Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A great deal of information has emerged over the past decade regarding the gene structures and corresponding protein products of the cellular and transformation-associated forms of the ABL tyrosine kinase family. Many reports have also detailed the biological effects of these proteins (particularly the viral ABL forms) on a broad range of cell types. However, in spite of all these research efforts, the precise role of the ABL gene in normal and neoplastic growth remains to be determined. To elucidate the mechanism of action of normal and altered ABL proteins, it is imperative to identify their relevant cellular substrates and establish the role of the ABL target proteins in transformation and normal cellular growth. The availability of temperature-sensitive ABL proteins, coupled with the use of sensitive anti-phosphotyrosine antibodies, should be useful in this respect. Purification of enzymatically active, intact forms of the ABL proteins produced in insect cells by employing baculovirus expression vectors should permit direct comparison of the biochemical properties and tertiary structures of the various members of the ABL protein kinase family. Such studies will aid in understanding the nature of the alteration of ABL which results in the activation of its transforming potential. Furthermore, the availability of purified ABL proteins should permit examination of interactions of ABL with other growth-regulatory proteins, such as growth factor receptors. It has been shown that transformation-associated ABL proteins interact with the IL-3, IL-2 and GM-CSF growth-factor pathways. These and other components of the cellular signalling pathways are potential ABL targets. The elucidation of ABL function by a variety of approaches such as those described above will ultimately aid in the development of far-reaching therapeutic treatments for at least two forms of human leukaemia: Ph positive CML and Ph positive ALL.
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PMID:Role of the ABL oncogene tyrosine kinase activity in human leukaemia. 333 51

We carried out a total of 36 in vivo chemosensitivity tests in 33 cases of human malignant tumor using the subrenal capsule assay, developed by A.E. Bogden et al. Of the 36 assays, 31 were evaluable. The chemosensitivity of each tumor varied individually. UFT, 5-fluorouracil, mitomycin-C and adriamycin were administered to gastrointestinal cancer patients regularly, but our SRC-assay showed a high sensitivity rate for UFT and 5-fluorouracil but a low sensitivity rate for mitomycin-C and adriamycin. Nine patients had clinically evaluable lesions and a correlation between the assay results and clinical response existed in 6 cases. The true positive rate was 50% (3/6), the true negative rate 100% (3/3), and the overall predictive accuracy 66% (6/9). This study suggested that 6-day SRC assay is useful for selecting effective anti-tumor agents for the treatment of cancer patients.
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PMID:[A six-day subrenal capsule assay for predictive testing of primary human tumors]. 333 30

Chemosensitivity of liver cell carcinoma was studied by subrenal capsule assay. The method of assay was based on Bogden's one, but the antitumor activity was evaluated by tumor growth inhibition rate (TG-IR). The anticancer agent with more than 50% TG-IR was judged as positive in the chemosensitivity test. Of 3 human hepatoma cell lines transplanted in the subcutaneous space of nude mice, all of 3 were evaluable. The positive rates of ADR, MMC, CDDP, 5-FU and CPA were 66.7%, 100%, 66.7%, 100% and 0%, respectively. Of 24 patients who provided fresh tumor specimens for the assay, 12 (50%) were evaluable. The positive rates of ADR, MMC, CDDP, 5-FU and CPA were 25%, 16.7%, 16.7%, 33.3% and 8.3%, respectively. Our study suggested that 5-FU, MMC and ADR were comparatively active against the hepatoma cell, CDDP was less active than these 3 agents, CPA was inactive. These results seem to justify the use of current anticancer agents against hepatic cell carcinoma and indicate the usefulness of SRC assay for selecting chemotherapeutic agents against liver cell carcinoma.
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PMID:[Study on the chemosensitivity of liver cell carcinoma by subrenal capsule assay]. 334 29

