How Can the Microbiome Induce Carcinogenesis and Modulate Drug Resistance in Cancer Therapy?

Chemoresistance and the tumor microenvironment: the critical role of cell-cell communication

Resistance of cancer cells to anticancer drugs remains a major challenge in modern medicine. Understanding the mechanisms behind the development of chemoresistance is key to developing appropriate therapies to counteract it. Nowadays, with advances in technology, we are paying more and more attention to the role of the tumor microenvironment (TME) and intercellular interactions in this process. We also know that important elements of the TME are not only the tumor cells themselves but also other cell types, such as mesenchymal stem cells, cancer-associated fibroblasts, stromal cells, and macrophages. TME elements can communicate with each other indirectly (via cytokines, chemokines, growth factors, and extracellular vesicles [EVs]) and directly (via gap junctions, ligand-receptor pairs, cell adhesion, and tunnel nanotubes). This communication appears to be critical for the development of chemoresistance. EVs seem to be particularly interesting structures in this regard. Within these structures, lipids, proteins, and nucleic acids can be transported, acting as signaling molecules that interact with numerous biochemical pathways, thereby contributing to chemoresistance. Moreover, drug efflux pumps, which are responsible for removing drugs from cancer cells, can also be transported via EVs.

Cancer Treatment: New Drugs and Strategies

Cancer is a significant global health problem with complex treatment challenges [...].

Impact of wildfire ash on skin and gut microbiomes and survival of Rana dybowskii

Climate change and human activities escalate the frequency and intensity of wildfires, threatening amphibian habitats and survival; yet, research on these impacts remains limited. Wildfire ash alters water quality, introduces contaminants, and may disrupt microbial communities, impacting gut and skin microbiota; however, the effects on gut and skin microbiota remain unclear. Rana dybowskii were exposed to five concentrations (0 g L-1, 1.25 g L-1, 2.5 g L-1, 5 g L-1, and 10 g L-1) of aqueous extracts of wildfire ashes (AEAs) for 30 days to assess AEAs' metal content, survival, and microbiota diversity via Illumina sequencing. Our results showed that the major elements in ash were Ca > K > Mg > Al > Fe > Na > Mn, while in AEA they were K > Ca > Na > Mg > As > Al > Cu. A significant decrease in amphibian survival rates with increased AEA concentration was shown. The beta diversity analysis revealed distinct shifts in microbiota composition. Notably, bacterial genera associated with potential health risks showed increased abundance in skin microbiota, emphasising the potential for ash exposure to affect amphibian health. Functional prediction analyses revealed significant shifts in metabolic pathways related to health and disease, indicating that wildfire ash exposure may influence amphibian health through changes in microbial functions. This study highlights the urgent need for strategies to mitigate wildfire ash impacts on amphibians, as it significantly alters microbiota and affects their survival and health.

Human and animal intestinal commensals and probiotics vs modern challenges of biosafety: problems and prospects

The appearance of an array of data on the study of the intestinal microbiota in Metazoa has significantly expanded our understanding of the role of commensals in the control of a wide range of physiological functions in higher organisms in norm and pathology. In the intestine, where the microbial load significantly exceeds the number of microorganisms of other ecosystems, the components of the intestinal microbiota are a constant source of stimuli that induce activation of the host immune system. The introduction into practice of biomedical research of innovative high-resolution methods, including   multi-omics technologies, has brought data that change our understanding of intestinal commensals, including probiotics with GRAS status, widely used in medicine, agriculture and biotechnology. The ability of these bacteria to induce negative processes in the host body that are beneficial for bacterial proliferation and expansion revealed a clear lack of our knowledge about the logic of their life and the mechanisms of interaction with eukaryotic cells. This determines the urgent need for comprehensive research of probiotics and the development of standardization of their safety assessment. Apriori's confidence in the exceptional benefit of the bacteria widely used in medicine, agriculture and biotechnology has determined the seriously omission in our control system today - the lack of standardization of studies for the safety assessment of bacteria with GRAS status . The moment has come when it became clear that this gap should be promptly filled and that only exact understanding the molecular base of interacting the microbes with eukaryotic cells can provide the foundation for effective practical developments in controlling the evolution of bacterial virulence and probiotic safety strategy, as well as the competent use of genetic technologies for monitoring the environment and managing infectious processes, thus avoiding the dramatic consequences of large-scale interventions in the micro and macro worlds.

Microbial Therapy and Breast Cancer Management: Exploring Mechanisms, Clinical Efficacy, and Integration within the One Health Approach

This comprehensive review elucidates the profound relationship between the human microbiome and breast cancer management. Recent findings highlight the significance of microbial alterations in tissue, such as the gut and the breast, and their role in influencing the breast cancer risk, development, progression, and treatment outcomes. We delve into how the gut microbiome can modulate systemic inflammatory responses and estrogen levels, thereby impacting cancer initiation and therapeutic drug efficacy. Furthermore, we explore the unique microbial diversity within breast tissue, indicating potential imbalances brought about by cancer and highlighting specific microbes as promising therapeutic targets. Emphasizing a holistic One Health approach, this review underscores the importance of integrating insights from human, animal, and environmental health to gain a deeper understanding of the complex microbe-cancer interplay. As the field advances, the strategic manipulation of the microbiome and its metabolites presents innovative prospects for the enhancement of cancer diagnostics and therapeutics. However, rigorous clinical trials remain essential to confirm the potential of microbiota-based interventions in breast cancer management.