TGF-ß/PI3K/AKT/mTOR/NF-kB pathway. Clinicopathological features in prostate cancer.

Prostate cancer is one of the most common cancers in the male population. The objective of this investigation was to study the relationship of components of transforming growth factor-B (TGF-ß)/phosphoinositide-3-kinases (PI3K)/AKT/mammalian target of rapamycin (mTOR)/nuclear factor kappa B (NF-kB) transduction pathway with clinical-pathological markers. By immunohistochemical methods, we determined the expression of several factors [TGF-ß, Transforming Growth Factor B Receptor I (TGFBRI), TGFBRII, PI3K, AKT-Ser, AKT-Thr, mTOR, p-mTOR, inhibitor kB kinase (IKK), pIKK, inhibitor kB (IkB), pIkB, NF-kBp50, and NF-kBp65]. To know their relationship with established classical markers (Preoperative serum prostate specific antigen, pathological tumor stage, clinical tumor stage, Gleason score, perineural invasion, node involvement, positive surgical margins, biochemical progression, and survival) and their importance in the prognosis of biochemical progression, Spearman test, survival analysis, Log-rang test, Kaplan-Meier curves, univariate and multivariate Cox proportional Hazard regression analyses were performed. Spearman analysis showed that there was at least one correlation between TGF-ß, TGFBRI, PI3K, pAKT-Thr, p-mTOR, NF-kBp50, and classical markers. Cox multivariate analysis between the prognostic variables (pathological tumor stage, Gleason score, and node involvement) and inmunohistochemical parameters confirmed TGFBR1 and PI3K as a prognostic and independent marker of biochemical progression in prostate cancer. Our results suggest that TGFBR1 and PI3K could be used as useful biomarkers for early diagnosis and prognoses for biochemical recurrence in prostate cancer after radical prostatectomy.

Homeostasis: apoptosis and cell cycle in normal and pathological prostate.

Prostatic diseases such as hyperplasia and cancer are a consequence of glandular aging due to the loss of homeostasis. Glandular homeostasis is guaranteed by the delicate balance between production and cell death. Both cell renewal and apoptosis are part of this delicate balance. We will explore the predictive capacity for biochemical progression, following prostatectomy, of some members of the Bcl-2 family and of proteins involved in cell cycle inhibition in conjunction with established classical markers. The expression of Bcl-2, Bcl-xL, Mcl-1, Bax, Bim, Bad, PUMA, Noxa, p21, p27, Rb and p53 were analyzed by immunochemistry in 86 samples of radical prostatectomy and correlated with each of the markers established clinicopathological tests using statistical tests such as Sperman, Kaplan-Meier curves, unifactorial Cox, and multifactorial. The most relevant results are: (1) Positive correlation between: p27 with clinical T stage; and PUMA with pathological T stage; (2) Negative correlation between: Bcl-2 with clinical T stage, Bcl-xL with survival, Noxa and pRb with Gleason score.Our results suggest that the expression of Bcl-2, Bcl-xL, PUMA, Noxa, p27, and Rb were related to some of the classic markers established to predict biochemical progression after prostatectomy.

PI3K pathway and Bcl-2 family. Clinicopathological features in prostate cancer.

The phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathways and Bcl-2 family play a central role in prostate cancer (PC). The aim was to determine influence in the biochemical progression in PC. To evaluate the association between clinic pathological and immunohistochemical variables, Spearman's test was performed. Log-rank test and Kaplan-Meier curves were used for survival comparisons. To explore the correlation of the studied immunohistochemical parameters and the established prognostic variables with biochemical progression, univariate and multivariate Cox proportional Hazard regression analyses were performed. Spearman analysis showed correlation between stroma expression and tumor expression of PI3K with biochemical progression (p = .009, p = .004), respectively, and tumor immunohistochemical score with biochemical progression (p = .051). In the multivariate Cox regression model, only PI3K was retained as independent predictors of biochemical progression. In stroma expression, PI3K is (HR 0.172, 95% CI 0.065-0.452, p = .000); tumor expression, PI3K is (HR 0.087, 95% CI 0.026-0.293, p = .000), and tumor immunohistochemical score (HR 0.382, 95% CI 0.209-0.697 p = .002). Our results suggest a role for prostatic expression of PI3K was prognostic markers for PC. PI3K/AKT/mTOR and Bcl-2 family are becoming an important therapeutic target and predictive biomarkers of onset and progression of PC.

