The VISTA/VSIG3/PSGL-1 axis: crosstalk between immune effector cells and cancer cells in invasive ductal breast carcinoma

Impact of cannabinoids on cancer outcomes in patients receiving immune checkpoint inhibitor immunotherapy

Cannabinoids relieve pain, nausea, anorexia and anxiety, and improve quality of life in several cancer patients. The immunotherapy with checkpoint inhibitors (ICIs), although very successful in a subset of patients, is accompanied by moderate to severe immune-related adverse events (ir-AE) that often necessitate its discontinuation. Because of their role in symptomatic relief, cannabinoids have been used in combination with immune checkpoint inhibitor (ICI) immunotherapy. A few studies strongly suggest that the use of medicinal cannabis in cancer patients attenuates many of the ir-AE associated with the use of ICI immunotherapy and increase its tolerability. However, no significant beneficial effects on overall survival, progression free survival or cancer relapses were observed; rather, some of the studies noted adverse effects of concurrent administration of cannabinoids with ICI immunotherapy on the clinical benefits of the latter. Because of cannabinoids' well documented immunosuppressive effects mediated through the cannabinoid recptor-2 (CB2), we propose considering this receptor as an inhibitory immune checkpoint per se. A simultaneous neutralization of CB2, concurrent with cannabinoid treatment, may lead to better clinical outcomes in cancer patients receiving ICI immunotherapy. In this regard, cannabinoids such as cannabidiol (CBD) and cannabigerol (CBG), with little agonism for CB2, may be better therapeutic choices. Additional strategies e.g., the use of monoacylglycerol lipase (MAGL) inhibitors that degrade some endocannabinoids as well as lipogenesis and formation of lipid bilayers in cancer cells may also be explored. Future studies should take into consideration gut microbiota, CYP450 polymorphism and haplotypes, cannabinoid-drug interactions as well as genetic and somatic variations occurring in the cannabinoid receptors and their signaling pathways in cancer cells for personalized cannabis-based therapies in cancer patients receiving ICIs. This may lead to rational knowledge-based regimens tailored to individual cancer patients.

Tumor Microenvironment Drives the Cross-Talk Between Co-Stimulatory and Inhibitory Molecules in Tumor-Infiltrating Lymphocytes: Implications for Optimizing Immunotherapy Outcomes

This review explores some of the complex mechanisms underlying antitumor T-cell response, with a specific focus on the balance and cross-talk between selected co-stimulatory and inhibitory pathways. The tumor microenvironment (TME) fosters both T-cell activation and exhaustion, a dual role influenced by the local presence of inhibitory immune checkpoints (ICs), which are exploited by cancer cells to evade immune surveillance. Recent advancements in IC blockade (ICB) therapies have transformed cancer treatment. However, only a fraction of patients respond favorably, highlighting the need for predictive biomarkers and combination therapies to overcome ICB resistance. A crucial aspect is represented by the complexity of the TME, which encompasses diverse cell types that either enhance or suppress immune responses. This review underscores the importance of identifying the most critical cross-talk between inhibitory and co-stimulatory molecules for developing approaches tailored to patient-specific molecular and immune profiles to maximize the therapeutic efficacy of IC inhibitors and enhance clinical outcomes.

VSIG-3/IGSF11 silencing in A2058 melanoma cells simultaneously suppresses melanoma progression and induces anti-tumoral cytokine profile in human T cells: In silico and in vitro study

VISTA is a newly discovered immune checkpoint whose functional mechanisms have become increasingly important to study due to its brilliant results in cancer immunotherapy. Despite VSIG-3/IGSF11 being identified as an inhibitory ligand for VISTA with potential as a target for cancer immunotherapy, very little is known of its functions. This study aimed to conduct a detailed analysis of VSIG-3/IGSF11 in melanoma, as well as to study the effects of its silencing on melanoma cell line progression and human T cell functions. Online databases were used to investigate VSIG-3/IGSF11 expression, its relationships, and prognostic value in melanoma. Then, the effects of VSIG-3/IGSF11 silencing on proliferation, migration, cell cycle arrest, and apoptosis in A2058 melanoma cells were assessed using MTT, colony formation, wound healing, cell cycle, and Annexin-V FITC/PI assays, respectively. Finally, A2058 cells transfected with VSIG-3/IGSF11 siRNA were co-cultured with human T cells, and the expression levels of T cell cytokines were evaluated using qRT-PCR. VSIG-3/IGSF11 expression was significantly increased in melanoma patients and cell lines; however, no correlation was found between VSIG-3/IGSF11 expression levels and clinicopathological characteristics, survival, or immune cell infiltration. Following VSIG-3/IGSF11 silencing in A2058 cells, viability, proliferation, and migration rates were decreased, while apoptosis was increased. T cells co-cultured with VSIG-3/IGSF11 siRNA-transfected A2058 cells exhibited increased expression levels of IFN-γ and IL-12 and decreased expression levels of IL-10, TGF-β, and TNF-α. The inhibitory effect of VSIG-3/IGSF11 silencing on A2058 melanoma cell progression, along with the alteration of T cell cytokines towards a pro-inflammatory phenotype, suggests that VSIG-3/IGSF11 is primarily involved in melanoma progression and modulating immune responses. Therefore, it may be a valuable target for immunotherapy in melanoma patients.