Production of nitric oxide (NO) by macrophages is important for the killing of intracellular infectious agents. Interferon (IFN)-gamma and lipopolysaccharide stimulate NO production by transcriptionally up-regulating the inducible NO synthase (iNOS). Macrophages from mice with a targeted disruption of the IFN regulatory factor-1 (IRF-1) gene (IRF-1-/- mice) produced little or no NO and synthesized barely detectable iNOS messenger RNA in response to stimulation. Two adjacent IRF-1 response elements were identified in the iNOS promoter. Infection with Mycobacterium bovis (BCG) was more severe in IRF-1-/- mice than in wild-type mice. Thus, IRF-1 is essential for iNOS activation in murine macrophages.

Carcinoma of the prostate is the most frequently diagnosed malignancy and the second leading cause of death as a result of cancer in men in the United States and in many other Western countries. Notwithstanding the importance of this malignancy, little is understood about its causes. The epidemiology of prostate cancer strongly suggests that environmental factors, particularly diet and nutrition, are major determinants of risk for this disease, and evidence is mounting that there are important genetic risk factors for prostate cancer. Human prostate carcinomas are often androgen sensitive and react to hormonal therapy by temporary remission, followed by relapse to an androgen-insensitive state. These well-established features of prostate cancer strongly suggest that steroid hormones, particularly androgens, play a major role in human prostatic carcinogenesis, but the precise mechanisms by which androgens affect this process are unknown. In addition, the possible involvement of estrogenic hormones is not entirely clear. The purpose of this overview is to summarize the literature about steroid hormonal factors, androgens and estrogens, and prostate carcinogenesis. From these literature observations, a multifactorial general hypothesis of prostate carcinogenesis emerges with androgens as strong tumor promoters acting via androgen receptor-mediated mechanisms to enhance the carcinogenic activity of strong endogenous genotoxic carcinogens, such as reactive estrogen metabolites and estrogen-and prostatitisgenerated reactive oxygen species and possible weak environmental carcinogens of unknown nature. In this hypothesis, all of these processes are modulated by a variety of environmental factors such as diet and by genetic determinants such as hereditary susceptibility and polymorphic genes that encode for steroid hormone receptors and enzymes involved in the metabolism and action of steroid hormones. [

SummaryMice with a targeted disruption of the interferon 7 receptor gene (IFN-TK ~176 mice) and control wild-type mice were inoculated with the Bacillus Calmette-Gu6rin (BCG) strain of Mycobacteriura boris. BCG infection was not lethal for wild-type mice whereas all IFN-7 K~176 mice died ,07-9 wk after inoculation. Histological examination at 2 and 6 wk after BCG inoculation showed that livers of IFN-TK ~176 mice had higher numbers of acid-fast bacteria than wild-type mice, especially at 6 wk. In parallel, the livers of IFN-TR ~176 mice showed a reduction in the formation of characteristic granulomas at 2 wk after inoculation. Injection of lipopolysaccharide (LPS) 2 wk after BCG inoculation was significantly less lethal for IFN-TK ~176 mice than for wild-type mice. Reduced lethality of LPS correlated with a drastically reduced production of tumor necrosis factor c~ (TNF-cr in the IFN-TR ~176 mice. Interleukin lot (IL-lot) and IL-6 levels in the serum were also significantly reduced in the IFN-7 K~176 mice after BCG infection and LPS challenge. The greatly reduced capacity of BCG-infected IFN-TK ~176 mice to produce TNF-ot may be an important factor in their inability to resist BCG infection. These results show that the presence of a functional IFN-7 receptor is essential for the recovery of mice from BCG infection, and that IFN-7 is a key element in the complex process whereby BCG infection leads to the sensitization to endotoxin.

This study determined the incidence of prostate adenocarcinoma following long-term treatment of NBL and Sprague-Dawley rats with estradiol-17 beta or diethylstilbestrol (DES) plus testosterone and it defined the origin of these tumors. NBL and Sprague-Dawley rats were treated with two Silastic tubing implants (i.d. 1.6 mm, o.d. 3.2 mm) containing a 2 cm long filling of testosterone and one implant containing a 1 cm long filling of estradiol-17 beta or DES. Control animals received empty implants. Treated animals were killed when moribund and controls were killed at 91 (NBL) or 75 (Sprague-Dawley) weeks after initiation of treatment and accessory sex glands were sampled for histopathological examination of multiple step sections. Prostatic adenocarcinoma occurred in 100% of NBL rats after treatment with estradiol-17 beta or DES plus testosterone for 44 and 59 weeks (group means) respectively. Adenocarcinoma incidences were lower in Sprague-Dawley rats. The adenocarcinomas were small, microscopic, invasive tumors and they were spatially closely associated with the periurethral ducts of the dorsal, lateral and/or anterior (= coagulating gland) prostate, but never with the ducts of the ventral lobe and seminal vesicles. One adenocarcinoma was of uncertain origin. Duct-acinar dysplastic lesions occurred in the periphery of the dorsal and lateral prostate of all hormone-treated NBL and many Sprague-Dawley rats, but did not appear to give rise to carcinoma. Although some adenocarcinomas were contiguous with dysplastic ducts of the peripheral dorsolateral prostate, the main mass of these neoplasms was located in the periurethral area. Also, most adenocarcinomas were only connected with the periurethral ducts, in which atypical hyperplasia occurred following hormone treatment for 36 weeks or longer. Thus atypical hyperplasia of the periurethral prostate ducts, but not peripheral duct-acinar dysplasia, appeared to be the likely precursor of the induced carcinomas. Testosterone plus DES, but not estradiol-17 beta, induced marked dysplasia-like lesions in the acini of the ventral prostate of all NBL and many Sprague-Dawley rats. These lesions had progressed to carcinoma in situ (or adenoma) in 46% of NBL rats.

