Downregulation of zinc finger protein 71 expression in oral squamous cell carcinoma tissues and its underlying molecular mechanism.

BACKGROUND: Patients with oral squamous cell carcinoma (OSCC) have poor prognoses due to a limited understanding of the pathogenesis of OSCC. Zinc finger protein (ZNF) is the largest transcription factor family in the human genome and exert diverse and important functions. Nevertheless, the exact expression status and molecular mechanism of ZNF71 have not been described in OSCC. Therefore, this study aimed to identify the specific expression level of ZNF71 in OSCC tissues and to further interpret the potential molecular mechanism of ZNF71 in the pathogenesis of OSCC. METHODS: In-house immunohistochemical staining of 116 OSCC samples and 29 non-OSCC samples was employed to detect the expression status of ZNF71 at the protein level of OSCC tissues. Single-cell RNA sequencing data from 7 OSCC samples was used to explore the expression landscape of ZNF71 in different cell types from OSCC tissues. High-throughput RNA sequencing data and gene chips data from 893 OSCC samples and 301 non-OSCC samples were utilized to identify the specific expression level of ZNF71 at the bulk mRNA level of OSCC tissues. Here, standardized mean difference (SMD) value was applied to calculate the expression differences between OSCC group and non-OSCC group. Multiple datasets were included; hence, the results were considered to be more reliable. Sensitivity analysis was conducted to evaluate the stability of the results. Enrichment analysis and immune infiltration analysis were used to explore the underlying molecular mechanism of ZNF71 in OSCC. RESULTS: ZNF71 was significantly downregulated in OSCC tissues at the protein level (SMD = -1.96, 95 % confidence interval [95 % CI]: -2.43 to -1.50). ZNF71 was absent in various cell types from OSCC tissues including cancerous epithelial cells and tumor-infiltrating immune cells. ZNF71 was downregulated in OSCC tissues at the bulk mRNA level (SMD = -0.38, 95 % CI: -0.75 to -0.02). Enrichment analysis showed that positively and differentially co-expressed genes mainly concentrated on "herpes simplex virus 1 infection" and "regulation of plasma membrane bounded cell projection organization", and negatively and differentially co-expressed genes mainly participated in "cell cycle" and "DNA metabolic process". Moreover, the putative target genes of ZNF71 mainly participated in "cellular respiration" and "protein catabolic process". Finally, immune infiltration analysis revealed that ZNF71 expression was positively correlated with multiple immune cells including activated B cells, memory B cells, and natural killer (NK) cells, and negatively correlated with various immune cells, including CD56 bright NK cells, neutrophil, and immature dendritic cells. CONCLUSION: The downregulation of ZNF71 may influence the initiation and promotion of OSCC by reducing immune infiltration, accelerating cell cycle progression, and affecting metabolic process, and this requires further research.

Drug repositioning in head and neck squamous cell carcinoma: An integrated pathway analysis based on connectivity map and differential gene expression.

The severe damage to health and social burden caused by head and neck squamous cell carcinoma (HNSCC) generated an urgent need to develop novel anti-cancer therapy. Currently, drug repositioning has risen in responses to the proper time as an efficient approach to invention of new anti-cancer therapies. In the present study, we aimed to screen candidate drugs for HNSCC by integrating HNSCC-related pathways from differentially expressed genes (DEGs) and drug-affected pathways from connectivity map (CMAP). We also endeavored to unveil the molecular mechanism of HNSCC through creating drug-target network and protein-to-protein (PPI) network of component DEGs in key overlapping pathways. As a result, a total of 401 DEGs were obtained from TCGA and GTEx mRNA-seq data. Taking the intersection part of 27 HNSCC-related Kyoto Encyclopedia of Genes and Genomes pathways and 33 drug-affected pathways, we retained 22 candidate drugs corresponding to two key pathways (cell cycle and p53 signaling pathways) of the five overlapping pathways. Two of the hub genes (PCNA and CCND1) identified from the PPI network of component DEGs in cell cycle and p53 signaling pathways were defined as the critical targets of candidate drugs with increased protein expression in HNSCC tissues, which was reported by the human protein atlas (HPA) database and cBioPortal. Finally, we validated via molecular docking analysis that two drugs with unknown effects in HNSCC: MG-262 and bepridil might perturb the development of HNSCC through targeting PCNA. These candidate drugs possessed broad application prospect as medication for HNSCC.

