formazans and Leukemia

The MTT-based assay relies upon the cellular reduction of tetrazolium salts to their intensely colored formazans. The test is easy to perform in hematological malignancies and is adaptable for high throughput of samples, although there are some minor limitations in its application resulting from metabolic interference. This class of assays are highly accurate for predicting drug resistance, whereas their predictive value for drug sensitivity depends on the type of disease and drug or drug combination used. They have been found to predict clinical response to fludarabine FLD in B-CLL and were useful for predetermining clinical potential of a single drug or drug combination in AML patients. Extensive studies with ALL patients have supported their advantage for selecting effective drug treatment of the disease. To conclude, pretreatment chemosensitivity assays may help in the selection of chemotherapeutic drugs with the greatest likelihood for clinical effectiveness, and in the exclusion of uneffective therapy. This can lead to improved disease management, response, survival and use of financial resources.

Topics: Antineoplastic Agents; Cell Division; Cell Survival; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Formazans; Humans; Leukemia; Predictive Value of Tests; Tetrazolium Salts

Topics: Cell Adhesion; Cell Differentiation; Cell Line; Chemotaxis, Leukocyte; Dimethylformamide; Formazans; Humans; Leukemia; Lymphokines; N-Formylmethionine Leucyl-Phenylalanine; Nitroblue Tetrazolium; Oxidation-Reduction; Receptors, Formyl Peptide; Receptors, Immunologic; Tetradecanoylphorbol Acetate; Tretinoin

A novel approach to circumvent multidrug resistance is hybridization of natural products in dimers. We analyzed homodimers of two artesunic acid molecules and heterohybrids of artesunic acid and betulin in human CCRF-CEM and multidrug-resistant P-glycoprotein-overexpressing CEM/ADR5000 leukemia cells. Multidrug-resistant cells were not cross-resistant to the novel compounds. Collateral sensitivity was observed for artesunic acid homodimer. Artesunic acid and artesunic acid homodimer induced G0/G1 cell cycle arrest, apoptosis, and formation of reactive oxygen species.

Topics: Apoptosis; Artemisinins; Cell Cycle; Cell Line, Tumor; Cell Survival; Drug Resistance, Neoplasm; Flow Cytometry; Formazans; Humans; Leukemia; Magnetic Resonance Spectroscopy; Reactive Oxygen Species; Spectrometry, Mass, Electrospray Ionization; Succinates; Triterpenes

4-(4-Bromophenyl)-2,3-dihydro-N,3-bis(3,4,5-trimethoxyphenyl)-2-oxoidmi-dazole-1-carboxamide (MZ3) is one of the synthesized combretastatin-A-4 analogues and has been reported that it displayed a promising specific activity against leukemia cell lines. Our purpose was to investigate the mechanism of MZ3's cytotoxicity.. Cytotoxicity was measured by MTT method, apoptosis was measured by flow cytometry. DNA fragmentation was tested by agarose gel electrophoresis. Mitochondrial membrane potential (DeltaPsim) was detected by JC1 staining and flow cytometry, while intracellular reactive oxygen species (ROS) was detected by 5-(and-6)-carboxy-2'-7'-dichlorofluorescin diacetate staining and flow cytometry. Protein expression was analyzed by western blotting. In vivo activity of MZ3 was assayed through severe combined immunodeficiency (SCID) mice model of human leukemia engrafts.. MZ3 exhibited high anti-cancer activity in six leukemia cell lines, including two drug-resistant cell lines. MZ3 induced DNA fragmentation, and caused an elevation of ROS and a loss of DeltaPsim in HL60 cells. MZ3 also induced the activation of caspase-3, influenced the expression of Bcl-2 family members, MAPKs and other proteins relative to mitochondria-induced apoptosis. In addition, N-acetylcysteine cannot inhibit HL60 cell apoptosis caused by MZ3. Furthermore, a prolonged survival time was observed after treatment with MZ3 in SCID mice model of human leukemia engrafts.. MZ3 is a potent compound against leukemia cell lines both in vitro and in vivo, and the mitochondrial pathway mediated by Bcl-2 protein family and MAPKs might be involved in signaling MZ3-induced apoptosis.

Topics: Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Survival; DNA Fragmentation; DNA, Neoplasm; Drug Screening Assays, Antitumor; Formazans; HL-60 Cells; Humans; Imidazoles; K562 Cells; Leukemia; Longevity; Membrane Potential, Mitochondrial; Mice; Mice, SCID; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Stilbenes; Tetrazolium Salts

Cytosine arabinoside (1-beta-D-arabinofuranosylcytosine; Ara-C) is the most important antimetabolite used to induce remission in acute leukemia, but cellular resistance to Ara-C reflects a poor prognosis in cancer chemotherapy. To further investigate the mechanisms of resistance to Ara-C, we have established Ara-C-resistant NALM-6 cells. The activation of nuclear factor kappaB (NF-kappaB) was accompanied by the acquisition of Ara-C resistance. Telomerase activity has also increased with the acquisition of Ara-C resistance. The expression of Bid, Bax, or p53 proteins have been shown to increase correlated with the acquisition of Ara-C resistance. In contrast to the increase in these proteins, Bcl-2, Bcl-x, and Bag-1 proteins remained unchanged with the acquisition of Ara-C resistance. Fas expression increased with the acquisition of Ara-C resistance in the late stage. The induction of apoptosis and reduction of cell viability by cytotoxic anti-Fas antibody was more susceptible in resistant cells than parental cells. In conclusion, this report has shown that resistance to Ara-C up-regulates the activation of NF-kappaB, telomerase activity and Fas expression.

