We have characterized the production of transforming growth factor (TGF) activities by five human breast cancer cell lines in culture. The presence of TGF-α and -β activity in medium conditioned by these cells was detected by induction of anchorage-independent colony formation of normal rat kidney cells in soft agar and by epidermal growth factor and TGF-β receptor competition studies. In MCF-7, an estrogen-receptor positive cell line which requires estrogen for tumorigenesis in vivo, 17(β)-estradiol induced a 2-5 fold increase in a TGF-α-like activity (apparent molecular weight, 68,000 and 30,000 by column chromatography). An estrogen induction of lower magnitude (1.5-2.5-fold) was also seen in two other estrogen responsive cell lines, ZR-75-B and T47D. TGF-β was not induced by 17(β)-estradiol in any of the three cell lines and was decreased by up to 50% of control in the MCF-7 and T47D cell lines. TGF-β was not detectable by radioreceptor assay in the ZR-75-B cell line. Two hormone-independent and highly tumorigenic cell lines were studied. The MDA-MB-231 cell line produced large amounts of both TGF-α-like (M(r) 30,000) and TGF-β activities. In the HS578T cell line, little TGF-α was detectable, while large amounts of TGF-β were produced. No simple correlations between the tumorigenicity of the cell lines in nude mice and production of either TGF activity could be demonstrated.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Apr 1 1986|
ASJC Scopus subject areas
- Cancer Research