Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0149925 (small cell lung cancer)
6,491 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anthracyclines possessing either a 9-alkyl modification in the A-ring of the tetracyclic aglycone and/or specific changes to the amino sugar moiety retain effective cytotoxic activity against multidrug resistant (MDR) cell lines. To obtain a better understanding of the structural features responsible for this potentially valuable behaviour, we used the MTT tetrazolium dye reduction assay to calculate resistance factors (RF = the ratio of ID50 for the drug-resistant line to that for the parental line) for the EMT6/P mouse mammary tumour and its MDR variant EMT6/AR1.0, and the H69/P human small cell lung cancer line and its MDR counterpart H69/LX4. Both MDR lines exhibit marked resistance to doxorubicin, MDR 1 gene amplification, hyperexpression of the membrane P-glycoprotein and reduced drug accumulation. RF values for doxorubicin were 34 and 131 in the EMT6 and H69 cell line pairs, respectively. The 9-alkyl-substituted anthracyclines were confirmed as having RF values 9- to 15-fold lower than those for doxorubicin. The 9-ethyl analogues Ro 31-1966 (RF for EMT6 2.2, RF for H69 4.7) and Ro 31-1749 (RF for EMT6 3.9, RF for H69 9.5) were superior to the previously studied 9-methyl analogue Ro 31-1215 (RF for EMT6 8.1 RF for H69 12.4). A clear trend for RF values to decrease with increasing 9-alkyl chain length was also noted in the structurally more complex aclacinomycin series. For example, 13-methyl-aclacinomycin (RF for EMT6 1.0, RF for H69 2.2) featuring a 9-isopropyl moiety was superior to the 9-alkyl-containing aclacinomycin A (RF for EMT6 4.7, RF for H69 5.8), and this was in turn more effective than the 9-methyl analogue sulfurmycin A (RF for EMT6 6.4, RF for H69 14.2). The trisaccharide moiety was not an essential feature for activity against MDR lines in the aclacinomycins, as shown by the low RF value with aklavine (RF for EMT6 2.1, RF for H69 2.5). However, a small change in one of the sugar moieties of aclacinomycin A, as in marcellomycin, resulted in a considerable increase in RF values (RF for EMT6 18.5, RF for H69 25.3). The complex anthracyclines AD 32 (RF for EMT6 6.5, RF for H69 11.7) and particularly tetrahydropyranyl-doxorubicin (RF for EMT6 1.4, RF for H69 3.2) were effective against MDR lines.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Further examination of 9-alkyl- and sugar-modified anthracyclines in the circumvention of multidrug resistance. 133 31

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.
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PMID:Combined chemo- and radiosensitivity testing with ifosfamide and ACNU in human lung cancer cell lines. 166 91

A simple colorimetric test, the MTT assay, has been adapted for chemosensitivity testing of human small cell lung cancer cell lines, and fresh tumour samples. Optimal conditions for clinical chemosensitivity testing were determined using established SCLC lines. Nineteen different chemotherapeutic agents were tested, and sixteen of them were found to be cytotoxic in this assay system. The drug sensitivity of a panel of 16 SCLC cell lines was measured and compared. There was very little intraexperiment variation, but the interexperiment variation was significant. Cell lines which were derived from patients who had not received chemotherapy at the time the cell line was established were more sensitive (to all but one of the drugs) than lines derived from treated patients, and the differences were statistically significant for two of the drugs. One cell line, NCI-H209, which was derived from an untreated patient, stood out as being the most sensitive or among the most sensitive to all of the drugs tested. Another cell line, H69AR, which is a multidrug resistant subline of the cell line NCI-H69, was the most resistant to many of the natural product drugs tested. Multiple drug chemosensitivity testing was performed on eight fresh tumour samples from SCLC patients (five pleural effusions, one lymph node, and two primary tumours). It was possible to perform chemosensitivity testing on all of the clinical samples in which sufficient tumour cells were available. The drug sensitivity of the clinical samples was, in most cases, within the same range as for the cell lines. Since this assay is very rapid and simple to perform, it may have practical applications in clinical drug sensitivity testing of human tumours.
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PMID:Chemosensitivity testing of small cell lung cancer using the MTT assay. 184 54

