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

Acknowledgements We thank all members of the SEQanswers forums for helpful advice; Steven Salzberg and Cole Trapnell for continuous support with the ‘Tuxedo’ suite; and the UCSC Genome team members. Sequencing was performed by the GenomEast platform, a member of the ‘France Génomique’ consortium (ANR-10-INBS-0009). We thank Ms Linda Robertson, Ms Margaret Fraser, Ms Samantha Flannigan (University of Aberdeen) and the staff at Grampian NHS Pregnancy Counselling Service and all the staff of the Department of Obstetrics and Gynecology of the Rennes Sud Hospital for their expert assistance and help, and the participating women, without whom this study would not have been possible. The authors are grateful for Ms Gersende Lacombe and Mr Laurent Deleurme from the Biosit CytomeTri cytometry core facility of Rennes 1 University. Funding French National Institute of Health and Medical Research (Inserm); University of Rennes 1; French School of Public Health (EHESP); 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]; Medical Research Council [MR/L010011/1 to PAF]; European Community’s Seventh Framework Programme (FP7/2007–2013) [under grant agreement no 212885 to PAF]; European Union’s Horizon 2020 Research and Innovation Programme [under grant agreement no 825100 to P.A.F. and S.M.G.].Peer reviewedPostprin

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

International audienceDevelopment 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 Ca 2+ 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 Ca 2+ channel-dependent cancer cell migration, we are still far from having a comprehensive vision of the Ca 2+ 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 Ca 2+ channel-dependent signaling in the regulation of these dynamic degradative structures. It will present available data on the few Ca 2+ channels that have been studied in that specific context and discuss some potential interesting actors that have not been fully explored yet

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

International audienceCONTEXT: 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 10-12 DW ovaries induced cell death and decreased KI67-positive cell density independently of fetal age. APAP targeted sub-populations 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 10-12 DW window of heightened sensitivity. Overall, APAP behaves as an endocrine disruptor in the fetal human ovary

The mechanosensitive TRPV2 calcium channel controls human melanoma invasiveness and metastatic potential

ABSTRACT Discovery of therapeutic targets against metastasis is of primary importance since being the main cause of cancer-related death. Melanoma is a highly aggressive cancer endowed with a unique capacity of rapidly metastasizing. Deregulation of calcium homeostasis has been involved in numerous cellular metastatic behaviors, although the molecular determinants supporting these processes often remain unclear. Here, we evidenced a prominent expression of the plasma membrane TRPV2 calcium channel as a distinctive feature of melanoma tumors, directly related to melanoma metastatic progression and dissemination. In vitro as well as in vivo , TRPV2 activity was sufficient to confer both migratory and invasive phenotypes to non-invasive melanoma cells, while conversely upon TRPV2 silencing, highly metastatic melanoma cells failed to retain their malignant behaviors. We established a model whereupon activation of the mechanosensitive TRPV2 channel, localized in highly dynamic nascent adhesion clusters, directly regulates calpain-dependent cleavage of the adhesive protein talin together with F-actin network. By operating at the crossroad of the tumor microenvironment and the intracellular machinery, mechanosensitive TRPV2 channel controls melanoma cells aggressiveness. Finally in human melanoma tumor samples, TRPV2 overexpression represents a molecular marker of advanced malignancy and bad prognosis, highlighting a new therapeutic option for migrastatics in the treatment of metastatic melanoma. Significance One essential feature of metastatic cells is enhanced motility and invasiveness. This study evidences TRPV2 channel control over metastatic melanoma invasiveness, highlights new migration regulatory mechanisms, and reveals this channel as a biomarker and migrastatic target for the treatment of advanced melanoma

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

International audienceAcetaminophen, 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

Role of HPV E6 proteins in preventing UVB-induced release of pro-apoptotic factors from the mitochondria.

Apoptotic elimination of UV-damaged cells from the epidermis is an important step in preventing both the emergence and expansion of cells with carcinogenic potential. A pivotal event in apoptosis is the release of apoptogenic factors from the mitochondria, although the mechanisms by which the different proteins are released are not fully understood. Here we demonstrate that UV radiation induced the mitochondrial to nuclear translocation of apoptosis inducing factor (AIF) in normal skin. The human papillomavirus (HPV) E6 protein prevented release of AIF and other apoptotic factors such as cytochrome c and Omi from mitochondria of UV-damaged primary epidermal keratinocytes and preserved mitochondrial integrity. shRNA silencing of Bak, a target for E6-mediated proteolysis, demonstrated the requirement of Bak for UV-induced AIF release and mitochondrial fragmentation. Furthermore, screening non-melanoma skin cancer biopsies revealed an inverse correlation between HPV status and AIF nuclear translocation. Our results indicate that the E6 activity towards Bak is a key factor that promotes survival of HPV-infected cells that facilitates tumor development