Tech sharing, not tech hoarding: Covid-19, global solidarity, and the failed responsibility of the pharmaceutical industry

The Covid-19 pandemic has highlighted the importance of health technologies to mitigate against the spread of the disease and improve care, dominantly including life-saving vaccines. But the pandemic has also highlighted that the current biopharmaceutical business model, based on the enclosure of these technologies and on the immense accumulation of capital it enables, leads to vast inequalities in healthcare particularly in low and middle-income countries. We believe that the pharmaceutical industry has a moral duty to enable and enact global solidarity through tech sharing instead of tech hoarding, but judging by current technology transfer practices we question their willingness to assume their role in organizing healthcare markets through solidaristic principles. In the absence of a voluntary adoption of solidaristic principles and practices by biopharmaceutical firms, the institutionalization of global solidarity as a fundamental organizing principle for healthcare markets is necessary to strengthen resilience and know-how globally. With this call, we add to existing conceptualizations of solidarity by (a) introducing a global level of solidarity and (b) thinking through the concept not as an abstract humanistic stance but as a concrete organizing principle for global healthcare markets.

Abstract 1970: Single cell proteomic quantification of T cell states using mass cytometry for applications in monitoring immune responses in cancer immunotherapy clinical trials

Although immunotherapies have been established as a successful treatment option for several types of cancers, additional treatment strategies are necessary to broaden the cohorts of patients who may receive clinical benefit. Common immunological profiling for immunotherapy response depends on assessment of the composition of immune cell types in tissue samples and the periphery. Still, the function and state of each of these cells further contributes to the ultimate clinical benefit of immunotherapeutic response. Additionally, our ability to comprehensively study treatment strategies depends on elucidating the temporal effects different immunotherapy regimens have on the immune system of patients. Single-cell proteomics profiling with CyTOF mass cytometry enables robust protein-level profiling of cell types and is also high-dimensional enough to characterize functional states of immune cells. To construct an immunological framework that may feasibly serve to empower functional assessment of immune cell states for clinical trial monitoring strategies using CyTOF, we are employing single cell trajectory inference methods and non-negative matrix factorization (NMF). We demonstrate this approach using peripheral blood derived CyTOF mass cytometry data to model T cell states at the proteomic level. First, we extract T helper (Th) and T cytotoxic (Tc) cell integrated metrics from CyTOF mass cytometry data obtained from diverse cell marker panel designs, immunological states, and diseases to benchmark that these computational pipelines can accurately reflect Th and Tc activation and exhaustion. Next, we develop a new pipeline that enables the use of continuous functional cell-state metrics from continuous pseudotime and NMF pattern weights as immunological profiling markers from CyTOF that can be applied to cancer immunotherapy clinical trials. For instance, we find CyTOF Tc pseudotime and memory pattern weights are higher in PDAC patients with stable disease treated with ipilimumab and a pancreatic cancer-specific vaccine. Thus, our pipeline has the ability to integrate metrics from mass cytometry data to empower translational analyses for determining patient responses in cancer immunotherapy, such as adaptive immune responses to checkpoint inhibitors and cancer vaccines. Moreover, applying this pipeline to peripheral blood samples obtained before and after treatment also enables us to map further temporal cell state transitions in Tc and Th cells resulting from that treatment. Future work will include leveraging CyTOF T cell integrated metrics in larger scale survival analyses to test the predictive potential in a clinical proof of concept.

Citation Format: Dimitrios N. Sidiropoulos, Zaw Phyo, Nicole Gross, Soren Charmsaz, Stephanie Xavier, James Leatherman, Mark Yarchoan, Elizabeth M. Jaffee, Elana J. Fertig, Won Jin Ho. Single cell proteomic quantification of T cell states using mass cytometry for applications in monitoring immune responses in cancer immunotherapy clinical trials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1970.

Neoadjuvant Cabozantinib and Nivolumab Converts Locally Advanced HCC into Resectable Disease with Enhanced Antitumor Immunity

A potentially curative hepatic resection is the optimal treatment for hepatocellular carcinoma (HCC), but most patients are not candidates for resection and most resected HCCs eventually recur. Until recently, neoadjuvant systemic therapy for HCC has been limited by a lack of effective systemic agents. Here, in a single arm phase 1b study, we evaluated the feasibility of neoadjuvant cabozantinib and nivolumab in patients with HCC including patients outside of traditional resection criteria (NCT03299946). Of 15 patients enrolled, 12 (80%) underwent successful margin negative resection, and 5/12 (42%) patients had major pathologic responses. In-depth biospecimen profiling demonstrated an enrichment in T effector cells, as well as tertiary lymphoid structures, CD138+ plasma cells, and a distinct spatial arrangement of B cells in responders as compared to non-responders, indicating an orchestrated B-cell contribution to antitumor immunity in HCC.

Abstract 1682: Imaging mass cytometry reveals key spatial features among immune cells in hepatocellular carcinomas treated with neoadjuvant cabozantinib and nivolumab

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and carries a poor prognosis. Most HCC is unresectable at presentation, and until recently, the use of perioperative systemic therapy has been hampered by a lack of any effective therapies. We recently conducted a single-arm trial of neoadjuvant cabozantinib followed by nivolumab for borderline resectable or locally advanced HCC (NCT03299946), through which secondary resectability was obtained in a subset of patients. Of 15 patients enrolled, 12/15 patients achieved margin-negative resection, and 5/12 resected patients experienced a major or complete pathologic response. Here we characterize changes in the tumor microenvironment (TME) induced by neoadjuvant therapy. We constructed a tissue microarray containing 37 core liver biopsies (15 from responders, 22 from nonresponders), stained with a 27-marker panel, and used ilastik and CellProfiler to segment the resulting images, producing a single-cell dataset comprising 59,453 cells. We then used FlowSOM to perform unbiased clustering of cells, which we annotated into 17 cell types. Next, we performed spatial analysis using Voronoi diagrams and top neighbors mapping. We generated a minimum spanning tree using shortest Euclidean distances to model the simplest spatial relationships among all cell types and ranked their importance using random forest models. Grossly, responder cores were characterized by the presence of tertiary lymphoid aggregates, as well as a higher percent abundance of several immune cell types, including CD4 T (p < 0.05) and CD8 T cells (p < 0.005). In responders, Voronoi diagrams revealed denser packing of most immune cell types, particularly B cells (p < 0.005), and top neighbors analysis indicated higher numbers of lymphoid-lymphoid, myeloid-myeloid, and lymphoid-myeloid neighbors. This suggests that response is characterized by immune infiltration of the TME. Exploring this further, a minimum spanning tree showed that in nonresponders, CD8 T cells were flanked by CD163+ macrophages, whereas in responders, HCC cells were closely linked to lymphoid cells. Importance plots from random forest models for B, CD4 T, and CD8 T cells revealed that top predictors of responder status were higher minimum distance from CD163+ Arg1+ macrophages and lower minimum distance from CD163+ Ki67+ macrophages, which express higher levels of PD-L1. This suggests that proximity of B and T cells to macrophages that exert immunosuppression via Arg1 is a critical feature of resistance to cabozantinib plus nivolumab, whereas proximity to proliferative macrophages that express higher levels of PD-L1 is a key feature of response. In conclusion, cabozantinib and nivolumab can effectively promote antitumor immunity by altering both the abundance and spatial organization of macrophages, B cells, and T cells in the HCC TME.

