Erector spinae plane block(ESPB)is a fascia plane block technique that involves injecting local anesthetics between the erector spinae muscle and the transverse processes of the spine.It blocks the posterior branches of the spinal nerves to provide perioperative analgesia for spinal surgeries.In recent years,ESPB has been increasingly widely used in spinal surgery analgesia due to its relatively simple operation,high safety and significant clinical benefits.However,its mechanism of action and the best application strategy still need to be further explored.This article systematically reviews the anatomical basis,mechanism of action,op-eration methods,drug selection,analgesic effect in various spinal surgeries,comparative advantages with other commonly used analgesic methods,and potential complications of ESPB,aiming to provide a reference for the clinical application of ESPB.

Background and aims:Hepatocellular carcinoma(HCC)is a malignant tumor with a high mortality rate,but there are still no effective treatments.The aim of this study was to investigate the anticancer po-tential of the combined use of brefeldin A(BFA)and tunicamycin(TM)in HepG2 cells,as well as the underlying mechanisms.Methods:HepG2 cells were treated with different concentrations of BFA(0.1-2.5 mg/L)and TM(1-5 mg/L)for 24 h.DMSO(0.1％,v/v)was used as a vehicle control.Cell viability and cell migration were measured using MTT assay and scratch wound assay,respectively.Apoptosis was detected using flow cytometry and acridine orange(AO)staining.The protein and mRNA levels of various factors involved in apoptosis(poly(ADP-ribose)polymerase-1(PARP-1),caspase-12,caspase-3,and stearoyl-CoA desaturase 1)and endoplasmic reticulum(ER)stress(binding immunoglobulin protein(BiP),protein kinase R-like endoplasmic reticulum kinase(PERK),p-PERK,phosphorylation of eukaryotic translation initiation factor 2alpha(p-eIF2α),activating transcription factor(ATF)4,and C/EBP homologous protein(CHOP))were measured using Western blotting and qRT-PCR,respectively.Results:Both BFA and TM alone significantly reduced the viability of HepG2 cells in a dose-dependent way.The co-incubation with TM(1 mg/L)further significantly reduced the viability of HepG2 cells treated with BFA(0.25 mg/L)alone(P＜0.05).BFA significantly increased the protein and mRNA levels of caspase-3 and PARP-1(P＜0.05)compared to control and DMSO-treated cells,indicating that BFA induced apoptosis in HepG2 cells by increasing the expression of caspase-3 and PARP-1.The induction of apoptosis by BFA could be further significantly enhanced by co-incubation with TM.In addition,BFA significantly increased the mRNA levels of BiP,PERK and ATF4(P＜0.05)compared to control and DMSO-treated cells.After co-incubation of BFA and TM,the protein levels of BiP,p-PERK,p-eIF2α and CHOP were significantly increased,indicating that TM could enhance BFA-induced ER stress in HepG2 cells through the PERK-eIF2α-ATF4-CHOP pathway.Conclusions:BFA could induce apoptosis and ER stress,and TM could enhance the ability of BFA to induce apoptosis and ER stress in HepG2 cells through the PERK-eIF2α-ATF4-CHOP pathway.The findings highlight the therapeutic potential of the combined use of BFA and TM in treating HCC.