Recent advances in targeting cancer stem cells using oncolytic viruses

The role of oncolytic virotherapy and viral oncogenes in the cancer stem cells: a review of virus in cancer stem cells

Cancer Stem Cells (CSCs) are the main "seeds" for the initiation, growth, metastasis, and recurrence of tumors. According to many studies, several viral infections, including the human papillomaviruses, hepatitis B virus, Epstein-Barr virus, and hepatitis C virus, promote the aggressiveness of cancer by encouraging the development of CSC features. Therefore, a better method for the targeted elimination of CSCs and knowledge of their regulatory mechanisms in human carcinogenesis may lead to the development of a future tool for the management and treatment of cancer. Oncolytic viruses (OVs), which include the herpes virus, adenovirus, vaccinia, and reovirus, are also a new class of cancer therapeutics that have favorable properties such as selective replication in tumor cells, delivery of numerous eukaryotic transgene payloads, induction of immunogenic cell death and promotion of antitumor immunity, as well as a tolerable safety profile that essentially differs from that of other cancer therapeutics. The effects of viral infection on the development of CSCs and the suppression of CSCs by OV therapy were examined in this paper. The purpose of this review is to investigate the dual role of viruses in CSCs (oncolytic virotherapy and viral oncogenes).

Update on immune-based therapy strategies targeting cancer stem cells

Accumulating data reveals that tumors possess a specialized subset of cancer cells named cancer stem cells (CSCs), responsible for metastasis and recurrence of malignancies, with various properties such as self-renewal, heterogenicity, and capacity for drug resistance. Some signaling pathways or processes like Notch, epithelial to mesenchymal transition (EMT), Hedgehog (Hh), and Wnt, as well as CSCs' surface markers such as CD44, CD123, CD133, and epithelial cell adhesion molecule (EpCAM) have pivotal roles in acquiring CSCs properties. Therefore, targeting CSC-related signaling pathways and surface markers might effectively eradicate tumors and pave the way for cancer survival. Since current treatments such as chemotherapy and radiation therapy cannot eradicate all of the CSCs and tumor relapse may happen following temporary recovery, improving novel and more efficient therapeutic options to combine with current treatments is required. Immunotherapy strategies are the new therapeutic modalities with promising results in targeting CSCs. Here, we review the targeting of CSCs by immunotherapy strategies such as dendritic cell (DC) vaccines, chimeric antigen receptors (CAR)-engineered immune cells, natural killer-cell (NK-cell) therapy, monoclonal antibodies (mAbs), checkpoint inhibitors, and the use of oncolytic viruses (OVs) in pre-clinical and clinical studies. This review will mainly focus on blood malignancies but also describe solid cancers.

Materials promoting viral gene delivery

Therapeutic viral gene delivery is an emerging technology which aims to correct genetic mutations by introducing new genetic information to cells either to correct a faulty gene or to initiate cell death in oncolytic treatments. In recent years, significant scientific progress has led to several clinical trials resulting in the approval of gene therapies for human treatment. However, successful therapies remain limited due to a number of challenges such as inefficient cell uptake, low transduction efficiency (TE), limited tropism, liver toxicity and immune response. To adress these issues and increase the number of available therapies, additives from a broad range of materials like polymers, peptides, lipids, nanoparticles, and small molecules have been applied so far. The scope of this review is to highlight these selected delivery systems from a materials perspective.