Uroacitides

Cell differentiation agent II (CDA‑II) is a DNA methyltransferase inhibitor isolated from healthy human urine. In the present study, the antitumor activity of CDA‑II on human multiple myeloma (MM) cell lines via the mitochondrial pathway was first revealed. The human MM cell lines were exposed to CDA‑II. Cytotoxicity, caspase activation, apoptosis and the effects on the mitochondrial pathway were assessed. CDA‑Ⅱ was capable of decreasing the depolarized mitochondrial membranes and activating caspase‑3 and ‑9 and poly (ADP‑ribose) polymerase in MM cells treated with CDA‑II. CDA‑II induced caspase‑dependent cell death accompanied by a significant decrease in X-linked inhibitor of apoptosis protein (XIAP), survivin and Mcl‑1 levels. The caspase‑3 inhibitor, Z‑DEVD‑FMK, inhibited CDA‑II‑induced apoptosis. CDA‑II potently increased the Bax levels, decreased the Bcl‑2/Bax ratio and decreased the expression of the downstream targets of NF‑κB. In conclusion, the results of the present study demonstrated that CDA‑II treatment leads to the inhibition of p65 nuclear localization and potently induces caspase‑dependent apoptosis in MM cells mediated through the mitochondrial pathway at low nanomolar concentrations. These results indicate that CDA‑II is a novel inhibitor of NF‑κB activity, with notable antimyeloma efficacy. This study provides a rationale for the clinical investigation of CDA‑Ⅱ in human MM.

The aberrant expression of cyclin-dependent kinase-4 (CDK4) has previously been observed in human brain glioma. Furthermore, it is observed that up-regulation of CDK4 is associated with therapy resistance and relapse. However, the mechanisms behind these phenomena remain unclear. Here, we demonstrated that elevated CDK4 expression is correlated with poor prognosis in glioma after radiotherapy and that CDK4 knockdown conferred radiosensitivity in glioma cell lines. CDK4 was identified as potential downstream target of miR-124 through bioinformatics analysis and dual-firefly luciferase reporter assay. Furthermore, restoration of miR-124 could confer radiosensitivity. Cell differentiation agent-2 (CDA-2) mimicked the effect of miR-124 restoration and CDK4 knockdown, and sensitized xenografts to radiation in an animal model. Our findings demonstrated for the first time that CDK4 was a downstream target of miR-124 and that CDA-2 could radiosensitize Glioblastoma multiforme cells through the MiR-124-CDK4 axis.