Endovascular therapy outcome in isolated posterior cerebral artery occlusion strokes: A multicenter analysis of the Swiss Stroke Registry

PURPOSE

There is little data on the safety and efficacy of endovascular treatment (EVT) in comparison with intravenous thrombolysis (IVT) in acute ischemic stroke due to isolated posterior cerebral artery occlusion (IPCAO). We aimed to investigate the functional and safety outcomes of stroke patients with acute IPCAO treated with EVT (with or without prior bridging IVT) compared to IVT alone.

METHODS

We did a multicenter retrospective analysis of data from the Swiss Stroke Registry. The primary endpoint was overall functional outcome at 3 months in patients undergoing EVT alone or as part of bridging, compared with IVT alone (shift analysis). Safety endpoints were mortality and symptomatic intracranial hemorrhage. EVT and IVT patients were matched 1:1 using propensity scores. Differences in outcomes were examined using ordinal and logistic regression models.

FINDINGS

Out of 17,968 patients, 268 met the inclusion criteria and 136 were matched by propensity scores. The overall functional outcome at 3 months was comparable between the two groups (EVT vs IVT as reference category: OR = 1.42 for higher mRS, 95% CI = 0.78-2.57, p = 0.254). The proportion of patients independent at 3 months was 63.2% in EVT and 72.1% in IVT (OR = 0.67, 95% CI = 0.32-1.37, p = 0.272). Symptomatic intracranial hemorrhages were overall rare and present only in the IVT group (IVT = 5.9% vs EVT = 0%). Mortality at 3 months was also similar between the two groups (IVT = 0% vs EVT = 1.5%).

CONCLUSION

In this multicenter nested analysis, EVT and IVT in patients with acute ischemic stroke due to IPCAO were associated with similar overall good functional outcome and safety. Randomized studies are warranted.

Characterization of chitinases from the GH18 gene family in the myxomycete Physarum polycephalum

BACKGROUND

Physarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze chitin, an important structural component of the cell walls in fungi and in the exoskeleton of insects and crustaceans.

METHODS

Low stringency sequence signature search in transcriptomes was used to identify GH18 sequences related to chitinases. Identified sequences were expressed in E. coli and corresponding structures modelled. Synthetic substrates and in some cases colloidal chitin were used to characterize activities.

RESULTS

Catalytically functional hits were sorted and their predicted structures compared. All share the TIM barrel structure of the GH18 chitinase catalytic domain, optionally fused to binding motifs, such as CBM50, CBM18, and CBM14, involved in sugar recognition. Assessment of the enzymatic activities following deletion of the C-terminal CBM14 domain of the most active clone evidenced a significant contribution of this extension to the chitinase activity. A classification based on module organization, functional and structural criteria of characterized enzymes was proposed.

CONCLUSIONS

Physarum polycephalum sequences encompassing a chitinase like GH18 signature share a modular structure involving a structurally conserved catalytic TIM barrels decorated or not by a chitin insertion domain and optionally surrounded by additional sugar binding domains. One of them plays a clear role in enhancing activities toward natural chitin.

GENERAL SIGNIFICANCE

Myxomycete enzymes are currently poorly characterized and constitute a potential source for new catalysts. Among them glycosyl hydrolases have a strong potential for valorization of industrial waste as well as in therapeutic field.

Évaluation de l’impact de la mise en place d’une consultation d’urgence oncologique thoracique sur les délais de prise en charge au cours de la pandémie de COVID-19

Introduction

L’allongement du délai de prise en charge initial des cancers broncho-pulmonaires (CBP) aboutit à une progression de la maladie. Une consultation d’urgence oncologique dédiée à la prise en charge de patients ayant une suspicion de CBP a été mise en place au CHRU de Nancy le 1^er novembre 2019. La pandémie de COVID-19 a entrainé une sanctuarisation du système de soins, complexifiant la prise en charge des CBP. Peu de données sont disponibles concernant le rôle de programme d’accès rapide au cours de cette pandémie. L’objectif principal est d’évaluer les délais de prise en charge (diagnostique et thérapeutique) après la mise en place d’une consultation d’urgence oncologique thoracique (UOT) et de l’impact de la pandémie de COVID-19 sur ces délais.

Méthodes

Étude rétrospective au CHRU de Nancy. La population est constituée des patients adressés en UOT entre novembre 2019 et février 2021. Les délais analysés sont le délai diagnostique et le délai thérapeutique. Les patients d’UOT sont classés en 2 groupes. Population « UOT pré-COVID-19 » dont le diagnostic est obtenu avant le 1^er mars 2020, population UOT « COVID-19 » dont le diagnostic est obtenu après le 1^er mars. Les délais des populations UOT sont comparés aux délais de la population témoin avant UOT, pris en charge au CHRU de Nancy de novembre 2014 à octobre 2015.

