Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0027627 (metastases)
103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies of metastasis can be accelerated and provide more mechanistic information using cell lines which reproducibly and aggressively metastasize, and which are accurately and easily detected in tissues at all stages of the metastatic process. Although reporter proteins such as green fluorescent protein (GFP) and beta-galactosidase have improved the tracking of tumor cells in vivo, their measurement has often been limited to visual observation and manual counting. In this study, we exploited the highly sensitive and objective quantitation provided by flow cytometry to characterize, in detail, the sequence of events associated with orthotopic metastasis in a highly aggressive mouse model. Following stable transfection of the MDA-MB-435 breast carcinoma cell line with GFP, we utilized an in vivo selection process to isolate a variant exhibiting increased primary tumor growth and metastasis. As few as one fluorescent tumor cell per 200,000 host cells could be accurately detected in dissociated tissues by flow cytometry, allowing us to demonstrate that metastatic cells migrate to the lungs of SCID mice very early after orthotopic implantation. Tumor burden in lungs increased in a smooth continuous manner, until death approximately eight weeks later. Levels of circulating tumor cells in blood were also detectable at an early timepoint, but remained relatively low throughout the course of secondary tumor development in the lungs. Surgical removal of the primary tumor at various times after inoculation significantly affected lung tumor burden, supporting the concept that circulating tumor cells in blood inefficiently initiate distal metastases. Furthermore, the continuing contribution to metastasis by the primary tumor was independent of tumor mass. The combined characteristics of enhanced orthotopic metastasis and quantitative detection in blood and tissues will make this a useful new model for the characterization of the multi-stage progression of cancer, and the preclinical evaluation of anti-neoplastic therapies.
Clin Exp Metastasis 1999
PMID:Characterization of spontaneous metastasis in an aggressive breast carcinoma model using flow cytometry. 1076 21

Colon carcinoma accounts for 20% of deaths due to malignancies in the Western world. Once metastases occur, therapeutic options are limited, with an approximate 5-year survival of only 5%. To investigate the potential of new gene therapeutic approaches, a hepatic micrometastasis model of colon carcinoma in BALB/c mice was established. Inoculation of syngeneic MCA26 colon carcinoma cells into the spleens of 18- to 20-week-old mice resulted in the formation of multiple hepatic metastases. Selective transduction of developing hepatic metastases was demonstrated using a beta-galactosidase-expressing recombinant adenovirus. Cytosine deaminase (CD) can metabolize 5-fluorocytosine into the chemotherapeutic reagent 5-fluorouracil (5FU). The antitumoral potential of this suicide gene therapy approach was explored by systemic application of a recombinant replication-deficient adenovirus encoding for the bacterial CD gene under the control of the cytomegalovirus promoter (Ad.CMV-CD). Injection into the tail vein of tumor-bearing mice resulted in delayed tumor growth with significant reduction in hepatic metastases. The potential of this experimental approach for possible future clinical applications was evaluated by investigating adenoviral transduction efficiency, 5FU sensitivity, and 5-fluorocytosine-dependent Ad.CMV-CD toxicity in a variety of human colon cancer cell lines. Although the murine cell lines MCA26 and CC36 were highly sensitive to 5FU, the human colon cancer cell lines showed a 1-100 times higher resistance to 5FU. Specific Ad.CMV-CD toxicity correlates with 5FU toxicity. Transduction efficiency in human colon carcinoma cell lines was shown to be 10-1700 times higher compared with murine cell lines, thus compensating for 5FU resistance. In conclusion, suicide gene therapy using CD may be promising as an adjuvant treatment regimen for hepatic micrometastases of human colon carcinoma.
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PMID:Gene therapy of metastatic colon carcinoma: regression of multiple hepatic metastases by adenoviral expression of bacterial cytosine deaminase. 1076 50

