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)

Activation of cell surface components has been implicated in the activation of downstream signaling cascade in response to UV irradiation, and yet the identity and the interaction of those components have been scantly documented. Accumulating evidence indicates that caveolae encapsulating caveolins is the location for those interactions. We found in cultured human keratinocytes that UV irradiation induced both caveolin-1 and EGFR phosphorylation. Filipin, a caveolae disruptive agent, inhibited UV-induced caveolin-1 activation. Na+-K+-ATPase catalyzes active transport of Na+ and K+ across plasma membrane of mammalian cells, inactivation of which has recently been shown to be involved in the activation of signal transduction pathways including MAP kinase cascade. We found in this study that UV inactivated Na+-K+-ATPase in time-dependent manner, Na+-K+-ATPase activity started to decrease 5 min post UV irradiation and reduced to 60% of its original activity within 1 h. Pretreatment with Flipin and MMP inhibitor recovered Na+-K+-ATPase activity lost by UV irradiation. ECIS analysis indicated that both EGF treatment and UV irradiation increased membrane electric activity which was inhibited by MMP inhibitor and Filipin. Further study showed that pretreatment of human keratinocytes with MMP inhibitor or Filipin inhibited UV-induced phosphorylation of p38 and JNK, which was however not observed in LnCap cells, a prostate cancer cell line lacking caveolin-1. UV irradiation also induced ectodomain shedding of HB-EGF in a time-dependent manner in keratinocytes. Collectively, we conclude that UV-induced MAP kinase activation is mediated by cell surface receptor activation due to the matrix activity and membrane caveolae function and inactivation of Na+-K+-ATPase.
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PMID:Extracellular matrix activity and caveolae events contribute to cell surface receptor activation that leads to MAP kinase activation in response to UV irradiation in cultured human keratinocytes. 1575 25

Caveolin-1 (Cav-1) is the primary structural component of caveolae and is implicated in the processes of vesicular transport, cholesterol balance, transformation, and tumorigenesis. Despite an abundance of data suggesting that Cav-1 has transformation suppressor properties both in vitro and in vivo, Cav-1 is expressed at increased levels in human prostate cancer. To investigate the role of Cav-1 in prostate cancer onset and progression, we interbred Cav-1(-/-) null mice with a TRAMP (transgenic adenocarcinoma of mouse prostate) model that spontaneously develops advanced prostate cancer and metastatic disease. We found that, although the loss of Cav-1 did not affect the appearance of minimally invasive prostate cancer, its absence significantly impeded progression to highly invasive and metastatic disease. Inactivation of one (+/-) or both (-/-) alleles of Cav-1 resulted in significant reductions in prostate tumor burden, as well as decreases in regional lymph node metastases. Moreover, further examination revealed decreased metastasis to distant organs, such as the lungs, in TRAMP/Cav-1(-/-) mice. Utilizing prostate carcinoma cell lines (C1, C2, and C3) derived from TRAMP tumors, we also showed a positive correlation between Cav-1 expression and the ability of these cells to form tumors in vivo. Furthermore, down-regulation of Cav-1 expression in these cells, using a small interfering RNA approach, significantly reduced their tumorigenic and metastatic potential. Mechanistically, we showed that loss or down-regulation of Cav-1 expression results in increased apoptosis, with increased prostate apoptosis response factor-4 and PTEN levels in Cav-1(-/-) null prostate tumors. Our current findings provide the first in vivo molecular genetic evidence that Cav-1 does indeed function as a tumor promoter during prostate carcinogenesis, rather than as a tumor suppressor.
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PMID:Caveolin-1 promotes tumor progression in an autochthonous mouse model of prostate cancer: genetic ablation of Cav-1 delays advanced prostate tumor development in tramp mice. 1580 73

