Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Signaling by androgens and interferons (IFN) plays an important role in prostate cancer initiation and progression. Using microarray analysis, we describe here a functional cross-talk between dihydrotestosterone and interferon signaling. Glutathione S-transferase pull-down and co-immunoprecipitation experiments reveal that the androgen receptor and the interferon-activated RNase L interact with each other in a ligand-dependent manner. Furthermore, overexpression of wild type RNase L confers IFN sensitivity to a dihydrotestosterone-inducible reporter gene, whereas R462Q-mutated RNase L does not. Based on our data we hypothesize that in 22RV1 cells, activated androgen receptor (AR) contributes to the insensitivity to IFN of the cell. Accordingly, we show that AR knockdown restores responsiveness to IFNgamma. Our findings support a model in which both the activation of AR and the down-regulation of IFN signaling can synergize to promote cell survival and suppress apoptosis. This model provides the molecular basis to understand how mutated RNase L can lead to early onset PCa and illustrates how inflammatory cytokines and nuclear hormone signaling contribute to tumor development.
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PMID:Interaction between the androgen receptor and RNase L mediates a cross-talk between the interferon and androgen signaling pathways. 1616 78

A major hurdle in understanding the role of androgens is the heterogeneity of androgen receptor (AR) expression in the prostate. Because the majority of prostate cancer arises from the AR-positive secretory luminal epithelial cells, identifying the androgen-mediated pathways in the prostate epithelium is of great significance to understanding their role in prostate pathogenesis. To meet this objective, the current study was designed to identify immediate-early genes expressed in response to the synthetic androgen R1881 in cultured rat ventral prostate epithelial cells. Rat ventral prostate epithelial cells, purified from 20-d-old rats, were cultured, and the presence of AR and the response to androgen were established. The cells were then treated with R1881 for 2 and 12 h to capture immediate-early genes in an Affymetrix-based gene chip platform. A total of 66 nonredundant genes were identified that were responsive to R1881. The functional androgen response elements were identified in the proximal promoter to determine possible molecular mechanism. Cluster analysis identified five distinct signatures of R1881-induced genes. Pathway analysis suggested that R1881 primarily influences cell proliferation/differentiation and inflammatory/immune response pathways. Androgens appear to regulate cell renewal by regulating differentiation, cell proliferation, and apoptosis. Two mutually exclusive inflammatory response pathways were observed. The interferon pathway was up-regulated, and the ILs were down-regulated. The data identified novel androgen-regulated genes (e.g. Id1, Id3, IL-6, IGF-binding protein-2 and -3, and JunB). The loss of androgen regulation of these genes can have important consequences for cellular transformation and transition to androgen-independent growth and survival.
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PMID:Androgens regulate the immune/inflammatory response and cell survival pathways in rat ventral prostate epithelial cells. 1619 7

Many viral oncolytic approaches against cancer are based on the ability of specific viruses to replicate in tumors expressing components of the constitutively activated Ras/mitogen-activated protein kinase (MAPK) pathways and/or inhibited or dysregulated alpha/beta interferon (IFN-alpha/beta) response pathways. A major issue when considering these approaches is their applicability to tumors that lack activated Ras. To identify the effector mechanisms activated by oncolytic viruses, we investigated inhibition of proliferation of the prostate cancer line LNCap by the recombinant TR-NS1 influenza A virus, a genetically attenuated influenza A/PR8/34 virus expressing a truncated nonstructural protein (NS1) of 126 amino acids. LNCap cells lack constitutively activated MAPK, extracellular signal-regulated kinase (ERK), and p38 and are resistant to death by IFN-alpha. Truncation of the NS1 protein of influenza viruses is known to result in viral attenuation due to a reduced ability of the NS1 to inhibit the IFN-alpha/beta response. Infection with TR-NS1 virus rapidly activated ERK-1 more than ERK-2 in LNCap cells. Importantly, TR-NS1 virus infection transiently inhibited cell proliferation and induced apoptosis in LNCap cells. Addition of peripheral blood mononuclear cells (PBMC) and interleukin 12 (IL-12) to TR-NS1 virus-infected LNCap cells (TR-NS1-LNCap) resulted in faster elimination of TR-NS1-LNCap cells compared with LNCap cells. Moreover, TR-NS1-LNCap cells induced IFN-gamma in PBMC. The levels of IFN-gamma were amplified by IL-12. TR-NS1-LNCap cells also induced tumor-lytic cytotoxic T lymphocytes (CTL). These CTL lysed noninfected LNCap cells in a CD8-dependent manner. Activation of cellular immunity to tumor cells by viruses is an intriguing effector pathway, which should be especially significant for elimination of human tumors that lack activated Ras.
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PMID:Prostate tumor cells infected with a recombinant influenza virus expressing a truncated NS1 protein activate cytolytic CD8+ cells to recognize noninfected tumor cells. 1635 63