Citation Format: Shu Zhang, Qingfeng Zhu, Nicole Gross, Soren Charmsaz, Atul Deshpande, Stephanie Xavier, Aditya Mohan, James Leatherman, Guanglan Mo, Jennifer Durham, Aleksandra Popovic, Brad Wilt, Dongxia Lin, Derek Quong, Robert Anders, Elana Fertig, Elizabeth M. Jaffee, Mark Yarchoan, Won J. Ho. Imaging mass cytometry reveals key spatial features among immune cells in hepatocellular carcinomas treated with neoadjuvant cabozantinib and nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1682.

Multi-omic profiling of lung and liver tumor microenvironments of metastatic pancreatic cancer reveals site-specific immune regulatory pathways

BACKGROUND

The majority of pancreatic ductal adenocarcinomas (PDAC) are diagnosed at the metastatic stage, and standard therapies have limited activity with a dismal 5-year survival rate of only 8%. The liver and lung are the most common sites of PDAC metastasis, and each have been differentially associated with prognoses and responses to systemic therapies. A deeper understanding of the molecular and cellular landscape within the tumor microenvironment (TME) metastasis at these different sites is critical to informing future therapeutic strategies against metastatic PDAC.

RESULTS

By leveraging combined mass cytometry, immunohistochemistry, and RNA sequencing, we identify key regulatory pathways that distinguish the liver and lung TMEs in a preclinical mouse model of metastatic PDAC. We demonstrate that the lung TME generally exhibits higher levels of immune infiltration, immune activation, and pro-immune signaling pathways, whereas multiple immune-suppressive pathways are emphasized in the liver TME. We then perform further validation of these preclinical findings in paired human lung and liver metastatic samples using immunohistochemistry from PDAC rapid autopsy specimens. Finally, in silico validation with transfer learning between our mouse model and TCGA datasets further demonstrates that many of the site-associated features are detectable even in the context of different primary tumors.

CONCLUSIONS

Determining the distinctive immune-suppressive features in multiple liver and lung TME datasets provides further insight into the tissue specificity of molecular and cellular pathways, suggesting a potential mechanism underlying the discordant clinical responses that are often observed in metastatic diseases.

A global live cell barcoding approach for multiplexed mass cytometry profiling of mouse tumors

With the advent of cancer immunology, mass cytometry has been increasingly employed to characterize the responses to cancer therapies and the tumor microenvironment (TME). One of its most notable applications is efficient multiplexing of samples into batches by dedicating a number of metal isotope channels to barcodes, enabling robust data acquisition and analysis. Barcoding is most effective when markers are present in all cells of interest. While CD45 has been shown to be a reliable marker for barcoding all immune cells in a given sample, a strategy to reliably barcode mouse cancer cells has not been demonstrated. To this end, we identified CD29 and CD98 as markers widely expressed by commonly used mouse cancer cell lines. We conjugated anti-CD29 and anti-CD98 antibodies to cadmium or indium metals and validated their utility in 10-plex barcoding of live cells. Finally, we established a potentially novel barcoding system incorporating the combination of CD29, CD98, and CD45 to multiplex 10 tumors from s.c. MC38 and KPC tumor models, while successfully recapitulating the known contrast in the PD1-PDL1 axis between the 2 models. The ability to barcode tumor cells along with immune cells empowers the interrogation of the tumor-immune interactions in mouse TME studies.

Feasibility and efficacy of neoadjuvant cabozantinib and nivolumab in patients with borderline resectable or locally advanced hepatocellular carcinoma (HCC)

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Background: Only 10-15% of newly diagnosed HCC patients are candidates for a potentially curative resection, and most patients who receive resection eventually recur. Historical systemic therapies including sorafenib, as well as locoregional therapies, have not demonstrated benefit in the perioperative setting. Novel combinations of targeted therapies and immunotherapies demonstrate higher response rates than sorafenib in HCC. Here, we report the feasibility and efficacy of neoadjuvant combination therapy with cabozantinib plus nivolumab, followed by surgical resection, in patients with borderline resectable or locally advanced HCC. Methods: We conducted an open-label, single-arm, phase I study in patients with HCC with borderline resectable or locally advanced HCC (including multinodular disease, portal vein involvement, or other high-risk features). Patients received 8 weeks of therapy with cabozantinib 40 mg oral daily plus nivolumab 240 mg IV every two weeks, followed by restaging and possible surgical resection. The primary endpoint was feasibility, defined by the percentage of patients experiencing a treatment-related adverse event that precluded continuing on to surgery within 60 days of the planned date for surgical evaluation. Results: We enrolled 15 patients of whom 14 patients completed neoadjuvant therapy and underwent surgical evaluation. Adverse events were consistent with prior experience with these agents, and the trial met its primary endpoint, with no patients experiencing a treatment-related adverse event that precluded timely surgical assessment. Of patients completing neoadjuvant therapy, 1 patient declined surgery, 1 tumor could not be resected, and 12 patients underwent successful R0 surgical resection. 5/12 (41.7%) resected patients had a major or complete pathologic response. At a median follow up of one year, 4/5 pathologic responders are without recurrence. We performed an in-depth profiling of the surgical resection biospecimens and identified an enrichment of IFNγ+ effector memory CD4+ and granzyme B+ effector CD8+ T cells as well as tertiary lymphoid aggregates in the pathologic responders. We further analyzed the spatial relationships of cell types in responders and non-responders, which identified distinct spatial arrangement of B cells in responders, and proximity of arginase-1 expressing myeloid cells to T cells in nonresponders. Conclusions: This study is, to our knowledge, the first use of a targeted therapy in combination with an immune checkpoint inhibitor in the neoadjuvant setting in HCC, and the first use of modern systemic therapies to expand surgical resection criteria. Neoadjuvant cabozantinib and nivolumab is feasible, and may result in pathologic responses and long-term disease-free survival in a group of patients who may be outside traditional resection criteria. Clinical trial information: NCT03299946.

