Abstract Backgrand : Laryngeal squamous cell carcinoma (LSCC), which arises from the laryngeal mucosa, is the main type of laryngeal cancer. An influence of Zinc finger protein 2 (ZIC2) expression on the occurrence and progression of LSCC has not been established. We aim to identify the clinical importance of ZIC2 expression in LSCC and to explore its latent potential mechanisms. Methods: In this study, we studied the relationship between protein and mRNA expression of ZIC2 in LSCC and clinical pathological features and prognoses via mining the high-throughput sequencing data from multiple databases and to use immunohistochemistry (IHC) and integrated analysis. Meanwhile the downstream targets of ZIC2 transcription factor were also predicted with ChlP-seq data. The KEGG, GO and PPI analysis were applied to identified the potential mechanism of ZIC2 in LSCC. After constructing ZIC2 stable expression cells, we attempt to disclose an association between ZIC2 and cell cycle and apoptosis with RT-qPCR and Western blot methods. Cell cycle was detected by flow cytometry. Results: A higher ZIC2 expression in LSCC were found in both protein and mRNA level by integrated analysis (standard mean difference, SMD=1.76 (95% CI, 1.34–2.18)). The IHC staining of ZIC2 protein is nuclear in LSCC. Kinesin family member 14 (KIF14) was explored as the potential downstream target gene of ZIC2. ZIC2 has a binding peak before the transcription start site of KIF14 and their expression were positively correlated with each other. The expression of KIF14 was elevated after overexpressing ZIC2. The KEGG analysis revealed that ZIC2 may involve LSCC by cell cycle. Cell cycle testing revealed that in ZIC2 knockdown cells, G1 phase increased while S phase was decreased. After knockdown ZIC2 expression, the expression of P21 was elevated, Bax protein was increased while Bcl2 decreased. The analysis of the summary receiver operating characteristic (sROC) demonstrated that ZIC2 may have potential to become a diagnostic marker for LSCC. Conclusions: In conclusion, up-regulation of ZIC2 may contribute to LSCC pathogenesis in cell cycle pathway and it may target KIF14 in LSCC, but these need further research in the future.

Background: Currently, high expression of WD repeat and HMG-box DNA binding protein 1 (WDHD1) has been found in a variety of tumors; but there is no research has been conducted concerning the expression of WDHD1 in laryngeal squamous cell carcinoma (LSCC). Our purpose is to investigate the expression and the latent mechanism of WDHD1 in LSCC. Methods: Firstly, 9 data sets from the Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and ArrayExpress were statistically analyzed to explore the expression of WDHD1 in LSCC; immunohistochemistry was performed in 79 LSCC tissues and 44 non-cancer tissues to further verify the result. In addition, the target gene of WDHD1 was predicted and immunohistochemistry was used to detect the expression of the target gene. The potential mechanism of WDHD1 in LSCC was investigated by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and protein-protein interaction network (PPI). Results: The WDHD1 mRNA was expressed at higher levels in the LSCC tissue than in the normal tissue (SMD=1.90, 95% CI=1.50-2.30); and the results of immunohistochemistry were consistent with the conclusion. Using chip-seq analysis, we found that S-phase kinase-associated protein 2 (Skp2) had a significant binding peak with WDHD1, and the expression of these two genes was significantly positively correlated. Immunohistochemistry showed that Skp2 was also highly expressed in LSCC. In addition, GO and KEGG analysis revealed the WDHD1 positively correlated genes was closely related to cell cycle, and PPI analysis identified 10 hub genes: COL7A1, COL4A2, COL4A1, COL4A6, COL11A1, COL5A2, COL1A1, COL13A1, COL8A1 and COL10A1, which may be critical to the progression of LSCC. Conclusions: WDHD1 was overexpressed in LSCC tissues. Meanwhile, WDHD1 and its target gene Skp2 for transcriptional regulation may play a role in the progression of LSCC by regulating the cell cycle.