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

A review of CDKL: An underestimated protein kinase family

Cyclin-dependent kinase-like (CDKL) family proteins are serine/threonine protein kinases and is a specific branch of CMGC (including CDK, MAPK, GSK). Its name is due to the sequence similarity with CDK and it consists of 5 members. Their function in protein phosphorylation underpins their important role in cellular activities, including cell cycle, apoptosis, autophagy and microtubule dynamics. CDKL proteins have been demonstrated to regulate the length of primary cilium, which is a dynamic and diverse signaling hub and closely associated with multiple diseases. Furthermore, CDKL proteins have been shown to be involved in the development and progression of several diseases, including cancer, neurodegenerative diseases and kidney disease. In this review, we summarize the structural characteristics and discovered functions of CDKL proteins and their role in diseases, which might be helpful for the development of innovative therapeutic strategies for disease.

Discovery and Characterization of a Chemical Probe for Cyclin-Dependent Kinase-Like 2

Acylaminoindazole-based inhibitors of CDKL2 were identified via analyses of cell-free binding and selectivity data. Compound 9 was selected as a CDKL2 chemical probe based on its potent inhibition of CDKL2 enzymatic activity, engagement of CDKL2 in cells, and excellent kinome-wide selectivity, especially when used in cells. Compound 16 was designed as a negative control to be used alongside compound 9 in experiments to interrogate CDKL2-mediated biology. A solved cocrystal structure of compound 9 bound to CDKL2 highlighted key interactions it makes within its ATP-binding site. Inhibition of downstream phosphorylation of EB2, a CDKL2 substrate, in rat primary neurons provided evidence that engagement of CDKL2 by compound 9 in cells resulted in inhibition of its activity. When used at relevant concentrations, compound 9 does not impact the viability of rat primary neurons or certain breast cancer cells nor elicit consistent changes in the expression of proteins involved in epithelial-mesenchymal transition.

Discovery and Characterization of a Chemical Probe for Cyclin-Dependent Kinase-Like 2

Acylaminoindazole-based inhibitors of CDKL2 were identified via analyses of cell-free binding and selectivity data. Compound 9 was selected as a CDKL2 chemical probe based on its potent inhibition of CDKL2 enzymatic activity, engagement of CDKL2 in cells, and excellent kinome-wide selectivity, especially when used in cells. Compound 16 was designed as a negative control to be used alongside compound 9 in experiments to interrogate CDKL2-mediated biology. A solved co-crystal structure of compound 9 bound to CDKL2 highlighted key interactions it makes within its ATP-binding site. Inhibition of downstream phosphorylation of EB2, a CDKL2 substrate, in rat primary neurons provided evidence that engagement of CDKL2 by compound 9 in cells resulted in inhibition of its activity. When used at relevant concentrations, compound 9 does not impact the viability of rat primary neurons or certain breast cancer cells nor elicit consistent changes in the expression of proteins involved in epithelial-mesenchymal transition.

Decreased CDKL2 Expression in Clear Cell Renal Cell Carcinoma Predicts Worse Overall Survival

Background: Clear cell renal cell carcinoma (ccRCC) is the most frequent and lethal type of kidney cancer. Although differential expression of cyclin-dependent kinase-like 2 (CDKL2) has been reported to be associated with tumor progression in other cancers, its prognostic value, and potential mechanism in patients with ccRCC still remain unknown.

Methods: Gene expression analysis was conducted using The Cancer Genome Atlas (TCGA), Gene Expression Omnibus, and International Cancer Genome Consortium databases. Further, clinicopathologic analysis; Kaplan–Meier survival analysis; weighted gene co-expression network analysis; gene set enrichment analysis; gene ontology enrichment; methylation; and immune infiltration analyses were performed using TCGA-kidney renal clear cell carcinoma profiles. CDKL2 translational levels were analyzed using The Human Protein Atlas database.

Results:CDKL2 expression was decreased in ccRCC samples retrieved from the four databases. Gender, survival status, histologic grade, clinical stage, TNM classification, and tumor status were closely related to CDKL2 expression. In addition, CDKL2 downregulation was an independent prognostic factor for poor prognosis in multivariate analysis. Enrichment analyses using multiple tests revealed that CDKL2 is not just closely related to immune response but this association is highly correlated as well. Further, we found that CDKL2 expression was significantly correlated with the infiltration levels of T cell CD4 memory resting; monocytes; macrophages M0, M1, and M2; dendritic cells resting; mast cells resting; plasma cells; T cell CD8; and T cell regulatory.

