Loss of exosomal miR-200b-3p from hypoxia cancer-associated fibroblasts promotes tumorigenesis and reduces sensitivity to 5-Flourouracil in colorectal cancer via upregulation of ZEB1 and E2F3

Exosomal microRNAs: impact on cancer detection, treatment, and monitoring

Exosomes, measuring between 30 and 150 nm in diameter, are small vesicles enclosed by a lipid bilayer membrane. They are released by various cells in the body and carry a diverse payload of molecules, including proteins, lipids, mRNA, and different RNA species such as long non-coding RNA, circular RNA, and microRNA (miRNA). With lengths of approximately 19-22 nucleotides, miRNAs constitute the predominant cargo in exosomes and serve as crucial regulators of protein biosynthesis. In cancer detection, exosomal miRNAs show promise as non-invasive biomarkers due to their stability and presence in various bodily fluids, aiding in early detection and precise diagnosis with specific miRNA signatures linked to different cancer types. Moreover, exosomal miRNAs influence treatment outcomes by affecting cellular processes like cell growth, cell death, and drug resistance, thereby impacting response to therapy. Additionally, they serve as indicators of disease progression and treatment response, providing insights that can guide treatment decisions and improve patient care. Through longitudinal studies, changes in exosomal miRNA profiles have been observed to correlate with disease progression, metastasis, and response to therapy, highlighting their potential for real-time monitoring of tumor dynamics and treatment efficacy. Understanding the intricate roles of exosomal miRNAs in cancer biology offers opportunities for developing innovative diagnostic tools and therapeutic strategies tailored to individual patients, ultimately advancing precision medicine approaches and improving outcomes for cancer patients. This review aims to provide an understanding of the role of exosomal miRNAs in cancer detection, treatment, and monitoring, shedding light on their potential for revolutionising oncology practices and patient care.

Function and mechanism of exosomes derived from different cells as communication mediators in colorectal cancer metastasis

Colorectal cancer (CRC) ranks as the second leading cause of cancer-related mortality, with metastasis being the primary determinant of poor prognosis in patients. Investigating the molecular mechanisms underlying CRC metastasis is currently a prominent and challenging area of research. Exosomes, as crucial intercellular communication mediators, facilitate the transfer of metabolic and genetic information from cells of origin to recipient cells. Their roles in mediating information exchange between CRC cells and immune cells, fibroblasts, and other cell types are pivotal in reshaping the tumor microenvironment, regulating key biological processes such as invasion, migration, and formation of pre-metastatic niche. This article comprehensively examines the communication function and mechanism of exosomes derived from different cells in cancer metastasis, while also presenting an outlook on current research advancements and future application prospects. The aim is to offer a distinctive perspective that contributes to accurate diagnosis and rational treatment strategies for CRC.

The FOXO1/G6PC axis promotes gastric cancer progression and mediates 5-fluorouracil resistance by targeting the PI3K/AKT/mTOR signaling pathway

Gastric cancer (GC) is a prevalent malignancy of the digestive system. Distant metastasis and chemotherapy resistance are the crucial obstacles to prognosis in GC. Recent research has discovered that the glucose-6-phosphatase catalytic subunit (G6PC) plays an important role in tumor malignant development. However, little evidence has highlighted its role in GC. Herein, through a comprehensive analysis including profiling of tissue samples and functional validation in vivo and in vitro, we identify G6PC as a crucial factor in GC tumorigenesis. Importantly, we found that the FOXO1/G6PC axis could accelerate GC cell proliferation, metastasis, and 5-Fluorouracil (5-FU) resistance by targeting the PI3K/AKT/mTOR signaling pathway, implicating that as a prospective therapeutic approach in GC.

Extracellular vesicles and cancer stemness in hepatocellular carcinoma - is there a link?

