Experimentally validated oxidative stress -associated prognostic signatures describe the immune landscape and predict the drug response and prognosis of SKCM.

Background: Skin Cutaneous Melanoma (SKCM) incidence is continually increasing, with chemotherapy and immunotherapy being among the most common cancer treatment modalities. This study aims to identify novel biomarkers for chemotherapy and immunotherapy response in SKCM and explore their association with oxidative stress. Methods: Utilizing TCGA-SKCM RNA-seq data, we employed Weighted Gene Co-expression Network Analysis (WGCNA) and Protein-Protein Interaction (PPI) networks to identify six core genes. Gene co-expression analysis and immune-related analysis were conducted, and specific markers associated with oxidative stress were identified using Gene Set Variation Analysis (GSVA). Single-cell analysis revealed the expression patterns of Oxidative Stress-Associated Genes (OSAG) in the tumor microenvironment. TIDE analysis was employed to explore the association between immune therapy response and OSAG, while CIBERSORT was used to analyze the tumor immune microenvironment. The BEST database demonstrated the impact of the Oxidative Stress signaling pathway on chemotherapy drug resistance. Immunohistochemical staining and ROC curve evaluation were performed to assess the protein expression levels of core genes in SKCM and normal samples, with survival analysis utilized to determine their diagnostic value. Results: We identified six central genes associated with SKCM metastasis, among which the expression of DSC2 and DSC3 involved in the oxidative stress pathway was closely related to immune cell infiltration. DSC2 influenced drug resistance in SKMC patients. Furthermore, downregulation of DSC2 and DSC3 expression enhanced the response of SKCM patients to immunotherapy. Conclusion: This study identified two Oxidative Stress-Associated genes as novel biomarkers for SKCM. Additionally, targeting the oxidative stress pathway may serve as a new strategy in clinical practice to enhance SKCM chemotherapy and sensitivity.

Oral Delivery of Pingyangmycin by Layer-by-Layer (LbL) Self-Assembly Polyelectrolyte-Grafted Nano Graphene Oxide.

With the increasing development in scientific technology, building a nanocarrier system for cancer drugs has become a bliss for cancer patients. To allow for the oral administration of hydrophilic drugs, a nanocarrier that was based on negatively charged graphene oxide (GO) and prepared through the Layer-by-Layer (LbL) self-assembly of poly(acrylic acid)-cysteine (PAA-cys) and poly(allylamine hydrochloride) (PAH) was established. In the present study, we demonstrated the excellent biological properties of GO, the biological adhesiveness of PAA-cys, and the protection and controlled release profiles of polyelectrolyte. Pingyangmycin (PYM) was loaded onto the nanocarrier through non-covalent interactions. In vitro drug release studies of the prepared PAA-cys-PAH-GO-PYM were pH-sensitive and showed sustained release effects for over 8 h, before they were completely expelled by gastrointestinal peristalsis. Furthermore, cell viability experiments using A549 lung adenocarcinoma cells revealed that the IC50 of PAA-cys-PAH-GO-PYM, free drug, and GO-PYM were 159.241 µM, 134.960 µM, and 129.815 µM respectively, indicating the higher retention and cytotoxicity of PYM in vitro. When comparing the oral bioavailability of PYM with free drug, in vivo pharmacokinetics studies showed a 1.03-fold and 1.74-fold increase after GO loading and double-layer polyelectrolyte coating, respectively. Thus, PAA-cys-PAH-GO was successfully developed for oral delivery of PYM as anti-cancer therapy, and may provide further insight for oral administration of GO-based nanomaterials.

Pharmacokinetics and Biodistribution of Aurantiamide and Aurantiamide Acetate in Rats after Oral Administration of Portulaca oleracea L. Extracts.

Aurantiamide and aurantiamide acetate are the main active constituents of purslane (Portulaca oleracea L.), an edible plant with various biological activities. In this study, we developed a validated UHPLC-MS/MS method to quantitate the concentrations of aurantiamide and aurantiamide acetate in the plasma and various organ tissues of rat as the basis to study their pharmacological profile and distribution in vivo. Aurantiamide and aurantiamide acetate were rapidly absorbed following oral administration, both achieving a Cmax at around 0.2 h. The extent of their metabolisms also varied among different organ tissues, resulting in about 90% reduction in concentrations 4 h after their administration, thus leaving no long-term accumulation in the tissues. This is the first study to examine the pharmacokinetic and biodistribution of aurantiamide and aurantiamide acetate in rat, and our work may serve as the first step toward the investigation of the underlying mechanisms associated with the biological activity of purslane.