Xiang-Ping Li

Immunotherapy targeting the programmed death ligand-1/programmed cell death protein-1 (PD-L1/PD-1) pathway exhibits limited effectiveness in individuals with recurrent and metastatic nasopharyngeal carcinoma (NPC). Recent studies have noted that hypoxia within the tumor microenvironment (TME) triggers intricate interplay, termed “hypoxia-induced exosome-mediated communication”, between cancer cells and various immune cells. However, the role of hypoxia in modulating the immunosuppressive environment and its implications on the efficacy of immunotherapy in NPC remains poorly understood. In this study, we found hypoxia inducible factor-1 (HIF-1α) was positively associated with increased PD-L1 levels and decreased CD8⁺ T cell infiltration, and correlated with a poor prognosis. Mechanistically, we demonstrated that hypoxia regulated the expression of PD-L1 in NPC cells and their exosomes by activating the binding of HIF-1α to the PD-L1 promoter. Meanwhile, using in vitro approaches, we found that macrophages could upregulate their PD-L1 expression through the phagocytosis of exosomal PD-L1 derived from NPC cells. Furthermore, we confirmed that PD-L1⁺ macrophages could induce CD8⁺ T cell exhaustion and reduce their proliferation. In conclusion, our study revealed that hypoxia (via HIF-1α) upregulated the expression of PD-L1 in exosomes derived from NPC cells, while macrophages induce the suppression of CD8⁺ T cells by phagocytosis of exosomal PD-L1. Targeting the PD-L1⁺ macrophages could potentially serve as a promising approach to augment the effectiveness of immune checkpoint blockade in NPC.

The zinc finger protein 32 (ZNF32) has been associated with high expression in various cancers, underscoring its significant function in both cancer biology and immune response. To further elucidate the biological role of ZNF32 and identify potential immunotherapy targets in cancer, we conducted an in-depth analysis of ZNF32. We comprehensively investigated the expression of ZNF32 across tumors using diverse databases, including TCGA, CCLE, TIMER2.0, KM-Plotter, cBioPortal, ImmuCellAI. We investigated correlations between ZNF32 expression and various factors such as prognosis, immune infiltration, immunotherapy, DNA methylation, and biological functions. Furthermore, we performed in vitro research to validate the significance of ZNF32 in head and neck cancer (HNSC). Our study revealed that ZNF32 was high in various types of cancer, including ACC, BRCA, and others, indicating its important potential as a prognostic biomarker. Significant changes in CNA and DNA methylation were associated with high ZNF32 expression. ZNF32 was notably linked to various immune characteristics, including immune cell infiltration, MSI, TMB and immune checkpoint gene expression, indicating its potential in informing immunotherapy approaches. Interestingly, in FaDu and CAL27 cell lines, the group with elevated ZNF32 expression exhibited increased levels of immune checkpoint markers, such as CTLA-4 and PD-L1. Overexpression of ZNF32 significantly enhanced proliferation and migration in FaDu and CAL27 cell lines, as demonstrated through CCK-8 assays, colony formation, flow cytometry, Transwell migration, and Boyden invasion assays. Our in vitro experiments confirmed that ZNF32 promotes malignant behavior by driving HNSC cell proliferation and migration. These results imply that ZNF32 might be a promising target for tumor prognosis and immunotherapy. Our results highlight the important role of ZNF32 in tumorigenesis and provide novel perspectives for potential cancer treatment strategies.

Original Article Laryngeal contact granuloma after radiotherapy in patients with nasopharyngeal carcinoma: a case series Ting-Ting Mo, Huai-Hong Chen, Xue-Qiong Huang, Xiao-Yan Han, Fang-Fang Zeng, Xiang-Ping Li