Several studies have indicated an interaction between tumor cells and infiltrating stromal cells regarding the urokinase plasminogen activation (uPA) system. By developing combined uPA gene-disrupted and immunodeficient mice, we have studied the role of stromal uPA for the growth of the MDA-MB-435 BAG human tumor xenograft. Subcutaneous tumor growth and lung metastasis were compared between wild-type immunodeficient mice and mice with the combined deficiencies. Tumor growth was evaluated by volume measurements and plasma beta-galactosidase activity and metastasis was evaluated by counting lung surface metastases. Although no differences appeared in primary tumor take between the two groups of mice, a significant difference was observed in primary tumor growth, with tumors in uPA-/- mice growing significantly more slowly. In addition, a nonsignificant trend toward fewer lung metastases in uPA-/- mice was observed. The present data points to a critical role of stromal-derived uPA in the primary tumor growth of MDA-MB-435 BAG xenografts, whereas only a trend toward fewer lung metastases in uPA gene-disrupted mice was found.
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PMID:Direct evidence of the importance of stromal urokinase plasminogen activator (uPA) in the growth of an experimental human breast cancer using a combined uPA gene-disrupted and immunodeficient xenograft model. 1121 46

Normal cells in culture divide a certain amount of times and undergo a process termed replicative senescence. Telomere loss is thought to control entry into senescence. Activation of telomerase in tumors bypasses cellular senescence and is thus a requirement for tumor progression. We reported previously the preferential incorporation of 3'-azido-2', 3'-dideoxythymidine (AZT) in telomeric sequences of immortalized cells in culture. In this work, we have investigated the effects of chronic in vitro AZT exposure on F3II mouse mammary carcinoma cells. We demonstrate, for the first time, that AZT-treated tumor cells have a reduced tumorigenicity in syngeneic BALB/c mice. Tumor incidence was reduced and survival was prolonged in animals inoculated with AZT-treated cells when comparing with control counterparts. The number and size of spontaneous metastases were also decreased in animals inoculated with AZT-treated cells. In addition, we present evidence of morphological and biochemical signs of senescence, as shown by the staining for senescence associated beta-galactosidase activity, and induction of programmed cell death, as demonstrated by an increase of caspase-3 activity, in tumor cells exposed to AZT. These data indicate that chronic exposure of mammary carcinoma cells to AZT may be sufficient to induce a senescent phenotype and to reduce tumorigenicity.
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PMID:Chronic in vitro exposure to 3'-azido-2', 3'-dideoxythymidine induces senescence and apoptosis and reduces tumorigenicity of metastatic mouse mammary tumor cells. 1126 35

Adenovirus (Ad) gene transfer vectors traffic to regional lymph nodes (RLNs) after footpad injections in mice, resulting in localized production of interferon gamma (IFN-gamma). With this background, we evaluated the hypothesis that Ad vector administration may inhibit RLN tumor metastasis independent of the transgene in the expression cassette. Tumors of MM48, a cell line with a propensity toward lymphogenous metastasis, were established in the footpads of syngeneic C3H mice, and E1(-)E3(-) Ad vectors encoding no transgene (AdNull) or encoding an irrelevant transgene (AdCD; Escherichia coli cytosine deaminase with no 5-fluorocytosine administration) were administered (10(10) particles) in a peritumoral location. Both vectors suppressed the growth of tumor in the regional (popliteal) lymph node. This effect was localized to the regional, but not distant, lymph nodes (p < 0.05). Heat inactivation of the vector or decreasing the dose of the vector to 10(9) particles did not suppress RLN growth of the tumor when compared with 10(10) particles of active AdNull (p < 0.05 and p < 0.01, respectively). The ability of an E1(-)E4(-) vector expressing beta-galactosidase (AdRSVbetagal.11) to suppress RLN tumor growth showed that the E4 region of the Ad vector was not responsible for the effect. Blocking either IFN-gamma or natural killer (NK) cells with systemic antibody treatment in immunocompetent mice allowed rapid growth of RLN metastases despite Ad vector administration, and Ad vector injection into the footpads of tumor-free mice induced the accumulation of NK cells in the RLN. These data demonstrate that, in a metastatic murine tumor model, a low dose (10(10) particles) of replication-deficient Ad vectors inhibits RLN metastases independent of a therapeutic transgene, an effect that is mediated, at least in part, by IFN-gamma and NK cells.
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PMID:Adenovirus gene transfer vectors inhibit growth of lymphatic tumor metastases independent of a therapeutic transgene. 1153 67

