Properties of Heparinoids Premixed with Tumor-Derived Extracellular Vesicles

The Roles of Exosomes in the Diagnose, Development and Therapeutic Resistance of Oral Squamous Cell Carcinoma

Oral cancer is one of the most common cancers worldwide, of which more than half of patients are diagnosed at a locally advanced stage with poor prognosis due to recurrence, metastasis and resistant to treatment. Thus, it is imperative to further explore the potential mechanism of development and drug resistance of oral cancer. Exosomes are small endosome-derived lipid nanoparticles that are released by cells. Since the cargoes of exosomes were inherited from their donor cells, the cargo profiles of exosomes can well recapitulate that of their donor cells. This is the theoretical basis of exosome-based liquid biopsy, providing a tool for early diagnosis of oral cancer. As an important intracellular bioactive cargo delivery vector, exosomes play a critical role in the development of oral cancer by transferring their cargoes to receipt cells. More importantly, recent studies have revealed that exosomes could induce therapy-resistance in oral cancer through multiple ways, including exosome-mediated drug efflux. In this review, we summarize and compare the role of exosomes in the diagnosis, development and therapy-resistant of oral cancer. We also highlight the clinical application of exosomes, and discuss the advantages and challenges of exosomes serving as predictive biomarker, therapy target and therapy vector in oral cancer.

Heparan sulfate analogues regulate tumor-derived exosome formation that attenuates exosome functions in tumor processes

Heparan sulfate (HS) is involved in many biological activities, including the biogenesis and uptake of exosomes, which are related to the occurrence and development of tumors. This study investigated the role of HS analogues (heparin, low molecular weight heparin, and 6-O-desulfated heparin) in modulating exosome secretion, composition and functions. Exosomes derived from B16F10 cells exposed to different HS analogues were isolated and characterized by TEM, western blotting and Nanosight analyses. The number, size and protein cargo of exosomes secreted by HS analogues-induced B16F10 cells were detected. The findings indicated the reduced tumor-derived exosome secretion and protein cargo as reflected by lower levels of CD63, TSG101, heparinase and IL-6 in exosomes derived from heparin-induced B16F10 cells as compared with 6-O-desulfated heparin-induced tumor cells. Further functional assays demonstrated that exosomes from tumor cells exposed to heparin weakened tumor proliferation, migration and invasion most significantly among various exosomes derived from B16F10 cells treated with different HS analogues. Moreover, the sulfate group at 6-O position of heparan sulfate has been proved to play an important role in tumor-derived exosome formation and functions. This study suggested a vital view to develop more specific and efficient HS-based strategies in cancer treatment for targeting tumor-derived exosomes.

Exploring interactions between extracellular vesicles and cells for innovative drug delivery system design

Extracellular vesicles (EVs) are submicron cell-secreted structures containing proteins, nucleic acids and lipids. EVs can functionally transfer these cargoes from one cell to another to modulate physiological and pathological processes. Due to their presumed biocompatibility and capacity to circumvent canonical delivery barriers encountered by synthetic drug delivery systems, EVs have attracted considerable interest as drug delivery vehicles. However, it is unclear which mechanisms and molecules orchestrate EV-mediated cargo delivery to recipient cells. Here, we review how EV properties have been exploited to improve the efficacy of small molecule drugs. Furthermore, we explore which EV surface molecules could be directly or indirectly involved in EV-mediated cargo transfer to recipient cells and discuss the cellular reporter systems with which such transfer can be studied. Finally, we elaborate on currently identified cellular processes involved in EV cargo delivery. Through these topics, we provide insights in critical effectors in the EV-cell interface which may be exploited in nature-inspired drug delivery strategies.

A Polyethylene Glycol-Based Method for Enrichment of Extracellular Vesicles from Culture Supernatant of Human Ovarian Cancer Cell Line A2780 and Body Fluids of High-Grade Serous Carcinoma Patients

Objective

This study tried to evaluate whether 8% polyethylene glycol (PEG) 6000 precipitation combined with differential ultracentrifugation (PPDU) was an efficient and practical method for the enrichment and purification of extracellular vesicles (EVs) derived from the culture supernatant of human ovarian cancer cell line A2780 and from body fluids of patients with high-grade serous carcinoma (HGSC).

Methods

PPDU was used to enrich and purify the EVs derived from body fluids of patients with HSGC and cell culture supernatant of subclones of human ovarian cancer cell line A2780 with high/low invasive capacity (named as A-H/A-L, respectively). Transmission electron microscope (TEM) and nanoparticle tracking analysis (NTA) were used to identificate the EVs size and distribution. Western blots (WB) were used to detect the expression of CD9, CD63, Alix and Calnexin. The high-purity EVs derived from the cell culture supernatant of A-H/A-L were detected by the protein profile. Expression of integrins (ITGs) αV, β1 and β3 in the EVs derived from body fluids of HGSC patients was also evaluated.

Results

The diameter of EVs was about 30–260 nm observed under the TEM. Under the NTA identification, the peak size of EVs was ranged from 70 to 159nm. EVs derived from different specimens did not significantly differ in mean size and peak size. Presence of CD9, CD63 and Alix and absence of Calnexin were confirmed in the EVs. The protein concentrations of EVs’ sample extracted from A-H/A-L cell culture supernatant were 0.36µg/µL and 0.20µg/µL, respectively. The total amount of protein obtained from 300ul EVs was 108.02ug and 61.44ug, respectively. Totally, 2397 peptides and 952 proteins were identified by isobaric tags for relative and absolute quantitation (ITRAQ). The expression of ITGαV, β1, and β3 in the EVs from plasma and ascites of HGSC patients was significantly higher than the control group (plasma: all P<0.0001; ascites: P=0.036, 0.001 and 0.004, respectively). The expression level of ITGαV and β1 in EVs of HGSC’s ascites was significantly higher than that in plasma (P= 0.004, 0.001, respectively). The expression of ITGβ3 was also slightly elevated in EVs-derived HGSC patients’ ascites (P=0.492).

Conclusion

PPDU was an efficient and practical method to enrich EVs from body fluids and cell culture supernatant. The characteristic expression of ITGαV, β1 and β3 in ascites and plasma EVs of patients with HGSC provided useful information on the development of EVs in HGSC.

Crosstalk between Stress Granules, Exosomes, Tumour Antigens, and Immune Cells: Significance for Cancer Immunity

RNA granules and exosomes produced by tumour cells under various stresses in the microenvironment act as critical determinants of cell survival by promoting angiogenesis, cancer metastasis, chemoresistance, and immunosuppression. Meanwhile, developmental cancer/testis (CT) antigens that are normally sequestered in male germ cells of the testes, but which are overexpressed in malignant tumour cells, can function as tumour antigens triggering immune responses. As CT antigens are potential vaccine candidates for use in cancer immunotherapy, they could be targeted together with crosstalk between stress granules, exosomes, and immune cells for a synergistic effect. In this review, we describe the effects of exosomes and exosomal components presented to the recipient cells under different types of stresses on immune cells and cancer progression. Furthermore, we discuss their significance for cancer immunity, as well as the outlook for their future application.