REC8 promotes tumor migration, invasion and angiogenesis by targeting the PKA pathway in hepatocellular carcinoma.

REC8 is a member of the cohesin family, and its abnormal activation has been detected in cancer cells. This study explored the role and possible mechanism of REC8 in hepatocellular carcinoma (HCC). A total of 40 pairs of HCC and adjacent tissues were collected, and the clinical significance of REC8 expression in HCC was evaluated. REC8 expression in human HCC tissues and HCC cell lines was investigated by quantitative real-time PCR, Western blotting, immunohistochemistry and immunofluorescence staining. The biological functions of REC8 in HCC cell lines were detected by wound-healing assay, Matrigel invasion assay and tube formation assay. The proteins interacting with REC8 were identified by mass spectrometry after immunoprecipitation screening. There was a correlation between the high expression of REC8 and positive alpha-fetoprotein levels. The expression level of REC8 protein in HCC tissues was higher than that in adjacent tissues. REC8 has mainly located in the nucleus of HCC tissue cells and HCC cell lines, but it was expressed in the cytoplasm of adjacent normal tissue cells and hepatocytes. The results of wound healing, transwell invasion and tubular formation assays indicated that the overexpression of REC8 accelerated the metastasis of HCC in vitro; however, metastasis was suppressed after REC8 was silenced by small interference RNA. A total of 57 differentially expressed proteins were identified by mass spectrometry, and it was found that REC8 and PKA RII-α staining was colocalized in the nucleus. The expression levels of MMP-9 and VEGF-C were decreased after treatment with the PKA inhibitor H89. Overall, REC8 promotes the migration, invasion and angiogenesis of HCC cells through the PKA pathway.

TGR5 promotes cholangiocarcinoma by interacting with mortalin.

Takeda-G-protein-receptor-5 (TGR5) is a G-protein-coupled receptor (GPCR) activated by bile acids, and mortalin is a multipotent chaperone of the HSP70 family. In the present study, TGR5 was detected by immunohistochemistry (IHC) in extrahepatic cholangiocarcinoma (ECC) specimens, and TGR5 expression in ECC tissues and adjacent tissues was compared. In vitro TGR5 was overexpressed and knocked down in human intrahepatic cholangiocarcinoma (ICC) cell line RBE and human extrahepatic cholangiocarcinoma (ECC) cell line QBC-939 to observe its effects on the biological behavior of cholangiocarcinoma (CC) cells, including proliferation, apoptosis and migration. In vivo xenograft model was constructed to explore the role of TGR5 in CC growth. Proteins that interacted with TGR5 were screened using an immunoprecipitation spectrometry approach, and the identified protein was down-regulated to investigate its contribution to CC growth. The present study demonstrated that TGR5 is highly expressed in CC tissues, and strong TGR5 expression may indicate high malignancy in CC. Furthermore, TGR5 promotes CC cell proliferation, migration, and apoptosis resistance. TGR5 boosts CC growth in vivo. In addition, TGR5 combines with mortalin and regulates mortalin expression in the CC cell line. Mortalin participates in the TGR5-induced increase in CC cell proliferation. In conclusion, TGR5 is of clinical significance based on its implications for the degree of malignancy in patients with CC. Mortalin may be a downstream component regulated by TGR5, and TGR5 promotes cholangiocarcinoma at least partially by interacting with mortalin and upregulating its expression. Both TGR5 and mortalin are positive regulators, and may serve as potential therapeutic targets for CC.

Impacts of terrain attributes and human activities on soil texture class variations in hilly areas, south-west China.

Knowledge of soil texture variations is critical for agricultural and engineering applications because texture influences many other soil properties. This study used random forest method to evaluate the effects of human activities and topographic parameters on the spatial variability of soil texture in hilly areas where soil parent material was uniform. The study site covers 252 km2 and is located in the Upper Yangtze River Basin of south-west China. A total of 3636 samples were collected from the cultivated soils at a depth of 20 cm of dryland (sloping field and terraced land) landscape. The soil texture class for each sample was estimated by experienced soil scientists in the field. Two soil texture classes (loam and clay) were observed in the watershed. Eleven terrain parameters were derived from a digital elevation model with a resolution of 30 m. Compared with loamy soils, clayey soils were mostly observed in the areas with lower elevation and gentle slopes. The outcome of random forest indicated that human activities and elevation had strong effects on soil texture class variations across the study site. Further results showed that the relative importance of terrain parameters to soil texture class variations varied with dryland landscape. Topographic wetness index and elevation were the most important variables for sloping field and terraced land landscapes, respectively.

Knockdown of Astrocyte Elevated Gene-1 Inhibits Activation of Hepatic Stellate Cells.

BACKGROUND: Astrocyte elevated gene-1 (AEG-1) is a positive regulator of tumorigenesis and a valuable prognostic marker of a diverse array of cancers, including liver cancer; however, the relationship between AEG-1 and hepatic fibrogenesis is not known. OBJECTIVE: The objective of this study was to explore the expression of AEG-1 during hepatic fibrogenesis and determine how AEG-1 regulates the profibrogenic phenotype of hepatic stellate cells (HSCs). METHODS: The levels of AEG-1 were monitored in the fibrotic livers and transforming growth factor-ß (TGF-ß)- or lipopolysaccharide (LPS)-stimulated HSCs. The expression of AEG-1 was knocked down by lentivirus-mediated short hairpin RNA in HSCs, and collagen expression, proliferation assays, apoptosis induction studies, and migration assays were simultaneously conducted in vitro. RESULTS: AEG-1 expression was increased in the fibrotic livers. At the cellular level, TGF-ß or LPS stimulation, which caused HSC activation, induced AEG-1 expression in HSC-T6 and primary rat HSCs (P < 0.05). Knockdown of AEG-1 inhibited collagen I and α-smooth muscle actin expression (P < 0.05), reduced cell proliferation (P < 0.05) and motility (P < 0.05), and induced cell apoptosis (P < 0.05) in HSCs. This antifibrotic effect caused by lack of AEG-1 was associated with the inactivation of PI3K/Akt and the mitogen-activated protein kinase pathway. CONCLUSIONS: Knockdown of AEG-1 suppressed the activation of HSCs by modulating the phenotype and inducing apoptosis. AEG-1 might be a potential target in treatment of hepatic fibrosis.