CircPTK2 (hsa_circ_0003221) Contributes to Laryngeal Squamous Cell Carcinoma by the miR-1278/YAP1 Axis

Laryngeal cancer accounts for 20% of all head and neck malignancies. Laryngeal squamous cell carcinoma (LSCC) is the most common type of laryngeal cancer and is characterized by squamous differentiation, a high mortality rate, and poor prognosis. Accumulating studies have indicated that circular RNAs (circRNAs) are critical regulators in many cancers. CircPTK2 exerts an important regulatory role in several cancers. In this study, we aimed to elucidate the function of circPTK2 (hsa_circ_0003221) in LSCC. Through a series of investigations, we discovered that circPTK2 was significantly upregulated in LSCC tissues cells. Functionally, cell counting kit-8 (CCK-8) and flow cytometry analyses revealed that knockdown of circPTK2 suppressed LSCC cell viability and the cell cycle while promoting cell apoptosis. Notably, silencing circPTK2 inhibited tumor growth in vivo. Mechanistically, circPTK2 functioned as a molecular sponge of miR-1278 to upregulate YAP1 expression in LSCC cells. Moreover, YAP1 knockdown inhibited malignant phenotypes of LSCC cells. The rescue experiments showed that YAP1 overexpression reversed the effects of circPTK2 on LSCC cells. Therefore, we concluded that circPTK2 facilitates LSCC progression through the miR-1278/YAP1 axis.