We have previously reported that adenoviral vector-mediated interferon (IFN)-beta gene therapy inhibits orthotopic growth of human prostate cancer cells in nude mice. The purpose of this study was to determine efficacy and mechanisms of this therapy in immune-competent mice. TRAMP-C2Re3 mouse prostate cancer cells infected with 100 multiplicity of infection (MOI) of adenoviral vector encoding for mouse IFN-beta (AdmIFN-beta), but not AdE/1 (a control adenoviral vector), produced approximately 60 ng/10(5) cells/24 h of IFN-beta. The tumorigenicity of AdmIFN-beta-transduced cells was dramatically reduced in the prostates of C57BL/6 mice. A single intratumoral injection of 2 x 10(9) PFU (plaque-forming unit) of AdmIFN-beta inhibited tumor growth by 70% and prolonged survival of tumor-bearing mice. Intriguingly, this AdmIFN-beta therapy did not alter the growth of tumors in inducible nitric oxide synthase (iNOS)-null C57BL/6 mice. Immunohistochemical analysis revealed that treatment of tumors with AdmIFN-beta in wild-type C57BL/6 mice led to increased iNOS expression, decreased microvessel density, decreased cell proliferation, and increased apoptosis. Furthermore, quantitative reverse-transcriptional PCR analysis showed that AdmIFN-beta therapy, in C57BL/6 but not the iNOS-null counterparts, reduced levels of the mRNAs for angiopoietin, basic fibroblast growth factor, matrix metalloproteinase-9, transforming growth factor-beta1, vascular endothelial growth factor (VEGF)-A, and VEGF-B, as well as the antiapoptotic molecule endothelin-1. These data indicated that IFN-beta gene therapy could be effective alternative for the treatment of locally advanced prostate cancer and suggest an obligatory role of NO in IFN-beta antitumoral effects in vivo.
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PMID:Inducible nitric oxide synthase activity is essential for inhibition of prostatic tumor growth by interferon-beta gene therapy. 1647 Feb 11

Interferon (IFN)-beta is a multifunctional cytokine. Our previous studies revealed that intratumoral transfer of the murine interferon (IFN)-beta gene inhibited the growth of human and mouse prostate cancer cells in mice. Since IFN-beta activity is species-restricted, we investigated the efficacy and mechanisms of forced expression of human IFN-beta in suppressing the growth of human prostate cancer cells in mice. Orthotopic tumors of PC-3MM2 human prostate cancer cells were forced to express human IFN-beta by intratumoral injection of an adenoviral vector (AdhIFN-beta). Tumor growth and survival of tumor-bearing mice were determined. Cell proliferation and apoptosis were evaluated by immunohistochemistry (IHC) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Angiogenesis and angiogenic molecule expression were evaluated by IHC and quantitative real-time reverse-transcriptional PCR (qRT-PCR). We found that forced expression of human IFN-beta inhibited tumor growth in a dose-dependent manner. An injection of 2 x 10(9) PFU (plaque-forming units) of AdhIFN-beta retarded tumor growth by 90% and prolonged the survival of tumor-bearing mice. Control tumors contained more proliferating cells (PCNA(+)) and fewer apoptotic cells (TUNEL(+)) than did AdhIFN-beta treated-tumors. Treatment with AdhIFN-beta downregulated the expression of interleukin-8 and vascular endothelial cell growth factor-A. Taken together, our data indicated that forced expression of human IFN-beta in human prostate cancer cells significantly inhibited their prostatic growth, which correlated with downregulation of angiogenic molecules and suggested that adenoviral vector-mediated IFN-beta gene therapy could be an effective approach for the management of human prostate cancer.
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PMID:Adenovirus-mediated interferon-beta gene transfer inhibits angiogenesis in and progression of orthotopic tumors of human prostate cancer cells in nude mice. 1708 78

