Differences of miRNA expression associated with ΔNp63β overexpressing OSCC cell line SQUU-B

Recent reports have revealed that EMT is involved in cancer invasion and progression including oral squamous cell carcinoma (OSCC). Previously, we have also studied on the association of p63 gene, a homolog of the p53 tumor suppressor gene, with EMT in OSCC cells. Furthermore, we also demonstrated that down-regulation of ΔNp63 accompanied with EMT and that re-expression of ΔNp63β by stable cDNA transfection in OSCC cell lines reverted the EMT phenotype. However, the detail mechanisms of ΔNp63β-mediated EMT remain to be unclear. Recent studies have shown that several microRNAs (miRNAs) are also involved in EMT process of human cancer by targeting EMT-related transcription factors. We thus sought to identify responsible miRNA associated with ΔNp63β-mediated EMT using miRNA microarray analyses. As samples for miRNA microarray, we used two clones established from an OSCC cell line SQUU-B, which lacks ΔNp63 expression and displays EMT phenotypes. One is SQUU-BO cell overexpressing ΔNp63β, and another is SQUU-BC cell transfected with empty vector. In addition, SQUU-B EL cells with low expression of E-cadherin were also used to identify the miRNA associated with E-cadherin expression strongly.