Forkhead box K2 inhibits the proliferation, migration, and invasion of human glioma cells and predicts a favorable prognosis

Abstract

Bo Wang,1–3,* XueBin Zhang,2–4,* Wei Wang,1–3 ZhiZhong Zhu,5 Fan Tang,2–4 Dong Wang,6–8 Xi Liu,9 Hao Zhuang,10 XiaoLing Yan2–4 1Department of Neurosurgery, Tianjin Huanhu Hospital, Tianjin, China; 2Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin, China; 3Tianjin Neurosurgical Institute, Tianjin, China; 4Department of Pathology, Tianjin Huanhu Hospital, Tianjin, China; 5Department of Rehabilitation, Tianjin Huanhu Hospital, Tianjin, China; 6Department of Neurosurgery, Tianjin Medical University, General Hospital, Tianjin, China; 7Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China; 8Tianjin Neurological Institute, Tianjin, China; 9Department of Gastroenterology, Tianjin NanKai Hospital, Tianjin, China; 10Department of Hepatic Biliary Pancreatic Surgery, Cancer Hospital Affiliated to Zhengzhou University, Zhengzhou, China *These authors contributed equally to this work Purpose: Forkhead box K2 (FOXK2) is a member of the forkhead box family of transcription factors. Recently, researchers discovered that overexpression of FOXK2 inhibits the proliferation and metastasis of breast cancer, non-small cell lung cancer, and colorectal cancer, and is related to the clinical prognosis. However, in hepatocellular carcinoma, FOXK2 results in the opposite phenotypes. Currently, the contribution of FOXK2 to glioma pathogenesis is not clear. Patients and methods: We evaluated the expression of FOXK2 in 151 glioma patients using immunohistochemistry assays. The associations among the expression of FOXK2, clinicopathological parameters, and the prognosis of glioma patients were statistically analyzed. We downregulated and upregulated the level of FOXK2 in glioma cells by transfections with small interfering RNA and plasmids. Then, we investigated the effects on tumor cell behavior in vitro by Cell Counting Kit-8 assays, colony-formation assay, transwell assay, and the epithelial-to-mesenchymal transition (EMT) biomarker levels.Results: The clinical data showed that expression of FOXK2 gradually decreased with increasing World Health Organization (WHO) grades and a low level of FOXK2 indicates a poor prognosis. FOXK2 expression is negatively correlated with Ki67 expression and the WHO degree but is not correlated with other clinicopathological parameters, including sex, age, Karnofsky Performance Status, tumor diameter, O-6-methylguanine-DNA methyltransferase, and glutathione S-transferase pi. FOXK2 knockdown enhances glioma cell proliferation, migration, invasion, and EMT process, and, in contrast, FOXK2 overexpression inhibits glioma cell proliferation, migration, invasion, and the EMT process.Conclusion: Expression of FOXK2 gradually decreases with increasing WHO grades. FOXK2 inhibits tumor proliferation, migration, and invasion. FOXK2 is a critical mediator of the EMT process. Keywords: Forkhead box K2, FOXK2, glioma, oncology

Keywords

• Forkhead box K 2 (FOXK2)
• Glioma
• Oncology;