Immune checkpoint inhibitors (ICI) targeting PD-1/PD-L1 have been approved for the treatment of a variety of cancers. However, the efficacy of antibody-based ICIs could be further improved by mitigating anti-drug antibodies, proteolytic cleavage, and on-target off-tumor toxicity. One strategy for accomplishing this is through the use of extracellular vesicles (EVs), cell derived submicron vesicles with many unique properties. We constructed an engineered MDA-MB-231 cell line for harvesting EVs. This was accomplished by overexpressing a high-affinity variant human PD-1 protein (havPD-1), while simultaneously knocking out intrinsic PD-L1 and beta-2 microglobulin. The engineered havPD-1 EVs reduced PD-L1 overexpressing cancer cell proliferation and induced cellular apoptosis. Moreover, the EVs were shown to efficiently block PD-L1 mediated T cell suppression. Meanwhile antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity were not observed. The havPD-1 EVs treatment resulted in robust anti-tumor activity in both preventative co-implantation and therapeutic xenograft tumor models reconstituted with human T cells. The efficacy of the havPD-1 EVs was shown to be comparable to clinical anti-PD1 monoclonal antibodies. Additionally, loading the havPD-1 EVs with a potent PARP inhibitor was shown to further augment treatment efficacy. In brief, the engineered universal EVs harboring havPD-1 proteins can be used for cancer concurrent immunotherapy and chemotherapy.

Background: Targeted mRNA-lipid nanoparticles (LNP) show great potential for cancer immunotherapy by delivering neoantigen-encoding messages to tumor cells, prompting immune responses against tumors. However, the challenges of inefficient production of targeting ligand-grafted LNPs and the immunogenic effects of polyethylene glycol (PEG) hinder their therapeutic effectiveness.

Introduction: Circulating tumor cells (CTCs) have attracted significant interest as a biomarker for cancer diagnosis. In this study, we judiciously constructed a recombinant MUC1-dependent adenovirus (rAdF35-MUC1) that can selectively replicate and overexpress copepod super green fluorescent proteins (copGFP) in MUC1-positive tumor cells to investigate its role in the detection of CTCs.Methods: We conducted a comparative study between rAdF35-MUC1 and the existing hTERT-dependent adenovirus (rAdF35-hTERT). Breast cancer cell lines and healthy human peripheral blood mononuclear cells (PBMCs) were infected with both viral constructs to evaluate infection efficiency and the incidence of false-positive cells. CTC Model Samples were employed to determine detection rates, and clinical samples from breast cancer patients were analyzed to preliminarily evaluate the efficacy of CTC detection in a clinical context.Results: In preclinical and clinical studies, rAdF35-MUC1 exhibited a significantly high detection efficiency for breast cancer cells, outperforming the existing hTERT-dependent adenovirus (rAdF35-hTERT), especially in detecting CTCs at low quantities. Moreover, rAdF35-MUC1 demonstrated reduced incidence of false positives in healthy PBMCs compared to rAdF35-hTERT.Conclusion: In brief, rAdF35-MUC1 emerges as a potent tool for the sensitive and specific identification of CTCs derived from breast cancer patients, holding clinical translation potential for advancing cancer (early) diagnosis, treatment monitoring, and prognosis.

Background: Studies have shown that nucleotide-binding oligomerization domain (NOD)-like receptors family CARD domain containing 5 (NLRC5) is involved in promoting the transformation and invasion of malignant cancer cells. However, the effects and mechanism of action of NLRC5 in lung adenocarcinoma have yet to be elucidated. The aim of this study was therefore to investigate the effect of NLRC5 expression on the invasion and metastasis of lung adenocarcinoma (LUAD) cells and its mechanisms. Methods: Tumor and tumor-adjacent normal tissues were acquired from LUAD patients admitted to the affiliated Suqian hospital of Xuzhou medical university from June 2017 to December 2019. A549 and H292 cells were transfected with negative siRNA (si-NC) and NLRC5 siRNA (si-NLRC5), respectively. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway agonist 740Y-P was added to cells in the si-NLRC5 group, while cells without any treatment were used as controls. NLRC5 expression was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. In addition, the techniques of cell colony formation, Transwell assay and scratch tests were employed to assess cell viability, invasion, and migration, respectively. The expressions of genes related to epithelial-mesenchymal transition (EMT) and the PI3K/AKT pathway was also evaluated by Western blot. Results: NLRC5 expression in LUAD cell lines and tissues was markedly increased compared to normal human bronchial epithelial (HBE) cells and tumor-adjacent normal tissues (p < 0.05). Knockdown of NLRC5 expression significantly reduced cell viability, invasion and migration, as well as reducing EMT processes and inhibiting activation of the PI3K/AKT pathway (p < 0.05). However, treatment with 740Y-P partially reversed the impact of NLRC5 knockdown in LUAD cells (p < 0.05). Conclusion: NLRC5 stimulates the invasion and metastasis of LUAD cells through activating the PI3K/AKT pathway.