scholarly journals Calcium stimulates parathyroid hormone-related protein production in Leydig tumor cells through a putative cation-sensing mechanism

2000 ◽  
pp. 500-505 ◽  
Author(s):  
N Buchs ◽  
D Manen ◽  
JP Bonjour ◽  
R Rizzoli
Keyword(s):  
Parathyroid Hormone ◽  
Cell Membrane ◽  
Tumor Cells ◽  
Dependent Manner ◽  
Related Protein ◽  
Sensing Mechanism ◽  
Calcium Sensing ◽  
Parathyroid Hormone Related Protein ◽  
Leydig Tumor Cells ◽  
Cation Sensing

The production of parathyroid hormone-related protein (PTHrP) is regulated by a variety of hormones and growth factors. Previous research has shown that several PTHrP-producing cells are influenced by extracellular calcium (Ca(2+)(o)) concentration, with elevated levels increasing PTH-like activity released by cultured H500 rat Leydig tumor cells through a post-transcriptional mechanism. We have investigated the hypothesis that calcium stimulates PTHrP production in H500 cells by interacting with a cell membrane-associated cation-sensing receptor. Besides increased Ca(2+)(o) concentration, magnesium and the polycationic antibiotic neomycin also increased PTHrP production in a concentration-dependent manner. In the presence of the calcium ionophore, ionomycin, which markedly elevated cytosolic free calcium, the stimulation by Ca(2+)(o) of PTHrP could still be detected. These results indicate that increasing Ca(2+)(o) stimulates PTHrP production, possibly through a putative cell membrane-associated calcium-sensing mechanism. RT-PCR revealed the presence of a very small amount of calcium-sensing receptor coding mRNA.

Small Cell Carcinoma of the Ovary With Hypercalcemia and Ectopic Parathyroid Hormone Production

2005 ◽  
Vol 129 (4) ◽  
pp. 531-533 ◽  
Author(s):  
Lei Chen ◽  
Tri A. Dinh ◽  
Abida Haque
Keyword(s):  
Parathyroid Hormone ◽  
Cell Carcinoma ◽  
Tumor Cells ◽  
Small Cell Carcinoma ◽  
Small Cell ◽  
Related Protein ◽  
Hormone Production ◽  
Parathyroid Hormone Related Protein ◽  
Ectopic Parathyroid ◽  
Carcinoma Of The Ovary

Abstract Small cell carcinoma of the ovary is a rare malignant tumor of the ovary. It is the most common undifferentiated ovarian carcinoma in young women. Approximately two thirds of patients with ovarian small cell carcinoma have hypercalcemia. The mechanism of development of hypercalcemia is unclear, although parathyroid hormone–related protein has been found in some of the cases. Parathormone expression in tumor cells, rarely reported, was seen in this case, suggesting that ectopic parathyroid hormone production by the tumor cells may be the cause of hypercalcemia.

Effects of parathyroid hormone-related protein on human mesangial cells in culture

1999 ◽  
Vol 277 (6) ◽  
pp. E990-E995 ◽  
Author(s):  
Ricardo J. Bosch ◽  
Pilar Rojo-Linares ◽  
Guadalupe Torrecillas-Casamayor ◽  
M. Carmen Iglesias-Cruz ◽  
Diego Rodríguez-Puyol ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Mesangial Cells ◽  
Biological Effects ◽  
Human Kidney ◽  
Kidney Cortex ◽  
Dependent Manner ◽  
Related Protein ◽  
Human Mesangial Cells ◽  
Parathyroid Hormone Related Protein ◽  
Pthrp Receptor

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) produce similar biological effects through the PTH/PTHrP receptor. Because PTHrP exhibits vasodilatory properties, we evaluated the hypothesis that this hormone interacts with human mesangial cells (HMC). The PTHrP prevented both the expected reduction in the planar cell surface area and the increase in myosin light-chain phosphorylation induced by platelet-activating factor (PAF) on HMC, in a dose-dependent manner. This effect was completely blocked by pertussis toxin and dideoxyadenosine, suggesting that a G protein-coupled receptor and cAMP are important in the PTHrP transduction mechanism. Moreover, PTHrP increased cAMP synthesis and thymidine incorporation in HMC. However, whereas RT-PCR and Southern and Northern blot analyses demonstrated the expression of human PTH/PTHrP receptor in human kidney cortex, no expression could be demonstrated in HMC. These results show that PTH and PTHrP directly interact with mesangial cells. These effects might be mediated by a receptor different from the PTH/PTHrP receptor.

scholarly journals The calcium-sensing receptor and parathyroid hormone-related protein are expressed in differentiated, favorable neuroblastic tumors

Cancer ◽  
2009 ◽  
Vol 115 (12) ◽  
pp. 2792-2803 ◽  
Author(s):  
Carmen de Torres ◽  
Helena Beleta ◽  
Rubén Díaz ◽  
Núria Toran ◽  
Eva Rodríguez ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Related Protein ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing ◽  
Parathyroid Hormone Related Protein ◽  
Neuroblastic Tumors
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