Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006826 (cancer)
 1,092,456 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In view of cellular adoptive immunotherapy we have studied monocyte-mediated cytostasis and cytotoxicity against U 937 cells, a human histiocytic lymphoma cell line. Highly purified human monocytes and monocyte-derived macrophages were activated with interferon gamma (IFN) or tumour necrosis factor alpha (TNF) to antileukemic immune effector cells. Antileukemic activity of human monocytes was dependent on monocyte differentiation into macrophages and on a dose- and time-dependent activation with IFN or TNF. Maximum cytostasis of 97.0 +/- 0.7% (mean +/- SEM) (conventional [3H]dT uptake assay) and 81.9 +/- 5.3% cytotoxicity (modified MTT assay) of U 937 cells was obtained by monocytes activated with 100 U/ml IFN for at least 24 h at an effector-to-target-cell ratio of 10. U 937 cells premodified with IFN showed an increase in susceptibility to monocyte-mediated cytotoxicity. U 937 cells premodified with TNF were almost resistant to monocyte-mediated cytotoxicity while activated monocytes maintained their cytotoxic potential. These data show that IFN and TNF are potent activators of monocyte-mediated cytotoxicity. Furthermore, IFN and TNF might be involved in the regulation of the susceptibility of leukemic cells to lysis by interactions with monocytes or macrophages.
Cancer Immunol Immunother 1992
PMID:Role of interferon gamma and tumour necrosis factor alpha in monocyte-mediated cytostasis and cytotoxicity against a human histiocytic lymphoma cell line. 156 17

Decreased activity of hypoxanthine-guanine phosphoribosyl-transferase (HGPRT), responsible for the conversion of 6-mercaptopurine and 6-thioguanine (6-TG) to their cytotoxic nucleotides, may cause resistance to these thiopurines in experimental leukemic systems. The clinical significance of this mechanism is as yet unclear. In 83 children with untreated acute lymphoblastic leukemia (ALL), we determined the prognostic value of HGPRT activity and the relation between HGPRT activity and resistance to thiopurines. HGPRT activity was determined radiochemically; in vitro resistance to 6-TG with the MTT assay. HGPRT level was significantly lower in T-ALL than in B-lineage ALL; no differences were found between sequential differentiation stages of B-lineage ALL. HGPRT activity was inversely related to the white-blood-cell count (WBC). Among patients with cALL and pre-B-ALL with WBC less than 50 x 10(9)/l, cases with a low HGPRT had a significantly poorer prognosis than those with a high HGPRT. WBC, age, sex, organomegaly and differentiation stage were comparable in both patient groups. No correlation was found between HGPRT activity and in vitro 6-TG resistance in cALL and pre-B-ALL patients. T-ALL cases were not more 6-TG-resistant than cALL and pre-B-ALL cases. Cells from 6 relapsed ALL cases did not show decreased HGPRT activity. We conclude that: (a) HGPRT is lower in T- than in B-lineage ALL and is constant in sequential differentiation stages of B-lineage ALL; (b) HGPRT activity is inversely related to tumor load; (c) low HGPRT activities are correlated with a poorer prognosis in precursor B-ALL but this cannot be explained by thiopurine resistance because (d) there is no relation between HGPRT activity and in vitro 6-TG resistance.
Int J Cancer 1992 May 08
PMID:Hypoxanthine-guanine phosphoribosyl-transferase in childhood leukemia: relation with immunophenotype, in vitro drug resistance and clinical prognosis. 156 89

We compared in vitro the cytotoxic activity of vinorelbine (VRB) (Navelbine, 5'-nor-anhydro-vinblastine) a novel Vinca alkaloid, with that of vinblastine (VBL) vincristine (VCR) and vindesine (VDS). Five continuous human melanoma cell lines (C32, G361, StMl11a, StMl12d and StMl14a) and a new line WHMel 1, were used in this study. In growth-inhibition assays, VDS and VRB exhibited comparable cytotoxicity against the C32 and G361 melanoma lines; the effect being dose- and time-dependent. VRB appeared less inhibitory compared to VDS in the lowest concentrations (0.1-1 nM). The same activity was observed with 0.1-1 microM. These drugs exhibited comparable growth inhibition at clinically achievable doses. The MTT assay was used to compare VBL, VCR, VDS, and VRB. Overall IC50 values (concentration required to reduce viability by 50%) ranged from 1 pM to 10 nM. The reduction in cell viability with VRB was similar to that observed with the reference drugs in four out of five lines tested by this method. However a trend was observed for IC50 values to be lower with VBL and VDS. In clonogenic assays (StMl11a, StMl12d and StMl14a lines, 1 h exposure) VRB and VDS produced the same reduction in survival. Survival curves were exponential followed by a terminal plateau. IC50 values ranged from 60 nM to 70 nM. Our results indicate that VRB has in vitro activity against six melanoma lines with differing phenotypic characteristics.
J Cancer Res Clin Oncol 1992
PMID:Antiproliferative activity of vinorelbine (Navelbine) against six human melanoma cell lines. 157 45