Xyloglucan, hibiscus and propolis for the prevention of urinary tract infections: results of in vitro studies.

AIM: To assess the properties of a medical device containing xyloglucan, propolis and hibiscus to create a bioprotective barrier to avoid the contact of uropathogenic Escherichia coli strains on cell walls in models of intestinal (CacoGoblet) and uroepithelial (RWPE-1) cells (derived from normal human prostate epithelium). MATERIALS & METHODS: Two uropathogenic E. coli strains (expressing type 1 fimbriae and P fimbriae) were used to assess, by electronic microscopy and ELISA, the barrier properties of the medical device. The antimicrobial activity was assessed in broth dilution assays. RESULTS: The three components (xyloglucan, propolis and hibiscus) did not alter E. coli cell integrity in intestinal and uroepithelial cell models and were devoid of antibacterial activity. The three components avoided bacterial contact in both cell monolayers. CONCLUSION: The nonpharmacological barrier properties of xyloglucan, propolis and hibiscus confirm the role of the medical device for the management of urinary tract infections.

Expression of several cytokines in prostate cancer: Correlation with clinical variables of patients. Relationship with biochemical progression of the malignance.

BACKGROUND: This work is focused on finding new markers that complement or diagnoses currently used towards improving knowledge histological and statistical aspects that allow us to predict the local stage carcinomas and to identify and understand all the factors related to the progression of this disease. MATERIALS AND METHODS: Prostates were obtained from: normal prostates from 20 men, diagnosis of BPH (Benign Prostatic Hyperplasia) from 35 men and prostate cancer from 86 men. We studied the behavior of cytokines that have been implicated in inflammatory processes: TNF-alfa, IL-6, IL-1, EGF and TGF-B. Expression of these cytokines and its receptors was analyzed by immunohistochemistry. Spearman's test, Kaplan-Meier curves, univariate and multivariate Cox proportional hazard regression analyses were performed. RESULTS: Spearman's analysis showed that there was at least one correlation between TGFB-B, IL-6, gp-130, IL-1B, IL-1R, IL-1RII and clinic pathological feature (preoperative serum PSA, clinical t stage, pathological t stage, positive surgical margins, biochemical progression, survival). Immunostaining score was correlated with some of the clinicopathological feature. In Cox multivariate analysis between the prognostic variables (pathological T stage, Gleason score and lymph node) and immunohistochemical parameters (TGF-B, IL-1a, intensity TGFBRI and intensity TGFBRII) only the expression of IL-1a was retained as independent predictors of biochemical progression after radical prostatectomy. CONCLUSIONS: Our results suggest a role for prostatic expression of TGF-B, IL-1a, TGFBRI and TGFBRII as prognostic markers for prostate cancer. The rational combination of novel agents directed toward the inactivation of TGF-B, IL-1a, TGFBRI and TGFBRII could disrupt complementary tumor cell proliferation pathways.

Epidermal growth factor induces p38 MAPK-dependent G0/G1-to-S transition in prostate cancer cells upon androgen deprivation conditions.

Epidermal growth factor (EGF) is thought to contribute to the emergence of castration-resistant (CR) prostate tumors by inducing proliferation of cancer cells despite the low levels of circulating androgens achieved by androgen deprivation therapy. We show that, in LNCaP cells, androgen deprivation induces arrest in the G0/G1 cell cycle phase, and that EGF partially rescues this arrest without affecting cell death. Inhibition of p38 MAPK, but not MEK or IKK-ß, completely abrogates the EGF-induced proliferation of LNCaP cells in androgen-depleted medium, and decreases the fraction of G0/G1-arrested cells. Our results suggest that EGF enables prostate cancer cells to overcome the growth restriction imposed by androgen deprivation by stimulating G0/G1-to-S transition via p38 MAPK. These results suggest the potential of developing therapies for advanced prostate cancer that block the G0/G1 to S transition, such as by targeting p38 MAPK, or that aim to induce apoptosis in G0/G1-arrested cancer cells.

