Presence of immunoassayable transforming growth factor-beta 1 (TGF-beta 1) in breast cyst fluid (BCF): relationship with the intracystic electrolyte and epidermal-growth-factor (EGF) content.
We evaluated the presence and distribution of transforming growth factor-beta 1 (TGF-beta 1) in breast cyst fluid (BCF), and its relationship with intracystic epidermal growth factor (EGF). EGF and TGF-beta 1 were determined by radioimmunoassay on 47 BCFs (27 of the Na+/K+ < 3 type and 20 of the Na+/K+ > 3 type). As expected, EGF levels were inversely correlated with the Na+/K+ ratio, and were consequently higher in Na+/K+ < 3 cysts as compared with Na+/K+ > 3 cysts, (p < 0.005). By contrast, TGF-beta 1 levels were directly correlated with the Na+/K+ ratio (p < 0.01), being higher in Na+/K+ > 3 cysts, though not significantly (p = 0.057). A significant negative relationship was found between EGF and TGF-beta 1 concentration. When the analysis was performed separately in the 2 cyst sub-populations, EGF and TGF-beta 1 were found to be negatively and significantly correlated in Na+/K+ < 3 cysts only (p < 0.01). Our results demonstrate that Na+/K+ < 3 cysts contain high levels of EGF, a growth-stimulating factor, and very low levels of TGF-beta 1, a growth-inhibiting factor. This may provide an explanation for the higher risk of breast cancer observed in women with Na+/K+ < 3 cysts. Our results also suggest that EGF accumulation in this type of cysts might be regulated by TGF-beta 1.
Zanardi
S
S
Servizio di Oncologia Medica II, Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy.
Pensa
F
F
Torrisi
R
R
De Franchis
V
V
Barreca
A
A
Minuto
F
F
Boccardo
F
F
D004815:Epidermal Growth Factor / Q000032:analysis*; D005122:Exudates and Transudates / Q000737:chemistry*; D005260:Female; D005348:Fibrocystic Breast Disease / Q000737:chemistry*; D006801:Humans; D011188:Potassium / Q000032:analysis*; D012964:Sodium / Q000032:analysis*; D016212:Transforming Growth Factor beta / Q000032:analysis*
D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D012964:Sodium; D011188:Potassium