WASH and Tsg101/ALIX-dependent diversion of stress-internalized EGFR from the canonical endocytic pathway

Stress exposure triggers ligand-independent EGF receptor (EGFR) endocytosis, but its post-endocytic fate and role in regulating signalling are unclear. We show that the p38 MAP kinase-dependent, EGFR tyrosine kinase (TK)-independent EGFR internalization induced by ultraviolet light C (UVC) or the cancer therapeutic cisplatin, is followed by diversion from the canonical endocytic pathway. Instead of lysosomal degradation or plasma membrane recycling, EGFR accumulates in a subset of LBPA-rich perinuclear multivesicular bodies (MVBs) distinct from those carrying EGF-stimulated EGFR. Stress-internalized EGFR co-segregates with exogenously expressed pre-melanosomal markers OA1 and fibrillar PMEL, following early endosomal sorting by the actin polymerization-promoting WASH complex. Stress-internalized EGFR is retained intracellularly by continued p38 activity in a mechanism involving ubiquitin-independent, ESCRT/ALIX-dependent incorporation onto intraluminal vesicles (ILVs) of MVBs. In contrast to the internalization-independent EGF-stimulated activation, UVC/cisplatin-triggered EGFR activation depends on EGFR internalization and intracellular retention. EGFR signalling from this MVB subpopulation delays apoptosis and might contribute to chemoresistance

Time to endoscopic intervention in patients with upper gastrointestinal patients can be improved with pathway provision

BACKGROUND:Patients with upper gastrointestinal malignancy often require admission to hospital with dysphagia or jaundice requiring therapeutic endoscopy. Endoscopic intervention is often effective permitting rapid discharge. An efficient service would permit rapid discharge for patients who are often at the end of life. We noted that a majority of patients in hospital under the gastroenterological oncology were admitted with symptoms requiring therapeutic endoscopy. METHODS: We conducted an audit cycle of the inpatient days before and after pathway implementation. A wait of 1 day was set as acceptable for patients with bleeding as defined by NICE guidance and we set an arbitrary standard of 2 days for patients without bleeding but requiring therapeutic endoscopy. Between the audit cycles, a pathway was built to accommodate these patients. RESULTS: Inpatient waits improved from a median of 3 days to 1 day. There was no difference in outcome between those presenting with bleeding and other symptoms or any difference in patients requiring different procedures. CONCLUSIONS: Waiting times for endoscopy can be improved with the introduction of a targeted pathway of cancer patients. Further issues including cost, quality of life and nutrition require further intervention

MEK inhibition leads to BRCA2 downregulation and sensitization to DNA damaging agents in pancreas and ovarian cancer models

Targeting the DNA damage response (DDR) in tumors with defective DNA repair is a clinically successful strategy. The RAS/RAF/MEK/ERK signalling pathway is frequently deregulated in human cancers. In this study, we explored the effects of MEK inhibition on the homologous recombination pathway and explored the potential for combination therapy of MEK inhibitors with DDR inhibitors and a hypoxia-activated prodrug. We studied effects of combining pimasertib, a selective allosteric inhibitor of MEK1/2, with olaparib, a small molecule inhibitor of poly (adenosine diphosphate [ADP]-ribose) polymerases (PARP), and with the hypoxia-activated prodrug evofosfamide in ovarian and pancreatic cancer cell lines. Apoptosis was assessed by Caspase 3/7 assay and protein expression was detected by immunoblotting. DNA damage response was monitored with γH2AX and RAD51 immunofluorescence staining. In vivo antitumor activity of pimasertib with evofosfamide were assessed in pancreatic cancer xenografts. We found that BRCA2 protein expression was downregulated following pimasertib treatment under hypoxic conditions. This translated into reduced homologous recombination repair demonstrated by levels of RAD51 foci. MEK inhibition was sufficient to induce formation of γH2AX foci, suggesting that inhibition of this pathway would impair DNA repair. When combined with olaparib or evofosfamide, pimasertib treatment enhanced DNA damage and increased apoptosis. The combination of pimasertib with evofosfamide demonstrated increased anti-tumor activity in BRCA wild-type Mia-PaCa-2 xenograft model, but not in the BRCA mutated BxPC3 model. Our data suggest that targeted MEK inhibition leads to impaired homologous recombination DNA damage repair and increased PARP inhibition sensitivity in BRCA- 2 proficient cancers

Modulation of topoisomerase IIα expression and chemosensitivity through targeted inhibition of NF-Y:DNA binding by a diamino p-anisyl-benzimidazole (Hx) polyamide

