Publications by authors named "Natascha Pigat"

Benign prostate hyperplasia (BPH) is caused by the nonmalignant enlargement of the transition zone of the prostate gland, leading to lower urinary tract symptoms. Although current medical treatments are unsatisfactory in many patients, the limited understanding of the mechanisms driving disease progression prevents the development of alternative therapeutic strategies. The probasin-prolactin (Pb-PRL) transgenic mouse recapitulates many histopathological features of human BPH.

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Prostate cancer (PCa) represents one of the most frequent diagnosed cancer in males worldwide. Due to routine screening tests and the efficiency of available treatments, PCa-related deaths have significantly decreased over the past decades. However, PCa remains a critical threat if detected at a late stage in which, cancer cells would have already detached from the primary tumor to spread and invade other parts of the body.

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Objective: New therapeutic approaches are needed to improve the prognosis of glioblastoma (GBM) patients.

Methods: With the objective of identifying alternative oncogenic mechanisms to abnormally activated epidermal growth factor receptor (EGFR) signalling, one of the most common oncogenic mechanisms in GBM, we performed a comparative analysis of gene expression profiles in a series of 54 human GBM samples. We then conducted gain of function as well as genetic and pharmocological inhibition assays in GBM patient-derived cell lines to functionnally validate our finding.

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The canonical prolactin (PRL) Signal Transducer and Activator of Transcription (STAT) 5 pathway has been suggested to contribute to human prostate tumorigenesis via an autocrine/paracrine mechanism. The probasin (Pb)-PRL transgenic mouse models this mechanism by overexpressing PRL specifically in the prostate epithelium leading to strong STAT5 activation in luminal cells. These mice exhibit hypertrophic prostates harboring various pre-neoplastic lesions that aggravate with age and accumulation of castration-resistant stem/progenitor cells.

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WS 1541 is a phytopharmaceutical drug combination containing a lipophilic extract from fruits of (WS 1473) and an aqueous ethanolic extract from roots of (WS 1031). It is approved in several countries worldwide for the treatment of lower urinary tract syndrome (LUTS) linked to benign prostate hyperplasia (BPH). Clinical studies have demonstrated the efficacy of this unique combination in the treatment of BPH-related LUTS.

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Active surveillance (AS) is an attractive alternative to immediate treatment for men with low-risk prostate cancer. Thus, the identification of environmental factors that promote the progression of indolent disease towards aggressive stages is critical to optimize clinical management. Epidemiological studies suggest that calcium-rich diets contribute to an increased risk of developing prostate cancer and that vitamin D reduces this risk.

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Active surveillance has emerged as an alternative to immediate treatment for men with low-risk prostate cancer. Accordingly, identification of environmental factors that facilitate progression to more aggressive stages is critical for disease prevention. Although calcium-enriched diets have been speculated to increase prostate cancer risk, their impact on early-stage tumors remains unexplored.

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Article Synopsis
  • The study focused on 95 women with multiple breast fibroadenomas (MFAs) to investigate the potential role of germline variants of the prolactin receptor (PRLR) in breast tumor development.
  • Research included a second MFA cohort of 71 women, 496 control subjects, and 119 women with breast cancer, examining the prevalence of PRLR variants across these groups.
  • Findings showed no significant link between PRLR variants and increased risk of breast cancer or MFAs, though ongoing research may reveal complex interactions with oncogenic pathways.
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Epidemiological studies that have investigated whether dairy (mainly milk) diets are associated with prostate cancer risk have led to controversial conclusions. In addition, no existing study clearly evaluated the effects of dairy/milk diets on prostate tumor progression, which is clinically highly relevant in view of the millions of men presenting with prostate pathologies worldwide, including benign prostate hyperplasia (BPH) or high-grade prostatic intraepithelial neoplasia (HGPIN). We report here a unique interventional animal study to address this issue.

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Background: Permixon®, the hexanic lipidosterolic extract of saw palmetto Serenoa repens (LSESr), has shown properties that highlight its benefit in the management of benign prostate hyperplasia (BPH). To address its actual anti-inflammatory potency, we used a unique pro-inflammatory mouse model of prostate hyperplasia involving prostate-specific over-expression of prolactin transgene (Pb-Prl).

Methods: Six month-old Pb-Prl males were administered with Permixon® per os at the daily dose of 100 mg/kg for 28 days.

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Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established.

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Current androgen ablation therapies for prostate cancer are initially successful, but the frequent development of castration resistance urges the generation of alternative therapies and represents an important health concern. Prolactin/signal transducer and activator of transcription 5 (STAT5) signaling is emerging as a putative target for alternative treatment for prostate cancer. However, mechanistic data for its role in development or progression of prostate tumors are scarce.

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Transformed and tumoral cells share the characteristic of being able to proliferate even when external calcium concentration is very low. We have investigated whether Human Embryonic Kidney 293 cells, human hepatoma cell Huh-7 and HeLa cells were able to proliferate when kept 72h in complete culture medium without external calcium. Our data showed that cell proliferation rate was similar over a range of external calcium concentration (2μM to 1.

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Evidence for a role for calcium channel proteins in cell proliferation is numerous suggesting that calcium influx is essential in this physiological process. Several studies in the past thirty years have demonstrated that calcium channel expression levels are determinant in cell proliferation. Voltage-gated, store-operated, second messengers and receptor-operated calcium channels have been associated to cell proliferation.

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Human scalp skin and hair follicles (HFs) are extra-pituitary sources of prolactin (PRL). However, the intracutaneous regulation of PRL remains poorly understood. Therefore we investigated whether well-recognized regulators of pituitary PRL expression, which also impact on human skin physiology and pathology, regulate expression of PRL and its receptor (PRLR) in situ.

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Transforming growth factor β (TGFβ) is widely recognised as an important factor that regulates many steps of normal mammary gland (MG) development, including branching morphogenesis, functional differentiation and involution. Tif1γ has previously been reported to temporally and spatially control TGFβ signalling during early vertebrate development by exerting negative effects over SMAD4 availability. To evaluate the contribution of Tif1 γ to MG development, we developed a Cre/LoxP system to specifically invalidate the Tif1g gene in mammary epithelial cells in vivo.

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