Role of eicosanoids in prostate cancer progression

Metabolism of arachidonic acid through cyclooxygenase, lipoxygenase, or P450 epoxygenase pathways leads to the formation of various bioactive eicosanoids. In this review, we discuss alterations in expression pattern of eicosanoid-generating enzymes found during prostate tumor progression and expound upon their involvement in tumor cell proliferation, apoptosis, motility, and tumor angiogenesis. The expression of cyclooxygenase-2, 12-lipoxygenase, and 15-lipoxygenase-1 are up-regulated during prostate cancer progression. It has been demonstrated that inhibitors of cyclooxygenase-2, 5-lipoxygenase and 12-lipoxygenase cause tumor cell apoptosis, reduce tumor cell motility and invasiveness, or decrease tumor angiogenesis and growth. The eicosanoid product of 12-lipoxygenase, 12(S)-hydroeicosatetraenoic acid, is found to activate Erkl/2 kinases in LNCaP cells and PKCalpha in rat prostate AT2.1 tumor cells. Overexpression of 12-lipoxygenase and 15-lipoxygenase-1 in prostate cancer cells stimulate prostate tumor angiogenesis and growth, suggesting a facilitative role for 12-lipoxygenase and 15-lipoxygenase-1 in prostate tumor progression. The expression of 15-lipoxygenase-2 is found frequently to be lost during the initiation and progression of prostate tumors. 15(S)-hydroxyeicosatetraenoic acid, the product of 15-lipoxygenase-2, inhibits proliferation and causes apoptosis in human prostate cancer cells, suggesting an inhibitory role for 15-lipoxygenase-2 in prostate tumor progression. The regulation of prostate cancer progression by eicosanoids, in either positive or negative ways, provides an exciting possibility for management of this disease.

Interplay of anions and ligands on the nature and reducibility of NiOx/Al2O3 catalysts prepared by impregnation

When NiOx/Al2O3 catalysts (Ni wt% = 1.5) are prepared by impregnation using [NiL2(H2O)2]X2 as precursors (L = diamine, X = Cl- or NO3-), a supported oxidic or metallic phase can be selectively obtained after thermal treatment in N2 depending on the nature of the ligand and counter anion; the oxidic phase can be reduced at a lower temperature than the classical nickel aluminate phase obtained from [Ni-(H2O)6](NO3)2.

Ciliated epithelia in the urethra: case report and literature review

The presence of ciliated epithelial cells in the urethra has not been well recognized. Only two reports in the literature, both of which used scanning microscopy studies, have described this phenomenon. In this report, we illustrate the presence of scattered, ciliated epithelial cells in penile urethral biopsy specimens from a 38-year-old man with a history of bladder calculi and hematuria, by both light and transmission electron microscopy studies. The cilia in the urethra showed typical light microscopic and ultrastructural features of those seen in other organs. These ciliated cells are present in association with urothelial papilloma, condyloma acuminatum and acute inflammation of the urethra. These findings suggest that ciliated cells in the penile 0 urethra might be a consequence of metaplastic change of the urothelium, secondary to local stimulation or irritation.

Ovarian mixed-epithelial carcinomas with a microcystic pattern and signet-ring cells

Primary ovarian carcinomas with unusual histologic patterns can be difficult to differentiate from metastases. In this study, we reviewed 15 cases of mixed-epithelial carcinoma (12 serous, 1 serous and endometrioid, 1 endometrioid, 1 undifferentiated) with a predominant microcystic pattern and signet-ring cells. The patients' ages ranged from 31 to 78 (mean 58) years. The microcystic component in 11 patients had features of high-grade carcinoma and in 4 patients had features of low-grade carcinoma associated with areas of borderline tumor. The tumors in all 15 patients showed a predominant microcystic growth pattern composed of small cysts that were variable in size and shape. Signet-ring cells were also present in all cases (diffusely in nine cases, focally in six cases) within the neoplastic epithelial proliferation. Mucin was present in the lumina of some of the microcysts and in the cytoplasm of most of the signet-ring cells. A microcystic pattern and mucin-containing signet-ring cells can be seen as small foci or as a predominant component in primary epithelial nonmucinous ovarian carcinomas. It is important for pathologists to recognize these unusual findings in ovarian neoplasms, because they may produce a confusing apperance, even potentially suggesting a metastasis.

Mononuclear phagocyte differentiation, activation, and viral infection regulate matrix metalloproteinase expression: implications for human immunodeficiency virus type 1-associated dementia

The pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is mediated mainly by mononuclear phagocyte (MP) secretory products and their interactions with neural cells. Viral infection and MP immune activation may affect leukocyte entry into the brain. One factor that influences central nervous system (CNS) monocyte migration is matrix metalloproteinases (MMPs). In the CNS, MMPs are synthesized by resident glial cells and affect the integrity of the neuropil extracellular matrix (ECM). To ascertain how MMPs influence HAD pathogenesis, we studied their secretion following MP differentiation, viral infection, and cellular activation. HIV-1-infected and/or immune-activated monocyte-derived macrophages (MDM) and human fetal microglia were examined for production of MMP-1, -2, -3, and -9. MMP expression increased significantly with MP differentiation. Microglia secreted high levels of MMPs de novo that were further elevated following CD40 ligand-mediated cell activation. Surprisingly, HIV-1 infection of MDM led to the down-regulation of MMP-9. In encephalitic brain tissue, MMPs were expressed within perivascular and parenchymal MP, multinucleated giant cells, and microglial nodules. These data suggest that MMP production in MP is dependent on cell type, differentiation, activation, and/or viral infection. Regulation of MMP expression by these factors may contribute to neuropil ECM degradation and leukocyte migration during HAD.

Regulation of human immunodeficiency virus type 1 infection, beta-chemokine production, and CCR5 expression in CD40L-stimulated macrophages: immune control of viral entry

Mononuclear phagocytes (MP) and T lymphocytes play a pivotal role in the host immune response to human immunodeficiency virus type 1 (HIV-1) infection. Regulation of such immune responses can be mediated, in part, through the interaction of the T-lymphocyte-expressed molecule CD40 ligand (CD40L) with its receptor on MP, CD40. Upregulation of CD40L on CD4+ peripheral blood mononuclear cells during advanced HIV-1 disease has previously been reported. Based on this observation, we studied the influence of CD40L-CD40 interactions on MP effector function and viral regulation in vitro. We monitored productive viral infection, cytokine and beta-chemokine production, and beta-chemokine receptor expression in monocyte-derived macrophages (MDM) after treatment with soluble CD40L. Beginning 1 day after infection and continuing at 3-day intervals, treatment with CD40L inhibited productive HIV-1 infection in MDM in a dose-dependent manner. A concomitant and marked upregulation of beta-chemokines (macrophage inhibitory proteins 1alpha and 1beta and RANTES [regulated upon activation normal T-cell expressed and secreted]) and the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) was observed in HIV-1-infected and CD40L-treated MDM relative to either infected or activated MDM alone. The addition of antibodies to RANTES or TNF-alpha led to a partial reversal of the CD40L-mediated inhibition of HIV-1 infection. Surface expression of CD4 and the beta-chemokine receptor CCR5 was reduced on MDM in response to treatment with CD40L. In addition, treatment of CCR5- and CD4-transfected 293T cells with secretory products from CD40L-stimulated MDM prior to infection with a CCR5-tropic HIV-1 reporter virus led to inhibition of viral entry. In conclusion, we demonstrate that CD40L-mediated inhibition of viral entry coincides with a broad range of MDM immune effector responses and the down-modulation of CCR5 and CD4 expression.