Prognostic value of inhibitors of apoptosis proteins (IAPs) and caspases in prostate cancer: caspase-3 forms and XIAP predict biochemical progression after radical prostatectomy.

BACKGROUND: The expression status of apoptotic regulators, such as caspases and inhibitors of apoptosis proteins (IAPs), could reflect the aggressiveness of tumors and, therefore, could be useful as prognostic markers. We explored the associations between tumor expression of caspases and IAPs and clinicopathological features of prostate cancer--clinical and pathological T stage, Gleason score, preoperative serum PSA levels, perineural invasion, lymph node involvement, surgical margin status and overall survival--and evaluated its capability to predict biochemical progression after radical prostatectomy. METHODS: Protein expression of caspases (procaspase-8, cleaved caspase-8, procaspase-3, cleaved caspase-3, caspase-7 and procaspase-9) and IAPs (cIAP1/2, cIAP2, NAIP, Survivin and XIAP) was analyzed by immunohistochemistry in radical prostatectomy samples from 84 prostate cancer patients. Spearman's test, Kaplan-Meier curves, and univariate and multivariate Cox proportional hazard regression analysis were performed. RESULTS: cIAP1/2, cIAP2, Survivin, procaspase-8, cleaved caspase-8, procaspase-3 and caspase-7 expression correlated with at least one clinicopathological feature of the disease. Patients negative for XIAP, procaspase-3 or cleaved caspase-3 had a significantly worse prognosis. Of note, XIAP, procaspase-3 and cleaved caspase-3 were predictors of biochemical progression independent of Gleason score and pathological T stage. CONCLUSIONS: Our results indicate that alterations in the expression of IAPs and caspases contribute to the malignant behavior of prostate tumors and suggest that tumor expression of XIAP, procaspase-3 and cleaved caspase-3 may help to identify prostate cancer patients at risk of progression.

Clinical significance of both tumor and stromal expression of components of the IL-1 and TNF-α signaling pathways in prostate cancer.

IL-1 and TNF-α, the two major proinflammatory cytokines, have been involved in initiation and progression of several malignancies. They could influence the biological behavior of prostatic tumors and patient outcome, and could be useful as prognostic factors. This study evaluated the prognostic capability for biochemical progression after radical prostatectomy of expression of IL-1, TNF-α and related signaling components, in the tumor and surrounding stroma, as well as its correlation with other clinicopathological features. Expression of IL-1α, IL-1ß, IL-1Ra, IL-1RI, IL-1RII, IRAK-1, TRAF6, TNF-α, TNFRI and TRAF2 was analyzed by immunohistochemistry in radical prostatectomy samples from 93 prostate cancer patients. Spearman's test, Kaplan-Meier curves, and univariate and multivariate Cox proportional hazard regression analyses were performed. Expression of TNF-α, TNFRI, TRAF2, ILRI, IRAK-1 and TRAF6 correlated with at least one clinicopathological feature (clinical T stage, pathological T stage, preoperative serum PSA or Gleason score). Increased tumor expression of TNF-α, TNFRI and IL-1RI, and reduced tumor expression of IRAK-1 were significantly correlated with a poor prognosis in univariate analysis. Reduced stromal expression of IL-1ß and IL-1RII, and increased stromal expression of IRAK-1 were also adverse prognostic factors in univariate analysis. Remarkably, tumor IL-1ß and stromal IL-1RII and IRAK-1 remained as independent prognostic factors after adjustment for preoperative serum PSA, pathological T stage and Gleason score in multivariate Cox models. Our results suggest that prostatic expression of TNF-α, IL-1ß and related signaling proteins (TNFRI, IL-1RI, IL-1RII and IRAK-1) predicts clinical outcome in prostate cancer, and support the involvement of TNF-α and IL-1ß signaling in prostate cancer progression.

