Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153690 (bone metastases)
 6,382 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Demineralized extracts of bone matrix and conditioned media from cultured fetal rat calvaria have been reported to contain growth stimulatory activity for bone cells. To investigate the potential role of these local bone growth factors in the development of bone metastases, we chose the Walker 256 carcinosarcoma, a rat mammary tumor which causes osteolytic bone metastases and hypercalcemia. 45Ca-labeled, 19-day fetal Sprague-Dawley rat calvaria were cultured for 96 hours in BGJb medium. Walker cells from ascites tumors or cultures were grown in unconditioned media or in conditioned media harvested from the bone cultures, in the presence of 10% fetal calf serum. Media were changed every 2 days, cells were counted daily for 5 days, and 3H-thymidine uptake into acid insoluble residues was measured. The growth of tumor cells was 5-6-fold greater in conditioned media than in unconditioned media and the effect was dose dependent. Cells cultured in conditioned media demonstrated a approximately 3-fold enhancement of 3H-thymidine incorporation. Generation of growth stimulatory activity correlated with the extent of bone resorption, measured by release of 45Ca from the fetal parietal bones (r = 0.85; P less than 0.001). Conditioned media from bones cultured with 10(-7) M prostaglandin E2 (PGE2) contained greater amounts of growth stimulatory activity than untreated conditioned media, but PGE2 itself did not stimulate tumor cell growth. Addition of 3.5 mM PO4 to bone cultures blocked bone resorption and the generation of growth factors. Growth stimulatory activity was stable to heat (56 C for 30 minutes) and trypsin digestion, with an apparent molecular weight of less than 17,000 daltons by high-performance liquid chromatography. Conditioned medium also stimulated the growth of 13762 rat mammary adenocarcinoma cells, MB-MDA-231 human breast carcinoma cells, TE-85 osteosarcoma cells, a murine fibrosarcoma and rat embryonic fibroblasts, with the most potent effects noted for Walker tumor cells, the TE-85 osteosarcoma, and human breast carcinoma lines. These results suggest a mechanism by which bone resorption could promote the development of skeletal metastasis.
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PMID:Resorbing bone stimulates tumor cell growth. A role for the host microenvironment in bone metastasis. 345 36

Kallikrein-related peptidase 4 (KLK4) is one of the 15 members of the human KLK family and a trypsin-like, prostate cancer-associated serine protease. Signaling initiated by trypsin-like serine proteases are transduced across the plasma membrane primarily by members of the protease-activated receptor (PAR) family of G protein-coupled receptors. Here we show, using Ca(2+) flux assays, that KLK4 signals via both PAR-1 and PAR-2 but not via PAR-4. Dose-response analysis over the enzyme concentration range 0.1-1000 nM indicated that KLK4-induced Ca(2+) mobilization via PAR-1 is more potent than via PAR-2, whereas KLK4 displayed greater efficacy via the latter PAR. We confirmed the specificity of KLK4 signaling via PAR-2 using in vitro protease cleavage assays and anti-phospho-ERK1/2/total ERK1/2 Western blot analysis of PAR-2-overexpressing and small interfering RNA-mediated receptor knockdown cell lines. Consistently, confocal microscopy analyses indicated that KLK4 initiates loss of PAR-2 from the cell surface and receptor internalization. Immunohistochemical analysis indicated the co-expression of agonist and PAR-2 in primary prostate cancer and bone metastases, suggesting that KLK4 signaling via this receptor will have pathological relevance. These data provide insight into KLK4-mediated cell signaling and suggest that signals induced by this enzyme via PARs may be important in prostate cancer.
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PMID:Kallikrein-related peptidase 4 (KLK4) initiates intracellular signaling via protease-activated receptors (PARs). KLK4 and PAR-2 are co-expressed during prostate cancer progression. 1830 30

While gastric cancer is a well established angiogenesis driven tumor, no data has been published regarding angiogenesis stimulated by mast cells (MCs) positive for tryptase in bone metastases from gastric cancer patients (BMGCP). It is well established that MCs play a role in immune responses and more recently it was demonstrated that MCs have been involved in tumor angiogenesis. We analyzed infiltrating MCs and neovascularization in BMGCP diagnosed by histology. A series of 15 stage T3-4N2-3M1 (by AJCC for Gastric Cancer Staging 7th Edition) BMGCP from bone biopsies were selected. Tumour tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of MCs density positive to tryptase (MCDPT), MCs area positive to tryptase (MCAPT), microvascular density (MVD) and endothelial area (EA). A significant correlation between MCDPT, MCAPT, MVD and EA groups to each other was found by Pearson and t-test analysis (r ranged from 0.68 to 0.82; p-value ranged from 0.00 to 0.02). Our very preliminary data suggest that infiltrating MCs positive for tryptase may play a role in BMGCP angiogenesis, and could be further evaluated as a novel target of anti-angiogenic therapy.
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PMID:Infiltrating mast cells correlate with angiogenesis in bone metastases from gastric cancer patients. 2564 23

Bone metastases from gastric cancer (GC) are considered a relatively uncommon finding; however, they are related to poorer prognosis. Both primary GC and its metastatic progression rely on angiogenesis. Several lines of evidence from GC patients strongly support the involvement of mast cells (MCs) positive to tryptase (MCPT) in primary gastric tumor angiogenesis. Recently, we analyzed infiltrating MCs and neovascularization in bone tissue metastases from primary GC patients, and observed a significant correlation between infiltrating MCPT and angiogenesis. Such a finding suggested the involvement of peritumoral MCPT by infiltrating surrounding tumor cells, and in bone metastasis angiogenesis from primary GC. Thus, an MCPT-stimulated angiogenic process could support the development of metastases in bone tissue. From this perspective, we aim to review the hypothetical involvement of tumor-infiltrating, peritumoral MCPT in angiogenesis-mediated GC cell growth in the bone microenvironment and in tumor-induced osteoclastic bone resorption. We also focus on the potential use of MCPT targeting agents, such as MCs tryptase inhibitors (gabexate mesylate, nafamostat mesylate) or c-KitR tyrosine kinase inhibitors (imatinib, masitinib), as possible new anti-angiogenic and anti-resorptive strategies for the treatment of GC patients affected by bone metastases.
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PMID:Targeting mast cells in gastric cancer with special reference to bone metastases. 2645 10