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)

Although several epidemiologic studies show an association between arsenic exposure and prostate cancer, it is still unknown whether human prostate epithelial cells are directly susceptible to arsenic-induced transformation. This study was designed to determine whether the nontumorigenic human prostate epithelial cell line RWPE-1 could be malignantly transformed in vitro by arsenite. RWPE-1 cells were continuously exposed to 5 micro M arsenite and monitored for signs of transformation, assessed as changes in matrix metalloproteinase-9 levels. After 29 weeks of exposure, the arsenite-exposed RWPE-1 cells (referred to as CAsE-PE) showed a marked increase in matrix metalloproteinase-9 secretion, a common finding in prostate malignancies. Malignant transformation was confirmed when CAsE-PE cells produced aggressive undifferentiated malignant epithelial tumors in nude mice. The tumors stained positive for human prostate-specific antigen, confirming their origin. These results are the first report of arsenite-induced malignant transformation of a human epithelial cell line and provide an important in vitro model for studying the mechanisms underlying arsenic-induced carcinogenesis in humans.
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PMID:Inorganic arsenite-induced malignant transformation of human prostate epithelial cells. 1248 83

Metastasis of prostate cancer to bone is a common complication of progressive prostate cancer. Skeletal metastases are often associated with severe pain and thus demand therapeutic interventions. Although often characterized as osteoblastic, prostate cancer skeletal metastases usually have an underlying osteoclastic component. Advances in osteoclast biology and pathophysiology have led toward defining putative therapeutic targets to attack tumor-induced osteolysis. Several factors have been found to be important in tumor-induced promotion of osteoclast activity. One key factor is the protein receptor activator of nuclear factor-kappa B ligand (RANKL), which is required to induce osteoclastogenesis. RANKL is produced by prostate cancer bone metastases, enabling these metastases to induce osteolysis through osteoclast activation. Another factor, osteoprotegerin, is a soluble decoy receptor for RANKL and inhibits RANKL-induced osteoclastogenesis. Osteoprotegerin has been shown in murine models to inhibit tumor-induced osteolysis. In addition to RANKL, parathyroid hormone-related protein and interleukin-6 are produced by prostate cancer cells and can promote osteoclastogenesis. Finally, matrix metalloproteinases (MMPs) are secreted by prostate cancer cells and promote osteolysis primarily through degradation of the nonmineralized bone matrix. MMP inhibitors have been shown to diminish tumor establishment in bone in murine models. Thus, many factors derived from prostate cancer metastases can promote osteolysis, and these factors may serve as therapeutic targets. The importance of osteoclasts in the establishment and progression of skeletal metastases has led to clinical evaluation of therapeutic agents to target them for slowing metastatic progression. Bisphosphonates are a class of compounds that decrease osteoclast life span by promoting their apoptosis. The bisphosphonate pamidronate has proven clinical efficacy for relieving bone pain associated with breast cancer metastases and has a promising outlook for prostate cancer metastases. Another bisphosphonate, zoledronic acid, appears to directly target prostate cancer cells in addition to diminishing osteoclast activity at the metastatic site. In addition to bisphosphonates, other novel therapies based on studies that delineate mechanisms of skeletal metastases establishment and progression will be developed in the near future.
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PMID:The role of osteoclastic activity in prostate cancer skeletal metastases. 1253 87

Epithelial cancer cell invasion is facilitated by stromal cells, immune cells, endothelial cells and other epithelial cells. We have used two human papilloma immortalized prostate cell lines, CA-HPV-10 from a carcinoma and PZ-HPV-7 cells from normal prostatic epithelium to study cell-cell influences on growth, gelatinase secretion, invasion and responses to TGFbeta1. We found that co-culture with CA-10 carcinoma cells stimulates proliferation of the PZ-7 epithelial line. TGFbeta1 inhibited growth of both lines, but while inhibitory effects on the CA-10 cells diminished after removal of the peptide, inhibition of PZ-7 was lasting. Interestingly, the TGFbeta-induced growth inhibition in PZ-7 cells could be partially reversed by co-culture with CA-10 cells. Co-culture with CA cells in a 3-chamber invasion assay also promoted invasion of PZ cells. CA-10 invasion was enhanced by co-culture with TGFbeta1-treated-PZ-7 cultures and this enhancement was associated with TGFbeta1-induced secretion of matrix metalloproteinase-9. Our observations suggest that interaction between prostate cancer cells and prostate epithelial cells may promote proliferation of the epithelial cell population and produce a paracrine source of MMP-9 which may facilitate early cancer cell invasion.
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PMID:Paracrine communication between malignant and non-malignant prostate epithelial cells in culture alters growth rate, matrix protease secretion and in vitro invasion. 1255 79

