Δ2-Troglitazone promotes cytostatic rather than pro-apoptotic effects in breast cancer cells cultured in high serum conditions

Prediction and verification of the prognostic biomarker SLC2A2 and its association with immune infiltration in gastric cancer

Gastric cancer (GC) is the fifth most common cause of cancer-associated deaths; however, its treatment options are limited. Despite clinical improvements, chemotherapy resistance and metastasis are major challenges in improving the prognosis and quality of life of patients with GC. Therefore, effective prognostic biomarkers and targets associated with immunological interventions need to be identified. Solute carrier family 2 member 2 (SLC2A2) may serve a role in tumor development and invasion. The present study aimed to evaluate SLC2A2 as a prospective prognostic marker and chemotherapeutic target for GC. SLC2A2 expression in several types of cancer and GC was analyzed using online databases, and the effects of SLC2A2 expression on survival prognosis in GC were investigated. Clinicopathological parameters were examined to explore the association between SLC2A2 expression and overall survival (OS). Associations between SLC2A2 expression and immune infiltration, immune checkpoints and IC50 were estimated using quantification of the tumor immune contexture from human RNA-seq data, the Tumor Immune Estimation Resource 2.0 database and the Genomics of Drug Sensitivity in Cancer database. Differential SLC2A2 expression and the predictive value were validated using the Human Protein Atlas, Gene Expression Omnibus, immunohistochemistry and reverse transcription-quantitative PCR. SLC2A2 expression was downregulated in most types of tumor but upregulated in GC. Functional enrichment analysis revealed an association between SLC2A2 expression and lipid metabolism and the tumor immune microenvironment. According to Gene Ontology term functional enrichment analysis, SLC2A2-related differentially expressed genes were enriched predominantly in 'chylomicron assembly', 'plasma lipoprotein particle assembly', 'high-density lipoprotein particle', 'chylomicron', 'triglyceride-rich plasma lipoprotein particle', 'very-low-density lipoprotein particle'. 'intermembrane lipid transfer activity', 'lipoprotein particle receptor binding', 'cholesterol transporter activity' and 'intermembrane cholesterol transfer activity'. In addition, 'cholesterol metabolism', and 'fat digestion and absorption' were significantly enriched in the Kyoto Encyclopedia of Genes and Genomes pathway analysis. Patients with GC with high SLC2A2 expression had higher levels of neutrophil and M2 macrophage infiltration and a significant inverse correlation was observed between SLC2A2 expression and MYC targets, tumor mutation burden, microsatellite instability and immune checkpoints. Furthermore, patients with high SLC2A2 expression had worse prognosis, including OS, disease-specific survival and progression-free interval. Multivariate regression analysis demonstrated that SLC2A2 could independently prognosticate GC and the nomogram model showed favorable performance for survival prediction. SLC2A2 may be a prospective prognostic marker for GC. The prediction model may improve the prognosis of patients with GC in clinical practice, and SLC2A2 may serve as a novel therapeutic target to provide immunotherapy plans for GC.

New desulfured troglitazone derivatives: Improved synthesis and biological evaluation

Breast cancer is a major medical threat which cannot be sufficiently addressed by current therapies because of spontaneous or acquired treatment resistance. Besides, triple-negative breast cancer (TNBC) tumors do not respond to targeted therapies, thus new therapeutic strategies are needed. In this context, we designed and prepared new desulfured troglitazone (TGZ)-derived molecules and evaluated them in vitro for their anti-proliferative activity, with a special focus on triple-negative breast cancer cell lines. Optimization of the synthetic strategies and deracemization of the lead compound were performed to give highly active compound 10 with low-micromolar potency. Further studies revealed that this compound triggers apoptosis rather than cell cycle arrest as observed with TGZ.

Icariin attenuates titanium particle-induced inhibition of osteogenic differentiation and matrix mineralization via miR-21-5p

Inhibition of bone regeneration by wear debris is the main cause of peri-prosthetic osteolysis. Here, we investigated the effect of icariin on cell proliferation, apoptosis, osteogenic differentiation and matrix mineralization of osteoblasts in an in vitro model of titanium (Ti) particle-induced osteolysis. In the present study, MC3T3-E1 cells were pretreated with 10^-8  M icariin for 4 h and then incubated with Ti particles (0.1 mg/mL). The results showed that Ti particles inhibited cell proliferation and promoted cell apoptosis of MC3T3-E1 cells, whereas icariin pretreatment blocked the effect of Ti particles. In addition, we found that icariin stimulation alone increased ALP activity, accelerated matrix mineralization and upregulated the levels of bone morphogenetic protein 2 (BMP2), Runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and miR-21-5p; whereas, Ti particles alone exerted the opposite effects. Icariin partly reversed the effect of Ti particles on cell differentiation and mineralization. Twenty hours after transfection with antagomiR-21-5p or antagomiR-NC, the cells were pretreated with icariin for 4 h and then incubated with Ti particles. Further studies showed that partial knockdown of miR-21-5p abolished the promotion effect of icariin on osteoblast differentiation and matrix mineralization in Ti particle-stimulated MC3T3-E1 cells. In conclusion, miR-21-5p may be a potential pro-osteogenesis regulator and icariin may protect against Ti particle-induced inhibition of osteogenic differentiation and mineralization through upregulation of miR-21-5p.