Extracts from tumors causing oncogenic osteomalacia inhibit phosphate uptake in opossum kidney cells
in Journal of EndocrinologySearch for other papers by KB Jonsson in
Current site
Google Scholar
PubMed
Search for other papers by M Mannstadt in
Current site
Google Scholar
PubMed
Search for other papers by A Miyauchi in
Current site
Google Scholar
PubMed
Search for other papers by IM Yang in
Current site
Google Scholar
PubMed
Search for other papers by G Stein in
Current site
Google Scholar
PubMed
Search for other papers by O Ljunggren in
Current site
Google Scholar
PubMed
Search for other papers by H Juppner in
Current site
Google Scholar
PubMed
In oncogenic osteomalacia (OOM), a tumor produces an unknown substance that inhibits phosphate reabsorption in the proximal tubules. This causes urinary phosphate wasting and, as a consequence, hypophosphatemic osteomalacia. To characterize this poorly understood biological tumor activity we generated aqueous extracts from several OOM tumors. Extracts from three of four tumors inhibited, dose- and time-dependently, (32)P-orthophosphate uptake by opossum kidney (OK) cells; maximum inhibition was about 45% of untreated control. Further characterization revealed that the factor is resistant to heat and several proteases, and that it has a low molecular weight. The tumor extracts also stimulated cAMP accumulation in OK cells, but not in osteoblastic ROS 17/2.8 and UMR106 cells, or in LLC-PK1 kidney cells expressing the parathyroid hormone (PTH)/PTH-related peptide receptor or the PTH-2 receptor. HPLC separation of low molecular weight fractions of the tumor extracts revealed that the flow-through of all three positive tumor extracts inhibited (32)P uptake and stimulated cAMP accumulation in OK cells. Additionally, a second peak with inhibitory activity on phosphate transport, but without cAMP stimulatory activity, was identified in the most potent tumor extract. We have concluded that several low molecular weight molecules with the ability to inhibit phosphate transport in OK cells can be found in extracts from OOM tumors. It remains uncertain, however, whether these are related to the long-sought phosphaturic factor responsible for the phosphate wasting seen in OOM patients.
Journal of Endocrinology is committed to supporting researchers in demonstrating the impact of their articles published in the journal.
The two types of article metrics we measure are (i) more traditional full-text views and pdf downloads, and (ii) Altmetric data, which shows the wider impact of articles in a range of non-traditional sources, such as social media.
More information is on the Reasons to publish page.
| Sept 2018 onwards | Past Year | Past 30 Days | |
|---|---|---|---|
| Full Text Views | 94 | 37 | 3 |
| PDF Downloads | 98 | 46 | 4 |
Online ISSN: 1479-6805
Print ISSN: 0022-0795
Strengthening biomedical communities
to advance science and health
CONTACT US
Bioscientifica Ltd | Starling House | 1600 Bristol Parkway North | Bristol BS34 8YU | UK
Bioscientifica Ltd | Registered in England no 3190519