC cells enriched for CSCs (CRC-SCs) isolated from 27 patients. Candidate predictive biomarkers of efficacy were identified by integrating genomic, reverse-phase protein microarray (RPPA) and cytogenetic analyses, and validated by immunostainings. DNA replication stress (RS) was increased by employing DNA replication-perturbing or polyploidising agents., Results: The drug-library screening led to the identification of LY2606368 as a potent anti-CSC agent acting in vitro and in vivo in tumour cells from a considerable number of patients (∼36%). By inhibiting checkpoint kinase (CHK)1, LY2606368 affected DNA replication in most CRC-SCs, including RAS-mutated ones, forcing them into premature, lethal mitoses. Parallel genomic, RPPA and cytogenetic analyses indicated that CRC-SCs sensitive to LY2606368 displayed signs of ongoing RS response, including the phosphorylation of RPA32 and ataxia telangiectasia mutated serine/threonine kinase (ATM). This was associated with mutation(s) in TP53 and hyperdiploidy, and made these CRC-SCs exquisitely dependent on CHK1 function. Accordingly, experimental increase of RS sensitised resistant CRC-SCs to LY2606368., Conclusions: LY2606368 selectively eliminates replication-stressed, p53-deficient and hyperdiploid CRC-SCs independently of RAS mutational status. These results provide a strong rationale for biomarker-driven clinical trials with LY2606368 in patients with CRC., Competing Interests: Competing interests: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

The DNA damage response (DDR) network is exploited by cancer cells to withstand chemotherapy. Gastric cancer (GC) carries deregulation of the DDR and harbors genetic defects that fuel its activation. The ATM-Chk2 and ATR-Chk1-Wee1 axes are deputed to initiate DNA repair. Overactivation of these pathways in cancer cells may represent an adaptive response for compensating genetic defects deregulating G 1 -S transition (e.g., TP53) and ATM/ATR-initiated DNA repair (e.g., ARID1A). We hypothesized that DDR-linked biomarkers may predict clinical outcomes in GC patients treated with chemotherapy. Immunohistochemical assessment of DDR kinases (pATM, pChk2, pChk1 and pWee1) and DNA damage markers (γ-H2AX and pRPA32) was performed in biological samples from 110 advanced GC patients treated with first-line chemotherapy, either in phase II trials or in routine clinical practice. In 90 patients, this characterization was integrated with targeted ultra-deep sequencing for evaluating the mutational status of TP53 and ARID1A. We recorded a positive association between the investigated biomarkers. The combination of two biomarkers (γ-H2AX high /pATM high ) was an adverse factor for both progression-free survival (multivariate Cox: HR 2.23, 95%CI: 1.47-3.40) and overall survival (multivariate Cox: HR: 2.07, 95%CI: 1.20-3.58). The relationship between the γ-H2AX high /pATM high model and progression-free survival was consistent across the different TP53 backgrounds and was maintained in the ARID1A wild-type setting. Conversely, this association was no longer observed in an ARID1A-mutated subgroup. The γ-H2AX high /pATM high model negatively impacted survival outcomes in GC patients treated with chemotherapy. The mutational status of ARID1A, but apparently not TP53 mutations, affects its predictive significance., (© 2017 UICC.)

We have previously shown that melatonin exerts tumor suppressor activities by inducing the p38-p53 axis. This occurred within a few hours while no data are available on how melatonin pathway can be sustained on the long term. Here we show that miR-24, which has been demonstrated to target genes involved in the DNA repair process, targets p38, p53, PML and H2AX simultaneously. We show that long-term treatment with melatonin can decrease miR-24 levels post-transcriptionally, which pairs with a long-wave regulation of genes involved in cell proliferation, DNA damage, RNA metabolism and cell shape and transformation. Moreover, we show that melatonin can inhibit cell proliferation and migration, at least in part, by downregulating miR-24. Furthermore, we propose the involvement of hnRNP A1, which is downregulated by melatonin and involved in miRNA processing, in the regulation of miR-24 levels by melatonin. We conclude showing that miR-24 is upregulated in colon, breast and head and neck datasets and its levels negatively correlate with overall survival.

There is not a consensus on the best therapeutic approach to mesothelioma and the prognosis is still dismal. We have recently demonstrated that HtrA1 is a potential therapeutic target in mesothelioma cells. In this manuscript we describe that electroporation in a mouse mesothelioma xenograft was able to facilitate the expression of exogenous HtrA1 injected intra-lesionally in the tumors and to increase the penetration in the neoplastic cells of cisplatin given intra-peritoneally. Indeed, HtrA1 over-expression caused a significant slowing down of tumor growth; moreover, cisplatin efficacy in reducing tumor mass was amplified by electroporation and this phenomenon was even more significant when combining the electroporation of cisplatin and HtrA1. Considering that a substantial number of mesothelioma patients develop early local recurrence, even with radical resection combined with aggressive chemo- and radiotherapy, this multi-modality approach could be very effective in improving local tumor control after surgery. The identification of effective combination coupled with the development of novel equipments and electrodes will be instrumental in planning the translation of these results to humans as per correct laboratory-clinical interface.

