Autocrine and paracrine growth regulation of human breast cancer

Variation of hormonal receptor, pS2, c-erbB-2 and GSTπ contents in breast carcinomas under tamoxifen: a study of 74 cases

“…They also downregulate oestrogen-stimulated secretion of several specific proteins (Horwitz et al, 1978;Kida et al, 1989;Daly and Darbre, 1990;Chalbos et al, 1993;Warri et al, 1993). Some of these effects are reversible by oestradiol (Lippman et al, 1986;Gottardis et al, 1988;Daly and Darbre, 1990). A recent report has suggested that the growth-inhibitory effects of tamoxifen may be explained in part by its ability to disrupt a complex between ER, ERAP160 (an ER-associated protein supposed to mediate oestradiol dependent transcriptional activation) and other factors necessary for transactivation (Halachmi et al, 1994).…”

“…Human breast cancer cells also secrete growth factors. In hormone-dependent cells, several are oestrogen-regulated, whereas in cells which acquire independence they are constitutively increased (Lippman et al, 1986). Furthermore, the antioestrogenic properties and the antigrowth factor effects of antioestrogens can be dissociated, thus indicating that the latter is not a direct consequence of the former (Chalbos et al, 1993).…”

“…For instance, these modifications were an increase in pS2 mRNA level while the PR level was variable. Under tamoxifen therapy, an increase in the expression of some growth factors has also al., 1986;Daly and Darbre, 1990). The pS2 protein is suspected to have a growth factor function (Rio et al, 1988;Jakowlew et al, 1984).…”

Stromal influences on breast cancer cell growth

“…Various growth factors influence the growth of human breast cancer cells in vitro (Lippman et al, 1986a;Lippman et al, 1987). It has been suggested that both autocrine and paracrine mechanisms may play a role in vivo (Lippman et al, 1986a;Lippman et al, 1987;Osborne & Arteaga, 1990a).…”

Co-stimulation of gastrointestinal tumour cell growth by gastrin, transforming growth factor α and insulin like growth factor-I

“…Earlier studies have shown that drugs which alter gastrin secretion Watson et al, 1989d) or block gastrin binding Watson et al, 1989aJ) can inhibit growth of human gastrointestinal tumours growing in nude mice. Whether these drugs or new drugs can act like the anti-oestrogen drug, tamoxifen, (Lippman et al, 1986;Wakeling et al, 1989) and also prevent growth factor secretion remains to be examined. In this context it is interesting that both TGFa and IGF-I have been suggested as autocrine growth factors for gastrointestinal cancers.…”