BACKGROUND: Sudden sensorineural hearing loss is a common disease with several etiologic hypotheses, such as infection, vascular occlusion, inflammation, oxidative stress, etc. Studies have reported that the concentration of cell-free DNA in plasma will elevate in these situations. Former studies have reported that the whole-genome sequencing of cell-free DNA has high accuracy and sensitivity in inferring gene expressions. In this study, we plan to use the whole-genome sequencing of cell-free DNA to uncover novel prognostic factors of sudden sensorineural hearing loss and provide new insight into the clinical application of cell-free DNA. METHODS: In this study, 84 sudden sensorineural hearing loss patients (47 in recovery group and 37 in no-recovery group) were enrolled. After whole-genome sequencing of the cell-free DNA, the protein–protein interaction network was constructed using the differentially expressed genes. Multinomial logistics regression analysis was used to analyze the prognostic factors of hearing improvement. RESULTS: In this study, we found distinct patterns of expressed and unexpressed genes in cell-free DNA sequence read depth coverage in sudden sensorineural hearing loss patients. The top centrality hub genes IGF1, NOTCH1, APOE, FAM3C, RPS6KB1, and RELB were identified from the protein–protein interaction network. Multinomial logistics regression analysis demonstrated that the coverage patterns of 3 key differentially expressed genes (NOTCH1, APOE, and RELB) are significantly different in sudden sensorineural hearing loss with and without hearing recovery. CONCLUSION: The cell-free DNA could have more applications in diverse diseases, and the coverage patterns of 3 differentially expressed genes (NOTCH1, APOE, and RELB) are independent prognostic factors of sudden sensorineural hearing loss. Their expression levels may play a critical role in the hearing improvement of sudden sensorineural hearing loss patients. Cite this article as: Yang A, Liu S, Yang X, et al. Uncovering novel prognostic factors of sudden sensorineural hearing loss by whole-genome sequencing of cell-free DNA. J Int Adv Otol. 2022;18(6):459-464.

Immunotherapy targeting programmed death ligand-1/programmed cell death protein-1 (PD-L1/PD-1) has achieved great success in multiple cancers, but only a small subset of patients showed clinical responses. Recent evidences have shown that post-translational modification of PD-L1 protein could regulate its protein stability and interaction with cognate receptor PD-1, thereby affecting anticancer immunotherapy in several solid tumors. However, the molecular mechanisms underlying how PD-1/PD-L1 expression is regulated still remain unclear in nasopharyngeal carcinoma (NPC). Here, we found N-glycosylation of PD-L1 in NPC cells and tissues. Mechanistically, we showed that STT3A transferred N-linked glycans to PD-L1, and TGF-β1 could positively regulate STT3A expression through activating c-Jun to bind to STT3A promoter. Functional assays showed that inhibition of TGF-β1 resulted in a decrease of glycosylated PD-L1 and enhanced cytotoxic T-cell function against NPC cells. Analysis of clinical specimens revealed that the expression of STT3A was positively correlated with TGF-β1 and c-Jun, and high STT3A expression was positively correlated with a more advanced clinical stage. Altogether, TGF-β1 activated c-Jun/STT3A signaling pathway to promote N-glycosylation of PD-L1, thus further facilitating immune evasion and reducing the efficacy of cancer immunotherapy. As such, all these data suggested that targeting TGF-β1 pathway might be a promising approach to enhance immune checkpoint blockade, and simultaneous blockade of PD-L1 and TGF-β1 pathways might elicit potent and superior antitumor activity relative to monotherapies.

Objective: We aimed to develop a nomogram to predict cancer-specific survival (CSS) in patients with hypopharyngeal squamous cell carcinoma (HSCC) treated with primary surgery to provide more accurate risk stratification for patients. Methods: We retrospectively collected data of 1144 eligible patients with HSCC from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Patients were randomly divided into training and validation groups (ratio 6:4) and we used univariate and multivariate Cox analysis. We developed and validated a nomogram using calibration plots and time-dependent receiver operating characteristic, Kaplan–Meier, and decision curves. Results: Age; marital status; T, N, and M stage; and postoperative adjuvant therapy were independent factors associated with CSS, which were included in the nomogram. The nomogram’s C-index was 0.705 to 0.723 in the training group and 0.681 to 0.736 in the validation group, which were significantly higher than conventional American Joint Committee on Cancer (AJCC) staging. Calibration curves showed good agreement between prediction and observation in both groups. Kaplan–Meier and decision curves suggested the nomogram had better risk stratification and net benefit than conventional AJCC staging. Conclusions: We established a nomogram that was superior to conventional AJCC staging in predicting CSS for HSCC.