Comparative protein profiling of B16 mouse melanoma cells susceptible and non-susceptible to alphavirus infection: Effect of the tumor microenvironment

Abstract

Alphavirus vectors are promising tools for cancer treatment. However, relevant entry mechanisms and interactions with host cells are still not clearly understood. The first step toward a more effective therapy is the identification of novel intracellular alterations that could be associated with cancer aggressiveness and could affect the therapeutic potential of these vectors. In this study, we observed that alphaviruses efficiently infected B16 mouse melanoma tumors/tumor cells in vivo, whereas their transduction efficiency in B16 cells under in vitro conditions was blocked. Therefore, we further aimed to understand the mechanisms pertaining to the differential transduction efficacy of alphaviruses in B16 tumor cells under varying growth conditions. We hypothesized that the tumor microenvironment might alter gene expression in B16 cells, leading to an up-regulation of the expression of virus-binding receptors or factors associated with virus entry and replication. To test our hypothesis, we performed a proteomics analysis of B16 cells cultured in vitro and of B16 cells isolated from tumors, and we identified 277 differentially regulated proteins. A further in-depth analysis to identify the biological and molecular functions of the detected proteins revealed a set of candidate genes that could affect virus infectivity. Importantly, we observed a decrease in the expression of interferon a (IFN-a) in tumor-isolated cells that resulted in the suppression of several IFN-regulated genes, thereby abrogating host cell antiviral defense. Additionally, differences in the expression of genes that regulate cytoskeletal organization caused significant alterations in cell membrane elasticity. Taken together, our findings demonstrated favorable intracellular conditions for alphavirus transduction/replication that occurred during tumor transformation. These results pave the way for optimizing the development of strategies for the application of alphaviral vectors as a potent cancer therapy.

Styrylpyridinium Derivatives for Fluorescent Cell Imaging

“…SP compound 6e was selected for fluorescent cell imaging analysis. First, the compound was used to label the BHK-21 cells that are widely used in molecular biology studies [ 59 , 60 , 61 ]. Commercially available CellTracker™ Deep Red dye (Invitrogen) was used as a control because it has a similar emission range (ex/em: 630/660).…”

Pulsed-Focused Ultrasound Slows B16 Melanoma and 4T1 Breast Tumor Growth through Differential Tumor Microenvironmental Changes

“…Nevertheless, it is increasingly evident that the efficacy of immunomodulatory strategies depends on the presence of a baseline immune response [ 15 ]. Thus, many approaches may not be effective, primarily due to the immunosuppressive TIME preventing efficient T cell infiltration and may require additional therapeutic interventions to amplify the immune threshold to result in a more robust therapeutic response [ 53 , 54 , 55 , 56 ]. Compared to other therapies, non-ablative pFUS modulates the TIME without thermal damage and results in dynamic changes to immune cell populations in the regional LN and Sp that were different from the targeted tumors [ 25 , 26 ].…”

The Impact of Focused Ultrasound in Two Tumor Models: Temporal Alterations in the Natural History on Tumor Microenvironment and Immune Cell Response

“…Several CCTFs can demonstrate stimulatory or inhibitory effects on tumor development and progression depending on immune-suppressive or anti-tumor molecular profiles within the TME. Moreover, tumors originating from various organs are likely to contain contributions of cold and hot phenotypic zones, which might be influenced by external physical stimuli in divergent or similar patterns [48][49][50].…”