The efficacy and toxicity of antineoplastic antimetabolites: Role of gut microbiota

Analysis of serum S100A12, soluble advanced glycation end products receptor, and gut microbiome in elderly patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) ranks among the most prevalent malignancies in elderly populations, and chemotherapy resistance remains a critical clinical challenge. Emerging evidence highlights the interplay between chronic inflammation, gut microbiome dysbiosis, and CRC progression. Proinflammatory cytokines [e.g., interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α)] and mediators like S100 calcium-binding protein A12 (S100A12)/soluble receptor for advanced glycation end products (sRAGE) are implicated in tumorigenesis, while gut microbial imbalances may exacerbate inflammatory microenvironments conducive to chemotherapy resistance. However, the triad relationship between S100A12/sRAGE, gut microbiota profiles, and chemotherapy efficacy in elderly patients with CRC remains unexplored, limiting biomarker-driven therapeutic strategies.

AIM

To analyze the correlation between serum levels of S100A12, sRAGE, gut microbiome dysbiosis, and systemic inflammation in elderly patients with CRC and to assess their predictive value for chemotherapy efficacy.

METHODS

A retrospective analysis was conducted on the clinical data of 120 elderly patients with advanced-stage CRC who visited our hospital from August 2023 to May 2024. These patients were enrolled in the study group. Additionally, 120 healthy individuals undergoing routine health check-ups during the same period were selected as the control group. Serum S100A12, sRAGE, IL-6, and TNF-α levels were measured by ELISA, and fresh stool samples were collected before chemotherapy to analyze gut microbiome composition in the study group. Follow-up observations were conducted after chemotherapy. Pearson correlation analysis was used to explore the relationship between serum S100A12, sRAGE levels, and gut microbiome dysbiosis in patients with CRC. The predictive diagnostic value of pre-chemotherapy serum S100A12 and sRAGE levels for chemotherapy efficacy was assessed using receiver operating characteristic curves.

RESULTS

Pre-chemotherapy serum S100A12, sRAGE, IL-6, and TNF-α levels were significantly elevated in patients with CRC vs controls (all P < 0.05). These biomarkers progressively increased with microbiota dysbiosis severity (severe vs mild dysbiosis: S100A12: 340.26 ± 52.39 μg/L vs 302.53 ± 56.97 μg/L; sRAGE: 525.64 ± 37.32 ng/L vs 441.38 ± 48.73 ng/L, P < 0.05) and correlated strongly with IL-6 (r = 0.712) and TNF-α (r = 0.698). Post-chemotherapy, biomarker levels decreased (P < 0.05), coinciding with beneficial microbiota recovery (Bifidobacterium 176%, Lactobacillus 153%) and pathogenic taxa reduction (Escherichia coli 62%). The combined S100A12/sRAGE model predicted chemotherapy resistance with an area under the curve of 0.914 (sensitivity = 86.07%, specificity = 88.89%), outperforming individual biomarkers.

CONCLUSION

Elevated serum S100A12 and sRAGE in elderly patients with CRC reflected gut microbiome dysbiosis and systemic inflammation, driven by IL-6/TNF-α signaling. Their post-chemotherapy decline parallels microbiota restoration, supporting a microbiome-inflammation-biomarker axis. The combined biomarker model offers robust clinical utility for chemotherapy efficacy prediction and personalized therapeutic strategies.

Dual-Labeled Small Peptides in Cancer Imaging and Fluorescence-Guided Surgery: Progress and Future Perspectives

Dual-labeled compounds that combine radiolabeling and fluorescence labeling represent a significant advancement in precision oncology. Their clinical implementation enhances patient care and outcomes by leveraging the high sensitivity of radioimaging for tumor detection and taking advantage of fluorescence-based optical visualization for surgical guidance. Non-invasive radioimaging facilitates immediate identification of both primary tumors and metastases, while fluorescence imaging assists in decision-making during surgery by offering a spatial distinction between malignant and non-malignant tissue. These advancements hold promise for enhancing patient outcomes and personalization of cancer treatment. The development of dual-labeled molecular probes targeting various cancer biomarkers is crucial in addressing the heterogeneity inherent in cancer pathology and recent studies had already demonstrated the impact of dual-labeled compounds in surgical decision-making (NCT03699332, NCT03407781). This review focuses on the development and application of small dual-labeled peptides in the imaging and treatment of various cancer types. It summarizes the biomarkers targeted to date, tracing their development from initial discovery to the latest advancements in peptidomimetics. Through comprehensive analysis of recent preclinical and clinical studies, the review demonstrates the potential of these dual-labeled peptides to improve tumor detection, localization, and resection. Additionally, it highlights the evolving landscape of dual-modality imaging, emphasizing its critical role in advancing personalized and effective cancer therapy. This synthesis of current research underscores the promise of dual-labeled peptides in enhancing diagnostic accuracy and therapeutic outcomes in oncology.

How Hydroxyurea Alters the Gut Microbiome: A Longitudinal Study Involving Angolan Children with Sickle Cell Anemia

Sickle cell anemia (SCA) is an inherited hematological disorder and a serious global health problem, especially in Sub-Saharan Africa. Although hydroxyurea (HU) is the leading treatment for patients with SCA, its effects on the gut microbiome have not yet been explored. In this context, the aim of this study was to investigate this association by characterizing the gut microbiome of an Angolan SCA pediatric population before and after 6 months of HU treatment. A total of 66 stool samples were obtained and sequenced for the 16S rRNA gene (V3-V4 regions). Significant associations were observed in alpha and beta-diversity, with higher values of species richness for the children naïve for HU. We also noticed that children after HU had higher proportions of several beneficial bacteria, mostly short-chain fatty acids (SCFAs) producing species, such as Blautia luti, Roseburia inulinivorans, Eubacterium halli, Faecalibacterium, Ruminococcus, Lactobacillus rogosae, among others. In addition, before HU there was a higher abundance of Clostridium_g24, which includes C. bolteae and C. clostridioforme, both considered pathogenic. This study provides the first evidence of the HU effect on the gut microbiome and unravels several microorganisms that could be considered candidate biomarkers for disease severity and HU efficacy.