miR-182-5p Promotes Growth in Oral Squamous Cell Carcinoma by Inhibiting CAMK2N1

Emerging evidence suggests that the propagation of oral squamous cell carcinoma (OSCC) is influenced by the abnormal expression of microRNAs (miRNAs). This study aimed to characterize the involvement of miR-182-5p in OSCC by targeting the calcium/ calmodulin-dependent protein kinase II inhibitor CAMK2N1.

miR-182-5p expression was quantified in OSCC tissues and cell lines with reverse transcription polymerase chain reaction (RT-PCR). Cell colony formation, Cell Counting Kit-8 (CCK-8), Ki-67, and nude mouse xenograft assays were used to characterize the role of miR-182-5p in the proliferation of OSCC. A miR-182-5p target gene was identified with western blotting, RT-PCR, and luciferase activity assays. OSCC patient survival based on CAMK2N1 expression was also analyzed.

miR-182-5p was up-regulated in in vitro cell lines and in vivo clinical OSCC samples. CCK-8, colony formation, and Ki-67 assays revealed that miR-182-5p promoted the growth and proliferation of OSCC cells. miR-182-5p directly targeted CAMK2N1, as evidenced by luciferase assays and target prediction algorithms. CAMK2N1 operated as a tumor suppressor gene in patients with OSCC. Down-regulating miR-182-5p expression in the CAL-27 cell line restored CAMK2N1-mediated OSCC cell proliferation. miR-182-5p expression inhibited the activation of AKT, ERK1/2, and NF-κB. Mice injected with CAL-27 cells transfected with miR-182-5p-inhibitor demonstrated a significant increase in tumor size and weight and increased CAMK2N1 mRNA and protein expression compared with the miR-negative control group.

The miR-182-5p-CAMK2N1 pathway can be potentially targeted to regulate the proliferation of OSCC cells.