Cancer, standing as the predominant cause of global mortality, claims the lives of over 10 million individuals annually across more than 200 distinct cancer types (2). Despite the multitude of proposed treatments, the intricate nature of cancer has severely limited the effectiveness of current therapeutic methods. The formidable challenge arises from the inherent difficulty of our immune system to discern cancer cells from their healthy counterparts. Conventional treatments like radiation and chemotherapy, while targeting cancer cells, inevitably impact healthy cells, resulting in deleterious side effects. The systemic administration of chemotherapy, circulating throughout the body via the bloodstream, further compounds these issues, causing side effects and accumulation in non-target tissues. Additionally, the emergence of cancer resistance to existing drugs necessitates exploration into novel drug combinations and delivery systems (4).
Nanotechnology, with its unique attributes facilitating high efficiency in tumor targeting and drug preservation, emerges as a promising avenue to fortify cancer treatments, particularly through biological nanoparticles. Exosomes, small particles ranging from 30 to 100 nm enclosed in two lipid layers, serve as natural nanocarriers capable of protecting and transporting biologically active molecules, including proteins, lipids, and nucleic acids. Originating from endosomes, exosomes are released from parent cells following the fusion of multivesicular bodies (MVBs) with the plasma membrane. This intricate process results in the release of exosomes, a subset of extracellular vesicles (EVs), secreted by various cells. The advantages of exosomes over traditional liposomes lie in their higher binding and entry into tumor cells, approximately tenfold greater for exosomes of the same size (1). Moreover, nanometric exosomes exhibit increased permeability and durability, leading to their preferential accumulation in tumor tissues with abnormal blood vessels compared to normal tissues. Other notable characteristics of exosomes include biocompatibility, non-cytotoxicity, and the ability to control immunogenicity, rendering them powerful tools for the delivery of anti-cancer drugs. Exosomes play a pivotal role in cell-cell communication, participating in several physiological and pathological processes, showcasing their potential as innovative treatment strategies for various diseases (14).
In this review, we investigated several articles published in recent years, examining the utilization of exosomes in cancer treatment. The objective is to offer an overview of some of the most innovative studies conducted between 2014 and 2023, highlighting new methods leveraging the favorable features of exosomes in cancer treatment. Immunotherapy, a significant approach in cancer treatment, encounters challenges, primarily the evasion of cancer cells from the body's immune response and the suppression of immune responses by the tumor microenvironment. Addressing these challenges involves double immunotherapy treatments with drugs altering the tumor microenvironment, intensifying the immune system's response to cancer cells. Notably, the review emphasizes that this immune system response intensification or induction can be achieved through methods other than stimulating antigen supply, eliminating the need to load effective molecules inside exosomes.
Over the past decade, exosomes have garnered significant interest in cancer treatment due to their unique biocompatibility, high stability, and increasing effectiveness as biological nanocarriers. The literature on exosomes' use in cancer treatment has grown substantially, reflecting their potential beyond drug delivery. Exosomes exhibit the capacity to modulate the immune system, enhancing its ability to recognize and combat cancer cells effectively (6-9). Furthermore, exosomes can contribute to the development of biological vaccines aimed at eliminating tumors without traditional drug interventions. Clinical trials involving various exosomes from human sources have demonstrated their inherent ability to cross the blood-brain barrier, rendering them effective in treating central nervous system diseases. Noteworthy is the use of dendritic cells (DCs) as a cell source for exosomes in inducing inflammatory responses in cancer patients (5,21,14).
Despite the promising clinical applications of exosomes, the path forward presents various questions and challenges. A key challenge revolves around the controversy surrounding exosomes, with some exhibiting beneficial effects, such as those released from B cells and dendritic cells. In contrast, exosomes secreted from tumor cells have been observed to enhance tumor invasion and angiogenesis while concurrently suppressing the immune response (2).
In conclusion, exosomes emerge as promising platforms for disease treatment in clinical trials, offering distinct advantages over common chemotherapy and radiotherapy treatments, particularly in targeting nanocarriers. This dynamic field is evolving rapidly, and the understanding of the underlying mechanisms governing the diverse roles of exosomes remains incomplete, necessitating further multidisciplinary research with these small vesicles. As this promising field continues to captivate the scientific community, it sets the stage for continued exploration and innovation in leveraging exosomes for the benefit of cancer patients worldwide.
The potential of exosomes in cancer treatment is vast and warrants a deeper exploration of their mechanisms and applications. Researchers and clinicians alike are encouraged to delve into the intricacies of exosome-mediated therapies to unlock their full potential in revolutionizing cancer treatment paradigms. With advancements in our understanding of exosomes and their role in cancer therapy, there is an opportunity to reshape the landscape of cancer treatment, providing patients with more effective and targeted options. As we navigate this exciting frontier of medical science, collaboration and continued research will be key in realizing the full therapeutic potential of exosomes in the fight against cancer.
The landscape of cancer treatment is evolving, and exosomes offer a promising avenue for further exploration and innovation. As we transition from the era of conventional therapies to more targeted and personalized approaches, exosomes may play a pivotal role in shaping the future of cancer treatment. The ongoing research and clinical trials centered around exosomes underscore their potential to revolutionize how we perceive and manage cancer.
In the quest for more effective and less harmful cancer treatments, exosomes represent a beacon of hope. Their natural origin, biocompatibility, and ability to transport a diverse range of therapeutic payloads make them valuable assets in the fight against cancer. As we journey towards a future where cancer is more effectively controlled and treated, the role of exosomes will likely become increasingly prominent.
While the journey is promising, it is not without challenges. The controversy surrounding the effects of exosomes, especially those originating from tumor cells, poses a critical question that demands careful consideration and further investigation. Understanding the nuances of exosome-mediated interactions within the complex tumor microenvironment is essential for refining their therapeutic applications.
In conclusion, exosomes offer a multifaceted approach to revolutionizing cancer treatment. From their role as efficient drug delivery vehicles to their involvement in modulating the immune system and potential use in developing biological vaccines, exosomes present a versatile toolkit for researchers and clinicians. The journey from bench to bedside involves addressing challenges, refining techniques, and unraveling the intricacies of exosome biology. As the scientific community continues to unravel the mysteries of these tiny vesicles, the potential for exosomes to significantly impact cancer treatment remains high. With collaborative efforts and a commitment to pushing the boundaries of knowledge, exosomes may well emerge as transformative agents in the global battle against cancer.