The purpose of this study was to determine the effects of inhibitors of Rho kinase (ROK) and matrix metalloproteinases (MMPs) on angiogenesis and tumor growth and to evaluate ROK activity in human prostate cancer PC3 cells and endothelial cells (HUVECs). Vacuolation by endothelial cells and lumen formation, the earliest detectable stages of angiogenesis, were inhibited by the ROK inhibitor Wf-536. Combining Wf-536 with the MMP inhibitor Marimastat greatly enhanced in vitro inhibition of endothelial vacuolation, lumen and cord formation, and VEGF- and HGF-stimulated endothelial sprout formation from aorta. Inhibition of sprout formation by the two inhibitors was synergistic. Both agents inhibited migration of HUVECs. The regulatory subunit (MYPT1) of the myosin phosphatase was phosphorylated in PC3 cells and HUVECs, and phosphorylation of MYPT1 and the myosin regulatory light chain was reduced by Wf-536, providing direct evidence of ROK activity. Early treatment of immuno-incompetent mice bearing xenotransplants of PC3 cells with a combination of Wf-536 plus Marimastat with or without Paclitaxel, significantly inhibited tumor growth, prevented tumor growth escape after discontinuation of Paclitaxel, and increased survival.
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PMID:Rho kinase and matrix metalloproteinase inhibitors cooperate to inhibit angiogenesis and growth of human prostate cancer xenotransplants. 1255 1

Stromal expression of some matrix metalloproteinases (MMPs) has been associated with increasing tumour burden in prostate cancer. We investigated the expression of mRNA (by RT-PCR) and protein (by zymography and western blotting) of MMPs and endogenous inhibitors (tissue inhibitors of metalloproteinases, TIMPs) in two parent epithelial prostate cancer cell lines and sublines of increasing invasive/metastatic potential. Expression of membrane type MMPs, MT1-MMP and MT3-MMP mRNA was higher in PC3-derived than in LNCaP-derived lines, whereas MT2-MMP mRNA expression was higher in the LNCaPderived than in PC3-derived cell lines. Active MT1, MT2 and MT3-MMP protein levels were similar in all lines, but processed MT-MMPs, indicative of latent MMP activation, were increased in more aggressive sublines. Expression of MMP-1, MMP-13 and TIMP-1 was higher in the more aggressive sublines and may be implicated in invasive/metastatic ability. Regulation of MMP-1 and MMP-13 expression may offer important therapeutic options for treating patients with prostate cancer.
Prostate Cancer Prostatic Dis 2003
PMID:Characterization of expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in prostate cancer cell lines. 1266 60

