# CHARACTERIZATION OF A HUMAN OSTEOCLAST-LIKE CELL LINE

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCIENCE CENTER · 1987 · $92,540

## Abstract

Much information has been learned about the osteoblast through the use of
several cloned osteosarcoma cell lines which have the osteoblast phenotype
and have provided convenient models of osteoblast behavior and function.
No such cell line has been available as a model for the osteoclast.  In
part, this may be because the mature osteoclast is a terminal cell which
does not proliferate.  I have cloned a novel non-tumor forming cell line
(FM-2) with osteolytic properties from a human osteosarcoma.  Phenotypic
characterization of this cell line as expressed in their ultrastructure,
enzyme contents, multinucleation, calcitonin receptors (see Appendix)
suggests that it is either an osteoclast precursor or a unique bone
resorbing cell.  The formation of spleen colony forming units when infused
into irradiated rats and the phenotypic modulations shown by this cell when
grown on three-dimensional collagen lattices further suggest that it may be
an osteoclast "stem cell".  The overall objective of this research proposal
is to determine if it is a cell in the osteoclast lineage, to further
characterize the osteoclastic properties of the FM-2 cell line and to
define the conditions which permit maximal expression of these
osteoclast-like properties.

The experimental protocol is designed to:  1) identify and optimize the
culture and substrate conditions which are critical for differentiation of
the FM-2 cell line.  This will be achieved by culturing the cells on
devitalized bone or reconstituted substrates which may resemble bone or in
an isolated in vivo system, the atriocular space of nude mice.  A
morphologic and biochemical profile to monitor phenotypic changes in the
line or new sublines will be developed, 2) determine the effects of
hormones active in bone (e.g., parathyroid hormone, calcitonin, or
1,25(OH)2D3) and differentiation factors (e.g., colony stimulating factor,
OAF, 5-azacytidine, retinoic acid) on the phenotypic expression of the cell
line, 3) restore bone remodeling function to microphthalmic mice by FM-2
cell grafts, 4) isolate and partially purify the bone resorbing factor
using hydroxyapatite chromatography.  The partially purified factor will be
used to generate monoclonal antibodies for subsequent use in affinity
chromatography and studies of the biological properties of the factor.

These studies should provide new information on the differentiation of bone
resorbing stem cells in vitro.  The establishment of differentiated bone
resorbing cells may prove useful as modes for understanding the biology and
biochemistry of osteoclasts and other bone resorbing cells.  Such models
could also be applied to investigations of the mechanisms of bone loss in
both physiologic and pathologic states.

## Key facts

- **NIH application ID:** 3157307
- **Project number:** 5R01AR035627-03
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
- **SAM.gov UEI:** C3KXNLTAAY98
- **Principal Investigator:** JAMES F DUNN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $92,540
- **Award type:** 5
- **Project period:** 1985-09-20 → 1988-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157307

## Citation

> US National Institutes of Health, RePORTER application 3157307, CHARACTERIZATION OF A HUMAN OSTEOCLAST-LIKE CELL LINE (5R01AR035627-03). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3157307. Licensed CC0.

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