Comprehensive analysis of stearoyl-coenzyme A desaturase in prostate adenocarcinoma: insights into gene expression, immune microenvironment and tumor progression.

Prostate adenocarcinoma (PRAD) is a prevalent global malignancy which depends more on lipid metabolism for tumor progression compared to other cancer types. Although Stearoyl-coenzyme A desaturase (SCD) is documented to regulate lipid metabolism in multiple cancers, landscape analysis of its implications in PRAD are still missing at present. Here, we conducted an analysis of diverse cancer datasets revealing elevated SCD expression in the PRAD cohort at both mRNA and protein levels. Interestingly, the elevated expression was associated with SCD promoter hypermethylation and genetic alterations, notably the L134V mutation. Integration of comprehensive tumor immunological and genomic data revealed a robust positive correlation between SCD expression levels and the abundance of CD8+ T cells and macrophages. Further analyses identified significant associations between SCD expression and various immune markers in tumor microenvironment. Single-cell transcriptomic profiling unveiled differential SCD expression patterns across distinct cell types within the prostate tumor microenvironment. The Gene Ontology and Kyoto Encyclopedia of Genes and Genome analyses showed that SCD enriched pathways were primarily related to lipid biosynthesis, cholesterol biosynthesis, endoplasmic reticulum membrane functions, and various metabolic pathways. Gene Set Enrichment Analysis highlighted the involvement of elevated SCD expression in crucial cellular processes, including the cell cycle and biosynthesis of cofactors pathways. In functional studies, SCD overexpression promoted the proliferation, metastasis and invasion of prostate cancer cells, whereas downregulation inhibits these processes. This study provides comprehensive insights into the multifaceted roles of SCD in PRAD pathogenesis, underscoring its potential as both a therapeutic target and prognostic biomarker.

Enhancement of efferocytosis through biased FPR2 signaling attenuates intestinal inflammation.

Efficient clearance of dying cells (efferocytosis) is an evolutionarily conserved process for tissue homeostasis. Genetic enhancement of efferocytosis exhibits therapeutic potential for inflammation resolution and tissue repair. However, pharmacological approaches to enhance efferocytosis remain sparse due to a lack of targets for modulation. Here, we report the identification of columbamine (COL) which enhances macrophage-mediated efferocytosis and attenuates intestinal inflammation in a murine colitis model. COL enhances efferocytosis by promoting LC3-associated phagocytosis (LAP), a non-canonical form of autophagy. Transcriptome analysis and pharmacological characterization revealed that COL is a biased agonist that occupies a part of the ligand binding pocket of formyl peptide receptor 2 (FPR2), a G-protein coupled receptor involved in inflammation regulation. Genetic ablation of the Fpr2 gene or treatment with an FPR2 antagonist abolishes COL-induced efferocytosis, anti-colitis activity and LAP. Taken together, our study identifies FPR2 as a potential target for modulating LC3-associated efferocytosis to alleviate intestinal inflammation and highlights the therapeutic value of COL, a natural and biased agonist of FPR2, in the treatment of inflammatory bowel disease.

Icaritin Derivative IC2 Induces Cytoprotective Autophagy of Breast Cancer Cells via SCD1 Inhibition.

Breast cancer is one of the most prevalent malignancies and the leading cause of cancer-associated mortality in China. Icaritin (ICT), a prenyl flavonoid derived from the Epimedium Genus, has been proven to inhibit the proliferation and stemness of breast cancer cells. Our previous study demonstrated that IC2, a derivative of ICT, could induce breast cancer cell apoptosis by Stearoyl-CoA desaturase 1 (SCD1) inhibition. The present study further investigated the mechanism of the inhibitory effects of IC2 on breast cancer cells in vitro and in vivo. Our results proved that IC2 could stimulate autophagy in breast cancer cells with the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling and mitogen-activated protein kinase (MAPK) signaling. Combination treatment of the AMPK inhibitor decreased IC2-induced autophagy while it markedly enhanced IC2-induced apoptosis. In common with IC2-induced apoptosis, SCD1 overexpression or the addition of exogenous oleic acid (OA) could also alleviate IC2-induced autophagy. In vivo assays additionally demonstrated that IC2 treatment markedly inhibited tumor growth in a mouse breast cancer xenograft model. Overall, our study was the first to demonstrate that IC2 induced cytoprotective autophagy by SCD1 inhibition in breast cancer cells and that the autophagy inhibitor markedly enhanced the anticancer activity of IC2. Therefore, IC2 was a potential candidate compound in combination therapy for breast cancer.

Anti-inflammatory signaling through G protein-coupled receptors.

G protein-coupled receptors (GPCRs) play important roles in human physiology. GPCRs are involved in immunoregulation including regulation of the inflammatory response. Chemotaxis of phagocytes and lymphocytes is mediated to a great extent by the GPCRs for chemoattractants including myriads of chemokines. Accumulation and activation of phagocytes at the site of inflammation contribute to local inflammatory response. A handful of GPCRs have been found to transduce anti-inflammatory signals that promote resolution of inflammation. These GPCRs interact with selected metabolites of arachdonic acid, such as lipoxins, and of omega-3 essential fatty acids, such as resolvins and protectins. Despite mounting evidence for the in vivo functions of these anti-inflammatory and pro-resolving ligands paired with their respective GPCRs, the underlying signaling mechanisms have not been fully delineated. The present review summarizes what we have learned about these GPCRs, their structures and signaling pathways and the prospect of targeting these receptors for novel anti-inflammatory therapies.

Development of ß-amino-carbonyl compounds as androgen receptor antagonists.

AIM: Androgen receptor (AR) antagonists have proven to be useful in the early control of prostate cancer. The aim of this study was to identify and characterize a novel ß-amino-carbonyl-based androgen receptor antagonist. METHODS: Different isomers of the ß-amino-carbonyl compounds were obtained by chiral separation. The bioactivities of the isomers were evaluated by AR nuclear translocation, mammalian two-hybrid, competitive receptor binding and cell proliferation assays. The expression of genes downstream of AR was analyzed with real-time PCR. The therapeutic effects on tumor growth in vivo were observed in male SCID mice bearing LNCaP xenografts. RESULTS: Compound 21 was previously identified as an AR modulator by the high-throughput screening of a diverse compound library. In the present study, the two isomers of compound 21, termed compounds 21-1 and 21-2, were characterized as partial AR agonists in terms of androgen-induced AR nuclear translocation, prostate-specific antigen expression and cell proliferation. Further structural modifications led to the discovery of a androgen receptor antagonist (compound 6012), which blocked androgen receptor nuclear translocation, androgen-responsive gene expression and androgen-dependent LNCaP cell proliferation. Four stereoisomers of compound 6012 were isolated, and their bioactivities were assessed. The pharmacological effects of 6012, including AR binding, androgen-induced AR translocation, NH2- and COOH-terminal interaction, growth inhibition of LNCaP cells in vitro and LNCaP xenograft growth in nude mice, were mainly restricted to isomer 6012-4 (1R, 3S). CONCLUSION: Compound 6012-4 was determined to be a novel androgen receptor antagonist with prostate cancer inhibitory activities comparable to bicalutamide both in vitro and in vivo.