High levels of cellular retinol binding protein-1 expression in leiomyosarcoma: possible implications for diagnostic evaluation.
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.
Institute of Anatomic Pathology, Tor Vergata University of Rome, Italy.
Augusto
A
Orlandi
Arianna
A
Francesconi
Sophie
S
Clément
Patricia
P
Ropraz
Luigi Giusto
LG
Spagnoli
Giulio
G
Gabbiani
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000145:classification / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D007890:Leiomyosarcoma / Q000145:classification / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D012177:Retinol-Binding Proteins / Q000096:biosynthesis*; D054840:Retinol-Binding Proteins, Cellular; D014594:Uterine Neoplasms / Q000145:classification / Q000175:diagnosis / Q000378:metabolism*
D014408:Biomarkers, Tumor; C518456:RBP1 protein, human; D012177:Retinol-Binding Proteins; D054840:Retinol-Binding Proteins, Cellular