In vitro disease modeling can be used both for understanding the development of pathology and for screening various therapies, such as gene therapies. This approach decreases costs, shortens research timelines, reduces animal testing, and may be more accurate in replicating the disease phenotype compared to animal models. This review focuses on the two types of stem cells: induced pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSCs), which can be used for this purpose. Special attention is given to the impact of the isolation source and the variable expression of certain phenotypic markers on the differentiation capacity of these cells. Both similarities and critical differences between iPSCs and MSCs, as well as the outcomes of past and ongoing clinical trials, are discussed in order to gain insight and understanding as to which of these two cell types can be more suitable for the particular biomedical application.

Anti-cancer therapy based on oncolytic viruses (OVs) is a targeted approach that takes advantage of OVs’ ability to selectively infect and replicate in tumor cells, activate the host immune response, and destroy malignant cells over healthy ones. Vesicular stomatitis virus (VSV) is known for its wide range of advantages: a lack of pre-existing immunity, a genome that is easily amenable to manipulation, and rapid growth to high titers in a broad range of cell lines, to name a few. VSV-induced tumor immunity can be enhanced by the delivery of immunostimulatory cytokines. The targeted cytokine delivery to tumors avoids the significant toxicity associated with systemic delivery while also boosting the immune response. To demonstrate this enhanced effect on both tumor growth and survival, a novel recombinant VSV (rVSV)-mIL12-mGMCSF, co-expressing mouse IL-12 (interleukin-12) and GM-CSF (granulocyte-macrophage colony-stimulating factor), was tested alongside rVSV-dM51-GFP (rVSV-GFP) that was injected intratumorally in a syngeneic in vivo C57BL/6 mouse model infused subcutaneously with B16-F10 melanoma cells. The pilot study tested the effect of two viral injections 4 days apart and demonstrated that treatment with the two rVSVs resulted in partial inhibition of tumor growth (TGII of around 40%) and an increased survival rate in animals from the treatment groups. The effect of the two VSVs on immune cell populations will be investigated in future in vivo studies with an optimized experimental design with multiple higher viral doses, as a lack of this information presents a limitation of this study.

Oncolytic viruses (OVs) represent a targeted anti-cancer therapy approach due to their ability not only to selectively infect and destroy malignant cells but also to induce an immune response. Vesicular stomatitis virus (VSV) offers a promising platform due to its low prevalence and pathogenicity in humans, lack of pre-existing immunity, easily manipulated genome, rapid growth to high titers in a broad range of cell lines, and inability to integrate into the host genome. However, despite its many advantages, many unresolved problems remain: problematic production based on the reverse genetics system, oncological selectivity, and the overall effectiveness of VSV monotherapy. This review will discuss various attempts at viral genome modifications aimed at improving the oncolytic properties of VSV. These strategies include inhibition of viral genes, modification of genes responsible for targeting cancer cells over healthy ones, insertion of foreign genes for boosting immune response, and changing the order of viral and inserted foreign genes. In addition, possible ways to improve VSV-based anti-tumor therapy and achieve higher efficiency will be considered by evaluating the effectiveness of various delivery methods as well as discussing treatment options by combining VSV with other groups of anticancer drugs.

Interferons (IFNs) are well-known immunostimulants involved in both innate and adaptive immune responses. These multifunctional proteins mediate an early antiviral response and have pronounced immunomodulatory and antiproliferative properties. Due to their potency, IFNs have been used not only in the treatment of viral infections but also various other diseases. However, the use of IFNs in antitumor therapy has been limited by the frequent severe side effects, which reduced their appeal for the treatment of cancer. In this review, we focused on current data on recombinant IFNs used for anticancer therapy, as well as the development of promising IFN-based gene therapy approaches, with a focus on their safety and therapeutic efficacy. We also highlighted various types of IFNs and their application niches in the treatment of not only cancers in combination therapy but also of certain rare diseases. Taken together, this review improves our understanding of the existing IFN applications in cancer therapy, the disadvantages of using IFNs, and possible approaches for their improvement.

The unique ability of oncolytic viruses (OVs) to replicate in and destroy malignant cells while leaving healthy cells intact and activating the host immune response makes them powerful targeted anti-cancer therapeutic agents. Vesicular stomatitis virus (VSV) only causes mild and asymptomatic infection, lacks pre-existing immunity, can be genetically engineered for enhanced efficiency and improved safety, and has a broad cell tropism. VSV can facilitate targeted delivery of immunostimulatory cytokines for an enhanced immune response against cancer cells, thus decreasing the possible toxicity frequently observed as a result of systemic delivery. In this study, the oncolytic potency of the two rVSV versions, rVSV-dM51-GFP, delivering green fluorescent protein (GFP), and rVSV-dM51-mIL12-mGMCSF, delivering mouse interleukin-12 (mIL-12) and granulocyte-macrophage colony-stimulating factor (mGMCSF), was compared on the four murine cancer cell lines of different origin and healthy mesenchymal stem cells (MSCs) at 24 h post-infection by flow cytometry. Lewis lung carcinoma (LL/2) cells were demonstrated to be more susceptible to the lytic effects of both rVSV versions compared to melanoma (B16-F10) cells. Detection of expression levels of antiviral and pro-apoptotic genes in response to the rVSV-dM51-GFP infection by quantitative PCR (qPCR) showed lower levels of IFIT, RIG-I, and N-cadherin and higher levels of IFNβ and p53 in LL/2 cells. Subsequently, C57BL/6 mice, infused subcutaneously with the LL/2 cells, were injected intratumorally with the rVSV-dM51-mIL12-mGMCSF 7 days later to assess the synergistic effect of rVSV and immunostimulatory factors. The in vivo study demonstrated that treatment with two rVSV-dM51-mIL12-mGMCSF doses 3 days apart resulted in a tumor growth inhibition index (TGII) of over 50%.

The search for effective anti-cancer therapies is one of the most significant goals of modern medicine. The combination of oncolytic viruses (OV) and mRNA immunoadjuvants can significantly improve the outcome or even substitute traditional immunotherapy. In addition to the direct OV-mediated cytotoxic elimination of tumor cells, both OV and mRNA immunoadjuvants can significantly alter the immunosuppressive tumor microenvironment (TME) supporting cancer cells and unleash the immune response against the malignant cells. The present study is aimed at assessing the therapeutic effects of recombinant vesicular stomatitis virus (rVSV) and lipid nanoparticles (LNP) delivering mRNA coding for murine interleukin-12 (mIL12) and granulocyte-macrophage colony-stimulating factor (mGMCSF) (mRNA-LNP) in colorectal carcinoma CT26-induced tumors both as independent therapies and in combination with each other. The results of the in vivo experiment on BALB/c mice demonstrated that rVSV monotherapy did not have a significant effect, with the tumor growth inhibition index (TGII) ranging from 13.7 to 29.8% on days 6–10 after the therapy start. While monotherapy with mRNA-LNP was more effective (TGII of 48.6–53.7%), it was the therapy combining the two approaches (rVSV and mRNA-LNP) that resulted in the highest TGII of 66.7% on day 10. While these results can be further improved by optimizing the experimental design, they show the great potential of combination immunotherapy for the treatment of oncological diseases.