Modulating tumoral exosomes and fibroblast phenotype using nanoliposomes augments cancer immunotherapy

Stimuli-responsive polymer-dasatinib prodrug to reprogram cancer-associated fibroblasts for boosted immunotherapy

The barriers from cancer-associated fibroblasts (CAFs) have diminished the clinical efficacy of immunotherapy for triple-negative breast cancer (TNBC). The obstacles from CAFs often result in poor drug penetration, constrained cytotoxic T lymphocyte infiltration, and an immunosuppressive microenvironment. Herein, chondroitin sulfate (CS) was engineered to conjugate dasatinib (DAS), a tyrosine kinase inhibitor, via the cathepsin B (CTSB)-responsive GFLG linker to produce CS-GFLG-DAS (CGD), which could be employed to reverse the CAF phenotype and regulate the biosynthesis of extracellular matrix (ECM), thus enhancing the efficacy of immune checkpoint blockade (ICB) therapy. Upon reaching the tumor site, DAS released from CGD in response to overexpressed CTSB in the tumor microenvironment could transform CAFs into a quiescent state instead of killing them to prevent CAFs from producing abundant ECM, thereby promoting deep penetration of CGD to effectively kill tumor cells. In addition, ECM remodeling facilitated tumor infiltration of cytotoxic T lymphocytes, synergistically enhancing the anti-PD-1 efficacy in the 4T1 tumor-bearing mice. In summary, this prodrug enhanced deep drug penetration and therapeutic sensitivity of anti-PD-1 by regulating CAFs, providing new insights into optimizing immunotherapy in treating fibrotic tumors via nanomedicine.

Extracellular vesicle-mediated crosstalk in tumor microenvironment dominates tumor fate

The tumor microenvironment (TME) is a complex and heterogeneous system containing various cells cooperating and competing with each other. Extracellular vesicles (EVs) differing in form and content are important intercellular communication mediators in the TME. Previous studies have focused on the cargoes within EVs rather than on the donors from which they originate and the recipient cells that exert their effects. Therefore, we provide here a detailed overview of the important roles of EVs in shaping tumor fate, highlighting their various mechanisms of intercellular dialog within the TME. We evaluate recent advances and also raise unresolved challenges to provide new ideas for clinical treatment strategies using EVs.

Exosomes derived from colorectal cancer cells suppress B-cell mediated anti-tumor immunity

Exosomes derived from cancer cells significantly influence the tumor immune microenvironment and can limit the efficacy of immunotherapy. However, the impact of exosomes on B cell-dependent anti-tumor immunity remains poorly understood. Here, we demonstrate that exosomes secreted by MC38 (MC38-Exos), a murine colorectal cancer cell line, induce B cells to adopt immunosuppressive phenotypes. MC38-Exos inhibits B cell proliferation and survival. Additionally, MC38-Exos induce B cells to acquire characteristics of regulatory B cells, including the upregulation of IL-10 and TGF-β. Finally, B cells treated with MC38-Exos impair the functional efficacy of CD8+ T cells. Transcriptome analysis reveals that MC38-Exos markedly suppresses gene pathways associated with B cell receptor (BCR) signaling, as well as antigen processing and presentation in B cells, but up-regulates genes involving apoptosis pathway. Mechanistically, NF-κB pathway was enriched in KEGG analysis, and was validated by western blot. Finally, inhibition of MC38-Exo in vivo activates B-cell mediated anti-tumor immunity. Thus, MC38-Exo has a profound effect of transcriptome of B cells and attenuates B cell-dependent anti-tumor immunity, supporting the rationale for targeted exosome therapy in human colorectal cancer.

A Comprehensive Pan-cancer Analysis Identified that TRIB3 was Associated with Immune Cell Infiltration and Poor Prognosis

BACKGROUND

Previous studies have demonstrated that TRIB3 plays a carcinogenic role in tumor progression. However, the exploration of TRIB3 at the pan-cancer level has not been reported.