The Intergenerational Impacts of Paternal Diet on DNA Methylation and Offspring Phenotypes in Sheep

Knowledge of non-genomic inheritance of traits is currently limited. Although it is well established that maternal diet influences offspring inheritance of traits through DNA methylation, studies on the impact of prepubertal paternal diet on DNA methylation are rare. This study aimed to evaluate the impact of prepubertal diet in Polypay rams on complex traits, DNA methylation, and transmission of traits to offspring. A total of 10 littermate pairs of F0 rams were divided so that one ram was fed a control diet, and the other was fed the control diet with supplemental methionine. Diet was associated with earlier age at puberty in treatment vs. control F0 rams. F0 treatment rams tended to show decreased pubertal weight compared to control rams; however, no differences were detected in overall growth. A total of ten F0 rams were bred, and the entire F1 generation was fed a control diet. Diet of F0 rams had a significant association with scrotal circumference (SC) and weight at puberty of F1 offspring. The paternal diet was not significantly associated with F1 ram growth or age at puberty. The DNA methylation of F0 ram sperm was assessed, and genes related to both sexual development (e.g., DAZAP1, CHD7, TAB1, MTMR2, CELSR1, MGAT1) and body weight (e.g., DUOX2, DUOXA2) were prevalent in the data. These results provide novel information about the mechanisms through which the prepubertal paternal diet may alter body weight at puberty and sexual development.

Age Dependency of the Prognostic Impact of Tumor Genomics in Localized Resectable MYCN-Nonamplified Neuroblastomas. Report From the SIOPEN Biology Group on the LNESG Trials and a COG Validation Group

For localized, resectable neuroblastoma without MYCN amplification, surgery only is recommended even if incomplete. However, it is not known whether the genomic background of these tumors may influence outcome.

Integration of whole-genome DNA methylation data with RNA sequencing data to identify markers for bull fertility

Predicting bull fertility prior to breeding is a current challenge for the dairy industry. The use of molecular biomarkers has been previously assessed. However, the integration of this information has not been performed to extract biologically relevant markers. The goal of this study was to integrate DNA methylation data with previously published RNA-sequencing results in order to identify candidate markers for sire fertility. A total of 1765 differentially methylated cytosines were found between high- and low-fertility sires. Ten genes associated with 11 differentially methylated cytosines were found in a previous study of gene expression between high- and low-fertility sires. Additionally, two of these genes code for proteins found exclusively in bull seminal plasma. Collectively, our results reveal 10 genes that could be used in the future as a panel for predicting bull fertility.

Alleged predisposing dietary factors fail to increase the incidence of osteochondrosis-like lesions in growing pigs at 14 and 24 wk of age

Early lesions of osteochondrosis (OC) are exhibited by regions of cartilage retention along the growth plate and articular cartilage. Progression of OC lesions may impair locomotion and necessitate euthanasia in adherence to animal welfare guides. Little is known about the role of nutrition in the initiation and early stages of OC. However, dietary components are commonly implicated as predisposing factors. In this study, diets were altered as an attempt to induce early stage OC lesions under controlled conditions. At 8 wk of age, 96 crossbred gilts (body weight [BW] = 17.4 ± 0.18 kg) were randomly assigned to one of four corn-soybean meal-based diets (four pens per diet, six pigs per pen) to assess diet effects on the number and volume of OC lesions in the distal femur. Diets included a non-pelleted control diet (Ctl); Ctl plus 20% glucose (Glc); the Ctl with increased concentrations of lysine, Ca, and P (+CaP); and the +CaP diet in a pelleted form (PEL). Femurs were collected from pigs euthanized at either 14-wk (Wk 14) or 24-wk (Wk 14) of age for assessments of OC lesions. Based on a mixed model analysis with pen as the experimental unit, dietary treatments did not affect final BW (129.3 ± 3.8 kg) or average daily gain (ADG) (1.00 ± 0.03 kg/d) over the trial. As expected, pigs fed PEL and Glc diets were more efficient (P < 0.05) in feed conversion compared with Ctl and +CaP. Using femurs as the experimental unit at Wk 14 (collected from two of the six pigs per pen), bone mineral content, determined by dual-energy x-ray absorptiometry scans, was greater (P < 0.05) in pigs fed +CaP and PEL than Ctl or Glc diets; however, only +CaP group differed (P < 0.05) at Wk 24 (collected from four pigs per pen). Computed tomography (CT) scans of femurs were reconstructed as three-dimensional images to allow detection of the number, volume, and surface area of lesions in distal growth plates. At Wk 14, pigs fed Ctl had fewer number of lesions (P < 0.05); however, no differences were detected among dietary treatments in lesion volume or lesion surface area. Pigs had fewer lesions at Wk 24 than Wk 14; however, differences were not detected among dietary treatments. At Wk 24, pigs fed Ctl diets had the greatest lesion volume among dietary treatments (P < 0.05). In conclusion, none of the pigs exhibited symptoms of lameness regardless of dietary treatment or OC lesion traits. Diet modifications due to pelleting or inclusion of rapidly digestible ingredients, such as glucose, did not increase prevalence or size of OC lesions. Image analysis of CT scans was a reliable method to quantify the number, size, and location of OC lesions.

Characterization and functional roles of paternal RNAs in 2-4 cell bovine embryos

Embryos utilize oocyte-donated RNAs until they become capable of producing RNAs through embryonic genome activation (EGA). The sperm's influence over pre-EGA RNA content of embryos remains unknown. Recent studies have revealed that sperm donate non-genomic components upon fertilization. Thus, sperm may also contribute to RNA presence in pre-EGA embryos. The first objective of this study was to investigate whether male fertility status is associated with the RNAs present in the bovine embryo prior to EGA. A total of 65 RNAs were found to be differentially expressed between 2-4 cell bovine embryos derived from high and low fertility sires. Expression patterns were confirmed for protein phosphatase 1 regulatory subunit 36 (PPP1R36) and ataxin 2 like (ATXN2L) in three new biological replicates. The knockdown of ATXN2L led to a 22.9% increase in blastocyst development. The second objective of this study was to characterize the parental origin of RNAs present in pre-EGA embryos. Results revealed 472 sperm-derived RNAs, 2575 oocyte-derived RNAs, 2675 RNAs derived from both sperm and oocytes, and 663 embryo-exclusive RNAs. This study uncovers an association of male fertility with developmentally impactful RNAs in 2-4 cell embryos. This study also provides an initial characterization of paternally-contributed RNAs to pre-EGA embryos. Furthermore, a subset of 2-4 cell embryo-specific RNAs was identified.

