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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a study of the biologic consequences of using monoclonal antibodies (mAb) with specificity for I-A for the elimination of an I-A-bearing B cell lymphoma, it was found that, despite the presence of I-A on a number of normal cell types and the propensity of anti-I-A to induce modulation of I-A and I-E on normal cells in vivo, a substantial effect on lymphoma growth could be measured in mAb-treated hosts. Unlike I-A on normal cells, tumor I-A failed to modulate in vivo, and 50% of animals could be cured of lymphoma by multiple doses of anti-I-A mAb. With a sensitive spleen tumor colonization assay, it was shown that neither T lymphocytes nor natural killer cells were involved in tumor elimination by anti-I-A mAb. In addition, C3 depletion only minimally affected the ability of anti-I-A to inhibit tumor growth, suggesting that complement-dependent lysis of tumor cells was not a major mechanism. Spleen cells from long term survivors of tumor challenge and mAb treatment functioned normally as antigen-presenting cells and in the recognition of alloantigens, and serum Ig levels were somewhat higher than in untreated mice; thus, such therapy can be carried out without compromising the immune reactivity of long term survivors.
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PMID:Selective in vivo antitumor effects of monoclonal anti-I-A antibody on B cell lymphoma. 350 Sep 81

To establish a murine model for the monoclonal anti-idiotype immunotherapy of B cell lymphoma, a panel of rat and murine monoclonal anti-idiotype antibodies of several different isotypes was generated against the surface immunoglobulin of the murine B cell tumor 38C13 (38C). Xenogeneic antibodies were made from fusions of rat spleen cells immunized with the 38C idiotype. Syngeneic monoclonal anti-idiotypes were generated from mice immunized with the idiotype conjugated to the protein carrier KLH. Small differences were noted in the ability of the antibodies to cross-block one another, but all appeared to be directed against the same or closely spaced idiotopes on the immunoglobulin molecule. The antibodies selectively precipitated surface Ig from 38C tumor cells and not from normal mouse spleen cells. They were used to selectively stain 38C tumor cells in cell suspensions for FACS analysis or immunohistochemical staining of tissue sections from mice bearing the tumor. As the malignancy progressed, the number of tumor cells found in all tissues examined increased. Thus, the anti-Id antibodies provided a specific probe for tumor cell detection. The antibodies had no detectable effect on cell growth in vitro; however, they did cause the rapid transient loss of the expression of cell surface Ig. This modulation was concentration and time dependent but not 100% complete. Re-expression of the Id occurred by 24 h following removal of the anti-Id antibodies. When these antibodies were used in sensitive radioisotope and enzyme linked immunoassays, the tumor cells were found to secrete small amounts of idiotype in vitro and in vivo. The level of idiotype detected in vivo correlated with tumor growth and inversely with survival. This work is an attempt to develop further an animal model system in which to test the diagnostic and therapeutic effects of monoclonal anti-idiotype antibodies.
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PMID:Monoclonal anti-idiotype antibodies against the murine B cell lymphoma 38C13: characterization and use as probes for the biology of the tumor in vivo and in vitro. 389 6

Tumor dormancy can be induced in a murine B cell lymphoma (BCL1) by immunizing BALB/c mice with the tumor immunoglobulin (Ig) before tumor cell challenge. In this report, we have investigated the immunological and cellular mechanisms underlying the induction of dormancy. BCL1 tumor cells were injected into SCID mice passively immunized with antibody against different epitopes on IgM or IgD with or without idiotype (Id)-immune T lymphocytes. Results indicate that antibody to IgM is sufficient to induce a state of dormancy. Antibodies against other cell surface molecules including IgD and CD44 (Pgp1) had no effect on tumor growth. Id-immune T cells by themselves also had no effect on tumor growth in SCID mice. However, simultaneous transfer of anti-Id and Id-immune T cells enhanced both the induction and duration of the dormant state. In vitro studies indicated that antibody to IgM induced apoptosis within several hours and cell cycle arrest by 24 h. Hyper cross-linking increased apoptosis. The Fc gamma RII receptor played little or no role in the negative signaling. Antibodies that did not negatively signal in vitro did not induce dormancy in vivo. The results suggest that anti-IgM plays a decisive role in inducing tumor dormancy to BCL1 by acting as an agonist of IgM-mediated signal transduction pathways.
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PMID:Tumor dormancy and cell signaling. II. Antibody as an agonist in inducing dormancy of a B cell lymphoma in SCID mice. 753 41

