IRAK1 Augments Cancer Stemness and Drug Resistance via the AP-1/AKR1B10 Signaling Cascade in Hepatocellular Carcinoma.

Frequent relapse and drug resistance in patients with hepatocellular carcinoma (HCC) can be attributed to the existence of tumor-initiating cells (TIC) within the tumor bulk. Therefore, targeting liver TICs may improve the prognosis of these patients. From transcriptome sequencing of 16 pairs of clinical HCC samples, we report that interleukin-1 receptor-associated kinase 1 (IRAK1) in the TLR/IRAK pathway is significantly upregulated in HCC. IRAK1 overexpression in HCC was further confirmed at the mRNA and protein levels and correlated with advanced tumor stages and poor patient survival. Interestingly, IRAK4, an upstream regulator of IRAK1, was also consistently upregulated. IRAK1 regulated liver TIC properties, including self-renewal, tumorigenicity, and liver TIC marker expression. IRAK1 inhibition sensitized HCC cells to doxorubicin and sorafenib treatment in vitro via suppression of the apoptotic cascade. Pharmacological inhibition of IRAK1 with a specific IRAK1/4 kinase inhibitor consistently suppressed liver TIC populations. We identified aldo-keto reductase family 1 member 10 (AKR1B10) as a novel downstream target of IRAK1, which was found to be overexpressed in HCC and significantly correlated with IRAK1 expression. Knockdown of AKR1B10 negated IRAK1-induced TIC functions via modulation of the AP-1 complex. Inhibition of IRAK1/4 inhibitor in combination with sorafenib synergistically suppressed tumor growth in an HCC xenograft model. In conclusion, targeting the IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway may be a potential therapeutic strategy against HCC.Significance: IRAK4/IRAK1/AP-1/AKR1B10 signaling pathway regulates cancer stemness and drug resistance and may be a novel therapeutic target in HCC. Cancer Res; 78(9); 2332-42. ©2018 AACR.

Badiranji Buya Keli, a Traditional Uyghur Medicine, Induces Vasodilation in Rat Artery: Signaling Mediated by Nitric Oxide Production in Endothelial Cells.

Badiranji Buya Keli (BBK) is a traditional Uyghur medicine derived from Dracocephalum Moldavica Herba (DMH, the aerial part of Dracocephalum moldavica L.). BBK has been widely used in treating cardiovascular and cerebrovascular diseases. Here, the quality control of BBK was established by using HPLC analysis of rosmarinic acid and tilianin. After chemical standardization, the biological effects of BBK was tested. First, BBK inhibited platelet aggregation of rabbit plasma. Second, BBK induced vasodilation in rat aortic ring, and this effect was partially mediated by nitric oxide (NO) production in endothelial cells. Third, BBK induced NO production in cultured human umbilical vein endothelial cells (HUVECs). In HUVECs, the phosphorylation of endothelial NO synthase (eNOS) was markedly increased after application of BBK. Pre-treatment with the eNOS blocker N(ω) -nitro-l-arginine methyl ester hydrochloride could abolish BBK-induced NO production and eNOS phosphorylation. Taken together, these results suggest that BBK could exert beneficial effects in cardiovascular system, which may provide parts of molecular explanation to account for its traditional usage in Uyghur medicine.

Reduced Expression of P2Y2 Receptor and Acetylcholinesterase at Neuromuscular Junction of P2Y1 Receptor Knock-out Mice.

ATP is co-stored and co-released with acetylcholine (ACh) at the pre-synaptic vesicles in vertebrate neuromuscular junction (nmj). Several lines of studies demonstrated that binding of ATP to its corresponding P2Y1 and P2Y2 receptors in the muscle regulated post-synaptic gene expressions. To further support the notion that P2Y receptors are playing indispensable role in formation of post-synaptic specifications at the nmj, the knock-out mice of P2Y1 receptor (P2Y1R (-/-)) were employed here for analyses. In P2Y1R (-/-) mice, the expression of P2Y2 receptor in muscle was reduced by over 50 %, as compared to P2Y1R (+/+) mice. In parallel, the expression of acetylcholinesterase (AChE) in muscle was markedly decreased. In the analysis of the expression of anchoring subunits of AChE in P2Y1R (-/-) mice, the proline-rich membrane anchor (PRiMA) subunit was reduced by 60 %; while the collagen tail (ColQ) subunit was reduced by 50 %. AChE molecular forms in the muscle were not changed, except the amount of enzyme was reduced. Immuno-staining of P2Y1R (-/-) mice nmj, both AChE and AChR were still co-localized at the nmj, and the staining was diminished. Taken together our data demonstrated that P2Y1 receptor regulated the nmj gene expression.