Expression of stem cell factor and lack of c-kit expression in malignant fibrous histiocytoma of soft tissues.
BACKGROUND
Little information is available on the expression of stem cell factor (SCF) and its receptor c-kit in soft tissue tumors of a fibrohistiocytic origin, including malignant fibrous histiocytoma (MFH).


METHODS
We investigated the endogenous expression of SCF and c-kit in 43 MFH tissue samples using immunohistochemical techniques. Furthermore, we examined the correlation of SCF expression in MFHs with proliferative activity assessed by mitotic indices and MIB-1 immunohistochemical staining.


RESULTS
Positive immunoreactivity for c-kit was identified in tumor cells of only one MFH case, while the remaining 42 cases were negative. In the one positive case, immunohistochemical staining was focal. Positive immunoreactivity for SCF was identified in 31 out of 43 cases studied (72%, focal; 11, moderate; 6, diffuse; 14). There were no significant differences in the MIB-1 and mitotic indices between the SCF-positive and negative groups.


CONCLUSIONS
Our data indicate that any direct autocrine effects of the SCF/c-kit system on cell growth regulation are precluded in most MFH cases studied, but it is speculated that SCF might indirectly influence tumor growth by promoting local neovascularization.
Yamamoto
Tetsuji
T
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. yamatetu@med.kobe-u.ac.jp
Nakatani
Tetsuya
T
Marui
Takashi
T
Akisue
Toshihiro
T
Fujita
Ikuo
I
Matsumoto
Keiji
K
Hitora
Toshiaki
T
Kawamoto
Teruya
T
Nagira
Keiko
K
Kurosaka
Masahiro
M
D002455:Cell Division / Q000502:physiology; D018219:Histiocytoma, Benign Fibrous / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis* / Q000378:metabolism; D012983:Soft Tissue Neoplasms / Q000378:metabolism* / Q000473:pathology; D019089:Stem Cell Factor / Q000096:biosynthesis*
D019394:Ki-67 Antigen; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit