Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Friend erythroleukemia cells (FLC) passaged in mice are highly tumorigenic and multiply extensively in the livers of suckling DBA/2 mice without differentiating. In contrast, in vitro passaged FLCs injected intravenously were of low tumorigenicity, multiplied to a limited extent in the livers of suckling mice, and underwent marked differentiation from the proerythroblast to the orthochromatic erythroblast stage in the liver. The presence of characteristic C-type virions budding from the cell surface in various stages of erythroid differentiation served as a marker of the injected FLCs. When the same in vitro passaged FLCs that differentiated in the liver were injected subcutaneously in suckling mice, they formed large subcutaneous tumors consisting of sheets of undifferentiated tumor cells. It is concluded that the tumorigenicity of FLCs depended on the site of tumor growth and that there is an inverse correlation between the tumorigenic capacity and the capacity to differentiate.
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PMID:Influence of the site of tumor growth on the capacity of a low tumorigenic line of Friend erythroleukemia cells to differentiate. 202 5

Lewis lung carcinoma (LLC) of C57BL/6 mice, a transplantable tumor widely metastatic by 6-7 days post implant (PI), caused hematopoietic alterations such as progressive anemia (hemoglobin: day 1 PI, 11.0 g/dl; day 19 PI, 7.8 g/dl), neutrophilia (neutrophils: day 1 PI, 2 X 10(3)/microliter; day 19 PI, 22 X 10(3)/microliter), and marrow and splenic myeloid hyperplasia (marrow myeloid-to-erythroid ratio: day 1 PI, 1:1; day 7 PI, 3:1). Accompanying these changes were an increased concentration of marrow granulocyte-macrophage colony-forming units (culture) (GM-CFUC) (day 3 PI, LLC 185 +/- 27% of control; day 19 PI, LLC 265 +/- 10% of control) and accelerated cycling of these myeloid progenitors [day 3 PI, LLC 45.3 +/- 6.5% GM-CFUC in cycle vs. sham (media) injected 17.5 +/- 10.5%; day 7 PI, LLC 52.2 +/- 2.5% vs. sham (media) injected 29.8 +/- 9.8%; day 11 PI, LLC 56.2 +/- 4.4% vs. sham (media) injected 22.2 +/- 14%]. This study questioned whether enhanced hematopoiesis was a result of progressive tumor growth or whether the injection of tumor cells could evoke the response. By use of groups of C57BL/6 mice given an injection of live LLC cells, x-irradiated killed LLC cells, or media, the hematopoietic response to live LLC cells versus dead LLC cells could be dissected. A biphasic colony-stimulating activity (CSA) response in the sera of tumor bearers was found to account for the myelopoietic changes. The first wave of CSA from days 1 to 3 PI stimulated 168 +/- 3.7% more GM-CFUC than control sera and was likely released by dead cells of the tumor inoculum; the second wave from day 7 onward stimulated 220 +/- 7.6% more colonies and was a result of the enlarging tumor mass. Tumor growth was necessary for GM-CFUC proliferation, and the declining growth fraction at day 19 in LLC-bearing mice suggested that hematopoietic exhaustion was a consequence of tumor growth.
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PMID:Early hematopoietic events during tumor growth in mice. 348 12