The in vitro sponge-gel-supported three-dimensional histoculture chemosensitivity assay (Hoffman assay) allows the in vivo-like culture of human tumors. In this study, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) end point was applied to the Hoffman assay in an attempt to increase in vitro-in vivo correlation. The chemosensitivities of 16 human tumor lines were determined in vitro by the histoculture assay, and retrospectively correlated to their in vivo chemosensitivity as xenografts in nude mice. The in vitro test was considered to be positive if tumor-cell MTT reduction activity was lowered by more than 50%. The cutoff drug concentrations to determine sensitivity in vitro were determined for mitomycin C, doxorubicin, 5-fluorouracil and cisplatin. Using these cutoff drug concentrations in vitro we found, as a function of time of exposure, a strong correlation between serum drug concentrations found in nude mice given maximum tolerated doses and drug concentrations found in the histoculture media in vitro, thereby establishing a relationship between the amounts of drugs to which tumors were exposed in vivo and in vitro. The overall correlation rate of the efficacy results of the drug-response assay to in vivo chemosensitivities was 89.8%, with 90.0% true-positive and 89.7% true-negative rates, 81.7% sensitivity and 94.6% specificity, thereby indicating potential clinical use for tumor histoculture with the MTT end point.
Int J Cancer 1992 May 28
PMID:High in vitro-in vivo correlation of drug response using sponge-gel-supported three-dimensional histoculture and the MTT end point. 159 40

Physalin F and physalin D were isolated and characterized from the ethanolic extract of the whole plant of Physalis angulata L. (Solanaceae). Systematic fractionation of the ethanolic extract of the plant led to characterization of physalin F from the fraction PAIV-2 as an active ingredient which showed cytotoxicity in vitro by DEA and MTT assays on 8 cancer cell lines, five human cancer cell lines: HA22T(hepatoma), HeLa(cervix uteri), KB(nasopharynx), Colo-205(colon) and Calu-1(lung); and three animal cancer cell lines: H1477(melanoma), Hep-2(laryngeal) and 8401(glioma). It was found that the anti-hepatoma action is the strongest, and the anti-HeLa is the next. Physalin F also had an antitumor effect in vivo against P388 lymphocytic leukemia in mice whereas physalin D was inactive both in vitro and in vivo.
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PMID:Antitumor agent, physalin F from Physalis angulata L. 162 43

The potentiation of anticancer agents by non-anticancer drugs is one of the possible strategies for overcoming cellular resistance to chemotherapy. In order to overcome cis-diamminedichloroplatinum(II) (CDDP) resistance, we evaluated the sensitizing effect on CDDP-induced cytotoxicity of various non-anticancer agents which might alter membrane transport, by means of a colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Drugs which have previously been demonstrated to modify multidrug resistance did not show a sensitizing effect to cisplatin. Only amphotericin B (AmB) selectively conquered CDDP resistance in the CDDP-resistant cell line. A drug accumulation study done by the atomic absorption method demonstrated that the accumulation of CDDP in the resistant cell line recovered to the level of the parental cell line after treatment with AmB. Thus, AmB might overcome CDDP resistance by increasing the accumulation of CDDP.
Jpn J Cancer Res 1991 Jun
PMID:Reversal of cisplatin resistance with amphotericin B in a non-small cell lung cancer cell line. 164 14