CHANGES IN THE FUNCTIONAL STATUS IN CHILDREN WITH CEREBRAL PALSY WHEN PERFORMING CYCLIC MOVEMENTS

Aim. The article aims at improving functional activity in children with cerebral palsy based on the features of adaptation to cyclic motions. Materials and methods. 23 children with cerebral palsy aged from 2 to 14 years participated in the study regardless of the form of disease. Functional shifts were assessed under the effect of cyclic load on the cardiovascular system. The following methods were used for the study: heart rate variability analysis based on the changes in total power spectrum (TPw, mc2), relative values of heart rate spectrum characteristics (HF%, LF%, VLF%), and the Stress Index (SI). Results. It was established that long-term hyponesia affected negatively hemodynamics in children with cerebral palsy and contributed to a decrease in adaptation mechanisms. The initial functional status of children with cerebral palsy was characterized by low values of adaptation reserves, aerobic power, and recovery potential. Adaptive capabilities in children when growing up from 3 to 12 years decrease to asthenization. Conclusion. Motor performance is the most effective factor influencing improvement of functional capabilities in children with cerebral capabilities. The movements of the cyclic type contribute to an increase in excitability and muscle lability, as well as to the development of general endurance.

Symposium review: Embryo survival-A genomic perspective of the other side of fertility

The majority of embryonic loss in cattle occurs within the first 3 to 4 wk of pregnancy, and there are currently no accurate predictors of pregnancy outcome. Existing embryo quality assessment methods include morphological evaluation and embryo biopsy. These methods are not accurate and carry some health risks to the developing embryo, respectively. Therefore, there is need to identify noninvasive biomarkers such as microRNA that can predict embryo quality and pregnancy outcome. Furthermore, researchers need a better understanding of the dynamic interaction between the mother and the embryo. The transcriptome of the uterus shows plasticity that depends on the embryo type so that the expression level of some genes for in vivo embryos would be different from that of in vitro-produced embryos. Similarly, the embryonic transcriptome and epigenome change in response to different environmental factors such as stress, diet, disease, and physiological status of the mother. This embryo-mother crosstalk could be better understood by investigating the molecular signaling that occurs at different stages of embryonic development. Although transcriptomics is a useful tool to assess the roles of genes and pathways in embryo quality and maternal receptivity, it does not provide the exact functions of these genes, and it shows correlation rather than causality. Therefore, an in-depth functional genomic analysis is needed for better understanding of the molecular mechanisms controlling embryo development. In this review, we discuss recent genomic technologies such as RNA interference, gapmer technology, and genome editing techniques used in humans and livestock to elucidate the molecular mechanisms of genes affecting embryo development.

Familial Coagulation Factor V Deficiency Caused by a Novel 4 Base Pair Insertion in the Factor V Gene: Factor V Stanford

An index patient with pseudohomozygosity for factor V Leiden was identified. Each of his two children inherited a different paternal factor V allele; a daughter was heterozygous for factor V Leiden, with 100% factor V activity, and a son was heterozygous for factor V deficiency, with 50% factor V activity. Genomic DNA was obtained from family members, and the 25 factor V exons and flanking intronic regions were sequenced in the proband and confirmed in the children. Within exon 13 of factor V, a 4 base insertion was found at NT 2856 in the proband and son, but not the daughter. This mutation, here designated factor V Stanford, results in a frameshift with loss of a thrombin activation site (R1545V) and premature termination of translation at amino acid 1560.

[Indications and technique for transconjunctival optic nerve sheath fenestration : Video article]

BACKGROUND

Placement of a ventricular shunt is the primary surgical procedure for lowering intracranial pressure in pseudotumor cerebri syndrome; however, if ophthalmological symptoms prevail over neurological symptoms or if there are no neurological symptoms at all, optic nerve sheath fenestration may be a valuable option for relief of pressure on the retrobulbar optic nerve when papilledema caused by pseudotumor cerebri syndrome threatens vision despite previous conservative measures.

METHODS

This review covers the indications, technique and results of optic nerve sheath fenestration compared to competing procedures based on a systematic literature search, analysis of own cases and a documentation of the surgical technique.

SURGICAL TECHNIQUE

After performing a medial transconjunctival orbitotomy the medial rectus muscle tendon is temporarily detached and the eye abducted by traction sutures. Using confocal illumination under a surgical microscope, the optic nerve can be visualized using orbital spatulas and the sheath can be punctured with a microscalpel. A video of this operation is available online.

CONCLUSION

Transconjunctival optic nerve sheath fenestration is a relatively safe method to reduce the rate of visual loss in pseudotumor cerebri syndrome. In selected cases it can be a useful alternative to ventriculoperitoneal/atrial shunts or venous stents.

Market Failures and Market Framings: Can a market be transformed from the inside?

How do actors innovate markets in cases of perceived market failures? This paper’s aim is to examine what happens when a market is innovated or, as we call it, ‘redevised’ in situations where public and commercial interests significantly diverge. Market devices can serve an important function in such attempts to innovate markets: they are material and/or social arrangements that are put into place to shape the market in question in certain ways. But can such devices really transform a market from within? To examine this question we trace the history of the Geneva Medicines Patent Pool, a civil society initiative introduced to change pharmaceutical firms’ licensing and collaboration practices in the market for HIV/AIDS medicines. Our empirical results indicate that redevising a market in response to market failures can shift the market’s frames and contribute to altering its practices, but that this is a pragmatic and often lengthy process that is never fully predictable in advance. By attending to the intended and unintended consequences - or misfires - of redevising a market, our study raises important questions around acting in and on the market, market innovation’s’ ontological impact, zooming in and zooming out when studying redevising, and attending to the temporality of market innovation.

