CDKL3 promotes osteosarcoma progression by activating Akt/PKB

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.

CDKL3 is a promising biomarker for diagnosis and prognosis prediction in patients with hepatocellular carcinoma

Cyclin-dependent kinase-like 3 (CDKL3) has been identified as an oncogene in certain types of tumors. Nonetheless, its function in hepatocellular carcinoma (HCC) is poorly understood. In this study, we conducted a comprehensive analysis of CDKL3 based on data from the HCC cohort of The Cancer Genome Atlas (TCGA). Our analysis included gene expression, diagnosis, prognosis, functional enrichment, tumor microenvironment and metabolic characteristics, tumor burden, mRNA expression-based stemness, alternative splicing, and prediction of therapy response. Additionally, we performed a cell counting kit-8 assay, TdT-mediated dUTP nick-end Labeling staining, migration assay, wound healing assay, colony formation assay, and nude mouse experiments to confirm the functional relevance of CDKL3 in HCC. Our findings showed that CDKL3 was significantly upregulated in HCC patients compared to controls. Various bioinformatic analyses suggested that CDKL3 could serve as a potential marker for HCC diagnosis and prognosis. Furthermore, CDKL3 was found to be involved in various mechanisms linked to the development of HCC, including copy number variation, tumor burden, genomic heterogeneity, cancer stemness, and alternative splicing of CDKL3. Notably, CDKL3 was also closely correlated with tumor immune cell infiltration and the expression of immune checkpoint markers. Additionally, CDKL3 was shown to independently function as a risk predictor for overall survival in HCC patients by multivariate Cox regression analysis. Furthermore, the knockdown of CDKL3 significantly inhibited cell proliferation in vitro and in vivo, indicating its role as an oncogene in HCC. Taken together, our findings suggest that CDKL3 shows promise as a biomarker for the detection and treatment outcome prediction of HCC patients.

CDKL3 Promotes Non-small Cell Lung Cancer by Suppressing Autophagy Via Activation of PI3K/Akt/mTOR Pathway

This study aimed to assess the role of cyclin-dependent kinase-like 3 (CDKL3) in the progression of non-small cell lung cancer (NSCLC) as well as the underlying mechanisms. Western blot and qRT-PCR were utilized to analyze CDKL3 expression in 30 pairs of NSCLC and paraneoplastic tissues. A549 cells with CDKL3 knockdown and PC9 cells with CDKL3 overexpression were constructed by infecting cells with lentiviruses expressing shRNA of CDKL3 and expressing a full-length CDKL3 mRNA, respectively. The CCK-8 assay, flow cytometry, wound healing assay, and Transwell assay were carried out to detect cell viability, apoptosis, migration, and invasion, respectively. Autophagosome morphology was observed by electron microscopy experiments, the expression of key components of the PI3K/Akt/mTOR pathway was examined via Western blot and their mRNA expression levels were determined. Besides, the stably infected NSCLC cells with reduced expression or overexpression of CDKL3 were inoculated into the right-back flank of mice to generate tumors. The results showed that CDKL3 expression was dramatically increased in NSCLC tissues. Moreover, CDKL3 promoted the viability and migration of NSCLC cells by suppressing autophagy in vitro and in vivo. In addition, CDKL3 might modulate PI3K/Akt/mTOR signaling in NSCLC. Overall, CDKL3 might promote NSCLC cell viability and metastasis by inhibiting autophagy and activating the PI3K/Akt/mTOR signaling pathway.

Inhibition of CDKL3 downregulates STAT1 thus suppressing prostate cancer development

Prostate cancer poses a great threat to men's health worldwide, yet its treatment is still limited by the unclear understanding of its molecular mechanisms. CDKL3 is a molecule with a recently discovered regulatory role in human tumors, and its relationship with prostate cancer is unknown. The outcomes of this work showed that CDKL3 was significantly upregulated in prostate cancer tissues compared with adjacent normal tissues, and was significantly positively correlated with tumor malignancy. Knockdown of CDKL3 levels in prostate cancer cells significantly inhibited cell growth and migration and enhanced apoptosis and G2 arrest of the cell cycle. Cells with lower CDKL3 expression also had relatively weaker in vivo tumorigenic capacity as well as growth capacity. Exploration of downstream mechanisms of CDKL3 may regulate STAT1, which has co-expression characteristics with CDKL3, by inhibiting CBL-mediated ubiquitination of STAT1. Functionally, STAT1 is aberrantly overexpressed in prostate cancer and has a tumor-promoting effect similar to that of CDKL3. More importantly, the phenotypic changes of prostate cancer cells induced by CDKL3 were dependent on ERK pathway and STAT1. In summary, this work identifies CDKL3 as a new prostate cancer-promoting factor, which also has the potential to be a therapeutic target for prostate cancer.