Résultats

Cent six patients ayant bénéficié d’une UOT ont été inclus: 15 patients dans UOT pré-COVID-19 et 91 patients dans UOT COVID-19. Deux cent dix sept patients constituaient la population témoin. Le délai diagnostique moyen était significativement plus court dans le groupe UOT pré-COVID-19, 48,8 jours contre 89,2 jours dans la population témoin, p < 0,01. Les délais moyens diagnostique et thérapeutique n’étaient pas allongés dans le groupe UOT COVID-19 en comparaison à la population témoin, 85,7 contre 89,2 jours et 92 contre 95,3 jours respectivement. Chez les patients ayant bénéficié d’une UOT après le 1^er mars 2020, on observait une tendance à la diminution du nombre de patients adressés à un stade localisé (stade I : 20 % contre 33 % dans la population témoin p = 0,07) et une diminution de la prise en charge chirurgicale. Il existait une diminution du nombre de consultation pendant les deux confinements.

Conclusion

La consultation UOT a significativement diminué le délai diagnostique avant la pandémie de COVID-19. Lors de la pandémie, le nombre de consultations a diminué et les délais ont augmenté avec des patients se présentant à un stade plus avancé de la maladie.

Determination of Zearalenone in Cereal Grains, Animal Feed, and Feed Ingredients Using Immunoaffinity Column Chromatography and Liquid Chromatography: Interlaboratory Study

A method using immunoaffinity column chromatography (IAC) and liquid chromatography (LC) for determination of zearalenone in cereal grains, animal feed, and feed ingredients was collaboratively studied. The test portion is extracted by shaking with acetonitrilewater (90 + 10, v/v) and sodium chloride. The extract is diluted and applied to an immunoaffinity column, the column is washed with water or phosphatebuffered saline or methanolwater (30 + 70, v/v), and zearalenone is eluted with methanol. The eluate is evaporated, the residue is dissolved in mobile phase and analyzed by reversed-phase LC with fluorescence detection. The presence of zearalenone can be confirmed using an alternate excitation wavelength or diode array detection. Twenty samples were sent to 13 collaborators (8 in Europe, 2 in the United States, one in Japan, one in Uruguay, and one in Canada). Eighteen samples of naturally contaminated corn, barley, wheat, dried distillers grains, swine feed, and dairy feed were analyzed as blind duplicates, along with blank corn and wheat samples. The analyses were done in 2 sample sets with inclusion of a spiked wheat control sample (0.1 mg/kg) in each set. Spiked samples recoveries were 89116, and for the 18 naturally contaminated samples, RSDr values (within-laboratory repeatability) ranged from 6.67 to 12.1, RSDR values (among-laboratory reproducibility) ranged from 12.5 to 19.7, and HorRat values ranged from 0.61 to 0.90.

Prevention by a Glucocorticoid of the Thrombotic and Hemorrhagic Tendencies Consecutive to Shock and Surgical Intervention in Rat

Rats pretreated with acenocoumarin present a high incidence of hemorrhages from one to three days after an endotoxemic shock or a surgical intervention. The onset of hemorrhages is concomitant with a marked decrease in the platelet count and a considerable increase in the prothrombin time and the plasma clotting time. These hemorrhages as well as the changes in the parameters examined could be completely prevented by administration of triamcinolone at high doses (4 mg/kg), 2 hrs before and 2 hrs after the shock or the intervention.

Three days after the induction of a traumatic shock in hyperlipemic rats the count and adhesiveness of blood platelets was markedly increased. At this time, the intravenous injection of an endotoxin (S. typhosa lipopolysaccharide) induced a much higher incidence of large phlebothromboses in these traumatized rats than in the control animals. Here again, administration of high doses of triamcinolone could completely block the consequences of the traumatic shock, namely the changes in the platelet count and adhesiveness and the increased thrombotic tendency.

Platelet Functions in Relation to Dietary Fats in Farmers from two Regions of France

To determine whether the long-term feeding of dietary fats affect platelet functions in man, platelet aggregation (to thrombin ADP, collagen, epinephrine) and clotting activity of platelet-rich plasma (PRP), platelet-poor plasma and of washed platelets, were studied in a mobile-laboratory in 44 healthy male farmers (40-45 years) from two French regions Var and Moselle, in relation to lipemia, glycemia, dietary nutriments, and platelet phospholipid composition. In the Moselle subjects, the platelet clotting activity of PRP and of washed platelets, the platelet aggregation to thrombin and ADP, were highly significantly (p <0.001) increased as compared to those of Var, but not the plasma cholesterol, which was identical in the two regions.

In Moselle, the intake of total calories, total lipids and saturated fats was higher than in the Var.

