Matrix extracellular phosphoglycoprotein is expressed in causative tumors of oncogenic osteomalacia.

Abstract

Oncogenic osteomalacia (OOM), or tumor-induced osteomalacia, is a rare disease characterized by renal phosphate wasting and osteomalacia. It arises due to the secretion of fibroblast growth factor 23 (FGF-23) from causative tumors. Matrix extracellular phosphoglycoprotein (MEPE) is predominantly expressed in odontoblasts, osteoblasts, and osteocytes. Although the presence of MEPE mRNA has been reported in some OOM tumors, little is known about the prevalence of MEPE expression in OOM tumors. In this study, the expression of MEPE and FGF-23 in OOM tumors was investigated at the transcriptional and translational levels. Eleven causative OOM tumors were analyzed by quantitative real-time reverse transcription-polymerase chain reaction and immunohistochemistry for MEPE and FGF-23 expression. Hemangiopericytomas and giant cell tumors, pathological diagnoses that are common in cases of OOM, were obtained from non-osteomalacic patients and analyzed as controls. The gene expression level of FGF23 and MEPE in OOM tumors was 10(4)- and 10(5)-times higher, respectively, than in non-OOM tumors. Immunohistochemical staining revealed that FGF-23 protein was expressed in all OOM tumors, and MEPE was expressed in 10 out of 11 OOM tumors. Thus, MEPE expression was common in OOM tumors, similar to FGF-23. These results indicate that, in addition to the hypophosphatemic effects of FGF-23, MEPE or the MEPE-derived acidic serine aspartate-rich MEPE-associated motif peptide may contribute to decreased bone mineralization in OOM patients.

• Authors: Yasuo Imanishi, Jun Hashimoto, Wataru Ando, Keisuke Kobayashi, Takafumi Ueda, Yuki Nagata, Akimitsu Miyauchi, Hajime M Koyano, Hiroshi Kaji, Takatoshi Saito, Koichi Oba, Yasato Komatsu, Tomoaki Morioka, Katsuhito Mori, Takami Miki, Masaaki Inaba
• Journal: Journal of bone and mineral metabolism (J Bone Miner Metab) Vol. 30 Issue 1 Pg. 93-9 (Jan 2012) ISSN: 1435-5604 [Electronic] Japan
• PMID: 21739089 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Extracellular Matrix Proteins
• FGF23 protein, human
• Glycoproteins
• MEPE protein, human
• Phosphoproteins
• Fibroblast Growth Factors
• Fibroblast Growth Factor-23

Topics

• Adult
• Aged
• Extracellular Matrix Proteins (genetics, metabolism)
• Female
• Fibroblast Growth Factor-23
• Fibroblast Growth Factors (genetics, metabolism)
• Gene Expression Regulation, Neoplastic
• Glycoproteins (genetics, metabolism)
• Humans
• Immunohistochemistry
• Male
• Middle Aged
• Neoplasms, Connective Tissue (genetics, metabolism, pathology)
• Osteomalacia
• Paraneoplastic Syndromes
• Phosphoproteins (genetics, metabolism)
• Young Adult