Giuseppe Carruba

Estrogen and prostate cancer: an eclipsed truth in an androgen-dominated scenario.

Prostate cancer is the commonest non‐skin cancer in men. Incidence and mortality rates of this tumor vary strikingly throughout the world. Although several factors have been implicated to explain this remarkable variation, lifestyle and dietary factors may play a dominant role, with sex hormones behaving as intermediaries between exogenous factors and molecular targets in development and progression of prostate cancer. Human prostate cancer is generally considered a paradigm of androgen‐dependent tumor; however, estrogen role in both normal and malignant prostate appears to be equally important. The association between plasma androgens and prostate cancer remains contradictory and mostly not compatible with the androgen hypothesis. Similar evidence apply to estrogens, although the ratio of androgen to estrogen in plasma declines with age. Apart from methodological problems, a major issue is to what extent circulating hormones can be considered representative of their intraprostatic levels. Both nontumoral and malignant human prostate tissues and cells are endowed with key enzymes of steroid metabolism, including 17βhydroxysteroid dehydrogenase (17βHSD), 5β‐reductase, 3α/3βHSD, and aromatase. A divergent expression and/or activity of these enzymes may eventually lead to a differential prostate accumulation of steroid derivatives having distinct biological activities, as it occurs for hydroxylated estrogens in the human breast. Locally produced or metabolically transformed estrogens may differently affect proliferative activity of prostate cancer cells. Aberrant aromatase expression and activity has been reported in prostate tumor tissues and cells, implying that androgen aromatization to estrogens may play a role in prostate carcinogenesis or tumor progression. Interestingly, many genes encoding for steroid enzymes are polymorphic, although only a few studies have supported their relation with risk of prostate cancer. In animal model systems estrogens, combined with androgens, appear to be required for the malignant transformation of prostate epithelial cells. Although the mechanisms underlying the hormonal induction of prostate cancer in experimental animals remain uncertain, there is however evidence to support the assumption that long term administration of androgens and estrogens results in an estrogenic milieu in rat prostates and in the ensuing development of dysplasia and cancer. Both androgen and estrogen have been reported to stimulate proliferation of cultured prostate cancer cells, primarily through receptor‐mediated effects. As for estrogens, the two major receptor types, ERα and ERβ, are expressed in both normal and diseased human prostate, though with a different cellular localization. Since these two receptors are different in terms of ligand binding, heterodimerization, transactivation, and estrogen response element activity, it is likely that an imbalance of their expression may be critical to determine the ultimate estrogen effects on prostate cancer cells. In prostate cancer, ERβ activation appears to limit cell proliferation directly or through ERα inhibition, and loss of ERβ has been consistently associated with tumor progression. Several splicing variants of both ERα and ERβ exist. Little is known about their expression and function in the human prostate, although reciprocal regulation and interaction with gene promoter both warrant further investigation. In summary, although multiple consistent evidence suggests that estrogens are critical players in human prostate cancer, their role has been only recently reconsidered, being eclipsed for years by an androgen‐dominated interest. J. Cell. Biochem. 102: 899–911, 2007.

Inflammation, ageing and cancer

Cancer is generally recognized as an age-related disease. In fact, incidence and mortality rates of most human cancers increase consistently with age up to 90 years, but they plateau and decline thereafter. A low-grade systemic inflammation characterizes ageing and this pro-inflammatory status underlies biological mechanisms responsible for age-related inflammatory diseases. On the other hand, clinical and epidemiological studies show a strong association between chronic infection, inflammation and cancer and indicate that even in tumours not directly linked to pathogens, the microenvironment is characterized by the presence of a smouldering inflammation, fuelled primarily by stromal leukocytes. In this review, we have briefly mentioned inflammatory mediators involved in cancer although we decided to choose the ones which show a strict association with ageing and longevity. Inflammation is necessary to manage with damaging agents and is crucial for survival. But, in our opinion, the pro-inflammatory status of ageing might be one of the mechanisms which relate cancer to ageing. The most appropriate inflammatory genes have been selected to survive and to reproduce. Paradoxically, inflammatory age-related diseases (including cancer) are the marks of the same evolutionistic trait. Centenarians are characterized by a higher frequency of genetic markers associated with better control of inflammation. The reduced capacity of centenarians to mount inflammatory responses appears to exert a protective effect towards the development of those age-related pathologies having a strong inflammatory pathogenetic component, including cancer. All in all, centenarians seem to carry a genetic background with a peculiar resistance to cancer which is also an anti-inflammatory profile.

Inflammation and prostate cancer.

Prostate cancer remains a major health concern for the male population throughout the Western world. It is today widely accepted that inflammation has a role in many human cancers. In fact, inflammation is thought to incite carcinogenesis by causing cell and genome damage, promoting cellular turnover and creating a tissue microenvironment that can enhance cell replication, angiogenesis and tissue repair. Accordingly, there is a body of literature suggesting a link between chronic inflammation and prostate cancer, in which prostate inflammation may contribute to the promotion of prostate cancer development. On the other hand, high levels of endogenous gonadal steroids are considered as risk factors for prostate cancer. Interestingly, it is clear that elevation of estrogens in the presence of testosterone results in a prostate-specific inflammatory response. Thus, it is possible that early inflammatory events stimulated by sex hormones serve as a prerequisite for the onset of prostate cancer.

