MicroRNA repertoire and comparative analysis of Andrias davidianus infected with ranavirus using deep sequencing

Up-regulated miR-155 is associated with poor prognosis in childhood acute lymphoblastic leukemia and promotes cell proliferation targeting ZNF238

OBJECTIVES

Acute lymphoblastic leukemia (ALL) is one of the most common malignancies in children. Our aim was to identify a novel miRNA that can predict prognosis of childhood ALL patients and explore its potential mechanism.

METHODS

The miRNA expression profiles of childhood ALL were analyzed using GEO database and HiSeq instruments. The expression of miR-155 was examined by RT-PCR in 42 ALL patients. To investigate the role of miR-155 in ALL, four ALL cell lines (CEM-C1, Jurkat, MOLT-3 and MOLT-4) were transfected with miR-155 mimics, miR-155 inhibitors or corresponding controls. Dual-luciferase reporter system was applied to confirm the miR-155 target ZNF238. Moreover, proliferation and apoptosis were evaluated by MTT and flow cytometry.

RESULTS

Dataset GSE56489 and GSE23024 demonstrated that miR-155 was up-regulated and ZNF238 was down-regulated at diagnosis status of ALL. High miR-155 expression was associated with poor outcome. Overexpressed miR-155 promoted ALL cell proliferation and inhibited apoptosis. Dual-luciferase reporter result showed that miR-155 directly regulated ZNF238. Silencing ZNF238 promoted cell proliferation in ALL cells.

DISCUSSION

Our research indicating that miR-155 might possess potential value as a biomarker for predicting the prognosis of individuals. However, the role of ZNF238 in childhood ALL remain unknown. In the present study, we found the possible role of ZNF238 as a new tumor suppressor in ALL, which might be necessary for the antiproliferative functions of normal cells to counteract ALL formation.

CONCLUSION

Our results propose that miR-155 is in association with poor prognosis of childhood ALL. Furthermore, miR-155 could promote cell proliferation targeting ZNF238.

Post-transcriptional regulation of frog innate immunity: discovery of frog microRNAs associated with antiviral responses and ranavirus infection using a Xenopus laevis skin epithelial-like cell line

Post-transcriptional regulators such as microRNAs are emerging as conserved regulators of innate antiviral immunity in vertebrates, yet their roles in amphibian antiviral responses remain uncharacterized. We profiled changes in microRNA expressions in the Xenopus laevis skin epithelial-like cell line Xela DS2 in response to poly(I:C)—an analogue of viral double-stranded RNA and inducer of type I interferons—or frog virus 3 (FV3), an immunoevasive virus associated with amphibian mortality events. Small RNA libraries generated from untreated, poly(I:C)-treated, and FV3-infected cells were sequenced. We detected 136 known X. laevis microRNAs and discovered 133 novel X. laevis microRNAs. Sixty-five microRNAs were differentially expressed in response to poly(I:C), many of which were predicted to target regulators of antiviral pathways such as cGAS-STING, RIG-I/MDA-5, TLR signaling, and type I interferon signaling, as well as products of these pathways (NF-ĸB-induced and interferon-stimulated genes). In contrast, only 49 microRNAs were altered by FV3 infection, fewer of which were predicted to interact with antiviral pathways. Interestingly, poly(I:C) treatment or FV3 infection downregulated transcripts encoding factors of the host microRNA biogenesis pathway. Our study is the first to suggest that host microRNAs regulate innate antiviral immunity in frogs and sheds light on microRNA-mediated mechanisms of immunoevasion by FV3.

MicroRNA-150-5p and SRC kinase signaling inhibitor 1 involvement in the pathological development of gastric cancer

The current study aimed to assess the regulatory mechanism of microRNA-150-5p (miR-150-5p) in the pathogenesis of gastric cancer. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to verify the expression of miR-150-5p in gastric cancer tissues and cell lines, which was revealed to be highly expressed in each. In addition, the expression of miR-150-5p was associated with advanced gastric cancer and lymph node metastasis. The current study then hypothesized that SRC kinase signaling inhibitor 1 (SRCIN1) was the target gene of miR-150-5p, a theory that was confirmed via a dual luciferase reporter gene assay. RT-qPCR and western blotting were then performed to verify the expression of SRCIN1 in gastric cancer tissues and cell lines. The results demonstrated that SRCIN1 was lowly expressed in gastric cancer tissues and cells. To assess the effect of miR-150-5p on gastric cancer cells, experiments were conducted with BGC-823 cells transfected with a miR-150-5p inhibitor or a miR-150-5p inhibitor+SRCIN1-small interfering (si)RNA respectively. A cell counting kit-8 assay and flow cytometry were also used to assess cell viability and apoptosis, respectively. Western blotting and RT-qPCR were further used to measure the expression of specific markers of epithelial mesenchymal transition (EMT), including epithelial cell markers (E-cadherin and zona occluding-1) and interstitial cell markers (vimentin, N-cadherin and β-catenin). The results revealed that the miR-150-5p inhibitor attenuated cell viability, induced apoptosis, decreased the expression of interstitial cell markers and increased epithelial cell marker expression. However, all effects of the miR-150-5p inhibitor were reversed following SRCIN1-siRNA treatment. In summary, the current study indicated that the miR-150-5p inhibitor attenuated cell viability, induced apoptosis and inhibited gastric cancer cell EMT by targeting SRCIN1.

Discovery of MicroRNAs from Batrachuperus yenyuanensis Using Deep Sequencing and Prediction of Their Targets

MicroRNAs (miRNAs), a family of ∼22-nucleotide non-coding single-stranded RNA molecules, are considered as key post-transcriptional regulators of gene expression that regulate various biological processes in living organism. Many miRNAs have been identified in animals; however, few have been reported in Hynobiidae species. The present study is aimed to identify a full repertoire of miRNAs in Batrachuperus yenyuanensis (Yenyuan stream salamander), which would significantly increase our knowledge of miRNAs in amphibians. A small RNA library was constructed from B. yenyuanensis and sequenced using deep sequencing. As a result, 1,717,751 clean reads were obtained, representing 356 known and 80 novel miRNAs. Additionally, expression levels of eight randomly selected miRNAs in B. yenyuanensis were confirmed using the stem-loop quantitative real-time reverse transcription PCR. In addition, 13,972 targets were predicted for these identified miRNAs, although the physiological functions of many of these targets remain unknown. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that the predicted targets are involved in a variety of physiological regulatory functions in B. yenyuanensis. These results provide useful information for further research on the miRNAs involved in the growth and development of B. yenyuanensis, as well as adaptation of this species to its high-altitude habitats.