Decreased CDKL2 expression is correlated with the progression and poor prognosis of glioma.

Glioma is the most common form of malignant intracranial tumors. Cyclin-dependent kinase-like 2 (CDKL2) was observed in various regions of the brain, but the specific role of CDKL2 in glioma has not been reported yet. In the present study, the expression of CDKL2 mRNA was detected by real-time QPCR in freshly collected glioma and para-carcinoma tissues, and we collected genomic and clinical data from The Cancer Genome Atlas to determine mRNA expression levels of CDKL2 in the normal brain and glioma samples. Moreover, western blot assay and immunohistochemistry experiments were implemented to identify CDKL2 protein expression, and clinical pathology characteristics from 151 glioma cases and thirty-four para-carcinoma tissues were also examined. The relationship between the levels of CDKL2 expression and clinical data was analyzed. Low mRNA and protein expression of CDKL2 was observed in glioma tissues compared to non-cancerous tissues. In addition, low levels of CDKL2 correlated with Astrocytic type, higher clinical WHO grade, and higher Ki-67 expression in glioma. Low mRNA and protein expression of CDKL2 in glioma predicted an observably shorter overall survival time than high expression. However, as revealed by multivariate analysis, CDKL2 protein expression was not an independent prognostic biomarker for the survival of patients with glioma. Our study firstly determined that low levels of CDKL2 expression are associated with poor clinical diagnosis. Thus, CDKL2 may serve as a prognostic factor of glioma.