title: Expression of stem cell factor and lack of c-kit expression in malignant fibrous histiocytoma of soft tissues.
abstract: 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.
authors.affiliation: 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
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nakatani
authors.forename: Takashi
authors.initials: T
authors.lastname: Marui
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akisue
authors.forename: Ikuo
authors.initials: I
authors.lastname: Fujita
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hitora
authors.forename: Teruya
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Keiko
authors.initials: K
authors.lastname: Nagira
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
mesh_terms: 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*
chemical_list: D019394:Ki-67 Antigen; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit