Carcinoid Crisis: A Misunderstood and Unrecognized Oncological Emergency

Carcinoid Crisis represents a rare and extremely dangerous manifestation that can occur in patients with Neuroendocrine Tumors (NETs). It is characterized by a sudden onset of hemodynamic instability, sometimes associated with the classical symptoms of carcinoid syndrome, such as bronchospasm and flushing. Carcinoid Crisis seems to be caused by a massive release of vasoactive substances, typically produced by neuroendocrine cells, and can emerge after abdominal procedures, but also spontaneously in rare instances. To date, there are no empirically derived guidelines for the management of this cancer-related medical emergency, and the available evidence essentially comes from single-case reports or dated small retrospective series. A transfer to the Intensive Care Unit may be necessary during the acute setting, when the severe hypotension becomes unresponsive to standard practices, such as volemic filling and the infusion of vasopressor therapy. The only effective strategy is represented by prevention. The administration of octreotide, anxiolytic and antihistaminic agents represents the current treatment approach to avoid hormone release and prevent major complications. However, no standard protocols are available, resulting in great variability in terms of schedules, doses, ways of administration and timing of prophylactic treatments

Postsorafenib systemic treatments for hepatocellular carcinoma: questions and opportunities after the regorafenib trial.

The search for systemic therapies for hepatocellular carcinoma has been characterized by difficulties and failures. Despite recent progresses, many issues are still to be settled. In particular, the development of drugs inhibiting different neoplastic pathways remains a priority for patients intolerant or resistant to antiangiogenic drugs. This task may be daunting, as previous failures extensively demonstrated. We aimed to identify the future perspective of postsorafenib trials analyzing the strengths and the critical points of past and currently undergoing studies, in the light of the most recent evidences in the field. We identified various points (including stratification, biomarkers, end points, radiologic criteria of response, treatment beyond radiologic progression) that should be considered by future trials to reduce the risks of failure

Deficient DNA base-excision repair in the forebrain leads to a sex-specific anxiety-like phenotype in mice

Background: Neuropsychiatric disorders, such as schizophrenia (SZ) and autism spectrum disorder (ASD), are common, multi-factorial and multi-symptomatic disorders. Ample evidence implicates oxidative stress, deficient repair of oxidative DNA lesions and DNA damage in the development of these disorders. However, it remains unclear whether insufficient DNA repair and resulting DNA damage are causally connected to their aetiopathology, or if increased levels of DNA damage observed in patient tissues merely accumulate as a consequence of cellular dysfunction. To assess a potential causal role for deficient DNA repair in the development of these disorders, we behaviourally characterized a mouse model in which CaMKIIa-Cre-driven postnatal conditional knockout (KO) of the core base-excision repair (BER) protein XRCC1 leads to accumulation of unrepaired DNA damage in the forebrain. Results: CaMKIIa-Cre expression caused specific deletion of XRCC1 in the dorsal dentate gyrus (DG), CA1 and CA2 and the amygdala and led to increased DNA damage therein. While motor coordination, cognition and social behaviour remained unchanged, XRCC1 KO in the forebrain caused increased anxiety-like behaviour in males, but not females, as assessed by the light–dark box and open field tests. Conversely, in females but not males, XRCC1 KO caused an increase in learned fear-related behaviour in a cued (Pavlovian) fear conditioning test and a contextual fear extinction test. The relative density of the GABA(A) receptor alpha 5 subunit (GABRA5) was reduced in the amygdala and the dorsal CA1 in XRCC1 KO females, whereas male XRCC1 KO animals exhibited a significant reduction of GABRA5 density in the CA3. Finally, assessment of fast-spiking, parvalbumin-positive (PV) GABAergic interneurons revealed a significant increase in the density of PV+ cells in the DG of male XRCC1 KO mice, while females remained unchanged. Conclusions: Our results suggest that accumulation of unrepaired DNA damage in the forebrain alters the GABAergic neurotransmitter system and causes behavioural deficits in relation to innate and learned anxiety in a sex-dependent manner. Moreover, the data uncover a previously unappreciated connection between BER deficiency, unrepaired DNA damage in the hippocampus and a sex-specific anxiety-like phenotype with implications for the aetiology and therapy of neuropsychiatric disorders

