Long non-coding RNA CRNDE regulates cell proliferation, migration, invasion, epithelial-mesenchymal transition and apoptosis in oral squamous cell carcinoma

The present study aimed to investigate whether the long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) can promote the migration and invasion of human oral squamous cell carcinoma (OSCC) cells via the regulation of epithelial-mesenchymal transition (EMT). CAL-27 and SCC-15 cells were classified into a control group, a small interfering negative control (si-NC) group (cells transfected with control siRNA) and an si-CRNDE group (cells transfected with CRNDE siRNA). The expression of CRNDE in OSCC tissues and cell lines was detected by in situ hybridization (ISH) and reverse transcription-quantitative polymerase chain reaction. An MTT assay was used to detect cell proliferation, flow cytometry was performed to determine cell apoptosis, wound-healing and Transwell assays were conducted to evaluate cell metastasis, and immunofluorescence staining and western blotting were performed to measure the expression of proteins associated with EMT. Tumor-bearing mouse models were established, and the tumor volumes were recorded. An immunohistochemical assay was performed to determine the expression of EMT-related proteins. CRNDE expression was increased in OSCC tissues and cell lines compared with that in normal tissues and cell lines. Compared with the control group, the si-CRNDE group displayed a reduction in the expression of CRNDE, in the proliferation, migration and invasion of cells, in the protein expression of N-cadherin, vimentin and Snail, and in the expression of proteins in the Wnt/β-catenin pathway. However, an increase was displayed in the apoptosis of cells and the expression of E-cadherin. Compared with the control group of tumor-bearing nude mice, the sh-CRNDE group demonstrated slowed tumor growth, reduced tumor weight and elevated E-cadherin, as well as reduced expression of N-cadherin, vimentin and Snail. In conclusion, silencing CRNDE may inhibit EMT, thus decreasing the migration and invasion of human OSCC cells by repressing the activation of the Wnt/β-catenin signaling pathway, thereby restricting cell growth and promoting cell apoptosis.