Melatonin Inhibit The Proliferation And Migration Of RKO Cells And The Molecular Mechanisms

Objective To study the effects of melatonin (Mel) on the proliferation and migration ofcolorectal cancer cell line RKO and the molecular mechanisms.Methods MTT assay was performed to measure the proliferation of RKO. Western blotwas done to detect the proteins associated with the endoplasmic reticulum stress (ERs)and apoptosis. Detect the reporters of melatonin. The effect of Mel on the migration ofRKO cells was analyzed by cell migration test and the expression of myosin light chainkinase (MLCK) and osteopontin (OPN) was detected by western blot. Detect the proteinwhich was related with mitogen activated protein kinase (MAPK) signal transductionpathway. Study the role of melatonin with the inhibitors and activators.Results Mel inhibited the proliferation and promoted the apoptosis in RKO. Heavychain binding protein (BIP) was up-regulated while C/EBP homologous protein (CHOP)and cysteinyl aspartate specific proteinase3(caspase3) were down-regulated in RKOcells treated with Mel. Mel can induce the expression of MT1and have no function toMT2. Mel also inhibited the cell migration and the expression of MLCK and OPN.Melatonin antineoplastic effect was related to up-regulate the phosphorylation of ERKand down-regulate the phosphorylation of p38and JNK.Conclusion Mel promotes the apoptosis of RKO cells by ERs and inhibits the migrationof RKO cells, which may be related to the down-regulation of the expression of MLCKand OPN. The function of melatonin was related with MAPK signal transductionpathway.