BACKGROUND: Sequence specific polyamide HxIP 1, targeted to the inverted CCAAT Box 2 (ICB2) on the topoisomerase IIα (topo IIα) promoter can inhibit NF-Y binding, re-induce gene expression and increase sensitivity to etoposide. To enhance biological activity, diamino-containing derivatives (HxI*P 2 and HxIP* 3) were synthesised incorporating an alkyl amino group at the N1-heterocyclic position of the imidazole/pyrrole. METHODS: DNase I footprinting was used to evaluate DNA binding of the diamino Hx-polyamides, and their ability to disrupt the NF-Y:ICB2 interaction assessed using EMSAs. Topo IIα mRNA (RT-PCR) and protein (Immunoblotting) levels were measured following 18h polyamide treatment of confluent A549 cells. γH2AX was used as a marker for etoposide-induced DNA damage after pre-treatment with HxIP* 3 and cell viability was measured using Cell-Titer Glo®. RESULTS: Introduction of the N1-alkyl amino group reduced selectivity for the target sequence 5'-TACGAT-3' on the topo IIα promoter, but increased DNA binding affinity. Confocal microscopy revealed both fluorescent diamino polyamides localised in the nucleus, yet HxI*P 2 was unable to disrupt the NF-Y:ICB2 interaction and showed no effect against the downregulation of topo IIα. In contrast, inhibition of NF-Y binding by HxIP* 3 stimulated dose-dependent (0.1-2μM) re-induction of topo IIα and potentiated cytotoxicity of topo II poisons by enhancing DNA damage. CONCLUSIONS: Polyamide functionalisation at the N1-position offers a design strategy to improve drug-like properties. Dicationic HxIP* 3 increased topo IIα expression and chemosensitivity to topo II-targeting agents. GENERAL SIGNIFICANCE: Pharmacological modulation of topo IIα expression has the potential to enhance cellular sensitivity to clinically-used anticancer therapeutics. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani

Activity of the DNA minor groove cross-linking agent SG2000 (SJG-136) against canine tumours

BACKGROUND: Cancer is the leading cause of death in older dogs and its prevalence is increasing. There is clearly a need to develop more effective anti-cancer drugs in dogs. SG2000 (SJG-136) is a sequence selective DNA minor groove cross-linking agent. Based on its in vitro potency, the spectrum of in vivo and clinical activity against human tumours, and its tolerability in human patients, SG2000 has potential as a novel therapeutic against spontaneously occurring canine malignancies. RESULTS: In vitro cytotoxicity was assessed using SRB and MTT assays, and in vivo activity was assessed using canine tumour xenografts. DNA interstrand cross-linking (ICL) was determined using a modification of the single cell gel electrophoresis (comet) assay. Effects on cell cycle distribution were assessed by flow cytometry and measurement of γ-H2AX by immunofluorescence and immunohistochemistry. SG2000 had a multi-log differential cytotoxic profile against a panel of 12 canine tumour cell lines representing a range of common tumour types in dogs. In the CMeC-1 melanoma cell line, DNA ICLs increased linearly with dose following a 1 h treatment. Peak ICL was achieved within 1 h and no removal was observed over 48 h. A relationship between DNA ICL formation and cytotoxicity was observed across cell lines. The formation of γ-H2AX foci was slow, becoming evident after 4 h and reaching a peak at 24 h. SG2000 exhibited significant anti-tumour activity against two canine melanoma tumour models in vivo. Anti-tumour activity was observed at 0.15 and 0.3 mg/kg given i.v. either once, or weekly x 3. Dose-dependent DNA ICL was observed in tumours (and to a lower level in peripheral blood mononuclear cells) at 2 h and persisted at 24 h. ICL increased following the second and third doses in a repeated dose schedule. At 24 h, dose dependent γ-H2AX foci were more numerous than at 2 h, and greater in tumours than in peripheral blood mononuclear cells. SG2000-induced H2AX phosphorylation measured by immunohistochemistry showed good correspondence, but less sensitivity, than measurement of foci. CONCLUSIONS: SG2000 displayed potent activity in vitro against canine cancer cell lines as a result of the formation and persistence of DNA ICLs. SG2000 also had significant in vivo antitumour activity against canine melanoma xenografts, and the comet and γ-H2AX foci methods were relevant pharmacodynamic assays. The clinical testing of SG2000 against spontaneous canine cancer is warranted. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12917-015-0534-2) contains supplementary material, which is available to authorized users

Construction and validation of an developmental profile assessment tool for children with autistic spectrum disorder