Sexual Dimorphism of miRNAs Secreted by Bovine In vitro-produced Embryos

Sexual dimorphism of bovine blastocysts has previously been observed through differences in development, cell death, metabolism, telomere length, DNA methylation, and transcriptomics. However, dimorphism in the secretion of miRNAs to culture media has not yet been evaluated. The objectives of this study were to determine if sex-specific blastocyst miRNA secretion occurs and to further investigate the role these miRNAs may have in the interaction between a blastocyst and the maternal environment. In vitro embryo culture was performed and media from male and female blastocysts was collected into sex-specific pools. Profiling of 68 miRNAs revealed a total of eight miRNAs that were differentially expressed between female and male-conditioned media. Validation by qPCR confirmed higher expression of miR-22 (P < 0.05), miR-122 (P < 0.05), and miR-320a (P < 0.05) in female media for three additional biological replicates. To examine the potential roles of secreted miRNAs to the media in communication with the maternal environment, miR-22, miR-122, and miR-320a were each supplemented to four replicates of primary bovine endometrial epithelial cell culture. Uptake of miR-122 (P < 0.05) and miR-320a (P < 0.05) was detected, and a trend of uptake was detected for miR-22 (P > 0.05). Further, expression of the progesterone receptor transcript, a predicted target of all three miRNAs, was found to be upregulated in the cells following supplementation of miR-122 (P < 0.05) and miR-320a (P < 0.05), and a trend upregulation of the transcript was observed following miR-22 (P > 0.05) supplementation. This work demonstrates that male and female conceptuses are able to differentially secrete miRNAs at the blastocyst stage and that these miRNAs have the ability to induce a transcriptomic response when applied to maternal cells. This knowledge builds on the known dimorphic differences in conceptuses at the blastocyst stage and demonstrates a role for blastocyst-secreted miRNAs in cell-cell communication.

Aldehyde dehydrogenase activity plays a Key role in the aggressive phenotype of neuroblastoma

BACKGROUND

The successful targeting of neuroblastoma (NB) by associating tumor-initiating cells (TICs) is a major challenge in the development of new therapeutic strategies. The subfamily of aldehyde dehydrogenases 1 (ALDH1) isoenzymes, which comprises ALDH1A1, ALDH1A2, and ALDH1A3, is involved in the synthesis of retinoic acid, and has been identified as functional stem cell markers in diverse cancers. By combining serial neurosphere passages with gene expression profiling, we have previously identified ALDH1A2 and ALDH1A3 as potential NB TICs markers in patient-derived xenograft tumors. In this study, we explored the involvement of ALDH1 isoenzymes and the related ALDH activity in NB aggressive properties.

METHODS

ALDH activity and ALDH1A1/A2/A3 expression levels were measured using the ALDEFLUOR™ kit, and by real-time PCR, respectively. ALDH activity was inhibited using the specific ALDH inhibitor diethylaminobenzaldehyde (DEAB), and ALDH1A3 gene knock-out was generated through the CRISPR/Cas9 technology.

RESULTS

We first confirmed the enrichment of ALDH1A2 and ALDH1A3 mRNA expression in NB cell lines and patient-derived xenograft tumors during neurosphere passages. We found that high ALDH1A1 expression was associated with less aggressive NB tumors and cell lines, and correlated with favorable prognostic factors. In contrast, we observed that ALDH1A3 was more widely expressed in NB cell lines and was associated with poor survival and high-risk prognostic factors. We also identified an important ALDH activity in various NB cell lines and patient-derived xenograft tumors. Specific inhibition of ALDH activity with diethylaminobenzaldehyde (DEAB) resulted in a strong reduction of NB cell clonogenicity, and TIC self-renewal potential, and partially enhanced NB cells sensitivity to 4-hydroxycyclophosphamide. Finally, the specific knock-out of ALDH1A3 via CRISPR/Cas9 gene editing reduced NB cell clonogenicity, and mediated a cell type-dependent inhibition of TIC self-renewal properties.

CONCLUSIONS

Together our data uncover the participation of ALDH enzymatic activity in the aggressive properties and 4-hydroxycyclophosphamide resistance of NB, and show that the specific ALDH1A3 isoenzyme increases the aggressive capacities of a subset of NB cells.

Overexpression of PIK3CA in murine head and neck epithelium drives tumor invasion and metastasis through PDK1 and enhanced TGFβ signaling

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and metastasis as major causes of mortality. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis, and PIK3CA amplification and mutation are among the most common genetic alterations in human HNSCC. Compared to the well-documented roles of the PI3K pathway in cell growth and survival, the roles of the PI3K pathway in tumor invasion and metastasis have not been well delineated. We generated a PIK3CA-genetically engineered mouse model (PIK3CA-GEMM) in which wildtype PIK3CA is overexpressed in head and neck epithelium. Although PIK3CA overexpression alone was not sufficient to initiate HNSCC formation, it significantly increased tumor susceptibility in an oral-carcinogenesis mouse model. PIK3CA overexpression in mouse oral epithelium increased tumor invasiveness and metastasis by increasing epithelial-mesenchymal transition and by enriching a cancer stem cell phenotype in tumor epithelial cells. In addition to these epithelial alterations, we also observed marked inflammation in tumor stroma. AKT is a central signaling mediator of the PI3K pathway. However, molecular analysis suggested that progression of PIK3CA-driven HNSCC is facilitated by PDK1 and enhanced TGFβ signaling rather than by AKT. Examination of human HNSCC clinical samples revealed that both PIK3CA and PDK1 protein levels correlated with tumor progression, highlighting the significance of this pathway. In summary, our results offer significant insight into how PIK3CA-overexpression drives HNSCC invasion and metastasis, providing a rationale for targeting PI3K/PDK1 and TGFβ signaling in advanced HNSCC patients with PIK3CA amplification.

[Technique and Results for the Transconjunctival Removal of Orbital Haemangiomas]

BACKGROUND

The cavernous haemangioma (cavernoma) is the most common orbital tumour in adults. Various surgical approaches have been described so far. We prefer a transconjunctival approach and analyse herein how our outcomes compare with those of transcutaneous or transosseous approaches.

METHODS

A retrospective series of 10 cases was analysed with regard to surgical success and complications.

RESULTS

The tumour could be completely removed in all cases. In one case, preoperative diplopia disappeared after surgery. Another case suffered from postoperative diplopia, which resolved within two months. Two cases developed a long-lasting partial tonic pupil.

CONCLUSION

A retrobulbar cavernoma can be safely removed via a transconjunctival approach through shrinkage by coagulation and subsequent cryoextraction.

The CXCR4/CXCR7/CXCL12 Axis Is Involved in a Secondary but Complex Control of Neuroblastoma Metastatic Cell Homing

Neuroblastoma (NB) is one of the most deadly solid tumors of the young child, for which new efficient and targeted therapies are strongly needed. The CXCR4/CXCR7/CXCL12 chemokine axis has been involved in the progression and organ-specific dissemination of various cancers. In NB, CXCR4 expression was shown to be associated to highly aggressive undifferentiated tumors, while CXCR7 expression was detected in more differentiated and mature neuroblastic tumors. As investigated in vivo, using an orthotopic model of tumor cell implantation of chemokine receptor-overexpressing NB cells (IGR-NB8), the CXCR4/CXCR7/CXCL12 axis was shown to regulate NB primary and secondary growth, although without any apparent influence on organ selective metastasis. In the present study, we addressed the selective role of CXCR4 and CXCR7 receptors in the homing phase of metastatic dissemination using an intravenous model of tumor cell implantation. Tail vein injection into NOD-scid-gamma mice of transduced IGR-NB8 cells overexpressing CXCR4, CXCR7, or both receptors revealed that all transduced cell variants preferentially invaded the adrenal gland and typical NB metastatic target organs, such as the liver and the bone marrow. However, CXCR4 expression favored NB cell dissemination to the liver and the lungs, while CXCR7 was able to strongly promote NB cell homing to the adrenal gland and the liver. Finally, coexpression of CXCR4 and CXCR7 receptors significantly and selectively increased NB dissemination toward the bone marrow. In conclusion, CXCR4 and CXCR7 receptors may be involved in a complex and organ-dependent control of NB growth and selective homing, making these receptors and their inhibitors potential new therapeutic targets.

