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James Bond is trapped in Los Angeles, under fire alongside another MI6 agent with a foreign intelligence services - or perhaps more than just one - trying to put them in body bags. Things may not be any safer in Britain, with bodies dropping and ghosts moving in the political mist.

Multiple studies in recent years have identified highly tumorigenic populations of cells that drive tumor formation. These cancer stem cells (CSCs), or tumor-initiating cells (TICs), exhibit properties of normal stem cells and are associated with resistance to current therapies. As pancreatic adenocarcinoma is among the most resistant human cancers to chemo-radiation therapy, we sought to evaluate the presence of cell populations with tumor-initiating capacities in human pancreatic tumors. Understanding which pancreatic cancer cell populations possess tumor-initiating capabilities is critical to characterizing and understanding the biology of pancreatic CSCs towards therapeutic ends. We have isolated populations of cells with high ALDH activity (ALDH(high)) and/or CD133 cell surface expression from human xenograft tumors established from multiple patient tumors with pancreatic adenocarcinoma (direct xenograft tumors) and from the pancreatic cancer cell line L3.6pl. Through fluorescent activated cell sorting (FACs)-mediated enrichment and depletion of selected pancreatic cancer cell populations, we sought to discriminate the relative tumorigenicity of cell populations that express the pancreatic CSC markers CD133 and aldehyde dehydrogenase (ALDH). ALDH(high) and ALDH(low) cell populations were further examined for co-expression of CD44 and/or CD24. We demonstrate that unlike cell populations demonstrating low ALDH activity, as few as 100 cells enriched for high ALDH activity were capable of tumor formation, irrespective of CD133 expression. In direct xenograft tumors, the proportions of total tumor cells expressing ALDH and/or CD133 in xenograft tumors were unchanged through a minimum of two passages. We further demonstrate that ALDH expression among patients with pancreatic adenocarcinoma is heterogeneous, but the expression is constant in serial generations of individual direct xenograft tumors established from bulk human pancreatic tumors in NOD/SCID mice. We conclude that, in contrast to some previous studies, cell populations enriched for high ALDH activity alone are sufficient for efficient tumor-initiation with enhanced tumorigenic potential relative to CD133(+) and ALDH(low) cell populations in some direct xenograft tumors. Although cell populations enriched for CD133 expression may alone possess tumorigenic potential, they are significantly less tumorigenic than ALDH(high) cell populations. ALDH(high)/CD44(+)/CD24(+) or ALDH(low)/CD44(+)/CD24(+) phenotypes do not appear to significantly contribute to tumor formation at low numbers of inoculated tumor cells. ALDH expression broadly varies among patients with pancreatic adenocarcinoma and the apparent expression is recapitulated in serial generations of direct xenograft tumors in NOD/SCID. We have thus identified a distinct population of TICs that should lead to identification of novel targets for pancreatic cancer therapy.

To date, the most immunotherapy drugs act upon T cell surface proteins to promote tumoricidal T cell activity. However, this approach has to date been unsuccessful in certain solid tumor types including pancreatic, prostate cancer and glioblastoma. Myeloid-related innate immunity can promote tumor progression through direct and indirect effects on T cell activity; improved understanding of this field may provide another therapeutic avenue for patients with these tumors. Myeloid cells can differentiate into both pro-inflammatory and anti-inflammatory mature form depending upon the microenvironment. Most cancer type exhibit oncogenic activating point mutations (ex. P53 and KRAS) that trigger cytokines production. In addition, tumor environment (ex. Collagen, Hypoxia, and adenosine) also regulated inflammatory signaling cascade. Both the intrinsic and extrinsic factor driving the tumor immune microenvironment and regulating the differentiation and function of myeloid cells, T cells activity and tumor progression. In this review, we will discuss the relationship between cancer cells and myeloid cells-mediated tumor immune microenvironment to promote cancer progression and immunotherapeutic resistance. Furthermore, we will describe how cytokines and chemokines produced by cancer cells influence myeloid cells within immunosuppressive environment. Finally, we will comment on the development of immunotherapeutic strategies with respect to myeloid-related innate immunity.