However, it was only with the saturated fat intake (mostly stearic acid) that the platelet clotting activity (p <0.01) and the platelet aggregation (p <0.001) were highly significantly correlated. The platelet clotting activity was also significantly (p <0.001) correlated with the fatty acid composition of the platelet phospholipid fractions phosphatidyl serine + phosphatidyl inositol.

Platelet Factor 3 Activity in Washed Platelets

Platelets collected with an EDTA solution and simply washed in an incomplete Tyrode’s presented clotting times in the recalcification (man and rat) and the Stypven (rat) tests that were practically identical to those of the PRP when slow speed centrifugation was used (800 G in man, 1000 G in rat). This was demonstrated, in 6 pools of 5 rats each and in 6 men, by comparing the clotting activity of the citrated platelet-rich plasma to that of the platelets washed and resuspended in the citrated platelet-poor plasma, for platelet counts ranging from 1 × 105 to 10 × 105/mm3. In contrast, centrifugation of platelets at 3000 G markedly affected these clotting activities, as was shown in an additional study comprising 6 pools of 3 rats.

Finally, the clotting activity of platelets totally disrupted by sonication appears to be identical quantitatively in both man and rats to that of the total phospholipids extracted from these platelets and separated from the other lipids by thin-layer chromatography and resuspended in plasma by sonication.

Role of Platelet Factor 3 in the Hypercoagulability Induced by Pregnancy and Oral Contraceptives

As evaluated in a recording “coagulometer” the Stypven time of 16 to 19 days pregnant Holtzman rats was shorter than that of the controls solely in platelet-rich plasma but not in platelet-poor plasma collected in siliconized material when most of the platelets were removed by slow speed centrifugation (1000 G × 20 minutes). If the same blood was centrifuged at a higher speed (2000 G) the Stypven time was considerably shorter in the pregnant rats even if no platelets were left indicating that platelet factor 3 had been released in plasma during centrifugation.

Identical results were obtained in 10 women taking oral contraceptives as compared to 10 controls. Depending on whether blood was collected in siliconized glassware or not, and final determination performed in plastic or glass, the cephalin clotting time of oral contraceptives treated women was found to be longer, equal or shorter than this of the controls. When it was shorter, a comparable reduction in the Stypven time indicated that the shortening was probably due to “release” of platelet factor 3 in the platelet-poor plasma, in the course of its preparation.

Influence of Pregnancy and Oral Contraceptives on Platelets in Relation to Coagulation ancl Aggregation

Holtzman rats, 16 to 19 days pregnant, exhibited in vitro hypercoagulability with a 27 % reduction in the plasma clotting time (PCT) (siliconized and plastic) as compared to non-pregnant controls. This hypercoagulability was entirely due to an increased activity of platelet factor 3, since a comparable reduction in the clotting time was obtained when the washed platelets from these animals were resuspended in a standard platelet-poor plasma. In contrast to this, when the platelets in the original plasma were replaced by a phospholipid suspension, the clotting time in plastic but not in glass, was prolonged in pregnant rats, suggesting a decreased activity of the contact system. In addition, the pregnant rats exhibited a marked increased susceptibility of platelets to thrombin and to ADP-induced aggregation.

In 6 pregnant women and in 9 women taking contraceptives, a highly significant in vitro hypercoagulability was also present, since the PCT was decreased 26% and 22%, respectively, as compared to the 14 controls. This hypercoagulability appeared to be entirely due to the increased activity of platelet factor 3 as in rat. However, the clear-cut increased susceptibility of platelets to thrombin and ADP-induced aggregation noted in the pregnant rats was not obtained in either the pregnant women or in the women taking contraceptives.

Thrombosis Prevention by Coagulation and Platelet Aggregation Inhibitors, in Hyperlipemic Rats

Phenylbutazone, oxyphenbutazone, and sulfinpyrazone were equally effective at the dosage of 100 mg/kg (per os) in inhibiting thrombin- and ADP-induced platelet aggregation in hyperlipemic rats, and in preventing the development of thrombosis initiated by the intravenous injection of an endotoxin. Despite a slight anticoagulant effect of these substances, their antithrombotic activity appears to be due mostly to inhibition of platelet aggregation.

Thrombosis in hyperlipemic rats could also be prevented by a dicoumarol derivative, acenocoumarin, which only inhibits coagulation. Therefore, both platelet aggregation and fibrin formation appear to be essential for the occurrence of large thrombi under these conditions. Nevertheless, although acenocoumarin has no direct effect on platelet aggregation, it could indirectly affect this phenomenon by blocking the formation of thrombin, which is suspected of being the agent responsible for initiating thrombosis in hyperlipemic rats.