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy, with high recurrence rates and notorious resistance to conventional chemotherapy. Cancer stemness refers to the stem-cell-like phenotype of cancer cells and has been recognized to play important roles in different aspects of hepatocarcinogenesis. Small extracellular vesicles (sEVs) are small membranous particles secreted by cells that can transfer bioactive molecules, such as nucleic acids, proteins, lipids, and metabolites, to neighboring or distant cells. Recent studies have highlighted the role of sEVs in modulating different aspects of the cancer stemness properties of HCC. Furthermore, sEVs derived from diverse cellular sources, such as cancer cells, stromal cells, and immune cells, contribute to the maintenance of the cancer stemness phenotype in HCC. Through cargo transfer, specific signaling pathways are activated within the recipient cells, thus promoting the stemness properties. Additionally, sEVs can govern the secretion of growth factors from non-cancer cells to further maintain their stemness features. Clinically, plasma sEVs may hold promise as potential biomarkers for HCC diagnosis and treatment prediction. Understanding the underlying mechanisms by which sEVs promote cancer stemness in HCC is crucial, as targeting sEV-mediated communication may offer novel strategies in treatment and improve patient outcome.

Dynamic interactions in the tumor niche: how the cross-talk between CAFs and the tumor microenvironment impacts resistance to therapy

The tumor microenvironment (TME) is a complex ecosystem of cells, signaling molecules, and extracellular matrix components that profoundly influence cancer progression. Among the key players in the TME, cancer-associated fibroblasts (CAFs) have gained increasing attention for their diverse and influential roles. CAFs are activated fibroblasts found abundantly within the TME of various cancer types. CAFs contribute significantly to tumor progression by promoting angiogenesis, remodeling the extracellular matrix, and modulating immune cell infiltration. In order to influence the microenvironment, CAFs engage in cross-talk with immune cells, cancer cells, and other stromal components through paracrine signaling and direct cell-cell interactions. This cross-talk can result in immunosuppression, tumor cell proliferation, and epithelial-mesenchymal transition, contributing to disease progression. Emerging evidence suggests that CAFs play a crucial role in therapy resistance, including resistance to chemotherapy and radiotherapy. CAFs can modulate the tumor response to treatment by secreting factors that promote drug efflux, enhance DNA repair mechanisms, and suppress apoptosis pathways. This paper aims to understand the multifaceted functions of CAFs within the TME, discusses cross-talk between CAFs with other TME cells, and sheds light on the contibution of CAFs to therapy resistance. Targeting CAFs or disrupting their cross-talk with other cells holds promise for overcoming drug resistance and improving the treatment efficacy of various cancer types.

Hypoxia as a potential inducer of immune tolerance, tumor plasticity and a driver of tumor mutational burden: Impact on cancer immunotherapy

In cancer patients, immune cells are often functionally compromised due to the immunosuppressive features of the tumor microenvironment (TME) which contribute to the failures in cancer therapies. Clinical and experimental evidence indicates that developing tumors adapt to the immunological environment and create a local microenvironment that impairs immune function by inducing immune tolerance and invasion. In this context, microenvironmental hypoxia, which is an established hallmark of solid tumors, significantly contributes to tumor aggressiveness and therapy resistance through the induction of tumor plasticity/heterogeneity and, more importantly, through the differentiation and expansion of immune-suppressive stromal cells. We and others have provided evidence indicating that hypoxia also drives genomic instability in cancer cells and interferes with DNA damage response and repair suggesting that hypoxia could be a potential driver of tumor mutational burden. Here, we reviewed the current knowledge on how hypoxic stress in the TME impacts tumor angiogenesis, heterogeneity, plasticity, and immune resistance, with a special interest in tumor immunogenicity and hypoxia targeting. An integrated understanding of the complexity of the effect of hypoxia on the immune and microenvironmental components could lead to the identification of better adapted and more effective combinational strategies in cancer immunotherapy. Clearly, the discovery and validation of therapeutic targets derived from the hypoxic tumor microenvironment is of major importance and the identification of critical hypoxia-associated pathways could generate targets that are undeniably attractive for combined cancer immunotherapy approaches.