DNA Nanostructures: Advancing Cancer Immunotherapy.

Cancer immunotherapy is a groundbreaking medical revolution and a paradigm shift from traditional cancer treatments, harnessing the power of the immune system to target and destroy cancer cells. In recent years, DNA nanostructures have emerged as prominent players in cancer immunotherapy, exhibiting immense potential due to their controllable structure, surface addressability, and biocompatibility. This review provides an overview of the various applications of DNA nanostructures, including scaffolded DNA, DNA hydrogels, tetrahedral DNA nanostructures, DNA origami, spherical nucleic acids, and other DNA-based nanostructures in cancer immunotherapy. These applications explore their roles in vaccine development, immune checkpoint blockade therapies, adoptive cellular therapies, and immune-combination therapies. Through rational design and optimization, DNA nanostructures significantly bolster the immunogenicity of the tumor microenvironment by facilitating antigen presentation, T-cell activation, tumor infiltration, and precise immune-mediated tumor killing. The integration of DNA nanostructures with cancer therapies ushers in a new era of cancer immunotherapy, offering renewed hope and strength in the battle against this formidable foe of human health.

Five-Year Outcome and Safety in Patients Treated With Immune Checkpoint Blockade Therapies for Urothelial Carcinoma: Experience From Real-World Clinical Practice.

BACKGROUND: In this study, we report real-world results from the 5-year follow-up data of urothelial carcinoma patients treated with immune checkpoint blockade therapies (ICTs). PATIENTS AND METHODS: Metastatic urothelial carcinoma patients treated with at least one course of ICT were included in the study. The primary endpoint was overall response rate (ORR), and secondary endpoints were overall survival (OS), progression-free survival (PFS), duration of treatment with ICT, and safety. Median follow-up, PFS, and OS were estimated by using the Kaplan-Meier method. RESULTS: Data of 201 eligible patients were analyzed. The median age of the patients was 66 (37-86) years, and 156 (84.3%) were male. The majority of patients (94.6%) had Eastern Cooperative Oncology Group (ECOG) PS scores of 0 to 1 and primary tumor in the bladder was predominant (87.5%). The median follow-up time was 54 (1.15-65) months. The rate of complete response (CR) to ICT, partial response (PR) rate, and ORR were 10.4% (n = 21), 22.4% (n = 45), and 32.4% (n = 66), respectively. The median duration of response (DOR) was 34.8 months (95% confidence interval [CI], 29.2-42.1). Of the 66 patients who responded to treatment, 28 (42%) had an ongoing response at the time of the analysis. Median PFS and OS were 3.8 (2.6-5.8) months and 9.4 (7.4-11.4) months, respectively. The 5-year PFS and OS rates were 9.8% and 12.8%, respectively. Fifty-eight percent of patients experienced a treatment-related adverse event of any grade, and 33 (16.4%) patients had a grade 3 to 4 adverse event. CONCLUSION: This 5-year analysis of real-world data confirms the durable response and long-term survival with ICT in metastatic urothelial carcinoma patients.

PDL1-positive exosomes suppress antitumor immunity by inducing tumor-specific CD8+ T cell exhaustion during metastasis.

Metastasis is the main cause of death in individuals with cancer. Immune checkpoint blockade (ICB) can potentially reverse CD8+ cytotoxic T lymphocytes (CTLs) dysfunction, leading to significant remission in multiple cancers. However, the mechanism underlying the development of CTL exhaustion during metastatic progression remains unclear. Here, we established an experimental pulmonary metastasis model with melanoma cells and discovered a critical role for melanoma-released exosomes in metastasis. Using genetic knockdown of nSMase2 and Rab27a, 2 key enzymes for exosome secretion, we showed that high levels of effector-like tumor-specific CD8+ T cells with transitory exhaustion, instead of terminal exhaustion, were observed in mice without exosomes; these cells showed limited inhibitory receptors and strong proliferation and cytotoxicity. Mechanistically, the immunosuppression of exosomes depends on exogenous PD-L1, which can be largely rescued by pretreatment with antibody blockade. Notably, we also found that exosomal PD-L1 acts as a promising predictive biomarker for ICB therapies during metastasis. Together, our findings suggest that exosomal PD-L1 may be a potential immunotherapy target, suggesting a new curative therapy for tumor metastasis.