Degradation of the extracellular matrix by proteolytic enzymes is a central aspect of physiological and pathologic tissue-remodeling processes such as trophoblastic implantation, wound healing, and tumor invasion. We have hypothesized that prostate adenocarcinoma cell invasion through the normal basal lamina is attributable in part to metalloproteinase-induced cleavage of laminin-5 (Ln-5) and enhanced motility of the cancer cells. We studied the role of membrane type-1-matrix metalloproteinase (MT1-MMP) expressed on the surface of prostate tumor cells in cleaving Ln-5 and enhancing the migration of prostate tumor cells. We also determined the nature of the MT1-MMP cleavage of human Ln-5 and how this altered Ln-5 changes the migration of prostate carcinoma cells. We found that human MT1-MMP cleaves purified human Ln-5 to an 80-kDa fragment. Mass spectrometry analyses of the 80-kDa cleaved product by trypsin and chymotrypsin gave 14 and 9 different peptide sequences, respectively, that were identical to the expected amino acid sequence of the Ln-5-beta3 chain. The recovered peptides represent 14.4% (trypsin) and 10.3% (chymotrypsin) of Ln-5-beta3 chain by amino acid count. Both trypsin and chymotrypsin digestion of MT1-MMP-cleaved product of Ln-5 did not show any other peptides that were identical to the other chains of Ln-5. Using a linear migration assay we found that the Ln-5 cleaved by MT1-MMP enhanced the migration of DU-145 prostate carcinoma cells by 2-fold compared with uncleaved Ln-5. The use of blocked antisense MT1-MMP oligonucleotides inhibited the migration of DU-145 cells on Ln-5. We also found that the prostate carcinoma cells expressing high levels of MT1-MMP, such as PC3N and PPC, demonstrated enhanced migration on human Ln-5-coated substrate, and this migration was inhibited using blocked antisense MT1-MMP oligonucleotides. In conclusion, this is a novel and important finding where we have shown that beta3-chain is cleaved by MT1-MMP, and this cleavage enhances migration of prostate cancer cells.
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PMID:Membrane type-1-matrix metalloproteinase expressed by prostate carcinoma cells cleaves human laminin-5 beta3 chain and induces cell migration. 1272 52

Angiogenesis was postulated to be a critical prognostic factor and therapeutic focus for malignancy more than two decades ago. Recent studies indicate quantitative assessments of microvessel count to be an independent prognostic variable for disease-free and overall survival in a wide variety of tumors, and that angiogenesis may be a feasible target against which to intervene pharmacologically. Several new and old agents have been found to have anti-angiogenic activity and have reached clinical trial. This review will focus on four agents under investigation in the US: carboxyamido-triazole (CAI), thalidomide, TNP-470 and interleukin (IL)-12. CAI, originally identified for its anti-invasive capacity, has been shown to inhibit tumor and endothelial cell proliferation by inhibition of calcium uptake. It is administered orally, is generally well tolerated, and has been shown to induce disease stabilization and occasional reductions in tumor mass. Thalidomide was shown to inhibit growth factor-induced neovessel formation, a process that can also explain its earlier devastating clinical toxicity. It is administered orally, and is currently in phase II clinical trials for prostate cancer, glioblastoma multiforme and breast cancer. TNP-470 is a fumagillin analog that has been shown in in vivo models to be a potent inhibitor of angiogenesis at concentrations that are cytostatic to endothelial cells and tumor cells. Lastly, IL-12 may exert its anti-angiogenic effects through activation of interferon-gamma to up-regulate interferon-inducible protein-10, an anti-angiogenic cytokine. Phase I clinical trials of IL-12 have shown disease stabilization in several tumor types in response to s.c. administration or using genetically engineered IL-12-expressing patient fibroblasts. These promising new agents join the matrix metalloproteinase inhibitors as important new drugs in the anti-cancer armamentarium.
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PMID:New anti-angiogenesis agents: review of the clinical experience with carboxyamido-triazole (CAI), thalidomide, TNP-470 and interleukin-12. 1451 90

The tetracycline family includes tetracycline, doxycycline and minocycline, all of which have been used as antibiotics effectively for decades. New uses emerged for these compounds after their effect on mitochondrial function was discovered. Cytostatic and cytotoxic activity of these compounds was shown against cell lines of various tumor origins. In addition, tetracyclines and chemically modified tetracyclines inhibit the activity of several matrix metalloproteinases (MMPs). Given the importance of these enzymes in tumor cell invasion and metastatic ability, the potential use of tetracyclines in cancer therapy needed to be investigated. Col-3, a chemically modified tetracycline, is now the subject of clinical trials in cancer patients. However, the potential of tetracyclines in cancer therapy takes on an added dimension in the bone. MMPs have been shown to be important mediators of metastasis formation in the bone, contributing largely to the morbidity of breast cancer and prostate cancer patients. The natural osteotropism of tetracyclines would allow them to be highly effective in the inhibition of MMPs produced by osteoclasts or tumor cells in the bone. This hypothesis has now been confirmed by experimental evidence showing that doxycycline reduces tumor burden in a mouse model of breast cancer-derived osteolytic bone metastasis. This effect is likely due to a combination of multiple roles of doxycycline, including MMP inhibition and a negative effect on osteoclast differentiation and survival. These encouraging results have now paved the way for an ongoing trial of doxycycline in early combination therapy for breast cancer and prostate cancer patients.
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PMID:Doxycycline and other tetracyclines in the treatment of bone metastasis. 1459 70

