DIFFERENTIAL GROWTH-RESPONSE TO ESTROGEN OF PREMALIGNANT AND MALIGNANT COLONIC CELL-LINES

Epidemiological and experimental evidence support a role for sex stero id hormones in colorectal cancer. The aims of this study were to deter mine expression of oestrogen receptor in adenoma derived and carcinoma derived colonic epithelial cell lines, and to determine the in vitro effect of beta oestradiol on growth. Between 0.5-1.5 fmol/mg protein o f oestrogen receptor was expressed in the colonic cell lines studied, mRNA for oestrogen receptor was also expressed. An adenoma derived cel l line, AA/C1, demonstrated an ina ease in growth rate in response to beta oestradiol. The effect was density dependent. The cell line AA/C1 /SB10, a chemically transformed derivative of AA/C1, did not respond t o beta oestradiol. Adenoma derived and carcinoma derived colonic cell lines express oestrogen receptor. Oestrogen may have a trophic action in vivo or premalignant colonic epithelium.