Topics: Antimetabolites, Antineoplastic; Apoptosis; bcl-2-Associated X Protein; BH3 Interacting Domain Death Agonist Protein; Cell Line, Tumor; Cytarabine; Drug Resistance, Neoplasm; fas Receptor; Formazans; Humans; Leukemia; NF-kappa B; Telomerase; Tetrazolium Salts; Tumor Suppressor Protein p53; Up-Regulation

PMA (10, 20 ng/ml) and doxorubicin (5-20 ng/ml) decreased the viability and MTT-activity of NALM-1 pre-B leukemic cells (3 days' treatment). Further, CD10 was downregulated, suggesting that PMA and doxorubicin induced differentiation of NALM-1 cells. However, PMA did not alter expression of B cell markers CD20 and of mIgM. In contrast to PMA, another differentiation agent ATRA did not alter CD10 expression on NALM-1 cells but affected viability after 6 days (5, 10 ng/ml). The data in this study are the first evidence that PMA and doxorubicin inhibited viability and MTT activity and induced partial differentiation, by decreasing CD10 on NALM-1 cells.

Topics: Antibiotics, Antineoplastic; Antigens, CD20; Biomarkers, Tumor; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Doxorubicin; Enzyme-Linked Immunosorbent Assay; Formazans; Humans; Immunoglobulin mu-Chains; Leukemia; Neprilysin; Syndecan-1; Tetradecanoylphorbol Acetate; Tetrazolium Salts; Time Factors; Tretinoin

Plantago major linn. and P. asiatica Linn. (Plantaginaceae) are commonly used as folk medicine in Taiwan for treating infectious diseases related to the respiratory, urinary and digestive tracts. In this study, we investigated the antiviral, cytotoxic and immunomodulatory activities of hot water extracts of these two species in vitro on a series of viruses, namely herpesviruses (HSV-1 and HSV-2), adenoviruses (ADV-3, ADV-8 and ADV-11), and on various human leukemia, lymphoma and carcinoma cells with XTT, BrdU and IFN-gamma kits. Results showed that hot water extract of P. asiatica possessed significant inhibitory activity on the proliferation of lymphoma (U937) and carcinoma (bladder, bone, cervix, kidney, lung and stomach) cells and on viral infection (HSV-2 and ADV-11). P. major and P. asiatica both exhibited dual effects of immunodulatory activity, enhancing lymphocyte proliferation and secretion of interferon-gamma at low concentrations (< 50 microg/ml), but inhibiting this effect at high concentration (> 50 microg/ml). The present study concludes that hot water extracts of P. major and P. asiatica possess abroad-spectrum of antileukemia, anticarcinoma and antiviral activities, as well as activities which modulate cell-mediated immunity. Further investigations to elucidate the active component(s) of P. asiatica and P. major and to evaluate their clinical application are warranted.

Topics: Adenoviridae; Adjuvants, Immunologic; Antineoplastic Agents, Phytogenic; Antiviral Agents; Drug Screening Assays, Antitumor; Enzyme-Linked Immunosorbent Assay; Formazans; Herpesvirus 1, Human; Humans; Interferon-gamma; Leukemia; Lymphocyte Activation; Plant Extracts; Plantago; Tumor Cells, Cultured

In order to establish a new more rapid, safe and sensitive colorimetric assay for the proliferation of leukemic cells, MTS/pms has been developed. This automated colorimetric assay is based on the characteristic of viable and metabolically active leukemic cells to cleave MTS/pms into a water-soluble product whose optical density is determined at 492 nm by an automated microtiter-plate reader photometer. The results indicated that only active leukemic cells cleaved MTS/pms into product measured, and dead cells did not reduce MTS/pms. A linear relations hip were found between the viable cell number and optical density of MTS/pms cleaved by HL-60 and K562 cell (r = 0.963). Compared with MTT and INT assays, the reduced product of MTS/pms is water-soluble. It is concluded that MTS/pms colorimetric assay is more rapid, accurate and sensitive for the bioassay of proliferation of leukemic cells.

Topics: Cell Division; Colorimetry; Formazans; HL-60 Cells; Humans; K562 Cells; Leukemia; Methylphenazonium Methosulfate; Tetrazolium Salts; Thiazoles