Phthalazinone Pyrazole Enhances the Hepatic Functions of Human Embryonic Stem Cell-Derived Hepatocyte-Like Cells via Suppression of the Epithelial-Mesenchymal Transition

4-[(5-Methyl-1H-pyrazol-3-yl)amino]-2H-phenyl-1-phthalazinone Inhibits MCPyV T Antigen Expression in Merkel Cell Carcinoma Independent of Aurora Kinase A

Merkel cell carcinoma (MCC) is frequently caused by the Merkel cell polyomavirus (MCPyV), and MCPyV-positive tumor cells depend on expression of the virus-encoded T antigens (TA). Here, we identify 4-[(5-methyl-1H-pyrazol-3-yl)amino]-2H-phenyl-1-phthalazinone (PHT)-a reported inhibitor of Aurora kinase A-as a compound inhibiting growth of MCC cells by repressing noncoding control region (NCCR)-controlled TA transcription. Surprisingly, we find that TA repression is not caused by inhibition of Aurora kinase A. However, we demonstrate that β-catenin-a transcription factor repressed by active glycogen synthase kinase 3 (GSK3)-is activated by PHT, suggesting that PHT bears a hitherto unreported inhibitory activity against GSK3, a kinase known to function in promoting TA transcription. Indeed, applying an in vitro kinase assay, we demonstrate that PHT directly targets GSK3. Finally, we demonstrate that PHT exhibits in vivo antitumor activity in an MCC xenograft mouse model, suggesting a potential use in future therapeutic settings for MCC.

Calcitriol promotes the maturation of hepatocyte-like cells derived from human pluripotent stem cells

Human hepatocyte-like cells (HLCs) derived from human pluripotent stem cells (hPSCs) represent a promising cell source for the assessment of hepatotoxicity and pharmaceutical safety testing. However, the hepatic functionality of HLCs remains significantly inferior to primary human hepatocytes. The bioactive vitamin D (VD), calcitriol, promotes the differentiation of many types of cells, and its deficiency is correlated to the severity of liver diseases. Whether calcitriol contributes to the differentiation of HLCs needs to be explored. Here, we found that the supplementation of calcitriol improved the functionalities of hPSCs-derived HLCs in P450 activities, urea production, and albumin secretion. Moreover, calcitriol also enhanced mitochondrial respiratory function with increased protein expression levels of the subunit of respiratory enzyme complexes in HLCs. Further analyses showed that the mitochondrial biogenesis regulators and mitophagy were increased by calcitriol, thus improving the mitochondrial quality. These improvements in functionality and mitochondrial condition were dependent on vitamin D receptor (VDR) because the improvements were abolished under VDR-deficient conditions. Our finding provides a cost-effective chemical process for HLC maturation to meet the demand for basic research and potential clinic applications.

miR‑217‑5p regulates myogenesis in skeletal muscle stem cells by targeting FGFR2

MicroRNA-217-5p (miR-217-5p) has been implicated in cell proliferation; however, its role in skeletal muscle stem cells (SkMSCs) remains unknown. The present study aimed to explore the roles of miR‑217‑5p in the biological characteristics of SkMSCs. SkMSCs were identified by cell surface markers using flow cytometry. The present study observed that miR‑217‑5p mimics accelerated the proliferation and suppressed the differentiation in SkMSCs. In addition, the results of the present study revealed that fibroblast growth factor receptor 2 (FGFR2) was a target of miR‑217‑5p, as miR‑217‑5p bound directly to the 3'‑untranslated region of FGFR2 mRNA, resulting in increased FGFR2 mRNA and protein levels. In addition, the present study suppressed the expression of FGFR2 in SkMSCs using a selective FGFR inhibitor AZD4547 and detected the efficiency of inhibition by reverse transcription‑quantitative PCR and western blotting. miR‑217‑5p levels were positively associated with FGFR2 expression, which was upregulated and accelerated the proliferation of SkMSCs compared with that of the miR‑NC group. Collectively, these results demonstrated that miR‑217‑5p may act as a myogenesis promoter in SkMSCs by directly targeting FGFR2 and may regulate the myogenesis of these cells.

PPTS Inhibits the TGF-β1-Induced Epithelial-Mesenchymal Transition in Human Colorectal Cancer SW480 Cells

The current study investigates the inhibitory effects of Pulsatilla pentacyclic triterpenoid saponins extract (PPTS) on epithelial-mesenchymal transition (EMT) triggered by the transforming growth factor-β1 (TGF-β1) in human colorectal cancer SW480 cell line, further illustrates the possible mechanism of PPTS inhibition of growth and invasion from the perspective of EMT, and provides new theoretical support for the treatment of tumor by Chinese medicine. The SW480 cells were treated in groups: blank control, TGF-β1 (10 ng/mL), and varying concentrations of PPTS cotreated with TGF-β1-induced (10 ng/mL) groups. CCK8 was used to detect cell viability; transwell was applied to detect invasion ability, cell migration ability was also determined, ELISA and RT-qPCR were utilized for the determination of CYP3A, CYP2C9, CYP2C19, N-cadherin, and MMP-9 expression. Flow cytometry detection was applied to detect cell cycle and apoptosis. The results obtained have shown that PPTS can significantly inhibit the invasion and migration of tumors in SW480 cells and can also block the S phase in the cell cycle but may produce cytotoxicity in higher doses. The present research work provides substantial evidence that PPTS has a significant inhibitory effect on TGF-β1-induced EMT in SW480 cells and it also promotes apoptosis.