The ester derivatives obtained by C-ring modification of podophyllotoxin-induced apoptosis and inhibited proliferation in Hemangioma Endothelial Cells via downregulation of PI3K/Akt signaling pathway.

Infantile hemangioma (IH) is a common benign endothelial cell tumor in infants and young children, sometimes accompanied by potential complications, and may develop into malignant tumors. Hemangioma endothelial cells (HemECs) are one of the main components of IH. Podophyllotoxin (PPT) has been reported to have many pharmacological activities, especially anti-tumor, but its high toxicity, poor water solubility, and serious gastrointestinal side effects limit its clinical application. In this study, we have designed and synthesized 20 ester derivatives by introducing Boc-amino acids or organic acids at the C-4 position of podophyllotoxin through esterification reactions. The cytotoxicity of these compounds was evaluated on HemECs. Changes in cell proliferation and apoptotic signaling pathways were studied by DAPI staining, colony formation assay, migration assay, measurement of reactive oxygen species (ROS) levels flow cytometry, and Western blot analysis. We found that eight of the compounds were more potent than PPT. Of these, compound V-31 was the most active (IC50  = 0.079 ± 0.0049 µM). Further research indicated that compound V-31 inhibited its proliferation and migration, increased the level of ROS in cells, and induced apoptosis by downregulating p-PI3K, p-Akt, and Bcl-2, and upregulating cleaved caspase-3 and Bax. Our research provides the first insight into the application of PPT derivatives in HemECs, may provide an effective medicine for IH treatment.

The ester derivatives obtained by C-ring modification of podophyllotoxin induce apoptosis and inhibited proliferation in PC-3M cells via down-regulation of PI3K/Akt signaling pathway.

Podophyllotoxin (PPT) has been reported to have many pharmacological activities, especially its anti-tumor effects. To improve the cytotoxicity and selective effect of PPT, in this study, we have designed and synthesized 20 ester derivatives by introducing Boc-amino acids or organic acids at the C-4 position of PPT. The cytotoxicity of these compounds was evaluated with PC-3M, HemECs, A549, MCF-7 and HepG2 cells. We observed that the proliferation of PC-3M cells was inhibited by all 20 ester derivatives in the largest degree, comparing to the other cell lines. Comparing to PPT (IC50 = 234.90 ± 20.7 nM), eight derivatives had better performance in inhabiting proliferation of PC-3M cells, six of them belong to Boc-amino acid ester derivatives, and the derivative named V-05 (IC50 = 1.28 ± 0.1 nM) had the strongest inhibitation effect. Changes in cell proliferation and apoptotic signaling pathways were studied by DAPI staining, colony formation assay, migration assay, flow cytometry and western blot analysis. We found that V-05 were able to inhibit PC-3M cells proliferation and migration, and induced apoptosis by downregualting p-PI3K, p-Akt and Bcl-2, and upregulating Cleaved caspase-3 and Bax. Our research provides the first insight for the application of PPT derivatives in PC-3M cells, which may offer information to the effective medicine development for human prostate cancer treatment.

Economic downturns and nurse attachment to federal employment.

The impact of the financial crisis has been uneven-with differences across industries and occupations. Jobs linked to health care appear better insulated, with nurses specifically showing labor force gains during the recent recession. What is not known is how important public sector employment opportunities are for these national nursing trends. Observing the universe of nurses working for one of the largest (and publicly operated) health care employers, we show that worsening economic conditions lead to stronger job attachment. Relatedly, older nurses also seem more willing to delay retirement and instead transition to part-time positions during a downturn.