MicroRNAs (miRNAs) are a subtype of small regulatory RNAs that are involved in numerous biological processes through small RNA-induced silencing networks. In an attempt to explore the phylogeny of miRNAs across five platyhelminths, we integrated annotated miRNAs and their full genomes. We identified conserved miRNA clusters and, in particular, miR-71/2 was conserved from planarian to parasitic flatworms and was expanded in free-living Schmidtea mediterranea. Analysis of 22 miRNA loci provided compelling evidence that most known miRNAs are conserved across platyhelminths. Meanwhile, we also observed alterations of known protein-coding genes flanking miRNA(s), such as transcriptional direction conversion and locus relocation, in around~41% of 22 known miRNA loci. Compared with Echinococcus multilocularis, the majority of these events occurred in evolution-distant Hymenolepis microstoma, Schistosoma japonicum or/and S. mediterranea. These results imply rearrangement events occurred near the known miRNA loci.
2020) MiR-616 plays oncogenic role in hepatocellular carcinoma progression through suppressing PTEN expression and activating PI3K/AKT pathway, Artificial Cells, Nanomedicine, and Biotechnology, 48:1, 728-734, ABSTRACT Aims: Given their regulatory roles in gene expression, microRNAs play an important role in tumorigenesis. The current study aimed to explore the function and the related mechanisms of miR-616 in hepatocellular carcinoma (HCC). Methods: The expression of miR-616 was detected using quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was applied to estimate the association of miR-616 with clinical characteristics of HCC patients. Cell transfection was performed by Lipofectamine V R 2000. MTT assay was used to detect cell proliferation, whereas cell motility was estimated using Transwell assay. The protein expression was detected using western blot. Results: MiR-616 was significantly up-regulated in HCC tissues and cells (p < .05 for all). Moreover, its elevated expression was positively correlated with lymph node metastasis (p ¼ .008) and TNM stage (p ¼ .012). Knockdown of miR-616 resulted in decreased cell proliferation, migration and invasion. Moreover, the inhibition of miR-616 significantly suppressed PI3K/AKT pathway. The bioinformatics analysis and luciferase reporter assay suggested that PTEN was a targeted gene of miR-616. PTEN had the capacity to reverse the oncogenic function of miR-616 in HCC. Conclusion: MiR-616 activates PI3K/AKT pathway through suppressing PTEN expression, thus promoting the progression of HCC.
ARTICLE HISTORY
Background
Researches on bone marrow mesenchymal stem cells (BMMSCs) have generated controversial results in tumor research. In the present study, we aimed to explore the functions of BMMSCs on gastric cancer and the possible mechanism in a mimicking microenvironment of the stomach.
Methods
Transwell co-cultured system was used to co-culture BMMSCs and gastric cancer SGC-7901 cells. In some experiments, androgen and its antagonist were added into the cells as required. Cell viability, cell apoptosis, mRNA and protein expressions of apoptosis- and JNK signaling- associated genes were respectively determined by performing cell counting kit-8, flow cytometry, quantitative real-time PCR and western blot.
Results
Androgen contributed to the growth of BMMSCs and SGC-7901 cells. In co-cultured system, BMMSCs not only suppressed SGC-7901 cell viability, induced cell apoptosis and promoted tumor necrosis factor (TNF)-α release, but also regulated the level of Bax/Bcl-2 and elevated the expressions of phosphorylation (p)-JNK and p53. After adding androgens, the anti-tumor effects of BMMSCs were weakened. Meanwhile, the antagonists of androgens could partially recover BMMSCs
in vitro
inhibitory effects on gastric cancer cells by activation of JNK signaling.
Conclusions
This study demonstrated the important roles of BMMSCs on the growth and apoptosis of gastric cancer cells
in vitro
. Additionally, in the mimicking microenvironment of the stomach, androgen weakened the antitumor effects of BMMSCs by limiting JNK signaling activation, suggesting that androgen antagonist may be a promising adjuvant drug to BMMSCs in gastric cancer therapy.
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