A Traditional Mediterranean Diet Decreases Endogenous Estrogens in Healthy Postmenopausal Women

Abstract: Breast cancer incidence and mortality rates are markedly lower in the south than in the north of Europe. This has been ascribed to differences in lifestyle and, notably, dietary habits across European countries. However, little information exists on the influence of different dietary regimens on estrogens and, hence, on breast cancer risk. Here we report results of our MeDiet Project, a randomized, dietary intervention study aimed to assess the effect of a Mediterranean diet on the profiles of endogenous estrogens in healthy postmenopausal women. Out of the 230 women who initially volunteered to participate in the study, 115 were found to be eligible and were enrolled. Women were then randomly assigned into an intervention (n = 58) and a control (n = 57) group. Women in the intervention group adhered to a traditional, restricted Mediterranean diet for 6 mo, whereas women in the control group continued to follow their regular diet. Women in the intervention group changed their dietary regimen substantially, and this eventually led to a shift from a prevalent intake of animal fat and proteins to a prevalent intake of vegetable fat and proteins. Regarding urinary estrogens, no significant difference was observed between the intervention and control groups at baseline. After 6 mo, however, control women did not show any major change but women in the intervention group exhibited a significant decrease (over 40%) of total estrogen levels (P < 0.02). The largest part of this modification was based on a marked decrease of specific estrogen metabolites, including hydroxyand keto-derivatives of estradiol or estrone. To our knowledge, this is the first report to show that a traditional Mediterranean diet significantly reduces endogenous estrogen. This may eventually lead to identify selected dietary components that more effectively decrease estrogens levels and, hence, provide a basis to develop dietary preventive measures for breast cancer.

Virokines in the pathogenesis of cancer: focus on human herpesvirus 8.

Abstract: During evolution, DNA viruses have captured a broad array of cellular genes involved in immune recognition and growth control that are nonessential for viral replication. The encoded virokines and viroceptors may act as mimetics or antagonists of their cellular homologues, altering signal transduction and cell communication towards survival of virus‐infected cells. Human herpesvirus type 8 (HHV8) is the most recently identified human oncogenic herpesvirus. It is associated with Kaposis sarcoma and lymphoproliferative diseases, such as pleural effusion lymphomas and multicentric Castlemans disease. HHV8 has captured a unique number of cellular regulatory genes, which redirect gene expression and cell growth, prevent apoptosis and immune recognition, and interfere with tumor suppressor gene function. HHV8 encodes a unique virokine, viral interleukin‐6, which is particularly relevant for the pathogenesis of HHV8‐associated tumors, since it participates in transformation and mediates autocrine and paracrine mitogenic and proinflammatory effects. Viral IL‐6 differs fundamentally from human IL‐6 in receptor engagement for signal transduction and thus constitutes a singular model to understand the facets of human and viral cytokine biology. We provide an overview of the role of virokines in cancer, with a particular focus on the differences of human and viral IL‐6 in the pathophysiology of HHV8‐associated tumors.

Gene Expression Profiling of Human Cancers

Abstract: DNA microarrays allow us to visualize simultaneously the expression of potentially all genes within a cell population or tissue sample—revealing the “transcriptome.” The analysis of this type of data is commonly called “gene expression profiling” (GEP) because it provides a comprehensive picture of the pattern of gene expression in a particular biological sample. For this reason microarrays are revolutionizing life sciences research and are leading to the development of novel and powerful methods for investigating cancer biology, classifying cancers, and predicting clinical outcome of cancers. Several recent high‐profile reports have revealed how clustering of GEP data can clearly identify clinically (and prognostically) important subtypes of cancer among patients considered by established clinicopathological criteria to have similar tumors. Accurate “prognostic signatures” can be obtained from GEP data, which represent relatively small numbers of genes. These signatures can be valuable in directing appropriate treatment and in predicting clinical outcome, and they generally outperform other systems based on clinical and histological criteria. In this paper the basic principles of DNA microarray technology and the different types of microarray platforms available will be introduced, and the power of the technique will be illustrated by reviewing some recent GEP studies on selected cancers, including a preliminary analysis of hepatocellular carcinoma from our Palermo laboratory. GEP is likely to be adopted in the future as a key decision‐making tool in the clinical arena. However, several issues relating to data analysis, reproducibility, cross‐comparability, validation, and cost need to be resolved before the technology can be adopted broadly in this context.

