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Query: UMLS:C0276241 (MCF)
 28,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MCF-7 and HT-29 cell lines were selected as a reliable model to examine the possible parameters affecting the sensitivity of tumour cells to photodynamic therapy (PDT) using a dye-laser at 630 nm. The chemical composition of haematoporphyrin derivative (HPD) was determined by high-performance liquid chromatography (HPLC) analysis and was in agreement with reported values. MTT assays were performed to assess the time-dependency of PDT and the influence of the output power and light fluence. The results showed a maximal cytotoxicity 48 h after photoirradiation. The output power (1 or 2 W) did not significantly affect the cytotoxicity when the fluence was constant (20 J/cm2). However, an increase in fluence (10-40 J/cm2) led to a significant enhancement of cytotoxicity until maximal values were reached (30-40 J/cm2). A further increase in fluence (50 J/cm2) proved to induce a fall-off in cytotoxicity related to the intense photobleaching of HPD.
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PMID:MTT assays allow quick and reliable measurement of the response of human tumour cells to photodynamic therapy. 138 43

Four breast cancer cell lines covering a wide range of receptor characteristics were examined for their growth responses to oestradiol, insulin, EGF and the anti-oestrogen, tamoxifen. Stimulated cellular growth using both the MTT assay and 3H-thymidine incorporation into DNA, was measured against controls grown in a steroid reduced environment. The ER positive MCF-7 cell line showed clear growth responses to E2, insulin and EGF. This was also demonstrated, although to a lesser extent in the ZR-75-1 line which expresses lower levels of ER. In combination, these factors gave an additive growth response but the addition of EGF to maximal concentrations of insulin and oestradiol produced no further increase in growth. In contrast to these results, the two ER negative cell lines examined, MCF-7 Adr and MDA-MB-231 showed no growth response to exogenously applied steroids and in the case of MCF-7 Adr high concentrations of EGF were able to inhibit the growth of this cell line. They also showed high rates of growth in a steroid depleted environment which tends to suggest these cells are growing autonomously through autocrine growth factor induction.
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PMID:The response of breast cancer cells to steroid and peptide growth factors. 144 36

In the present study a slightly modified MTT assay was used in conjunction with cell counting to determine the antiproliferative efficacy of N-(2-chloroethyl)-N-nitroso-N'-2-hydroxyethylurea (HECNU), vinblastine, and hexadecylphosphocholine (HPC) in a panel of six tumor cell lines. This panel consisted of two human (MDA-MB231, MCF-7) and two rodents (1/C2, 1/C32) mammary-carcinoma cell lines as well as of two tumor cell lines of gastrointestinal origin (HT-29, KB). It was shown that the use of acid isopropanol as a solvent of the formazan crystals produced correlations between cell number and absorption that were as good as, if not better than, those seen after dimethylsulfoxide (DMSO) application. The optimal period of incubation with the MTT dye was 2 h. A comparison of the antiproliferative activity of HECNU revealed that the HT-29 cell line was most resistant [50% inhibition concentration (IC50), 138.7 mumol/l], followed by MCF-7 cells (IC50, 127.7 mumol/l), whereas MDA-MB231 cells showed the highest sensitivity (IC50, 6 mumol/l). Vinblastine induced the highest (MCF-7 cells; IC50, 0.68 nmol/l) and the lowest (1/C2 cells; IC50, 7.69 nmol/l) degrees of growth inhibition in cell lines derived from mammary carcinoma. This contrasted with the activity of HPC, which was considerably less effective in the four mammary-carcinoma cell lines (IC50 from 29.4 to 69.9 mumol/l) than in the two cell lines of gastrointestinal origin (IC50, 1.9 and 3.1 mumol/l). Interestingly, treatment with HPC stimulated the growth of 1/C32 cells in the lower dose range. After treatment with HECNU, the average IC50 value determined in the MTT assay was 2.4-fold that disclosed by cell counting, whereas the average values found for HPC and vinblastine by both methods corresponded fairly well, with the respective values obtained using the MTT assay being only 26% and 14% higher than those measured by cell counting. A dose-dependent increase in the mean size of MCF-7 cells was observed after exposure to HECNU, which--if taken into account--considerably reduced underestimation of this parameter by the MTT assay. No variation in cell size was noted following treatment with HPC and vinblastine. Thus, depending on the antitumor agent used, the MTT assay can result in slight or even considerable underestimation of the antitumor efficacy of certain compounds and may need correction by consideration of the effect of the drugs on cell size.
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PMID:Assessment of antineoplastic agents by MTT assay: partial underestimation of antiproliferative properties. 150 77

