Role of hypoxia-induced exosomes in tumor biology

Abstract

Purpose: Hypoxia is a major regulator of angiogenesis and always influences the release of exosomes in various types of tumors. The present review aimed to assess the role of hypoxia-induced exosomes in the tumor biology.

Methods: The relevant publications were retrieved from PubMed using keywords such as hypoxia, exosome, extracellular vesicles, tumor, cancer, and other similar terms.

Results: Recent studies have shown that cancer cells produce more exosomes under hypoxic conditions than do parental cells under normoxic conditions. The secretion and function of exosomes could be influenced by hypoxia in various types of cancer. Hypoxia-induced exosomes play critical roles in tumor angiogenesis, invasion, metastasis, and the immune system.

Conclusions: These findings provide new insights into the complex networks underlying cellular and genomic regulation in response to hypoxia and might provide novel and specific targets for future therapies.

Keywords: Cancer; Exosome; Extracellular vesicles; Hypoxia.

Fig. 1

Hypoxic-induced exosomes promote angiogenesis in multiple cancers. Under chronic hypoxic conditions, cancer cells secrete higher levels of exosomes. The upregulated exosomal ncRNAs and specific proteins induced by hypoxia are taken up by the surrounding endothelial cells, resulting in the accelerated angiogenesis

Fig. 2

Exosomes and microvesicles derived from hypoxic tumors are involved in the immune response of tumor microenvironment, including regulation of T-cell proliferation, inhibition of NK cells, activation of macrophages, and promotion of their polarization