rSjP40 suppresses hepatic stellate cell activation by promoting microRNA-155 expression and inhibiting STAT5 and FOXO3a expression.

Activation of hepatic stellate cells (HSCs) is the central event of the evolution of hepatic fibrosis. Schistosomiasis is one of the pathogenic factors which could induce hepatic fibrosis. Previous studies have shown that recombinant Schistosoma japonicum egg antigen P40 (rSjP40) can inhibit the activation and proliferation of HSCs. MicroRNA-155 is one of the multifunctional noncoding RNA, which is involved in a series of important biological processes including cell development, proliferation, differentiation and apoptosis. Here, we try to observe the role of microRNA-155 in rSjP40-inhibited HSC activation and explore its potential mechanisms. We found that microRNA-155 was raised in rSjP40-treated HSCs, and further studies have shown that rSjP40 enhanced microRNA-155 expression by inhibiting STAT5 transcription. Up-regulated microRNA-155 can down-regulate the expression of FOXO3a and then participate in rSjP40-inhibited expression of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, we observed microRNA-155 inhibitor could partially restore the down-regulation of FOXO3a, α-SMA and collagen I expression in LX-2 cells induced by rSjP40. Therefore, our research provides further insight into the mechanism by which rSjP40 could inhibit HSC activation via miR-155.

Chinese 1 strain of Toxoplasma gondii excreted-secreted antigens negatively modulate Foxp3 via inhibition of the TGFßRII/Smad2/Smad3/Smad4 pathway.

Toxoplasma gondii is an opportunistic intracellular parasite and is considered an important aetiological factor in the process of abortion, especially as occurs in early gestation. Chinese 1 strain of T. gondii is a dominant genotype prevalent in China. Although it is known that early foetal resorption triggered by RH strain of T. gondii is attributable to immune mechanisms rather than its direct effect in uterus, the underlying mechanism of the abortion caused by Chinese 1 strain remains unclear. This study was designed to investigate the effect of excreted-secreted antigens (ESA) of Chinese 1 strain of T. gondii on the expression of forkhead box transcription factor (Foxp3) as it pertains to early pregnancy and abortion. ESA caused a marked inhibition in the expression of Foxp3 both in vivo and in vitro. In addition, ESA negatively modulated Smad2 and Smad3 at the posttranslational level. Smad2 siRNA cooperated with ESA to further suppress the level of Foxp3. This inhibitory effect on Foxp3 expression was partially abrogated by overexpression of Smad2, Smad3 and Smad4. Additionally, ESA attenuated the expression of TGFßRII, whereas TGFßRII agonist could profoundly reversed the decreased Foxp3 triggered by ESA. Collectively, the findings suggested that ESA restricted Foxp3 expression by inhibiting TGFßRII/Smad2/Smad3/Smad4 signalling, ultimately resulting in abortion.

Improving the overall survival prognosis prediction accuracy: A 9-gene signature in CRC patients.

Colorectal cancer (CRC) is a malignant tumor and morbidity rates are among the highest in the world. The variation in CRC patients' prognosis prompts an urgent need for new molecular biomarkers to improve the accuracy for predicting the CRC patients' prognosis or as a complement to the traditional TNM staging for clinical practice. CRC patients' gene expression data of HTSeq-FPKM and matching clinical information were downloaded from The Cancer Genome Atlas (TCGA) datasets. Patients were randomly divided into a training dataset and a test dataset. By univariate and multivariate Cox regression survival analyses and Lasso regression analysis, a prediction model which divided each patient into high-or low-risk group was constructed. The differences in survival time between the two groups were compared by the Kaplan-Meier method and the log-rank test. The weighted gene co-expression network analysis (WGCNA) was used to explore the relationship between all the survival-related genes. The survival outcomes of patients whose overall survival (OS) time were significantly lower in the high-risk group than that in the low-risk group both in the training and test datasets. Areas under the ROC curves which termed AUC values of our 9-gene signature achieved 0.823 in the training dataset and 0.806 in the test dataset. A nomogram was constructed for clinical practice when we combined the 9-gene signature with TNM stage and age to evaluate the survival time of patients with CRC, and the C-index increased from 0.739 to 0.794. In conclusion, we identified nine novel biomarkers that not only are independent prognostic indexes for CRC patients but also can serve as a good supplement to traditional clinicopathological factors to more accurately evaluate the survival of CRC patients.

