Biochimica et biophysica acta. General subjects最新文献

Anticancer effects of high-dose vitamin C (VC) have been evaluated on many cancer cell lines, and its efficacy in clinical trials and in combination with anticancer drugs or radiation have been reported; however, its effect on gastric cancer and its mechanisms remain unclear. In the present study, the cell growth inhibitory/lethal effects of high-dose ascorbic acid (AsA), a reduced form of VC was examined on three gastric cancer cell lines. Of these, signet ring cell carcinoma NUGC-4 cells were the most sensitive, but the effects were small and limited in normal cells. Second, high-dose AsA was effective in NUGC-4 cells, whereas dehydroascorbic acid, an oxidized form of VC, was less effective. Third, high-dose AsA showed stronger cell growth inhibitory/lethal effects on floating cells than on adherent cells, and was effective even under hypoxic microenvironment conditions. A single 1-h treatment of high-dose AsA strongly inhibited cell growth, causing apoptosis-like cell death over 72 h after treatment, triggered by hydrogen peroxide generation, actin abnormality, DNA synthesis suppression, DNA damage induction, and ATP level decrease. The effects of high-dose AsA were inhibited either by adding or chelating iron ions, but was not affected via inhibiting AsA transport. Inhibition of glutathione synthesis enhanced the anticancer effects of high-dose AsA. These results indicate that a single high-dose of AsA induces cancer cell-selective, sustained cell growth inhibition and cell death, and these effects may be regulated by iron ion and/or intracellular oxidative stress levels in human gastric signet-ring cell carcinoma-derived NUGC-4 cells.

Background: Gastric cancer remains a common malignancy with poor prognosis. While lactate metabolism is recognized as a significant factor in tumor progression, its potential as a predictive tool for treatment response remains unexplored. This study introduces a novel Lactate-Related Gene Signature (LRGS) designed to predict both survival outcomes and therapy responses in gastric cancer patients.

Methods: We comprehensively analyzed 335 lactate-related genes from 11 metabolic pathways using MSigDB, identifying 278 differentially expressed genes between gastric cancer and normal tissues. Employing the LASSO Cox regression model, we developed an innovative LRGS formula based on the expression of 16 key lactate-related genes. The impact of Solute Carrier Family 5 Member 12 (SLC5A12), a gene of particular interest, on gastric cancer cell functions was evaluated using in vitro assays and an in vivo zebrafish model.

Results: Our newly established LRGS demonstrated robust capability in stratifying gastric cancer patients by survival risk. Notably, the LRGS-low subtype showed significantly improved overall and disease-free survival rates compared to the LRGS-high subtype. A key finding was LRGS's ability to predict patient responses to both adjuvant chemotherapy and immunotherapy. Random forest analysis identified SLC5A12 as the most significant gene differentiating gastric cancer from normal tissues. Functional experiments confirmed SLC5A12's role in promoting gastric cancer cell proliferation, invasion, and migration both in vitro and in vivo.

Conclusion: The LRGS is a dependable and efficient prognostic tool for assessing the survival outcomes in individuals with gastric cancer, as well as a predictor of patient response to adjuvant chemotherapy and immunotherapy.

Obesity-induced monocyte chemoattractant protein 1 (MCP-1) production leads to the infiltration of monocytes/macrophages into white adipose tissue (WAT), which contributes to systemic insulin resistance. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists are known to reduce MCP-1 production in both humans and mice; however, the underlying mechanism in WAT remains unclear. Here, we propose a novel mechanism for the reduction in MCP-1 production in preadipocytes. The PPARγ agonist rosiglitazone (RSG) reduced MCP-1 production and secretion in response to lipopolysaccharide (LPS) in 3T3-L1 preadipocytes and mouse stromal vascular fraction-derived primary preadipocytes. Both RSG and SP600125 (a c-Jun N-terminal kinase (JNK) inhibitor) inhibited LPS-induced degradation of silent information regulator 2 homolog 1 (SIRT1), a negative regulator of MCP-1 production in 3T3-L1 preadipocytes. Furthermore, RSG inhibited LPS-induced activation of nuclear factor-κB. These effects of RSG were abolished in 3T3-L1 preadipocytes transfected with Pparg siRNA. These findings highlight a novel mechanism by which PPARγ activation inhibits JNK/SIRT1 signaling in preadipocytes and contributes to the reduction in MCP-1 production, suggesting that preadipocytes could be a potential therapeutic target for the treatment of insulin resistance.