Aloin inhibits gastric cancer cell proliferation and migration by suppressing the STAT3/HMGB1 signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the molecular mechanism underlying the inhibitory effect of aloin on the proliferation and migration of gastric cancer cells.@*METHODS@#Human gastric cancer MGC-803 cells treated with 100, 200 and 300 μg/mL aloin were examined for changes in cell viability, proliferation and migration abilities using CCK-8, EdU and Transwell assays. HMGB1 mRNA level in the cells was detected with RT-qPCR, and the protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 were determined using Western blotting. JASPAR database was used to predict the binding of STAT3 to HMGB1 promoter. In a BALB/c-Nu mouse model bearing subcutaneous MGC-803 cell xenograft, the effect of intraperitoneal injection of aloin (50 mg/kg) on tumor growth was observed. The protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 in the tumor tissue was examined using Western blotting, and tumor metastasis in the liver and lung tissues was detected using HE staining.@*RESULTS@#Treatment with aloin concentration-dependently inhibited the viability of MGC-803 cells (P < 0.05), significantly reduced the number of EdU-positive cells (P < 0.01), and attenuated the migration ability of the cells (P < 0.01). Aloin treatment dose-dependently down-regulated HMGB1 mRNA expression (P < 0.01), lowered the protein expressions of HMGB1, cyclin B1, cyclin E1, MMP-2, MMP-9 and p-STAT3, and up-regulated E-cadherin expression in MGC-803 cells. Prediction based on JASPAR database suggested that STAT3 could bind to the promoter region of HMGB1. In the tumor-bearing mice, aloin treatment significantly reduced the tumor size and weight (P < 0.01), lowered the protein expressions of cyclin B1, cyclin E1, MMP-2, MMP-9, HMGB1 and p-STAT3 and increased the expression of E-cadherin in the tumor tissue (P < 0.01).@*CONCLUSION@#Aloin attenuates the proliferation and migration of gastric cancer cells by inhibiting the STAT3/HMGB1 signaling pathway.

A dual-signal sensor for the analysis of parathion-methyl using silver nanoparticles modified with graphitic carbon nitride / 药物分析学报

A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluo-rimetric determination of organophosphorus pesticides(OPs).This method used silver nanoparticles(AgNPs)modified with graphitic carbon nitride(g-C3N4).The AgNPs reduced the fluorescence intensity of g-C3N4.Acetylthiocholine(ATCh)could be catalytically hydrolyzed by acetylcholinesterase(AChE)to form thiocholine,which induces aggregation of the AgNPs.This aggregation led to the recovery of the blue fluorescence of g-C3N4,with excitation/emission peaks at 310/460 nm.This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE.The degree of reduction was found to be proportional to the concentration of OPs,and the limit of fluorometric detection was 0.0324 μg/L(S/N = 3).In addition,the absorption of the g-C3N4/AgNPs at 390 nm decreased because of the aggregation of the AgNPs,but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs.This method was successfully applied to the analysis of parathion-methyl in real samples.