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 chemosensitivity test (MTT assay) was conducted using 59 fresh surgical specimens collected from Keio University, Kitasato Institute Hospital and 14 affiliated hospitals, in order to assess the specimen transfer system and the reproducibility of the assay results obtained at Keio University and Kitasato Institute Hospital. Although the optical density yielded by the tumor cells in a number of 5 x 10(4)/well and the number of evaluable cases were significantly reduced through the transfer, the chemosensitivity pattern of the specimen was identical before and after the transfer. Fifty seven of 59 cases were evaluable and the concordant rate of the assay results between the two institutes was 80.6% (108/134) among each case-drug combination. Since the transfer system of the specimen was established and the reproducibility of the assay results in two institutes was confirmed, the "test center" method of the MTT assay appears to be possible by collecting the surgical specimens from the affiliated hospitals.
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PMID:[MTT assay using fresh surgical specimens with reference to the transfer system and reproducibility in "test center" method]. 222 25

In vitro thermosensitivity of various human tumors including 90 esophageal, 10 gastric and 40 colo-rectal cancers were evaluated using the succinate dehydrogenase inhibition (SDI) test. Tumor fragments minced with scissors were incubated at 43 degrees C as heat treated cells and at 37 degrees C as controls for 20 hrs, and assayed for the succinate dehydrogenase (SD) activity using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. The thermosensitivity was estimated by the percentage of SD activity of heat treated cells compared to that of each control. A variation in the thermosensitivity was noted between patients. The SD activity was 60.1 +/- 20.3% (mean +/- standard deviation) for esophageal cancers, 34.9 +/- 21.7% for gastric cancers, 50.3 +/- 20.6% for colo-rectal cancers. Significant differences were noted between esophageal cancers and gastric cancers, colo-rectal cancers (p less than 0.01 and p less than 0.05, respectively). When the thermosensitivity was arbitrarily defined as reduction in the SD activity to 50% of control or less, the positive rates were 31.1% for esophageal cancer, 70% for gastric cancer and 62.5% for colo-rectal cancer. Our results show that the SDI test is a useful method for determination of the thermosensitivity of clinical samples.
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PMID:[In vitro thermosensitivity of various human tumors evaluated using the SDI (succinate dehydrogenase inhibition) test]. 223 61

Chemosensitivity assays including colony forming assay (CFA), MTT dye reduction assay (MTT assay) and thymidine incorporation assay (TIA) for cultured rat and human glioma cells were conducted to determine the correlation among them and the in vivo antitumor efficacy of anticancer drugs using rats implanted glioma cells. Cytotoxicity of various agents such as ACNU, ACR, CDDP, VCR or BLM, was estimated from the concentrations which caused 50% inhibition of the cell growth at the peak plasma concentration. The survival time of tumor bearing rats was assessed after ip treatment with these agents at their estimated clinical doses. This parameter was greater in the drugs that were shown to be highly sensitive in CFA and was consistent with the data for CFA. In the chemosensitivity assays, CFA closely correlated to MTT assay for all agents except VCR, but poorly so to TIA. The results in this study indicate that MTT assay seemed to be useful for determining the chemosensitivity of anticancer drugs and that chemosensitivity assay should be conducted depending on the nature of anticancer drug.
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PMID:[Chemosensitivity assays for malignant gliomas]. 224 Nov 89