MAP Kinases and Prostate Cancer.

The three major mitogen-activated protein kinases (MAPKs) p38, JNK, and ERK are signal transducers involved in a broad range of cell functions including survival, apoptosis, and cell differentiation. Whereas JNK and p38 have been generally linked to cell death and tumor suppression, ERK plays a prominent role in cell survival and tumor promotion, in response to a broad range of stimuli such as cytokines, growth factors, ultraviolet radiation, hypoxia, or pharmacological compounds. However, there is a growing body of evidence supporting that JNK and p38 also contribute to the development of a number of malignances. In this paper we focus on the involvement of the MAPK pathways in prostate cancer, including the less-known ERK5 pathway, as pro- or antitumor mediators, through their effects on apoptosis, survival, metastatic potential, and androgen-independent growth.

Immunoreactivity to caspase-3, caspase-7, caspase-8, and caspase-9 forms is frequently lost in human prostate tumors.

Caspases are essential initiators and executioners of apoptosis. Changes in their expression may contribute to the development of proliferative disorders such as cancer, by altering the death-proliferation homeostatic balance. The aim of this work was to analyze the expression of a broad panel of caspases at the epithelial level in human prostate tissues to assess possible prostatic disease-related alterations. We comparatively analyzed by immunohistochemistry the expression of pro-caspase-3, pro-caspase-8, pro-caspase-9, cleaved caspase-3, cleaved caspase-8, and caspase-7, in normal and pathologic (benign hyperplasic, premalignant [high-grade intraepithelial neoplasia], and cancerous [prostate cancer]) human prostate epithelium. Expression of caspases was correlated with clinicopathologic features, including preoperative prostate-specific antigen levels, Gleason scores, and biochemical progression. Percentage of positive samples for all the analyzed caspases decreased in prostate cancer versus normal prostate epithelium. The values obtained for benign prostatic hyperplasia and high-grade intraepithelial neoplasia more qualitatively resembled those of the prostate cancer group. Our results indicate that caspase expression in prostate malignant cells is reduced in a substantial number of patients and that such an alteration occurs in the premalignant stage. Loss of caspase expression could constitute a useful marker for prostate cancer diagnosis. Therapeutic approaches aimed to recover or enhance caspase expression might be effective against prostate cancer.

Expression of NF-κB-related proteins and their modulation during TNF-α-provoked apoptosis in prostate cancer cells.

BACKGROUND: The involvement of TNF-α in cancer development is controversial, since this cytokine was reported to act either as tumor promoter or suppressor. TNF-α may activate signaling pathways critical for life/death decisions, such as mitogen-activated protein kinases (MAPKs) and the anti-apoptotic NF-κB pathway. In this work, we investigate the activation status of NF-κB-related proteins in human prostate cancerous versus normal epithelium, and the alterations in the NF-κB pathway in relation to cell death in TNF-α-treated LNCaP (androgen-independent cells) and PC3 (androgen-independent) prostate cancer cell lines. METHODS: The expression of phospho-p38-MAPK, phospho-IKK-α/ß and phospho-IκB-α, total IκB-α, and p65- and p50-NF-κB, were analyzed by immunohistochemistry in cancerous and normal prostate samples. The toxicity of TNF-α in LNCaP and PC3 cells, with or without kinase and NF-κB inhibitors, was assessed by changes on viability (MTT assay) and apoptosis (loss of DNA, annexin-V binding, and caspase cleavage/activation). Expression of NF-κB-related proteins in these cell lines was measured by Western blot. RESULTS: Phospho-IκB-α, phospho-IKK-α/ß and phospho-p38 levels, cytoplasmic p50 to IκB-α ratio, and nuclear p50 and p65, levels, were increased in cancerous epithelium, suggesting activation of the NF-κB pathway in prostatic malignance. TNF-α caused apoptosis with higher efficacy in LNCaP cells, and this response was potentiated by p38-MAPK inhibitor (LNCaP cells) and IKK-ß inhibitor (both cell lines). However, the protective action of IKK-ß was mediated by NF-κB only in LNCaP cells. CONCLUSIONS: IKK-ß mediates both NF-κB-dependent and -independent anti-apoptotic functions in prostate cancerous epithelium. IKK-ß and p38-MAPK may represent useful therapeutic targets against prostate cancer.