Low doses of phenylbutazone and acenocoumarin, in condition, which when given alone were ineffective in inhibiting thrombosis, could decrease the severity of thrombosis by 33%. The substance GP45840, when added in vitro to platelet-rich plasma as well as given per os to hyperlipemic rats, was no more effective than sulfinpyrazone in inhibiting platelet aggregation. Nevertheless, this substance was significantly more efficient in reducing thrombosis than was sulfinpyrazone, apparently through some additional anticoagulant activity. The results of these experiments suggest that it could be beneficial to affect both coagulation and platelet aggregation in order to satisfactorily prevent thrombosis.

Bioelectronic organ-based sensor for microfluidic real-time analysis of the demand in insulin

On-line and real-time analysis of micro-organ activity permits to use the endogenous analytical power of cellular signal transduction algorithms as biosensors. We have developed here such a sensor using only a few pancreatic endocrine islets and the avoidance of transgenes or chemical probes reduces bias and procures general usage. Nutrient and hormone-induced changes in islet ion fluxes through channels provide the first integrative read-out of micro-organ activity. Using extracellular electrodes we captured this read-out non-invasively as slow potentials which reflect glucose concentration-dependent (3-15 mM) micro-organ activation and coupling. Custom-made PDMS-based microfluidics with platinum black micro-electrode arrays required only some tens of islets and functioned at flow rates of 1-10 µl/min which are compatible with microdialysis. We developed hardware solutions for on-line real-time analysis on a reconfigurable Field-Programmable Gate Array (FPGA) that offered resource-efficient architecture and storage of intermediary processing stages. Moreover, real-time adaptive and reconfigurable algorithms accounted for signal disparities and noise distribution. Based on islet slow potentials, this integrated set-up allowed within less than 40 μs the discrimination and precise automatic ranking of small increases (2 mM steps) of glucose concentrations in real time and within the physiological glucose range. This approach shall permit further development in continuous monitoring of the demand for insulin in type 1 diabetes as well as monitoring of organs-on-chip or maturation of stem-cell derived islets.

Principi e indicazioni dell’assistenza circolatoria e respiratoria extracorporea in chirurgia toracica

In origine, l’extracorporeal membrane oxygenation (ECMO) era una tecnica di assistenza respiratoria che utilizzava uno scambiatore gassoso a membrana. Per estensione, l’ECMO è diventata una tecnica respiratoria e cardiopolmonare utilizzata in caso di deficit respiratorio e/o cardiaco nell’attesa della restaurazione della funzione deficitaria o di un eventuale trapianto. Il supporto emodinamico può essere parziale o totale. Gli accessi vascolari possono essere periferici o centrali. Questo tipo di assistenza utilizza il concetto di circolazione extracorporea (CEC) sanguigna che in epoca moderna si è estesa con l’utilizzo di polmoni artificiali a membrana. Il circuito di base è semplice e comprende una pompa, un ossigenatore (che permette al sangue di caricarsi di O₂ e di eliminare CO₂) e delle vie d’accesso (una di drenaggio e una di reinfusione). La sua attuazione è facile, veloce e può essere avviata al letto del malato. Il miglioramento delle attrezzature, una migliore conoscenza delle tecniche e delle indicazioni, e le politiche di salute pubblica hanno reso popolare questa tecnica. Alcuni centri di chirurgia toracica la utilizzano di routine come assistenza alla realizzazione di un intervento terapeutico (soprattutto trapianto) assieme a team di rianimazione per il trattamento della sindrome da distress respiratorio acuto. Nel quadro della malattia polmonare dell’adulto, l’idea principale è quella di sviluppare il concetto di strategia minimalista con l’uso di una CEC adiuvante parziale – più che sostitutiva totale – che permetterebbe il recupero metabolico ad integrum del paziente. Nei prossimi anni, i progressi della tecnologia e dell’ingegneria così come le conoscenze approfondite permetteranno il miglioramento della prognosi dei pazienti colpiti da deficit respiratorio sotto assistenza meccanica.

Human hepatocellular carcinomas with a periportal phenotype have the lowest potential for early recurrence after curative resection

