Enhanced Sampling Molecular Dynamics Simulations Reveal Transport Mechanism of Glycoconjugate Drugs through GLUT1.

Glucose transporters GLUT1 belong to the major facilitator superfamily and are essential to human glucose uptake. The overexpression of GLUT1 in tumor cells designates it as a pivotal target for glycoconjugate anticancer drugs. However, the interaction mechanism of glycoconjugate drugs with GLUT1 remains largely unknown. Here, we employed all-atom molecular dynamics simulations, coupled to steered and umbrella sampling techniques, to examine the thermodynamics governing the transport of glucose and two glycoconjugate drugs (i.e., 6-D-glucose-conjugated methane sulfonate and 6-D-glucose chlorambucil) by GLUT1. We characterized the specific interactions between GLUT1 and substrates at different transport stages, including substrate recognition, transport, and releasing, and identified the key residues involved in these procedures. Importantly, our results described, for the first time, the free energy profiles of GLUT1-transporting glycoconjugate drugs, and demonstrated that H160 and W388 served as important gates to regulate their transport via GLUT1. These findings provide novel atomic-scale insights for understanding the transport mechanism of GLUT1, facilitating the discovery and rational design of GLUT1-targeted anticancer drugs.

Lipid metabolism-related gene signatures for predicting the prognosis of lung adenocarcinoma.

Background: Lung cancer is one of the most common epithelial malignancies worldwide, accounting for the highest number of new cases and deaths. Metabolism is the sum of chemical reactions that produce energy to keep an organism alive. Several studies have shown that glucose and lipid metabolic disorders are common phenomena related to cancer cell genesis and progression. Methods: We screened the differentially expressed genes (DEGs) of lung adenocarcinoma (LUAD) samples of The Cancer Genome Atlas (TCGA) database, the Gene Set Enrichment Analysis (GSEA), and Gene Card database metabolism-related data, the metabolism-related DEGs of LUAD, as well as the univariate Cox regression analysis genes, for identifying significant outcome-related genes. The least absolute shrinkage and gene selection operator (LASSO) analysis was performed to establish the best risk model. Results: Our study aimed to establish a lipid metabolism-related model for predicting LUAD prognosis. Furthermore, our model's prognosis prediction power was evaluated by survival analysis. This study finally identified 11 DEGs related to lipid metabolism that were significantly associated with the prognosis of lung adenocarcinoma. It provided a new idea for the treatment of high-risk lung adenocarcinoma patients. Conclusions: The constructed clinical prognosis model of lung adenocarcinoma related to lipid metabolism provides a new idea for clinical treatment of lung adenocarcinoma.

[Eleutheroside B induces apoptosis and autophagy of lung cancer cells by regulating PI3K/Akt/mTOR pathway].

This study investigated the effect of eleutheroside B on apoptosis and autophagy of lung cancer A549 and H460 cells and its molecular mechanism. MTT assay was used to detect the cytotoxicity of eleutheroside B at 5, 10, 15, 20, 25, 30, 35, 40, and 45 mmol·L~(-1) on lung cancer cells. Trypan blue exclusion assay was used to detect the effect of eleutheroside B on the survival rate of lung cancer A549 and H460 cells at different time. Colony formation assay was used to detect the effect of eleutheroside B on the proliferation of lung cancer A549 and H460 cells. AO/EB fluorescence double staining and Hoechst 33342 fluorescence staining were used to detect the effect of eleutheroside B on apoptosis of lung cancer A549 and H460 cells, and Western blot was used to detect apoptosis-related proteins to explore the apoptosis-related molecular mechanism. AO fluorescence staining and Western blot were used to detect the expression of autophagic vesicles and autophagy-related proteins P62 and LC3. The results showed that compared with the control group, eleutheroside B inhibited the growth of lung cancer A549 and H460 cells in a concentration-dependent manner. The optimal effect time of eleutheroside B on lung cancer A549 and H460 cells was 24 h, and the optimal concentrations were 28.64 and 22.16 mmol·L~(-1), respectively. Eleutheroside B could inhibit the colony formation of A549 and H460 cells. Compared with the control group, eleutheroside B could promote the formation of apoptotic bodies and induce cell apoptosis, as well as induce the expression of mitochondrial pathway-related proteins. Under the effect of eleutheroside B, the acidic autophagy vacuole in lung cancer cells increased, LC3Ⅱ expression increased, P62 protein expression decreased, and PI3K, p-Akt, and p-mTOR protein expression decreased in the PI3K/Akt/mTOR pathway. Studies have shown that eleutheroside B can inhibit the growth of lung cancer cells, reduce colony formation, induce apoptosis of lung cancer cells through mitochondrial pathway, and induce autophagy. The mechanism may be related to the PI3K/Akt/mTOR pathway.