Inactivation of ATF-2 enhances epithelial-mesenchymal transition and gemcitabine sensitivity in human pancreatic cancer cells.

OBJECTIVE: This work aimed to study the activating transcription factor 2 or AMP-dependent transcription factor-2 (ATF-2) inhibition mediated gemcitabine sensitivity in human pancreatic cancer cells. METHODS: The protein and messenger RNA expressions of ATF-2 in 42 pancreatic cancer tissues and adjacent nontumorous tissues were detected. Kaplan-Meier survival analysis was performed based on the expression level of ATF-2 protein in tumor tissues. Then the pancreatic cancer cells were transduced with ATF-2-expressing lentivirus and small interfering RNAs (siRNAs) to investigate the effect of ATF-2 on pancreatic cancer cell invasion, epithelium to mesenchyme transition, apoptosis, and gemcitabine sensitivity. RESULTS: The expression of phosphorylated (p)-ATF-2 protein was upregulated in pancreatic cancer tissues compared with adjacent nontumorous tissues. Patients with relative higher p-ATF-2 level showed significantly lower survival time. Then we found that the transfection ATF-2 siRNA into BxPC3 cells inhibited cell proliferation, invasion, and epithelium to mesenchyme transition, but enhanced cell apoptosis. These changes could be enhanced by the additional administration of gemcitabine. In addition, we confirmed that the overexpression of ATF-2 in Panc-1 cells promoted cell invasion and epithelium to mesenchyme transition. CONCLUSION: We concluded that inhibition-promoted ATF-2 expression was responsible for epithelium to mesenchyme transition and invasion of pancreatic cancer cells, while the inhibition of ATF-2 confers to gemcitabine sensitivity in human pancreatic cancer cells in vitro.

Environmental Regulation, Resource Misallocation, and Total Factor Productivity: An Empirical Analysis Based on 284 Cities at the Prefecture-Level and Above in China.

We investigated the impact of environmental regulation on total factor productivity (TFP) based on a panel dataset of 284 cities at the prefecture-level and above in mainland China from 2006 to 2020 and examined whether environmental regulation had a resource reallocation effect and thus affected TFP. The results showed that there was an "inverted U-shaped" pattern in the impact of environmental regulation on TFP in China and a moderate strengthening of environmental regulation helped to increase TFP, which still held after endogeneity treatment and robustness tests. The "inverted U-shaped" relationship between environmental regulation and TFP in eastern, central, and western cities still held, while environmental regulation did not produce significant effects on TFP in the northeast. The effect of environmental regulation on TFP in large, medium, and small cities tested in groups by city size was consistent with the full sample findings, but the effects decreased in a gradient with city size. The analysis of the impact mechanism showed that environmental regulation had a suppressive effect on resource misallocation and could generate a positive resource reallocation effect and enhance city TFP. The labor reallocation effect of environmental regulation for TFP was stronger than the capital reallocation effect. The findings of our study are of policy reference value for optimizing resource allocation through environmental regulation and thus promoting high-quality city development in China.

[Effect on bioactive components of Xuesaitong injection in the process of ultra-filter].

OBJECTIVE: To study the effect on bioactive components of Xuesaitong injection in the process of ultra-filter by orthogonal test. METHODS: The change of the contents of active components was examined by HPLC method, using notoginsennoside R1 , ginsennoside Rg1, ginsennoside Rb1 and ginsennoside Rd as the mark components. The effect of the transmissivity of active components was studied with four different membrane parameters (such as pore diameter of membrane, operational pressure, the temperature and the concentration of the officinal liquid) by orthogonal test. RESULTS: In the process of ultra-filter the transmissivity of notoginsennoside R, and ginsennoside Rg, had the same characteristics. Both of the average transmissivities of these two components were in the range of 45% to 95%. The concentration of the officinal liquid showed significant influence. The transmissivities of ginsennoside Rb, and ginsennoside Rd in the process of ultra-filiter had the same characteristic. The average transmissivities of these two components were in the range of 2 8%-62% and 1.8%-45%, respectively. The pore diameter of membrane and the temperature showed significant influence. The concentration of the officinal liquid also showed significant influence on the transmissivity of ginsennoside Rd. CONCLUSION: This study provides an external direction for the preparation of Xuesaitong injection.