New Strategies and In Vivo Monitoring Methods for Stem Cell-Based Anticancer Therapies

Abstract

Cancer is a devastating disease and the second cause of death in the developed world. Despite significant advances in recent years, such as the introduction of targeted therapies such as receptor tyrosine kinase inhibitors and immunotherapy, current approaches are insufficient to stop the advance of the disease and many cancer types remain largely intractable. In this review, we describe the latest and most revolutionary stem cell-based approaches for the treatment of cancer. We also summarize the emerging imaging modalities being applied for monitoring anticancer stem cell therapy success and discuss the implications of these novel technologies for precision medicine.

Figure 1

Stem cell-based strategies for anticancer therapy. Tumors can be specifically targeted with stem cells to make them vulnerable to therapy. Top: stem cell-based vaccines leverage the similarities between cancer cells and stem cells to promote immune tumor recognition; left: nanoparticle-loaded stem cells exhibit efficient homing to tumors, where they deliver their payload in the form of chemotherapies or apoptosis-inducing oligonucleotides; right: genetically engineered stem cells can express and release proapoptotic proteins or ligands in the tumor microenvironment or contain enzymes metabolizing prodrugs to their cytotoxic form (e.g., cytosine deaminase). Stem cells can also be engineered to recognize biophysical features of the tumor microenvironment before activating their engineered cytotoxic program.

Figure 2

Theranostic magnetic nanoparticles for stem cell anticancer therapy. Iron oxide nanoparticles can be functionalized by applying a dextran coating. Different biologically active substances (antibodies, RNA/DNA, and drugs) intended to target or damage the tumor, or labeling probes for tracing and diagnostics, can be then tethered to the nanoparticle for theranostic applications.