Relationship between IL-6/ERK and NF-κB: a study in normal and pathological human prostate gland.

BACKGROUND: There is growing evidence that inflammation is a causal factor in cancer, where pro-inflammatory cytokines such as IL-6, IL-1 or TNF-α could induce cellular proliferation by activation of NF-κB. This study focuses on the IL-6/ERK transduction pathway, its relationship with NF-κB, and the consequences of dysregulation in the development of prostate pathologies such as benign prostate hyperplasia (BPH), prostate intraepithelial neoplasia (PIN) and prostate cancer (PC). METHODS: Immunohistochemical and Western blot analyses for IL-6, gp-130, Raf-1, MEK-1, ERK-1, p-MEK, ERK-2, p-ERK, NF-κB/p-50 and NF-κB/p-65 were carried out in 20 samples of normal prostate glands, 35 samples of BPH, 27 samples with a diagnosis of PIN (low-grade PIN or high-grade PIN), and 95 samples of PC (23 with low, 51 with medium and 21 with high Gleason scores). RESULTS: Immunoreaction to IL-6, gp-130, ERK-1, ERK-2, p-ERK and NF-κB/p50 was found in the cytoplasm of epithelial cells in normal prostate samples; p-MEK was found in the nucleus of epithelial cells; but not expression to Raf-1, MEK-1 and NF-κB/p65. In BPH, all of these proteins were immunoexpressed, while there was increased immunoexpression of IL-6, gp-130, p-MEK, ERK-1, ERK-2 and NF-κB/p50 (cytoplasm). In PC, immunoexpression of IL-6 and gp-130 were similar to that found in BPH; while immunoexpression of Raf-1, MEK-1, p-MEK, ERK-1, ERK-2, p-ERK, NF-κB/p50 (nucleus and cytoplasm), and NF-κB/p65 (nucleus and cytoplasm) was higher than in BPH. CONCLUSION: Translocation of NF-κB to the nucleus in PC and high-grade PIN could be stimulated by the IL-6/ERK transduction pathway, but might also be stimulated by other transduction pathways, such as TNF-α/NIK, TNF/p38, IL-1/NIK or IL-1/p38. Activation of NF-κB in PC could regulate IL-6 expression. These transduction pathways are also related to activation of other transcription factors such as Elk-1, ATF-2 or c-myc (also involved in cell proliferation and survival). PC is a heterogeneous disease, where multiple transduction pathways might alter the apoptosis/proliferation balance. Significant attention should be give to the combination of novel agents directed towards inactivation of pro-inflammatory cytokines than can disrupt tumour cell growth.

The biological response modifier AM3 attenuates the inflammatory cell response and hepatic fibrosis in rats with biliary cirrhosis.

BACKGROUND: An inflammatory immune system response ensues in the liver and in the systemic circulation in cirrhosis, where it contributes to hepatic fibrosis and peripheral vasodilation. Modulation of the inflammatory response without increasing susceptibility to infection is a therapeutic target in cirrhosis. AM3 is a low-toxicity biological response modifier with regulatory effects on innate and adaptative immunity, and the ability to normalise the production of tumour necrosis factor alpha (TNFalpha). AIMS: This was an experimental study to investigate the effects of oral AM3 on the systemic and hepatic inflammatory response, liver fibrosis and on the haemodynamic abnormalities of portal hypertension in rats with biliary cirrhosis. DESIGN: Bile-duct ligated rats received a 3-week oral course of AM3 or placebo. RESULTS: In cirrhotic rats, AM3 blunted the inflammatory switch of circulating and intrahepatic monocytes and T-cells to TNFalpha and interferon gamma (IFNgamma) production, respectively. AM3 modified the intrahepatic polarisation pattern of the regulatory cytokines, decreasing the mRNA expression of transforming growth factor beta1 (TGFbeta1), interleukin 4 (IL4), and IFNgamma, and increasing that of IL10. Total and IFNgamma-producing natural killer (NK) cells were lowered by AM3 in the peripheral blood and liver of cirrhotic rats. The immunomodulatory effects of AM3 led to reduced hepatic fibrogenesis in cirrhotic rats, as shown by decreased area of liver fibrosis, hydroxyproline content and mRNA expression of procollagen alpha1(I). Besides, AM3 lowered portal pressure and systemic hyperaemia. CONCLUSIONS: The biological response modifier AM3 reverses the concurrent inflammatory immune system activation in peripheral blood and liver of experimental established cirrhosis, which results in reductions of hepatic fibrosis, portal pressure and peripheral vasodilation.

