Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was undertaken to assess a multiple-marker RT-PCR and Southern blot assay for detection of metastases in frozen sections of sentinel lymph nodes from breast cancer patients. Sentinel lymphadenectomy was performed in 41 AJCC (American Joint Committee on Cancer) stage I-IIIA breast cancer patients and 57 sentinel nodes (SNs) were excised. The SN, which is the first node in the lymphatic basin to receive metastases from the primary tumor, was identified using isosulfan blue dye. Hematoxylin and eosin (H&E), immuno-histochemistry (IHC) and RT-PCR were performed on adjacent sections of the SN. Six consecutive 12-microm frozen sections of each SN were obtained for the RT-PCR assay to determine expression of mRNA tumor markers C-Met, beta1 --> 4GalNAc-T and P97. Metastatic breast cancer was detected by H&E in 10 of 57 (18%) SNs and by IHC in an additional 7 (12%). Only 1 of 17 (6%) SNs with metastases did not express any of the 3 tumor mRNA markers. C-Met, beta1 --> 4GalNAc-T and P97 tumor mRNA markers were expressed in 31 (78%), 21 (53%) and 25 (63%) of 40 SNs without metastases, respectively. At least 2 mRNA tumor markers were expressed in 25/40 (63%) histo-pathologically tumor-free SNs, whereas all 3 mRNA tumor markers were expressed in 17/40 (43%) SNs. Expression of all 3 mRNA tumor markers in a SN was significantly higher in patients with a family history of breast cancer (p = 0.05), prior history of breast cancer (p < 0.05), infiltrating lobular carcinoma (p = 0.06), estrogen receptor-negative (p = 0.04) tumor or a higher Bloom Richardson score (p = 0.04). The multiple-marker RT-PCR and Southern blot assay improves the detection of occult metastases in the SN when compared to conventional H&E and IHC analysis. Expression of all 3 tumor mRNA markers in the SN correlated with poor prognostic clinico-pathologic factors compared to expression of 0 to 2 markers.
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PMID:Detection of metastases in sentinel lymph nodes of breast cancer patients by multiple-marker RT-PCR. 984 76

The Met tyrosine kinase - the HGF receptor - induces cell transformation and metastasis when constitutively activated. Met signaling is mediated by phosphorylation of two carboxy-terminal tyrosines which act as docking sites for a number of SH2-containing molecules. These include Grb2 and p85 which couple the receptor, respectively, with Ras and PI 3-kinase. We previously showed that a Met mutant designed to obtain preferential coupling with Grb2 (Met2xGrb2) is permissive for motility, increases transformation, but - surprisingly - is impaired in causing invasion and metastasis. In this work we used Met mutants optimized for binding either p85 alone (Met2xPI3K) or p85 and Grb2 (MetPI3K/Grb2) to evaluate the relative importance of Ras and PI 3-kinase as downstream effectors of Met. Met2xPI3K was competent in eliciting motility, but not transformation, invasion, or metastasis. Conversely, MetP13K/Grb2 induced motility, transformation, invasion and metastasis as efficiently as wild type Met. Furthermore, the expression of constitutively active PI 3-kinase in cells transformed by the Met2xGrb2 mutant, fully rescued their ability to invade and metastasize. These data point to a central role for PI 3-kinase in Met-mediated invasiveness, and indicate that simultaneous activation of Ras and PI 3-kinase is required to unleash the Met metastatic potential.
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PMID:Concomitant activation of pathways downstream of Grb2 and PI 3-kinase is required for MET-mediated metastasis. 1002 19