Cultured tumor cell lines, tumor xenografts grown in athymic nude mice, and a murine experimental metastasis model were used to assess the in vitro and in vivo anti-tumor activity of the potent IMP dehydrogenase (IMPDH) inhibitor, mycophenolic acid (MPA), and its morpholinoethyl ester pro-drug, mycophenolate mofetil (MM). The growth of all the cell lines tested was inhibited by MPA in vitro, with EC50 values ranging from less than 0.1 microM to 3.9 microM. Mice were monitored for s.c. tumor outgrowth in the case of human tumor xenograft models or survival time for the murine experimental metastasis model. Treatment with MM p.o. was started 24 hr after tumor challenge or after tumors became palpable. Treatment of athymic nude mice bearing A3.01 (T-lymphoblast), Molt-4 (T-cell leukemia), CaPan-2 (pancreatic adenocarcinoma), CaLu-3 (non-small-cell lung adenocarcinoma), LS174T and T84 (colon adenocarcinoma), and Daudi (B-cell lymphoma) human tumor xenografts with MM significantly inhibited s.c. tumor growth. Treatment of BALB/c mice with MM after i.v. injection of murine RAW117-H10 lymphoma cells in an experimental metastasis assay resulted in increased survival time for treated animals. No significant inhibitory effect on s.c. tumor outgrowth was seen with MM treatment of SK-Hep-1, a human hepatic endothelioma, or Hep-3B, a liver adenocarcinoma, at any of the doses tested.
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PMID:Anti-tumor activity of mycophenolate mofetil against human and mouse tumors in vivo. 818 60

We reported previously on the successful use of bispecific antibodies in two well characterized B-cell lymphoma models. These bispecific antibodies were hybrid-hybridoma antibodies with dual specificity for the TcR/CD3 complex and for the tumor-specific idiotype of the surface IgM expressed by the lymphoma cells. Class-matched control antibodies, either monovalent for CD3, monovalent for idiotype, or bivalent for these surface markers, were always used in parallel with the bispecific antibodies. We extended our studies to determine the relative contribution of antibody-dependent cellular cytotoxicity and a T-cell-mediated therapeutic effect in the BCL1 lymphoma model. In tumor-bearing mice depleted of CD4+, CD8+ or both T-cell subsets and treated with bispecific antibodies, we could show that both T-cell populations contribute to the therapeutic outcome and have an additive role. In vitro studies demonstrate that bridging BCL1 tumor cells to T-cells by bispecific antibodies induces T-cell activation and secretion of tumor growth inhibiting lymphokines by both CD4+ and CD8+ T-cell populations. Particularly gamma-interferon seems to be the major tumor-inhibiting substance for BCL1 tumor cells. However, in vivo experiments using anti-cytokine antibodies showed that both gamma-interferon and tumor necrosis factor alpha have an effect on the tumor growth. The former acts directly by inhibiting tumor growth, the latter via an indirect mechanism, possibly by activating macrophages. In conclusion, our results show that induction of targeted cytolytic activity by the direct CD3/TcR cross-linking and development of targeted cytotoxic activity, mediated by gamma-interferon, by both T-cell subsets, contribute to the therapeutic success of bispecific antibody therapy.
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PMID:Role of T-cell subsets in the bispecific antibody (anti-idiotype x anti-CD3) treatment of the BCL1 lymphoma. 818 84

The spontaneously arising B-cell lymphoma (la+ reticulum cell sarcoma, RCS) in SJL/J mice has been shown to depend on host CD4 T cells for proliferation and growth. Treatment of mice with CD4 monoclonal antibody (mAb) prior to or after inoculation of a lethal dose of RCS tumor cells inhibits cell growth and the mice survive. The mechanism of tumor growth inhibition was studied by adoptively transferring cells from CD4 mAb treated tumor bearers into naive syngeneic mice. The recipient mice developed tumors and died. Tumor growth was dependent on the concentration of the adoptively transferred tumor cells. These results suggested that a state of tumor dormancy was established in the treated mice. Tumor dormancy was long lasting, as cells transferred as late as 11 weeks after the initial RCS inoculation still developed tumors in the recipient. The maintenance of dormancy was not due to failure of the recipient mice to mount an anti-tumor response or to the induction of suppressor cells. These results suggest that in the absence of CD4 cells, the RCS tumor remains dormant and this state of dormancy persists for long periods after total recovery of the CD4 cell subpopulation. Thus, it appears that RCS proliferation and growth is dependent on host CD4 cells but maintenance is under the influence of other cells or factors. Further characterization of this tumor dormant system and its regulation by the host may reveal novel mechanisms of tumor dormancy.
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PMID:Regulation of B-cell lymphoma growth in syngeneic SJL/J mice. establishment of tumor dormancy following administration of anti-CD4 monoclonal antibody into tumor-bearing mice. 823 Dec 49