Soy isoflavones are dietary components for which an association has been demonstrated with reduced risk of prostate cancer (PCa) in Asian populations. However, the exact mechanism by which these isoflavones may prevent the development or progression of PCa is not completely understood. There are a growing number of animal and in vitro studies that have attempted to elucidate these mechanisms. The predominant and most biologically active isoflavones in soy products, genistein, daidzein, equol, and glycetin, inhibit prostate carcinogenesis in some animal models. Cell-based studies show that soy isoflavones regulate genes that control cell cycle and apoptosis. In this review, we discuss the literature relevant to the molecular events that may account for the benefit of soy isoflavones in PCa prevention or treatment. These reports show that although soy isoflavone-induced growth arrest and apoptosis of PCa cells are plausible mechanisms, other chemo protective mechanisms are also worthy of consideration. These possible mechanisms include antioxidant defense, DNA repair, inhibition of angiogenesis and metastasis, potentiation of radio- and chemotherapeutic agents, and antagonism of estrogen- and androgen-mediated signaling pathways. Moreover, other cells in the cancer milieu, such as the fibroblastic stromal cells, endothelial cells, and immune cells, may be targeted by soy isoflavones, which may contribute to soy-mediated prostate cancer prevention. In this review, these mechanisms are discussed along with considerations about the doses and the preclinical models that have been used.

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Breast cancer (BC) patients use alternative and natural remedies more than patients with other malignancies. Specifically, 63%–83% use at least one type of alternative medicine and 25%–63% use herbals and vitamins. Propolis is a naturopathic honeybee product, and CAPE (caffeic acid phenethyl ester), is a major medicinal component of propolis. CAPE, in a concentration dependent fashion, inhibits MCF-7 (hormone receptor positive, HR+) and MDA-231 (a model of triple-negative BC (TNBC) tumor growth, both in vitro and in vivo without much effect on normal mammary cells and strongly influences gene and protein expression. It induces cell cycle arrest, apoptosis and reduces expression of growth and transcription factors, including NF-κB. Notably, CAPE down-regulates mdr-1 gene, considered responsible for the resistance of cancer cells to chemotherapeutic agents. Further, CAPE dose-dependently suppresses VEGF formation by MDA-231 cells and formation of capillary-like tubes by endothelial cells, implicating inhibitory effects on angiogenesis. In conclusion, our results strongly suggest that CAPE inhibits MDA-231 and MCF-7 human breast cancer growth via its apoptotic effects, and modulation of NF-κB, the cell cycle, and angiogenesis.

Background Soy isoflavone consumption may protect against breast cancer development. We conducted a Phase IIB trial of soy isoflavone supplementation, to examine its effect on breast epithelial proliferation and other biomarkers in the healthy high risk breast. Methods 126 consented women underwent a random fine needle aspiration (rFNA); those with ≥ 4000 epithelial cells were randomized to a double-blind six-month intervention of mixed soy isoflavones (PTIG-2535) or placebo, followed by repeat rFNA. Cells were examined for Ki-67 labeling index (Ki-67 LI), and atypia. Expression of 28 genes related to proliferation, apoptosis and estrogenic effect was measured using quantitative RT-PCR. Hormone and protein levels were measured in nipple aspirate fluid (NAF). All statistical tests were 2-sided. Results 98 women were evaluable for Ki-67 LI. In 49 treated women, the median Ki-67 LI was 1.18 at entry and 1.12 post-intervention, whereas in 49 placebo subjects it was 0.97 and 0.92 (p for between-group change 0.32). Menopausal stratification yielded similar results between groups, but within premenopausal soy-treated women, Ki-67 LI increased from 1.71 to 2.18 (p=0.04). We saw no treatment effect on cytologic atypia or NAF parameters. There were significant increases in the expression of 14/28 genes within the soy, but not the control group, without significant between-group differences. Plasma genistein values demonstrated excellent compliance. Conclusions A six-month intervention of mixed soy isoflavones in healthy, high risk adult western women did not reduce breast epithelial proliferation, suggesting a lack of efficacy for breast cancer prevention, and a possible adverse effect in premenopausal women.