The mechanism of metastasis of osteosarcoma cells to other bones has not yet fully been clarified. The purpose of the present study was to examine whether various factors involve the formation of osteosarcoma metastatic foci in other bones. Immunohistochemically, CD31 expression in osteosarcoma with no bone metastasis and osteosarcoma with bone metastasis was noted in 10 and 75% of cases, respectively. Met/hepatocyte growth factor (HGF) receptor expression in osteosarcoma with no bone metastasis and osteosarcoma with bone metastasis was noted in 90 and 25% of cases, respectively. Bone morphogenetic protein (BMP) expression in osteosarcoma with no bone metastasis and osteosarcoma with bone metastasis was noted in 20 and 75% of cases, respectively. Metastasis of osteosarcoma cells to other bones was significantly correlated with expression of BMP and CD31 and with no expression of Met/HGF receptor protein in osteosarcoma cells. In contrast, expression of insulin-like growth factor receptor in osteosarcoma cells did not correlate significantly with bone metastasis. These results suggest that formation of metastatic foci of osteosarcoma cells in other bones is regulated by CD31, which is associated with migration between endothelial cells, by BMP, which can induce and activate various mesenchymal cells affecting bone formation, and by escape of effect by HGF, which promotes differentiation of osteosarcoma cells.
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PMID:Expression of CD31, Met/hepatocyte growth factor receptor and bone morphogenetic protein in bone metastasis of osteosarcoma. 1116 48

Human cutaneous fatty acid-binding protein (C-FABP) gene is capable of inducing the metastatic phenotype when overexpressed in nonmetastatic rat Rama 37 cells. However, the mechanism of how it induces metastasis is not clear. Northern and slot blot analyses revealed that expression of the endogenous vascular endothelial growth factor (VEGF) gene was increased by 3.8-5.2-fold in the C-FABP-transfected cells (pSV-CFABP-R37) and in their metastatic sublines (e.g., Met-1) when compared with that in the nonmetastatic control transfectant pSV-R37 cells generated by transfection of only plasmid DNA. Higher levels of VEGF immunoreactive protein were also secreted from the malignant C-FABP-expressing cells. Reverse transcription-PCR detected two VEGF transcript isoforms, VEGF(164) and VEGF(188), in both the nonmetastatic control transfectant pSV-R37 cells and the malignant metastatic Met-1 cells. Chick chorioallantoic membrane assays showed that the conditioned medium of the control pSV-R37 cells possessed only very weak angiogenic activity, whereas conditioned media from the metastatic C-FABP transfectants and their sublines were strongly angiogenic and could be inhibited by antibodies to VEGF. Transfection of VEGF(164) cDNA in an expression vector into nonmetastatic Rama 37 cells produced a cell clone (R37-VEGF-2) that expressed high levels of VEGF. Inoculation of R37-VEGF-2 cells into syngeneic Wistar Furth rats produced metastases in a significant number (Fisher's exact test, P < 0.01) of animals (18 of 31 animals), whereas the control, vector alone-transfected R37-PSV cells produced no metastases (0 of 30 animals). Immunocytochemical methods demonstrated a strong positive staining for VEGF and an increased microvessel density in the primary tumors produced from PSV-VEGF-2 cells in comparison with tumors produced from control transfectants. Immunocytochemical staining for factor VIII detected a 3.5-fold increase in microvessel density of the primary tumors produced by PSV-VEGF-2 cells when compared with that of the primary tumors developed from the control pSV-R37 cells. Therefore, we suggest that overexpression of the C-FABP gene in the original transfectants induces metastasis through up-regulation of expression of the VEGF gene in this rat Rama 37 model system, and thus VEGF may play a crucial role in this particular metastatic cascade.
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PMID:Human cutaneous fatty acid-binding protein induces metastasis by up-regulating the expression of vascular endothelial growth factor gene in rat Rama 37 model cells. 1138 60