The ability of monoclonal antibodies (MAbs) against the murine transferrin receptor to inhibit the growth of transplanted syngeneic AKR/J SL-2 leukemic cells has been investigated. Two rat IgM antibodies, RI7 208 and REM 17.2, which both block transferrin receptor function, inhibited the growth of SL-2 leukemic cells in vitro at concentrations of 5-10 micrograms per ml. However, RI7 208 was more effective than REM 17.2 in prolonging survival of tumor-bearing mice. The antitumor effects of RI7 208 MAb were dependent on both the antibody dose and number of leukemic cells inoculated. The serum clearance of [75Se]methionine-labeled RI7 208 and REM 17.2 antibodies was similar and consisted of an initial rapid phase over the first 2 days followed by a slower phase. A single dose of 2 mg of antibody maintained a serum MAb concentration (greater than 10 micrograms/ml) sufficient to inhibit SL-2 leukemic cell growth in vitro for 2-3 days. The liver, kidney, and spleen were the major sites at which each of the antibodies accumulated regardless of whether trace or saturating amounts of antibody were administered. The specific activity of antibody found in s.c. SL-2 tumors was about 2-fold less than that of liver. It was shown that multiple doses of R17 208 MAb administered on a schedule aimed at maintaining a therapeutic serum level of MAb for 1-3 weeks were more effective than a single dose. Further, administration of RI7 208 MAb, in combination with the anti-Thy-1.1 MAb 19E12, was more effective than either antibody alone. SL-2 mutant cells were selected that were resistant to growth inhibitory effects of RI7 208 in vitro. The effects of RI7 208 MAb on the growth of these mutant cells in vivo suggests the major mechanism by which the MAb inhibits SL-2 tumor growth is by directly blocking receptor function. Acute toxicity associated with administration of the MAb was minimal. However, assays of myeloid and erythroid colony-forming units in bone marrow and spleen of mice given multiple doses of RI7 208 showed a depression of stem cell activity in bone marrow and elevated numbers of erythroid and cellular colony-forming units in the spleen.
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PMID:Effects of monoclonal antibodies that block transferrin receptor function on the in vivo growth of a syngeneic murine leukemia. 380 79

Growth of the Lewis lung (LLca) tumor in BDF1 mice was found to be accompanied by a marked expansion of the multipotential stem (CFUs-8) and committed erythroid (BFUe) and myeloid (CFU-gm) progenitor cells of the marrow with a concomitant depression of more differentiated compartments. The long-term effects of adriamycin (AdR), busulfan (BU), cis-diaminedichloroplatinum II (DDP), and 5-fluorouracil (5-FU) on the LLca-induced expansion of the CFUs-8 and CFU-gm were investigated at eight weeks after drug treatment. Of the four drugs studied, only BU demonstrated a reduction of CFUs-8 at eight weeks after treatment and prior to tumor inoculation. However, all of the drugs were found to prevent the expansion of the CFUs-8 compartment after 16 days of tumor growth. BU also resulted in a depressed CFU-gm compartment at the time of tumor inoculation, while CFU-gm in ADR-, DDP-, and 5-FU-treated animals was either at control levels (AdR), or unexpectedly elevated (DDP and 5-FU). Similar to the observations made for CFUs-8, all drugs prevented the expansion of the CFU-gm associated with tumor growth. The data suggest that qualitative differences observed between the long-term effects of the drugs on the marrow compartments may be more accurately related to the temporal "fixation" of residual drug damage brought about by enhanced differentiation of a drug-limited pluripotential CFUs, than to the actual magnitude of hematopoietic damage.
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PMID:Development of latent residual drug damage to the hematopoietic marrow during the subsequent growth of tumors. 394 28

Mice with skin tumors induced either by 7,12-dimethylbenz[a]anthracene complete carcinogenesis or subcutaneous injection of a carcinogenic keratinocyte cell line showed moderate to severe splenomegaly as a result of an increase in splenic granulocyte-macrophage and erythroid (erythroid burst-forming unit) progenitors. To test whether the observed alterations involve the release of soluble factors by the epidermal component of skin tumors, we used an in vitro approach. A series of mouse keratinocyte cell lines resembling progressive stages of skin carcinogenesis and carrying either normal or activated Ha-ras genes were assayed for their ability to produce the factors required for colony growth of hematopoietic-committed progenitors. Only the conditioned media of keratinocytes harboring activated Ha-ras genes were able to support the growth of granulocyte-macrophage colony-forming units. In addition, preincubation of normal bone-marrow cells with conditioned media from the transformed epidermal cell lines stimulated in vitro amplification of the hematopoietic granulocyte-macrophage progenitor compartment. To identify the possible factors responsible for the activities detected in the keratinocyte-conditioned media, we performed northern blot analysis using the cytokine probes granulocyte colony-stimulating factor, macrophage colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, stem cell factor, interleukin-1 alpha, interleukin-3, and tumor necrosis factor-alpha. The cell lines expressed different cytokine mRNA combinations that positively correlated with the colony-stimulating activity detected in the corresponding conditioned medium. These results suggest that transformed epidermal tumor cells in vivo may alter normal hematopoiesis as a consequence of the production of cytokines that act in autocrine or paracrine loops probably related to tumor growth.
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PMID:Augmented expression of cytokines in mouse epidermal tumor cells and its possible involvement in the induction of hematopoietic alterations. 794 4

