Yeast-Derived β-Glucan in Cancer: Novel Uses of a Traditional Therapeutic

An increased understanding of the complex mechanisms at play within the tumor microenvironment (TME) has emphasized the need for the development of strategies that target immune cells within the TME. Therapeutics that render the TME immune-reactive have a vast potential for establishing effective cancer interventions. One such intervention is beta-glucan, a natural compound with immune-stimulatory and immunomodulatory potential that has long been considered an important anti-cancer therapeutic. beta-glucan has the ability to modulate the TME both by bridging the innate and adaptive arms of the immune system and by modulating the phenotype of immune-suppressive cells to be immune-stimulatory. New roles for beta-glucan in cancer therapy are also emerging through an evolving understanding that beta-glucan is involved in a concept called trained immunity, where innate cells take on memory phenotypes. Additionally, the hollow structure of particulate beta-glucan has recently been harnessed to utilize particulate beta-glucan as a delivery vesicle. These new concepts, along with the emerging success of combinatorial approaches to cancer treatment involving beta-glucan, suggest that beta-glucan may play an essential role in future strategies to prevent and inhibit tumor growth. This review emphasizes the various characteristics of beta-glucan, with an emphasis on fungal beta-glucan, and highlights novel approaches of beta-glucan in cancer therapy.