Small 1,000-bp fragments of genomic DNA obtained from human malignant breast cancer cell lines when transfected into a benign rat mammary cell line enhance transcription of the osteopontin gene and thereby cause the cells to metastasize in syngeneic rats. To identify the molecular events underlying this process, transient cotransfections of an osteopontin promoter-reporter construct and fragments of one metastasis-inducing DNA (Met-DNA) have identified the active components in the Met-DNA as the binding sites for the T-cell factor (Tcf) family of transcription factors. Incubation of cell extracts with active DNA fragments containing the sequence CAAAG caused retardation of their mobilities on polyacrylamide gels, and Western blotting identified Tcf-4, beta-catenin, and E-cadherin in the relevant DNA complexes in vitro. Transfection of an expression vector for Tcf-4 inhibited the stimulated activity of the osteopontin promoter-reporter construct caused by transiently transfected active fragments of Met-DNA or permanently transfected Met-DNA. This stimulated activity of the osteopontin promoter-reporter construct is accompanied by an increase in endogenous osteopontin mRNA but not in fos or actin mRNAs in the transfected cells. Permanent transfection of the benign rat mammary cell line with a 20-bp fragment from the Met-DNA containing the Tcf recognition sequence CAAAG caused an enhanced permanent production of endogenous osteopontin protein in vitro and induced the cells to metastasize in syngeneic rats in vivo. The corresponding fragment without the CAAAG sequence was without either effect. Therefore, the regulatory effect of the C9-Met-DNA is exerted, at least in part, by a CAAAG sequence that can sequester the endogenous inhibitory Tcf-4 and thereby promote transcription of osteopontin, the direct effector of metastasis in this system.
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PMID:Metastasis-inducing dna regulates the expression of the osteopontin gene by binding the transcription factor Tcf-4. 1145 16

North American women have a one in eight lifetime risk of developing breast cancer, and approximately one in three women with breast cancer will die of metastases. We, and others, have recently shown that high levels of expression of hepatocyte growth factor (HGF) and its receptor Met are associated with invasive human breast cancer and may be causally linked to metastasis. This high level of HGF and Met expression has been considered as a possible indicator of earlier recurrence and shortened survival in breast cancer patients. In contrast, HGF expression (but not Met) is strongly suppressed in normal breast epithelial cells. HGF and Met are therefore candidate targets for therapeutic intervention in the treatment of breast cancer. We have recently demonstrated that sustained activation or hyper-activation of c-Src and Stat3, which occurs in invasive breast cancer, can stimulate strong expression of HGF in carcinoma cells. In contrast, transient induction of Stat3 occurs in normal epithelium and promotes mammary tubulogenesis. We hypothesize that increased autocrine HGF-Met signaling is a critical downstream function of c-Src-Stat3 activation in mammary tumorigenesis. Future studies will identify novel Stat3 consensus sites that regulate HGF promoter activity and HGF expression preferentially in carcinoma cells and could lead to novel therapeutic drugs that specifically block HGF expression in mammary carcinoma cells, and which could be used in combined treatments to abrogate metastasis.
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PMID:The role of hepatocyte growth factor (scatter factor) in epithelial-mesenchymal transition and breast cancer. 1193 61