In vitro drug sensitivity testing (DST) of long-term cultures from small cell lung cancer (SCLC) tumours was correlated with response and survival after four cycles of etoposide and cisplatin. 27 cell lines from 25 patients were tested by the semi-automated MTT assay after a median culture of 29 months. The logs of the IC50 concentrations for etoposide and cisplatin were correlated with each other. For both drugs, median IC50 values of patients with partial or complete responses ("responders") were significantly lower (7-8 fold) than those of non-responders. When survival was plotted according to whether drug IC50 values were in the upper or lower halves, curves for etoposide were significantly different, but those of cisplatin were not. DST of the long-term cell lines by MTT assay was significantly correlated with the Weisenthal dye exclusion assay of earlier passages of the same cell lines. DST of long-term SCLC cultures can predict clinical response and, for etoposide, survival. Disease-oriented panels of carefully selected, continuous, human tumour cell lines can be used to screen new drugs.
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PMID:Correlation of in vitro drug sensitivity testing of long-term small cell lung cancer cell lines with response and survival. 196 47

The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) hybrid assay was developed by technically combining the human tumor clonogenic assay and the MTT assay to make the most of both assays. This assay was able to estimate the in vitro growth of cultured cell lines and of tumor cells in pleural effusion, suggesting the possibility of its use for assessment of chemosensitivity and radiosensitivity of fresh tumor samples. Multiple cell lines [including morphological and/or phenotypical in vitro converters and cisplatin (CDDP)-resistant lines] were established from three patients with small cell lung cancer at different stages of the disease. Chemosensitivity of these cell lines to four commonly used chemotherapeutic drugs was tested by the MTT hybrid assay. SK1 and SK3 lines were established from Patient S. K. before and after chemotherapy and radiotherapy, respectively. SK3/CDDP, a CDDP-resistant line derived from the SK3 line, was 30-fold more resistant to CDDP [50% inhibiting dose (IC50), 21.5 micrograms/ml] than the SK1 line. In Patient M. O., MOA2/CDDP, a CDDP-resistant line derived from MOA2 (an in vitro converter from the MO line), was 41-fold more resistant to CDDP (IC50, 37 micrograms/ml) than the parent MO line. From Patient T. M., TM1 and TM2 lines were established before and after chemotherapy, respectively. The latter showed 6-fold more resistance to CDDP than the former. Chemosensitivity of these lines to three other drugs, 4-hydroperoxycyclophosphamide, Adriamycin, and etoposide, suggested cross-resistance between CDDP and 4-hydroperoxycyclophosphamide. Radiosensitivity study was also carried out with the MTT hybrid assay. The MOA2 line was more resistant [Do, 3.0 Gy; extrapolation number (n), 4.0] than the parental MO line (Do, 1.6 Gy; n, 2.1). There was no clear difference in radiosensitivity between the cell lines established before and after radiation therapy in Patient S. K.
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PMID:Chemosensitivity and radiosensitivity of small cell lung cancer cell lines studied by a newly developed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) hybrid assay. 254 17

