The Role of Vesicular Stomatitis Virus Matrix Protein in Autophagy in the Breast Cancer

Cancer-Specific Activation of the Vesicular Stomatitis Virus Matrix by Survivin Promoter in Breast Cancer Cells

Oncolytic viral-based therapy and specific gene expression by promoters are modern targeted oncotherapy approaches that have gained significant attention in recent years. In this study, both strategies were combined by designing cancer-specific activation of vesicular stomatitis virus matrix expression under the survivin promoter. The matrix sequence was cloned downstream of the survivin promoter (pM). After transfecting MCF-7 cells with pM, cell proliferation and apoptosis induction were assessed. Additionally, the transcript levels of matrix and apoptosis-related genes in response to pM was assessed. The proliferation of MCF-7 cells was significantly reduced by the constructed matrix-expressing plasmid at 48 and 72 h post-transfection (p < 0.05). Enhanced matrix expression resulted in the down-regulation of MMP-9, TP53, and NF-kB, while simultaneously up-regulating Bax transcripts. Evaluating the effect of pM vector on apoptosis induction revealed a significant increase in the MCF-7 cells compared to untreated cells (p < 0.05). The absence of significant matrix gene expression in HDF cells, relative to MCF-7 cells, further underscores the specific function of the Survivin promoter in cancer cells. These findings suggest that the matrix may have various biological functions in a diverse set of non-apoptotic pathways. Further research on the association of the matrix with other genes could provide insights into the biomedical significance and future perspectives of the matrix in cancer gene therapy.

Employing the Oncolytic Vesicular Stomatitis Virus in Cancer Virotherapy: Resistance and Clinical Considerations

Vesicular Stomatitis Virus (VSV) has emerged as a promising candidate for various clinical applications, including vaccine development, virus pseudotyping, and gene delivery. Its broad host range, ease of propagation, and lack of pre-existing immunity in humans make it ideal for therapeutic use. VSV's potential as an oncolytic virus has garnered attention; however, resistance to VSV-mediated oncolysis has been observed in some cell lines and tumor types, limiting its effectiveness. This review provides a detailed analysis of recent advances in VSV-based oncolysis, focusing on resistance mechanisms such as sustained type-I IFN signaling, upregulation of ISGs, immune cell activation, the tumor microenvironment (TME), and tumor-intrinsic factors. Strategies to overcome resistance include enhancing viral oncoselectivity, inhibiting IFN responses, modulating the TME, and combining VSV with chemotherapies, radiation, and immune checkpoint inhibitors. Several VSV-based phase I/II clinical trials show promise; however, addressing resistance and developing novel strategies to enhance therapeutic efficacy are essential for realizing the full potential of VSV oncolytic virotherapy. Future research should focus on patient-specific approaches, as tumor heterogeneity implies varying resistance mechanisms. Personalized treatments tailored to tumor molecular profiles, along with identifying biomarkers predictive of resistance to VSV oncolysis, will enhance patient selection and enable more effective, individualized VSV-based therapies.

Oncolytic viruses-modulated immunogenic cell death, apoptosis and autophagy linking to virotherapy and cancer immune response

Recent reports have revealed that oncolytic viruses (OVs) play a significant role in cancer therapy. The infection of OVs such as oncolytic vaccinia virus (OVV), vesicular stomatitis virus (VSV), parvovirus, mammalian reovirus (MRV), human adenovirus, Newcastle disease virus (NDV), herpes simplex virus (HSV), avian reovirus (ARV), Orf virus (ORFV), inactivated Sendai virus (ISV), enterovirus, and coxsackievirus offer unique opportunities in immunotherapy through diverse and dynamic pathways. This mini-review focuses on the mechanisms of OVs-mediated virotherapy and their effects on immunogenic cell death (ICD), apoptosis, autophagy and regulation of the immune system.

Multifunctional theranostic nanoplatform loaded with autophagy inhibitor for enhanced photothermal cancer therapy under mild near-infrared irradiation

Photothermal therapy (PTT) usually causes hyperthermia and damages healthy tissues. Developing a PTT platform with enhanced therapeutic effects and reduced side effects to normal tissues attracts increasing attention. Herein, we developed a multifunctional theranostic nanoplatform using poly(lactic-co-glycolic acid) (PLGA) loaded with near-infrared (NIR) photothermal agent (new indocyanine green IR820), fluorescence imaging agent (ZnCdSe/ZnS quantum dots, QDs) and autophagy inhibitor (chloroquine, CQ). These PLGA/IR820/Fluorescence imaging agent/CQ co-loading nanoparticles (termed PIFC NPs) displayed photothermal effects, enhanced the stability of IR820 in vivo, and enabled QDs to have stable fluorescent signals in vitro and in vivo. The PIFC NPs with particle size around 240 nm aggregated to tumor sites through the high permeability and retention effects of solid tumors. The intracellular delivery of CQ molecules through PIFC NPs significantly attenuated the degradation of autophagic lysosomes in tumor cells and effectively inhibited the autophagy mediated repair of photothermal damaged cells. Under milder NIR irradiation conditions, PIFC NPs exhibited high antitumor effect. By regulating autophagy, PTT can be effectively sensitized, which will provide a new idea for future cancer treatment research.

NEBL and AKT1 maybe new targets to eliminate the colorectal cancer cells resistance to oncolytic effect of vesicular stomatitis virus M-protein

This study compares the oncolytic effect of vesicular stomatitis virus (VSV) wild type and M51R M-protein on the colorectal tumors of different invasive intensity on SW480 and HCT116 cell lines and 114 fresh colorectal cancer primary cell cultures. Fresh tumor samples were divided into two groups of lower stages (I/II) and higher stages (III/IV) regarding the medical records. The presence of two mutations in the PIK3CA gene and the expression of NEBL and AKT1 genes were evaluated. The cells were transfected with a plasmid encoding VSV wild-type and M51R mutant M-protein. Results showed either wild type or M51R mutant can kill SW480 and stage I/II primary cultures while mutant M-protein had no apoptotic effects on HCT116 cells and stage III/IV primary cultures. NEBL and AKT1 expression were significantly higher in resistant cells. Elevated caspase-9 activity confirmed that the intrinsic apoptosis pathway is the reason for cell death in lower-stage cells. Different tumors from the same cancer exhibit different treatment sensitivity due to genetic difference. NEBL and AKT1 gene expression may be responsible for this difference, which may be the target of future investigations. Therefore, tumor staging should be considered in oncolytic viral treatment as an interfering factor.