The role of growth factors, steroid hormones and their receptors in the proliferation of human prostate tumor cells, LNCaP

This thesis deals with a tumor cell line, named LNCaP, which has been derived from a lymph node carcinoma of the human prostate. LNCaP cells show androgen responsive growth. The first aim was to study the possible involvement of growth factors and their receptors in the proliferation of the androgen responsive cell line (chapter 3 to 5). As described before, the prostate is a target organ for steroid hormones such as testosterone. As most of prostate cancers are androgen responsive, endocrine therapy, directed at androgen deprivation, may influence their growth. Androgen deprivation can be assessed by inhibiting the release of luteinizing hormone releasing hormone and/or luteinizing hormone which results in a decrease in testosterone serum levels. One of the ways this can be achieved is by estrogen therapy. Estrogens mimic testosterone in the feedback mechanism thus blocking secretion of luteinizing hormone releasing hormone and luteinizing hormone ahd thereby the production of testicular testosterone. Antiandrogens are substances that prevent androgens from expressing their activity (e.g~ growth induction) at target tissue by blocking androgenreceptor interaction. The second aim of the thesis was to compare the effects of androgens with other steroids and antiandrogens concerning growth regulation and other physiological processes in the androgen responsive prostate tumor cell LNCaP (chapter 6 and 7). Finally, we have considered possible effects on LNCaP cells of suramin, a polyanionic compound which has been described to counteract growth factor activity. The effect of suramin on androgen responsive and growth factor responsive growth of LNCaP cells was studied (chapter 8)