TP53/mTORC1-mediated bidirectional regulation of PD-L1 modulates immune evasion in hepatocellular carcinoma

Cancer cell-specific PD-L1 expression is a predictor of poor outcome in patients with locally advanced oral cavity squamous cell carcinoma

BACKGROUND

Locally advanced oral cavity squamous cell carcinoma (OCSCC) presents a significant clinical challenge despite being partially responsive to standard treatment modalities. This study investigates the prognostic implications of programmed death-ligand 1 (PD-L1) expression in these tumors, focusing on its association with treatment outcomes and the immune microenvironment.

METHODS

We assessed tumor-infiltrating lymphocytes (TILs) in 132 patients with OCSCC to evaluate their impact on survival. Multiplex immunohistochemistry staining for CD3, CD68, CD11c, PD-L1, and P40 was used to explore correlations with clinical outcomes in patients with early-stage (n=22) and locally advanced (n=36) OCSCC. These initial findings were validated through differential gene expression analysis, gene set enrichment, and immune cell deconvolution in a The Cancer Genome Atlas cohort of 163 locally advanced OCSCC tumors. Additionally, single-cell RNA sequencing (scRNA-seq) on a smaller cohort (n=10) further characterized the PD-L1hi or PD-L1lo cancer cells in these tumors.

RESULTS

Elevated PD-L1 expression was associated with poor outcomes in patients with locally advanced OCSCC undergoing standard adjuvant therapy, irrespective of "hot" or "cold" classification based on TILs assessment. PD-L1hi tumors exhibited an active immune response phenotype, enriched with M1 macrophages, CD8+ T cells and T regulatory cells in the tumor microenvironment. Notably, the negative impact of PD-L1 expression on outcomes was primarily attributed to its expression by cancer cells, rather than immune cells. Furthermore, scRNA-seq revealed that immune interactions were not essential for PD-L1 upregulation in cancer cells, instead, complex regulatory networks were involved. Additionally, PD-L1lo locally advanced tumors exhibited more complex pathway enrichment and diverse T-cell populations compared with those in the early-stage.

CONCLUSION

Our findings underscore the prognostic significance of PD-L1 expression in locally advanced OCSCC, and unveil the complex interplay between PD-L1 expression, immune responses, and molecular pathways in the tumor microenvironment. This study provides insights that may inform future therapeutic strategies, including the possibility of tailored immunotherapeutic approaches for patients with PD-L1hi locally advanced OCSCC.

Progress of immune checkpoint inhibitors in the treatment of advanced hepatocellular carcinoma

Among primary liver cancers, hepatocellular carcinoma is the most common pathological type. Its onset is insidious, and most patients have no obvious discomfort in the early stage, so it is found late, and the opportunity for surgical radical treatment is lost, resulting in a poor prognosis. With the introduction of molecular-targeted drugs represented by sorafenib, patients with middle- and late-stage liver cancer have regained the light of day. However, their therapeutic efficacy is relatively low due to the limited target of drug action, toxic side effects, and other reasons. At this time, the emergence of immunotherapy represented by immune checkpoint inhibitors (ICIs) well breaks this embarrassing situation, which mainly achieves the anti-tumor purpose by improving the tumor immune microenvironment. Currently, ICI monotherapy, as well as combination therapy, has been widely used in the clinic, further prolonging the survival of patients with advanced hepatocellular carcinoma. This article reviews the development of monotherapy and combination therapy for ICIs in advanced hepatocellular carcinoma and the latest research progress.

Immune landscape of hepatocellular carcinoma: The central role of TP53-inducible glycolysis and apoptosis regulator

Objective

This study aims to address the substantive issue of lacking reliable prognostic biomarkers in hepatocellular carcinoma (HCC) by investigating the relationship between TP53-inducible glycolysis and apoptosis regulator (TIGAR) and HCC prognosis using The Cancer Genome Atlas database.