Phorbol 12-myristate 13-acetate (PMA)-induced apoptosis of androgen sensitive LNCaP human prostate cancer cells is a well known phenomenon that involves prolonged translocation of multiple protein kinase C (PKC) isozymes to nonnuclear membranes. We have shown recently that PMA-induced death of C4-2 cells, androgen hypersensitive derivatives of LNCaP cells, requires both PKCdelta and a redundant pathway that includes PKCs alpha and epsilon. In contrast, it has been reported that overexpression of murine PKCepsilon in LNCaP cells renders those cells resistant to PMA-induced death, as well as androgen insensitive. Here we report that inducible or constitutive overexpression of human PKCepsilon does not alter the sensitivity of LNCaP cells to either PMA or androgen, nor does it alter expression of caveolin-1 or phosphorylated Rb, reported effects of overexpression of murine PKCepsilon. Moreover, overexpression of very high amounts of PKCepsilon sensitized LNCaP cells to induction of apoptosis by bryostatin 1, a non tumor-promoting activator and down-regulator of PKC isozymes that blocks PMA-induced apoptosis of parental LNCaP cells, mimicked our previous results with overexpression of PKCalpha in LNCaP cells. Given reports that overexpression of PKCepsilon is frequent in human prostate tumors, our results may have important implications for a potential prostate cancer therapy.
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PMID:Overexpression of PKCepsilon sensitizes LNCaP human prostate cancer cells to induction of apoptosis by bryostatin 1. 1618 49

Novel approaches for the early detection of urogenital cancers are urgently needed. Metastatic renal cell carcinoma (RCC) has a poor prognosis and unpredictable course and to date there are no molecular markers that reliably protect RCC outcome. A novel kidney cancer marker, carbonic anhydrase IX (CA IX), was investigated as an independent prognostic factor for survival for patients with metastatic RCC. In patients with non-metastatic RCC low CAIX predicted a worse outcome similar to patients with metastatic disease and overall CAIX expression decreased with development of metastasis. CAIX reflects significant changes in tumour biology, which may be used to predict clinical outcome and identify high-risk patients for adjuvant-targeted therapies. With regard to prostate cancer there are a number of putative biomarkers, although there are limited studies providing clinical correlations in humans. Potential biomarkers include caveolin-1, p-Akt, p27, the met oncogene, Ki67 (MIB-1), 8q24 over-expression, polycomb protein EZH2, plasma TGF-B1 and IL-6 among others. The laboratory has concentrated on the Prostate Stem Cell Antigen (PSCA) which is increased in patients with more aggressive features, that is higher Gleason grade and higher stage. Highest expression is seen in metastatic lesions to bone and staining for PSCA may predict for disease progression or recurrence. Also promising is the finding reported by the group that expression of p27 in radical prostatectomy specimens correlates with biochemical recurrence. Loss of p27 (defined as absent expression in more than 70% of the specimen) is an independent predictor of recurrence among all patients and among the sub-set with organ confined and extra-capsular disease. The data also shows that p27 can predict outcome among patients with positive surgical resection margins. As with other biomarkers, major questions still to be addressed is the requirement for universal application with uniform scoring and the need for prospective studies in randomized clinical trials.
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PMID:Biomarker discovery in urogenital cancer. 1629 16

Caveolin-1 (cav-1) is a major scaffolding component of cell membrane invaginations (caveolae). It is involved in sequestering numerous effectors and signaling molecules and has antiapototic activities in prostate cancer. Perineural invasion (PNI) is associated with decreased apoptosis of cancer cells both in human tissues and the in vitro PNI model. We show here that stromal (perineurium) production of cav-1 is involved in a paracrine antiapoptotic loop in PNI. Transforming growth factor-beta1 is up-regulated in the cancer cells as they approach the nerve and is thought to up-regulate cav-1 in the perineurium of nerves with prostate cancer. Cav-1 is then secreted into the microenvironment and used by prostate cancer cells to inhibit apoptosis. In the in vitro PNI model, this phenomenon is partially reversed by neutralizing cav-1 antibodies or using ganglia from cav-1 knockout mice. Our results show a novel paracrine mechanism used by the prostate cancer in PNI to increase their proliferative activity and decrease apoptosis.
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PMID:Stromal antiapoptotic paracrine loop in perineural invasion of prostatic carcinoma. 1670 39

