The mechanosensitive TRPV2 calcium channel promotes human melanoma invasiveness and metastatic potential.

Melanoma is a highly aggressive cancer endowed with a unique capacity of rapidly metastasizing, which is fundamentally driven by aberrant cell motility behaviors. Discovering "migrastatics" targets, specifically controlling invasion and dissemination of melanoma cells during metastasis, is therefore of primary importance. Here, we uncover the prominent expression of the plasma membrane TRPV2 calcium channel as a distinctive feature of melanoma tumors, directly related to melanoma metastatic dissemination. In vitro as well as in vivo, TRPV2 activity is sufficient to confer both migratory and invasive potentials, while conversely TRPV2 silencing in highly metastatic melanoma cells prevents aggressive behavior. In invasive melanoma cells, TRPV2 channel localizes at the leading edge, in dynamic nascent adhesions, and regulates calcium-mediated activation of calpain and the ensuing cleavage of the adhesive protein talin, along with F-actin organization. In human melanoma tissues, TRPV2 overexpression correlates with advanced malignancy and poor prognosis, evoking a biomarker potential. Hence, by regulating adhesion and motility, the mechanosensitive TRPV2 channel controls melanoma cell invasiveness, highlighting a new therapeutic option for migrastatics in the treatment of metastatic melanoma.

Acetaminophen (APAP, Paracetamol) Interferes With the First Trimester Human Fetal Ovary Development in an Ex Vivo Model.

CONTEXT: Acetaminophen (APAP, paracetamol) is widely used by pregnant women. Although long considered safe, growing evidence indicates that APAP is an endocrine disruptor since in utero exposure may be associated with a higher risk of male genital tract abnormalities. In rodents, fetal exposure has long-term effects on the reproductive function of female offspring. Human studies have also suggested harmful APAP exposure effects. OBJECTIVE: Given that disruption of fetal ovarian development may impact women's reproductive health, we investigated the effects of APAP on fetal human ovaries in culture. DESIGN AND SETTING: Human ovarian fragments from 284 fetuses aged 7 to 12 developmental weeks (DW) were cultivated ex vivo for 7 days in the presence of human-relevant concentrations of APAP (10-8 to 10-3 M) or vehicle control. MAIN OUTCOME MEASURES: Outcomes included examination of postculture tissue morphology, cell viability, apoptosis, and quantification of hormones, APAP, and APAP metabolites in conditioned culture media. RESULTS: APAP reduced the total cell number specifically in 10- to 12-DW ovaries, induced cell death, and decreased KI67-positive cell density independently of fetal age. APAP targeted subpopulations of germ cells and disrupted human fetal ovarian steroidogenesis, without affecting prostaglandin or inhibin B production. Human fetal ovaries were able to metabolize APAP. CONCLUSIONS: Our data indicate that APAP can impact first trimester human fetal ovarian development, especially during a 10- to 12-DW window of heightened sensitivity. Overall, APAP behaves as an endocrine disruptor in the fetal human ovary.

Exposure of human fetal kidneys to mild analgesics interferes with early nephrogenesis.

Acetaminophen, aspirin, and ibuprofen are mild analgesics commonly used by pregnant women, the sole current recommendation being to avoid ibuprofen from the fifth month of gestation. The nephrotoxicity of these three analgesics is well documented in adults, as is their interference with prostaglandins biosynthesis. Here we investigated the effect of these analgesics on human first trimester kidneys ex vivo. We first evaluated prostaglandins biosynthesis functionality by performing a wide screening of prostaglandin expression patterns in first trimester human kidneys. We demonstrated that prostaglandins biosynthesis machinery is functional during early nephrogenesis. Human fetal kidney explants aged 7-12 developmental weeks were exposed ex vivo to ibuprofen, aspirin or acetaminophen for 7 days, and analyzed by histology, immunohistochemistry, and flow cytometry. This study has revealed that these analgesics induced a spectrum of abnormalities within early developing structures, ranging from cell death to a decline in differentiating glomeruli density. These results warrant caution for the use of these medicines during the first trimester of pregnancy.

Insights and perspectives on calcium channel functions in the cockpit of cancerous space invaders.

Development of metastasis causes the most serious clinical consequences of cancer and is responsible for over 90 % of cancer-related deaths. Hence, a better understanding of the mechanisms that drive metastasis formation appears critical for drug development designed to prevent the spread of cancer and related mortality. Metastasis dissemination is a multistep process supported by the increased motility and invasiveness capacities of tumor cells. To succeed in overcoming the mechanical constraints imposed by the basement membrane and surrounding tissues, cancer cells reorganize their focal adhesions or extend acto-adhesive cellular protrusions, called invadosomes, that can both contact the extracellular matrix and tune its degradation through metalloprotease activity. Over the last decade, accumulating evidence has demonstrated that altered Ca2+ channel activities and/or expression promote tumor cell-specific phenotypic changes, such as exacerbated migration and invasion capacities, leading to metastasis formation. While several studies have addressed the molecular basis of Ca2+ channel-dependent cancer cell migration, we are still far from having a comprehensive vision of the Ca2+ channel-regulated mechanisms of migration/invasion. This is especially true regarding the specific context of invadosome-driven invasion. This review aims to provide an overview of the current evidence supporting a central role for Ca2+ channel-dependent signaling in the regulation of these dynamic degradative structures. It will present available data on the few Ca2+ channels that have been studied in that specific context and discuss some potential interesting actors that have not been fully explored yet.

Dynamics of the transcriptional landscape during human fetal testis and ovary development.