Hepatocellular carcinomas (HCCs) exhibit a diversity of molecular phenotypes, raising major challenges in clinical management. HCCs detected by surveillance programs at an early stage are candidates for potentially curative therapies (local ablation, resection, or transplantation). In the long term, transplantation provides the lowest recurrence rates. Treatment allocation is based on tumor number, size, vascular invasion, performance status, functional liver reserve, and the prediction of early (<2 years) recurrence, which reflects the intrinsic aggressiveness of the tumor. Well-differentiated, potentially low-aggressiveness tumors form the heterogeneous molecular class of nonproliferative HCCs, characterized by an approximate 50% β-catenin mutation rate. To define the clinical, pathological, and molecular features and the outcome of nonproliferative HCCs, we constructed a 1,133-HCC transcriptomic metadata set and validated findings in a publically available 210-HCC RNA sequencing set. We show that nonproliferative HCCs preserve the zonation program that distributes metabolic functions along the portocentral axis in normal liver. More precisely, we identified two well-differentiated, nonproliferation subclasses, namely periportal-type (wild-type β-catenin) and perivenous-type (mutant β-catenin), which expressed negatively correlated gene networks. The new periportal-type subclass represented 29% of all HCCs; expressed a hepatocyte nuclear factor 4A-driven gene network, which was down-regulated in mouse hepatocyte nuclear factor 4A knockout mice; were early-stage tumors by Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program, and tumor-node-metastasis staging systems; had no macrovascular invasion; and showed the lowest metastasis-specific gene expression levels and TP53 mutation rates. Also, we identified an eight-gene periportal-type HCC signature, which was independently associated with the highest 2-year recurrence-free survival by multivariate analyses in two independent cohorts of 247 and 210 patients.

CONCLUSION

Well-differentiated HCCs display mutually exclusive periportal or perivenous zonation programs. Among all HCCs, periportal-type tumors have the lowest intrinsic potential for early recurrence after curative resection. (Hepatology 2017;66:1502-1518).

Human hepatocellular carcinomas with a periportal phenotype have the lowest potential for early recurrence after curative resection

Hepatocellular carcinomas (HCCs) exhibit a diversity of molecular phenotypes, raising major challenges in clinical management. HCCs detected by surveillance programs at an early stage are candidates for potentially curative therapies (local ablation, resection, or transplantation). In the long term, transplantation provides the lowest recurrence rates. Treatment allocation is based on tumor number, size, vascular invasion, performance status, functional liver reserve, and the prediction of early (<2 years) recurrence, which reflects the intrinsic aggressiveness of the tumor. Well-differentiated, potentially low-aggressiveness tumors form the heterogeneous molecular class of nonproliferative HCCs, characterized by an approximate 50% β-catenin mutation rate. To define the clinical, pathological, and molecular features and the outcome of nonproliferative HCCs, we constructed a 1,133-HCC transcriptomic metadata set and validated findings in a publically available 210-HCC RNA sequencing set. We show that nonproliferative HCCs preserve the zonation program that distributes metabolic functions along the portocentral axis in normal liver. More precisely, we identified two well-differentiated, nonproliferation subclasses, namely periportal-type (wild-type β-catenin) and perivenous-type (mutant β-catenin), which expressed negatively correlated gene networks. The new periportal-type subclass represented 29% of all HCCs; expressed a hepatocyte nuclear factor 4A-driven gene network, which was down-regulated in mouse hepatocyte nuclear factor 4A knockout mice; were early-stage tumors by Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program, and tumor-node-metastasis staging systems; had no macrovascular invasion; and showed the lowest metastasis-specific gene expression levels and TP53 mutation rates. Also, we identified an eight-gene periportal-type HCC signature, which was independently associated with the highest 2-year recurrence-free survival by multivariate analyses in two independent cohorts of 247 and 210 patients.

CONCLUSION

Well-differentiated HCCs display mutually exclusive periportal or perivenous zonation programs. Among all HCCs, periportal-type tumors have the lowest intrinsic potential for early recurrence after curative resection. (Hepatology 2017;66:1502-1518).

Abstract P2-05-11: miR363-3p mediates maintenance and resistance of breast cancer stem cells (BCSC)

Background

BCSC are considered to be involved in the recurrence of breast cancer and its resistance to the systemic therapies. Their detection and targeting remain challenging.

Patients and methods:

The study was conducted in vitro, in xenografted immunecompromised mice and samples of 38 patients with early stage BC having biopsies and blood samples before and after anthraycycline + taxane-based neoadjuvant chemotherapy (NAC). All patients gave written informed consent before inclusion. 1) MCF7 cells grown as mammospheres (MS) for BCSC enrichment were treated with 5FU or paclitaxel (Pac) to select chemo-resistant BCSC. miRNA microarray was performed to identify specific miRNAs for chemo-resistant BCSC. The results were compared to miRNAs found in immortalized non-tumorigenic MCF10A cells to exclude miRNAs related to normal stem cells. 2) The correlation between the most highly expressed miRNA and the BCSC was confirmed by RT-qPCR in ALDH+ and ALDH- cells sorted from MCF7 and MDA-MB-231 cells by flow cytometry. 3) The impact of the miRNA on MS and colony development was assessed by up- and down-regulating its expression. MCF7 cells transfected with ectopic expression of miRNA, anti-miRNA or miRNA control were grown in MS before being injected in mice using a mouse INtraDuctal xenograft Model (MIND). In vivo tumor growth was assessed by luciferase imaging, then measured and quantified with human GAPDH ex vivo at 6 weeks. 4) The miRNA was quantified by RT-qPCR in tumor samples and sera of the patients before and after treatment, and its levels were correlated with pathological complete response and patients' outcomes.