“Open Sesame?”: biomarker status of the human equilibrative nucleoside transporter-1 and molecular mechanisms influencing its expression and activity in the uptake and cytotoxicity of gemcitabine in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive tumor characterized by early invasiveness, rapid progression and resistance to treatment. Gemcitabine has been for more than twenty years the main therapy for PDAC both in the palliative and adjuvant setting. After the introduction of FOLFIRINOX as upfront treatment for metastatic disease, gemcitabine is still commonly used in combination with nab-paclitaxel as an alternative first-line regimen, as well as a monotherapy in elderly patients unfit for combination chemotherapy. As a hydrophilic nucleoside analogue, gemcitabine requires nucleoside transporters to permeate the plasma membrane, and a major role in the uptake of this drug is played by human equilibrative nucleoside transporter 1 (hENT-1). Several studies have proposed hENT-1 as a biomarker for gemcitabine efficacy in PDAC. A recent comprehensive multimodal analysis of hENT-1 status evaluated its predictive role by both immunohistochemistry (with five different antibodies), and quantitative-PCR, supporting the use of the 10D7G2 antibody. High hENT-1 levels observed with this antibody were associated with prolonged disease-free and overall-survival in patients receiving gemcitabine adjuvant chemotherapy. We discuss this analysis and lists molecular factors influencing hENT-1. Improved knowledge on these factors should help in the identification of subgroups of patients who may benefit from specific therapies and overcome the limitations of traditional biomarker studies

Substrate specificity and regioselectivity of fungal AA9 lytic polysaccharide monooxygenases secreted by Podospora anserina

International audienceBackground: The understanding of enzymatic polysaccharide degradation has progressed intensely in the past few years with the identification of a new class of fungal-secreted enzymes, the lytic polysaccharide monooxygenases (LPMOs) that enhance cellulose conversion. In the fungal kingdom, saprotrophic fungi display a high number of genes encoding LPMOs from family AA9 but the functional relevance of this redundancy is not fully understood. Results: In this study, we investigated a set of AA9 LPMOs identified in the secretomes of the coprophilous ascomycete Podospora anserina, a biomass degrader of recalcitrant substrates. Their activity was assayed on cellulose in synergy with the cellobiose dehydrogenase from the same organism. We showed that the total release of oxidized oligosaccharides from cellulose was higher for PaLPMO9A, PaLPMO9E, and PaLPMO9H that harbored a carbohydrate-binding module from the family CBM1. Investigation of their regioselective mode of action revealed that PaLPMO9A and PaLPMO9H oxidatively cleaved at both C1 and C4 positions while PaLPMO9E released only C1-oxidized products. Rapid cleavage of cellulose was observed using PaLPMO9H that was the most versatile in terms of substrate specificity as it also displayed activity on cello-oligosaccharides and beta-(1,4)-linked hemicellulose polysaccharides (e.g., xyloglucan, glucomannan). Conclusions: This study provides insights into the mode of cleavage and substrate specificities of fungal AA9 LPMOs that will facilitate their application for the development of future biorefineries

Synchronous and metachronous colorectal liver metastases: Impact of primary tumor location on patterns of recurrence and survival after hepatic resection

Background: Considerable differences in terms of prognosis exist between the right-sided (RCC) and the left-sided colon cancer (LCC). Aim of the work: In this study, we evaluated prognostic implications of primary tumor location (PTL) among patients who underwent curative-intent hepatectomy for synchronous (SM) and metachronous (MM) colorectal liver metastases (CRLM). Methods: The study population included all consecutive patients affected by CRLM scheduled for first liver resection at three Italian oncological centers. Results: A total of 204 patients who underwent CRLM resection were included, 50% with RCC. Synchronous lesions were prevalent (n=133, 65%). Median OS was respectively 40.3 months for SM-RCC, 53.5 months for SM-LCC, 64.5 months for MM-RCC and 81.6 months for MM-LCC. Patients with MM-LCC showed an OS better than patients with SM-RCC (p=0.008) and SM-LCC (p=0.002). PTL had no influence on RFS. RCC group had less recurrences (75% vs 86.5%), though further surgery with curative-intent was possible more in LCC group (29.3% vs 32.5%). Cox proportional hazards model analysis showed that age and the presence of SM vs MM was associated with a significantly higher hazard ratio (HR) for death (HR=1.024; 95%CI=1.005-1.043; p=0.011 and HR=2.010; 95%CI=1.328-3.043; p=0.001, respectively). Conclusions: We confirmed that patients with CRLM and right-sided primary colon cancer experience worse survival after hepatic resection. The timing of metastasis has been revealed as important prognostic factor

Structural characterization of the Pet c 1.0201 PR-10 protein isolated from roots of Petroselinum crispum (Mill.) Fuss

The native dimeric Petroselinum crispum (Mill.) Fuss protein Pet c 1.0201 and a monomeric xyloglucan endotransglycosylase enzyme (Garajova et al., 2008) isolated from the root cells co-purify and share similar molecular masses and acidic isoelectric points. In this work, we determined the complete primary structure of the parsley Pet c 1.0201 protein, based on tryptic and chymotryptic peptides followed by the manual micro-gradient chromatographic separation coupled with offline MALDI-TOF/TOF mass spectrometry. The bioinformatics approach enabled us to include the parsley protein into the PR-10 family, as it exhibited the highest protein sequence identity with the Apium graveolens Api g 1.0201 allergen and the major Daucus carota allergen Dau c 1.0201. Hence, we designated the Petroselinum crispum protein as Pet c 1.0201 and deposited it in the UniProt Knowledgebase under the accession C0HKF5. 3D protein homology modelling and molecular dynamics simulations of the Pet c 1.0201 dimer confirmed the typical structure of the Bet v 1 family allergens, and the potential of the Pet c 1.0201 protein to dimerize in water. However, the behavioural properties of Pet c 1.0201 and the celery allergen Api g 1.0101 differed in the presence of salts due to transiently and stably formed dimeric forms of Pet c 1.0201 and Api g 1.0101, respectively.Barbora Stratilová, Pavel Řehulka, Soňa Garajová, Helena Řehulková, Eva Stratilová, Maria Hrmova, Stanislav Kozmo

