Search

Cancer: vitamin A derivative prevents salivary gland tumors spreading Treatment of salivary gland tumors with a metabolite of vitamin A could help prevent rare cancer from spreading to the lungs. A team led by Xiao-hong Chen and Lu Kong from Capital Medical University in Beijing, China, performed extensive molecular profiling on primary and metastatic tumor cells taken from two patients with advanced salivary gland cancer. Even though these patients’ cancers did not harbor either of two common mutations that are hallmarks of the disease, both of which drive tumor proliferation and spread, the cells did show signs of altered gene expression and faulty molecular signaling consistent with these same mutational profiles. The abnormal signaling could be overcome by treatment with retinoic acid, a derivative of vitamin A that, when given to mouse models of cancer, reduced the development of lung metastases.

The roles of lamin A/C in adipocyte differentiation and skeletal muscle lipid metabolism are associated with familial partial lipodystrophy of Dunnigan (FPLD). We confirmed that LMNA knockdown (KD) in mouse adipose-derived mesenchymal stem cells (AD-MSCs) prevented adipocyte maturation. Importantly, in in vitro experiments, we discovered a significant increase in phosphorylated lamin A/C levels at serine 22 or 392 sites (pLamin A/C-S22/392) accompanying increased lipid synthesis in a liver cell line (7701 cells) and two hepatocellular carcinoma (HCC) cell lines (HepG2 and MHCC97-H cells). Moreover, HCC cells did not survive after LMNA knockout (KO) or even KD. Evidently, the functions of lamin A/C differ between the liver and adipose tissue. To date, the mechanism of hepatocyte lipid metabolism mediated by nuclear lamin A/C remains unclear. Our in-depth study aimed to identify the molecular connection between lamin A/C and pLamin A/C, hepatic lipid metabolism and liver cancer. Gain- and loss-of-function experiments were performed to investigate functional changes and the related molecular pathways in 7701 cells. Adenosine 5’ monophosphate-activated protein kinase α (AMPKα) was activated when abnormalities in functional lamin A/C were observed following lamin A/C depletion or farnesyltransferase inhibitor (FTI) treatment. Active AMPKα directly phosphorylated acetyl-CoA-carboxylase 1 (ACC1) and subsequently inhibited lipid synthesis but induced glycolysis in both HCC cells and normal cells. According to the mass spectrometry analysis, lamin A/C potentially regulated AMPKα activation through its chaperone proteins, ATPase or ADP/ATP transporter 2. Lonafarnib (an FTI) combined with low-glucose conditions significantly decreased the proliferation of the two HCC cell lines more efficiently than lonafarnib alone by inhibiting glycolysis or the maturation of prelamin A.

Clean and O-(2 2 × 2 ) R45° Cu(100) surfaces were prepared to study the impact of surface oxygen on the activation of methane dissociation. Auger electron spectroscopy, low energy electron diffraction, infrared reflection absorption spectroscopy, scanning tunneling microscope, and a quadrupole mass-spectrometer for temperature programmed desorption were used to explore the behavior of CH4 on the two surfaces. The dissociative adsorption of CH4 was observed on oxygen-pre-covered Cu(100) but not on the clean surface indicating surface oxygen promotes the dissociation of the C–H bond. This study can be a reference for the conversion of methane into other high-value-added products with high efficiency and low energy consumption. [ABSTRACT FROM AUTHOR]

Accurately controlling the product selectivity in syngas conversion, especially increasing the olefin selectivity while minimizing C1 byproducts, remains a significant challenge. Epsilon Fe2C is deemed a promising candidate catalyst due to its inherently low CO2 selectivity, but its use is hindered by its poor high-temperature stability. Herein, we report the successful synthesis of highly stable ε-Fe2C through a N-induced strategy utilizing pyrolysis of Prussian blue analogs (PBAs). This catalyst, with precisely controlled Mn promoter, not only achieved an olefin selectivity of up to 70.2% but also minimized the selectivity of C1 byproducts to 19.0%, including 11.9% CO2 and 7.1% CH4. The superior performance of our ε-Fe2C-xMn catalysts, particularly in minimizing CO2 formation, is largely attributed to the interface of dispersed MnO cluster and ε-Fe2C, which crucially limits CO to CO2 conversion. Here, we enhance the carbon efficiency and economic viability of the olefin production process while maintaining high catalytic activity. Epsilon Fe2C is considered a promising catalyst for syngas conversion due to its inherently low CO2 selectivity, but its application is limited by poor high-temperature stability. Here the authors present a successful method for synthesizing highly stable ε-Fe2C using a nitrogen-induced strategy through the pyrolysis of Prussian blue analogs. [ABSTRACT FROM AUTHOR]