The present study describes a new low molecular weight factor released by muscle cells, which inhibits proliferation of tumor cells in vitro and in vivo, is highly specific towards tumor cells, and has no observable effect on normal cells' proliferation. What first prompted us to investigate this factor was the observation that tumor metastases are extremely rare in striated muscles. Co-culturing of striated muscle cells with malignant cells led to marked morphological alterations in the latter, in contrast to the same cells when incubated without muscle cells. A conditioned medium of striated muscle cells was prepared and its effect tested on a variety of cells. This conditioned medium (CM) inhibited proliferation of tumor cell lines of murine (B16 melanoma, Madison 109 lung carcinoma, MCA-105 sarcoma, ESB lymphoma), or of human origin (HTB-38 adenocarcinoma, T47D breast carcinoma, CX1 colon carcinoma). The proliferation of normal cells (bone marrow cells, fetal liver erythroid cells) was not affected by the CM. Flow cytometric analysis of B16 melanoma cells following incubation with the CM revealed that 63% +/- 12 of the cells were in the G0/G1 phase of the cell cycle, compared to 47.8% +/- 8 of cells incubated with a medium (not conditioned) only. The activity of the CM and of certain fractions thereof was also demonstrated in vivo: they prevented tumor growth in mice inoculated intraperitoneally with MCA-105 sarcoma cells. Partial purification of the CM revealed that the active component was a non-proteinaceous compound with a molecular weight of about 500 D. The results clearly suggest that muscle cells produce a low molecular weight factor which can selectively inhibit the proliferation of tumor cells in vitro and in vivo. This factor is neither species nor tumor specific.
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PMID:Muscle cells produce a low molecular weight factor with anti-cancer activity. 867 72

The content of biologically active hemoglobin fragment neokyotorphin (TSKYR) as well as that of neokyotorphin fragment (1-4) (TSKY) were determined in extracts of lung, heart, and brain tissue of rats. The content of both peptides as well as the neokyotorphin/neokyotorphin(1-4) ratio differed significantly from each other in these tissues. The respective parameters deviate considerably from those of erythocytes where these peptides are originally formed. Comparative analysis of cytolytic activity of peptides was performed at human erythroid leukaemia (K562) and murine transformed fibroblast (L929) cell lines. TSKY showed reliable cytolytic activity in both cell lines, while neokytorphin was not cytotoxic. The data obtained lead to speculation that endogenous hemoglobin fragments might participate in regulation of tumor growth in vivo.
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PMID:Neokyotorphin and neokyotorphin (1-4): cytolytic activity and comparative levels in rat tissues. 871 13

