RECQL4 regulates DNA damage response and redox homeostasis in esophageal cancer

Objective:RECQL4(a member of the RECQ helicase family)upregulation has been reported to be associated with tumor progression in several malignancies.However,whether RECQL4 sustains esophageal squamous cell carcinoma(ESCC)has not been elucidated.In this study,we determined the functional role for RECQL4 in ESCC progression.Methods:RECQL4 expression in clinical samples of ESCC was examined by immunohistochemistry.Cell proliferation,cellular senescence,the epithelial-mesenchymal transition(EMT),DNA damage,and reactive oxygen species in ESCC cell lines with RECQL4 depletion or overexpression were analyzed.The levels of proteins involved in the DNA damage response(DDR),cell cycle progression,survival,and the EMT were determined by Western blot analyses.Results:RECQL4 was highly expressed in tumor tissues when compared to adjacent non-tumor tissues in ESCC(P<0.001)and positively correlated with poor differentiation(P=0.011),enhanced invasion(P=0.033),and metastasis(P=0.048).RECQL4 was positively associated with proliferation and migration in ESCC cells.Depletion of RECQL4 also inhibited growth of tumor xenografts in vivo.RECQL4 depletion induced G0/G1 phase arrest and cellular senescence.Importantly,the levels of DNA damage and reactive oxygen species were increased when RECQL4 was depleted.DDR,as measured by the activation of ATM,ATR,CHK1,and CHK2,was impaired.RECQL4 was also shown to promote the activation of AKT,ERK,and NF-k B in ESCC cells.Conclusions:The results indicated that RECQL4 was highly expressed in ESCC and played critical roles in the regulation of DDR,redox homeostasis,and cell survival.

Bimetallic sulfide FeS_(2)@SnS_(2) as high-performance anodes for sodium-ion batteries

A novel hierarchical structure of bimetal sulfide FeS_(2)@SnS_(2) with the 1D/2D heterostructure was developed for high-performance sodium-ion batteries(SIBs).The FeS_(2)@SnS_(2) was synthesized through a hydrothermal reaction and a sulphuration process.The exquisite 1D/2D heterostructure is featured with 2D SnS_(2) nanoflakes anchoring on the 1D FeS2 nanorod.This well-designed FeS_(2)@SnS_(2) provides shortened ion diffusion pathway and adequate surface area,which facilitates the Na+transport and capacitive Na+storage.Besides,the FeS_(2)@SnS_(2) integrates the 1D/2D synthetic structural advantages and synthetic hybrid active material.Consequently,the FeS_(2)@SnS_(2) anode exhibits high initial specific capacity of 765.5 mAh·g^(-1) at 1 A·g^(-1) and outstanding reversibility(506.0 mAh·g^(-1) at 1 A·g^(-1) after 200 cycles,262.5 mAh·g^(-1) at 5 A·g^(-1) after 1400 cycles).Moreover,the kinetic analysis reveals that the FeS_(2)@SnS_(2) anode displays significant capacitive behavior which boosts the rate capacity.