Estrogen regulates cytokine production and apoptosis in PMA-differentiated, macrophage-like U937 cells

We have investigated the effects of sex steroids, estradiol (E2), and testosterone (T) on the synthesis of tumor necrosis factor alpha (TNF‐α) and interleukin‐10 (IL‐10) in phorbol‐myristate‐acetate (PMA)‐differentiated human monoblastic U937 cells. The ability of both hormones to modulate the viability and programmed cell death of macrophage‐like PMA‐differentiated U937 cells was also inspected. E2 increased TNF‐α synthesis, whereas T had no effect on the production of this cytokine. The combination of E2 and its antagonist tamoxifen or ICI‐182,789 completely abolished the induction of TNF‐α, while combination of T and its antagonist Casodex (CSDX) did not significantly affect TNF‐α production by U937 cells. Exposure of cells to E2 resulted in a dose‐dependent decrease of IL‐10 synthesis, while again T did not show any detectable effect. In addition, E2 induced a significant increase of apoptosis in macrophage‐like U937 cells and this increase was inhibited by the simultaneous addition of either tamoxifen or ICI‐182. In contrast, T alone or in combination with CSDX did not modify apoptotic rates of U937 cells. This evidence, taken together, suggests that estrogens, but not androgens, exert a pro‐inflammatory action through the modulation of TNF‐α and IL‐10, and regulate the immune effector cells by the induction of programmed cell death. J. Cell. Biochem. 90: 187–196, 2003.

Endocrine End‐Points in Rheumatoid Arthritisa

ABSTRACT: Our previous studies are reviewed and at the same time preliminary experimental observation to the topic of endocrine end‐points in autoimmune disease is introduced. To this end, we have used rheumatoid arthritis (RA), including synovial fluids and primary cultures of synovial macrophages, as a model system in order to investigate (a) expression and subcellular localization of high‐affinity sites of steroid binding in immune effector cells; (b) steroid metabolic profiles in both male and female RA patients, as compared to healthy subjects; and (c) activities of key steroid enzymes that govern intratissue accumulation of sex hormones.

Truncated Form of β‐Catenin and Reduced Expression of Wild‐Type Catenins Feature HepG2 Human Liver Cancer Cells

GIUSEPPE CARRUBA, a,e MELCHIORRE CERVELLO,b MARIA D. MICELI,a ROSARIA FARRUGGIO,a MONICA NOTARBARTOLO,c LUCREZIA VIRRUSO,b LYDIA GIANNITRAPANI,d ROBERTO GAMBINO,b GIUSEPPE MONTALTO,d AND LUIGI CASTAGNETTAa,c aInstitute of Oncology, and dInstitute of Internal Medicine, University of Palermo, Palermo, Italy bInstitute of Developmental Biology, C.N.R., Palermo, Italy cExperimental Oncology, Palermo Branch of IST-Genoa, c/o M. Ascoli Cancer Hospital Center, Palermo, Italy

Expression of Different 17β-Hydroxysteroid Dehydrogenase Types and Their Activities in Human Prostate Cancer Cells1

The 17beta-hydroxysteroid dehydrogenase (17betaHSD) enzyme system governs important redox reactions at the C17 position of steroid hormones. Different 17betaHSD types (no. 1-4) have been identified to date in peripheral human tissues, such as placenta, testis, and breast. However, there is little information on their expression and activity in either normal or malignant prostate. In the present work, we have inspected pathways of 17beta-oxidation of either androgen or estrogen in human prostate cancer cells (LNCaP, DU145, and PC3) in relation to the expression of messenger RNAs (mRNAs) for 17betaHSD types 1-4. These cell systems feature distinct steroid receptor status and response to hormones. We report here that high expression levels of 17betaHSD4 were consistently observed in all three cell lines, whereas even greater amounts of 17betaHSD2 mRNA were detected solely in PC3 cells. Neither 17betaHSD1 nor 17betaHSD3 mRNAs could be detected in any cell line. From a metabolic standpoint, intact cell analysis showed a much lower extent of 17beta-oxidation of both androgen [testosterone (T)] and estrogen [estradiol (E2)] in LNCaP and DU145 cells compared to PC3 cells, where a greater precursor degradation and higher formation rates of oxidized derivatives (respectively, androstenedione and estrone) were observed. Using subcellular fractionation, we have been able to differentiate among 17betaHSD types 1-4 on the basis of their distinct substrate specificities and subcellular localization. This latter approach gave rise to equivalent results. PC3 cells, in fact, displayed a high level of microsomal activity with a low E2/T activity ratio and approximately equal apparent Km values for E2 and T, suggesting the presence of 17betaHSD2. Dehydrogenase specific activity with both E2 and T was also detected, although at lower levels, in LNCaP and DU145 cells. No evidence for reductase activity could be obtained in either the soluble or microsomal fraction of any cell line. As comparable expression levels of 17betaHSD4 were seen in the three cell lines, 17betaHSD2 is a likely candidate to account for the predominant oxidative activity in PC3 cells, whereas 17betaHSD4 may account for the lower extent of E2 oxidation seen in both LNCaP and DU145 cells. This is the first report on the expression of four different 17betaHSD types in human prostate cancer cells. It ought to be emphasized that for the first time, analysis of different 17betaHSD activities in either intact or fractionated cells harmonizes with the expression of relevant mRNAs species.