Wild-type ALK and activating ALK-R1275Q and ALK-F1174L mutations upregulate Myc and initiate tumor formation in murine neural crest progenitor cells

The anaplastic lymphoma kinase (ALK) gene is overexpressed, mutated or amplified in most neuroblastoma (NB), a pediatric neural crest-derived embryonal tumor. The two most frequent mutations, ALK-F1174L and ALK-R1275Q, contribute to NB tumorigenesis in mouse models, and cooperate with MYCN in the oncogenic process. However, the precise role of activating ALK mutations or ALK-wt overexpression in NB tumor initiation needs further clarification.

Human ALK-wt, ALK-F1174L, or ALK-R1275Q were stably expressed in murine neural crest progenitor cells (NCPC), MONC-1 or JoMa1, immortalized with v-Myc or Tamoxifen-inducible Myc-ER^T, respectively. While orthotopic implantations of MONC-1 parental cells in nude mice generated various tumor types, such as NB, osteo/chondrosarcoma, and undifferentiated tumors, due to v-Myc oncogenic activity, MONC-1-ALK-F1174L cells only produced undifferentiated tumors. Furthermore, our data represent the first demonstration of ALK-wt transforming capacity, as ALK-wt expression in JoMa1 cells, likewise ALK-F1174L, or ALK-R1275Q, in absence of exogenous Myc-ER^T activity, was sufficient to induce the formation of aggressive and undifferentiated neural crest cell-derived tumors, but not to drive NB development. Interestingly, JoMa1-ALK tumors and their derived cell lines upregulated Myc endogenous expression, resulting from ALK activation, and both ALK and Myc activities were necessary to confer tumorigenic properties on tumor-derived JoMa1 cells in vitro.

Assessment of the chemosensitizing activity of TAT-RasGAP317-326 in childhood cancers

Although current anti-cancer protocols are reasonably effective, treatment-associated long-term side effects, induced by lack of specificity of the anti-cancer procedures, remain a challenging problem in pediatric oncology. TAT-RasGAP317-326 is a RasGAP-derived cell-permeable peptide that acts as a sensitizer to various anti-cancer treatments in adult tumor cells. In the present study, we assessed the effect of TAT-RasGAP317-326 in several childhood cancer cell lines. The RasGAP-derived peptide-induced cell death was analyzed in several neuroblastoma, Ewing sarcoma and leukemia cell lines (as well as in normal lymphocytes). Cell death was evaluated using flow cytometry methods in the absence or in the presence of the peptide in combination with various genotoxins used in the clinics (4-hydroperoxycyclophosphamide, etoposide, vincristine and doxorubicin). All tested pediatric tumors, in response to at least one genotoxin, were sensitized by TAT-RasGAP317-326. The RasGAP-derived peptide did not increase cell death of normal lymphocytes, alone or in combination with the majority of the tested chemotherapies. Consequently, TAT-RasGAP317-326 may benefit children with tumors by increasing the efficacy of anti-cancer therapies notably by allowing reductions in anti-cancer drug dosage and the associated drug-induced side effects.

Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification

Background:

The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis.

Methods:

To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol.

Results:

Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients between 12 and 18 months and over 18 months of age at diagnosis, respectively (P=0.04). A significant correlation (P=0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS=46% vs 75%, P=0.023; OS=66.8% vs 100%, P=0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P=0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P=0.018).

Conclusions:

The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.

Abstract B59: Wild-type ALK and both ALK-R1275Q and ALK-F1174L activating mutations display a strong oncogenic activity in vivo in murine neural crest progenitor cells via cooperation with c-myc

Neuroblastoma (NB), a neural crest-derived embryonal tumor, is a heterogeneous childhood malignancy that often presents as an incurable disease. The anaplastic lymphoma receptor tyrosine kinase gene (ALK) was shown to be overexpressed, mutated or amplified in the majority of NB. The most common mutation, ALK-F1174L displayed an efficient transforming activity in vivo, and was shown in transgenic mouse models to drive NB formation and to cooperate with MYCN in the oncogenic process. In this project, we aimed at comparing the in vivo oncogenic potential of ALK-wt, with the two most frequent activating mutations ALK-F1174L (only present in sporadic NB), and ALK-R1275Q (present in familial and sporadic NB). Our strategy included the stable expression of ALK-wt and mutated variants into murine neural crest progenitor cells (JoMa1), which are the well-recognized NB progenitors.

In vitro, only ALK-F1174L and ALK-R1275Q conferred an oncogenic potential to JoMa1 cells as measured by clonogenic assays. In contrast, in vivo experiments showed that JoMa1 cells expressing ALK-wt, as well as activating mutations ALK-R1275Q and ALK-F1174L rapidly produced highly aggressive tumors after subcutaneous or orthotopic (adrenal gland) implantations in nude mice. JoMa1-ALK-F1174L cells induced the fastest tumor growth as compared to JoMa1-ALK-R1275Q and JoMa1-ALK-wt cells, revealing the tremendous tumorigenic potential of ALK-F1174L cells. Interestingly, as a result from ALK activation, orthotopic tumors or their derived cell lines strongly upregulated c-myc expression. Moreover, specific ALK inhibition using TAE684, or c-myc inhibition with 10058-F4, completely abrogated the in vitro clonogenic capacity of tumor-derived cell lines. Such observations suggest that the tumorigenic potential of neural crest progenitor cells is strongly dependent on both ALK and c-myc activity.

Our study demonstrates for the first time an oncogenic activity of ALK-R1275Q and ALK-wt when overexpressed in neural crest cells, and reveals the complex interactions between ALK and the myc oncogene family in neural crest cell-derived tumor formation.