Tissue inhibitors of metalloproteinases (TIMPs) have been shown to perform several biological functions in tumor promotion, principally by their action of inhibiting matrix metalloproteinases (MMPs) at different steps of the metastatic process. In particular, TIMP-2 is involved in a functional complex with the membrane-type 1 (MT1) MMP to convert the secreted MMP-2 progelatinase into the fully active proteolytic enzyme. We used the human, androgen-sensitive prostate carcinoma cell line LNCaP in coculture with the human osteosarcoma cell line OHS to experimentally address the possibility of androgen-dependent regulatory effects on the functional MT1-MMP/TIMP-2/MMP-2 complex upon interaction between prostate carcinoma and osteoblastic cells in metastasis of prostate cancer to bone. In the LNCaP cells a gradual, time-dependent decline in TIMP-2 mRNA expression was observed in the presence of the synthetic androgen analogue R1881 (100 nM), reaching approximately 25% of the control level after 48 h of incubation. Consistent with this, the accumulation of secreted TIMP-2 in media from R1881-treated cells was significantly inhibited already after 3 h. Neither MMP-2 gelatinolytic activity nor expression of MT1-MMP was detected in LNCaP cells. In contrast, the OHS cells showed membrane-associated MT1-MMP expression as well as MMP-2 secretion. However, R1881 treatment of the LNCaP/OHS coculture model did not seem to change the overall proteolytic activity of the MT1 -MMP/TIMP-2/MMP-2 complex. Hormonal control of TIMP-2 expression in prostate carcinoma cells has not been previously reported, but whether such regulation has any functional role in the development of osteoblastic metastases in prostate cancer is still unclear.
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PMID:The metalloproteinase inhibitor TIMP-2 is down-regulated by androgens in LNCaP prostate carcinoma cells. 1459 88

We investigated expression of gamma-aminobutyric acid (GABA), glutamate decarboxylase, and matrix metalloproteinase (MMP) in the prostates of patients with cancer or benign prostatic hypertrophy by immunohistochemical study. Marked expression of GABA, glutamate decarboxylase 67, and MMPs was observed in the prostates of cancer patients with metastasis (n = 72) and lymph node metastasis, although only sparse expression was noted in those of cancer patients without metastasis (n = 76) or patients with benign prostatic hypertrophy (n = 152). We then investigated the influence of GABA stimulation on in vitro MMP production and the invasive ability of cancer cells using human prostate cancer cell line C4-2. The production of MMPs increased significantly in cancer cells after a 24-h incubation with GABA. Cell invasion assay using a BioCoat Matrigel Invasion Chamber kit revealed that GABA stimulation significantly promoted the invasive ability of cancer cells and that addition of MMP inhibitor GM6001 significantly decreased GABA-induced migration. This may indicate the involvement of MMP activity in GABA-induced cancer cell invasion. We further analyzed the transmission pathway by performing GABA receptor modulation. The GABA(B) receptor agonist baclofen significantly increased MMP production as well as invasive ability. Moreover, blockade of the GABA(B) receptor pathway using GABA(B) receptor antagonist CGP 35348 significantly inhibited GABA-induced MMP production and invasive ability in cancer cells, whereas GABA(A) receptor modulation did not influence MMP production or the invasive ability of cancer cells. Thus, increased expression of GABA may be implicated in cancer metastasis by promoting MMP production in cancer cells, and the GABA(B) receptor pathway may be involved in the process.
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PMID:Gamma-aminobutyric acid as a promoting factor of cancer metastasis; induction of matrix metalloproteinase production is potentially its underlying mechanism. 1467 58


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