Results:

379 miRNAs out of 2006 were altered in chemo-resistant versus untreated MCF7 MS. Thirteen were specific for 5FU and 5 for Pac. Three were common for both drugs. Of these, miR-363-3p was overexpressed specifically in BCSC-enriched chemo-resistant MCF7 cells and all the other tested BC cell lines, but not in non-tumorigenic MCF10A cells. Compared to adherent MCF7 cells, miR-363-3p was 12-, 60-, and 10-folds more expressed in BCSC-enriched MS treated with 5FU, Pac, or without treatment, respectively. miR-363-3p was 20- and 100-folds higher in ALDH+ compared to ALDH- in MCF7 and MDA-MB-231 cells. Anti-miR-363-3p reduced MS size and decreased their number 50%. A significant decrease of the number of colonies was also observed in soft agar. Consistently, miR-363-3p downregulation decreased tumor growth and metastasis by MCF7 cells transplanted in mice. In patients' sera with lower baseline level (n=15), miR-363-3p appeared decreased upon NAC. Patients with high miR-363-3p serum levels (n=22) had more risk to maintain higher level after chemotherapy. Triple-negative and HER2+ BC were more frequent in this second group. No significant difference was observed in term of pCR between the 2 groups. However 3 patients relapsed with distant metastases and all were in the second group with high baseline level and no decrease after NAC.

Conclusions:

miR363-3p appeared to be a mediator of chemo-resistant BCSC. Its measurement in the serum of BC patients may predict resistance to neo-/adjuvant chemotherapy and higher risk of distant recurrence. Further investigations are warranted to confirm its role as biomarker and potential therapeutic target against BCSC.

Citation Format: Renaud S, Fiche M, Stravodimou A, Scabia V, Dormoy VM, Galmiche Rindisbacher M, Brisken C, Mermod N, Zaman K. miR363-3p mediates maintenance and resistance of breast cancer stem cells (BCSC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-11.

"Fibrous nests" in human hepatocellular carcinoma express a Wnt-induced gene signature associated with poor clinical outcome

Hepatocellular carcinoma (HCC) is the 3rd cause of cancer-related death worldwide. Most cases arise in a background of chronic inflammation, extracellular matrix (ECM) remodeling, severe fibrosis and stem/progenitor cell amplification. Although HCCs are soft cellular tumors, they may contain fibrous nests within the tumor mass. Thus, the aim of this study was to explore cancer cell phenotypes in fibrous nests. Combined anatomic pathology, tissue microarray and real-time PCR analyses revealed that HCCs (n=82) containing fibrous nests were poorly differentiated, expressed Wnt pathway components and target genes, as well as markers of stem/progenitor cells, such as CD44, LGR5 and SOX9. Consistently, in severe liver fibroses (n=66) and in HCCs containing fibrous nests, weighted correlation analysis revealed a gene network including the myofibroblast marker ACTA2, the basement membrane components COL4A1 and LAMC1, the Wnt pathway members FZD1; FZD7; WNT2; LEF1; DKK1 and the Secreted Frizzled Related Proteins (SFRPs) 1; 2 and 5. Moreover, unbiased random survival forest analysis of a transcriptomic dataset of 247 HCC patients revealed high DKK1, COL4A1, SFRP1 and LAMC1 to be associated with advanced tumor staging as well as with bad overall and disease-free survival. In vitro, these genes were upregulated in liver cancer stem/progenitor cells upon Wnt-induced mesenchymal commitment and myofibroblast differentiation. In conclusion, fibrous nests express Wnt target genes, as well as markers of cancer stem cells and mesenchymal commitment. Fibrous nests embody the specific microenvironment of the cancer stem cell niche and can be detected by routine anatomic pathology analyses.

Recent advances in cancer treatment by iron chelators

The development of new therapeutic alternatives for cancers is a major public health priority. Among the more promising approaches, the iron depletion strategy based on metal chelation in the tumoral environment has been particularly studied in recent decades. After a short description of the importance of iron for cancer cell proliferation, we will review the different iron chelators developed as potential chemotherapeutics. Finally, the recent efforts to vectorize the chelating agents specifically in the microtumoral environment will be discussed in detail.