Conclusion: This is the first report to study the expression of CDKL2 in ccRCC, wherein we suggest that decreased CDKL2 expression is closely correlated with poor prognosis in ccRCC. We consider that CDKL2 is a novel and potential prognostic biomarker associated with immune infiltrates in ccRCC.

Integrated bioinformatics analysis of the NEDD4 family reveals a prognostic value of NEDD4L in clear-cell renal cell cancer

The members of the Nedd4-like E3 family participate in various biological processes. However, their role in clear cell renal cell carcinoma (ccRCC) is not clear. This study systematically analyzed the Nedd4-like E3 family members in ccRCC data sets from multiple publicly available databases. NEDD4L was identified as the only NEDD4 family member differentially expressed in ccRCC compared with normal samples. Bioinformatics tools were used to characterize the function of NEDD4L in ccRCC. It indicated that NEDD4L might regulate cellular energy metabolism by co-expression analysis, and subsequent gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. A prognostic model developed by the LASSO Cox regression method showed a relatively good predictive value in training and testing data sets. The result revealed that NEDD4L was associated with biosynthesis and metabolism of ccRCC. Since NEDD4L is downregulated and dysregulation of metabolism is involved in tumor progression, NEDD4L might be a potential therapeutic target in ccRCC.

Sex and Race-Related DNA Methylation Changes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer and fourth leading cause of cancer-related death worldwide. The number of HCC cases continues to rise despite advances in screening and therapeutic inventions. More importantly, HCC poses two major health disparity issues. First, HCC occurs more commonly in men than women. Second, with the global increase in non-alcoholic fatty liver diseases (NAFLD), it has also become evident that HCC is more prevalent in some races and/or ethnic groups compared to others, depending on its predisposing etiology. Most studies on HCC in the past have been focused on genetic factors as the driving force for HCC development, and the results revealed that genetic mutations associated with HCC are often heterogeneous and involve multiple pathogenic pathways. An emerging new research field is epigenetics, in which gene expression is modified without altering DNA sequences. In this article, we focus on reviewing current knowledge on HCC-related DNA methylation changes that show disparities among different sexes or different racial/ethnic groups, in an effort to establish a point of departure for resolving the broader issue of health disparities in gastrointestinal malignancies using cutting-edge epigenetic approaches.

Identification of a Set of Genes Improving Survival Prediction in Kidney Renal Clear Cell Carcinoma through Integrative Reanalysis of Transcriptomic Data

Background

With an enormous amount of research concerning kidney cancer being conducted, various treatments have been applied to its cure. However, high recurrence and metastasis rates continue to pose a threat to the survival of patients with kidney renal clear cell carcinoma (KIRC).

Methods

Data from The Cancer Genome Atlas were downloaded, and a series of analyses were performed, including differential analysis, Cox analysis, weighted gene coexpression network analysis, least absolute shrinkage and selection operator analysis, multivariate Cox analysis, survival analysis, and receiver operating characteristic curve and functional enrichment analysis.

Results

A total of 5,777 differentially expressed genes were identified from the differential analysis. The Cox analysis showed 1,853 significant genes (P < 0.01). Weighted gene coexpression network analysis revealed that 226 genes in the module were related to clinical parameters, including Tumor-Node-Metastasis (TNM) staging. Least absolute shrinkage and selection operator and multivariate Cox analyses suggested that four genes (CDKL2, LRFN1, STAT2, and SOWAHB) had a potential function in predicting the survival time of patients with KIRC. Survival analysis uncovered that a high risk of these four genes was associated with an unfavorable prognosis. Receiver operating characteristic curve analysis further confirmed the accuracy of the risk score model. The analysis of clinicopathological parameters of the four identified genes revealed that they were associated with the progression of KIRC.

Conclusion

The gene expression model consisting of CDKL2, LRFN1, STAT2, and SOWAHB is a promising tool for predicting the prognosis of patients with KIRC. The results of this study may provide insights into the diagnosis and treatment of KIRC.