Tensin 1 was originally described as a focal adhesion adaptor protein, playing a role in extracellular matrix and cytoskeletal interactions. Three other Tensin proteins were subsequently discovered, and the family was grouped as Tensin. It is now recognized that these proteins interact with multiple cell signalling cascades that are implicated in tumorigenesis. To understand the role of Tensin 1–3 in neoplasia, current molecular evidence is categorized by the hallmarks of cancer model. Additionally, clinical data involving Tensin 1–3 are reviewed to investigate the correlation between cellular effects and clinical phenotype. Tensin proteins commonly interact with the tumour suppressor, DLC1. The ability of Tensin to promote tumour progression is directly correlated with DLC1 expression. Members of the Tensin family appear to have tumour subtype‐dependent effects on oncogenesis; despite numerous data evidencing a tumour suppressor role for Tensin 2, association of Tensins 1–3 with an oncogenic role notably in colorectal carcinoma and pancreatic ductal adenocarcinoma is of potential clinical relevance. The complex interplay between these focal adhesion adaptor proteins and signalling pathways are discussed to provide an up to date review of their role in cancer biology.

Pancreatic cancers use a novel glutamine metabolism pathway, regulated by oncogenic KRAS, to maintain redox balance; these findings add to the understanding of the mechanisms by which oncogenic alterations reprogram cellular metabolism to promote tumour growth. Novel glutamine pathway in pancreatic cancer Pancreatic tumours often carry activating KRAS mutations. This study describes a novel KRAS-regulated pathway that is critical to the metabolism of glutamine by human pancreatic cancer cells and is required for tumour growth. The pathway appears to maintain redox homeostasis but is dispensable in normal cells, providing a possible avenue for pursuing antitumour compounds that might act in pancreatic ductal adenocarcinoma, an extremely aggressive cancer that is highly refractory to chemotherapy, radiation and targeted therapies. Cancer cells have metabolic dependencies that distinguish them from their normal counterparts 1 . Among these dependencies is an increased use of the amino acid glutamine to fuel anabolic processes 2 . Indeed, the spectrum of glutamine-dependent tumours and the mechanisms whereby glutamine supports cancer metabolism remain areas of active investigation. Here we report the identification of a non-canonical pathway of glutamine use in human pancreatic ductal adenocarcinoma (PDAC) cells that is required for tumour growth. Whereas most cells use glutamate dehydrogenase (GLUD1) to convert glutamine-derived glutamate into α-ketoglutarate in the mitochondria to fuel the tricarboxylic acid cycle, PDAC relies on a distinct pathway in which glutamine-derived aspartate is transported into the cytoplasm where it can be converted into oxaloacetate by aspartate transaminase (GOT1). Subsequently, this oxaloacetate is converted into malate and then pyruvate, ostensibly increasing the NADPH/NADP + ratio which can potentially maintain the cellular redox state. Importantly, PDAC cells are strongly dependent on this series of reactions, as glutamine deprivation or genetic inhibition of any enzyme in this pathway leads to an increase in reactive oxygen species and a reduction in reduced glutathione. Moreover, knockdown of any component enzyme in this series of reactions also results in a pronounced suppression of PDAC growth in vitro and in vivo . Furthermore, we establish that the reprogramming of glutamine metabolism is mediated by oncogenic KRAS, the signature genetic alteration in PDAC, through the transcriptional upregulation and repression of key metabolic enzymes in this pathway. The essentiality of this pathway in PDAC and the fact that it is dispensable in normal cells may provide novel therapeutic approaches to treat these refractory tumours.