Methods

(1) Integrated statistical analyses, including logistic regression, Wilcoxon signed-rank test, and Kruskal-Wallis test, were conducted to explore the association between TIGAR expression and clinical-pathological features of HCC. (2) The Kaplan-Meier method combined with univariate and multivariate Cox regression models underscored TIGAR as a prognostic factor in HCC. (3) Gene set enrichment analysis (GSEA) revealed key pathways associated with TIGAR, while single-sample gene set enrichment analysis (ssGSEA) determined its relevance to cancer immune infiltration.

Results

(1) Elevated TIGAR expression was significantly correlated with decreased survival outcomes in HCC patients. (2) GSEA highlighted the significant link between TIGAR and humoral immunity. (3) ssGSEA revealed a positive correlation between TIGAR expression and infiltration of Th1 and Th2 cells and a negative correlation with Th17 cell infiltration.

Conclusion

TIGAR, as a potential prognostic biomarker for HCC, holds significant value in immune infiltration. Understanding the role of TIGAR could contribute to improved prognostic predictions and personalized treatment strategies for HCC patients.

Porphyromonas gingivalis, a bridge between oral health and immune evasion in gastric cancer

Porphyromonas gingivalis (P. gingivalis) is a gram-negative oral pathogen associated with chronic periodontitis. Previous studies have linked poor oral health and periodontitis with oral cancer. Severe cases of periodontal disease can result in advanced periodontitis, leading to tissue degradation, tooth loss, and may also correlate with higher gastric cancer (GC) risk. In fact, tooth loss is associated with an elevated risk of cancer. However, the clinical evidence for this association remains inconclusive. Periodontitis is also characterized by chronic inflammation and upregulation of members of the Programmed Death 1/PD1 Ligand 1 (PD1/PDL1) axis that leads to an immunosuppressive state. Given that chronic inflammation and immunosuppression are conditions that facilitate cancer progression and carcinogenesis, we hypothesize that oral P. gingivalis and/or its virulence factors serve as a mechanistic link between oral health and gastric carcinogenesis/GC progression. We also discuss the potential impact of P. gingivalis' virulence factors (gingipains, lipopolysaccharide (LPS), and fimbriae) on inflammation and the response to immune checkpoint inhibitors in GC which are part of the current standard of care for advanced stage patients.

FOXA1-Driven pathways exacerbate Radiotherapy-Induced kidney injury in colorectal cancer

OBJECTIVE

This study aimed to investigate the role of FOXA1 in acute kidney injury (AKI) induced by radiotherapy in colorectal cancer. Although FOXA1 is known to be aberrantly expressed in malignant tumors, its contribution to AKI remains unclear. This study aimed to explore the involvement of FOXA1 in AKI induced by radiotherapy in colorectal cancer and its influence on the regulation of downstream target genes.

METHODS

Firstly, a transcriptome analysis was performed on mice to establish a radiation-induced AKI model, and qPCR was used to determine the expression of FOXA1 in renal cell injury models induced by X-ray irradiation. Additionally, FOXA1 was silenced using lentiviral vectors to investigate its effects on the apoptosis of mice with radiation-induced AKI and HK-2 cells. Next, bioinformatics analysis and various experimental validation methods such as ChIP assays, co-immunoprecipitation, and dual-luciferase reporter assays were employed to explore the relationship between FOXA1 and the downstream regulatory factors ITCH promoter and the ubiquitin ligase-degradable TXNIP. Finally, lentiviral overexpression or knockout techniques were used to investigate the impact of the FOXA1/ITCH/TXNIP axis on oxidative stress and the activation of inflammatory body NLRP3.

RESULTS

This study revealed that FOXA1 was significantly upregulated in the renal tissues of mice with radiation-induced AKI and in the injured HK-2 cells. Furthermore, in vitro cell experiments and animal experiments demonstrated that FOXA1 suppressed the transcription of the E3 ubiquitin ligase ITCH, thereby promoting apoptosis of renal tubular cells and causing renal tissue damage. Further in vivo animal experiments confirmed that TXNIP, a protein degraded by ITCH ubiquitination, could inhibit oxidative stress and the activation of NLRP3 inflammasome in the AKI mouse model.

