mtt-formazan and Adenocarcinoma

Two new coumarins, 1 and 2, along with four known coumarins (3-6) have been isolated from Corydalis heterocarpa. On the basis of spectroscopic and chemical methods, compounds 1 and 2 were elucidated as (2'S,7'S)-O-2-methylbutanoyl-columbianetin and (2'S)-columbianetin-3'-sulfate, respectively. The anti-proliferative activity against human cancer cells of compounds 1-6 isolated from C. heterocarpa was evaluated using a MTT assay and by mRNA expression of several factors related to apoptosis. Among them, compound 2 exerted the more potent anti-proliferative activity compared with the other compounds treated. The potent inhibitory effect of compound 2 was produced by induction of apoptosis through activating Bax, p53 and p21 expressions.

Topics: Adenocarcinoma; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Survival; Corydalis; Coumarins; Drug Screening Assays, Antitumor; Female; Formazans; Humans; Neoplasms; Plant Extracts; Tetrazolium Salts

Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) is an uncoupler of mitochondrial oxidative phosphorylation in eukaryotic cells. Here, we evaluated the in vitro effects of FCCP on the growth of Calu-6 lung cancer cells. FCCP inhibited the growth of Calu-6 cells with an IC(50) of approximately 6.64+/-1.84 microM at 72 h, as shown by MTT. DNA flow cytometric analysis indicated that FCCP induced G1 phase arrest below 20 microM of FCCP. Treatment with FCCP decreased the level of CDKs and cyclines in relation to G1 phase. In addition, FCCP not only increased the p27 level but also enhanced its binding with CDK4, which was associated with hypophosphorylation of Rb protein. While transfection of p27 siRNA inhibited G1 phase arrest in FCCP-treated cells, it did not enhance Rb phosphorylation. FCCP also efficiently induced apoptosis. The apoptotic process was accompanied with an increase in sub-G1 cells, annexin V staining cells, mitochondria membrane potential (MMP) loss and cleavage of PARP protein. All of the caspase inhibitors (caspase-3, -8, -9 and pan-caspase inhibitor) markedly rescued the Calu-6 cells from FCCP-induced cell death. However, knock down of p27 protein intensified FCCP-induced cell death. Moreover, FCCP induced the depletion of GSH content in Calu-6 cells, which was prevented by all of the caspase inhibitors. In summary, our results demonstrated that FCCP inhibits the growth of Calu-6 cells in vitro. The growth inhibitory effect of FCCP might be mediated by cell cycle arrest and apoptosis via decrease of CDKs and caspase activation, respectively. These findings now provide a better elucidation of the mechanisms involved in FCCP-induced growth inhibition in lung cancer.

Topics: Adenocarcinoma; Annexin A5; Antineoplastic Agents; Apoptosis; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; Cell Cycle; Cell Line, Tumor; Cell Survival; Cyclin-Dependent Kinases; DNA, Neoplasm; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Formazans; G1 Phase; Humans; Inhibitory Concentration 50; Lung Neoplasms; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Membranes; Tetrazolium Salts; Time Factors; Uncoupling Agents

Arsenic trioxide (As2O3) shows a significant therapeutic effect upon acute promyelocytic leukemia (APL) and can induce the apoptosis of NB4 cells, which attracts scholars' great attention. Especially, the therapeutic effect on solid carcinoma has been paid more close attention to. The present study is to evaluate the effect of As2O3 on human colorectal carcinoma cells (LS-174T cell) and the activity of telomerase in vitro and in vivo. This research made use of the electron microscope, polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), fluorescence-activated cell sorter (FACS), MTT in vitro and in vivo (LS-174T xenograft model of nude mice). With the increasing concentration of As2O3, the ratio of living cells to dead cells decreased significantly, and the IC50 value was 5.23micromol/L; cells of the experimental groups endured a series of morphological changes similar to the features of apoptosis. Apoptosis curve of FACS pictures appeared after 24h, and the cells showed apoptosis in a time-dependent manner; As2O3 can inhibit the activity of telomerase of the cell extraction, obviously, in a concentration-dependent and time-dependent manner after 24h. As to the inhibition impact of As2O3 on the xenograft model of nude mice in the two indexes, tumor volume and weight, there was a significant difference between As2O3 and the control group; there was no difference between As2O3 and the fluorouracil (5-FU) group; in the group of peritoneal injections of As2O3, the cancer cells connected loosely with each other, nucleus changed markedly, and heterochromatin concentrated under the nucleus membrane. From the in vitro and in vivo experiment, we can see that As2O3 inhibited LS-174T cell growth mainly by inducing cell apoptosis, partly by the inhibition of telomerase activity.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Apoptosis; Arsenic Trioxide; Arsenicals; Cell Line, Tumor; Cell Nucleus; Cell Survival; Colorectal Neoplasms; Cytoplasmic Structures; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Formazans; Humans; Mice; Mice, Nude; Oxides; Polymerase Chain Reaction; Telomerase; Tetrazolium Salts; Xenograft Model Antitumor Assays