KRAS mutations are a driver event of pancreatic ductal adenocarcinoma; here, a subpopulation of dormant tumour cells, relying on oxidative phosphorylation for survival, is shown to be responsible for tumour relapse after treatment targeting the KRAS pathway. Respiration-dependent cancer stem cells KRAS mutations represent a driver event of pancreatic ductal adenocarcinoma. Targeting this pathway leads to tumour regression, but the frequency of relapse indicates that a fraction of tumour cells survives even in the absence of oncogenic signalling. Using a Kras /p53 mouse model of pancreatic cancer, in which the expression of oncogenic Kras can be switched off, Giulio Draetta and colleagues show that the subpopulation of dormant tumour cells that survives oncogene ablation and is responsible for tumour relapse is dependent on oxidative phosphorylation (OXPHOS) for survival. These cells show high sensitivity to OXPHOS inhibitors, which can inhibit tumour recurrence, suggesting that combined targeting of the KRAS pathway and mitochondrial respiration might be effective in the treatment of pancreatic cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in western countries, with a median survival of 6 months and an extremely low percentage of long-term surviving patients. KRAS mutations are known to be a driver event of PDAC 1 , but targeting mutant KRAS has proved challenging 2 . Targeting oncogene-driven signalling pathways is a clinically validated approach for several devastating diseases 3 , 4 . Still, despite marked tumour shrinkage, the frequency of relapse indicates that a fraction of tumour cells survives shut down of oncogenic signalling 5 , 6 . Here we explore the role of mutant KRAS in PDAC maintenance using a recently developed inducible mouse model of mutated Kras 1 ( Kras G12D , herein KRas) in a p53 LoxP/WT background. We demonstrate that a subpopulation of dormant tumour cells surviving oncogene ablation (surviving cells) and responsible for tumour relapse has features of cancer stem cells and relies on oxidative phosphorylation for survival. Transcriptomic and metabolic analyses of surviving cells reveal prominent expression of genes governing mitochondrial function, autophagy and lysosome activity, as well as a strong reliance on mitochondrial respiration and a decreased dependence on glycolysis for cellular energetics. Accordingly, surviving cells show high sensitivity to oxidative phosphorylation inhibitors, which can inhibit tumour recurrence. Our integrated analyses illuminate a therapeutic strategy of combined targeting of the KRAS pathway and mitochondrial respiration to manage pancreatic cancer.

Aim Non-surgical treatment for head and neck cancer (HNC) often results in severe toxicities, which are detrimental to a patient’s health and quality of life. There is limited published UK data on unplanned hospital admissions and reasons associated with admission. We aim to identify frequencies and reasons for unplanned hospital admissions, highlighting those patient groups who are most vulnerable. Methods A retrospective study of unplanned hospital admissions of HNC patients receiving non-surgical treatment was completed. An inpatient admission was defined as ≥ 1 night spent in the hospital. To test potential demographic and treatment predictors of inpatient admission, a multiple regression model was constructed using the endpoint measure (unplanned admission), as the dependent variable. Results A cohort of 216 patients was identified over a 7-month period, and 38 of these patients (17%) required an unplanned admission. Treatment type was the only statistically significant predictor of in-patient admission. The majority of admissions were patients receiving chemoradiotherapy (CRT) (58%) with predominant reasons for admission being nausea and vomiting (25.5%) and decreased oral intake/dehydration (30%). Of the patients admitted, 12 had a prophylactic PEG placed pre-treatment, and 18 of 26 admitted without prophylactic PEG required nasogastric tube feeding during their admission. Discussion Almost one-fifth of HNC patients over this time period required hospital admission; the majority of which can be attributed to treatment toxicities when receiving CRT. This is concurrent with other studies which review the impact of radiotherapy versus CRT. Increased support and monitoring, particularly focused on nutrition, are required for patients with HNC who receive CRT. Key message This article describes a retrospective review of a patient undergoing non-surgical treatment for head and neck cancer. These patients frequently require unplanned hospital admission. The results indicate that patients undergoing (chemo)radiotherapy are most vulnerable to deterioration and additional support focused on nutrition for these patients is indicated.

BackgroundUpfront surgery is the current standard for resectable intrahepatic cholangiocarcinoma (ICC) despite high treatment failure with this approach. We sought to examine the use of neoadjuvant chemotherapy (NAC) as an alternative strategy for this population.MethodsThe National Cancer Database was used to identify patients with resectable ICC undergoing curative-intent surgery (2006–2014). Utilization trends were examined and survival estimates between NAC and upfront surgery were compared; propensity score-matched models were used to examine the association of NAC with overall survival (OS) for all patients and risk-stratified cohorts. Models accounted for clustering within hospitals, and results represent findings from a complete-case analysis.ResultsAmong 881 patients with ICC, 8.3% received NAC, with no changes over time (Cochran–Armitage p = 0.7). Median follow-up was 50.9 months, with no difference in unadjusted survival with NAC versus upfront surgery (median OS 51.8 vs. 35.6 months, and 5-year OS rates of 38.2% vs. 36.6%; log rank p = 0.51), and no survival benefit in the propensity score-matched analysis (hazard ratio [HR] 0.78, 95% CI 0.54–1.11; p = 0.16). However, for patients with stage II–III disease, NAC was associated with a trend towards improved survival (median OS of 47.6 months vs. 25.9 months, and 5-year OS rates of 34% vs. 25.7%; log-rank p = 0.10) and a statistically significant survival benefit in the propensity score-matched analysis. (HR 0.58, 95% CI 0.37–0.91; p = 0.02).ConclusionNAC is associated with improved OS over upfront surgery in patients with resectable ICC and high-risk of treatment failure. These data support the need for prospective studies to examine NAC as an alternative strategy to improve OS in this population.