Thirty human lung cancer cell lines were tested for chemosensitivity using the semi-automated, non-clonogenic MTT assay. The tumour cell lines came from three major categories of patients: untreated small cell lung cancer (SCLC); SCLC relapsing on chemotherapy; and non-SCLC predominantly from untreated patients. From these data IC50 values were derived for each drug in each cell line. While some inter-experimental variability was observed, the rank order of chemosensitivity of each cell line within this panel was significantly correlated between experiments. These results show that tumour cell lines derived from untreated small cell lung cancer patients were the most chemosensitive for adriamycin, melphalan, vincristine and VP16 compared to the other cell types. In addition, untreated SCLC was more sensitive than non-SCLC to BCNU and cis-platin, while vincristine was the only drug to which treated SCLC was more sensitive compared to the non-SCLC lines. In contrast, no significant differences between the lung cancer types were observed for vinblastine. Thus, this panel of lung cancer cells exhibited a drug sensitivity profile paralleling that observed in clinical practice. These results suggest that this lung cancer cell line panel in combination with a relatively simple but reproducible chemosensitivity assay, such as the MTT assay, has potential for the testing of drug combinations and evaluating new anti-cancer agents in vitro.
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PMID:Chemosensitivity testing of human lung cancer cell lines using the MTT assay. 284 61

Seven small- (SCLC) and four non-small-cell (NSCLC) lung cancer cell lines were used to examine the in vitro cytotoxicity of cytotoxic drugs such as (1aS-(1a alpha,8 beta,8a alpha,8b alpha]-8-[aminocarbonyl)oxy)methyl)-4,8a- dimethoxy-1,1a,2,8,8a,8b-hexahydro-7-hydroxy-5-methyl-6- nitrosoazirino(2',3':3,4)-pyrrolo-(1,2-a)indole (RM-49) and 11-acetyl-8-carboxymethyl-4-formyl-14oxa-1,11-diaze- tetracyclo(7.4.1.0(2,7),0(10,12]tetradeca-2-4-6-trien-6,9-++ +diyl-diacetate (FK973). In vitro cytotoxicities of RM-49 and FK973 were compared with those of mitomycin C (MMC), cisplatin (CDDP), carboplatin (CBDCA), etoposide (VP16), adriamycin (ADM) and vindesin (VDS). Drug sensitivity was determined using a tetrazolium (MTT)-based assay. Average IC50 values of these two drugs were not statistically different compared with that of MMC, although FK973 showed strong antitumor activity against SCLC cell lines such as LT3, N857, and H69 at the same concentration. The predicted peak plasma concentration (predicted PPC) calculated by the formula proposed by Scheithauer, log (predicted PPC) = -0.788 + (0.755 x log(LD50], and relative antitumor activity, RAA (PPC/IC50), of RM-49 were higher than those of other drugs such as MMC, CDDP, CBDCA, and ADM against SCLC cell lines (P less than or equal to 0.05), and those of FK973 were also higher than those of other drugs such as MMC, CDDP, CBDCA, and ADM against SCLC cell lines (P less than or equal to 0.05). Based on these promising in vitro studies, the clinical trials of RM-49 and FK973 were warranted.
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PMID:In vitro antitumor activity of mitomycin C derivative (RM-49) and new anticancer antibiotics (FK973) against lung cancer cell lines determined by tetrazolium dye (MTT) assay. 284 80

A semiautomated colorimetric assay (MTT assay), based on the ability of live cells to reduce a tetrazolium-based compound, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), to a purplish colored formazan product that can be measured spectrophotometrically, has recently been adapted for use in drug sensitivity analysis of cultured human tumor cell lines. We report the application of this assay for the evaluation of the growth factor requirements of human small cell lung cancer (SCLC) cell lines. Specifically, the growth stimulation of each constituent of a previously reported serum-free defined medium system for SCLC including various concentrations of hydrocortisone, insulin, transferrin, 17 beta-estradiol, and selenium (HITES) was evaluated. The optimal concentrations for insulin, transferrin, and selenium derived in the previously reported experiments with direct counting of viable cells were similar to optimal concentrations determined for the growth of three SCLC cell lines (NCI-H82, NCI-N417, NCI-H526) using the MTT assay. In contrast to the previous report, the growth-stimulating effects of hydrocortisone and 17 beta-estradiol were negligible. Using the MTT we have shown that a SCLC cell line, NCI-H345 (which has been previously reported to produce a transferrin-like molecule), was growth-inhibited by an anti-transferrin receptor antibody, when grown in transferrin-free media. The conditioned media from this cell line is stimulatory to other transferrin-sensitive cell lines, suggesting the possibility of an autocrine role for this transferrin-like molecule at least in that cell line. With carefully defined conditions for a given cell line in which cell density and other parameters are within a range of constant MTT metabolism, the assay is well suited for precise analysis of growth factor effects.
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PMID:Growth factor effects on small cell lung cancer cells using a colorimetric assay: can a transferrin-like factor mediate autocrine growth? 284 78