Ca2+ and Mg2+ have a fundamental role in many cellular processes and ion channels are involved in normal physiologic processes and in the pathology of various diseases. The aim here was to show that the presence and potential role of transient receptor potential melastatin 7 (TRPM7) channels in the growth and survival of AGS cells, the most common human gastric adenocarcinoma cell line. The patch-clamp technique for whole-cell recording was used in AGS cells. TRPM7-specific small interfering RNAs were used for specific inhibition of TRPM7. Whole-cell voltage-clamp recordings revealed the TRPM7-like currents that activated spontaneously following loss of intracellular Mg2+. The current had a non-linear current-voltage relationship with the characteristic steep outward rectification associated with TRPM7 channels. Reverse transcription-polymerase chain reaction, western blotting, and immunoreactivity all showed abundant expression of TRPM7 messenger RNA and protein in AGS cells. Transfection of AGS cells with TRPM7 siRNA significantly reduced the expression of TRPM7 mRNA and protein as well as the amplitude of the TRPM7-like currents. Furthermore, we found that Mg2+ is critical for the growth and survival in AGS cells. Blockade of TRPM7 channels by La3+ and 2-APB or suppression of TRPM7 expression by siRNA inhibited the growth and survival of these cells. Human gastric adenocarcinoma cells express TRPM7 channel whose presence is essential for cell survival. The protein is a likely potential target for the pharmacological treatment of gastric cancer.

Topics: Adenocarcinoma; Caspase 3; Cell Death; Cell Line, Tumor; Electrophysiology; Formazans; Humans; Immunohistochemistry; Patch-Clamp Techniques; Protein Serine-Threonine Kinases; RNA Interference; RNA, Messenger; RNA, Small Interfering; Stomach Neoplasms; Tetrazolium Salts; TRPM Cation Channels; Zinc Fingers

The effects of the alpha-diketone derivatives 2,3- and 3,4-hexanediones were investigated in three non-neuronal cell lines (MCF7, HepG(2) and CaCo-2) as well as in the neuroblastoma line, SH-SY5Y. The MTT reduction assay was employed to determine the necrotic effects of the alpha-diketones and the neurotoxin 2,5-hexanedione over 4, 24 and 48 hr exposures. Flow cytometry was also used to study the effects of the three isomers on the cell cycle of the SH-SY5Y line only. With 2,5-hexanedione, the mean MTT IC(50) decreased more than 10-fold from 4 to 48 hr. The toxicities of both alpha-diketones were similar, with a more than 18-fold increase in sensitivity of the SH-SY5Y at 24 hr compared to that of 4 hr. With flow cytometry at 48 hr, SH-SY5Y apoptosis with 2,5-hexanedione rose throughout the concentration range evaluated (0-30 mM) while 2,3- and 3,4-hexanediones showed apoptosis over the concentration range 1-1.6 mM, with 3,4-hexanedione being the more potent compared to the 2,3-isomer. At 1.6 mM nearly all the cells had entered apoptosis in the presence of the 3,4-isomer, (94.9 +/- 1.4%) but only 57.5 +/- 4.1% of the 2,3-isomer-treated cells had reached that stage. The 2,3- and 3,4-isomers in diets alone may not pose a serious threat to human health. Further studies may be necessary to evaluate the effects of other dietary components on their toxicity. These alpha-diketones also display a degree of toxic selectivity towards neuroblastoma cells, which may have therapeutic implications.

