LncRNA MEG3 suppresses migration and promotes apoptosis by sponging miR-548d-3p to modulate JAK-STAT pathway in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a lethal malignancy and its prognosis remains dismal. Thus, a deeper understanding of the mechanisms is needed to provide a new insight for new therapies. It has been reported that long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) was downregulated in OSCC tissues, however, its functional mechanism remains uncertain. Here, we found that the overexpression of MEG3 suppressed migration and promoted apoptosis in OSCC cell lines, while inhibition of MEG3 exhibited opposite effect. We also found that MEG3 could effectively sponge miR-548d-3p and decrease its expression level. Moreover, miR-548d-3p repressed the expression of SOCS5 and SOCS6 through binding their 3'UTR, thereby modulating the JAK-STAT signaling pathway and functioning as an oncogene in OSCC cells. Importantly, overexpression of MEG3 enhanced the expression of SOCS5 and SOCS6 to regulate JAK-STAT pathway, whereas miR-548d-3p overexpression decreased the effects of MEG3 on levels of SOCS5/SOCS6. Furthermore, upregulated expression of miR-548d-3p could abrogate the effect of MEG3 overexpression on migration and apoptosis in OSCC cell lines. In addition, the overexpression of MEG3 inhibited tumor migration and facilitated apoptosis in vivo. Together, our results revealed that MEG3 could modulate JAK-STAT pathway via miR-548d-3p/SOCS5/SOCS6 to suppresses migration and promote apoptosis in OSCC. Our research indexed a new functional mechanism of MEG3 in OSCC, and this mechanism may be a potential prognostic factor and therapeutic target. (c) 2019 IUBMB Life, 2019