Oestrone sulphate is a major source of active oestrogens in the breast. It is converted to oestrone by oestrone sulphatase. Breast cyst fluid (BCF) is a rich source of sex hormones and growth factors. BCF obtained from British women has been shown to inhibit oestrone sulphatase activity in the MCF-7 oestrogen-receptor-positive breast cancer cell line. The aim of the present study was to assess whether BCF obtained from Malaysian women inhibited oestrone sulphatase activity in the MCF-7 and MDA-MB-231 breast cancer cell lines. The cell lines were grown in supplemented Dulbecco's Modified Eagle Medium for 3 days, following which a 3-day incubation with sterilised BCF was carried out. At the end of the treatment period the cell monolayers were assayed for oestrone sulphatase activity and the number of cell nuclei counted on a Coulter Counter. BCF was also fractionated on a Bio-Sil SEC 125-5 column by HPLC and the effects of the fractions collected on oestrone sulphatase activity in the MDA-MB-231 cell line were assessed. All 18 samples of BCF tested inhibited cell growth in the MDA-MB-231 cell line while 8 out of 10 samples inhibited MCF-7 cell growth; 15 out of 18 BCF samples inhibited oestrone sulphatase activity in the MDA-MB-231 cell line whereas 5 out of 10 samples stimulated oestrone sulphatase activity in the MCF-7 cell line. HPLC fractions corresponding to molecular weights of > 158 kDa and 28 kDa were found to inhibit oestrone sulphatase activity in the MDA-MB-231 cell line. Further work is required to fully characterise these substances as they may have roles to play in the prevention of breast cancer.
Matched MeSH terms: Fibrocystic Breast Disease/metabolism*
We have analyzed unfractionated sera of newly diagnosed patients (n=10) with breast carcinoma (BC), prior to treatment, and patients (n=5) with fibrocystic disease of the breast (FDB) by two-dimensional gel electrophoresis (2-DE) and silver staining. The patients' 2-DE serum protein profiles obtained were then subjected to image analysis and compared to similar data generated from sera of normal healthy female controls (n=10) of the same range of age. The relative expression of alpha1-antichymotrypsin (ACT), clusterin, and complement factor B was significantly higher in all BC patients as compared to normal controls. However, the expression of alpha1-antitrypsin (AAT) in BC patients was apparently lower than that of the controls. Similar differential expression of ACT was detected in the FDB patients. The aberrant expression of the serum acute-phase proteins of patients with BC and FDB was confirmed by competitive enzyme-linked immunosorbent assay (ELISA). Similar altered proteins expression was also observed from immunohistochemical studies of malignant (n=5) and benign (n=5) breast lesions of the respective patients performed using antisera to the aberrantly expressed proteins. However, the malignant breast lesions were instead positively stained for AAT. The differential expression of the serum proteins was apparently abrogated when a six-month follow-up study was performed on nine of the BC patients subsequent to treatment.
Matched MeSH terms: Fibrocystic Breast Disease/metabolism*