Topics: Adenocarcinoma; Apoptosis; Breast Neoplasms; Carcinoma, Hepatocellular; Cell Line, Tumor; Cell Survival; Colonic Neoplasms; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Flow Cytometry; Formazans; Hexanones; Humans; Isomerism; Neuroblastoma; Neurons; Tetrazolium Salts

4-Methyl-2,7-diamino-5,10-diphenyl-4,9-diazapyrenium hydrogensulfate (ADAP) is a potential antitumor compound because of its DNA and RNA intercalating ability. In this study, cellular uptake, intracellular distribution as well as mechanism of action, antitumor activity in vitro and toxicity in vivo of ADAP were investigated.. Based on the fluorescence properties of ADAP, its entry and distribution into live cells were analyzed by fluorescence microscopy. The in vitro antiproliferative activity was determined using MTT test. For screening of topoisomerase II-targeted effects of ADAP, the cell-free assay and immunoband depletion assay were used. Expression of the genes c-mos, c-N-ras, c-Ki-ras, c-H-ras, p53 and caspase 3 in Caco-2 cells treated with ADAP was examined by RT-PCR. Toxicity in vivo was determined using C3HHf/Bu Zgr/Hr mice treated by single or multiple doses of ADAP at a concentration of 25 mg/kg.. ADAP in microM concentrations entered into MIAPaCa-2 cell's cytoplasm in 5 min and into nuclei in 60 min after administration. Intracellular distribution of ADAP depended on the period of treatment time. ADAP (0.1-100 microM) strongly inhibited the growth of both mouse (FsaR, SCCVII) and human tumor cells (HeLa, Caco-2, HT-29, MIAPaCa-2, HBL, HEp-2, SW620, MCF-7) compared to its weak cytotoxicity on controls and normal cells (WI38). Results of both topoisomerase II assays showed that ADAP is not a topoisomerase II poison. Expression of investigated genes was dependent on the incubation time, except for p53 and c-H-ras. Morphological changes in tissues and organs of mice were not observed. Results of patohistological analysis have been confirmed by hematological and clinical-chemical analysis of blood of treated and non-treated animals.. ADAP is a strongly bioactive compound with antitumor potential in vitro. The antitumor potential in vivo remains to be identified.

Topics: Adenocarcinoma; Aminoquinolines; Animals; Antineoplastic Agents; Caco-2 Cells; Cell Line, Tumor; Cell Survival; Colonic Neoplasms; DNA Topoisomerases, Type II; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Formazans; Gene Expression; Humans; Intercalating Agents; Male; Mice; Mice, Inbred C3H; Quinolinium Compounds; RNA, Messenger; Tetrazolium Salts

Recently, we have introduced [tris(1,10-phenanthroline)lanthanum(III)] trithiocyanate (KP772, FFC24) as a new lanthanum compound which has promising anticancer properties in vivo and in vitro. Aim of this study was to investigate the impact of ABC transporter-mediated multidrug resistance (MDR) on the anticancer activity of KP772. Here, we demonstrate that all MDR cell models investigated, overexpressing ABCB1 (P-glycoprotein), ABCC1 (multidrug resistance protein 1), or ABCG2 (breast cancer resistance protein) either due to drug selection or gene transfection, were significantly hypersensitive against KP772. Using ABCB1-overexpressing KBC-1 cells as MDR model, KP772 hypersensitivity was demonstrated to be based on stronger apoptosis induction and/or cell cycle arrest at unaltered cellular drug accumulation. KP772 did neither stimulate ABCB1 ATPase activity nor alter rhodamine 123 accumulation arguing against a direct interaction with ABCB1. Accordingly, several drug resistance modulators did not sensitize but rather protect MDR cells against KP772-induced cytotoxicity. Moreover, long-term KP772 treatment of KBC-1 cells at subtoxic concentrations led within 20 passages to a complete loss of drug resistance based on blocked MDR1 gene expression. When exposing parental KB-3-1 cells to subtoxic, stepwise increasing KP772 concentrations, we observed, in contrast to several other metallo-drugs, no acquisition of KP772 resistance. Summarizing, our data demonstrate that KP772 is hyperactive in MDR cells and might have chemosensitizing properties by blocking ABCB1 expression. Together with the disability of tumor cells to acquire KP772 resistance, our data suggest that KP772 should be especially active against notoriously drug-resistant tumor types and as second line treatment after standard chemotherapy failure.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Breast Neoplasms; Carcinoma, Small Cell; Cell Cycle; Cell Line, Tumor; Dose-Response Relationship, Drug; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Formazans; HL-60 Cells; Humans; Lanthanum; Lung Neoplasms; Molecular Structure; Neoplasm Proteins; Organic Anion Transporters; Organometallic Compounds; Phenanthrolines; Sensitivity and Specificity; Tetrazolium Salts