The extract from the mycelium of Ganoderma lucidum was diluted into serial concentrations and added into in vitro cultured oral cancer and normal cell lines. After incubation for 24 hours, the survival fraction was determined by MTT colorimetric assay. The result revealed that the ID50 was about 3mg/ml and the total lethal dosage was beyond 4 mg/ml. This toxic effect was the same in both cancer and normal cells. Not only was there no difference between cancer and normal cells, but also the high dosage required in toxicity leads to the conclusion that the GL has no direct cytotoxic effect in cancer treatment.
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PMID:[In vitro cytotoxicity of Ganoderma lucidum on oral cancer cells]. 165 94

The present study was designed to analyse the cytotoxic effects of the combination of fotemustine with 5-fluorouracil (5-FU) plus folinic acid (FA). Two human tumor cell lines were used; one line was derived from colon cancer (WIDR) and the other, from a non-small-cell lung cancer (CAL 12). Cytotoxic effects were assessed using the MTT (tetrazolium bromide) semi-automated test in 96-well incubation plates. The effects of various drug combinations were evaluated by the isobologram method. The drug combinations tested included fotemustine concentrations of 20, 30, 40, 50 and 70 micrograms/ml, 5-FU concentrations of 5, 15 and 30 micrograms/ml, and a constant FA concentration of 10(-5) M. A total of 180 different experimental conditions were tested. When cells were exposed to fotemustine prior to treatment with 5-FU, the final cytotoxic effects on both cell lines were additive or synergistic in the majority of cases (P less than 0.001). The 5-FU concentration was a determinant factor that modified the effects of the drug combination from antagonism (at low 5-FU concentrations) to synergism (high 5-FU concentrations; P less than 0.001). The addition of FA (10(-5) M) resulted in a significant shift towards synergistic associations in both cell lines. Administration of 5-FU prior to treatment with fotemustine caused marked antagonism, which 10(-5) M FA could not significantly shift towards simple additivity.
Cancer Chemother Pharmacol 1991
PMID:Sequence-dependent cytotoxic effects of the combination of a new nitrosourea, fotemustine, with 5-fluorouracil plus folinic acid. 165 24

FK973 (11-acetyl-8-carbamoyloxymethyl-4-formyl-14-oxa-1, 11-diazatetracyclo [7.4.1.0.0] tetradeca-2, 4, 6-trien-6, 9-diyl diacetate), an analogue of mitomycin C (MMC), was tested against human oral squamous cancer cell lines Ca 9-22, HSC-2, HSC-3, breast adenocarcinoma cell lines MCF-7, BT-20 and breast ductal carcinoma cell line T-47D using MTT assay. FK973 showed cytotoxic effects against six tested cell lines and much wider effective dose range than MMC, adriamycin (ADM), and cisplatin (CDDP). FK973 was the most potent of the four drugs tested against the growth of the three squamous cancer cell lines derived from oral cavity. However, in breast cancer cell lines, FK973 was less potent than MMC and ADM. FK973 was time and dose dependent. The combination effects of FK973 with 5-Fluorouracil (5FU) or CDDP were synthetical. It may be a promising candidate for the treatment of oral and breast cancer.
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PMID:Cytotoxic activity of FK973 against human oral and breast cancer cells. 166 Dec 25

The combination of radiotherapy and cytostatic drugs is of interest in the treatment of several solid tumors. In these preclinical investigations we tested whether ifosfamide and ACNU are able to enhance radiation effects. The experiments were performed by using the MTT assay. Two small cell and 2 non small cell lung cancer cell lines were involved. Ifosfamide, ACNU or both drugs together were tested in 6 different concentrations adjusted to the peak blood level. During the 1 hour drug incubation time, the cell lines were either irradiated with a single dose of 4 Gy or not. The main results were that ACNU possessed only little cytostatic activity in the cell lines under examination. In contrast, ifosfamide caused a dose related cytostatic activity in all cell lines. Concentrations of 26 micrograms/ml (NCC-SCLC H 82) or 10-12 micrograms/ml (3 other cell lines) were able to reduce the surviving cell fraction to less than 50% (IC50). While ACNU showed no clear outlined radiosensitizing properties, ifosfamide reinforced the radiation effects in 3 out of 4 cell lines indicating radiosensitizing properties of this drug. Synergistic effects of ifosfamide and ACNU have not been noticed. These preclinical investigations may constitute the basis for combined ifosfamide and irradiation therapy in future clinical trials.
J Cancer Res Clin Oncol 1991
PMID:Combined chemo- and radiosensitivity testing with ifosfamide and ACNU in human lung cancer cell lines. 166 91


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