No abstract

Metadherin (MTDH) is involved in tumourigenesis and cancer progression in multiple human malignancies. However, the MTDH protein has rarely been reported in laryngeal squamous cell carcinoma (LSCC). The expression pattern of the MTDH protein in 176 primary archival LSCC and 27 corresponding adjacent noncarcinoma specimens was detected by immunohistochemistry and further correlated with clinicopathological parameters. The results demonstrated that 161 (91.48%) primary LSCC samples stained positive for MTDH; however, staining was barely detectable in all adjacent noncarcinoma samples. Moreover, the expression of the MTDH protein was significantly associated with the primary tumour site (p 5 0.021), T classification (p 5 0.002), clinical stage (I 1 II/III 1 IV; p < 0.001), lymph node metastasis (p < 0.001) and postoperational recurrence (p < 0.001). Kaplan-Meier analysis revealed that MTDH expression was significantly associated with worse disease-free survival (DFS) and overall survival (OS) rates in patients with LSCC (both p < 0.001). When lymph node metastasis and MTDH expression were considered together, patients with lymph node metastasis and high MTDH expression had both poorer DFS and OS rates than others (both p < 0.001). Finally, multivariate analysis demonstrated that MTDH expression was an independent prognostic factor for both DFS and OS rates in patients with LSCC. Strong MTDH expression was negatively correlated with a canonical epithelial-mesenchymal transition molecule E-cadherin (p < 0.001) and positively associated with proangiogenic protein vascular endothelial growth factor (p < 0.001). MTDH overexpression was tightly associated with more aggressive tumour behaviour and a poor prognosis, indicating that MTDH is a valuable molecular biomarker for LSCC progression.

These results suggest that EphA2 plays a critical role in SCCHN growth and metastasis and may be a promising therapeutic target to prevent the progression of SCCHN.

Long non-coding RNAs (lncRNAs) are potentially critical regulators of cancer malignant behaviours. Aberrant expression and dysfunction of lncRNA PVT1 have been reported in multiple human cancers. However, its role in squamous cell carcinoma of the head and neck (SCCHN) remains largely unknown. Our current study demonstrated that PVT1 expression was increased in SCCHN. High PVT1 expression was positively correlated with SCCHN clinical parameters including T classification, clinical stages and cervical lymph node metastasis. More importantly, high PVT1 expression predicted a poor prognosis in SCCHN patients. Gain-of function and loss-of function studies further indicated that PVT1 promoted the proliferation and invasion of SCCHN both in vitro and in vivo, which was accompanied by epithelial-mesenchymal transition and enhanced cancer stem cell-like properties. Further mechanistic investigation revealed that PVT1 activated Wnt/β-catenin signalling pathway, and inhibition of Wnt/β-catenin signalling reversed the malignant progression caused by PVT1 overexpression. Together, our study reveals that PVT1 accelerates the malignant progression of SCCHN and represents a potential biomarker and therapeutic target in SCCHN.

These findings suggested that EphA2 may contribute to SCCHN progression and represent a novel prognostic indicator for patients with SCCHN.