High-dose chemotherapy (HDCT) and autologous bone marrow transplantation (BMT) is frequently used to treat patients with metastatic cancer including breast cancer and neuroblastoma. However, the bone marrow of such patients is often contaminated with tumor cells. Recently, we have found that a recombinant adenovirus vector that contains a bcl-x, minigene (a dominant negative inhibitor of the bcl-2 family), called the bcl-x(s) adenovirus, is lethal to cancer cells derived from epithelial tissues, but not to normal human hematopoietic cells. To determine the mechanism, by which this virus spares normal hematopoietic cells, we isolated normal mouse hematopoietic stem cells and infected them with an adenovirus that contains a beta-galactosidase minigene. Such cells do not express beta-galactosidase, indicating that hematopoietic stem cells do not express transgene encoded by adenovirus vectors based upon the RSV-AD5 vector system. When breast cancer cells mixed with hematopoietic cells were infected with the bcl-x(s) adenovirus, cancer cells were selectively killed by the suicide adenoviruses. Hematopoietic cells exposed to the suicide vectors were able to reconstitute the bone marrow of mice exposed to lethal doses of y-irradiation. These studies suggest that adenovirus suicide vectors may provide a simple and effective method to selectively eliminate cancer cells derived from epithelial tissue that contaminate bone marrow to be used for autologous BMT. We therefore propose to initiate a phase I clinical trial to test the safety of this virus in women with breast cancer undergoing high does chemotherapy and autologous BMT.
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PMID:Clinical protocol. Purging of autologous stem cell sources with bcl-x(s) adenovirus for women undergoing high-dose chemotherapy for stage IV breast carcinoma. 1172 34

We evaluated the effect of gene therapy in the murine osteosarcoma cell line, LM8, which preferentially metastasizes to the lungs. LM8 cells were transduced with the gene for a herpes simplex virus thymidine kinase (HSV-tk) or Escherichia coli beta-galactosidase (lacZ). We investigated the cytotoxicity of LM8 cells bearing an HSV-tk gene after treatment with ganciclovir (GCV). LM8 cells bearing an HSV-tk gene were more sensitive than non-transduced cells. The remarkable inhibition of tumor growth and pulmonary metastases was confirmed in vivo. Our findings indicated that GCV kills tumor cells transduced with HSV-tk in vitro and in vivo.
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PMID:Suppression of tumor growth and pulmonary metastasis in murine osteosarcoma using gene therapy. 1183 3

Human solid tumors contain hypoxic regions that have considerably lower oxygen tension than normal tissues. These impart resistance to radiotherapy and anticancer chemotherapy, as well as predisposing to increased tumor metastases. To develop a potentially therapeutic protein drug highly specific for solid tumors, we constructed fusion proteins selectively stabilized in hypoxic tumor cells. A model fusion protein, oxygen-dependent degradation (ODD)-beta-galactosidase (beta-Gal), composed of a part of the ODD domain of hypoxia-inducible factor-1alpha fused to beta-Gal, showed increased stability in cultured cells under a hypoxia-mimic condition. When ODD-beta-Gal was further fused to the HIV-TAT protein transduction domain (TAT(47-57)) and i.p. injected to a tumor-bearing mouse, the biologically active fusion protein was specifically stabilized in solid tumors but was hardly detected in the normal tissue. Furthermore, when wild-type (WT) caspase-3 (Casp3(WT)) or its catalytically inactive mutant was fused to TAT-ODD and i.p. injected to a tumor-bearing mouse, the size of tumors was reduced by the administration of TAT-ODD-Casp3(WT) but not by TAT-ODD-mutant Casp3. TAT-ODD-Casp3(WT) did not cause any obvious side effects on tumor-bearing mice, suggesting specific stabilization and activation of the fusion protein in the hypoxic tumor cells. These results suggest that the combination of protein therapy using a cytotoxic TAT-ODD fusion protein with radiotherapy and chemotherapy may provide a new strategy for annihilating solid tumors.
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PMID:Antitumor effect of TAT-oxygen-dependent degradation-caspase-3 fusion protein specifically stabilized and activated in hypoxic tumor cells. 1192 18

