Effects of atropine on megakaryocytic differentiated K562 leukemia cells

Objective: Non-neuronal cholinergic system signaling pathways play a significant role in various malignancies, including leukemia, lung, colon, brain, and breast cancer. This study aims to investigate the effect of atropine on megakaryocytic differentiated cells, as well as to identify the apoptosis mechanisms. We also studied the effect of cholinergic drugs on muscarinic receptors and caspase gene expressions, cell proliferation and caspase activities in differentiated cells. Materials and Methods: K562 cells were induced into megakaryocytic differentiation using phorbol 12-myristate 13-acetate (PMA). The effects of agonists/antagonists on differentiated K562 cells were examined using cell viability and 5-Bromo-2-deoxy-uridine (BrdU) assays. Caspase activities were detected by the caspase assay kit. Protein expression levels were detected by western blotting. Results: Atropine reversed the effects of carbachol (CCh) on increased megakaryocytic differentiated leukemia cell survival and proliferation. The protein expression of M1 and M4 muscarinic receptors was upregulated by CCh, an effect that was reversed by atropine. CCh alone did not significantly change levels of M2, M3, and M5 muscarinic receptor proteins in megakaryocytic differentiated K562 leukemia cells. Conclusion: M2, M3 muscarinic receptors and caspase 9 may have important functions in preventing the progression of leukemia and may also make important contributions to targeted therapies in leukemia.