Bone marrow (BM) stromal cells are required for normal hematopoiesis. A number of soluble factors secreted by these cells that mediate hematopoiesis have been characterized. However, the mechanism of hematopoiesis cannot be explained solely by these known factors, and the existence of other, still unknown stromal factors has been postulated. We showed that hepatocyte growth factor (HGF) is one such cytokine produced by human BM stromal cells. BM stromal cells were shown to constitutively produce HGF and also to express the c-MET/HGF receptor. The production of HGF was enhanced by addition of heparin and phorbol ester. Dexamethasone and tumor growth factor-beta (TGF-beta) inhibited the production of HGF. Interleukin-1 alpha (IL-1 alpha) tumor necrosis factor-alpha (TNF-alpha), and N6,2'-o-dibutyryl-adenosine-3':5'-cyclic monophosphate (dbc-AMP) showed no obvious influence on HGF production. Western blot analysis of HGF derived from BM stromal cells showed two bands at 85 and 28 kD corresponding to native and variant HGF, respectively. Addition of recombinant HGF significantly promoted the formation of burst-forming unit-erythroid (BFU-E) and colony-forming unit-granulocyte erythroid macrophage (CFU-GEM) by BM mononuclear cells in the presence of erythropoietin and granulocyte-macrophage colony-stimulating factor (GM-CSF), but the formation of CFU-GM was not modified. However, HGF had no effects on colony formation by purified CD34+ cells. Within BM mononuclear cells, c-MET was expressed on a proportion of cells (CD34-, CD33+, CD13+, CD14+, and CD15+), but was not found on CD34+ cells. We conclude that HGF is constitutively produced by BM stromal cells and that it enhances hematopoiesis. In addition, expression of c-MET on the stromal cells suggests the presence of an autocrine mechanism, operating through HGF, among stromal cells.
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PMID:Hepatocyte growth factor is constitutively produced by human bone marrow stromal cells and indirectly promotes hematopoiesis. 905 37

Type I interferons have potent antiproliferative activity both in vitro and in vivo, and their tumor suppressor activity has been suggested. A series of eukaryotic vectors containing a synthetic human consensus type I interferon gene (IFN-con1) under the control of different promoters (cytomegalovirus early promoter, murine metallothionein promoter and the Rous sarcoma virus LTR) were constructed and stably transfected into type I IFN-deficient myelogenous leukemic K562 cells. Constitutive expression of IFNcon1 reverted the malignant phenotype, as indicated by loss of tumorgenicity in nude mice. When stably transformed cells were mixed with parental tumor cells, there was retardation of tumor growth. Constitutive expression of IFNcon1 reverted the malignant phenotype in vitro, as indicated by growth inhibition in culture, and reduction in colony formation on soft agar. Furthermore, IFNcon1 gene expression resulted in elevated erythroid differentiation, growth arrest in S phase and induced apoptosis. Thus the presence of an active IFNcon1 gene overcomes the oncogenic potential of K562 by coordinated modulation of cell proliferation, differentiation and programmed cell death, and it acts as a tumor suppressor in vivo.
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PMID:Tumor suppressor activity of the human consensus type I interferon gene. 938 82

The tissue inhibitor of metalloproteinases-1 (TIMP-1) has at least 2 independent functions, i.e., regulation of matrix metalloproteinases and erythroid-potentiating activity. We investigated the effects of TIMP-1 over-expression on tumor growth, using cloned lines derived from a TIMP-1-transfected rat breast carcinoma cell line. The in vitro growth rate of the TIMP-1-transfected clones was indistinguishable from that of the control. In contrast, the highest TIMP-1-producing clone (159.0 ng/ml), designated as T-H, formed 4.6-fold larger s.c. tumors than did the control after 14 days. Tumors derived from an intermediate TIMP-1-producing clone (45.4 ng/ml), designated as T-M, were 1.9-fold larger than the control. TIMP-1 over-expression was associated with increased vascular endothelial growth factor (VEGF) expression, vascularization and proliferative activity of the s.c. tumors. Similar to the rat breast carcinoma cells, transfection of TIMP-1 cDNA into the human breast carcinoma cell line MCF-7 resulted in up-regulation of VEGF, with a linear relationship between TIMP-1 and VEGF production in 9 cell clones examined. There was, however, no change in VEGF expression when the rat and human breast carcinoma cell lines were exposed to exogenous recombinant TIMP-1. Our findings suggest that over-expression of TIMP-1 confers growth advantage on breast carcinoma cells in vivo and that up-regulation of VEGF expression may play an important role in this TIMP-1-mediated, growth-stimulating effect.
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PMID:Mammary carcinoma cells over-expressing tissue inhibitor of metalloproteinases-1 show enhanced vascular endothelial growth factor expression. 942 94


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