Role of IAPs in prostate cancer progression: immunohistochemical study in normal and pathological (benign hyperplastic, prostatic intraepithelial neoplasia and cancer) human prostate.

BACKGROUND: In this study was investigate IAPs in normal human prostate (NP), benign prostatic hyperplasia (BPH), prostatic intraepithelial neoplasia (PIN) and prostatic carcinoma (PC), and their involvement in apoptosis/proliferation via NF-kB (TNF-alpha, IL-1) stimulation. METHODS: Immunohistochemical and Western blot analyses were performed in 10 samples of normal prostates, 35 samples of BPH, 27 samples diagnosis of PIN (with low-grade PIN or high-grade PIN) and 95 samples of PC (with low, medium or high Gleason grades). RESULTS: In NP, cytoplasm of epithelial cells were positive to c-IAP1/2 (80% of samples), c-IAP-2 (60%), ILP (20%), XIAP (20%); negative to NAIP and survivin. In BPH, epithelial cells were immunostained to c-IAP1/2 (57.57%), c-IAP-2 (57.57%), ILP (66.6%), NAIP (60.6%), XIAP (27.27%), survivin (9.1%). Whereas low-grade PIN showed intermediate results between NP and BPH; results in high-grade PIN were similar to those found in PC. In PC, epithelial cells were immunostained to c-IAP1/2, c-IAP-2, ILP, NAIP, XIAP (no Gleason variation) and survivin (increasing with Gleason). CONCLUSIONS: IAPs could be involved in prostate disorder (BPH, PIN and PC) development since might be provoke inhibition of apoptosis and subsequently cell proliferation. At the same time, different transduction pathway such as IL-1/NIK/NF-kB or TNF/NF-kB (NIK or p38) also promotes proliferation. Inhibitions of IAPs, IL-1alpha and TNFalpha might be a possible target for PC treatment since IAPs are the proteins that inhibited apoptosis (favour proliferation) and IL-1alpha and TNFalpha would affect all the transduction pathway involucrate in the activation of transcription factors related to survival or proliferation (NF-kB, Elk-1 or ATF-2).

The profile of prostate epithelial cytokines and its impact on sera prostate specific antigen levels.

The aim of this study was determined the expression of pro inflammatory cytokines in prostate epithelial cells. Furthermore, we analysed the relation between these cytokines and sera PSA levels according the three groups: 0-4, 4-20 and >20 ng/mL. The study was carried out in five normal prostate (NP), 27 benign prostate hyperplastic (BPH) and 18 prostate cancer (PC). Immunohistochemical and Western blot analysis was performed. Serum levels of PSA were assayed by Immulite autoanalyser. The western Blotting analysis revealed an immunoexpression of IL-1alpha, IL-6 and TNFalpha in BPH and PC. IL-1alpha, was absent in NP. Immunohistochemical analysis showed significant high optical density to IL-1alpha and IL-6 in cancer epithelial cells (19.45 +/- 3.25 and 26.2 +/- 3.19) compared to normal cells (1.73 +/- 1.51 and 4.83 +/- 2.65). While, TNFalpha optical densities were not significant in NP (12.03 +/- 2.9), BPH (9.87 +/- 3.85) and PC (13.34 +/- 2.34). The different profiles of cytokines according sera PSA levels showed a high immunoexpression of the profile (IL-6+, IL-1alpha+) in BPH patients with PSA between 0-4 and 4-20 ng/mL. However, PC patients with sera PSA between 4 and 20 ng/mL, showed a significant high immunoexpression of the profile (IL-6+, IL-1alpha-). This data demonstrate a locally production of pro-inflammatory cytokines by prostate epithelial cells and a cross talk between PSA and these cytokines in prostate pathologies.