Prostate-specific membrane antigen (PSMA) is a transmembrane protein with a highly restricted profile of expression. Expression is primarily limited to secretory cells of the prostatic epithelium, with elevated levels observed in prostate cancer. As an integral membrane protein correlated with prostate cancer, PSMA offers a potentially valuable target for immunotherapy. PSMA is also detected in the neovasculature of a variety of solid tumors but not in the endothelial cells of preexisting blood vessels. Although the significance of PSMA expression in these cells remains elusive, this pattern of expression implies that PSMA may perform a functional role in angiogenesis and may offer a therapeutic target for the treatment of a broad spectrum of solid tumors. In this study, we have expressed PSMA in human microvascular endothelial cells and demonstrate that PSMA binds to caveolin-1 and undergoes internalization via a caveolae-dependent mechanism. The association between PSMA and caveolae in endothelial cells may provide important insight into PSMA function and ways to best exploit this protein for therapeutic benefit.
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PMID:Association of prostate-specific membrane antigen with caveolin-1 and its caveolae-dependent internalization in microvascular endothelial cells: implications for targeting to tumor vasculature. 1671 5

1,1-bis(3'-indolyl)-1-(p-substitutedphenyl)methanes (C-DIMs) containing para-trifluoromethyl, t-butyl, and phenyl groups are a novel class of peroxisome proliferator-activated receptor (PPAR)gamma agonists. In LNCaP prostate cancer cells, these compounds induce PPARgamma-dependent transactivation, inhibit cell proliferation, and induce apoptosis. In addition, these PPARgamma agonists modulate a number of antiproliferative and proapoptotic responses, including induction of p27, activating transcription factor 3, and nonsteroidal anti-inflammatory drug-activated gene-1 and down-regulation of cyclin D1 and caveolin-1. Moreover, the PPARgamma antagonist 2-chloro-5-nitrobenzanilide (GW9662) does not inhibit these effects. The C-DIM compounds also abrogate androgen receptor (AR)-mediated signaling and decrease prostate-specific antigen (PSA) and AR protein expression, and these responses were PPARgamma-independent. The effects of C-DIMs on AR and PSA were due to decreased AR and PSA mRNA expression in LNCaP cells. Thus, this series of methylene-substituted diindolylmethane derivatives simultaneously activate multiple pathways in LNCaP cells, including ablation of androgen-responsiveness and down-regulation of caveolin-1. Both of these responses are associated with activation of proapoptotic pathways in this cell line.
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PMID:1,1-bis(3'-indolyl)-1-(p-substitutedphenyl)methanes inhibit growth, induce apoptosis, and decrease the androgen receptor in LNCaP prostate cancer cells through peroxisome proliferator-activated receptor gamma-independent pathways. 1709 36

Although androgens and the androgen receptor (AR) are involved in tumorigenesis of prostate cancer (PC) in initial phases, less clear is the role played in advanced androgen-independent (AI) stages of the disease. Several recent reports indicated that re-expression of AR in PC-derived cell lines determines a less aggressive phenotype of the cells. We have previously demonstrated that re-expression of AR decreases the invasion ability of PC3 cells in vitro by affecting signalling and internalization processes of epidermal growth factor receptor (EGFR). Here, we show that reduced EGFR internalization is also a characteristic of AR positive PC cell lines LNCaP and 22Rv1. Reduced internalization in PC3-AR cells is associated to a defective interaction between the EGFR and two adaptor proteins which mediate the endocytotic process, Grb2 and c-Cbl. As a consequence of such reduced interaction, ubiquitination of the receptor, which is mainly mediated by c-Cbl, is also altered. In addition, we show that internalized EGFR co-localizes with early endosome antigen-1, a marker of clathrin-mediated endocytosis, in PC3-Neo cells but not in AR positive cell lines. Conversely, EGFR maintains co-localization with caveolin-1 after EGF stimulation in PC3-AR cells. These data suggest that expression of AR affects clathrin-mediated endocytosis pathway of EGFR, which, according to recent findings, plays an essential role in the completeness of signalling of the receptor. Taken together, these data emphasize the role of AR in the regulation of EGFR endocytotic trafficking and active signalling in PC cells. In view of the role of EGFR signalling in invasion of carcinoma cells, our data may explain the lower invasive phenotype observed in AR-positive cell lines.
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PMID:Altered endocytosis of epidermal growth factor receptor in androgen receptor positive prostate cancer cell lines. 1724 69

