CDKN3 promotes cell proliferation, invasion and migration by activating the AKT signaling pathway in esophageal squamous cell carcinoma

In China, esophageal squamous cell carcinoma (ESCC), capable of direct invasion and early metastasis, exhibits high mortality. Identification of the molecular basis driving ESCC progression and development of new diagnostic biomarkers are urgently needed. Cyclin-dependent kinase inhibitor 3 (CDKN3) performs crucial roles in the modulation of tumor development. The present study aimed to explore the functions and underlying mechanism of CDKN3 in regulating ESCC cell proliferation and invasion. The expression levels of CDKN3 in ESCC cells were evaluated by reverse transcription-quantitative PCR. Cell counting kit-8 and colony forming assays were used to evaluate cell viability. Wound-healing assay was performed to explore cell migration. Transwell invasion analysis was conducted to investigate the invasive capacity of ESCC cells. Protein levels were detected by western blot assay. The results demonstrated that the expression of CDKN3 was significantly upregulated in ESCC tissues, as predicted using the UALCAN and Gene Expression Omnibus databases. PCR and western blot assays confirmed that CDKN3 was upregulated in ESCC cell lines. Functional assays revealed that CDKN3 knockdown with small interfering RNA decreased the ability of ESCC cells to proliferate, invade and migrate and suppressed G1/S transition. Further mechanistic analyses demonstrated that CDKN3 promoted cell proliferation and invasion by activating the AKT signaling pathway in ESCC cells. To the best of our knowledge, the present study is the first to identify the functions of CDKN3 in ESCC and provide evidence that CDKN3 regulates tumor progression by activating the AKT signaling pathway. Therefore, CDKN3 may serve as a potential effective therapeutic target for ESCC treatment.