The aim of this study is to determine the efficacy of neoadjuvant chemotherapy (NAC) with gemcitabine (GEM) in combination with fluorescence-guided surgery (FGS) on a pancreatic cancer patient derived orthotopic xenograft (PDOX) model. A PDOX model was established from a CA19-9-positive, CEA-negative tumor from a patient who had undergone a pancreaticoduodenectomy for pancreatic adenocarcinoma. Mice were randomized to 4 groups: bright light surgery (BLS) only; BLS+NAC; FGS only; and FGS+NAC. An anti-CA19-9 or anti-CEA antibody conjugated to DyLight 650 was administered intravenously via the tail vein of mice with the pancreatic cancer PDOX 24 hours before surgery. The PDOX was brightly labeled with fluorophore-conjugated anti-CA19-9, but not with a fluorophore-conjugated anti-CEA antibody. FGS was performed using the fluorophore-conjugated anti-CA19-9 antibody. FGS had no benefit over BLS to prevent metastatic recurrence. NAC in combination with BLS did not convey an advantage over BLS to prevent metastatic recurrence. However, FGS+NAC significantly reduced the metastatic recurrence frequency to one of 8 mice, compared to FGS only after which metastasis recurred in 6 out of 8 mice, and BLS+NAC with metastatic recurrence in 7 out of 8 mice (p = 0.041). Thus NAC in combination with FGS can reduce or even eliminate metastatic recurrence of pancreatic cancer sensitive to NAC. The present study further emphasizes the power of the PDOX model which enables metastasis to occur and thereby identify the efficacy of NAC in combination with FGS on metastatic recurrence.

Argininosuccinate synthetase 1 (ASS1), the rate-limiting enzyme for arginine biosynthesis, is expressed in many types of human malignancies. Recent studies showed that ASS1 may have tumor suppressor function and that ASS1 deficiency is associated with clinical aggressiveness in nasopharyngeal carcinoma, myxofibrosarcomas and bladder cancer. The goal of this study was to evaluate the prognostic impact of ASS1 expression in patients with pancreatic ductal adenocarcinoma (PDAC). Our study included two independent cohorts: untreated cohort, which was comprised of 135 patients with PDAC who underwent pancreatoduodenectomy (PD) without pre-operative neoadjuvant therapy, and treated cohort, which was comprised of 122 patients with PDAC who have completed neoadjuvant therapy and PD. The expression level of ASS1 was evaluated by immunohistochemistry and the results were correlated with clinicopathologic parameters and survival using SPSS statistics. Our study showed that 12% of PDAC in untreated cohort and 15% of PDAC in treated cohort has low expression of ASS1 (ASS1-low). ASS1-low was associated with higher recurrence (p = 0.045), shorter disease-free survival (DFS, 4.8 ± 1.6 months vs 15.3 ± 2.2 months, p = 0.001) and shorter overall survival (OS, 14.6 ± 6.4 months vs 26.5 ± 3.5 months, p = 0.005) in untreated cohort and shorter OS in treated cohort compared to ASS1-high tumors. In multivariate analysis, ASS1-low (HR: 0.45, 95% CI: 0.26-0.79, p = 0.005) was an independent prognostic factor for DFS in untreated cohort and an independent prognostic factor for OS (HR: 0.56, 95% CI: 0.32-0.97, p = 0.04) in treated cohort. Our results provide supporting evidence for future clinical trial using arginine deprivation agents either alone or in combination with conventional chemotherapy in treating pancreatic cancer.