Six-day SRC assay as a chemosensitivity test has an advantage of high predictive rate for clinical response. However, it is pointed out that very few viable tumor cells are observed at the end of the assay, so that it may make the assay results unreliable. In this paper, we tested the effect of immunosuppressants on SRC assay using Walker carcinosarcoma originated from Wistar rat xenografted under the renal capsule of BDF1 mice. The changes of tumor size, pathological features and proliferative ability of xenografted tumor under the renal capsule of mice treated with cyclophosphamide, mizolibine or cyclosporin A are examined. Only cyclosporin A treatment could maintain the viable tumor cells and proliferative ability of the tumor grafted under the renal capsule 21 days after transplantation. In order to compare the original 6-day SRC assay developed by Bogden et al, we applied immunosuppressants to the 6-day assay. It is suggested that cyclosporin A and mizolibine amplify the sensitivity of tumor in 6-day SRC assay.
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PMID:[Effect of immunosuppressants on the subrenal capsule (SRC) assay as a chemosensitivity test]. 334 31

This study was designed to evaluate the interaction of photodynamic therapy (PDT) and chemotherapy in an animal model. PDT is based on the interaction of hematoporphyrin derivative and red light of the appropriate wavelength (630 nm) and intensity. Two tumor models were utilized: C3H/Km mice bearing the RIF-1 tumor and BALB/c mice bearing the EMT-6 tumor. Tumor-bearing mice were treated with either cisplatin (DDP), doxorubicin (ADM), PDT, or a combination of drug and PDT. It was demonstrated that the RIF-1 tumor was sensitive to DDP and insensitive to both PDT and ADM. There was no additional antitumor effect when either drug was combined with PDT. The EMT-6 tumor was moderately sensitive to PDT and mildly sensitive to both DDP and ADM. Although the addition of DDP did not potentiate tumor destruction, the addition of ADM significantly enhanced the effect of PDT (P = .01). The enhanced activity of the combination of PDT and ADM appeared to be the result of increased activity of ADM alone, when illuminated with red (630 nm) light. This potentiation may be due to a photochemical process or may be secondary to the mild hyperthermia generated by illumination with the laser. This study demonstrates that PDT combined with cytotoxic chemotherapy is well tolerated in these animals and that certain combinations of PDT and chemotherapy may result in an enhanced tumoricidal effect.
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PMID:Combination cytotoxic chemotherapy with cisplatin or doxorubicin and photodynamic therapy in murine tumors. 338 81

In vivo and in vitro chemosensitivity testing has been applied to kidney carcinoma tumor lines. Serially transplantable tumors were implanted subcutaneously in nude mice and the animals were treated with cytostatic drugs. The results of this in vivo assay were compared with the results obtained with the subrenal capsule assay, the DNA precursor assay (3H-thymidine), and the colony-formation assay, utilizing the same tumor line in each case. Higher rates of resistant tumors were found in the in vivo assays than in the in vitro assays. The SRC assay and the DNA assay had the highest predictive value, as judged from comparison with the results obtained with the source tumor (human kidney carcinoma tumor line).
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PMID:In vivo and in vitro chemotherapy sensitivity testing for human kidney tumor lines: a comparative study. 339 74

We assessed the use of a colorimetric assay for determination of radiosensitivity for cells taken directly from murine solid tumors. The assay uses microtier plates and measures the ability of viable cells to reduce a tetrazolium salt (MTT) to an insoluble form, a formazan salt. We established the dependency of the assay on the cell number and time of assay for two murine tumors (EMT-6 and RIF-1). We compared the MTT assay to the standard clonogenic assay and had good agreement of surviving fraction after radiation doses of 2 and 4 Gy. It is possible, therefore, to adapt the MTT assay for use with cell suspensions prepared directly from fresh murine tumors. This may provide a methodology for the determination of the clinical radiosensitivity of tumors including fresh clinical tumor specimens.
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PMID:Use of a colorimetric microtiter (MTT) assay in determining the radiosensitivity of cells from murine solid tumors. 341 90

Culture medium conditioned by incubation with murine cytotoxic activated macrophages causes release of iron-55 label from viable murine EMT-6 tumor cells as well as inhibition of DNA replication and aconitase activity. These metabolic changes occur in parallel with L-citrulline, nitrate, and nitrate synthesis from L-arginine by EMT-6 cells. Protein synthesis is required for activation of this effector mechanism. Once the effector pathway is induced in EMT-6 cells in the presence of amino acids, L-arginine is the only amino acid required for its function. Arginase inhibits the effector mechanism, which is additional evidence for its specific L-arginine requirement. The results show induction, in a non-macrophage cell line, of a novel effector pathway which, in addition to other effects, inhibits cellular proliferation.
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PMID:The L-arginine dependent effector mechanism is induced in murine adenocarcinoma cells by culture supernatant from cytotoxic activated macrophages. 342 89