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

Interferons (IFNs) have been known to possess an antiproliferative effect on tumor cells besides their well characterized antiviral effect in cell cultures. The mechanism of action of the different IFNs is not fully understood, but in recent years a number of IFN-inducible genes, the presumed mediators of IFN action, have been identified. In the present study we examined the antiproliferative effect of IFN-alpha and IFN-gamma on human breast cancer cells (MCF-7) using (i) the MTT dye formation assay and (ii) anchorage-independent (AI) growth in soft agar. Both IFN-alpha and IFN-gamma were found to have an antiproliferative effect on the growth of MCF-7 cells. In addition, the kinetics of induction of a number of IFN-inducible genes was also examined. The expression of these genes was measured by mRNA analyses using specific [alpha-32P]-labeled cDNAs as probes. The induction of these genes by IFN-alpha and IFN-gamma is a primary effect of IFN, as de novo protein synthesis is not required for their induction. Our results on the kinetics of induction of these genes by IFN-alpha and IFN-gamma suggests a complex mechanism of ligand-dependent gene activation in this cell line with some similar and dissimilar pathways.
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PMID:Interferon-alpha and gamma mediated gene responses in a human breast carcinoma cell line. 171 85

The cytotoxic effect of a combination of interferons (type I and II) and tumor necrosis factor (TNF), with an antiestrogenic drug, tamoxifen (TAM), was investigated in the estrogen receptor positive human breast carcinoma cell line, MCF-7. Cytotoxicity was measured by the MTT assay. In an attempt to define the molecular basis for the interaction between the interferons (IFNs) and TNF or any one of the cytokines with TAM, the induction characteristics of a number of IFN-induced mRNAs in response to IFNs, TNF, and TAM were studied. We observed an augmentation of the cytotoxic effect of TNF when it was combined with TAM. There appears to be an overlap in signalling mechanisms of IFNs and TNF as two of the IFN-inducible genes, 1-8 and 6-16 are also induced by TNF. mRNA 1-8 was induced by both IFN-alpha (type I) and IFN-gamma (type II). We conclude that TNF potentiates the cytotoxic effects of TAM in MCF-7 cells and that the three cytokines IFN-alpha, IFN-gamma, and TNF share some pathways that lead to specific induction of some cytokine responsive genes.
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PMID:Augmentation of cytotoxicity using combinations of interferons (types I and II), tumor necrosis factor-alpha, and tamoxifen in MCF-7 cells. 176 97

We assessed the in vitro drug-induced cytotoxicity by means of the rapid low-cost but weakly sensitive Thiazolyl blue (MTT) test, and the less rapid, higher cost, but highly sensitive cell image analysis (CIA) test. We studied the influence of three drugs, i.e. a vinca-alkaloid (Navelbine), an alkylating investigational agent (PE1001), and an intercalating drug, i.e. adriamycin, on the proliferation (MTT test) and cell kinetics (CIA test) of the mouse MXT and the MCF-7 mammary cancer cell lines. Adriamycin and PE1001 decreased MXT and MCF-7 cell proliferation in a dose-dependent manner as assessed by both the MTT and CIA tests. Navelbine was highly cytotoxic in a dose-dependent manner. We demonstrated that Navelbine arrests cells in the M phase without altering the G2 phase. In sharp contrast, PE1001 arrest cells in the G2 phase without altering the M phase. An adriamycin-induced effect was apparent on S phase. Thus, the MTT test allows the screening of a great number of drugs analyzed at the cell proliferation level and, in the case of MTT positive drug-induced response, the CIA test enabled the drug-induced effect at cell cycle kinetic level to be investigated.
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PMID:The combination of the tetrazolium derivative reduction (MTT) and digital cell image analysis to monitor in vitro the cytotoxicity of anti-neoplastic drugs. 201 64