RNA-degradation is one of the fundamental mechanisms of interferon (IFN)-inducible antiviral response in mammalian cells. This is primarily brought about by the IFN-inducible 2',5'-oligoadenylate (2-5A)-cofactor dependent ribonuclease L (RNase L). RNase L also functions as a tumor suppressor gene in case of prostate cancer due to its role in apoptosis. We report that RNase L is induced by stress-inducing agents such as double-stranded RNA [poly(I:C)], chemotherapeutic drugs, hydrogen peroxide (H(2)O(2)), calcium chloride (CaCl(2)) and tumor necrosis factor-alpha (TNF) in the human cervical carcinoma (HeLa) cells. The level of RNase L was not detected in the untreated cells. Induction of RNase L by such stress-inducing agents correlated with degradation of cellular RNA, fragmentation of chromatin-DNA and induction of apoptosis. We checked the stress-inducible transcription factor, nuclear factor kappa B (NF-kappaB), which was persistently activated by cycloheximide but not by other agents after 24 hours indicating no role of NFkappaB in the RNase L-induction. However, as expected, TNF-induced NF-kappaB activity was stimulated within 10-30 minutes through degradation of IkappaB-alpha. Our results strongly suggest that the IFN-inducible RNase L is induced by a broad range of stress-inducing signals such as double-stranded RNA (dsRNA) produced during viral infection, membrane- and osmotic shock caused by CaCl(2) and oxidative stress induced by H(2)O(2), inflammation stimulated by TNF-alpha and chemotherapy. Thus, in addition to its antiviral function, the IFN-inducible RNase L may play an important role during stress-response through RNA-degradation and apoptosis.
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PMID:Induction of the interferon-inducible RNA-degrading enzyme, RNase L, by stress-inducing agents in the human cervical carcinoma cells. 1720 Jun 14

Targeting of human telomerase reverse transcriptase (hTERT) by different small interfering RNAs (siRNAs) resulted in a variable degree of telomerase activity inhibition in PC-3 and DU145 prostate cancer cells. In addition, transfection with siRNA5 and siRNA41, which caused high levels ( approximately 80 and approximately 55%, respectively) of enzyme activity inhibition in both cell lines, led to a marked reduction of hTERT mRNA and protein expression and a significant inhibition of cell proliferation within a few days, without concomitant telomere shortening or telomeric 3' overhang impairment. Such an antiproliferative effect was not ascribable to the activation of non-specific responses, since siRNA5 and siRNA41 did not induce the expression of 2'-5' oligoadenylate synthetase-1 and were able to cause a significant growth impairment also in HCT 116 colon cancer cells, which have a defective interferon pathway. Cell growth inhibition was indeed associated with hTERT down-regulation, as it was almost completely rescued in siRNA-treated HCT 116 cells co-transfected with an hTERT-expressing vector. Moreover, siRNA5 and siRNA41 failed to affect the proliferation of hTERT-negative U2-OS osteosarcoma cells. Interestingly, transfection with siRNA5 significantly reduced the tumorigenic and growth potential of PC-3 cells when xenotransplanted into nude mice. Such data suggest siRNA-mediated hTERT down-regulation as an efficient strategy to impair prostate cancer cell growth.
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PMID:Down-regulation of human telomerase reverse transcriptase through specific activation of RNAi pathway quickly results in cancer cell growth impairment. 1732 2

