Disseminated and circulating tumor cells in gastrointestinal oncology.

International audienceCirculating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers

Locoregional treatment of primary tumor in synchronous metastatic head and neck squamous cell carcinomas

International audiencePurpose: Patients with synchronous metastatic head and neck squamous cell carcinomas (mHNSCC) are at risk of locoregional progression associated with significant morbidity and mortality. The aim of this study is to assess whether the addition of aggressive locoregional treatment to systemic therapy could be associated with an improved overall survival (OS) compared to systemic therapy alone in upfront mHNSCC patients.Material and methods: This retrospective study included patients presenting with previously untreated mHNSCC who underwent first-line systemic therapy at a single institution between 1998 and 2018. Locoregional treatment was defined as either exclusive locoregional radiotherapy (RT) or surgery with or without adjuvant RT.Results: One hundred forty-eight patients were included. Eighty patients were treated with systemic therapy alone and 68 patients were treated with a combination of locoregional treatment and systemic therapy. Median overall survival (OS) was 13 months [10.7-15] and median progression free survival (PFS) was 7.7 month [6.5-8.9]. The addition of a locoregional treatment to systemic therapy compared to systemic therapy alone was associated with improved survival (1-year OS, 65.8% vs. 41.1%, p < .001, and 1-year PFS, 42.5% vs. 18.5%, p < .001). Moreover, RT dose equal to 70 Gy was associated with even longer OS compared to a RT dose below 70 Gy and to no locoregional treatment (23.4 vs. 12.7 vs 7.5 months respectively). In a subgroup analysis on 75 patients presenting with a responding or stable metastatic disease after first-line systemic therapy, oropharyngeal primary tumor site and the addition of a locoregional treatment, especially a high radiation dose of 70 Gy, were evidenced as independent prognostic factors for improved OS.Conclusion: The addition of a high-dose RT locoregional treatment to systemic therapy is associated with prolonged OS in patients with synchronous mHNSCC and should be discussed for patients who respond to or have a stable disease after first-line systemic therapy

Probing the light hole / heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot

International audienceA whole series of complementary studies have been performed on the same, single nanowire containing a quantum dot: cathodoluminescence spectroscopy and imaging, micro-photoluminescence spectroscopy under magnetic field and as a function of temperature, and energy-dispersive X-ray spectrometry and imaging. The ZnTe nanowire was deposited on a Si 3 N 4 membrane with Ti/Al patterns. The complete set of data shows that the CdTe quantum dot features the heavy-hole state as a ground state, although the compressive mismatch strain promotes a light-hole ground state as soon as the aspect ratio is larger than unity (elongated dot). A numerical calculation of the whole structure shows that the transition from the heavy-hole to the light-hole configuration is pushed toward values of the aspect ratio much larger than unity by the presence of a (Zn,Mg)Te shell, and that the effect is further enhanced by a small valence band offset between the semiconductors in the dot and around it

Probing the light hole / heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot

International audienceA whole series of complementary studies have been performed on the same, single nanowire containing a quantum dot: cathodoluminescence spectroscopy and imaging, micro-photoluminescence spectroscopy under magnetic field and as a function of temperature, and energy-dispersive X-ray spectrometry and imaging. The ZnTe nanowire was deposited on a Si 3 N 4 membrane with Ti/Al patterns. The complete set of data shows that the CdTe quantum dot features the heavy-hole state as a ground state, although the compressive mismatch strain promotes a light-hole ground state as soon as the aspect ratio is larger than unity (elongated dot). A numerical calculation of the whole structure shows that the transition from the heavy-hole to the light-hole configuration is pushed toward values of the aspect ratio much larger than unity by the presence of a (Zn,Mg)Te shell, and that the effect is further enhanced by a small valence band offset between the semiconductors in the dot and around it

Consistent high concentration of the viral microRNA BART17 in plasma samples from nasopharyngeal carcinoma patients - evidence of non-exosomal transport.

International audienceBACKGROUND: Because latent Epstein Barr (EBV)-infection is a specific characteristic of malignant nasopharyngeal carcinoma (NPC), various molecules of viral origin are obvious candidate biomarkers in this disease. In a previous study, we could show in a few clinical samples that it was possible to detect a category of EBV microRNAs called miR-BARTs in the plasma of at least a fraction of NPC patients. The first aim of the present study was to investigate the status of circulating miR-BART17-5p (one of the miR-BARTs hereafter called miR-BART17) and EBV DNA in a larger series of NPC plasma samples. The second aim was to determine whether or not circulating miR-BART17 was carried by plasma exosomes. PATIENTS AND METHODS: Plasma samples were collected from 26 NPC patients and 10 control donors, including 9 patients with non-NPC Head and Neck squamous cell carcinoma and one healthy EBV carrier. Concentrations of miR-BART17 and two cellular microRNAs (hsa-miR-16 and -146a) were assessed by real-time quantitative PCR with spike-in normalization and absolute quantification. In addition, for 2 patients, exosome distributions of miR-BART17 and miR-16 were investigated following plasma lipoprotein fractionation by isopycnic density gradient ultrcentrifugation. RESULTS: The miR-BART17 was significantly more abundant in plasma samples from NPC patients compared to non-NPC donors. Above a threshold of 506 copies/mL, detection of miR-BART17 was highly specific for NPC patients (ROC curve analysis: AUC=0.87 with true positive rate = 0.77, false positive rate = 0.10). In this relatively small series, the concentration of plasma miR-BART17 and the plasma EBV DNA load were not correlated. When plasma samples were fractionated, miR-BART17 co-purified with a protein-rich fraction but not with exosomes. CONCLUSIONS: Detection of high concentrations of plasma miR-BART17 is consistent in NPC patients. This parameter is, at least in part, independent of the viral DNA load. Circulating miR-BART17 does not co-purify with exosomes

