Methylation analysis of CXCR1 in mammary gland tissue of cows with mastitis induced by Staphylococcus aureus.

Mastitis is the most important disease in the global dairy industry, and causes large economic losses. Staphylococcus aureus is one of most common pathogens that cause bovine mastitis. CXCR1 has been implicated as a prospective genetic marker for mastitis resistance in dairy cows; CXCR1 expression significantly increases when cows have mastitis. To investigate the mechanisms involved in its increased expression, bisulfite sequencing polymerase chain reaction (PCR) was used to detect the methylation status of CXCR1 CpG island, and quantitative fluorescence PCR was used to detect CXCR1 expression in bovine mammary tissue induced with S. aureus in three Chinese Holstein cows. No CpG island was found for bovine CXCR1 in the upstream 2-kb region, whereas one CpG island that contained 13 CpG sites was found in exon 1 of CXCR1. All of the CpG sites were under hypermethylation from 90 to 100% in the mammary tissues. When the mammary gland mRNA expression of CXCR1 was 12.10-fold higher in infected cow quarters than in uninfected quarters, the methylation levels of the CpG site at position 519 were significantly lower in the infected quarters than in the uninfected quarters. Pearson correlation analysis showed that the methylation level at position 519 was significantly negatively correlated with the CXCR1 mRNA expression level (P < 0.05). These results indicate that the methylation of the CpG site at position 519 may regulate CXCR1 expression in cows with mastitis induced by S. aureus, but further studies are needed to elucidate the mechanisms involved.

LncRNA-NEF inhibits proliferation, migration and invasion of esophageal squamous-cell carcinoma cells by inactivating wnt/ß-catenin pathway.

OBJECTIVE: Our study aimed to investigate the role of lncRNA-Neighboring Enhancer of FOXA2 (NEF) in esophageal squamous-cell carcinoma. PATIENTS AND METHODS: Tumor tissues and adjacent tissues were obtained from esophageal squamous-cell carcinoma patients, and blood samples were extracted from both patients with esophageal squamous-cell carcinoma and healthy volunteers. The expression of NEF was detected by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). All patients were followed-up for 5 years and ROC curve analysis and survival analysis were performed to evaluate the diagnostic and prognostic values of serum NEF for esophageal squamous-cell carcinoma. NEF expression vector was transfected into cells of esophageal squamous-cell carcinoma cell lines. Cell proliferation, migration and invasion were detected by CCK-8 assay, transwell migration assay, and transwell invasion assay, respectively. The interaction between NEF and wnt/ß-catenin pathway were explored by Western blot and qRT-PCR. RESULTS: Expression of NEF was significantly downregulated in tumor tissues than in adjacent tissues in most patients. Serum level of NEF was higher in esophageal squamous-cell carcinoma patients than in healthy controls, and was significantly correlated with tumor size and tumor distant tumor metastasis. Serum NEF is a promising diagnostic and prognostic marker for esophageal squamous-cell carcinoma. NEF overexpression inhibited cancer cell proliferation, migration and invasion. NEF overexpression decreased the expression levels of wnt/ß-catenin pathway-related proteins, while Wnt activator showed no significant effects on NEF. However, Wnt inhibitor reduced the effects of NEF overexpression on cell proliferation, migration and invasion. CONCLUSIONS: LncRNA NEF may inhibit the proliferation, migration and invasion of esophageal squamous-cell carcinoma cells by inactivating with wnt/ß-catenin pathway.

Cadherin 6 is activated by Epstein-Barr virus LMP1 to mediate EMT and metastasis as an interplay node of multiple pathways in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy, which is notorious among head-and-neck cancers with its metastatic feature. Epstein-Barr virus (EBV) infection plays a fundamental role in NPC development with the mechanism is not well understood. Here we demonstrate that EBV oncoprotein LMP1 drives EMT and metastasis of NPC by reactivating the adhesion molecule, cadherin 6 (CDH6), which normally occurs in embryogenesis with unknown role in NPC. CDH6 was found to be upregulated in LMP1-positive NPC tissues, and was identified as a target of the epithelium-specific miR-203. LMP1-activated NF-κB transcriptionally repressed the miR-203 expression by binding to the promoter region of miR-203 gene. CDH6 activation in turn induced EMT and promoted metastasis in NPC. CDH6 depletion, NF-κB inhibitor and miR-203 overexpression were able to impair the EMT effects. The miR-203 downregulation in NPC tissues was strongly associated with metastasis clinically. The CDH6 activator, Runt-related transcription factor 2 (RUNX2), was also activated by EBV in the event. For both CDH6 and RUNX2 are components at TGF-ß downstream, CDH6 became a node protein for the interplay of multiple signalings including NF-κB and TGF-ß. Therefore, the switch-on of miR-203 was important for nasopharyngeal epithelial cells to maintain normal phenotype. This study demonstrates that EBV has evolved sophisticated strategies by driving epithelial cells to obtain malignant features, particularly in NPC metastasis, providing novel biomarkers for the therapy and prognosis of EBV-associated NPC.