Therapeutic Efficacy of Oncolytic Viruses in Fighting Cancer: Recent Advances and Perspective

Abstract

Immunotherapy is at the cutting edge of modern cancer treatment. Innovative medicines have been developed with varying degrees of success that target all aspects of tumor biology: tumors, niches, and the immune system. Oncolytic viruses (OVs) are a novel and potentially immunotherapeutic approach for cancer treatment. OVs reproduce exclusively in cancer cells, causing the tumor mass to lyse. OVs can also activate the immune system in addition to their primary activity. Tumors create an immunosuppressive environment by suppressing the immune system’s ability to respond to tumor cells. By injecting OVs into the tumor, the immune system is stimulated, allowing it to generate a robust and long-lasting response against the tumor. The essential biological properties of oncolytic viruses, as well as the underlying mechanisms that enable their usage as prospective anticancer medicines, are outlined in this review. We also discuss the increased efficacy of virotherapy when combined with other cancer medications.

Tumor Microenvironment Immunosuppression: A Roadblock to CAR T-Cell Advancement in Solid Tumors

“…Sustained ICD causes activation of an immune response that alters the TME through increased infiltration of immune cells stimulated by the release of antigens from lysed tumor cells [ 132 ]. There is currently one oncolytic virus approved by the FDA (discussed further below), and there are over 400 clinical trials for varying oncolytic viruses which have achieved varying anti-tumor success both as monotherapies and in conjunction with other immunotherapies [ 133 , 134 , 135 ]. However, current discoveries suggest that oncolytic viruses as a monotherapy are not likely to be fully effective due to the heterogenicity of cancer and its complex, dynamic nature [ 129 ].…”

Oncolytic Viruses for the Treatment of Bladder Cancer: Advances, Challenges, and Prospects

“…In preclinical and clinical studies, several OVs have been studied for the treatment of BC; however, the precise anticancer mechanisms of OV in BC are still not well understood and may differ from virus to virus. As shown in Figure 1 , the main antitumor mechanisms include [ 15 ]:…”

“…In addition, some OVs are molecularly engineered to infect cancer cells specifically [ 11 ]. Once infection takes hold, OVs will take control of the tumor cell’s production line for nucleic acids and proteins, preventing the cancer cells from producing enough nucleic acids and proteins to meet their growth requirements and destroying their normal physiological processes [ 15 ]. The viruses cause alterations in cell function and ultimately kill and lyse the cancer cells by damaging organelles [ 19 , 20 , 21 , 22 ].…”

Efficacy and safety of oncolytic virus combined with chemotherapy or immune checkpoint inhibitors in solid tumor patients: A meta-analysis

“…Chemotherapy is a traditional treatment for cancer. However, it often does not produce satisfactory results due to its cytotoxicity, low targeting, drug resistance, intolerable side effects, and high risk of recurrence ( Garmaroudi et al, 2022 ). In recent years, immune checkpoint inhibitors (ICIs) have emerged as a cancer treatment.…”

“…OV therapy began in 1904. A woman with chronic leukemia was reported to have unexpectedly improved after contracting influenza ( Garmaroudi et al, 2022 ). OVs are divided into oncolytic RNA viruses and oncolytic DNA viruses.…”