Metastatic colorectal cancer (mCRC) is a major cause of cancer-related mortality due to the absence of effective therapeutics. Thus, it is urgent to discover new drugs for mCRC. Fucosyltransferase 8 (FUT8) is a potential therapeutic target with high level in most malignant cancers including CRC. FUT8 mediates the core fucosylation of CD276 (B7-H3), a key immune checkpoint molecule (ICM), in CRC. FUT8-silence-induced defucosylation at N104 on B7-H3 attracts heat shock protein family A member 8 (HSPA8, also known as HSC70) to bind with 106-110 SLRLQ motif and consequently propels lysosomal proteolysis of B7-H3 through the chaperone-mediated autophagy (CMA) pathway. Then we report the development and characterization of a potent and highly selective small-molecule inhibitor of FUT8, named FDW028, which evidently prolongs the survival of mice with CRC pulmonary metastases (CRPM). FDW028 exhibits potent anti-tumor activity by defucosylation and impelling lysosomal degradation of B7-H3 through the CMA pathway. Taken together, FUT8 inhibition destabilizes B7-H3 through CMA-mediated lysosomal proteolysis, and FDW028 acts as a potent therapeutic candidate against mCRC by targeting FUT8.

Extracellular vesicles (EVs) as the new form of cellular communication have been demonstrated their potential use for disease diagnosis, prognosis and treatment. EVs are vesicles with a lipid bilayer and are present in various biofluids, such as blood, saliva and urine. Therefore, EVs have emerged as one of the most appealing sources for the discovery of clinical biomarkers. However, isolation of the target EVs from different biofluids is required for the use of EVs as diagnostic and therapeutic entities in clinical settings. Owing to their unique properties and versatile functionalities, nanomaterials have been widely investigated for EV isolation with the aim to provide rapid, simple, and efficient EV enrichment. Herein, this review presents the progress of nanomaterial-based isolations for EVs over the past five years (from 2017 to 2021) and discusses the use of nanomaterials for EV isolations based on the underlying mechanism in order to offer insights into the design of nanomaterials for EV isolations.

A schematic diagram of material-based isolation methods for EVs.

SRSF3, an important member of the serine/arginine-rich protein (SRp) family, is highly expressed in various tumors and plays an important role in tumor cell proliferation, migration and invasion. However, it is still unclear whether SRSF3 is involved in tumor angiogenesis. In this study, we first revealed that SRSF3 regulated the expression of numerous genes related to angiogenesis, including proangiogenic SRF. Then, we confirmed that SRSF3 was highly expressed in colorectal cancer (CRC) and was positively correlated with SRF. Mechanistic studies revealed that SRSF3 directly bound to the “CAUC” motif in exon 6 of SRF and induced the exclusion of introns. Knockdown of SRSF3 significantly reduced the secretion of VEGF from CRC cells. Conditioned medium from SRSF3-knockdown CRC cells significantly inhibited the migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs). In addition, SRF silencing inhibited angiogenesis, while SRF overexpression reversed the antiangiogenic effects of SRSF3 knockdown on tube formation. These findings indicate that SRSF3 is involved in the splicing of SRF and thereby regulates the angiogenesis of CRC, which offers novel insight into antiangiogenic therapy in CRC.