Citation Format: Annick Mühlethaler-Mottet, Gisèle Montavon, Marjorie Flahaut, Nicolas Jauquier, Jean-Marc Joseph, Olivier Delattre, Lukas Sommer, Isabelle Janoueix-Lerosey, Nicole Gross. Wild-type ALK and both ALK-R1275Q and ALK-F1174L activating mutations display a strong oncogenic activity in vivo in murine neural crest progenitor cells via cooperation with c-myc. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B59.

Novel agents targeting the IGF-1R/PI3K pathway impair cell proliferation and survival in subsets of medulloblastoma and neuroblastoma

The receptor tyrosine kinase (RTK)/phosphoinositide 3-kinase (PI3K) pathway is fundamental for cancer cell proliferation and is known to be frequently altered and activated in neoplasia, including embryonal tumors. Based on the high frequency of alterations, targeting components of the PI3K signaling pathway is considered to be a promising therapeutic approach for cancer treatment. Here, we have investigated the potential of targeting the axis of the insulin-like growth factor-1 receptor (IGF-1R) and PI3K signaling in two common cancers of childhood: neuroblastoma, the most common extracranial tumor in children and medulloblastoma, the most frequent malignant childhood brain tumor. By treating neuroblastoma and medulloblastoma cells with R1507, a specific humanized monoclonal antibody against the IGF-1R, we could observe cell line-specific responses and in some cases a strong decrease in cell proliferation. In contrast, targeting the PI3K p110α with the specific inhibitor PIK75 resulted in broad anti-proliferative effects in a panel of neuro- and medulloblastoma cell lines. Additionally, sensitization to commonly used chemotherapeutic agents occurred in neuroblastoma cells upon treatment with R1507 or PIK75. Furthermore, by studying the expression and phosphorylation state of IGF-1R/PI3K downstream signaling targets we found down-regulated signaling pathway activation. In addition, apoptosis occurred in embryonal tumor cells after treatment with PIK75 or R1507. Together, our studies demonstrate the potential of targeting the IGF-1R/PI3K signaling axis in embryonal tumors. Hopefully, this knowledge will contribute to the development of urgently required new targeted therapies for embryonal tumors.

RNA interference screening identifies a novel role for autocrine fibroblast growth factor signaling in neuroblastoma chemoresistance

Chemotherapeutic drug resistance is one of the major causes for treatment failure in high-risk neuroblastoma (NB), the most common extra cranial solid tumor in children. Poor prognosis is typically associated with MYCN amplification. Here, we utilized a loss-of-function kinome-wide RNA interference screen to identify genes that cause cisplatin sensitization. We identified fibroblast growth factor receptor 2 (FGFR2) as an important determinant of cisplatin resistance. Pharmacological inhibition of FGFR2 confirmed the importance of this kinase in NB chemoresistance. Silencing of FGFR2 sensitized NB cells to cisplatin-induced apoptosis, which was regulated by the downregulation of the anti-apoptotic proteins BCL2 and BCLXL. Mechanistically, FGFR2 was shown to activate protein kinase C-δ to induce BCL2 expression. FGFR2, as well as the ligand fibroblast growth factor-2, were consistently expressed in primary NB and NB cell lines, indicating the presence of an autocrine loop. Expression analysis revealed that FGFR2 correlates with MYCN amplification and with advanced stage disease, demonstrating the clinical relevance of FGFR2 in NB. These findings suggest a novel role for FGFR2 in chemoresistance and provide a rational to combine pharmacological inhibitors against FGFR2 with chemotherapeutic agents for the treatment of NB.

Automated frequency domain analysis of oxygen saturation as a screening tool for SAHS

Sleep apnea-hypopnea syndrome (SAHS) is significantly underdiagnosed and new screening systems are needed. The analysis of oxygen desaturation has been proposed as a screening method. However, when oxygen saturation (SpO(2)) is used as a standalone single channel device, algorithms working in time domain achieve either a high sensitivity or a high specificity, but not usually both. This limitation arises from the dependence of time-domain analysis on absolute SpO(2) values and the lack of standardized thresholds defined as pathological. The aim of this study is to assess the degree of concordance between SAHS screening using offline frequency domain processing of SpO(2) signals and the apnea-hypopnea index (AHI), and the diagnostic performance of such a new method. SpO(2) signals from 115 subjects were analyzed. Data were divided in a training data set (37) and a test set (78). Power spectral density was calculated and related to the desaturation index scored by physicians. A frequency desaturation index (FDI) was then estimated and its accuracy compared to the classical desaturation index and to the apnea-hypopnea index. The findings point to a high diagnostic agreement: the best sensitivity and specificity values obtained were 83.33% and 80.44%, respectively. Moreover, the proposed method does not rely on absolute SpO(2) values and is highly robust to artifacts.

Individual caspase-10 isoforms play distinct and opposing roles in the initiation of death receptor-mediated tumour cell apoptosis

The cysteine protease caspase-8 is an essential executioner of the death receptor (DR) apoptotic pathway. The physiological function of its homologue caspase-10 remains poorly understood, and the ability of caspase-10 to substitute for caspase-8 in the DR apoptotic pathway is still controversial. Here, we analysed the particular contribution of caspase-10 isoforms to DR-mediated apoptosis in neuroblastoma (NB) cells characterised by their resistance to DR signalling. Silencing of caspase-8 in tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)-sensitive NB cells resulted in complete resistance to TRAIL, which could be reverted by overexpression of caspase-10A or -10D. Overexpression experiments in various caspase-8-expressing tumour cells also demonstrated that caspase-10A and -10D isoforms strongly increased TRAIL and FasL sensitivity, whereas caspase-10B or -10G had no effect or were weakly anti-apoptotic. Further investigations revealed that the unique C-terminal end of caspase-10B was responsible for its degradation by the ubiquitin-proteasome pathway and for its lack of pro-apoptotic activity compared with caspase-10A and -10D. These data highlight in several tumour cell types, a differential pro- or anti-apoptotic role for the distinct caspase-10 isoforms in DR signalling, which may be relevant for fine tuning of apoptosis initiation.

Influence of neuroblastoma stage on serum-based detection of MYCN amplification

BACKGROUND

MYCN oncogene amplification has been defined as the most important prognostic factor for neuroblastoma (NB), the most common solid extracranial neoplasm in children. High copy numbers are strongly associated with rapid tumor progression and poor outcome, independently of tumor stage or patient age, and this has become an important factor in treatment stratification.

PROCEDURE

By real-time quantitative PCR analysis, we evaluated the clinical relevance of circulating MYCN DNA of 267 patients with locoregional or metastatic NB in children less than 18 months of age.

