Exosomes in Cancer and Inflammatory Diseases

In cancer cells, exosomes and other EVs transport cargo that is implicated in each stage of tumor growth and metastasis. For instance, cancerous cells can secrete EVs containing growth factors that have multiple roles in tumor growth and metastasis, including the induction of epithelial-to-mesenchymal transition (EMT), the transformation of normal cells into malignant cells, and the increased stemness of cancer cells.

Additionally, oncogenic cells can secrete EVs containing anti-apoptotic factors, like Survivin, to prevent cell death, and growth factors, like VEGF, to increase angiogenesis in the tumor microenvironment (TME).

Read EMT and Stemness FAQs

NSCLC, Non small-cell lung cancer; NPC, Nasopharyngeal carcinoma; GIST, Gastrointestinal stromal tumor

To be successful, tumors need to evade and suppress the immune response of the host. Some mechanisms of immunosuppression in the tumor microenvironment (TME) include cytotoxic inhibition of NK cells and effector T cells, expansion and activation of T regulatory (T_reg) cells, and polarization of M2 macrophages. EVs including exosomes play an important role in each of these immunosuppressive processes.

NSCLC, non-small cell lung cancer; NPC, nasopharyngeal carcinoma

In addition to tumor metastasis and immunosuppression, exosomes and other EVs can contribute to tumor growth and disease progression by directly promoting resistance to anti-cancer therapy. EVs can transfer material, such as multi-drug resistant (MDR)-associated proteins and miRNAs to susceptible cells, transforming them into therapy-resistant cells. Additionally, drugs and drug metabolites can be encapsulated within EVs to facilitate transport out of the tumor cell, rendering the drug ineffective. Finally, due to their expression of cell surface markers that are also targets for therapy, such as CD20, Her-2, and PD-L1, EVs can serve as decoy targets, limiting therapeutic efficacy.

In general, a biomarker is a biological characteristic that can be measured and monitored. Biomarkers are an especially useful tool for the diagnosis and monitoring of cancer when the primary tumor site is in a hard-to-reach place, such as the brain or other solid organ.

EVs are under investigation as biomarkers to:

• diagnose disease,
• determine disease burden, and
• monitor disease progression and/or treatment efficacy.

Learn more about Bio-Techne's Exosome Platform for diagnostic biomarker discovery and development. 

Exosomes and other EVs are implicated in the pathogenesis of many inflammatory diseases including cardiovascular disease, kidney disease, autoimmune disorders, and viral infections. Thus far, much of this work has investigated the role of various microRNAs (miRNAs) and protein cargo, the role of exosomes in inflammatory disease is being increasingly studied.