Human pregnane X receptor is expressed in breast carcinomas, potential heterodimers formation between hPXR and RXR-alpha.

BACKGROUND: The human pregnane X receptor (hPXR) is an orphan nuclear receptor that induces transcription of response elements present in steroid-inducible cytochrome P-450 gene promoters. This activation requires the participation of retinoid X receptors (RXRs), needed partners of hPXR to form heterodimers. We have investigated the expression of hPXR and RXRs in normal, premalignant, and malignant breast tissues, in order to determine whether their expression profile in localized infiltrative breast cancer is associated with an increased risk of recurrent disease. METHODS: Breast samples from 99 patients including benign breast diseases, in situ and infiltrative carcinomas were processed for immunohistochemistry and Western-blot analysis. RESULTS: Cancer cells from patients that developed recurrent disease showed a high cytoplasmic location of both hPXR isoforms. Only the infiltrative carcinomas that relapsed before 48 months showed nuclear location of hPXR isoform 2. This location was associated with the nuclear immunoexpression of RXR-alpha. CONCLUSION: Breast cancer cells can express both variants 1 and 2 of hPXR. Infiltrative carcinomas that recurred showed a nuclear location of both hPXR and RXR-alpha; therefore, the overexpression and the subcellular location changes of hPXR could be considered as a potential new prognostic indicator.

Pro-inflammatory cytokines and prostate-specific antigen in hyperplasia and human prostate cancer.

BACKGROUND: The aim of this study was to relate the expression, analyzed by Western blot and immunohistochemistry, of several pro-inflammatory cytokines, including IL-1, IL-6 and TNF-alpha, with serum levels of prostate-specific antigen (PSA) in normal and pathologic (hyperplasia and cancer) prostate tissues to elucidate their possible role in tumor progression. We are also discussing the possible use of these cytokines as a potential therapeutic target. METHODS: The study was carried out in 5 normal, 25 benign prostatic hyperplastic (BPH) and 17 cancerous human prostates (PC). Immunohistochemical and Western blot analysis were performed. Serum levels of PSA were assayed by an immulite autoanalyzer. RESULTS: The most relevant results showed that in BPH, IL-1alpha, IL-6 and tumor necrosis factor (TNF) were only expressed in patients with PSA serum levels of 0-4 or 4-20 ng/ml, but not in the group >20 ng/ml. In PC these cytokines were only expressed in patients with PSA serum levels >4 ng/ml. CONCLUSIONS: In PC there was an association between the high expression of pro-inflammatory cytokines (TNFalpha, IL-6, IL-1), elevated serum levels of PSA and cancer progression. A better understanding of the biologic mechanism of this association may provide new targets for therapy in these patients.

OSM, LIF, its receptors, and its relationship with the malignance in human breast carcinoma (in situ and in infiltrative).

IL-6 cytokine family is composed by several members. IL-6, LIF, and gp130 have been associated with cancer progression. Cytokines play an important role in tumoral growth, invasion of the vessels and development of metastases. Immunoexpressions of LIF, OSM, LIFRbeta and OSMRbeta were studied in benign breast lesion, in situ and infiltrating tumors by Western blot and immunohistochemistry. Percentages of positive samples to OSM, LIF and OSMRbeta were higher in in situ carcinoma than in benign diseases and even higher in infiltrating tumors. gp130-positive samples was higher in infiltrating tumor than in benign diseases. All samples studied were LIFRbeta-positive. Infiltrating tumors showed the most intense immunostaining to LIFRbeta, OSM and OSMRbeta; comparing present results revealed an association between the expression of these proteins and increasing malignancy. In conclusions, development of breast tumor increases the expression of OSM, LIF, OSMRbeta, LIFRbeta and gp130, and this expression may be associated with the malignancy. IL-6 family exert their action through transducer receptor gp130, and gp130 expression increase with malignance, it might be a crucial point in the development of infiltrative adenocarcinoma. The secretion of OSM and LIF by both epithelial and stromal (paracrine manner) cells seems to promote tumor growth.

