ABSTRACT
The aim of the present study was to determine the effect of the combination of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and adriamycin (ADM) on the human breast cancer cell line MCF-7 and to identify potential mechanisms of apoptosis. Cell viability was analyzed by the MTT assay and the synergistic effect was assessed by the Webb coefficient. Apoptosis was quantified using the annexin V-FITC and propidium iodide staining flow cytometry. The mRNA expression of TRAIL receptors was measured by RT-PCR. Changes in the quantities of Bax and caspase-9 proteins were determined by Western blot. MCF-7 cells were relatively resistant to TRAIL (IC50 >10 µg/mL), while MCF-7 cells were sensitive to ADM (IC50 <10 µg/mL). A subtoxic concentration of ADM (0.5 µg/mL) combined with 0.1, 1, or 10 µg/mL TRAIL had a synergistic cytotoxic effect on MCF-7 cells, which was more marked with the combination of TRAIL (0.1 µg/mL) and ADM (0.5 µg/mL). In addition, the combined treatment with TRAIL and ADM significantly increased cell apoptosis from 9.8 percent (TRAIL) or 17 percent (ADM) to 38.7 percent, resulting in a synergistic apoptotic effect, which is proposed to be mediated by up-regulation of DR4 and DR5 mRNA expression and increased expression of Bax and caspase-9 proteins. These results suggest that the combination of TRAIL and ADM might be a promising therapy for breast cancer.
Subject(s)
Humans , Antibiotics, Antineoplastic/pharmacology , Apoptosis/drug effects , Breast Neoplasms/pathology , Doxorubicin/pharmacology , TNF-Related Apoptosis-Inducing Ligand/pharmacology , Blotting, Western , Cell Line, Tumor , Caspase 9/analysis , Drug Synergism , Flow Cytometry , Reverse Transcriptase Polymerase Chain Reaction , RNA, Messenger/analysis , /analysisABSTRACT
Treatment of heart failure should include correction of the underlying cause. These causes include large left to right shunts, obstructive lesions, arrhythmias, primary myocardial disease etc. The main pharmacological therapy includes inotropic agents, vasodilators and diuretics. Inotropic agents increase myocardial contractility and include digoxin, intravenous dopamine, dobutamine and isoproterenol. Vasodilators improve cardiac pump performance by decreasing the vascular resistance and/or increasing the venous capacitance. Commonly used vasodilator agents include angiotensin converting enzyme inhibitors (captopril, enalapril etc.), hydralazine, prazosin hydrochloride etc. Diuretics inhibit salt and water reabsorption promoting their excretion. Furosemide, thiazide diuretics, aldactone, are commonly used diuretics. Electrolyte and acid-base imbalance can occur on chronic diuretic therapy. Cardiac transplantation is considered for patients where all medical management has failed.