The high sensitivity of the pentagastrin stimulation test in detecting primary or metastatic medullary thyroid cancer (MTC) suggests a widespread expression of the corresponding receptor type on human MTC. Indeed, autoradiographic studies demonstrated cholecystokinin (CCK)-B/gastrin receptors not only in more than 90% of MTCs, but also in a high percentage of small-cell lung cancers, stromal ovarian tumors, and potentially a variety of other tumors, including gastrointestinal adenocarcinomas, neuroendocrine tumors, and malignant glioma. The aim of our work was to develop and systematically optimize suitable radioligands for targeting CCK-B receptors in vivo and to investigate their role in the staging and therapy of MTC and other CCK-B receptor expressing malignancies. For this purpose, a variety of CCK/gastrin-related peptides, all having in common the C-terminal CCK-receptor binding tetrapeptide sequence-Trp-Met-Asp-PheNH(2) or derivatives thereof, were investigated. They were members of the gastrin or cholecystokinin families or possessed characteristics of both, which differ by the intramolecular position of a tyrosyl moiety. Their stability and affinity were studied and optimized in vitro and in vivo; their biodistribution and therapeutic efficacy were tested in preclinical models. Best tumor uptake and tumor to nontumor ratios were obtained with members of the gastrin family, because of their superior selectivity and affinity for the CCK-B receptor subtype. Radiometal-labeled derivates of minigastrin showed excellent targeting of CCK-B receptor expressing tissues in animals and healthy human volunteers. Preclinical therapy experiments in MTC-bearing animals showed significant antitumor efficacy. In a subsequent clinical study, 45 MTC patients with metastatic MTC were investigated; 23 had known and 22 had occult disease. CCK-B receptor scintigraphy was performed with (111)In-diethylenetriamine pentaacetic acid-d-Glu(1)-minigastrin. The normal organ uptake was essentially confined to the stomach (and, to a lesser extent, to the gallbladder and, in premenopausal women, to normal breast tissue) as a result of CCK-B receptor specific binding and to the kidneys, as excretory organs. All tumor manifestations known from conventional imaging were visualized as early as 1 hour postinjection, with increasing tumor to background ratios over time; at least 1 lesion was detected in 20 of 22 patients with occult disease (patient-based sensitivity, 91%). Among them were local recurrences and lymph node, pulmonary, hepatic, splenic, and bone (marrow) metastases. Eight patients with advanced metastatic disease were injected in a dose-escalation study with potentially therapeutic activities of a (90)Y-labeled minigastrin derivative at 4 to 6-week intervals (30-50 mCi/m(2) per injection for a maximum of 4 injections). Hematologic and renal toxicities were identified as the dose-limiting toxicities at the 40 and 50 mCi/m(2) levels. Two patients experienced partial remissions, and 4 experienced stabilization of their previously rapidly progressing disease. These data suggest that CCK-B receptor ligands may be a useful new class of receptor-binding peptides for diagnosis and therapy of a variety of (CCK-B receptor expressing) tumor types. They allow for sensitive and reliable staging of patients with metastatic MTC. Initial therapeutic results are promising, but nephrotoxicity is a major concern to be solved.
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PMID:Cholecystokinin-B/Gastrin receptor-targeting peptides for staging and therapy of medullary thyroid cancer and other cholecystokinin-B receptor-expressing malignancies. 1196 5

The availability of a test to assess the likelihood that a given tumor will invade or metastasize would be a useful development in clinical oncology. We propose that multimodality imaging of tumor expression of Met could serve as a prototype for metastatic risk stratification (MRS). Met, a receptor protein tyrosine kinase, is expressed by most solid tumors, and aberrant expression of Met is associated with poor clinical prognosis. We summarize the current status and predict the future direction of research in four areas of molecular imaging and cancer therapy that exploit Met.
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PMID:Grappling with metastatic risk: bringing molecular imaging of Met expression toward clinical use. 1255 18