Nos últimos anos a investigação tem dado particular relevância às alterações do Processamento Sensorial nas crianças com perturbações do espectro do autismo (PEA) e a literatura refere que entre 42% a 88% das crianças com PEA apresentam este tipo de disfunção. Nesta linha foi definido um projeto de investigação centrado na construção de uma escala que avalie a tradicional tríade que caracteriza as crianças com PEA (Interação, Comunicação e Comportamento e interesses repetitivos e estereotipados), enriquecida pela inclusão de um novo domínio: o Processamento Sensorial. Com a construção e validação desta escala pretendemos que pais e profissionais utilizem colaborativamente um instrumento de avaliação da intervenção que lhes permita monitorizar o processo de apoio e adequar as suas práticas. Neste artigo descrevemos os procedimentos e os resultados das sucessivas fases de construção do instrumento, desde as análises iniciais mais qualitativas até aos estudos centrados na análise quantitativa dos itens.During the last few years, research has focused on changes in Sensory Processing in children with Autistic Spectrum Disorder (ASD). As a result, literature has shown that between 42% and 88% of children with ASD present this type of disorder. Based on these findings, a research project was designed centring on the construction of a tool to assess the traditional triad that characterizes children with ASD (Interaction, Communication and Behaviour and Repetitive and Stereotyped Interests), to which was added a new domain: Sensory Processing. By constructing and validating this assessment tool, the intention is for parents and professionals to collaboratively apply this intervention assessment instrument in order to monitor the support process and adapt their practices. In this paper, we describe procedures and results of the successive stages entailed in constructing this instrument, from the first primarily qualitative analyses up to the studies centred on the quantitative item analysis.Fundação para a Ciência e Tecnologia (FCT)ABPEE - Associação Brasileira de Pesquisadores em Educação EspecialConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CAPESMinistério da Educação - BrasilMinistério da Ciência e da Tecnologia - BrasilGoverno Federal - Brasi

Multimodal Treatment in Metastatic Colorectal Cancer (mCRC) Improves Outcomes—The University College London Hospital (UCLH) Experience

Background: Despite notable advances in the management of metastatic colorectal cancer (mCRC) over the last two decades, treatment intent in the vast majority of patients remains palliative due to technically unresectable disease, extensive disease, or co-morbidities precluding major surgery. Up to 30% of individuals with mCRC are considered potentially suitable for primary or metastasis-directed multimodal therapy, including surgical resection, ablative techniques, or stereotactic radiotherapy (RT), with the aim of improving survival outcomes. We reviewed the potential benefits of multimodal therapy on the survival of patients with mCRC treated at the UCLH. Methods: Clinical data on baseline characteristics, multimodal treatments, and survival outcomes were retrospectively collected from all patients with mCRC receiving systemic chemotherapy between January 2013 and April 2017. Primary outcome was the impact of multimodal therapy on overall survival, compared to systemic therapy alone, and the effect of different types of multimodal therapy on survival outcome, and was assessed using the Kaplan–Meier approach. All analyses were adjusted for age, gender, and side of primary tumour. Results: One-hundred and twenty-five patients with mCRC were treated during the study period (median age: 62 years (range 19–89). The liver was the most frequent metastatic site (78%; 97/125). A total of 52% (65/125) had ≥2 lines of systemic chemotherapy. Of the 125 patients having systemic chemotherapy, 74 (59%) underwent multimodal treatment to the primary tumour or metastasis. Median overall survival (OS) was 25.7 months [95% Confidence Interval (CI) 21.5–29.0], and 3-year survival, 26%. Univariate analysis demonstrated that patients who had additional procedures (surgery/ablation/RT) were significantly less likely to die (Hazard Ratio (HR) 0.18, 95% CI 0.12–0.29, p < 0.0001) compared to those receiving systemic chemotherapy alone. Increasing number of multimodal procedures was associated with an incremental increase in survival—with median OS 28.4 m, 35.7 m, and 64.8 m, respectively, for 1, 2, or ≥3 procedures (log-rank p < 0.0001). After exclusion of those who received systemic chemotherapy only (n = 51), metastatic resections were associated with improved survival (adjusted HR 0.36, 95% CI 0.20–0.63, p < 0.0001), confirmed in multivariate analysis. Multiple single-organ procedures did not improve survival. Conclusion: Multimodal therapy for metastatic bowel cancer is associated with significant survival benefit. Resection/radical RT of the primary and resection of metastatic disease should be considered to improve survival outcomes following multidisciplinary team (MDT) discussion and individual assessment of fitness

Measurement of the critical DNA lesions produced by antibody-directed enzyme prodrug therapy (ADEPT) in vitro, in vivo and in clinical material

