ULTRASTRUCTURAL EVIDENCE FOR DIVERGENT AND ALTERNATING DIFFERENTIATIONS IN SPINDLE-CELL SARCOMA XENOGRAFTS

Citation
U. Schmidt et al., ULTRASTRUCTURAL EVIDENCE FOR DIVERGENT AND ALTERNATING DIFFERENTIATIONS IN SPINDLE-CELL SARCOMA XENOGRAFTS, Journal of submicroscopic cytology and pathology, 29(2), 1997, pp. 187-195
Citations number
34
Categorie Soggetti
Cell Biology",Pathology
ISSN journal
11229497
Volume
29
Issue
2
Year of publication
1997
Pages
187 - 195
Database
ISI
SICI code
1122-9497(1997)29:2<187:UEFDAA>2.0.ZU;2-B
Abstract
Seven spindle cell sarcomas, 5 poorly differentiated ones and 2 modera tely well differentiated ones, were established on nude mice and long term passaging was done. Sarcoma strains were analysed electron micros copically in an attempt to get further insight in spindle cell sarcoma differentiation pathways. Ultrastructurally, the tumours were classif ied as malignant peripheral nerve sheath tumour (3/7), leiomyosarcoma (2/7), rhabdomyosarcoma (1/7), and spindle cell sarcoma not otherwise classifiable (1/7). Undifferentiated tumour cells including fibroblast oid ones predominated in most xenografts, whereas cells harbouring cyt oplasmic specificities tended to be few in number. Nevertheless, diver gent differentiations exhibiting unusual double or triple patterns cou ld be documented ultrastructurally in 12/30 xenografts with juxtaposed myomatous as well as nerve sheath-like cells and, in addition, histio cytoid (MFH-like) elements in 3 of the xenografts. Moreover, sarcoma s trains alternated fine structural constellations in the course of pass aging, whereby different phenotypes, myomatous, nerve sheath-like, uns pecific, or mixed ones, succeeded one another. These findings pursue r ecent immunohistochemical data on multidirectional sarcoma differentia tion by means of electron microscopy. They, furthermore, fit well into the concept of multipotential stem cells as progenitors in mesenchyma l differentiation and suggest microenvironment to play a modifying rol e in the expression of cell differentiation.