Transcriptional information underlying the generation of CSCs and the construction of a nine-mRNA signature to improve prognosis prediction in colorectal cancer.

BACKGROUND: Despite recent progress in screening survival-related genes, there have been few attempts to apply methods based on cancer stem cells (CSCs) for prognosis. We aimed to identify a CSC-based model to predict survival in colorectal cancer (CRC) patients. MATERIAL/METHODS: Differentially expressed genes between CRC and normal tissues and between CD133- and CD133+ cells were obtained from The Cancer Genome Atlas and Gene Expression Omnibus, and intersections were evaluated. Gene Ontology functional and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyzes were performed. STRING was used to investigate interactions between the encoded proteins and the Kaplan-Meier method to verify mRNAs associated with survival. A prognostic model based on CSCs was established via univariate and multivariate Cox regression. Receiver operating characteristic curve analysis was conducted to test the model's sensitivity and specificity. The KS test was applied to provide evidence for relationships between expression levels of nine mRNAs in our model and pathological stage. RESULTS: In total, 155 common differentially expressed mRNAs were identified, and nine (AOC1, UCN, MTUS1, CDC20, SNCB, MAT1A, TUBB2B, GABRA4 and ALPP) were screened after regression analyses to establish a predictive model for classifying patients into high- and low-risk groups with significantly different overall survival times, especially for stage II and IV patients. CONCLUSIONS: We developed a novel model that provides additional and powerful prognostic information beyond conventional clinicopathological factors for CRC survival prediction. It also provides new insight into the molecular mechanisms underlying the transition from normal tissues to CSCs and formation of tumor tissues.

MiR-92a promotes the invasion and migration of colorectal cancer by targeting RECK.

The up-regulation of miR-92a in human cancer happens frequently, and is related to an increase of metastasis and decreased survival. However, its functions in colorectal cancer (CRC) are largely unknown. This study aimed to investigate the regulatory effect of miR-92a on cell invasion and migration in colorectal cancer (CRC). A total of 158 patients with CRC were included, and in situ hybridization was used to predict the expression of miR-92a in the paraffin sections from the patients. Quantitative reverse transcription PCR was used to detect the expression of miR-92a and its target gene. Protein levels were determined by western blotting. Luciferase assays confirmed the direct target of miR-92a. Furthermore, cell invasion and migration were detected using Transwell and wound healing assays. The expression level of miR-92a in tumor tissues was upregulated compared with that of paired normal tissues and negatively correlated with the RECK protein level. The 3-year disease-free survival (DFS) and overall survival (OS) rates of miR-92a expression in the high group were significantly lower than those in the miR-92a-low group. The RECK 3'-UTR reporter activity assay suggested that the RECK gene was a direct target of miR-92a. After transfection of the miR-92a-mimic, the miR-92a levels were increased in HCT116 and SW620 cell lines, while the protein expression of RECK was decreased instead of the mRNA level, along with downregulation of matrix metalloproteinase (MMP) protein expression. Conversely, after transfection with miR-92a-inhibitor, the opposite trend was achieved. In conclusion, miR-92a promotes the invasion and migration of CRC through the RECK-MMP signaling pathway, and the upregulation of miR-92a was associated with poor long-term prognosis in CRC.

Recombinant SjP40 protein enhances p27 promoter expression in hepatic stellate cells via an E2F1-dependent mechanism.

The p27 protein plays a critical role in cell cycle arrest. Our previous studies have demonstrated that recombinant P40 protein from Schistosoma japonicum (rSjP40) could induce G1 phase arrest of cell cycle. We, therefore, attempted to observe the effect of rSjP40 on p27 promoter activity in LX-2 cells and to explore its potential mechanisms in this study. Using both Western blot and dual-luciferase reporter assay, we demonstrated that rSjP40 could enhance the expression of p27 in LX-2 cells. Results obtained using truncated fragments of p27 promoter showed that rSjP40 increased p27 promoter activity in LX-2 cells, mainly via some transcription factors that bind to the -1740/-873 region of p27 promoter. Further studies confirmed that the enhancement of p27 promoter activity induced by rSjP40 was related to E2F1 in LX-2 cells. Transfection of siRNA of E2F1 could also restore the effect of rSjP40 on expression of p27 and partially on α-SMA. Therefore, our study provided further insights into the mechanism by which rSjP40 induces LX-2 cell cycle arrest at G1 phase and inhibits HSC activation. Our results provide basis for future study of the blocking effect of rSjP40 in liver fibrosis.