Interferon-inducible IFI16 protein (encoded by IFI16 gene located at 1q21 region) is a member of the p200-protein family. The family includes structurally and functionally-related mouse (for example, p202, p203, and p204 proteins) and human (for example, MNDA, AIM2, and IFIX) proteins. Increased expression of p200-family proteins in a variety of cells is known to inhibit cell cycle progression and modulate cell survival. Consistent with this role of p200-family proteins, increased expression of IFI16 protein in normal human diploid fibroblasts and prostate epithelial cells is associated with cellular senescence-associated permanent cell growth arrest. Furthermore, reduced or loss of IFI16 expression in cells is associated with the development of certain cancers, such as breast and prostate cancer. Interestingly, recent studies have provided evidence that the constitutive and interferon-induced expression of the IFI16 gene varies among individuals and may depend on the race. These studies raise the possibility that alterations (increases or decreases) in the expression of IFI16 protein may contribute to the development of human diseases. In this review, we discuss how our understanding of the regulation of IFI16 expression and its role in cell growth regulation will help elucidate the molecular mechanisms that contribute to the development of various human diseases.
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PMID:Interferon-inducible IFI16 protein in human cancers and autoimmune diseases. 1798 73

Toll-like receptors (TLRs) are known to play a key role in the innate immune system particularly in inflammatory response against invading pathogens. Recent reports strongly indicate that they play important roles in cancer cells. Prostate cancer represents one of the most common cancer for which no cure is available once metastatic and androgen refractory. Since TLR3 has been recently suggested as a possible therapeutic target in some cancer cell lines, we studied TLR3 expression and functionality in two human prostate cancer cell lines, LNCaP and PC3. We report that both cell lines express TLR3 and that the TLR3 agonist poly (I:C) activates mitogen-activated protein kinases and induces inhibition of proliferation as well as caspase-dependent apoptosis. By using pharmacological and genetic approaches, we demonstrate the involvement of TLR3 in poly (I:C)-induced effects. We also show that a novel interferon-independent pathway involving protein kinase C (PKC)-alpha activation, upstream of p38 and c-jun N-terminal kinase, is responsible for poly (I:C) pro-apoptotic effects on LNCaP cells. To our knowledge, this is the first report describing a role of PKC-alpha in poly (I:C)-mediated apoptosis. The comprehension of the mechanisms underlying TLR3-mediated apoptosis can contribute tools to develop new agonists useful for the treatment of prostate cancer.
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PMID:Toll-like receptor 3 triggers apoptosis of human prostate cancer cells through a PKC-alpha-dependent mechanism. 1856 14

Cell-based therapy for cancer is a promising new field. Among cell types that can be used for this purpose, mesenchymal stem cells (MSCs) appear to hold great advantage for reasons including easier propagation in culture, possible genetic modification to express therapeutic proteins and preferential homing to sites of cancer growth upon in vivo transfer. The present study evaluated the potential of genetically modified MSC, constitutively expressing interferon (IFN)-beta, in an immunocompetent mouse model of prostate cancer lung metastasis. A recombinant adeno-associated virus (rAAV) encoding mouse IFN-beta was constructed and initially tested in vitro for high-level expression and bioactivity of the transgenic protein. MSCs were transduced by the rAAV-IFN-beta or green fluorescent protein ex vivo and used as cellular vehicles to target lung metastasis of TRAMP-C2 prostate cancer cells in a therapy model. Cohorts of mice were killed on days 30 and 75 to determine the effect of therapy by measurement of tumor volume, histology, immunohistochemistry, enzyme-linked immunosorbent assay and flow cytometry. Results indicated a significant reduction in tumor volume in lungs following IFN-beta-expressing MSC therapy. Immunohistochemistry of the lung demonstrated increased tumor cell apoptosis and decreased tumor cell proliferation and blood vessel counts. A significant increase in the natural kill cell activity was observed following IFN-beta therapy correlating the antitumor effect. Systemic level of IFN-beta was not significantly elevated from this targeted cell therapy. These data demonstrate the potential of MSC-based IFN-beta therapy for prostate cancer lung metastasis.
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PMID:Cancer gene therapy using mesenchymal stem cells expressing interferon-beta in a mouse prostate cancer lung metastasis model. 1859 29


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