High expression of hTERT and stemness genes in BORIS/CTCFL positive cells isolated from embryonic cancer cells

BORIS/CTCFL is a member of cancer testis antigen family normally expressed in germ cells. In tumors, it is aberrantly expressed although its functions are not completely well-defined. To better understand the functions of BORIS in cancer, we selected the embryonic cancer cells as a model. Using a molecular beacon, which specifically targets BORIS mRNA, we demonstrated that BORIS positive cells are a small subpopulation of tumor cells (3–5% of total). The BORIS-positive cells isolated using BORIS-molecular beacon, expressed higher telomerase hTERT, stem cell (NANOG, OCT4, SOX2) and cancer stem cell marker genes (CD44 and ALDH1) compared to the BORIS-negative tumor cells. In order to define the functional role of BORIS, stable BORIS-depleted embryonic cancer cells were generated. BORIS silencing strongly down-regulated the expression of hTERT, stem cell and cancer stem cell marker genes. Moreover, the BORIS knockdown increased cellular senescence in embryonic cancer cells, revealing a putative role of BORIS in the senescence biological program. Our data indicate an association of BORIS expressing cells subpopulation with the expression of stemness genes, highlighting the critical role played by BORIS in embryonic neoplastic disease.

Systematic lymph node dissection in lung metastasectomy of renal cell carcinoma: an 18 years of experience

BACKGROUND

Pulmonary metastasectomy of renal cell carcinomas (RCC) remains controversial. Thoracic lymph node involvement (LNI) is a known prognostic factor. The aim of our analysis is to evaluate whether patients with LNI, and particularly N2 patients, should be excluded from surgical treatment.

METHODS

We retrospectively reviewed data from 122 patients who underwent operations at two French thoracic surgery departments between 1993 and 2011 for RCC lung metastases.

RESULTS

The population consisted of 38 women and 84 men; the average age at time of metastasectomy was 63.3 years (min: 43, max: 82). LNI was identified as a prognostic factor using univariate and multivariate analysis (median survival: 107 months vs. 37 months, P = 0.003; HR = 0.384 (0.179; 0.825), P = 0.01, respectively). Although differences in survival between metastases at the hilar and mediastinal locations were not significant (median survival: 74 months vs. 32 months, respectively, P = 0.75), length of survival time was associated with disease-free interval less than 12 months (median survival: 23 months vs. 94 months, P < 0.0001; HR = 3.081 (1.193; 7.957), P = 0.02).

CONCLUSION

Although LNI has an adverse effect on survival; long-term survival can be achieved in pN+ patients. Consequently, these patients should not be excluded from surgery. Systematic lymphadenectomy should be performed to obtain more accurate staging and to determine appropriate adjuvant treatment.

Invasive house mice facing a changing environment on the Sub-Antarctic Guillou Island (Kerguelen Archipelago)

Adaptation to new environments is a key feature in evolution promoting divergence in morphological structures under selection. The house mouse (Mus musculus domesticus) introduced on the Sub-Antarctic Guillou Island (Kerguelen Archipelago) had and still has to face environmental conditions that likely shaped the pattern and pace of its insular evolution. Since mouse arrival on the island, probably not more than two centuries ago, ecological conditions dramatically differed from those available to their Western European commensal source populations. In addition, over the last two decades, the plant and animal communities of Guillou Island were considerably modified by the eradication of rabbits, the effects of climate change and the spread of invasive species detrimental to native communities. Under such a changing habitat, the mouse response was investigated using a morphometric quantification of mandible and molar tooth, two morphological structures related to food processing. A marked differentiation of the insular mice compared with their relatives from Western Europe was documented for both mandibles and molar shapes. Moreover, these shapes changed through the 16 years of the record, in agreement with expectations of drift for the molar, but more than expected by chance for the mandible. These results suggest that mice responded to the recent changes in food resources, possibly with a part of plastic variation for the mandible prone to bone remodelling. This pattern exemplifies the intricate interplay of evolution, ecology and plasticity that is a probable key of the success of such an invasive rodent facing pronounced shifts in food resources exploitation under a changing environment.

Robotic-assisted thymectomy with Da Vinci II versus sternotomy in the surgical treatment of non-thymomatous myasthenia gravis: early results

BACKGROUND

The role of thymectomy in myasthenia gravis remains controversial. The remission rate 5years after surgery varies from 13 to 51% in the literature. Sternotomy is the standard technique, though unacceptable by patients because of significant esthetic sequelae. Our objective was to demonstrate that the robot-assisted technique using the Da Vinci Surgical Robot II is at least as efficient and leaves fewer scars than the standard surgical technique.

METHODS

We retrospectively reviewed the data of 31 consecutive patients suffering from myasthenia gravis who underwent surgery in our center from January 1998 to March 2010. Ten patients with thymoma were excluded from this study. Two groups were formed: group 1 corresponding to patients treated with sternotomy, group 2 patients with robot-assisted technique. The duration of the hospital stay, the pain on D1, the degree of improvement at 1year according to Myasthenia Gravis Foundation of America (MGFA) classification, the frequency of relapses, and perioperative treatment were studied.