In order to analyze the presence and the function of the "insulin-like growth factor I (IGF-I) system" in human non-small-cell lung cancer (N-SCLC) we tested 5 cell lines of different histological sub-types: A549, Ca-Lu-6, SK-Lu-1 (adenocarcinoma); Ca-Lu-1, SK-Mes-1 (squamous carcinoma) and one normal fibroblast-like fetal lung cell line (IMR-90) for expression of the IGF-I peptide and its RNA transcribed from the IGF-I gene; IGF-binding proteins (IGF-BP); IGF-I receptor (IGF-I-R) and its mRNA. In addition, we examined the capacity of exogenous human recombinant IGF-I to enhance the in vitro cell proliferation. In medium conditioned from cell cultures, we detected immunoreactive IGF-I material by radioimmunoassay. Western ligand blot and affinity labelling demonstrated the presence of several molecular species of IGF-BPs (IGF-BP-4, -1, -2, -3) as well. Northern blot analysis of polyA+ RNA from all cell lines examined revealed the presence of IGF-I and IGF-I-R mRNA. Moreover, binding studies on cultured cell lines showed one class of high-affinity, operative type-I IGF cell-surface binding sites. Finally, by thymidine uptake and colorimetric metabolic MTT assays, we found that most neoplastic cell lines react mitogenically to IGF-I and that its physiological effect is abolished by an anti-IGF-I-receptor antibody. These data indicate the importance of the IGF-I system in N-SCLC growth. Furthermore, they suggest that this mitogenic complex should be appraised as a possible target for anti-neoplastic drugs, antibodies or growth-factor analogues offering potential new approaches to therapy.
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PMID:Expression and function of the insulin-like growth factor I system in human non-small-cell lung cancer and normal lung cell lines. 750 79

Previously, we showed that in vitro resistance to daunorubicin (DNR) at initial diagnosis was related to a poor long-term clinical outcome in childhood acute lymphoblastic leukemia (ALL), and that cells of relapsed ALL were in vitro more resistant to DNR than cells of untreated ALL. Topoisomerase II (Topo II) is an intracellular target for anthracyclines and epipodophyllotoxins. Decreased levels and/or activity of Topo II have been associated with multidrug resistance in cell lines. We investigated Topo II alpha gene expression in fresh leukemic samples from 19 children with untreated and 14 children with relapsed ALL using a sensitive RNase protection assay. The in vitro cytotoxicity of the Topo II inhibitors DNA and teniposide (VM26) was measured using the MTT assay, and the cell cycle distribution of leukemic samples was analyzed by DNA flow cytometry. Results showed that (1) relapsed ALL samples were more resistant to DNR, but not to VM26 compared to untreated samples; (2) large interpatient variations existed in both Topo II alpha gene expression and in vitro cytotoxicity results; (3) Topo II alpha gene expression was detectable in 29/33 childhood ALL samples with a median expression of 5% the level of a relatively chemosensitive human small cell lung cancer cell line; (4) Topo II alpha gene expression did not differ between untreated and relapsed ALL; (5) Topo II alpha gene expression was positively correlated with the percentage of ALL cells in S- and G2M-phase, but not with the in vitro cytotoxicity of the drugs tested. In conclusion, resistance to DNR in childhood ALL can not be explained by decreased levels of Topo II alpha gene expression, but additional Topo II activity studies in fresh leukemia samples may need further exploration.
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PMID:Topoisomerase II alpha gene expression in childhood acute lymphoblastic leukemia. 756 5


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