Structural characteristics and immunomodulatory effects of sulfated polysaccharides derived from marine algae

Marine algae are becoming an important source of valuable candidates of functional food that remain unexplored. Compositional analysis showed that marine algae contain essential nutrients, such as carbohydrates, proteins, fats, and minerals, of which polysaccharides are the main bioactive component. Depending on the source, marine algae polysaccharides are sulfated, which have diverse structures and compositions that influence their biological activities. A growing body of evidence has demonstrated that sulfated polysaccharides derived from marine algae (SPs) exhibit various bioactivities, especially immunomodulation. This review aims at summarizing the structural characteristics of SPs, their immunomodulatory effects, and the structural-immunomodulatory activity relationships between them from articles in recent decade, in order to provide a theoretical basis for the further applications of SPs as promising food or feed additives and possible health products to modulate the immune response.

CircTP53 promotes colorectal cancer by acting as a miR-876-3p sponge to increase cyclin-dependent kinase-like 3 expression

According to ceRNA theory, circular RNAs could regulate certain protein expression through targeting corresponding microRNAs to affect the progression of multiple diseases, including colorectal cancer. CircTP53 (hsa_circ_0107702), highly expressed in thyroid cancer tissues, could promote the proliferation of thyroid cancer. However, the function of circTP53 in colorectal cancer is still unclear. In our study, we found circTP53 was significantly up-regulated in colorectal cancer tissues from patients and in colorectal cell lines. Next, using colorectal cell lines, we confirmed that circTP53 promoted the proliferation, migration and invasion, and reduced the apoptotic rate. Furthermore, through bioinformatics analysis and experimental confirmation, we found circTP53 functioned as the sponge of miR-876-3p, and miR-876-3p reversed the phenotype of circTP53 on the facilitation of colorectal cancer. Additionally, we found circTP53 promoted the progression of colorectal cancer by elevating the expression of CDKL3. At last, we suggested that circTP53 knockdown could inhibit colorectal cancer progression in vivo. In conclusion, circTP53 was highly expressed in colorectal cancer tissues, and promoted colorectal cancer progression via modulating miR-876-3p/CDKL3 axis.

CDKL3 Targets ATG5 to Promote Carcinogenesis of Esophageal Squamous Cell Carcinoma

Objective

Our previous study suggested cyclin-dependent kinase-like 3 (CDKL3) acts as a new oncogene in esophageal squamous cell carcinoma (ESCC) cell line TE-1. However, the molecular mechanisms and biological effects of CDKL3 in ESCC remain unknown. In the present study, we aimed to explore the clinical significance of CDKL3 in ESCC and how CDKL3 regulates the malignant behavior of ESCC.

Methods

ESCC samples were stained by immunohistochemical staining (IHC) and analyzed for the expression of CDKL3. The functions of CDKL3 on proliferation, apoptosis, migration, invasion, and colony formation were investigated by celigo assay, MTT assay, colony formation, caspase 3/7 activity analysis, transwell migration and invasion assay, respectively. A transplanted tumor model was established to study the functions of CDKL3 on the tumorigenesis of ESCC cells. Microarray analysis was utilized to identify the CDKL3-regulated genes in ESCC cells.

Results

ESCC tumor tissues possessed a significantly higher expression of CDKL3 and autophagy-related gene 5 (ATG5) than matched adjacent normal tissues. The high expressions of CDKL3 were positively associated with the tumor-node-metastasis (TNM) stage and Ki67. Upregulated ATG5 expression was positively correlated with male, advanced tumor (T) stage, and TNM stage. Kaplan-Meier analysis showed that ESCC patients with higher expression of CDKL3 or ATG5 had a shorter overall survival. The worst prognosis was recognized in patients with both high manifestations of CDKL3 and ATG5. Time-dependent receiver operating characteristic (ROC) curve was established to reveal that the combination of CDKL3, ATG5, and TNM stage–based model had better prognostic accuracy than TNM stage. Moreover, CDKL3 knockdown markedly repressed cell growth and aggressivity in vitro and in vivo. Mechanistically, ATG5 was confirmed as a downstream gene involved in the pro-oncogenic function of CDKL3.

Conclusion

CDKL3 can be utilized as an independent poor prognostic marker in ESCC patients. Furthermore, CDKL3 may promote tumor profession, invasion, metastasis, and prohibit tumor apoptosis partly by ATG5 activation.