Treatment of HCC with claudin-1-specific antibodies suppresses carcinogenic signaling and reprograms the tumor microenvironment.

BACKGROUND & AIMS: Despite recent approvals, the response to treatment and prognosis of patients with advanced hepatocellular carcinoma (HCC) remain poor. Claudin-1 (CLDN1) is a membrane protein that is expressed at tight junctions, but it can also be exposed non-junctionally, such as on the basolateral membrane of the human hepatocyte. While CLDN1 within tight junctions is well characterized, the role of non-junctional CLDN1 and its role as a therapeutic target in HCC remains unexplored. METHODS: Using humanized monoclonal antibodies (mAbs) specifically targeting the extracellular loop of human non-junctional CLDN1 and a large series of patient-derived cell-based and animal model systems we aimed to investigate the role of CLDN1 as a therapeutic target for HCC. RESULTS: Targeting non-junctional CLDN1 markedly suppressed tumor growth and invasion in cell line-based models of HCC and patient-derived 3D ex vivo models. Moreover, the robust effect on tumor growth was confirmed in vivo in a large series of cell line-derived xenograft and patient-derived xenograft mouse models. Mechanistic studies, including single-cell RNA sequencing of multicellular patient HCC tumorspheres, suggested that CLDN1 regulates tumor stemness, metabolism, oncogenic signaling and perturbs the tumor immune microenvironment. CONCLUSIONS: Our results provide the rationale for targeting CLDN1 in HCC and pave the way for the clinical development of CLDN1-specific mAbs for the treatment of advanced HCC. IMPACT AND IMPLICATIONS: Hepatocellular carcinoma (HCC) is associated with high mortality and unsatisfactory treatment options. Herein, we identified the cell surface protein Claudin-1 as a treatment target for advanced HCC. Monoclonal antibodies targeting Claudin-1 inhibit tumor growth in patient-derived ex vivo and in vivo models by modulating signaling, cell stemness and the tumor immune microenvironment. Given the differentiated mechanism of action, the identification of Claudin-1 as a novel therapeutic target for HCC provides an opportunity to break the plateau of limited treatment response. The results of this preclinical study pave the way for the clinical development of Claudin-1-specific antibodies for the treatment of advanced HCC. It is therefore of key impact for physicians, scientists and drug developers in the field of liver cancer and gastrointestinal oncology.

Hetero-Diels-Alder click reaction of dithioesters for a catalyst-free indirect 18F-radiolabelling of peptides.

The HDA reaction of dithioesters was developed as a new click-reaction compatible with the indirect 18F-labelling of peptides. It involves dithioester-peptides and a radiofluorinated diene as a novel prosthetic group. The method was applied to a PSMA-ligand for the in vivo detection of LNCap tumors in xenografted mice.

Basic Substances, a Sustainable Tool to Complement and Eventually Replace Synthetic Pesticides in the Management of Pre and Postharvest Diseases: Reviewed Instructions for Users.

Synthetic pesticides are widely used to protect crops from pathogens and pests, especially for fruits and vegetables, and this may lead to the presence of residues on fresh produce. Improving the sustainability of agriculture and, at the same time, reducing the adverse effects of synthetic pesticides on human health requires effective alternatives that improve the productivity while maintaining the food quality and safety. Moreover, retailers increasingly request fresh produce with the amounts of pesticides largely below the official maximum residue levels. Basic substances are relatively novel compounds that can be used in plant protection without neurotoxic or immune-toxic effects and are still poorly known by phytosanitary consultants (plant doctors), researchers, growers, consumers, and decision makers. The focus of this review is to provide updated information about 24 basic substances currently approved in the EU and to summarize in a single document their properties and instructions for users. Most of these substances have a fungicidal activity (calcium hydroxide, chitosan, chitosan hydrochloride, Equisetum arvense L., hydrogen peroxide, lecithins, cow milk, mustard seed powder, Salix spp., sunflower oil, sodium chloride, sodium hydrogen carbonate, Urtica spp., vinegar, and whey). Considering the increasing requests from consumers of fruits and vegetables for high quality with no or a reduced amount of pesticide residues, basic substances can complement and, at times, replace the application of synthetic pesticides with benefits for users and for consumers. Large-scale trials are important to design the best dosage and strategies for the application of basic substances against pathogens and pests in different growing environments and contexts.

Comparison of the [18F]-FDG and [18F]-FLT PET Tracers in the Evaluation of the Preclinical Proton Therapy Response in Hepatocellular Carcinoma.

