👤 Andrew K Shiau

The roles of cancer stem cells and Octamer-binding transcription factor 4 (OCT4) have been implicated in human tumorigenesis and metastasis. However, the role of OCT4 in the metastasis of non-small-cell lung cancer (NSCLC) remains undetermined, especially regarding stem cell-related pathways. Previous research has reported that dual-specificity phosphatase 6 (DUSP6), a mitogen-activated protein kinase (MAPK) phosphatase, is associated with cancer cells that display anti-apoptotic, migratory, and drug-resistance phenotypes. However, the regulation of DUSP6 in NSCLC is unclear. This study focused on the role of OCT4 in NSCLC, particularly its interaction with DUSP6. Here, we show a positive correlation between OCT4 and DUSP6 expression in NSCLC cells. Overexpression of OCT4 increased, whereas knockdown of OCT4 reduced DUSP6 expression. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays revealed that OCT4 transactivated DUSP6 expression by directly binding to the DUSP6 promoter, indicating that DUSP6 is a downstream target of OCT4. Furthermore, knockdown of DUSP6 in OCT4-overexpressing A549 human NSCLC cells decreased cell migration Show less

Elevated expression of prothymosin α (ProT) is frequently observed in cancers, but the underlying molecular mechanism remains poorly understood. Here, we report the clinical relevance of ProT expression and its correlation with lung cancer progression. We have shown that ProT was highly expressed in early-stage lung cancer, exhibiting nuclear localization; on the contrary, a loss of nuclear ProT expression was detected in late-stage tumor specimens. Furthermore, the expression of nuclear ProT impaired lung cancer cell migration, suppressed TGF-β-induced epithelial-to-mesenchymal transition (EMT)-associated transcription factor expression, and inhibited in vivo tumor metastasis. The suppressive effect of ProT was further found to trigger Smad7 acetylation-dependent deregulation of TGF-β signaling. ProT enhanced Smad7 stability by promoting its lysine acetylation, thereby competing with the binding of Smad2 to the SNAI1, TWIST1, and ZEB1 promoters. Eventually, the binding of Smad7 in the presence of ProT resulted in reduced expression of the EMT transcription factors, leading to the inhibition of TGF-β-induced EMT and tumor metastasis. Collectively, this study unravels the role of ProT in lung cancer progression and highlights the potential of nuclear ProT as an indicator for monitoring tumor development. Show less

The present report describes our efforts to convert an existing LXR agonist into an LXR antagonist using a structure-based approach. A series of benzenesulfonamides was synthesized based on structural modification of a known LXR agonist and was determined to be potent dual liver X receptor (LXR α/β) ligands. Herein we report the identification of compound 54 as the first reported LXR antagonist that is suitable for pharmacological in vivo evaluation in rodents. Show less

Structural modification of a series of dual LXRα/β agonists led to the identification of a new class of LXRβ partial agonists. An X-ray co-crystal structure shows that a representative member of this series, pyrrole 5, binds to LXRβ with a reversed orientation compared to 1. Show less