High levels of cellular retinol binding protein-1 expression in leiomyosarcoma: possible implications for diagnostic evaluation

Virchows Arch. 2002 Jul;441(1):31-40. doi: 10.1007/s00428-001-0576-7. Epub 2002 Jan 31.


Retinoid bioavailability is regulated by the activity of specific cytoplasmic receptors. High levels of cellular retinol binding protein-1 (CRBP-1) have been documented during experimental arterial and wound-healing processes, but data concerning neoplastic smooth muscle tissues are scarce and/or controversial. This study reports that the expression of CRBP-1 is markedly higher in uterine and gastrointestinal leiomyosarcomas than in leiomyomas and normal myometrium; CRBP-1 was practically absent in normal gastrointestinal smooth muscle tissue. CRBP-1 positivity was particularly elevated in the epithelioid variant of leiomyosarcoma; it was associated with increased proliferative and apoptotic rates and inversely related to smooth muscle differentiation evaluated by alpha- and gamma-smooth muscle actin and desmin expression. Western blotting and reverse-transcription polymerase chain reaction confirmed the observations concerning CRBP-1 and actin isoform expression and revealed higher NF-kappa-Bp65 and RAR alpha and lower Bax protein levels in leiomyosarcoma than in the other conditions. These findings document that a high CRBP-1 expression is associated with smooth muscle malignancy and suggest that CRBP-1 expression represents a new useful marker for the classification of unusual variants of smooth muscle tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor*
  • Female
  • Gastrointestinal Neoplasms / classification
  • Gastrointestinal Neoplasms / diagnosis
  • Gastrointestinal Neoplasms / metabolism*
  • Humans
  • Leiomyosarcoma / classification
  • Leiomyosarcoma / diagnosis
  • Leiomyosarcoma / metabolism*
  • Male
  • Middle Aged
  • Muscle, Smooth, Vascular / metabolism
  • Muscle, Smooth, Vascular / pathology
  • Retinol-Binding Proteins / biosynthesis*
  • Retinol-Binding Proteins, Cellular
  • Uterine Neoplasms / classification
  • Uterine Neoplasms / diagnosis
  • Uterine Neoplasms / metabolism*


  • Biomarkers, Tumor
  • RBP1 protein, human
  • Retinol-Binding Proteins
  • Retinol-Binding Proteins, Cellular