CONCLUSION

FOXA1 enhances oxidative stress, cell apoptosis, and NLRP3 inflammasome activation by regulating the ITCH/TXNIP axis, thereby exacerbating radiotherapy-induced AKI.

Case report: The first account of undifferentiated sarcoma with epithelioid features originating in the pleura

Undifferentiated epithelioid sarcoma (USEF) is a rare subtype of undifferentiated soft tissue sarcoma that presents unique challenges in clinical diagnosis and treatment. Here, we report a case of USEF occurring in the pleura of a 51-year-old man for the first time. Thoracoscopic examination revealed widespread nodular changes, and pathological analysis confirmed the presence of numerous epithelioid atypical cells. Immunohistochemical (IHC) analysis demonstrated an undifferentiated phenotype with distinct characteristics: epithelial membrane antigen (foci +), vimentin (+), Ki-67 (+70% +), TTF-1 (+), P53 (mutant type +90%), INI-1 (+), and CK5/6 (small foci +). Immunohistochemical examination of the tumor showed that the tumor was an undifferentiated epithelioid sarcoma. High-throughput DNA sequencing revealed pivotal mutations, including a nonsense mutation in the NF1 gene (c.641A > G(p.H214R)). and critical TP53 missense mutation (c.641A > G(p.H214R)). This TP53 mutation, with a tumor mutation burden of 16.5 Muts/Mb, signifies a high level of genomic instability, likely contributing to the rapid progression and aggressiveness of the disease. Detection of the TP53 mutation provides essential insights, indicating the disease's rapid progression and highlighting the potential for targeted therapies. Although the patient's disease progressed extremely rapidly and he tragically died within a week, we discussed the results of IHC and DNA sequencing in detail and discussed his possible treatment options. Insights gained from this case will be critical in shaping future diagnostic and therapeutic paradigms for USEF, particularly in the context of TP53 mutations.

The association of genomic alterations with PD-L1 expression in Chinese patients with EGFR/ALK wild-type lung adenocarcinoma and potential predictive value of Hippo pathway mutations to immunotherapy

BACKGROUND

The study focuses on PD-L1 expression as an essential biomarker for gauging the response of EGFR/ALK wild-type NSCLC patients to FDA-approved immune checkpoint inhibitors (ICIs). It aims to explore clinical, molecular, and immune microenvironment characteristics associated with PD-L1 expression in EGFR/ALK wild-type lung adenocarcinoma patients eligible for ICI therapy.

METHODS

In this retrospective study, tumor samples from 359 Chinese EGFR/ALK wild-type lung adenocarcinoma patients underwent comprehensive evaluations for PD-L1 expression and NGS-targeted sequencing. The investigation encompassed the analysis and comparison of clinical traits, gene mutations, pathways, and immune signatures between two groups categorized by PD-L1 status: negative (TPS < 1%) and positive (TPS ≥ 1%). Additionally, the study explored the link between genomic changes and outcomes following immunotherapy.

RESULTS

High tumor mutational burden correlated significantly with PD-L1 positivity in patients with EGFR/ALK wild-type lung adenocarcinoma. Gene alterations, including TP53, KRAS, and others, were more pronounced in the PD-L1 positive group. Pathway analysis highlighted higher frequencies of alterations in pathways like RTK/RAS, p53, and Hippo in PD-L1-positive patients. The Hippo pathway's relevance was confirmed in separate immunotherapy cohorts, associated with better outcomes. In terms of immune cell infiltration, Hippo mutants exhibited higher levels of CD68+ PD-L1+ macrophages, CD8+ T cells, and CD8+ PD-1- T cells.

CONCLUSIONS

This study offers insights into genomic features of Chinese EGFR/ALK wild-type lung adenocarcinoma patients based on PD-L1 expression. Notably, Hippo pathway alterations were linked to improved immunotherapy outcomes. These findings suggest connections between the Hippo pathway and PD-L1 expression, warranting further clinical and functional investigations. The research advances our understanding of PD-L1 expression's genomic context and immunotherapy response in EGFR/ALK wild-type lung adenocarcinoma.