Metastasis to the liver remains an important problem in the treatment of patients with gastrointestinal cancer. We examined the mechanism and effect on liver metastasis of in vivo interleukin-2 (IL-2) gene transfer to the liver. RCN-9 cells derived from F344 rat colon adenocarcinoma were injected into syngeneic rats via the ileocecal vein to induce liver tumors. A total of 2.5x10(9) pfu of adenovirus vector harboring the human IL-2 gene (AdCMVhIL-2), or 2.5x10(9) pfu of control vector encoding beta-galactosidase was administered before RCN-9 cell challenge. On day 14, mean tumor weight was 4.0+/-2.4 g in the control group, whereas IL-2-transduced livers had no tumors. Survival of AdCMVhIL-2-treated rats was significantly longer than that of control rats (P<.01). Flow cytometry demonstrated that the proportion of natural killer (NK) cells had increased among sinusoidal cells collected from IL-2-transduced livers. These cells were highly cytotoxic to RCN-9 cells in vitro in the presence of a physiological high concentration of recombinant IL-2. Preventative effects of IL-2 transduction of the liver against liver metastasis were lost after depletion of NK cells by treatment with anti-asialo GM1 antibodies. Our results indicate that IL-2 gene transfer to the liver prevents liver metastasis by continuously providing physiological high concentrations of IL-2 in the liver, thereby activating sinusoidal NK cells.
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PMID:Augmentation of local antitumor immunity in liver by interleukin-2 gene transfer via portal vein. 1271 13

This study has identified molecular changes characteristic of early oral cancer progression. We reported previously that acquisition of the immortal phenotype is an early event in oral cancer development (F. McGregor et al., Cancer Res., 57: 3886-3889, 1997); our current data indicate that about half of oral dysplasia cultures are immortal, and this is associated with loss of expression of retinoic acid receptor (RAR)-beta and the cell cycle inhibitor p16(ink4a) (p16), p53 mutations, and increased levels of telomerase/human telomerase reverse transcriptase mRNA. In contrast, increased expression of the epidermal growth factor receptor, known to be a characteristic of oral cancer, does not occur until after the dysplasia stage in squamous cell carcinomas. Acquisition of invasive properties as judged by an in vitro Matrigel invasion assay also does not occur until the carcinoma stage and is further increased in metastases. Interestingly, one atypical mortal dysplasia with a considerably extended life span has lost expression of RAR-beta and p16, but it still expresses only wild-type p53 (albeit at a higher level than normal) and has not activated telomerase. RAR-beta and/or p16 re-expression can be induced by treatment with 5-aza-2-deoxycytidine (Aza-C) in some immortal dysplasias, and this has been shown to be due to silencing of gene expression by promoter methylation. Aza-C treatment also down-regulated telomerase activity and human telomerase reverse transcriptase mRNA. Interestingly, with one dysplasia, Aza-C was able to reverse its immortal phenotype, as judged by morphological criteria and expression of the senescence-associated acid beta-galactosidase activity during terminal growth arrest; this immortal dysplasia was the only one in which Aza-C treatment not only down-regulated telomerase activity but also induced re-expression of both RAR-beta and p16. The possibility of reversing the immortal phenotype of some dysplasias by Aza-C may be of clinical usefulness.
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PMID:Molecular changes associated with oral dysplasia progression and acquisition of immortality: potential for its reversal by 5-azacytidine. 1218 35


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