67Ga citrate and 99mTc citrate (Solcocitran) were injected sequentially, with an interval of 48 h, into Balb/c mice bearing transplanted EMT-6 tumors. Tissue distributions of 67Ga and 99mTc were measured simultaneously at intervals of 1, 3, 5 and 8 h after injection of the 99mTc citrate (49, 51, 53 and 56 h after 67Ga citrate). Maximal tumor:blood ratios for 67Ga and 99mTc were 13.8 +/- 3.2 and 4.0 +/- 1.0 respectively, both occurring at the final period. The maximum tumor index (T.I. = T:B X % dose/g) for 67Ga was 71 +/- 23% 56 h after injection, and for 99mTc was 13 +/- 12% 1 h after injection. Liver, kidney and spleen had equal or higher concentrations of radioactivity than tumor for either radiotracer. The somewhat higher tumor:blood ratio for 67Ga citrate was offset by the time required for this optimum to be reached. Alternatively, the best 99mTc citrate tumor:blood ratios were attained within 8 h, with less liver and gut radioactivity. These data fall within the range of results from other clinical and animal model studies of 67Ga citrate and 99mTc citrate. In view of the radiation dose, the inconvenience of the 48-72 h wait, and the cost of 67Ga, and because neither radiopharmaceutical is tumor specific, 99mTc citrate may have a place in early oncological screening. The results are discussed as part of a comprehensive review of the 99mTc citrate literature.
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PMID:Comparative studies of radiocitrates in oncological models--I. 99mTc citrate and 67Ga citrate uptake by EMT-6 tumors in mice. 346 79

The mechanism(s) with which tumor target cells actively resist the lethal lesion induced by murine macrophage cytolytic factory (CF) has been probed by drug-induced sensitization of these cells. We have examined whether drug-induced sensitization is attributable to the action of these drugs on cellular DNA, RNA, or protein synthetic rates. The murine mammary adenocarcinoma cell line EMT-6 pretreated with a dose range of actinomycin-D (.03-3.0 micrograms/ml) for 4 hr was inhibited from 66 to 98% in DNA synthesis rate, from 81 to 93% in RNA synthesis rate, and from 38 to 52% in protein synthesis rate. The maximum sensitization toward lysis by CF was achieved with a drug dose of 1.0 micrograms/ml. The lack of correlation between the drug-induced effects on sensitization and effects on these metabolic rates was evident from the correlation coefficients for the percentage of maximum sensitization of the target toward CF-induced lysis, and the percent of inhibition of DNA, RNA, and protein synthesis. These were 0.11, -0.11, -0.44, respectively. Similarly, target cells treated with a dose range of cycloheximide (0.3-30 micrograms/ml) were inhibited from 81 to 95% in DNA synthesis rate, 68 to 81% in RNA synthesis rate, and 82 to 93% in protein synthesis rate. However, at none of the drug levels employed was significant sensitization of the target cell to CF-induced lysis observed. This was reflected in the correlation coefficients of -0.55, -0.28, and -0.34 for DNA, RNA, and protein synthetic rates, respectively. The essential role of cellular microtubule-dependent events early in the lytic mechanism was demonstrated by exposing colchicone-treated targets to CF. While colchicone could markedly inhibit lysis if introduced before CF, this inhibitory effect was not detected if the drug were withheld for 4 hr after CF exposure. The importance of the repair mechanism(s) early in the cellular response to lesion formation was demonstrated by altering the schedule for CF and actinomycin D administration to the target. If actinomycin D treatment was withheld from the targets for as little as 3 hr following introduction of CF, the lytic mechanism had already bypassed the drug-sensitive steps, manifest in markedly decreased susceptibility to lysis. Collectively, the data show that the ability of the EMT-6 target cells to resist CF-induced lysis does not depend solely on the ability of the cells to synthesize DNA, RNA, or protein.
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PMID:Sensitization of tumor target cells to cytolysis by murine macrophage cytolytic factor by drugs inhibiting DNA, RNA, and protein synthesis. 346 37


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