Hormone dependent tumors stimulation

Steroids - Large doses of estrogen inhibit prolactin stimulation of mammary tumor growth as demonstrated by the effect of estradiol benzoate to DMBA-lnduced mammary adenocarcinomas in female rats. Estrogen may be involved in transport of RNA from nucleus to cytoplasm. Specific binding of estradiol within the nucleus is confined to hormone-dependent tumors... 

Alternative mRNA maturation is frequent in tumor tissue expressing ER. In some cases it would give rise to truncated receptors that would maintain the capacity to bind hormones but would have lost their capacity as a transcription factor. Additionally, truncated receptors would be produced that would lack the capacity to bind hormones but would conserve intact their capacity to interact with DNA. In this case, the truncated receptors can become tumorigenic by stimulating the proliferation of cells uncontrolled by hormones. These receptor variants have been the object of exhaustive study at the level of mRNA in tumors of the breast, mainly estrogen-dependent tumors (Clemons et al. 2001 Garcia et al. 1988 Palmieri et al. 2002), but tests for the existence of receptor protein with these characteristics have not corroborated the expectation created by their theoretical interest. 

My interest in the influence of diet on hormone-dependent cancers was first stimulated about 20 years ago by studies carried out in collaboration with colleagues at the Collip Medical Research Laboratory of the University of Western Ontario. They were involved in studies on the role of hormones in mammary cancer and for this purpose were inducing tumors in rats with 7,12-dimethylbenz(oi)-anthracene (DMBA) as described by Huggins et al ( 1). They were concerned to know whether hormonal treatment might affect tumorigenesis by altering the degree and time of exposure of mammary... 

Several cytokine receptors are present in prostate tumors and in prostate cancer cell lines. These include the granulocyte-macrophage colony-stimulating factor receptors (GM-CSF-R) and macrophage colony-stimulating factor receptor (M-CSF-R) (R7, RIO, S4). The presence of interleukin receptors in the prostate tumor which bind interleukins such as IL-2, IL-3, and IL-6 may play a role in hormone-dependent as well as in hormone-refractory prostate cancer tumors (Cl3, R6). However, the importance of these receptors needs to be illuminated. 

A dose-dependent decrease in trophoblast tumor cell proliferation was observed in estrogen receptor-positive Jeg3 cells treated with flaxseed extract or certain flaxseed extract fractions, with two fractions producing a 58 to 86% decrease in the production of progesterone. Some extract fractions showed a stimulating effect on hormone production and cell proliferation (Waldschlager et al. 2005). 

---