PURPOSE: The main objective of the present study was to compare the 2-deoxy-2-[18F]fluoro-D-glucose ([18F]-FDG) and 3'-[18F]fluoro-3'-deoxythymidine ([18F]-FLT) PET imaging biomarkers for the longitudinal follow-up of small animal proton therapy studies in the context of hepatocellular carcinoma (HCC). PROCEDURES: SK-HEP-1 cells were injected into NMRI nude mice to mimic human HCC. The behavior of [18F]-FDG and [18F]-FLT tumor uptake was evaluated after proton therapy procedures. The proton single-fraction doses were 5, 10, and 20 Gy, with a dose rate of 10 Gy/min. The experimental protocol consisted of 8 groups of 10 mice, each group experiencing a particular dose/radiotracer condition. A reference PET exam was performed on each mouse the day before the irradiation procedure, followed by PET exams every 3 days up to 16 days after irradiation. RESULTS: [18F]-FDG uptake showed a linear dose-dependent increase in the first days after treatment (37%, p < 0.05), while [18F]-FLT uptake decreased in a dose-dependent manner (e.g., 21% for 5 Gy compared to 10 Gy, p = 1.1e-2). At the later time point, [18F]-FDG normalized activity showed an 85% decrease (p < 0.01) for both 10 and 20 Gy doses and no variation for 5 Gy. Conversely, a significant 61% (p = 0.002) increase was observed for [18F]-FLT normalized activity at 5 Gy and no variation for higher doses. CONCLUSION: We showed that the use of the [18F]-FDG and [18F]-FLT radiolabeled molecules can provide useful and complementary information for longitudinal follow-up of small animal proton therapy studies in the context of HCC. [18F]-FDG PET imaging enables a treatment monitoring several days/weeks postirradiation. On the other hand, [18F]-FLT could represent a good candidate to monitor the treatment few days postirradiation, in the context of hypo-fractioned and close irradiation planning. This opens new perspectives in terms of treatment efficacy verification depending on the irradiation scheme.

Biorational substitution of piperonyl butoxide in organic production: effectiveness of vegetable oils as synergists for pyrethrums.

Piperonyl butoxide is a semi-synthetic synergist for natural pyrethrum and synthetic pyrethroid insecticides in phytochemicals and biocides. As such it is used in large quantities for crop treatments, stored grain protection, disinfestation of grain storage facilities and indoor uses. Piperonyl butoxide is consequently a regular contaminant in stored grains, and subsequently in corresponding cereal food products and meat via feed uses. Therefore it is regularly monitored and its MRL is ongoing a reassessment. It is also considered as a possible human carcinogen and a suspected endocrine disruptor. For all these reasons and considerations most of the countries have already banned its use in Organic Farming as France in 2017. Thus, ecological substitution of with biorational and sustainable solutions is required. Vegetable oils have been described as exhibiting similar potency and synergistic effects. We have reviewed the literature and have proceeded to ecotoxicological efficacy tests in order to determine the best and most durable substitution candidates. Sesame and rape seed oil were determined to be the most efficient.

O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) uptake in insulinoma: first results from a xenograft mouse model and from human.

INTRODUCTION: Herein we have evaluated the uptake of O-(2-18F-fluoroethyl)-l-tyrosine (18F-FET) in insulinoma in comparison with those of 6-18F-fluoro-3,4-dihydroxy-l-phenylalanine (18F-FDOPA) providing first data from both murine xenograft model and one patient with proved endogenous hyperinsulinemic hypoglycemia. METHODS: Dynamic 18F-FET and carbidopa-assisted 18F-FDOPA PET were performed on tumor-bearing nude mice after subcutaneous injection of RIN-m5F murine beta cells and on a 30-year-old man with type-1 multiple endocrine neoplasia and hyperinsulinemic hypoglycemia defined by a positive fasting test. RESULTS: Seven and three nude mice bearing a RIN-m5F insulinoma xenograft were respectively studied by 18F-FET and 18F-FDOPA µPET. Insulinoma xenograft was detected in all the imaged animals. Xenograft was characterized by an early but moderate increase of 18F-FET uptake followed by a slight decline of uptake intensity during the 20 min dynamic acquisition. Tumoral radiotracer peak intensity and the highest tumor-to-background contrast were reached about 5 minutes after 18F-FET iv. injection (mean SUV: 1.21 ± 0.10). The biodistribution of 18F-FET and 18F-FDOPA and their dynamic tumoral uptake profile and intensity were similar. In the examined patient, 18F-FDOPA and 18F-FET PET/CT showed one concordant focal area of well-defined increased uptake in the pancreatic tail corresponding to 11 mm histologically proved insulinoma. The SUVmax tumor to liver ratio was 1.5, 1.1 for 18F-FDOPA, 1.1, 1 for 18F-FET at early (0-5 min post injection) and delayed (5-20 min post injection) PET/CT acquisition, respectively. Despite the relatively low tumoral uptake intensity, insulinoma was clearly identified due to the low background in the pancreas. At the contrary, no 18F-FDOPA or 18F-FET tumoral uptake was revealed on whole-body PET/CT images performed about 30 min after radiotracer administration. Note of worth, the dynamic uptake pattern of 18F-FET and 18F-FDOPA were similar between human insulinoma and mice xenograft tumor. CONCLUSION: 18F-FET PET compared equally to 18F-FDOPA PET in a preclinical RIN-m5F murine model of insulinoma and in one patient with insulinoma-related hypoglycemia. However, in both cases, the tumoral uptake intensity was moderate and the tumor was only visible until 20 min after radiotracer injection. Hence, caution should be taken before asserting the translational relevance of our results in the clinical practices. However, the structural analogies between 18F-FET and 18F-FDOPA as well as the limited pancreatic uptake of 18F-FET in human, encourage evaluating 18F-FET as diagnostic radiotracer for insulinoma detection in further prospective studies involving large cohorts of patients.