The chemosensitivity was evaluated by the in vitro succinate dehydrogenase inhibition (SDI) test in 1,000 human tumors including 237 gastric cancers, 116 colorectal cancers, 113 hepatoma and 534 others. These tumor cells were exposed to 5 kinds of antitumor drugs, carboquone (CQ), adriamycin (ADM), mitomycin C (MMC), aclacinomycin A (ACR), cis-platinum (DDP). After exposure to the antitumor drugs, cell viability was assessed with colorimetric assay, based on the ability of succinate dehydrogenase (SD) in living tumor cells to reduced a tetrazolium (MTT) to a formazan. The chemosensitivity was determined to be positive when the SD activity of drug exposed cells decreased to below 50% of that of control cells, on day 3 of exposure. The chemosensitivity varied in the tumor tissues. The chemosensitivity of metastatic lesions of lymph nodes were higher than that of the primary lesions, while metastatic liver tumors had lower sensitivity than the primary lesions. The intra-tumorous distribution of SD activity in 12 human gastric cancers were compared with normal adjacent tissues using histochemistry. Seventy-five % (9/12) of gastric cancer tissues had higher SD activity than normal adjacent tissues. The SDI test is rapid and simple method to predict the sensitivity test of various human tumors to antitumor drugs.
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PMID:[The sensitivity of 1,000 human tumors to antitumor drugs using the succinate dehydrogenase inhibition (SDI) test]. 227 70

Four structural analogs of benzoporphyrin derivative (BPD) have been studied and compared for photosensitizing activity in vitro. All analogs have an identical reduced tetrapyrrol porphyrin ring, and differ by the position of a cyclohexadiene ring (fused at either ring A or ring B of the porphyrin) and the presence of either two acid groups or one acid and one ester group at rings C and D of the porphyrin. Photosensitizer activity was tested with the M1 tumor cell line using an assay (the MTT assay) which detects mitochondrial hydrogenases as a measure of cell viability. This assay was shown to be equivalent to the standard clonogenicity or [3H]thymidine uptake assay. Comparative studies with the BPD analogs showed that the monoacid derivatives had equivalent cytotoxicity and were about five-fold more active than the diacid forms. This was the case whether the assays were performed in the presence or absence of fetal calf serum.
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PMID:In vitro evaluation of phototoxic properties of four structurally related benzoporphyrin derivatives. 228 43

Though various chemotherapy protocols lead to considerable response rates in squamous cell head and neck cancer (SCHNC), the overgrowth of a tumor cell phenotype which no longer responds to clinically achievable drug concentrations regularly impairs definite tumor control. In order to investigate mechanisms of drug resistance towards one of the most active agents in SCHNC we established four Cisplatin (CDDP)-resistant sublines (DDP1-DDP4) of the recloned human SCHNC cell line HLac 79. The 50% inhibitory drug concentration (IC50) of CDDP as determined by the colorimetric MTT-assay was increased by the factors 2.7 (DDP1), 3.3 (DDP2), 5.1 (DDP3), and 6.4 (DDP4) in the respective sublines. Three subpopulations contained significantly elevated glutathione (GSH) levels by the factors 1.4 (DDP3), 1.7 (DDP2), and 2.4 (DDP4) compared to the maternal line (50.2 nM/mg protein). DDP4 showed increased activity of gamma-glutamyl-transpeptidase (1.83 vs. 1.21 mU/mg protein), and DDP2 and DDP4 showed increased activity of GSH-S-transferase (35.6 and 51.9 vs. 25.1 mU/mg protein). Concerning both GSH-peroxidase and GSH-reductase no significant differences between the HLac 79 subpopulations were observed. Intracellular CDDP accumulation determined by neutron activation analysis revealed reduced drug uptake in DDP3 and DDP4 (60% and 76% of control value).
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PMID:Establishment and characterization of cisplatin-resistant sublines of the human squamous carcinoma cell line HLac 79. 228 22

Three human tumor cell lines of widely differing radiosensitivity were used to examine the characteristics of the 3-[4,5-dimethyl(thiazol-2-yl)-3,5-diphery]tetradium bromide (MTT) assay and to select suitable conditions for its use in assessing the response of cells to ionizing radiation. The optimal concentration of MTT and the time of incubation of the cells with MTT were individualized for each cell line. The relationship between absorbance and cell number was not linear over the wide range of cell numbers that were used. A calibration curve of absorbance against cell number for each cell line was therefore used. Using the assay to quantify metabolically viable cells, growth curves of irradiated and unirradiated cells were constructed on days 0-14 after irradiation. Accurate surviving fractions could be calculated only when cells were in exponential growth. Using this modification to its interpretation, the MTT assay was able to provide a reproducible measure of survival, which compared well with clonogenic cell survival measurements. However, the necessity to optimize conditions of the MTT assay for each cell line severely limits its usefulness in determining the radiosensitivity of cells in primary human tumor cultures.
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PMID:Use of the tetrazolium assay in measuring the response of human tumor cells to ionizing radiation. 230 4

