Identification of genes associated with laryngeal squamous cell carcinoma samples based on bioinformatic analysis

Postoperative radiotherapy for laryngeal cancer. The prognostic role of programmed death-ligand 1: An immune microenvironment-based cluster analysis

BACKGROUND

The prognostic role of programmed death-ligand 1 (PD-L1) expression and the tumor's immune microenvironment has yet to be investigated in the specific setting of adjuvant postoperative radiotherapy (PORT) for laryngeal carcinoma (LSCC). The main aim of this exploratory study was to investigate, also by cluster analysis, whether PD-L1 expression (in terms of combined positive score [CPS]), tumor-infiltrating lymphocytes (TIL), and tertiary lymphoid structures (TLS) correlated prognostically with response to PORT in a cohort of consecutive LSCC patients.

METHODS

PD-L1, TIL and TLS were assessed in 24 consecutive patients with LSCC who underwent PORT. Cluster analysis was used to classify cases on the strength of these parameters.

RESULTS

A CPS ≥ 1 was associated with a significantly lower recurrence rate (p = 0.033), and longer disease-free survival (DFS) (p = 0.012) than a CPS < 1. Two clusters of prognostic relevance emerged from our analysis. Cluster 1 was characterized by a mean CPS of 23.0 ± 37.9, a mean TIL count of 68.0 ± 16.4, and the presence of TLS in all cases. Cluster 2 featured a mean CPS of 3.1 ± 7.3, a mean TIL count of 23.9 ± 16.5, and no cases with TLS. Cluster 1 showed a trend towards a lower recurrence rate (p = 0.071) and longer DFS (p = 0.054) than cluster 2.

CONCLUSIONS

Judging from this preliminary investigation, assessing PD-L1 and immune microenvironment markers seems a promising approach for identifying patients at higher risk of LSCC recurrence after PORT, who might reasonably benefit from adjuvant postoperative chemo-RT, or immunotherapy.

Identification of Key Genes and Pathways in Tongue Squamous Cell Carcinoma Using Bioinformatics Analysis

BACKGROUND Tongue squamous cell carcinoma (TSCC) is a major type of oral cancers and has remained an intractable cancer over the past decades. The aim of this study was to identify differentially expressed genes (DEGs) during TSCC and reveal their potential mechanisms. MATERIAL AND METHODS The gene expression profiles of GSE13601 were downloaded from the GEO database. The GSE13601 dataset contains 57 samples, including 31 tongue SCC samples and 26 matched normal mucosa samples. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed; Cytoscape software was used for the protein-protein interaction (PPI) network and module analysis of the DEGs. RESULTS We identified a total of 1,050 upregulated DEGs (uDEGs) and 702 downregulated DEGs (dDEGs) of TSCC. The GO analysis results showed that uDEGs were significantly enriched in the following biological processes (BP): signal transduction, positive or negative regulation of cell proliferation, and negative regulation of cell proliferation. The dDEGs were significantly enriched in the following biological processes: signal transduction, cell adhesion, and apoptotic process. The KEGG pathway analysis showed that uDEGs were enriched in metabolic pathways, pathways in cancer, and PI3K-Akt signaling pathway, while the dDEGs were enriched in focal adhesion and ECM-receptor interaction. The top centrality hub genes RAC1, APP, EGFR, KNG1, AGT, and HRAS were identified from the PPI network. Module analysis revealed that TSCC was associated with significant pathways, including neuroactive ligand-receptor interaction, calcium signaling pathway, and chemokine signaling pathway. CONCLUSIONS The present study identified key genes and signal pathways, which deepen our understanding of the molecular mechanisms of carcinogenesis and development of the disease, and might be used as diagnostic and therapeutic molecular biomarkers for TSCC.