Effect of Carbidopa on 18F-FDOPA Uptake in Insulinoma: From Cell Culture to Small-Animal PET Imaging.

Patient premedication with carbidopa seems to improve the accuracy of 6-18F-fluoro-3,4-dihydroxy-l-phenylalanine (18F-FDOPA) PET for insulinoma diagnosis. However, the risk of PET false-negative results in the presence of carbidopa is a concern. Consequently, we aimed to evaluate the effect of carbidopa on 18F-FDOPA uptake in insulinoma ß-cells and an insulinoma xenograft model in mice. METHODS: 18F-FDOPA in vitro accumulation was assessed in the murine ß-cell line RIN-m5F. In vivo small-animal PET experiments were performed on tumor-bearing nude mice after subcutaneous injection of RIN-m5F cells. Experiments were conducted with and without carbidopa pretreatment. RESULTS: Incubation of RIN-m5F cells with 80 µM carbidopa did not significantly affect the cellular accumulation of 18F-FDOPA. Tumor xenografts were clearly detectable by small-animal PET in all cases. Insulinoma xenografts in carbidopa-treated mice showed significantly higher 18F-FDOPA uptake than those in nontreated mice. Regardless of carbidopa premedication, the xenografts were characterized by an early increase in 18F-FDOPA uptake and then a progressive reduction over time. CONCLUSION: Carbidopa did not influence in vitro 18F-FDOPA accumulation in RIN-m5F cells but improved insulinoma imaging in vivo. Our findings increase current knowledge about the 18F-FDOPA uptake profile of RIN-m5F cells and a related xenograft model. To our knowledge, the present work represents the first preclinical research specifically focused on insulinomas, with potential translational implications.

Phase III randomized trial of induction chemotherapy in patients with N2 or N3 locally advanced head and neck cancer.

PURPOSE: Induction chemotherapy (IC) before radiotherapy lowers distant failure (DF) rates in locally advanced squamous cell carcinoma of the head and neck (SCCHN). The goal of this phase III trial was to determine whether IC before chemoradiotherapy (CRT) further improves survival compared with CRT alone in patients with N2 or N3 disease. PATIENTS AND METHODS: Treatment-naive patients with nonmetastatic N2 or N3 SCCHN were randomly assigned to CRT alone (CRT arm; docetaxel, fluorouracil, and hydroxyurea plus radiotherapy 0.15 Gy twice per day every other week) versus two 21-day cycles of IC (docetaxel 75 mg/m(2) on day 1, cisplatin 75 mg/m(2) on day 1, and fluorouracil 750 mg/m(2) on days 1 to 5) followed by the same CRT regimen (IC + CRT arm). The primary end point was overall survival (OS). Secondary end points included DF-free survival, failure pattern, and recurrence-free survival (RFS). RESULTS: A total of 285 patients were randomly assigned. The most common grade 3 to 4 toxicities during IC were febrile neutropenia (11%) and mucositis (9%); during CRT (both arms combined), they were mucositis (49%), dermatitis (21%), and leukopenia (18%). Serious adverse events were more common in the IC arm (47% v 28%; P = .002). With a minimum follow-up of 30 months, there were no statistically significant differences in OS (hazard ratio, 0.91; 95% CI, 0.59 to 1.41), RFS, or DF-free survival. CONCLUSION: IC did not translate into improved OS compared with CRT alone. However, the study was underpowered because it did not meet the planned accrual target, and OS was higher than predicted in both arms. IC cannot be recommended routinely in patients with N2 or N3 locally advanced SCCHN.

Synthesis of new 2-C-(2,3:5,6-di-O-isopropylidene)-beta-D-mannofuranosyldithioacetate derivatives.

Various new C-glycosides have been synthesized through the thioacylation reaction of different amines by a 2-C-mannofuranosyldithioacetate. Amino acids, di- and polyamines (putresceine, spermine, spermidine) and one amino alcohol were in particular used to generate glycothiopeptidic or precursors of "bola" structures.