Nuclear medicine is engaged with the detection of pathological processes with the help of radionuclides. An interesting approach is to target antigens, symporters, or receptors with diagnostic and therapeutic radionuclides. Different peptide receptors like somatostatin, bombesin/GRP or VIP are (over)expressed on cancer cells, and are therefore an ideal target for the diagnosis and therapy in nuclear medicine with radiolabeled peptides. The somatostatin analogue OctreoScan [octreotide coupled with diethylene-triamine-pentaacetate (DTPA)] can be labeled with In-111 and is widely used in nuclear oncology for the staging of different tumors (e.g., carcinoids). Other peptides like neurotensin, bombesin/GRP, and VIP are under (pre)clinical investigations. The staging of metastatic medullary thyroid cancer (MTC) with the conventional radiological procedures is sometimes difficult. The high sensitivity of the pentagastrin stimulation test in detecting primary or metastatic MTC indicates the presence of tumor, but its localization is often not possible. This reaction of the tumor cells to the pentagastrin stimulation test suggests a widespread expression of the corresponding receptor type on human MTC. Indeed, autoradiographic studies demonstrated cholecystokinin (CCK)-B/gastrin receptors not only in over 90% of MTCs, but in a high percentage of small cell lung cancers, stromal ovarian, and potentially a variety of other tumors, including gastrointestinal adenocarcinomas, neuroendocrine tumors, and malignant glioma. The aim of our recent work was to develop and systematically optimize suitable radioligands for targeting CCK-B receptors in vivo and to investigate their role in the staging and therapy of MTC and other CCK-B receptor expressing malignancies. For this purpose, a variety of CCK/gastrin-related peptides, all having in common the C-terminal CCK receptor binding tetrapeptide sequence -Trp-Met-Asp-PheNH(2) or derivatives thereof, were investigated. They were members of the gastrin- or cholecystokinin families, or possessed characteristics of both, which differ by the intramolecular position of a tyrosyl moiety. Their stability and affinity were studied and optimized in vitro and in vivo; their biodistribution and therapeutic efficacy were tested in preclinical models. Best tumor uptake and tumor-to-nontumor ratios were obtained with members of the gastrin family, due to their superior selectivity and affinity for the CCK-B receptor subtype. Radiometal-labeled derivatives of minigastrin showed excellent targeting of CCK-B receptor expressing tissues in animals and healthy human volunteers. Preclinical therapy experiments in MTC-bearing animals showed significant antitumor efficacy. In a subsequent clinical study, 75 MTC patients with metastatic MTC were investigated; 43 suffered of known, 32 of occult disease. CCK-B receptor scintigraphy was performed with (111)In-DTPA-D-Glu(1)-minigastrin. The normal organ uptake was essentially confined to the stomach (and to a lower extent, to the gallbladder and, in premenopausal women, to normal breast tissue) as a result of CCK-B receptor specific binding, and to the kidneys as excretory organs. All tumor manifestations known from conventional imaging were visualized as early as 1 h p.i., with increasing tumor-to-background ratios over time; at least one lesion was detected in 29/32 patients with occult disease (patient-based sensitivity 91%). Among them were local recurrences, lymph node, pulmonary, hepatic, splenic, and bone (marrow) metastases. Eight patients with advanced metastatic disease were injected in a dose-escalation study with potentially therapeutic activities of a (90)Y-labeled minigastrin derivative at 4-6-weekly intervals (30-50 mCi/m(2) per injection for a maximum of four injections). Hematologic and renal were identified as the dose-limiting toxicities at the 40 and 50 mCi/m(2) levels. Two patients experienced partial remissions, 4 stabilization of their previously rapidly progressing disease. These data suggest that CCK-B receptor ligands may be a useful new class of receptor binding peptides for diagnosis and therapy of a variety of (CCK-B receptor expressing) tumor types. They allow for a sensitive and reliable staging of patients with metastatic MTC. Initial therapeutic results are promising, but nephrotoxicity is a major concern to be solved.
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PMID:Cholecystokinin-B (CCK-B)/gastrin receptor targeting peptides for staging and therapy of medullary thyroid cancer and other CCK-B receptor expressing malignancies. 1265 27

Met, the receptor for hepatocyte growth factor (HGF), is activated in human cancer by both ligand-dependent and -independent mechanisms. We engineered a soluble Met receptor (decoy Met) that interferes with both HGF binding to Met and Met homodimerization. By lentiviral vector technology, we achieved local or systemic delivery of decoy Met in mice. We provide evidence that in vivo expression of decoy Met (1) inhibits tumor cell proliferation and survival in a variety of human xenografts, (2) impairs tumor angiogenesis by preventing host vessel arborization, (3) suppresses or prevents the formation of spontaneous metastases, and (4) synergizes with radiotherapy in inducing tumor regression, without (5) affecting housekeeping physiological functions in the adult animal.
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PMID:Targeting the tumor and its microenvironment by a dual-function decoy Met receptor. 1526 Nov 36


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