The succinate dehydrogenase inhibition (SDI) test was used for determining chemosensitivity of various human tumors. This test was based on the correlation between the cellular succinate dehydrogenase activity as determined by 3-(4,5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT), and cell viability. The chemosensitivity varied in the tissue. Some factors are involved in the chemosensitivity, that is origin of a tumor, tissue differentiation and tissue DNA synthetic activity. This test is a convenient method for clinical use and provides important information about chemosensitivity.
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PMID:[In vitro chemosensitivity test: succinate dehydrogenase inhibition (SDI) test]. 230 18

A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay was developed and compared with 51Cr release from different adherent tumor cell targets (human squamous cell carcinoma lines of the head and neck established in our laboratory, melanoma, and colorectal carcinoma) using 5-7-day human lymphokine-activated killer cells and monocyte-depleted peripheral blood lymphocytes as effectors. With adherent tumor cell targets, MTT colorimetry was more sensitive than the 51Cr release assay in measuring the antitumor activity of effectors: median, 4385 (range, 988-8144) versus median, 1061 (range, 582-7294) lytic units (the number of effector cells required to lyse 20% of 5 x 10(3) targets)/10(7) effectors (P less than 0.01). Background effects (without effector cells) were comparable in 4-h assays (9% versus 10%) between MTT colorimetry and 51Cr release. In 24-h assays, MTT colorimetry showed higher antitumor activity (70-100% versus 40-60% lysis at 1:1 effector:target cell ratio) but lower background effects (6% versus 38%) than 51Cr release assay. Thus, MTT colorimetry was more sensitive, did not use radiolabeled targets, required fewer effector cells, and was easier, less expensive, and better adaptable to serial monitoring of effector cell function in cancer patients. This colorimetric assay is especially well suited to adherent tumor cell targets. The use of adherent tumor cell monolayers, as opposed to trypsinized single cell suspensions, provides an opportunity to measure interactions of effector cells with enzymatically unaltered solid tumor targets. Because of the greater sensitivity of the colorimetric assay, the transformation of MTT data into lytic units, as commonly used for 51Cr release assays, required an adjustment to avoid the extrapolation based on the exponential fit equation.
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PMID:Evaluation of tetrazolium-based semiautomatic colorimetric assay for measurement of human antitumor cytotoxicity. 234 May 18

The National Cancer Institute (NCI) is implementing a large-scale in vitro drug-screening program that requires a very efficient automated assay of drug effects on tumor cell viability or growth. Many laboratories worldwide have adopted a microculture assay based on metabolic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). However, because of certain technical advantages to use of the protein-binding dye sulforhodamine B (SRB) in a large-scale screening application, a detailed comparison of data generated by each type of assay was undertaken. The MTT and SRB assays were each used to test 197 compounds, on simultaneous days, against up to 38 human tumor cell lines representing seven major tumor categories. On subsequent days, 38 compounds were retested with the SRB assay and 25 compounds were retested with the MTT assay. For each of these three comparisons, we tabulated the differences between the two assays in the ratios of test group values to control values (T/C) for cell survival; calculated correlation coefficients for various T/C ratios; and estimated the bivariate distribution of the values for IC50 (concentration of drug resulting in T/C values of 50%, or 50% growth inhibition) for the two assays. The results indicate that under the experimental conditions used and within the limits of the data analyses, the assays perform similarly. Because the SRB assay has practical advantages for large-scale screening, however, it has been adopted for routine use in the NCI in vitro antitumor screen.
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PMID:Comparison of in vitro anticancer-drug-screening data generated with a tetrazolium assay versus a protein assay against a diverse panel of human tumor cell lines. 235 37


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