Expression level and prospective mechanism of miRNA-99a-3p in head and neck squamous cell carcinoma based on miRNA-chip and miRNA-sequencing data in 1, 167 cases.

BACKGROUND: The role of miR-99a-3p in Head and neck squamous cell carcinoma (HNSCC) has not been reported. Therefore, in this study, we examined the expression level and its molecular mechanisms of miR-99a-3p in HNSCC. MATERIALS AND METHODS: MiR-99a-3p-related miRNA-chip and miRNA-sequencing data were collected. We then carried out meta-analyses to pool the standard mean difference (SMD) value and generate a summarized receiver operating characteristic (sROC) curve. MiR-99a-3p mimic was transfected into FaDu cells and those genes influenced by miR-99a-3p were gathered. The target genes were also predicted from 12 tools through miRwalk2.0, and combined with differentially expressed genes in HNSCC from the The Cancer Genome Atlas and Genotype-Tissue Expression sequencing databases. FunRich and DAVID were used for the pathway signaling analyses for the potential targets of miR-99a-3p in HNSCC. RESULTS: The SMD was -0.30 (95% CI: -0.51, -0.08) in the fixed-effect model and -0.28 (95% CI: -0.67, 0.10) in the random-effect model (I2 = 60%), indicating a reduced expression level of miR-99a-3p in HNSCC tissues based on 1167 cases. In the sROC curve, the area under the curve (AUC) was 0.77 (95% CI: 0.73, 0.81). The 251 potential targets of miR-99a-3p were enriched in several pathways related to cancer, with the "Pathways in cancer" standing at the top. vascular endothelial growth factor A was selected as an example with up-regulated trend in HNSCC tissues. CONCLUSION: MiR-99a-3p exhibits a significant lower expression status in HNSCC, and this reduced or deletion status promotes the malignant progression of HNSCC. However, its molecular mechanism is still unclear and requires further investigation.

A regulatory mutant on TRIM26 conferring the risk of nasopharyngeal carcinoma by inducing low immune response.

The major histocompatibility complex (MHC) is most closely associated with nasopharyngeal carcinoma (NPC), but the complexity of its genome structure has proven challenging for the discovery of causal MHC loci or genes. We conducted a targeted MHC sequencing in 40 Cantonese NPC patients followed by a two-stage replication in 1065 NPC cases and 2137 controls of Southern Chinese descendent. Quantitative RT-PCR analysis (qRT-PCR) was used to detect gene expression status in 108 NPC and 43 noncancerous nasopharyngeal (NP) samples. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) were used to assess the transcription factor binding site. We discovered that a novel SNP rs117565607_A at TRIM26 displayed the strongest association (OR = 1.909, Pcombined = 2.750 × 10-19 ). We also observed that TRIM26 was significantly downregulated in NPC tissue samples with genotype AA/AT than TT. Immunohistochemistry (IHC) test also found the TRIM26 protein expression in NPC tissue samples with the genotype AA/AT was lower than TT. According to computational prediction, rs117565607 locus was a binding site for the transcription factor Yin Yang 1 (YY1). We observed that the luciferase activity of YY1 which is binding to the A allele of rs117565607 was suppressed. ChIP data showed that YY1 was binding with T not A allele. Significance analysis of microarray suggested that TRIM26 downregulation was related to low immune response in NPC. We have identified a novel gene TRIM26 and a novel SNP rs117565607_A associated with NPC risk by regulating transcriptional process and established a new functional link between TRIM26 downregulation and low immune response in NPC.