Up-regulation of caveolin-1 (cav-1) has been implicated in human prostate cancer progression/metastasis and shown to promote cancer cell survival. It has also been shown that cav-1 is secreted by tumor cells and may regulate the growth, functional activities, and migration of vascular endothelial cells. However, the relationship of cav-1 expression in prostate cancer cells and tumor associated endothelial cells (TAEC) to tumor-associated angiogenesis remains to be investigated. Dual immunofluorescent labeling with antibodies to CD34 and cav-1 was performed on 56 prostate cancer specimens obtained by radical prostatectomy and stratified according to cav-1 positivity in cancer cells. The tumor microvessel densities (MVD) and cav-1 expression in TAEC within these specimens were measured and correlated with cav-1 expression in prostate cancer cells. The MVD values were significantly higher in cav-1-positive (n = 25) than in the cav-1-negative (n = 31) tumors (median of 44 versus 25 vessels/field, P = .0140). Additional studies showed that the cav-1 positivity in microvessels within tumor specimens was significantly less frequent than in the blood vessels of benign prostatic tissues (94.4% versus 98.6%, P = .0012). In contrast, the percentage of cav-1-positive TAEC in cav-1-positive tumors was significantly higher than in cav-1-negative tumors (95.8% versus 92.7%, P = .0024). This increased cav-1 positivity in TAEC was predominantly confined to regions with cav-1-positive tumor cells corresponding to the higher percentage of cav-1-positive microvessels within these regions in cav-1-positive, as opposed to cav-1-negative tumors (P = .0086). These positive correlations provide new evidence for the involvement of prostate cancer cell derived cav-1 in mediating angiogenesis during prostate cancer progression. They also establish a conceptual framework for further investigation of cav-1 proangiogenic activities.
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PMID:Correlative evidence that prostate cancer cell-derived caveolin-1 mediates angiogenesis. 1826 34

Prostate cancer is the second leading cause of cancer-related deaths in men. Fatty acid synthase (FASN) is normally upregulated during human prostate cancer onset and metastatic progression and its expression positively correlates with the development of advanced metastatic disease. However, it remains unknown what molecular factor(s) control FASN expression. It has been hypothesized that FASN functions as a tumor promoter during prostate cancer progression in humans. Consistently, an established mouse of model of prostate cancer, termed TRAMP mice, also shows the progressive upregulation of FASN levels during prostate cancer development. Here, we examine the role of caveolin-1 (Cav-1) in regulating FASN expression during prostate cancer progression. For this purpose, we crossed Cav-1-/- null mice with TRAMP mice to generate TRAMP/Cav-1+/+ and TRAMP/Cav-1-/- mice. Then, we assessed the expression of FASN in Cav-1+/+ and Cav-1-/- prostate tumors by immuno-histochemistry and Western blot analysis. Interestingly, our results indicate that FASN fails to be upregulated in Cav-1-/- tumors. Importantly, the tumors examined were the same morphological grade, but Cav-1-/- tumors were dramatically smaller and did not metastasize efficiently. We conclude that Cav-1 expression is normally required for the upregulation of FASN during prostate cancer progression. These results also mechanistically explain why TRAMP/Cav-1-/- mice are dramatically resistant to the development of prostate tumors and lung metastases, as they lack the expression of the FASN tumor promoter. Thus, TRAMP/Cav-1-/- mice will provide a novel model system to elucidate the role of FASN in prostate tumor progression. In addition, our results provide the first molecular genetic evidence that Cav-1 functions upstream of FASN during prostate cancer progression.
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PMID:Caveolin-1 is required for the upregulation of fatty acid synthase (FASN), a tumor promoter, during prostate cancer progression. 1778 30


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