AIMS

This study aimed to conduct a comprehensive pan-cancer analysis of TRIB3.

OBJECTIVES

We explored the expression pattern and functional mechanism of TRIB3 on the basis of multiple databases.

METHODS

We first explored the expression level of TRIB3 in the TCGA database. Then, the receiver operation characteristic curve (ROC), Kaplan-Meier plotter, and Cox regression were used to estimate the diagnostic and prognostic value of TRIB3, respectively. We also explored the relationship between TRIB3 and the infiltration of tumor immune cells, as well as the expression of immune checkpoint molecules. Gene enrichment and protein interaction network analysis were carried out to identify possible carcinogenic molecular mechanisms and functional pathways. Finally, we compared the non-promoter region methylation of TRIB3 in normal and tumor tissues and explored potential systems with unique functions in TRIB3-mediated tumorigenesis.

RESULTS

The expression level of TRIB3 was elevated in multiple tumor types, and the high expression of TRIB3 was associated with poor prognosis. TRIB3 had a higher frequency of genetic changes in several tumors and showed varying trends in TRIB3 methylation levels. Additionally, high expression of TRIB3 was also associated with infiltration of cancer-related fibroblasts and different types of immune cells and was positively correlated with the expression of immune checkpoint molecules. Furthermore, gene enrichment analysis suggested that TRIB3 may play a role in the malignant progression of cancer by participating in protein post-translational modifications and activating transcription initiation factors.

CONCLUSION

Our pan-cancer analysis provided the potential carcinogenic role of TRIB3 in tumors and verified a promising target for clinical immune treatment.

Sonocatalysis Regulates Tumor Autophagy for Enhanced Immunotherapy

Immunotherapy stands as a groundbreaking strategy for cancer treatment, due to its ability to precisely and safely detect and eradicate tumors. However, the efficacy of immunotherapy is often limited by tumor autophagy, a natural defense mechanism that tumors exploit to resist immune attacks. Herein, we introduce a spatiotemporally controlled method to modulate tumor autophagy via sonocatalysis, aiming to improve immunotherapeutic outcomes. Specifically, we synthesized a tumor-targeting nanocatalyst based on a semiconductor heterojunction composed of Barium Titanate (BTO), Black Phosphorus (BP) integrated with Hyaluronic Acid (HA), referred to as BTO/BP-HA. Compared to traditional catalysts, the heterojunction structure enhances energy band bending and rapid electron-hole separation under ultrasonic stimulation, splitting water to generate H2. This promotes tumor cell apoptosis by inhibiting mitochondrial respiration and induces immunogenic cell death, triggering immune responses to eliminate tumor cells. However, the concurrent activation of autophagy mitigates the cytotoxic effectiveness of nanocatalysts. Within the nanocatalyst, BP undergoes lysosomal degradation to generate PO43-, which subsequently interacts with H+ to generate a conjugated acidic anion, increasing the lysosomal pH. This research ingeniously combines sonocatalysis with tumor autophagy, disrupting the activity of acidic hydrolases to inhibit autophagy, thereby enhancing the immune response and improving the effectiveness of immunotherapy.

CD8+ T cell-based cancer immunotherapy

The immune system in humans is a defense department against both exogenous and endogenous hazards, where CD8+ T cells play a crucial role in opposing pathological threats. Various immunotherapies based on CD8+ T cells have emerged in recent decades, showing their promising results in treating intractable diseases. However, in the fight against the constantly changing and evolving cancers, the formation and function of CD8+ T cells can be challenged by tumors that might train a group of accomplices to resist the T cell killing. As cancer therapy stepped into the era of immunotherapy, understanding the physiological role of CD8+ T cells, studying the machinery of tumor immune escape, and thereby formulating different therapeutic strategies become the imperative missions for clinical and translational researchers to fulfill. After brief basics of CD8+ T cell-based biology is covered, this review delineates the mechanisms of tumor immune escape and discusses different cancer immunotherapy regimens with their own advantages and setbacks, embracing challenges and perspectives in near future.