Using three cytotoxicity assays, we have investigated the effect of the spermine analogue N1,N11-diethylnorspermine (DENSPM) on four human breast cancer cell lines with different known genetic lesions. Cells were seeded in 96 well plates and DENSPM was added 24 h later to give final concentrations from 0.1 to 100 microM. At 24, 48 and 72 h of treatment, the protein content was determined with a modified Lowry assay. Mitochondrial activity was determined with the AlamarBlue and MTT assays. These two assays differ with respect to where in the electron transport chain the reduction of the substrate takes place. Treatment with increasing concentrations of DENSPM resulted in differential responses in the four cell lines. There was a good of agreement between the protein content and the MTT assay showing increased negative effect with increased dose of DENSPM. The AlamarBlue assay on the other hand showed a stimulation of substrate reduction compared to control at DENSPM concentrations that were inhibitory according to the protein content and MTT assay. Thus, the data clearly show that the MTT and AlamarBlue assays are not equivalent. Importantly, the AlamarBlue assay presumably also reflects cytoplasmic reduction of the substrate through DENSPM-induced mechanisms.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Formazans; Humans; Spermine; Tetrazolium Salts

GnRH analogs have antiproliferative and/or apoptotic effects on prostate cancer cells. Also, neurotrophin receptors TrkA and p75 have been reported in normal prostate suggesting a role in the gland growth control. In prostate cancer, TrkA receptors seem to be overexpressed and p75 receptors show a decreased expression. These changes in neurotrophin receptors may be related with unbalanced growth in malignant cells. In the present study we investigate the effects of GnRH analogs (leuprolide and cetrorelix) on the expression of TrkA and p75 neurotrophin receptors in primary cultures of human prostate cancer cells.. Tissue was obtained from radical prostatectomies due to prostate adenocarcinoma. Cells were isolated after sequential enzyme digestion and cultured in defined media. Nerve growth factor (NGF) receptors in untreated cultures were estimated by immunofluorescence. Cultures were treated with leuprolide (agonist) or cetrorelix (antagonist) and expression of TrkA and p75 receptors were evaluated by semi quantitative RT-PCR (polymerase chain reaction) and western blot. Cell proliferation was estimated by MTT method and apoptosis through COMET assay.. Both leuprolide and cetrorelix induced a significant increase in p75 receptor gene and protein expression at a concentration that induce apoptosis and decrease proliferation. TrkA receptors showed no changes in presence of GnRH analogs.. GnRH analogs, leuprolide, and cetrorelix, change the ratio between neurotrophin receptors TrkA and p75 by increasing gene and protein expression of p75 receptor. Considering that TrkA receptor is related with proliferation and p75 with apoptosis, we suggest that our findings may explain, in part, the effect of GnRH analogs on prostate cancer growth.

Topics: Adenocarcinoma; Antineoplastic Agents, Hormonal; Apoptosis; Blotting, Western; Cell Proliferation; Comet Assay; Epithelial Cells; Formazans; Gonadotropin-Releasing Hormone; Humans; Leuprolide; Male; Prostatic Neoplasms; Receptor, Nerve Growth Factor; Receptor, trkA; Receptors, Nerve Growth Factor; Reverse Transcriptase Polymerase Chain Reaction; Tetrazolium Salts

