Parathyroid hormone-related protein (PTHrP) increases the growth and osteolytic potential of prostate cancer cells, making it important to control PTHrP expression. PTHrP expression is suppressed by 1,25-dihydroxyvitamin D(3) (1,25D). The aim of this study was to identify the pathways via which 1,25D exerts these effects. Our main findings are that 1,25D regulates PTHrP levels via multiple pathways in PC-3 and C4-2 (human prostate cancer) cell lines, and regulation is dependent on VDR expression. The human PTHrP gene has three promoters (P); PC-3 cells preferentially utilize P2 and P3, while C4-2 cells preferentially utilize P1. 1,25D regulates PTHrP transcriptional activity from both P1 and P3. The 1,25D-mediated decrease in PTHrP mRNA levels also involves a post-transcriptional pathway since 1,25D decreases PTHrP mRNA stability. 1,25D also suppresses PTHrP expression directly at the protein level by increasing its degradation. Regulation of PTHrP levels is dependent on VDR expression, as using siRNAs to deplete VDR expression negates the 1,25D-mediated downregulation of PTHrP expression. These results indicate the importance of maintaining adequate 1,25D levels and VDR status to control PTHrP levels.
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http://dx.doi.org/10.1016/j.mce.2011.05.025 | DOI Listing |
Diagn Pathol
January 2025
Department of Pathology, Faculty of Medicine, Menoufia University, Menoufia, Egypt.
Background: Globally, breast cancer ranks among the most common malignancies and has a high mortality rate. Invasive breast carcinoma of no special type (IBC-NST) presents a heterogeneous group with variable prognosis. Identifying reliable biomarkers is crucial for improving treatment strategies and predicting outcomes.
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December 2024
Departamento de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avda. de Atenas s/n, 28922 Alcorcón, Madrid, Spain.
Front Endocrinol (Lausanne)
December 2024
Rare Disease Research Group, Molecular (Epi) Genetics Laboratory, Bioaraba Health Research Institute, Araba University Hospital, Vitoria-Gasteiz, Spain.
Objective: To identify the genetic cause underlying the methylation defect in a patient with clinical suspicion of PHP1B/iPPSD3.
Design: Imprinting is an epigenetic mechanism that allows the regulation of gene expression. The locus is one of the loci within the genome that is imprinted.
Cell Biosci
December 2024
USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, USA.
Mammalian reproduction requires that nursing mothers transfer large amounts of calcium to their offspring through milk. Meeting this demand requires the activation of a brain-breast-bone circuit during lactation that coordinates changes in systemic hormones, dietary calcium intake, skeletal turnover, and calcium transport into milk. Classically, increased bone resorption via increased parathyroid hormone-related protein and low estrogen levels is the main source of calcium for milk production during lactation.
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December 2024
Department of Oral Anatomy and Physiology and TMD, College of Stomatology, the Fourth Military Medical University, Xi'an, China; Department of Oral Anatomy and Physiology and TMD, Shanghai Stomatological Hospital & School of Stomatology, Fudan University, Shanghai, China. Electronic address:
Objective: Some cells in temporomandibular joint (TMJ) cartilage undergo proliferation in response to negative pressure, which can be induced in vivo by creating bilateral anterior elevation (BAE). TMJ cartilage harbours CD90-expressing cells, and CD90 expression increases under certain controlled conditions. The parathyroid hormone-related peptide (PTHrP) nuclear localisation segment (NLS) promotes chondrocyte proliferation, and mammalian target of rapamycin (mTOR) signalling plays a regulatory role in promoting PTHrP transcription.
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