piR-823 contributes to colorectal tumorigenesis by enhancing the transcriptional activity of HSF1.

Piwi-interacting RNAs (piRNAs), a novel class of small non-coding RNAs, were first discovered in germline cells and are thought to silence transposons in spermatogenesis. Recently, piRNAs have also been identified in somatic tissues, and aberrant expression of piRNAs in tumor tissues may be implicated in carcinogenesis. However, the function of piR-823 in colorectal cancer (CRC) remains unclear. Here, we first found that piR-823 was significantly upregulated in CRC tissues compared with its expression in the adjacent tissues. Inhibition of piR-823 suppressed cell proliferation, arrested the cell cycle in the G1 phase and induced cell apoptosis in CRC cell lines HCT116 and DLD-1, whereas overexpression of piR-823 promoted cell proliferation in normal colonic epithelial cell line FHC. Interestingly, Inhibition of piR-823 repressed the expression of heat shock protein (HSP) 27, 60, 70. Furthermore, elevated HSPs expression partially abolished the effect of piR-823 on cell proliferation and apoptosis. In addition, we further demonstrated that piR-823 increased the transcriptional activity of HSF1, the common transcription factor of HSPs, by binding to HSF1 and promoting its phosphorylation at Ser326. Our study reveals that piR-823 plays a tumor-promoting role by upregulating phosphorylation and transcriptional activity of HSF1 and suggests piR-823 as a potential therapeutic target for CRC.

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.

A Single-Center Follow-Up Study of Low-Grade Gastric Intraepithelial Neoplasia and the Screening of Key Genes of Precancerous Lesions.

Objective: The study aimed to summarize the morphological characteristics of low-grade gastric intraepithelial neoplasia (LGIN) and explore its outcomes and risk factors. Additionally, it aimed to screen the core different expression genes (DEGs) of high-grade gastric intraepithelial neoplasia (HGIN) using bioinformatics methods to identify biomarkers for early gastric cancer outcomes. Methods: The clinical and pathological data of 449 patients with LGIN in the endoscopy center of the Second Hospital of Hebei Medical University from June 2013 to September 2018 were collected for retrospective analysis. The GSE130823 and GSE55696 data sets were selected from the Gene Expression Omnibus database, and the GEO2R tool was used to screen DEGs in HGIN and chronic gastritis tissue types. A DEG functional enrichment analysis was conducted using the Database for Annotation, Visualization, and Integrated Discovery. The STRING database was utilized to create a protein-protein interaction network, and the CytoHubba plug-in was used to screen the key genes of HGIN. Results: The incidence of LGIN increased with age, and most of the patients were aged between 45-59 years (P = 0.048). Lesions were found mainly in the cardia, mostly in people aged 60 (P < 0.05). Progression occurred in 42 of 449 patients, with a 9.4% rate of cancer development. Foci larger than 10 mm, ulcerative lesions, and an Helicobacter pylori-positive result were factors affecting the outcome of LGIN (P < 0.05). Seven core genes of HGIN were screened, including MYC, SOX2, CDX2, TBX3, KRT7, CDKN2A, and MUC5AC. Conclusion: The patients with LGIN reflected the potential for developing cancer. A magnifying gastroscope can contribute to the detection of early gastric cancer. Additionally, the MYC, CDX2, and TBX3 genes may act as specific biomarkers of HGIN.

Small RNA sequencing revealed aberrant piRNA expression profiles in colorectal cancer.

Piwi­interacting RNAs (piRNAs), a novel class of non­coding RNAs, are enriched in germ cells and implicated in spermatogenesis. Emerging evidence demonstrated deregulated expression of piRNAs in numerous tumor types. However, changes in piRNA expression profiles in colorectal cancer (CRC) have not yet been investigated. In the present study, small RNA sequencing was used to evaluate the differences in piRNA expression profiles between CRC and adjacent non­tumor tissues, as well as to screen for differentially expressed piRNAs. The present results demonstrated that the percentage of unique piRNA reads had no notable difference between the paired CRC and adjacent non­tumor samples (0.12% vs. 0.13%); however, the counts of total piRNA reads in CRC samples were increased, compared with those in adjacent non­tumor samples (0.15% vs. 0.07%). Differential expression analysis identified 33 upregulated piRNAs and 2 downregulated piRNAs in CRC samples, among which piR­18849, piR­19521 and piR­17724 were the top three upregulated piRNAs. Reverse transcription­quantitative polymerase chain reaction further confirmed that the expression levels of piR­18849, piR­19521 and piR­17724 were increased in 80 CRC tissues, compared with paired adjacent non­tumor tissues. Furthermore, the high expression of piR­18849 and piR­19521 was associated with a poor degree of differentiation. The increased expression of piR­18849 was also associated with high lymph node metastasis. However, no associations were determined between piR­17724 expression and clinicopathological characteristics of patients. In summary, the present study is the first to provide an overview of the changes in piRNA expression patterns in CRC, shedding new light on the regulatory roles of piRNAs in colorectal carcinogenesis. piR­18849 and piR­19521 may be prognostic biomarkers for patients with CRC.

Bile acid receptor TGR5 overexpression is associated with decreased intestinal mucosal injury and epithelial cell proliferation in obstructive jaundice.

Bile acids stimulate intestinal epithelial proliferation in vitro. We sought to investigate the role of the bile acid receptor TGR5 in the protection of intestinal epithelial proliferation in obstructive jaundice. Intestinal tissues and serum samples were obtained from patients with malignant obstructive jaundice and from bile duct ligation (BDL) rats. Intestinal permeability and morphological changes in the intestinal mucosa were observed. The functions of TGR5 in cell proliferation in intestinal epithelial injury were determined by overexpression or knockdown studies in Caco-2 and FHs 74 Int cells pretreated with lipopolysaccharide (LPS). Internal biliary drainage was superior to external biliary drainage in recovering intestinal permeability and mucosal histology in patients with obstructive jaundice. In BDL rats, feeding of chenodeoxycholic acid (CDCA) decreased intestinal mucosa injury. The levels of PCNA, a marker of proliferation, increased in response to CDCA feeding and were paralleled by elevated TGR5 expression. CDCA upregulated TGR5 expression and promoted proliferation in Caco-2 and FHs 74 Int cells pretreated with LPS. Overexpression of TGR5 resulted in increased PCNA, cell viability, EdU incorporation, and the proportion of cells in S phase, whereas knockdown of TGR5 had the opposite effect. Our data indicate that bile acids promote intestinal epithelial cell proliferation and decrease mucosal injury by upregulating TGR5 expression in obstructive jaundice.