Exosomes in tumor‐stroma crosstalk: Shaping the immune microenvironment in colorectal cancer

Colorectal cancer (CRC) is a multifaceted disease characterized by a complex interaction between tumor cells and the surrounding microenvironment. Within this intricate landscape, exosomes have emerged as pivotal players in the tumor‐stroma crosstalk, influencing the immune microenvironment of CRC. These nano‐sized vesicles, secreted by both tumoral and stromal cells, serve as molecular transporters, delivering a heterogeneous mix of biomolecules such as RNAs, proteins, and lipids. In the CRC context, exosomes exert dual roles: they promote tumor growth, metastasis, and immune escape by altering immune cell functions and activating oncogenic signaling pathways and offer potential as biomarkers for early CRC detection and treatment targets. This review delves into the multifunctional roles of exosomes in the CRC immune microenvironment, highlighting their potential implications for future therapeutic strategies and clinical outcomes. The communication between tumor cells and surrounding stromal cells through exosomes. The focus is mainly on recent developments in exosome research, particularly on the vesicles that originate from stromal cells such as cancer‐associated fibroblasts, mesenchymal stem cells, and macrophages within the tumor microenvironment in colorectal cancer.