This paper reports the clinical findings, histopathology, and clinical outcome of a rare case of aponeurotic fibromatosis in a dog. The dog was treated with 4 courses of electrochemotherapy using the drugs cisplatin and bleomycin. There was complete remission and the dog was still disease-free after 18 months.

Electrochemotherapy is a tumor treatment that adapts the systemic or local delivery of anticancer drugs by the application of permeabilizing electric pulses with appropriate amplitude and waveforms. This allows the use of lipophobic drugs, which frequently have a narrow therapeutic index, with a decreased morbidity for the patient, while maintaining appropriate anticancer efficacy. Electrochemotherapy is used in humans for the treatment of cutaneous neoplasms or the palliation of skin tumor metastases, and a standard operating procedure has been devised. In veterinary oncology, the electrochemotherapy approach is gaining popularity, becoming a first-line treatment in consideration of its high efficacy and low toxicity. This review summarizes the state of the art in veterinary oncology as a preclinical model.

Background: Solid tumours are less oxygenated than normal tissues. Consequently, cancer cells acquire to be adapted to a hypoxic environment. The poor oxygenation of solid tumours is also a major indicator of an adverse cancer prognosis and leads to resistance to conventional anticancer treatments. We previously showed the involvement of Che-1/AATF (Che-1) in cancer cell survival under stress conditions. Herein we hypothesized that Che-1 plays a role in the response of cancer cells to hypoxia. Methods: The human colon adenocarcinoma HCT116 and HT29 cell lines undepleted or depleted for Che-1 expression by siRNA, were treated under normoxic and hypoxic conditions to perform studies regarding the role of this protein in metabolic adaptation and cell proliferation. Che-1 expression was detected using western blot assays; cell metabolism was assessed by NMR spectroscopy and functional assays. Additional molecular studies were performed by RNA seq, qRT-PCR and ChIP analyses. Results: Here we report that Che-1 expression is required for the adaptation of cells to hypoxia, playing an important role in metabolic modulation. Indeed, Che-1 depletion impacted on HIF-1a stabilization, thus downregulating the expression of several genes involved in the response to hypoxia and affecting glucose metabolism. Conclusions: We show that Che-1 a novel player in the regulation of HIF-1a in response to hypoxia. Notably, we found that Che-1 is required for SIAH-2 expression, a member of E3 ubiquitin ligase family that is involved in the degradation of the hydroxylase PHD3, the master regulator of HIF-1a stability. [ABSTRACT FROM AUTHOR]

We have previously reported that nuclear expression of the Hippo transducer TAZ in association with Wnt pathway mutations negatively impacts survival outcomes in advanced gastric cancer (GC) patients. Here, we extended these previous findings by investigating another oncogenic cooperation, namely, the interplay between YAP, the TAZ paralogue, and p53. The molecular output of the YAP-p53 cooperation is dependent on TP53 mutational status. In the absence of mutations, the YAP-p53 crosstalk elicits a pro-apoptotic response, whereas in the presence of TP53 mutations it activates a pro-proliferative transcriptional program. In order to study this phenomenon, we re-analyzed data from 83 advanced GC patients treated with chemotherapy whose tissue samples had been characterized for YAP expression (immunohistochemistry, IHC) and TP53 mutations (deep sequencing). In doing so, we generated a molecular model combining nuclear YAP expression in association with TP53 missense variants (YAP+/TP53mut(mv)). Surprisingly, this signature was associated with a decreased risk of disease progression (multivariate Cox for progression-free survival: HR 0.53, 95% CI 0.30-0.91, p = 0.022). The YAP+/TP53mut(mv) model was also associated with better OS in the subgroup of patients who received chemotherapy beyond the first-line setting (multivariate Cox: HR 0.36, 95% CI 0.16-0.81, p = 0.013). Collectively, our findings suggest that the oncogenic cooperation between YAP and mutant p53 may translate into better survival outcomes. This apparent paradox can be explained by the pro-proliferative program triggered by YAP and mutant p53, that supposedly renders cancer cells more vulnerable to cytotoxic therapies. [ABSTRACT FROM AUTHOR]

There is growing evidence that 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) plays a role in breast cancer prevention and survival. It elicits a variety of antitumor activities like controlling cellular differentiation, proliferation and angiogenesis. Most of its biological effects are exerted via its nuclear receptor which acts as a transcriptional regulator. Here, we carried out a genome-wide investigation of the primary transcriptional targets of 1α,25(OH)2D3 in breast epithelial cancer cells using RNA-Seq technology. We identified early transcriptional targets of 1α,25(OH)2D3 involved in adhesion, growth regulation, angiogenesis, actin cytoskeleton regulation, hexose transport, inflammation and immunomodulation, apoptosis, endocytosis and signaling. Furthermore, we found several transcription factors to be regulated by 1α,25(OH)2D3 that subsequently amplify and diversify the transcriptional output driven by 1α,25(OH)2D3 leading finally to a growth arrest of the cells. Moreover, we could show that 1α,25(OH)2D3 elevates the trimethylation of histone H3 lysine 4 at several target gene promoters. Our present transcriptomic analysis of differential expression after 1α,25(OH)2D3 treatment provides a resource of primary 1α,25(OH)2D3 targets that might drive the antiproliferative action in breast cancer epithelial cells. [ABSTRACT FROM AUTHOR]