MicroRNA expression profiling with a droplet digital PCR assay enables molecular diagnosis and prognosis of cancers of unknown primary

Metastasis is responsible for the majority of cancer‐related deaths. Particularly, challenging is the management of metastatic cancer of unknown primary site (CUP), whose tissue of origin (TOO) remains undetermined even after extensive investigations and whose therapy is rather unspecific and poorly effective. Molecular approaches to identify the most probable TOO of CUPs can overcome some of these issues. In this study, we applied a predetermined set of 89 microRNAs (miRNAs) to infer the TOO of 53 metastatic cancers of unknown or uncertain origin. The miRNA expression was assessed with droplet digital PCR in 159 samples, including primary tumors from 17 tumor classes (reference set) and metastases of known and unknown origin (test set). We combined two different statistical models for class prediction to obtain the most probable TOOs: the nearest shrunken centroids approach of Prediction Analysis of Microarrays (PAMR) and the least absolute shrinkage and selection operator (LASSO) models. The molecular test was successful for all formalin‐fixed paraffin‐embedded samples and provided a TOO identification within 1 week from the biopsy procedure. The most frequently predicted origins were gastrointestinal, pancreas, breast, lung, and bile duct. The assay was applied also to multiple metastases from the same CUP, collected from different metastatic sites: The predictions showed a strong agreement, intrinsically validating our assay. The final CUPs' TOO prediction was compared with the clinicopathological hypothesis of primary site. Moreover, a panel of 13 miRNAs proved to have prognostic value and be associated with overall survival in CUP patients. Our study demonstrated that miRNA expression profiling in CUP samples could be employed as diagnostic and prognostic test. Our molecular analysis can be performed on request, concomitantly with standard diagnostic workup and in association with genetic profiling, to offer valuable indications about the possible primary site, thereby supporting treatment decisions

Another building block in the plant cell wall: Barley xyloglucan xyloglucosyl transferases link covalently xyloglucan and anionic oligosaccharides derived from pectin

Published online 16 August 2020.We report on the homo‐ and hetero‐transglycosylation activities of the HvXET3 and HvXET4 xyloglucan xyloglucosyl transferases (XET; EC 2.4.1.207) from barley (Hordeum vulgare L.), and the visualisation of these activities in young barley roots using Alexa Fluor 488‐labelled oligosaccharides. We discover that these isozymes catalyse the transglycosylation reactions with the chemically defined donor and acceptor substrates, specifically with the xyloglucan donor and the penta‐galacturonide [α(1‐4)GalAp]5 acceptor – the homogalacturonan (pectin) fragment. This activity is supported by 3D molecular models of HvXET3 and HvXET4 with the docked XXXG donor and [α(1‐4)GalAp]5 acceptor substrates at the ‐4 to +5 subsites in the active sites. Comparative sequence analyses of barley isoforms and seed‐localised TmXET6.3 from nasturtium (Tropaeolum majus L.) permitted the engineering of mutants of TmXET6.3 that could catalyse the hetero‐transglycosylation reaction with the xyloglucan/[α(1‐4)GalAp]5 substrate pair, while wild‐type TmXET6.3 lacked this activity. Expression data obtained by real‐time quantitative PCR of HvXET transcripts and a clustered heatmap of expression profiles of the gene family revealed that HvXET3 and HvXET6 co‐expressed but did not share the monophyletic origin. Conversely, HvXET3 and HvXET4 shared this relationship, when we examined the evolutionary history of 419 glycoside hydrolase 16 family members, spanning monocots, eudicots, and a basal Angiosperm. The discovered hetero‐transglycosylation activity in HvXET3 and HvXET4 with the xyloglucan/[α(1‐4)GalAp]5 substrate pair is discussed against the background of roles of xyloglucan‐pectin heteropolymers and how they may participate in spatial patterns of cell wall formation and re‐modelling, and affect the structural features of walls.Barbora Stratilová, Sergej Šesták, Jozef Mravec, Soňa Garajová, Zuzana Pakanová, Kristína Vadinová, Danica Kučerová, Stanislav Kozmon, Julian G. Schwerdt, Neil Shirley Eva Stratilová and Maria Hrmov