An antibody-directed enzyme prodrug therapy (ADEPT) system against CEA-positive tumours is currently in phase I clinical trials. It consists of a prodrug, 4-[N,N-bis(2-iodoethyl) amino] phenoxycarbonyl L -glutamic acid (ZD2767P) and a conjugate of the F(ab')2 anti-CEA antibody A5B7 and the bacterial enzyme carboxypeptidase G2 (CPG2). ZD2767P is converted by antibody-targeted CPG2 into an active bifunctional alkylating drug (ZD2767) at the tumour site. The IC 50 value of the prodrug against the human colorectal tumour LS174T cell line was 55 ± 9 μM following a 1 h exposure. In contrast, co-incubation of ZD2767P with CPG2 resulted in 229-fold increase in activity. Using a modified comet assay, DNA interstrand cross links (ISC) were detected within 1 h of ZD2767P + CPG2 treatment and were repaired by 24 h. A clear dose–response was seen between the level of ISC, growth inhibition and ZD2767 concentration. Administration of a therapeutic dose of ZD2767P 72 h after the F(ab′)2 A5B7 conjugate to mice bearing LS147T xenografts resulted in extensive ISC in the tumour after 1 h; repair was seen at 24 h. Tumour biopsies and peripheral lymphocytes were studied in 5 patients on the ADEPT phase I clinical trial. In 4 patients no ISC were detected. These patients also demonstrated poor localization of conjugate and no tumour response was seen. However a significant level of ISC was detected in one tumour biopsy, which also showed evidence of conjugate localization and clinical response. These studies demonstrate the application of the comet assay in the measurement of ISC in vitro and in clinical material and confirm that activation of ZD2767P results in the formation of DNA crosslinks. © 2001 Cancer Research Campaign http://www.bjcancer.co

Stress-specific p38 MAP kinase activation is sufficient to drive EGF receptor endocytosis but not nuclear translocation

EGF receptor (EGFR) endocytosis is induced by stress in a manner dependent on the p38 MAPK family. Ligand and stresses such as X-rays, reportedly promote nuclear trafficking of endocytosed EGFR for regulation of gene transcription and DNA repair. We fail to detect EGFR endocytosis or nuclear transport following X-ray treatment of HeLa or head and neck cancer cells, despite extensive DNA damage induction. Apparent nuclear staining with EGFR extracellular domain antibody remained present despite reduced/absent EGFR expression, and so did not represent nuclear EGFR. UVB and UVC, but not X-ray or UVA, treatment induced p38 activation and EGFR endocytosis, although all of these stresses induced DNA damage, indicating that DNA damage alone is not sufficient to induce EGFR endocytosis. Increased reactive oxygen species (ROS) levels following UVB treatment, compared to that seen with X-rays, do not alone explain differences in p38 activation. UVB, like UVC, induced EGFR accumulation predominantly in perinuclear endosomes, rather than in the nucleus. Our morphological techniques identifying major changes in receptor distribution do not exclude the possibility that small but biologically relevant amounts of EGFR enter the nucleus. This study highlights the importance and limitations of morphological analyses of receptor distribution in understanding signaling outcome

Doxorubicin-induced chronic dilated cardiomyopathy—the apoptosis hypothesis revisited

The chemotherapeutic agent doxorubicin (DOX) has significantly increased survival rates of pediatric and adult cancer patients. However, 10% of pediatric cancer survivors will 10–20 years later develop severe dilated cardiomyopathy (DCM), whereby the exact molecular mechanisms of disease progression after this long latency time remain puzzling. We here revisit the hypothesis that elevated apoptosis signaling or its increased likelihood after DOX exposure can lead to an impairment of cardiac function and cause a cardiac dilation. Based on recent literature evidence, we first argue why a dilated phenotype can occur when little apoptosis is detected. We then review findings suggesting that mature cardiomyocytes are protected against DOX-induced apoptosis downstream, but not upstream of mitochondrial outer membrane permeabilisation (MOMP). This lack of MOMP induction is proposed to alter the metabolic phenotype, induce hypertrophic remodeling, and lead to functional cardiac impairment even in the absence of cardiomyocyte apoptosis. We discuss findings that DOX exposure can lead to increased sensitivity to further cardiomyocyte apoptosis, which may cause a gradual loss in cardiomyocytes over time and a compensatory hypertrophic remodeling after treatment, potentially explaining the long lag time in disease onset. We finally note similarities between DOX-exposed cardiomyocytes and apoptosis-primed cancer cells and propose computational system biology as a tool to predict patient individual DOX doses. In conclusion, combining recent findings in rodent hearts and cardiomyocytes exposed to DOX with insights from apoptosis signal transduction allowed us to obtain a molecularly deeper insight in this delayed and still enigmatic pathology of DC