miR-944 is located in an intron of the tumor protein p63 gene (TP63). miR-944 expression levels in cervical cancer tissues are significantly higher than in normal tissues and are associated with tumor size, International Federation of Gynecology and Obstetrics (FIGO) stage, lymph node metastasis, and survival. However, associations of miR-944 with its host gene, TP63, which encodes TAp63 and ΔNp63, in cervical cancer have not been fully investigated. A positive correlation between miR-944 and ΔNp63 mRNA expression was identified in cervical cancer tissues. Furthermore, when the expression of miR-944 and ΔNp63 was simultaneously inhibited, cell proliferation-, differentiation- epithelial-mesenchymal transition (EMT)-, transcription-, and virus-associated gene clusters were shown to be significantly more active according to functional annotation analysis. Cell viability and migration were more reduced upon simultaneous inhibition with anti-miR-944 or ΔNp63 siRNA than with inhibition with anti-miR-944 or ΔNp63 siRNA alone, or scramble. In addition, Western blot analysis showed that the simultaneous inhibition of miR-944 and ΔNp63 reduced EMT by increasing the expression of epithelial markers such as claudin and by decreasing mesenchymal markers such as N-cadherin and vimentin. Slug, an EMT transcription factor, was also decreased by the simultaneous inhibition of miR-944 and ΔNp63. Thus, associations between miR-944 and ΔNp63 in cervical cancer could help to elucidate the function of this intronic microRNA and its role in carcinogenesis.
Keywords: EMT; cervical cancer; miR-944; ΔNp63.