RESULTS

For patients in this age group with INSS stage 4 or 4S NB and stage 3 patients, serum-based determination of MYCN DNA sequences had good sensitivity (85%, 83%, and 75% respectively) and high specificity (100%) when compared to direct tumor gene determination. In contrast, the approach showed low sensitivity patients with stages 1 and 2 disease.

CONCLUSION

Our results show that the sensitivity of the serum-based MYCN DNA sequence determination depends on the stage of the disease. However, this simple, reproducible assay may represent a reasonably sensitive and very specific tool to assess tumor MYCN status in cases with stage 3 and metastatic disease for whom a wait and see strategy is often recommended.

Poincaré analysis of an overnight arterial oxygen saturation signal applied to the diagnosis of sleep apnea hypopnea syndrome

The analysis of oxygen desaturations is a basic variable in polysomnographic studies for the diagnosis of sleep apnea. Several algorithms operating in the time domain already exist for sleep apnea detection via pulse oximetry, but in a disadvantageous way--they achieve either a high sensitivity or a high specificity. The aim of this study was to assess whether an alternative analysis of arterial oxygen saturation (SaO2) signals from overnight pulse oximetry could yield essential information on the diagnosis of sleep apnea hypopnea syndrome (SAHS). SaO2 signals from 117 subjects were analyzed. The population was divided into a learning dataset (70 patients) and a test set (47 patients). The learning set was used for tuning thresholds among the applied Poincaré quantitative descriptors. Results showed that the presence of apnea events in SAHS patients caused an increase in the SD1 Poincaré parameter. This conclusion was assessed prospectively using the test dataset. 90.9% sensitivity and 84.0% specificity were obtained in the test group. We conclude that Poincaré analysis could be useful in the study of SAHS, contributing to reduce the demand for polysomnographic studies in SAHS screening.

Fenretinide-induced caspase-8 activation and apoptosis in an established model of metastatic neuroblastoma

BACKGROUND

Resistance of high-risk metastatic neuroblastoma (HR-NB) to high dose chemotherapy (HD-CT) raises a major therapeutic challenge in pediatric oncology. Patients are treated by maintenance CT. For some patients, an adjuvant retinoid therapy is proposed, such as the synthetic retinoid fenretinide (4-HPR), an apoptotic inducer. Recent studies demonstrated that NB metastasis process is enhanced by the loss of caspase-8 involved in the Integrin-Mediated Death (IMD) process. As the role of caspase-8 appears to be critical in preventing metastasis, we aimed at studying the effect of 4-HPR on caspase-8 expression in metastatic neuroblasts.

METHODS

We used the human IGR-N-91 MYCN-amplified NB experimental model, able to disseminate in vivo from the primary nude mouse tumor xenograft (PTX) into myocardium (Myoc) and bone marrow (BM) of the animal. NB cell lines, i.e., IGR-N-91 and SH-EP, were treated with various doses of Fenretinide (4-HPR), then cytotoxicity was analyzed by MTS proliferation assay, apoptosis by the propidium staining method, gene or protein expressions by RT-PCR and immunoblotting and caspases activity by colorimetric protease assays.

RESULTS

The IGR-N-91 parental cells do not express detectable caspase-8. However the PTX cells established from the primary tumor in the mouse, are caspase-8 positive. In contrast, metastatic BM and Myoc cells show a clear down-regulation of the caspase-8 expression. In parallel, the caspases -3, -9, -10, Bcl-2, or Bax expressions were unchanged. Our data show that in BM, compared to PTX cells, 4-HPR up-regulates caspase-8 expression that parallels a higher sensitivity to apoptotic cell death. Stable caspase-8-silenced SH-EP cells appear more resistant to 4-HPR-induced cell death compared to control SH-EP cells. Moreover, 4-HPR synergizes with drugs since apoptosis is restored in VP16- or TRAIL-resistant-BM cells. These results demonstrate that 4-HPR in up-regulating caspase-8 expression, restores and induces apoptotic cell death in metastatic neuroblasts through caspase-8 activation.

CONCLUSION

This study provides basic clues for using fenretinide in clinical treatment of HR-NB patients. Moreover, since 4-HPR induces cell death in caspase-8 negative NB, it also challenges the concept of including 4-HPR in the induction of CT of these patients.

Chemokines in neuroectodermal cancers: the crucial growth signal from the soil

Although chemokines and their receptors were initially identified as regulators of cell trafficking during inflammation and immune response, they have emerged as crucial players in all stages of tumor development, primary growth, migration, angiogenesis, and establishment as metastases in distant target organs. Neuroectodermal tumors regroup neoplasms originating from the embryonic neural crest cells, which display clinical and biological similarities. These tumors are highly malignant and rapidly progressing diseases that disseminate to similar target organs such as bone marrow, bone, liver and lungs. There is increasing evidence that interaction of several chemokine receptors with corresponding chemokine ligands are implicated in the growth and invasive characteristics of these tumors. In this review we summarize the current knowledge on the role of CXCL12 chemokine and its CXCR4 and CXCR7 receptors in the progression and survival of neuroectodermal tumors, with particular emphasis on neuroblastoma, the most typical and enigmatic neuroectodermal childhood tumor.

Complex molecular mechanisms cooperate to mediate histone deacetylase inhibitors anti-tumour activity in neuroblastoma cells

Background

Histone deacetylase inhibitors (HDACi) are a new class of promising anti-tumour agent inhibiting cell proliferation and survival in tumour cells with very low toxicity toward normal cells. Neuroblastoma (NB) is the second most common solid tumour in children still associated with poor outcome in higher stages and, thus NB strongly requires novel treatment modalities.

Results

We show here that the HDACi Sodium Butyrate (NaB), suberoylanilide hydroxamic acid (SAHA) and Trichostatin A (TSA) strongly reduce NB cells viability. The anti-tumour activity of these HDACi involved the induction of cell cycle arrest in the G2/M phase, followed by the activation of the intrinsic apoptotic pathway, via the activation of the caspases cascade. Moreover, HDACi mediated the activation of the pro-apoptotic proteins Bid and Bim_EL and the inactivation of the anti-apoptotic proteins XIAP, Bcl-x_L, RIP and survivin, that further enhanced the apoptotic signal. Interestingly, the activity of these apoptosis regulators was modulated by several different mechanisms, either by caspases dependent proteolytic cleavage or by degradation via the proteasome pathway. In addition, HDACi strongly impaired the hypoxia-induced secretion of VEGF by NB cells.

Conclusion

HDACi are therefore interesting new anti-tumour agents for targeting highly malignant tumours such as NB, as these agents display a strong toxicity toward aggressive NB cells and they may possibly reduce angiogenesis by decreasing VEGF production by NB cells.