l-Carrageenan is a polysulphated carbohydrate that antagonises some heparin-binding growth factors. We assessed the effect of l-carrageenan on the proliferation of a panel of cell lines, some of which require heparin-binding growth factors for mitogenesis. The importance of growth factor antagonism for the anti-proliferative activity was also determined. Cell proliferation was determined by cell counts and a tetrazolium dye (MTT) assay, and DNA synthesis was determined by thymidine incorporation. The proliferation of the basic fibroblast growth factor (bFGF)-dependent endothelial cell line FBHE was inhibited by daily administration of l-carrageenan in a dose-dependent manner [concentration inhibiting cell growth by 50% (IC50 value), approx. 0.5 microgram/ml]. However, excess bFGF did not reverse the inhibitory effect. DNA synthesis was completely inhibited by concentrations of l-carrageenan that nonetheless allowed significant protein synthesis to occur. The proliferation of the androgen-dependent prostate-carcinoma cell line LNCaP was also inhibited by l-carrageenan (IC50 value, 5.5 micrograms/ml) and the cells were arrested at the G1/S boundary. l-Carrageenan inhibited DNA synthesis in MCF-7 cells stimulated by bFGF and transforming growth factor alpha (TGF alpha) but not in those stimulated by insulin-like growth factor 1 (IGF-1). Blocking IGF-1-mediated DNA synthesis with anti-IGF-1 receptor antibody alpha IR3 enhanced the inhibitory activity of l-carrageenan against MCF-7 cells grown in serum. A number of other transformed and non-transformed cell lines were either partially inhibited or not inhibited by l-carrageenan. l-Carrageenan had low anti-coagulant activity. l-Carrageenan is a selective anti-proliferative agent and warrants further investigation for anti-angiogenic therapy (in view of its activity against endothelial cells) and for the treatment of androgen-dependent prostate cancer.
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PMID:Selective inhibition of cell proliferation and DNA synthesis by the polysulphated carbohydrate l-carrageenan. 762 52

The growth interactions between human cancer cells and primary cultured human fibroblasts, and the effects of suramin on them, were investigated using a double-chamber technique combined with a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay. Human fibroblasts obtained from various organs resected surgically were cultured in a monolayer and used after the third or fourth passage. In the double-chamber assay, the growth of cancer cells in the top chamber was significantly stimulated by some types of fibroblasts in the bottom chamber in a fibroblast density-dependent manner. Interestingly, the growth of cancer cells was stimulated at 140%-147% by fibroblasts obtained from an organ where cancer cells had developed, the MCF-7 versus mammary fibroblasts, and in LS-180 versus colonic fibroblasts, but not by their fibroblast-conditioned medium. Suramin completely inhibited the growth-enhancing interaction between MCF-7 and mammary fibroblasts, and between SH-101 and lung fibroblasts at a clinical concentration of from 50 micrograms/ml to 300 micrograms/ml. It also reduced the growth of LS-180 co-cultured with colon-fibroblasts, but the inhibitory effect was incomplete. These results suggest that mutual growth reliance exists between human cancer cells and primary cultured fibroblasts by diffusible factors secreted by both cells, and that these enhancing effects are related in part to the growth and metastasis of cancer cells in vivo. Suramin was found to have an inhibitory effect on their interaction at a clinically achievable concentration in vitro.
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PMID:The inhibitory effect caused by suramin on the paracrine growth of human cancer cells and fibroblasts. 800 67

Two multidrug-resistant breast cancer cell lines (MCF-7/AdrVp and MCF-7/D.40) each expressing a different membrane protein, involved in the drug resistance, have been treated with a transferrin-doxorubicin conjugate. Conjugates have shown an increase of activity over free doxorubicin on these resistant cell lines. Growth inhibition of doxorubicin-resistant cells, as evaluated by the MTT-assay, was higher for conjugates than for free doxorubicin especially for a 4-day contact period. I D 50 were twice and 10-fold lower for the conjugate than for free doxorubicin on resistant cells. MCF-7/AdrVp seemed to be particularly affected by the conjugate even if its intracellular content of doxorubicin was similar. With the Trf-Dox conjugate, an inverted correlation does exist between the drug-DNA content and the cytotoxicity of the conjugate. Verapamil influenced the uptake of free doxorubicin but not the uptake of Trf-Dox conjugate, thus showing a different mechanism of entry.
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PMID:Sensitivity of multidrug-resistant MCF-7 cells to a transferrin-doxorubicin conjugate. 801 39


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