Reciprocal regulation of miR-1254 and c-Myc in oral squamous cell carcinoma suppresses EMT-mediated metastasis and tumor-initiating properties through MAPK signaling.
This study aimed to determine the effect of miR-1254 on oral squamous cell carcinoma (OSCC) metastasis and the specific mechanism involved.



The metastatic properties of OSCC cells were analyzed by transwell assays. The tumor-initiating properties of OSCC cells were analyzed by tumor sphere formation assays. The mRNA and protein expressions of targeted genes were determined by quantitative polymerase chain reaction assays and western blot analyses, respectively. Xenograft experiments were employed to evaluate the anti-metastatic effects of miR-1254 and miR-1254-mediated cancer stem cell (CSC) properties in vivo. The gene targets of miR-1254 were investigated by luciferase reporter assays. Chromatin immunoprecipitation assays were performed to observe the transcriptional regulation of miR-1254 biogenesis by transcription factor.



miR-1254 attenuated OSCC metastasis and tumor-initiating properties in vitro and in vivo. Consistent with the experimental observations, miR-1254 was decreased in late-stage OSCCs and strongly correlated with risk of OSCC metastasis. Moreover, miR-1254 was mechanistically shown to down-regulate MAP3K3, accompanied by inactivation of the MAPK signaling pathway and inhibition of epithelial-mesenchymal transition (EMT) in OSCC cells. miR-1254 was transcriptionally repressed by c-Myc to form a positive feed back loop through MAPK signaling.



Our findings suggest that miR-1254 is a potential target for the treatment of OSCCs, and miR-1254 can be clinically utilized as a biomarker for the clinical prognosis or diagnosis of OSCCs.
Department of Oral Surgery, The Union Hospital of Fujian Medical University, Fuzhou, 350001, Fujian, PR China.
Meng
M
Lu
Department of Oral Surgery, The Union Hospital of Fujian Medical University, Fuzhou, 350001, Fujian, PR China.
Wei-Hui
WH
Chen
Department of Oral Surgery, The Union Hospital of Fujian Medical University, Fuzhou, 350001, Fujian, PR China.
Cheng-Yong
CY
Wang
Department of Oral Surgery, The Union Hospital of Fujian Medical University, Fuzhou, 350001, Fujian, PR China.
Chuan-Qing
CQ
Mao
Department of Oral Surgery, The Union Hospital of Fujian Medical University, Fuzhou, 350001, Fujian, PR China.
Jin
J
Wang
D063646:Carcinogenesis / Q000378:metabolism* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology / Q000556:secondary*; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000378:metabolism*; D058750:Epithelial-Mesenchymal Transition; D025461:Feedback, Physiological; D006801:Humans; D020935:MAP Kinase Signaling System; D035683:MicroRNAs / Q000378:metabolism*; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; C558812:MIRN1254 microRNA, human; C116115:MYCBP protein, human; D035683:MicroRNAs; D014157:Transcription Factors
MAPK; Metastasis; Oral squamous cell carcinoma; miR-1254; microRNAs