Observing the Changes of Fibroblast Growth Factor 23 in Patients of Tumor Induced Osteomalacia
|ClinicalTrials.gov Identifier: NCT01660308|
Recruitment Status : Recruiting
First Posted : August 8, 2012
Last Update Posted : July 6, 2016
Fibroblast froth factors (FGFs) are humoral factors identified by their ability to stimulate cell proliferation1. They play different roles in the regulation of cell proliferation, differentiation and function. Most FGF family members act as paracrine factors. But FGF19(FGF19) subfamily members, including FGF19, 21, and 23, work as endocrine factors to regulate bile acid, carbohydrate and phosphate metabolism2. Of these, FGF23 plays an important role in phosphate and bone metabolism3. FGF23 gene encodes 251 amino acids, including a 24-amino acid signal peptide4. The secreted FGF23 is a protein consisted of 227 amino acids. It works by binding to a Klotho-FGF receptor 1c (FGF1c) complex5. FGF suppresses the expression of type 2a and 2c sodium-phosphate cotransporters, which mediate phosphate reabsorption in proximal tubules.6 FGF23 decreases 25-hydroxyvitamin D-1α-hydroxylase expression and enhances 25-hydroxyvitamin D-24-hydroxylase expression6. Therefore, FGF23 reduces serum 1,25-dihydroxyvitamin D〔1,25(OH)2D〕, which stimulates intestinal calcium and phosphate absorption. FGF23 decreases serum phosphate through the above mechanisms FGF23 over-expression might result in hypophosphatemic rickets and osteomalacia.
Tumor induced osteomalacia (TIO) is a paraneoplastic syndrome usually caused by benign phosphaturic mesenchymal tumors. Symptoms are nonspecific, such as general weakness, fatigue, and bone pain. Sometimes fracture may occurs. The responsible tumors are sometimes small and difficult to detect. Tumors secrete FGF23. FGF23 reduced phosphate reabsorption in the proximal tubules and decrease 1,25(OH)2D levels, which result in hypophosphatemia and then osteomalacia.
The investigators would like to observe the changes of FGF23 in patients who receive operation or medical treatment and hope this will benefit future treatment.
|Condition or disease|
|Study Type :||Observational|
|Estimated Enrollment :||40 participants|
|Observational Model:||Case Control|
|Official Title:||Observing the Changes of Fibroblast Growth Factor 23 in Patients of Tumor Induced Osteomalacia|
|Study Start Date :||June 2011|
|Estimated Primary Completion Date :||August 2016|
|Estimated Study Completion Date :||August 2016|
|Tumor induced osteomalcia|
- FGF23, P [ Time Frame: at the time TIO is diagnosed ]
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01660308
|Contact: Shyang-Rong Shih, PhDemail@example.com|
|National Taiwan University Hospital||Recruiting|
|Contact: Shyang-Rong Shih, PhD 886-972653337 firstname.lastname@example.org|
|Principal Investigator: Shyang-Rong Shih, PhD|
|Principal Investigator:||Shyang-Rong Shih, PhD||National Taiwan University Hospital|