MicroRNA-34a is a tumor suppressor in choriocarcinoma via regulation of Delta-like1

Abstract

BackgroundChoriocarcinoma is a gestational trophoblastic tumor which causes high mortality if left untreated. MicroRNAs (miRNAs) are small non protein-coding RNAs which inhibit target gene expression. The role of miRNAs in choriocarcinoma, however, is not well understood. In this study, we examined the effect of miR-34a in choriocarcinoma.MethodsMiR-34a was either inhibited or ectopically expressed transiently in two choriocarcinoma cell lines (BeWo and JEG-3) respectively. Its actions on cell invasion, proliferation and colony formation at low cell density were examined. The miR-34a putative target Notch ligand Delta-like 1 (DLL1) was identified by adoption of different approaches including: in-silico analysis, functional luciferase assay and western blotting. Real-time quantitative polymerase chain reaction was used to quantify changes in the expression of matrix proteinase in the treated cells. To nullify the effect of miR-34a ectopic expression, we activated Notch signaling through force-expression of the Notch intracellular domain in the miR-34a force-expressed cells. In addition, we studied the importance of DLL1 in BeWo cell invasion through ligand stimulation and antibody inhibition. Furthermore, the induction in tumor formation of miR-34a-inhibited BeWo cells in SCID mice was investigated.ResultsTransient miR-34a force-expression significantly suppressed cell proliferation and invasion in BeWo and JEG-3 cells. In silicon miRNA target prediction, luciferase functional assays and Western blotting analysis demonstrated that miR-34a regulated DLL1 expression in both cell lines. Although force-expression of miR-34a suppressed the expression of DLL1 and NOTCH1, the extent of suppression was higher in DLL1 than NOTCH1 in both cell lines. MiR-34a-mediated DLL1 suppression led to reduced matrix metallopeptidase 9 and urokinase-type plasminogen activator expression. The effect of miR-34a on cell invasion was partially nullified by Notch signaling activation. DLL1 ligand stimulated while anti-DLL1 antibody treatment suppressed cell invasion. Mice inoculated with BeWo cells transfected with miR-34a inhibitor had significantly larger xenografts and stronger DLL1 expression than those with cells transfected with the control inhibitor.ConclusionsMiR-34a reduced cell proliferation and invasiveness, at least, partially through its inhibitory effect on DLL1.

Influence of Delta-Like 1 on chemotherapeutic sensitivity of small cell lung cancer

“…In addition, forced expression of miR-34a suppressed the invasiveness of HeLa and JAR cells, which was attributed to the regulation of expression of urokinase plasminogen activator through Notch (Pang et al, 2010). More recently, they observed that miR-34a reduced cell proliferation and invasiveness, at least, partially through its inhibitory effect on DLL1 in choriocarcinoma (Pang et al, 2013). Our pilot study with microarray revealed that the DLL1 expression in resistant H69AR cells was significantly lower than that in sensitive H69 cells.…”

Rapamycin can restore the negative regulatory function of transforming growth factor beta 1 in high grade lymphomas

“…Data about elevated mTORC1-activation in numerous solid tumours and lymphomas are increasing. Our experimental and in vivo xenograft results suggest that the addition of rapalogues to treatment protocols could be beneficial not only in mantle cell lymphomas (MCLs) but also in other lymphomas with high mTORC1 activity -such as Hodgkin lymphomas, non-germinal center type diffuse large B-cell lymphomas and acute lymphoblastic leukemias [24,[37][38][39][40].…”

“…mTOR activity related phosphorylated proteins (p-mTOR, p-p70S6K, p-4EBP1 and p-S6) were detected in biopsies of Burkitt-lymphoma patients [24] and in HT58 lymphoma xenografts, which suggests that enhanced mTOR signalling activity is present in vivo (Supplemented Figure), which may serve as a potential therapeutic target. To prove the in vivo relevance of our observations, mice with HT58 lymphoma xenografts were treated with low dose Rapamune.…”

Effects of sorafenib on lung metastasis in rats with hepatocellular carcinoma: the role of microRNAs

“…Analytical proteins included P53 [6,7] and CMYC [8,9] (oncogene related); Ki67 (proliferation related); BCL-2 [10,11] (apotosis related); NM23 [12] (metastasis related); E-calrentin and β-catenin (adhesion related); CDK4 [13] and Cyclin1 [14] (cell cycle related); VEGR (angiogenesis related), GST [15], COX-2 [16], MDM2 [17], and TS (drug related); and EBV [18] (virus related).…”