Bone morphogenetic proteins are expressed by both bone-forming and non-bone-forming lesions.
BACKGROUND
Bone morphogenetic proteins (BMPs) are thought to be responsible for bone formation; they cause bone to form in soft tissues and are clinically used in helping fracture union or tumor reconstructions. Skeletal metastases from epithelial tumors may be either bone-forming (blastic) or non-bone-forming (lytic).


OBJECTIVE
We studied the expression of BMPs in a variety of primary and secondary lesions of bone (both bone-forming and non-bone-forming) to determine if there was a consistent relationship between bone formation and BMP expression.


METHODS
We compared a bone-forming lesion (fibrous dysplasia) with a non-bone-forming lesion (desmoid tumor), using reverse transcription-polymerase chain reaction, Northern blot analysis, and immunohistochemistry to detect BMPs. We also studied a number of non-bone-forming secondary lesions (carcinomas that formed lytic metastases to the skeleton) and found BMP production in most of these tumors.


RESULTS
We found that BMPs were expressed in both bone-forming and non-bone-forming benign musculoskeletal lesions. In the first part of the study, BMPs were found in both fibrous dysplasia and desmoid tumors. Bone morphogenetic proteins were also expressed by several tumors. In the next part of the study (paraffin-embedded tissue), BMPs were expressed by a variety of tumors, irrespective of the radiological nature (blastic or lytic) of their metastases.


CONCLUSIONS
We conclude that BMP production alone cannot explain bone formation, and other factors either alone or in combination may be responsible for blastic metastases to the skeleton and for bone formation by primary bone lesions, such as fibrous dysplasia.
Khurana
Jasvir S
JS
Department of Pathology, Temple University Hospital, Philadelphia, Pa 19140, USA. khuranjs@tuhs.temple.edu
Ogino
Shuji
S
Shen
Ting
T
Parekh
Hemant
H
Scherbel
Uwe
U
DeLong
William
W
Feldman
Michael D
MD
Zhang
Paul J
PJ
Wolfe
Hubert J
HJ
Alman
Benjamin A
BA
D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D052005:Bone Morphogenetic Protein Receptors, Type I; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D001859:Bone Neoplasms / Q000235:genetics / Q000556:secondary; D002277:Carcinoma / Q000235:genetics / Q000556:secondary; D002460:Cell Line; D045744:Cell Line, Tumor; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D018222:Desmoid Tumors / Q000235:genetics*; D005358:Fibrous Dysplasia, Monostotic / Q000235:genetics*; D005359:Fibrous Dysplasia, Polyostotic / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D012516:Osteosarcoma / Q000235:genetics / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000276:immunology; D012313:RNA / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D017978:Receptors, Growth Factor / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
C525718:BMP2 protein, human; C525809:BMP4 protein, human; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D012334:RNA, Neoplasm; D017978:Receptors, Growth Factor; D016212:Transforming Growth Factor beta; D012313:RNA; D017346:Protein Serine-Threonine Kinases; D052005:Bone Morphogenetic Protein Receptors, Type I