Elevated expression of miR‐301a and its functional roles in canine oral melanoma

Abstract

AbstractmiR‐301a is one of numerous dysregulated microRNAs (miRNAs) in canine oral melanoma (COM), one of which is miR‐301a (upregulated). Its biological role has been described in various human cancer types, including malignant melanoma, but not in COM. Accordingly, in this study, we investigated miR‐301a expression in COM in greater detail to ascertain whether it could serve as a diagnostic biomarker, elucidate its functional roles in this cancer, and predict the possible pathways by which it exerts its effects. Relative expression of miR‐301a was investigated in clinical oral tissue and plasma samples and COM cell (KMeC and LMeC) lines using qRT‐PCR. Knockdown of miR‐301a was also validated for KMeC and LMeC cells using qRT‐PCR. We performed CCK‐8 assays to assess cell proliferation, monolayer wound‐healing, and transwell migration assays to assess cell migration, a colony‐formation assay to assess clonogenicity, a TUNEL assay and flow cytometry to assess apoptosis‐related effects, and gene enrichment analyses to predict possible related pathways. miR‐301a was markedly upregulated in COM oral tissue and plasma clinically, suggesting its potential as a diagnostic biomarker for COM diagnosis. In vitro assays demonstrated that miR‐301 significantly inhibited apoptosis in COM cells while promoting cell migration, proliferation, and clonogenicity. We also predicted that miR‐301 exerts cancer‐promoting effects through the Wnt signalling pathway for COM. Our findings suggest that miR‐301a is a COM oncomiR that regulates several oncogenic phenotypes with the potential to be a diagnostic biomarker.