This study explored the use of interleukin 2 (IL-2) and interferon gamma (IFN-gamma) gene-modified tumor cells as cellular vaccines for the treatment of bladder cancer. The mouse MBT-2 tumor used is an excellent model for human bladder cancer. This carcinogen-induced tumor of bladder origin resembles human bladder cancer in its etiology and histology, and responds to treatment in a manner similar to its human counterpart. Using retroviral vectors, the human IL-2 and mouse IFN-gamma genes were introduced and expressed in MBT-2 cells. The tumor-forming capacity of the cytokine gene-modified MBT-2 cells was significantly impaired, since no tumors formed in mice injected intradermally with either IL-2- or IFN-gamma-secreting cells, using cell doses far exceeding the minimal tumorigenic dose of parental MBT-2 cells. Furthermore, mice that rejected the IL-2- or IFN-gamma-secreting tumor cells became highly resistant to a subsequent challenge with parental MBT-2 cells, but not to 38C13 cells, a B cell lymphoma of the same genetic background. To approximate the conditions as closely as possible to the conditions prevailing in the cancer patient, inactivated cytokine-secreting cells were used to treat animals bearing tumors established by orthotopic implantation of MBT-2 cells into the bladder wall of the animal. Treatment of mice carrying a significant tumor burden with IL-2-secreting MBT-2 cells had a significant inhibitory effect on tumor progression with extended survival. Moreover, in 60% of the mice the tumor regressed completely and the animals remained alive and free of detectable tumor for the duration of the observation period. Treatment of tumor-bearing animals with IL-2-secreting MBT-2 cells was superior to the use of cisplatin, a chemotherapeutic agent used in the treatment of bladder cancer. The therapeutic effect of IFN-gamma-secreting cells was minimal and treatment with unmodified MBT-2 cells had no effect on tumor growth or survival, showing that the parental MBT-2 cells were nonimmunogenic in this experimental setting. Most importantly, mice that exhibited complete tumor regression after treatment with IL-2-secreting MBT-2 cells became resistant to a subsequent challenge with a highly tumorigenic dose of parental MBT-2 cells, indicating that long-term immunological memory was established in the "cured" mice.
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PMID:Regression of bladder tumors in mice treated with interleukin 2 gene-modified tumor cells. 845 7

We report a case of T-cell-rich large B-cell lymphoma demonstrating sick sinus syndrome as a single initial symptom, followed by the retention of pericardial and pleural effusions. Intrapleural administration of interferon-alpha prevented reaccumulation of the pleural effusion for one and a half months, whereas systemic chemotherapy failed to control tumor growth in the skin and lymph nodes. The autopsy revealed involvement of the sinoatrial node of the heart by lymphoma cells.
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PMID:Malignant lymphoma demonstrating sick sinus syndrome. 965 2

Antibody (Ab)-based tumor therapeutics use the tumor-binding specificity of the Ab to target Fc functions or associated molecules to the site of the tumor. We have used an Ab-interleukin-2 (IL-2) fusion protein to deliver IL-2 to a murine B cell lymphoma (38C13). This anti-Id IgG3-CH3-IL-2, which recognizes the idiotype present on the surface of the lymphoma has a half-life in mice approximately 17-fold longer than the half-life reported for IL-2. Gamma camera studies showed that anti-Id IgG3-CH3-IL-2 localizes at the site of a subcutaneous tumor in mice. The anti-Id IgG3-CH3-IL-2 also shows enhanced antitumor activity compared with the combination of Ab and IL-2 administered together. However, the mechanism of antitumor activity appears to depend on the dose and the treatment schedule used. A single dose of fusion protein prevented tumor in only 50% of the animals, although all the survivors showed some evidence of immunologic memory. Although multiple doses are more effective in preventing tumor growth (87% survivors), they are ineffective in generating protective immunologic memory. Our results suggest that Ab-IL-2 fusion proteins will be useful in the diagnosis and treatment of human B cell lymphomas and other related malignancies.
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PMID:An IgG3-IL-2 fusion protein recognizing a murine B cell lymphoma exhibits effective tumor imaging and antitumor activity. 972 41

Anti-idiotype (Id) antibodies (Abs) have been shown to be effective in treatment of B-cell lymphoma in animal models and in clinical trials. The combination of interleukin-2 (IL-2) can augment the therapeutic effect of anti-Id Abs. To further improve the power of the combined therapy, a monoclonal anti-Id Ab, S5A8, specifically recognizing a murine B-cell lymphoma 38C13, was genetically modified to contain the IL-2 domain and thus use the unique targeting ability of Abs to direct IL-2 to the tumor site. Two forms of the anti-Id-IL-2 fusion proteins were constructed: one configuration consisting of mouse-human chimeric IgG (chS5A8-IL-2) and the other containing only the variable light (VL) and variable heavy (VH) Ab domains covalently connected by a peptide linker (scFvS5A8-IL-2). Both forms of the anti-Id-IL-2 fusion proteins retained IL-2 biological activities and were equivalent in potentiating tumor cell lysis in vitro. In contrast, the antigen-binding ability of scFvS5A8-IL-2 was 30- to 40-fold lower than that of the bivalent chS5A8-IL-2. Pharmacokinetic analysis showed that scFvS5A8-IL-2 was eliminated about 20 times faster than chS5A8-IL-2. Finally, it was shown that chS5A8-IL-2 was very proficient in inhibiting 38C13 tumor growth in vivo, more effectively than a combined therapy with anti-Id Abs and IL-2, whereas scFvS5A8-IL-2 did not show any therapeutic effect. These results demonstrate that the anti-Id-IL-2 fusion protein represents a potent reagent for treatment for B-cell lymphoma and that the intact IgG fusion protein is far more effective than its single-chain counterpart.
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PMID:Treatment of B-cell lymphoma with chimeric IgG and single-chain Fv antibody-interleukin-2 fusion proteins. 973 Oct 68


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