1. Medical Genomics Research Center, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran. 2. Department of Genetics, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran 3. Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abstract
Introduction
Dexamethasone is a type of corticosteroid medication. dexamethasone has anti-inflammatory effects that are produced via several mechanisms, including inhibition of phospholipase a2, prostaglandin h2 synthase or cyclooxygenase-2 expression. the anti-inflammatory and anti-proliferative properties of dexamethasone have made it part of conventional therapy for multiple myeloma. the aim of this study is to investigate the anti proliferative and cytotoxic effects of dexamethasone against colon cancer cell lines.
Methods
The human colorectal cancer cell line, ht-29 cultured in rpmi-1640 medium that supplemented with 10% fetal bovine serum. 80 x103 cells/well were seeded into 96-well plates and then treated with various concentrations of dexamethasone (from 0.1 to 1000 µm). then incubated for 24, 48 and 72 hours at 37°c with 5% co2. the cytotoxic effect was measured by mtt assay and the absorbance was read at 546nm in a spectrophotometer. the 50% inhibiting concentration (ic50) was determined graphically.
Results
Our results show that dexamethasone induced cell death in a dose and time-dependent manner. mtt assays showed that treatment with dexamethasone at 1000µm significantly inhibited the growth of treated ht-29 cells compared to the untreated cells (negative control). then the percentage of cell viability was calculated. ic50 for ht-29 cells was 1000µm after 48h incubation. results confirmed the anti-proliferative effect of dexamethasone on mentioned cell line.
Conclusion
Our results may suggest that the gene expression which is contributed in cell proliferation and apoptosis has been changed under pressure of dexamethasone.
