Biochemical and biophysical research communications
-
Biochem. Biophys. Res. Commun. · May 2016
DHX33 expression is increased in hepatocellular carcinoma and indicates poor prognosis.
DEAH-box helicase 33 (DHX33) has been implicated in ribosome biogenesis, mRNA translation and inflammation. However, the role of DHX33 in human cancer is rarely studied. Here, we showed that DHX33 expression was significantly increased in hepatocellular carcinoma (HCC), compared with the adjacent nontumorous tissues. ⋯ The prognostic value of DHX33 was further confirmed by stratified survival analysis. Multivariate analysis revealed DHX33 as an independent prognostic factor for poor overall survival (Hazard Ratio = 1.772, 95% confident interval: 1.451-2.165, P < 0.0001). Our data therefore suggest DHX33 is overexpressed in HCC and serves as a promising prognostic biomarker for this deadly disease.
-
Biochem. Biophys. Res. Commun. · May 2016
PEK-1 is crucial for hormesis induced by inhibition of the IRE-1/XBP-1 pathway in the Caenorhabditis elegans mev-1 mutant.
The accumulation of unfolded proteins in the endoplasmic reticulum (ER) causes an imbalance of proteostasis and is related to many pathological conditions. In answer to this ER stress cells activate a network of three integrated signaling pathways consolidated as the unfolded protein response of the ER (UPR(ER)), which is also present in the stress-sensitive Caenorhabditis elegans mutant mev-1. ⋯ Moreover, ire-1/xbp-1 double-RNAi significantly increased chymotrypsin-like proteasomal activity, which was completely blocked under additional RNAi versus pek-1. In conclusion, we identified PEK-1 as a mediator of hormesis in the mev-1 mutant of C. elegans which is induced by simultaneous inhibition of XBP-1 and its splicing activator IRE-1 and mediated through activation of the proteasome.
-
Biochem. Biophys. Res. Commun. · Apr 2016
Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells.
Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. ⋯ In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC.
-
Biochem. Biophys. Res. Commun. · Apr 2016
A novel selective inhibitor to thrombin-induced platelet aggregation purified from the leech Whitmania pigra.
The dried whole body of the leech Whitmania pigra, a well-known traditional Chinese medicine, has been widely used to treat thrombus diseases for thousands of years. However, its bioactive constituents were reported rarely. The aim of our study was to investigate antithrombotic components of it. ⋯ Taken together, we found a novel peptide from leech bodies, and this peptide showed antiplatelet aggregation and antithrombotic effects.
-
Biochem. Biophys. Res. Commun. · Apr 2016
Prolyl hydroxylase 3 overexpression accelerates the progression of atherosclerosis in ApoE-/- mice.
PHD3 belongs to the family of 2-oxoglutarate and iron-dependent dioxygenases and is a critical regulator of HIF-1α. Its expression is increased in cardiovascular diseases such as cardiomyopathy, myocardial ischemia-reperfusion injury, and congestive heart failure. However, the association between PHD3 and atherosclerosis has not been clearly elucidated. ⋯ PHD3 over-expression is associated with activation of ERK1/2 and JNK phosphorylation of MAPK signaling pathway. PHD3 inhibition decreased the apoptosis of HUVECs treated with ox-LDL (50 μg/ml). Our study suggests that PHD3 is not only a regulator of HIF-1α but also an active participant in atherogenesis.