Specific molecular weight of Lycium barbarum polysaccharide for robust breast cancer regression by repolarizing tumor-associated macrophages.

The pro-tumorigenic M2-type tumor-associated macrophages (TAMs) in the immunosuppressive tumor microenvironment (TME) promote the progression, angiogenesis, and metastasis of breast cancer. The repolarization of TAMs from an M2-type toward an M1-type holds great potential for the inhibition of breast cancer. Here, we report that Lycium barbarum polysaccharides (LBPs) can significantly reconstruct the TME by modulating the function of TAMs. Specifically, we separated four distinct molecular weight segments of LBPs and compared their repolarization effects on TAMs in TME. The results showed that LBP segments within 50-100 kDa molecular weight range exhibited the prime effect on the macrophage repolarization, augmented phagocytosis effect of the repolarized macrophages on breast cancer cells, and regression of breast tumor in a tumor-bearing mouse model. In addition, RNA-sequencing confirms that this segment of LBP displays an enhanced anti-breast cancer effect through innate immune responses. This study highlights the therapeutic potential of LBP segments within the 50-100 kDa molecular weight range for macrophage repolarization, paving ways to offer new strategies for the treatment of breast cancer.

[Structure-activity relationship of Lycium barbarum polysaccharides].

As a traditional Chinese herb and functional food, the fruits of Lycium barbarum has been widely used for thousands of years in China. L. barbarum polysaccharides(LBPs) are predominant active components, which have immunomodulatory, antioxidant, hypoglycemic, neuroprotective, anti-tumor, and prebiotic activities. The molecular weight, monosaccharide composition, glycosidic bond, branching degree, protein content, chemical modification, and spatial structure of LBPs are closely related to their biological activity. Based on the previous studies of this research team, this paper systematically combed and integrated the research progress of structure, function, and structure-activity relationship of LBPs. At the same time, some problems restricting the clarification of the structure-activity relationship of LBPs were considered and prospected, hoping to provide references for the high value utilization of LBPs and in-depth exploration of their health value.