Treatment of Nasopharyngeal Carcinoma Cells with the Histone-Deacetylase Inhibitor Abexinostat: Cooperative Effects with Cis-platin and Radiotherapy on Patient-Derived Xenografts

<div><p>EBV-related nasopharyngeal carcinomas (NPCs) still raise serious therapeutic problems. The therapeutic potential of the histone-deacetylase (HDAC) inhibitor Abexinostat was investigated using 5 preclinical NPC models including 2 patient-derived xenografts (C15 and C17). The cytotoxicity of Abexinostat used either alone or in combination with cis-platin or irradiation was assessed <i>in vitro</i> by MTT and clonogenic assays using 2 EBV-negative (CNE1 and HONE1) and 3 EBV-positive NPC models (C15, C17 and C666-1). Subsequently, the 3 EBV-positive models were used under the form of xenografts to assess the impact of systemic treatments by Abexinostat or combinations of Abexinostat with cis-platin or irradiation. Several cell proteins known to be affected by HDAC inhibitors and the small viral non-coding RNA EBER1 were investigated in the treated tumors. Synergistic cytotoxic effects of Abexinostat combined with cis-platin or irradiation were demonstrated <i>in vitro</i> for each NPC model. When using xenografts, Abexinostat by itself (12.5 mg/kg, BID, 4 days a week for 3 weeks) had significant anti-tumor effects against C17. Cooperative effects with cis-platin (2 mg/kg, IP, at days 3, 10 and 17) and irradiation (1Gy) were observed for the C15 and C17 xenografts. Simultaneously two types of biological alterations were induced in the tumor tissue, especially in the C17 model: a depletion of the DNA-repair protein RAD51 and a stronger <i>in situ</i> detection of the small viral RNA EBER1. Overall, these results support implementation of phase I/II clinical trials of Abexinostat for the treatment of NPC. A depletion of RAD51 is likely to contribute to the cooperation of Abexinostat with DNA damaging agents. Reduction of RAD51 combined to enhanced detection of EBER 1 might be helpful for early assessment of tumor response.</p></div

Protein modifications induced by Abexinostat in EBV-positive NPC cells treated <i>in vitro</i>.

<p>These experiments were done on C666-1 cells routinely propagated <i>in vitro</i> (C666-1) and on cells resulting from collagenase dispersion of C15 and C17 patient-derived xenografts (C15 and C17 cells <i>ex vivo</i>). Treatment with Abexinostat at various concentrations (0, 50, 125, 400 and 1000 nM) was applied continuously for two days (D1 and D2). Cell proteins were then extracted and separated on PAGE gels (20 µg/lane). Parallel Western blots were done for acetylated α-tubulin, α-tubulin, PARP1, RAD51, RAD23B and actin. Protein abundance in each lane was evaluated by densitometry. For loading normalization, all proteins were referred to actin except acetylated α-tubulin which was referred to total α-tubulin. Protein abundance in lanes corresponding to untreated samples was arbitrarily set at 1. Surprisingly PARP cleavage is observed for C17 cells treated with 400 nM but not 1000 nM Abexinostat. Because C17 cells were very sensitive to Abexinostat, we suspect that when treated with a high concentration of the compound they died by a non-apoptotic mechanism possibly related to necrosis.</p

Clonogenic assays on NPC cells treated <i>in vitro</i> with Abexinostat combined with external irradiation.

<p>The experiments corresponding to the most successful combinations of treatment dosages are presented for HONE1, CNE1 and C666-1. Cells were plated as explained in the Materials and Methods section. Treatment by Abexinostat was started 24 hours following cell plating and irradiation was done 24 h after the onset of Abexinostat. About 3 weeks later cell clones were numbered for calculation of the percentages of growth inhibition (which are mentioned under the picture of each well). For C666-1 cells treated with Abexinostat by itself (50 nM), clonal growth was slightly enhanced instead of being inhibited. The EOBA which reflects the level of synergy for the combined treatment is mentioned for each NPC model. The panel of each model is representative of 3 similar experiments.</p

Short term culture assays on NPC cells treated <i>in vitro</i> with Abexinostat plus CDDP.

<p>The best combinations of drug dosages are represented graphically. EBV-negative (HONE1 and CNE1) and EBV–positive NPC cells (C15 cells <i>ex vivo</i>, C17 cells <i>ex vivo</i> and C666-1 cells) were treated for 48 h with combinations involving various concentrations of Abexinostat (25, 50, 75 and 150 nM) and CDDP (0.5, 1 and 2 µM). Cell viability was determined in short term assays based on the reduction of MTT (CNE1, HONE1) or WST (C15 <i>ex vivo</i>, C17 <i>ex vivo</i> and C666-1) using triplicates for each experimental conditions. For each NPC model, the result of the most successful combination of drug dosages is depicted as a color disk whose size is proportional to the EOBA index. This index mentioned as a two-digit number reflects the level of synergy for the combined treatment: values greater than 10 are indicative of a synergy between the 2 compounds (see the Materials and Methods section for additional explanations). The X and Y coordinates of the disk stand for the corresponding concentrations of Abexinostat and CDDP respectively. For CNE1 and C666-1, the effects of the combined treatment were only additive. The highest levels of synergy were recorded for C17-cells <i>ex vivo</i>, HONE1 and C15-cells <i>ex vivo</i>.</p