Objective:To investigate the effects of upregulation of cAMP response element binding protein (CREB) on proliferation, invasion and natural killer (NK) cell killing activity of esophageal adenocarcinoma.Methods:23 patients with esophageal cancer treated in Shaanxi Provincial People′s Hospital from March 2017 to December 2019 were selected. The protein expression of CREB in esophageal adenocarcinoma and adjacent normal tissues was detected by immunohistochemistry; Esophageal adenocarcinoma cell line TE-10 was cultured in vitro. TE-10 cells transfected with si-NC were set as the control group and TE-10 cells transfected with si-CREB were set as the si-CREB group. Western blot was used to detect the protein level of CREB, MHC class Ⅰ chain-related A (MICA) and MHC class Ⅰ chain-related B (MICB); Flow cytometry was employed to detect the expression of MICA and MICB; clone formation experiment and Transwell were used to detect the proliferative and invasive ability of TE-10 cells; lactate dehydrogenase (LDH) releasing assay was used to detect cytotoxicity of NK cells against TE-10 cells. Results:The expression of CREB in esophageal adenocarcinoma tissue was higher than that in normal tissues adjacent to cancer; the protein level of CREB in esophageal cancer cell TE-10 was higher than that of human normal esophageal epithelial cells HEEC ( P<0.05). The proliferative and invasive ability of TE-10 cells in the si-CREB group was significant lower than that in the control group ( P<0.05), while the expression of MICA and MICB, the killing rate of NK cells on TE-10 cells was significant higher than that in the control group ( P<0.05). Conclusions:CREB was highly expressed in esophageal adenocarcinoma tissues and cells. Silencing CREB could inhibit the proliferation and invasion of esophageal adenocarcinoma cells, and enhance the killing sensitivity of NK cells to esophageal adenocarcinoma cells by up-regulating the expression of MICA and MICB.

Objective To observe the therapeutic effect of curculioside on rats with ulcerative colitis(UC),and to explore its regulatory effect on the protein extracellular regulated kinases(PERK)/activated transcription factor 4(ATF4)/enhancer-binding protein(C/EBP)homologous protein(CHOP)pathway.Methods Sixty-one SD rats were induced by trinitrobenzene sulfonic acid(TNBS)to establish UC model.According to the random number table,they were divided into low,medium and high dose curculioside groups(25,50 and 100 mg/kg citronelioside dissolved in normal saline),mesalazine group(500 mg/kg mesalazine dissolved in normal saline),PERK inhibitor group(GSK2606414 1.0 mg/kg dissolved in normal saline),and model group(normal saline),and another 10 healthy SD rats were recorded as the normal group(normal saline),and the volume of normal saline was 1ml/100g the body weight of rats,gavaged once a day for 10 consecutive days.On the day after the end of administration,disease activity index(DAI)was evaluated.The ratio of lactulose(L)to mannitol(M)excretion rate(L/M)in the 5-hour urine of two groups of rats was determined by Gas chromatography(GC).Double antibody sandwich method was used to measure serum glucocorticoid concentration,and enzyme-linked immunosorbent assay was used to detect serum interleukin-6(IL-6),interferon-γ(IFN-γ),interleukin-8(IL-8)and tumor necrosis factor-α(TNF-α)levels.Hematoxylin eosin(HE)staining was used to observe the pathological changes of the intestinal mucosa.Real time reverse transcription fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to detect the expression of PERK,ATF4,CHOP,Bcl2 associated X protein(Bax),B lymphoblastoma 2(Bcl-2)messenger RNA(mRNA)in intestinal mucosa.Immunoblotting(WB)was used to detect the expression of PERK,ATF4,CHOP,Bax,and Bcl-2 proteins in intestinal mucosal tissue,as well as the levels of phosphorylated PERK(p-PERK).Results Visual and HE staining observations confirmed successful modeling.Compared with the normal group,the model group had L/M,DAI and intestinal mucosal pathological score,serum glucocorticoid concentration,and serum IL-6,IFN-γ,IL-8 and TNF-α levels,mRNA and protein expressions of PERK,ATF4,CHOP,Bax,and p-PERK increased(P＜0.05),while the mRNA and protein expressions of Bcl-2 decreased(P＜0.05).Compared with the model group,the L/M,DAI and intestinal mucosal pathological scores,serum glucocorticoid concentration,and serum IL-6,IFN-γ,IL-8 and TNF-αlevels,mRNA and protein expressions of PERK,ATF4,CHOP,Bax,and p-PERK of the three dose curculioside groups,mesalazine group,and PERK inhibitor group decreased(P＜0.05),while the mRNA and protein expressions of Bcl-2 increased(P＜0.05).There were no significant differences in glucocorticoid concentration,PERK,ATF4,CHOP,Bax,Bcl-2 mRNA and protein expressions,p-PERK levels between the low dose curculioside group and the mesalazine group,between the medium dose curculioside group and the PERK inhibitor group(P＞0.05),and there were significant differences between each other two groups(P＜0.05).The pathological changes of colonic mucosa in the model group were serious.The low dose curculioside group was relieved,the medium dose curculioside group,the Mesalazine group and the PERK inhibitor group were significantly relieved,and the high-dose group of citronelloside was significantly relieved.Conclusion Curculioside can improve intestinal mucosal barrier function,control disease activity,and alleviate pathological changes in UC rats,which is speculated to be related to the inhibition of the PERK/ATF4/CHOP pathway.