RESULTS

Our sample consisted of 14 women and seven men. The mean age was 31.3years. The mean delay before surgery was 24months. Group 1 included 15 patients and group 2 had six patients. The complete remission rate at 1year was 9.5% (n=2). Surgery decreased the frequency of relapses after surgery (P=0.08) equally in the two groups. The duration of hospital stay and the pain level on D1 in group 2 were significantly lower than those in group 1 (P=0.02 and P<0.001). The degree of postoperative improvement was not significantly different between the two groups (P=0.31).

CONCLUSION

The results at 1year are fully comparable for sternotomy and the robot-assisted technique. The robot provides additional benefits of minimally invasive techniques: minimal esthetic sequelae in often young patients, less parietal morbidity (including pain), shorter hospital stays. Our complete remission rate, lower than those in the literature, must be considered taking into account the early nature of these results. The surgical robot, because of its many advantages, appears to be a promising technique and should facilitate the early management of these patients.

[Management of massive hemoptysis]

Massive hemoptyses are serious clinical conditions that can quickly jeopardize the vital prognosis. The major risk is asphyxiation, due to the bleeding into the tracheobronchial tree. The clinician should provide in parallel support for diagnosis and treatment, locating the bleeding but also finding its cause. Such patients should be cared for by a multidisciplinary team, having quick access to an important technical support. The association fiberoptic bronchoscopy-chest CT scan seems to be the most effective to locate and identify the cause of the bleeding. The development of bronchial artery embolization has revolutionized the management of these patients, replacing surgery in many of its indications. The latter still keeps a place in the management of these patients. Indeed, it is the main etiological treatment, preventing the vast majority of recidivism. It is absolutely indicated in the treatment of bleeding from the pulmonary vessels, and in case of failure of other techniques. It should be performed whenever possible away from the episode of hemoptysis, in order to minimize the operative risk.

[DNA microarray analysis in nerve biopsies of patients with vasculitic neuropathy]

DNA microarray analysis is a powerful tool for simultaneous analysis and comparison of gene products expressed in normal and diseased tissues. We used this technique to identify differentially expressed genes (DEGs) in nerve biopsy samples of vasculitic neuropathy (VAS) patients. We find novel previously uncharacterized genes of relevance to VAS pathogenesis. Genes upregulated in VAS include IGLJ3, IGHG3, IGKC, and IGL, which all function in B-cell selection or antigen recognition of B cells. Other upregulated genes are chemokines, such as CXCL9 and CCR2 and CX3CR1. Allograft inflammatory factor-1 (AIF-1), a modulator of immune response is upregulated in VAS. We demonstrate by immunolocalisation the expression of AIF-1 in vascular smooth muscle cells, suggesting a role for AIF-1 in vascular remodeling in VAS. Microarray-based analysis of human nerve biopsies shows distinct gene expression patterns in VAS. DEGs might provide clues to the pathogenesis of this condition and help define potential targets for therapeutics.

FLEXOR TENDON SHEATH GANGLION: ANALYSIS OF 128 CASES

A 30-year analysis of 128 patients with flexor tendon sheath ganglion was investigated. The majority of patients were females with sex ratio of 2.6 : 1. Most of the patients are in their third to fifth decade of life. Hand dominance, previous trauma as well as other illnesses involving the hand did not show any correlation to the formation of ganglion. The middle finger was most commonly affected and 69% of the ganglion were located on A1 and A2 pulley. Recurrence was high (89%) after multiple percutaneous puncture and treatment was successful with no cases of recurrence after surgical excision.

Protein-binding microarray analysis of tumor suppressor AP2α target gene specificity

Cheap and massively parallel methods to assess the DNA-binding specificity of transcription factors are actively sought, given their prominent regulatory role in cellular processes and diseases. Here we evaluated the use of protein-binding microarrays (PBM) to probe the association of the tumor suppressor AP2α with 6000 human genomic DNA regulatory sequences. We show that the PBM provides accurate relative binding affinities when compared to quantitative surface plasmon resonance assays. A PBM-based study of human healthy and breast tumor tissue extracts allowed the identification of previously unknown AP2α target genes and it revealed genes whose direct or indirect interactions with AP2α are affected in the diseased tissues. AP2α binding and regulation was confirmed experimentally in human carcinoma cells for novel target genes involved in tumor progression and resistance to chemotherapeutics, providing a molecular interpretation of AP2α role in cancer chemoresistance. Overall, we conclude that this approach provides quantitative and accurate assays of the specificity and activity of tumor suppressor and oncogenic proteins in clinical samples, interfacing genomic and proteomic assays.