Glucocorticoid receptor changes its cellular location with breast cancer development.

Glucocorticoids play a major role in attenuation of the inflammatory response and they are useful in the primary combination chemotherapy of breast cancer, since in vitro studies have demonstrated an antiproliferative effect in human breast cancer cells. In contrast, it was recently shown that glucocorticoids protect against apoptotic signals evoked by cytokines, cAMP, tumour suppressors, and death genes in mammary gland epithelia. Their actions are mediated by intracellular receptor (GR) that functions as a hormone-dependent transcription factor; however, no previous studies have been focused on GR expression in different pathologies of the human breast, and the possible relationship with that of mineralocorticoid receptor (MR) and COX-2. Also, the role of these proteins on tumoral breast epithelial cells remains unclear. Therefore, we examined GR, MR and COX-2 expression by immunohistochemistry and Western blot techniques in 142 samples of human breast obtained by total or partial mastectomy. We found that the percentage of positive patients presenting nuclear immunoreaction to GR decreased with tumor development, while all samples analyzed showed cytoplasmic immunoreactions to MR. All positive samples to COX-2 antibody showed cytoplasmic location, a higher immunoreaction being observed in benign breast diseases than in carcinomatous lesions. Thus, breast cancer progression is associated with the accumulation of GR in the cytoplasm of tumoral cells and the decrease of COX-2 expression.

Influence of IFN-gamma and its receptors in human breast cancer.

BACKGROUND: Interferons are a group of proteins that trigger multiple responses including prevention of viral replication, inhibition of cell growth, and modulation of cell differentiation. In different mammary carcinoma cell lines IFNgamma induces growth arrest at mid-G1. At the present there are no in vivo studies in human breast. The aim of this study was to investigate the expression patterns of IFNgamma and its two receptors (IFNgamma-Ralpha and IFNgamma-Rbeta) by Western blot and immunohistochemistry, in order to elucidate its role in the different types of human breast cancer (in situ and infiltrative). METHODS: Immunohistochemical and semiquantitative study of IFNgamma, its receptors types (IFNgamma-Ralpha and IFNgamma-Rbeta), cell proliferation (proliferating cell nuclear antigen, also named PCNA), and apoptosis (TUNEL method) was carried between the three breast groups (fibrocystic lesions, in situ tumors and infiltrating tumors). RESULTS: In the three groups of patients, IFNgamma and IFNgamma-Ralpha immunoreactions appeared in the cytoplasm while IFNgamma-Rbeta also was found in the nucleus. The optical density to IFNgamma was higher in in situ carcinoma than in benign and infiltrating tumors. When we observed IFNgamma-Ralpha, the optical density was lower in infiltrating carcinoma than in benign and in situ tumors (the higher density). To IFNgamma-Rbeta, the optical density was similar in the three group samples. In tumor samples PCNA and TUNEL index was significantly higher; than in benign diseases. PCNA index increased with the malignance. No significant differences were found between cancer types to TUNEL. IFNgamma could be a potential therapeutic tool in breast cancer. However, tumor cells are able to escape from the control of this cytokine in the early tumor stages; this is probably due to a decreased expression of IFNgamma, or also to an alteration of either its receptors or some transduction elements. CONCLUSION: We conclude that the decrease in the % positive samples that expressed IFNgamma and IFNgamma-Ralpha together with the nuclear localization of IFNgamma-Rbeta, could be a tumoral cell response, although perhaps insufficient to inhibit the uncontrolled cell proliferation. Perhaps, IFNgamma might be unable to activate p21 to stop the cell cycle, suggesting a possible participation in breast cancer development.