Effect Of Outer Membrane Vesicles Derived From Escherichia Coli On Proliferation,Apoptosis And Migration Of Human Neuroblastoma SK-N-SH Cells In Vitro

Objective: To investigate the effect of outer membrane vesicles derived from Escherichia coli on proliferation,apoptosis and migration of human neuroblastoma SK-N-SH cells in vitro.Methods: The outer membrane vesicles(OMVs)were obtained from wild-type Escherichia coli with ultracentrifugation method,and the morphology of the OMVs was observed by transmission electron microscopy and the vesicle diameter was determined using MALVERN ZEN3690.Human neuroblastoma SK-N-SH cells were treated with the OMVs at low(100 μg/mL),moderate(500 μg/mL)and high(1000 μg/mL)doses,and 24,48 and 72 h later,the cell proliferation activity was detected with MTT assay.The expressions of apoptosisrelated marker caspase-3 was detected using Western blotting,and TUNEL assay was performed to detect the cell apoptosis.The migration capacity of SK-N-SH cells was evaluated using Transwell migration assay.Results: The isolated OMVs showed a circular or elliptical hollow structure with double-layer membrane with a diameter range of 30-450 nm.Compared with control cells,SK-N-SH cells treated with the OMVs showed significantly lowered cell proliferation capacity with enhanced expression of caspase-3.Treatment of the cells with the OMVs resulted in increased cell apoptosis and significantly lowered migration capacity(P<0.05).Conclusion: The OMVs derived from Escherichia coli can produce cytotoxicity against SK-N-SH cells and might serve as a therapeutic agent for refractory neuroblastoma.