STUDY QUESTION: Which transcriptional program triggers sex differentiation in bipotential gonads and downstream cellular events governing fetal testis and ovary development in humans? SUMMARY ANSWER: The characterization of a dynamically regulated protein-coding and non-coding transcriptional landscape in developing human gonads of both sexes highlights a large number of potential key regulators that show an early sexually dimorphic expression pattern. WHAT IS KNOWN ALREADY: Gonadal sex differentiation is orchestrated by a sexually dimorphic gene expression program in XX and XY developing fetal gonads. A comprehensive characterization of its non-coding counterpart offers promising perspectives for deciphering the molecular events underpinning gonad development and for a complete understanding of the etiology of disorders of sex development in humans. STUDY DESIGN, SIZE, DURATION: To further investigate the protein-coding and non-coding transcriptional landscape during gonad differentiation, we used RNA-sequencing (RNA-seq) and characterized the RNA content of human fetal testis (N = 24) and ovaries (N = 24) from 6 to 17 postconceptional week (PCW), a key period in sex determination and gonad development. PARTICIPANTS/MATERIALS, SETTING, METHODS: First trimester fetuses (6-12 PCW) and second trimester fetuses (13-14 and 17 PCW) were obtained from legally induced normally progressing terminations of pregnancy. Total RNA was extracted from whole human fetal gonads and sequenced as paired-end 2 × 50 base reads. Resulting sequences were mapped to the human genome, allowing for the assembly and quantification of corresponding transcripts. MAIN RESULTS AND THE ROLE OF CHANCE: This RNA-seq analysis of human fetal testes and ovaries at seven key developmental stages led to the reconstruction of 22 080 transcripts differentially expressed during testicular and/or ovarian development. In addition to 8935 transcripts displaying sex-independent differential expression during gonad development, the comparison of testes and ovaries enabled the discrimination of 13 145 transcripts that show a sexually dimorphic expression profile. The latter include 1479 transcripts differentially expressed as early as 6 PCW, including 39 transcription factors, 40 long non-coding RNAs and 20 novel genes. Despite the use of stringent filtration criteria (expression cut-off of at least 1 fragment per kilobase of exon model per million reads mapped, fold change of at least 2 and false discovery rate adjusted P values of less than <1%), the possibility of assembly artifacts and of false-positive differentially expressed transcripts cannot be fully ruled out. LARGE-SCALE DATA: Raw data files (fastq) and a searchable table (.xlss) containing information on genomic features and expression data for all refined transcripts have been submitted to the NCBI GEO under accession number GSE116278. LIMITATIONS, REASONS FOR CAUTION: The intrinsic nature of this bulk analysis, i.e. the sequencing of transcripts from whole gonads, does not allow direct identification of the cellular origin(s) of the transcripts characterized. Potential cellular dilution effects (e.g. as a result of distinct proliferation rates in XX and XY gonads) may account for a few of the expression profiles identified as being sexually dimorphic. Finally, transcriptome alterations that would result from exposure to pre-abortive drugs cannot be completely excluded. Although we demonstrated the high quality of the sorted cell populations used for experimental validations using quantitative RT-PCR, it cannot be totally excluded that some germline expression may correspond to cell contamination by, for example, macrophages. WIDER IMPLICATIONS OF THE FINDINGS: For the first time, this study has led to the identification of 1000 protein-coding and non-coding candidate genes showing an early, sexually dimorphic, expression pattern that have not previously been associated with sex differentiation. Collectively, these results increase our understanding of gonad development in humans, and contribute significantly to the identification of new candidate genes involved in fetal gonad differentiation. The results also provide a unique resource that may improve our understanding of the fetal origin of testicular and ovarian dysgenesis syndromes, including cryptorchidism and testicular cancers. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the French National Institute of Health and Medical Research (Inserm), the University of Rennes 1, the French School of Public Health (EHESP), the Swiss National Science Foundation [SNF n° CRS115_171007 to B.J.], the French National Research Agency [ANR n° 16-CE14-0017-02 and n° 18-CE14-0038-02 to F.C.], the Medical Research Council [MR/L010011/1 to P.A.F.] and the European Community's Seventh Framework Programme (FP7/2007-2013) [under grant agreement no 212885 to P.A.F.] and from the European Union's Horizon 2020 Research and Innovation Programme [under grant agreement no 825100 to P.A.F. and S.M.G.]. There are no competing interests related to this study.

Sibiriline, a new small chemical inhibitor of receptor-interacting protein kinase 1, prevents immune-dependent hepatitis.

Necroptosis is a regulated form of cell death involved in several disease models including in particular liver diseases. Receptor-interacting protein kinases, RIPK1 and RIPK3, are the main serine/threonine kinases driving this cell death pathway. We screened a noncommercial, kinase-focused chemical library which allowed us to identify Sibiriline as a new inhibitor of necroptosis induced by tumor necrosis factor (TNF) in Fas-associated protein with death domain (FADD)-deficient Jurkat cells. Moreover, Sib inhibits necroptotic cell death induced by various death ligands in human or mouse cells while not protecting from caspase-dependent apoptosis. By using competition binding assay and recombinant kinase assays, we demonstrated that Sib is a rather specific competitive RIPK1 inhibitor. Molecular docking analysis shows that Sib is trapped closed to human RIPK1 adenosine triphosphate-binding site in a relatively hydrophobic pocket locking RIPK1 in an inactive conformation. In agreement with its RIPK1 inhibitory property, Sib inhibits both TNF-induced RIPK1-dependent necroptosis and RIPK1-dependent apoptosis. Finally, Sib protects mice from concanavalin A-induced hepatitis. These results reveal the small-molecule Sib as a new RIPK1 inhibitor potentially of interest for the treatment of immune-dependent hepatitis.