Association between green tea intake and digestive system cancer risk in European and East Asian populations: a Mendelian randomization study.

PURPOSE: Previous observational studies have shown that green tea consumption is associated with a reduced incidence of digestive system cancers (DSCs). However, the observed association could be due to confounding factors. Therefore, we used a two-sample Mendelian randomization (MR) approach to assess the causal effect of green tea intake on the risk of five common DSCs. METHODS: Independent genetic variants strongly associated with green tea consumption in European and East Asian populations were selected as instrumental variables in genome-wide association studies involving up to 64,949 European individuals and 152,653 East Asian individuals, respectively. The associations between genetic variants and DSCs were extracted from the FinnGen study and the Japan Biobank. The primary analysis was performed using random-effects inverse variance weighting (IVW). Other MR analyses, including weighted mode-based estimate, weighted-median, MR-Egger regression, Mendelian Randomization-Pleiotropy Residual Sum and Outlier (MR-PRESSO) analysis, were used for sensitivity analyses. In addition, a multivariate MR design was performed to adjust for smoking and alcohol consumption. RESULTS: The IVW results showed no causal relationship between tea intake and DSCs risk in European population (esophagus cancer: odds ratio (OR) = 1.044, 95% confidence interval (CI) 0.992-1.099, p = 0.096; stomach cancer: OR = 0.988, 95% CI 0.963-1.014, p = 0.368; colorectal cancer: OR = 1.003, 95% CI 0.992-1.015, p = 0.588; liver cancer: OR = 0.996, 95% CI 0.960-1.032, p = 0.808; pancreatic cancer: OR = 0.990, 95% CI 0.965-1.015, p = 0.432). The MR-Egger regression, MR-PRESSO analysis and other methods also confirmed the reliability of the conclusion. Similarly, no significant association was found between green tea consumption and the incidence of DSCs among East Asians. This relationship is not significant even after adjusting for smoking and alcohol consumption (P > 0.05). CONCLUSION: Our study provides evidence that genetically predicted green tea intake is not causally associated with the development of DSCs in the European and East Asian population.

[Application of time domain reflectometry for determination of wate content in Xiangsha Yangwei pills].

Xiangsha Yangwei pill was selected as a model drug in this research, and time domain reflectometry (TDR) was used to determine the water content in the pill. The effects of five factors including the number of pill layers, pill packing density, atmospheric moisture, ambient temperature and the ratio of pill formula were investigated on water content. The results showed that the number of pill layers and ambient temperature had significant effects on water content of pills, while the pill packing density, atmospheric moisture and pill formula ratio had little effect on the determination of water content in pills. The reflection value was stable when 6 layers of pills were used. Under the condition of 25 ℃ and 45% relative humidity, the water content of pills ranged from 4.01% to 22.38%, showing good linear relationship between water content and reflection value, and the model equation was as follows: Y=0.279X－21.670 (R²=0.997 0). Verification experiment was used to explain the feasibility of this prediction model. The precision of the method complied with the methodology standard. It is concluded that TDR can be used in determination of water content in Xiangsha Yangwei pills. Additionally, TDR, as a new way to quickly and efficiently determine the water content, has a prospect application in the processing of traditional Chinese medicine pharmacy, especially for concentrated pill.

Connective tissue growth factor is overexpressed in human hepatocellular carcinoma and promotes cell invasion and growth.

AIM: To determine the expression characteristics of connective tissue growth factor (CTGF/CCN2) in human hepatocellular carcinoma (HCC) in histology and to elucidate the roles of CCN2 on hepatoma cell cycle progression and metastasis in vitro. METHODS: Liver samples from 36 patients (who underwent hepatic resection for the first HCC between 2006 and 2011) and 6 normal individuals were examined for transforming growth factor ß1 (TGF-ß1) or CCN2 mRNA by in situ hybridization. Computer image analysis was performed to measure integrated optimal density of CCN2 mRNA-positive cells in carcinoma foci and the surrounding stroma. Fibroblast-specific protein-1 (FSP-1) and E-cadherin were examined to evaluate the process of epithelial to mesenchymal transition, α-smooth muscle actin and FSP-1 were detected to identify hepatic stellate cells, and CD34 was measured to evaluate the extent of vascularization in liver tissues by immunohistochemical staining. CCN2 was assessed for its stimulation of HepG2 cell migration and invasion using commercial kits while flow cytometry was used to determine CCN2 effects on HepG2 cell-cycle. RESULTS: In situ hybridization analysis showed that TGF-ß1 mRNA was mainly detected in connective tissues and vasculature around carcinoma foci. In comparison to normal controls, CCN2 mRNA was enhanced 1.9-fold in carcinoma foci (12.36 ± 6.08 vs 6.42 ± 2.35) or 9.4-fold in the surrounding stroma (60.27 ± 28.71 vs 6.42 ± 2.35), with concomitant expression of CCN2 and TGF-ß1 mRNA in those areas. Epithelial-mesenchymal transition phenotype related with CCN2 was detected in 12/36 (33.3%) of HCC liver samples at the edges between carcinoma foci and vasculature. Incubation of HepG2 cells with CCN2 (100 ng/mL) resulted in more of the cells transitioning into S phase (23.85 ± 2.35 vs 10.94 ± 0.23), and induced a significant migratory (4.0-fold) and invasive (5.7-fold) effect. TGF-ß1-induced cell invasion was abrogated by a neutralizing CCN2 antibody showing that CCN2 is a downstream mediator of TGF-ß1-induced hepatoma cell invasion. CONCLUSION: These data support a role for CCN2 in the growth and metastasis of HCC and highlight CCN2 as a potential novel therapeutic target.