Affiliations: Department of Otorhinolaryngology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
Correspondence:
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Corresponding author: Guohua Hu, Department of Otorhinolaryngology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China. Tel.: +86 23 89012945; Fax: +86 23 89012981; E-mail: hghxxcq@sina.com.
Abstract: BACKGROUND: Downregulation of PCDH20 is frequently involved in tumorigenesis of many cancers, but the role of PCDH20 protein in hypopharyngeal squamous cell carcinoma (HSCC) is still unknown. OBJECTIVE: The aim of this study was to investigate the role of PCDH20 in hypopharyngeal squamous cell carcinoma (HSCC). METHODS: Immunohistochemistry (IHC) and qRT-PCR was carried out to estimate the expressions of PCDH20 protein and mRNA in HSCC tissues and adjacent non-tumor tissues. Correlation between the PCDH20 expression and clinicopathological characteristics was evaluated using chi-square test. Meanwhile, Kaplan-Meier method and log-rank test were applied to analyze the overall survival. After transfection of PCDH20, the CCK8 assay, Cell migration assay and invasion assay were used to investigate the changes in the viability, migration and invasion of Fuda cells. The mechanisms by which reduced PCDH20 promote migration and invasion of Fuda cells were examined using western blotting. RESULTS: PCDH20 protein showed in tumor tissue low expression rates of 67.5% (54/80). The mRNA of PCDH20 indicated the consistent trend (80%, 8/10). Reduced PCDH20 expression was positively related to T stage and lymph node metastasis (P< 0.05). Patients with low levels of PCDH20 had worse overall survival compared with those with high PCDH20 levels (P< 0.001). The univariate Cox regression analysis described that lymph node metastasis (P= 0.043) and down-regulated PCDH20 expression (P= 0.045) were significantly prognostic factors.Multivariate analysis suggested that low PCDH20 expression (P= 0.015) were significantly independent prognostic factors for overall survival. PCDH20 in Fadu cells significantly inhibited cell viability, migration and invasion. Meanwhile, PCDH20 was involved in the disruption of HSCC progression through antagonizing its downstream Wnt/β-catenin signalling pathway. CONCLUSION: Our data highlight that the downregulated PCDH20 may serve as reliable diagnostic biomarker in HSCC.
