Modeling of lactose enzymatic hydrolysis using Monte Carlo method

Background: Mathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule's spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications. Results: The enzyme hydrolysis of lactose, which is conformed to Michaelis­Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well. Conclusions: Monte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.

Noscapine inhibits migration of colon cancer SW480 cells by down-regulating Wnt3a/β-catenin signaling pathway and cadherin 17 / 中国肿瘤生物治疗杂志

@# Objective: To explore the effects of noscapine (Nos) on the expression of cadherin 17 (CDH17) in colon cancer SW480 cells and the mechanism of Nos on cell migration. Methods: SW480 cells were divided into the control group, empty vector (si-EV) group, CDH17 interference (si-CDH17) group, Nos treatment group, and CDH17 interference+Nos treatment (si-CDH17+Nos) group. Small interfering RNA (siRNA) was used to knockdown CDH17, and the selected concentration of Nos was (55.30±2.21) µg/ml (IC50). The mRNA expression of CDH17 was detected by qPCR; the apoptosis and migration abilities of SW480 cells were observed by Hoechst33258 staining and Transwell assay; the contents of VEGF, MMP2 and MMP9 in SW480 cells were measured by ELISA, and the protein expressions of CDH17, Wnt3a and β-catenin were determined by WB. Results: Compared with the control group, mRNA and protein expressions of CDH17 obviously decreased, cell apoptosis and migration significantly reduced, while the contents of VEGF, MMP2 and MMP9 as well as the protein expressions of Wnt3a and β-catenin significantly decreased in Nos treatment group, siCDH17 group and si-CDH17+Nos treatment group (all P<0.01).The effect of si-CDH17+Nos treatment was more significant than that of si-CDH17 (P<0.01). Conclusion: Nos induces apoptosis and inhibits the migration of human colon cancer SW480 cells, which may be related to the down-regulation of CDH17 expression and inhibition of the Wnt3a/β-catenin signaling pathway.