Coumarin and its derivative 7-hydroxycoumarin (7-OHC) have antitumor and antimetastatic properties. The purpose of this study was to investigate the possible effects of these compounds on expression of the bcl-2 and Bax oncoproteins in two human lung cancer cell lines, A427 and Calu-1. The cells were cultured in vitro for 24 h in RPMI 1640 with 1.5% (v/v) ethanol, 1.0 mM ethanolic coumarin or 1.0 mM ethanolic 7-OHC. Viability was determined in each cell line by an MTT assay. Total protein was extracted from cell lysates and the bcl-2 and Bax oncoproteins were identified. Western blotting showed a decrease in bcl-2 and an increase in Bax in A427 cells cultured with coumarin or 7-OHC. Neither drug changed bcl-2 expression in Calu-1 cells compared to solvent controls, and Bax expression was only slightly increased by coumarin. We conclude that 7-OHC is a more potent inhibitor of cell proliferation than coumarin and has more marked effects on oncoprotein expression. Also, the A427 cell line was more sensitive to the drugs than Calu-1.

Topics: Adenocarcinoma; Antineoplastic Agents; bcl-2-Associated X Protein; Blotting, Western; Carcinoma, Squamous Cell; Cell Proliferation; Coumarins; Formazans; Humans; In Vitro Techniques; Lung Neoplasms; Proto-Oncogene Proteins c-bcl-2; Tetrazolium Salts; Tumor Cells, Cultured; Umbelliferones

Retinoids are natural differentiation-inducing compounds that are promising as anticancer agents. Cancer cell lines are valuable in the investigation of the potential of retinoids for the treatment of specific cancers. However, using different treatment conditions but the same cell lines, investigators have produced markedly contradictory results for the effectiveness of retinoids. The present study examined different factors in the treatment conditions that may have masked or interfered with the effects of retinoids and, thereby, resulted in this conflict. Our studies revealed that the effects of retinoids on cancer cell proliferation were influenced by serum, the choice of vehicle (DMSO vs ethanol) and its concentration, phenol red, the degree of cellular confluence, and the method of assessing proliferation (cell number or [3H]thymidine uptake vs the MTT assay). Optimized conditions were the use of serum-free, ethanol-free, and phenol red-free media, investigating cells in the log phase of growth, using

Topics: Adenocarcinoma; Antineoplastic Agents; Carbonic Anhydrases; Cell Count; Cell Differentiation; Cell Division; Culture Media, Serum-Free; Dimethyl Sulfoxide; DNA; Dose-Response Relationship, Drug; Ethanol; Fixatives; Formazans; Freezing; Humans; Light; Pancreatic Neoplasms; Phenolsulfonphthalein; Retinoids; Solvents; Tetrazolium Salts; Tumor Cells, Cultured

Human non-small cell lung cancer (N-SCLC), a common malignancy generally unmanageable by conventional cytotoxic chemotherapy, represents a major world health burden. Suramin, a polyanionic drug which appears to interfere with growth-factor/receptor interaction, has recently been shown to be cytostatic for small cell lung cancer cells; it may also be effective for N-SCLC. As insulin-like growth factor I (IGF-I) is a known progression agent for N-SCLC, we have examined the effects of suramin on the 'IGF-I system' in a panel of human N-SCLC cell lines. Colorimetric and thymidine incorporation assays were used to assess cell chemosensitivity whereas a radio-receptor assay was employed to evaluate IGF-I/receptor binding. Suramin reversibly reduced, in a concentration- and time-dependent manner, the growth of each N-SCLC cell line examined either cultured in serum-containing or serum-free medium. Furthermore, suramin caused a concentration-related inhibition of labeled IGF-I peptide specific binding on all cell lines studied. Suramin caused a significant reduction in the Bmax values with only weak variations in the affinity constants (Kd). We hypothesize that suramin interference with IGF-I mitogenic activity is a pathway by which this drug produces its effect in vitro. These data indicate further studies on the mechanism of action and pharmacology of suramin in vivo are warranted.

Topics: Adenocarcinoma; Binding, Competitive; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Division; DNA; Dose-Response Relationship, Drug; Formazans; Humans; Insulin-Like Growth Factor I; Lung Neoplasms; Mitogens; Radioligand Assay; Suramin; Tetrazolium Salts; Thymidine; Tumor Cells, Cultured