Novel N-amidinopiperidine-based proteasome inhibitor preserves dendritic cell functionality and rescues their Th1-polarizing capacity in Ramos-conditioned tumor environment

A pyroptosis-related lncRNA risk model for the prediction of prognosis and immunotherapy response in head and neck squamous cell carcinoma

Background

Recent research has highlighted pyroptosis as a key factor in cancer progression. This study aims to explore the association between pyroptosis-related signatures and overall survival (OS) in head and neck squamous cell carcinoma (HNSC) and develop a pyroptosis-related long non-coding RNA (lncRNA) risk model to predict prognosis and response to immunotherapy in HNSC.

Methods

We extracted expression data for 18 pyroptosis-related genes and identified lncRNA probes specific to HNSC by using datasets from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Consensus clustering was performed to categorize HNSC patients into distinct subtypes. A six-lncRNA risk score model was constructed through univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses. We evaluated the predictive ability of the lncRNA model for patients' survival and immunotherapy response. Gene expression was evaluated using immunohistochemistry (IHC) and Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR).

Results

Our analysis revealed two distinct pyroptosis-related subtypes in HNSC patients, Cluster A and Cluster B. Notably, patients in Cluster B exhibited significantly poorer overall survival compared to those in Cluster A. Through differential expression analysis, we identified six lncRNAs (AC002331.1, CTA-384D8.35, RP11-291B21.2, AC006262.5, RP1-27K12.2, and RP11-54H7.4) that were differentially expressed between these clusters. A 6-lncRNA risk score model was developed, which successfully stratified patients into high- and low-risk groups with distinct overall survival outcomes. Validation using RT-qPCR confirmed the differential expression of these six lncRNAs in HNSC tumor tissues compared to adjacent normal tissues, we found that the expression of CTA-384D8.35 was significantly increased in the tumor group (t=-6.203, P<0.001). Furthermore, the 6-lncRNA risk score model demonstrated a significant association with patient response to immunotherapy, with the low-risk group exhibiting a higher objective response rate to immune checkpoint blockade (ICB) therapy and longer survival compared to the high-risk group.

Conclusion

Our study underscores the role of pyroptosis signatures in HNSC prognosis and identifies two distinct pyroptosis subtypes with differing survival outcomes. The six-lncRNA risk score model offers a valuable tool for predicting patient prognosis and potential benefits from ICB therapy. These findings highlight the importance of pyroptosis and associated lncRNAs in the tumor microenvironment, paving the way for novel targeted therapies in HNSC.

The Role of Proteasome Inhibitor MG132 in 2,4-Dinitrofluorobenzene-Induced Atopic Dermatitis in NC/Nga Mice

BACKGROUND

Although immunosuppressants for therapy of atopic dermatitis (AD) are still being sought, proteasome inhibitors are also potential candidates for the treatment of AD. Proteasome inhibitors exert various effects by blocking proteasomal degradation and help regulate processes such as apoptosis induction via caspase-9, cell cycle progression via cyclins, NF-κB inactivation via IκB, and downregulation of antigen cross-presentation. The cells targeted by proteasome inhibitors are therefore activated cells undergoing proliferation or differentiation, and antigen-presenting cells carrying out protein degradation.

OBJECTIVES

This study investigated the therapeutic effects and side effects of a proteasome inhibitor, MG132, on the treatment of AD.

METHODS

AD-like disease in NC/Nga mice housed under specific pathogen-free conditions was induced by repeated application of 2,4-dinitrofluorobenzene (DNFB). Disease progression was evaluated by inflammation score, histopathology, and serum IgE level, and the effects of systemic MG132 administration were investigated. The percentages and absolute numbers for each population of Th1, Th2, and Th17 cells in the axillary lymph nodes were analyzed by flow cytometry.

RESULTS

DNFB application increased the expression of a unique major histocompatibility complex class I mutant molecule D/Ldm7 in dendritic cells (DCs), and increased Th1 and Th17 cells in NC/Nga mice. In vivo MG132 administration to NC/Nga mice with DNFB-induced dermatitis reduced Th17 cells but maintained the level of Th1 cells, resulting in the alleviation of dermatitis lesions by decreasing both serum IgE hyperproduction and mast cell migration. To understand the mechanisms maintaining Th1 cell levels following in vivo MG132-administration, we focused on the role of proteasomes regulating D/Ldm7 expression. Interestingly, 20S proteasome activity was higher in NC/Nga DCs than in BALB/c DCs. In vitro MG132 administration partially increased D/Ldm7 expression in a dose-dependent manner during DC maturation, and induced IFN-γ production from autoreactive CD8+ T cells but not from CD4+ T cells following coculturing with D/Ldm7-upregulated DCs.

CONCLUSION

Although MG132 administration temporarily alleviated AD pathogenesis in NC/Nga mice, prolonged MG132 treatment may result in immunopathogenesis leading to chronic AD due to its side effect of maintaining Th1 levels via autoreactive CD8+ T cells.