Effects of diethyldithiocarbamate on proliferation, redifferention, and apoptosis in human hepatoma cells
Abstract
Aim: To examine the effects of diethyldithiocarbamate (DDC) on the proliferation, redifferentiation, and apoptosis in human hepatoma cells.
Methods: Cell surface charge, biochemical changes, cell growth in soft agar, single cell electrophoresis, electron microscopy examination, and flow cytometry analysis were measured.
Results: After being treated with DDC 3 mmol/L the growth curve and mitotic index of human hepatoma cells decreased remarkably, and the cellular growth inhibitory rate amounted to 52.4 %. The indices related with cell malignancy were alleviated significantly, such as the cell surface charge decreased significantly, the electrophoresis rate dropped from 1.6 to 0.8 micron . s-1 . V-1 . cm-1, the average value of alpha-fetoprotein (alpha-FP) content decrease d from 314 to 95 microg/g (protein), and gamma-glutamyl-transpeptidase (gamma-GT) activity from 0.9 to 0.14 U/g (protein). The cell differentiation index increased significantly, such as the average levels of tyrosine-alpha-ketoglutarate transaminase (TAT) activity increased from 11.6 to 36 micromol/g (protein), and the colonogenic potential decreased by 95.6 %. The apoptotic bodies, detached cells, and apoptotic morphological features appeared, and the treated cells DNA was fragmented as observed by the comet assay. The flow cytometric results showed that a 42.9 % fractional DNA content existed in the treated cells.
Conclusion: DDC can inhibit human hepatoma cells proliferation, and can induce redifferentiation as well as apoptosis.
Keywords:
Methods: Cell surface charge, biochemical changes, cell growth in soft agar, single cell electrophoresis, electron microscopy examination, and flow cytometry analysis were measured.
Results: After being treated with DDC 3 mmol/L the growth curve and mitotic index of human hepatoma cells decreased remarkably, and the cellular growth inhibitory rate amounted to 52.4 %. The indices related with cell malignancy were alleviated significantly, such as the cell surface charge decreased significantly, the electrophoresis rate dropped from 1.6 to 0.8 micron . s-1 . V-1 . cm-1, the average value of alpha-fetoprotein (alpha-FP) content decrease d from 314 to 95 microg/g (protein), and gamma-glutamyl-transpeptidase (gamma-GT) activity from 0.9 to 0.14 U/g (protein). The cell differentiation index increased significantly, such as the average levels of tyrosine-alpha-ketoglutarate transaminase (TAT) activity increased from 11.6 to 36 micromol/g (protein), and the colonogenic potential decreased by 95.6 %. The apoptotic bodies, detached cells, and apoptotic morphological features appeared, and the treated cells DNA was fragmented as observed by the comet assay. The flow cytometric results showed that a 42.9 % fractional DNA content existed in the treated cells.
Conclusion: DDC can inhibit human hepatoma cells proliferation, and can induce redifferentiation as well as apoptosis.