title: Effect of transforming growth factor-beta1, insulin-like growth factor-I and insulin-like growth factor-II on cell growth and oestrogen metabolism in human breast cancer cell lines.
abstract: Oestrogens play an important role in the development of breast cancer. Oestrone sulphate (E1S) acts as a huge reservoir of oestrogens in the breast and is converted to oestrone (E1) by oestrone sulphatase (E1STS). E1 is then reversibly converted to the potent oestrogen, oestradiol (E2) by oestradiol-17beta hydroxysteroid dehydrogenase (E2DH). The aim of this study was to assess the effects of transforming growth factor-beta1 (TGFbeta1), insulin-like growth factor-I (IGF-I) and insulin-like growth factor-II (IGF-II) on cell growth, E1STS and E2DH activities in the MCF-7 and MDA-MB-231 human breast cancer cell lines. TGFbeta1, IGF-I and IGF-II alone or in combination inhibited cell growth of both cell lines but no additive or synergistic effects were observed. The treatments significantly stimulated E1STS activity in the MCF-7 cell line, except for TGFbeta1 alone and TGFbeta1 and IGF-I in combination, where no effects were seen. Only TGFbeta1 and IGF-II acted synergistically to stimulate E1STS activity in the MCF-7 cells. There was no significant effect on E1STS activity in the MDA-MB-231 cells with any of the treatments. In the MCF-7 cells, TGFbeta1 and IGF-I, IGF-I and IGF-II, and TGFbeta1, IGF-I and IGF-II acted synergistically to stimulate the reductive E2DH activity, while only TGFbeta1, IGF-I and IGF-II synergistically stimulated the oxidative E2DH activity. There were no additive or synergistic effects on both oxidative and reductive E2DH activities in the MDA-MB-231 cells. In conclusion, TGFbeta1, IGF-I and IGF-II may have effects on oestrogen metabolism, especially in the MCF-7 cell line where they stimulated the conversion of E1S to E1 and E1 to E2 and, thus, may have roles to play in the development of breast cancer.
authors.affiliation: Department of Clinical Laboratory Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor.
authors.forename: S F
authors.initials: SF
authors.lastname: Wong
authors.forename: K
authors.initials: K
authors.lastname: Reimann
authors.forename: L C
authors.initials: LC
authors.lastname: Lai
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology / Q000473:pathology; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D004338:Drug Combinations; D004357:Drug Synergism; D004960:Estradiol Dehydrogenases / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology*; D013429:Sulfatases / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology
chemical_list: D004338:Drug Combinations; D004967:Estrogens; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D004960:Estradiol Dehydrogenases; D013429:Sulfatases; C020121:estrone sulfatase