High expression of NEK2 promotes lung cancer progression and drug resistance and is regulated by mutant EGFR

Role of NEK2 in tumorigenesis and tumor progression

Never in mitosis A (NIMA)-related kinase 2 (NEK2) is a serine/threonine kinase found in the nucleus and cytoplasm throughout the cell cycle. NEK2 is overexpressed in many cancers and is a biomarker of poor prognosis. Factors contributing to NEK2 elevation in cancer cells include oncogenic transcription factors, decreased ubiquitination, DNA methylation, and the circular RNA (circRNA)/long noncoding RNA (lncRNA)-miRNA axis. NEK2 overexpression produces chromosomal instability and aneuploidy, thereby enhancing cancer progression and suppressing antitumor immunity, which highlights the prominence of NEK2 in tumorigenesis and tumor progression. Small-molecule inhibitors targeting NEK2 have demonstrated promising therapeutic potential in vitro and in vivo across various cancer types. This review outlines the regulatory mechanisms of NEK2 expression, emphasizes its functional roles in cancer initiation and progression, and highlights the anticancer properties of NEK2 inhibitors.

NEK2 promotes esophageal squamous cell carcinoma cell proliferation, migration and invasion through the Wnt/β-catenin signaling pathway

OBJECTIVES

The NEK2 (never in mitosis gene A-related kinase 2), a serine/threonine kinase involved in chromosome instability and tumorigenesis. Hence, this study aimed to explore the molecular function of NEK2 in esophageal squamous cell carcinoma (ESCC).

METHODS

By available transcriptome datasets (GSE53625 cohort, GSE38129 cohort, and GSE21293 cohort), we analyzed the differentially expressed genes in invading and non-invading ESCC. Subsequently, we evaluated the association between NEK2 expression level and clinical outcomes through Kaplan-Meier analysis method. The quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) analyses were performed to determine the expression levels of NEK2 mRNA and protein, respectively. We knocked down the NEK2 expression in ESCC cells (ECA109 and TE1), and evaluated the NEK2 biology function associated with ESCC cell proliferation, migration, invasion, and colony formation abilities. Finally, the downstream pathway of NEK2 was analyzed through Gene Set Enrichment Analysis (GSEA) and validated the regulatory mechanism of NEK2 on the potential pathway through WB.

RESULTS

We found that NEK2 was highly expressed in ESCC cells compared with human esophageal epithelial cells (HEEC) (P < 0.0001), and high NEK2 expression was remarkably associated with poor survival (P = 0.019). Knockdown of NEK2 showed the significant inhibitory effect for tumorigenesis, and suppressed the ESCC cells proliferation, migration, invasion, and formation of colonies abilities. Additionally, GSEA revealed that Wnt/β-catenin pathway was a downstream pathway of NEK2. WB results further validated the regulatory mechanism of NEK2 for Wnt/β-catenin signaling.

CONCLUSIONS

Our results indicated that NEK2 promotes ESCC cell proliferation, migration and invasion by activating the Wnt/β-catenin pathway. NEK2 could be a promising target for ESCC.

In silico analysis revealed the potential circRNA-miRNA-mRNA regulative network of non-small cell lung cancer (NSCLC)

BACKGROUND

The primary source of death in the world is non-small cell lung cancer (NSCLC). However, NSCLCs pathophysiology is still not completely understood. The current work sought to study the differential expression of mRNAs involved in NSCLC and their interactions with miRNAs and circRNAs.

METHODS

We utilized three microarray datasets (GSE21933, GSE27262, and GSE33532) from the GEO NCBI database to identify the differentially expressed genes (DEGs) in NSCLC. We employed DAVID Functional annotation tool to investigate the underlying GO biological process, molecular functions, and KEGG pathways involved in NSCLC. We performed the Protein-protein interaction (PPI) network, MCODE, and CytoHubba analysis from Cytoscape software to identify the significant DEGs in NSCLC. We utilized miRnet to anticipate and build interaction between miRNAs and mRNAs in NSCLC and ENCORI to predict the miRNA-circRNA relationships and build the ceRNA regulatory network. Finally, we executed the gene expression and Kaplan-Meier survival analysis to validate the significant DEGs in the ceRNA network utilizing TCGA NSCLC and GEPIA data.

RESULTS

We revealed a total of 156 overlapped DEGs (47 upregulated and 109 downregulated genes) in NSCLC. The PPI network, MCODE, and CytoHubba analysis revealed 12 hub genes (cdkn3, rrm2, ccnb1, aurka, nuf2, tyms, kif11, hmmr, ccnb2, nek2, anln, and birc5) that are associated with NSCLC. We identified that these 12 genes encode 12 mRNAs that are strongly linked with 8 miRNAs, and further, we revealed that 1 circRNA was associated with this 5 miRNA. We constructed the ceRNAs network that contained 1circRNA-5miRNAs-7mRNAs. The expression of these seven significant genes in LUAD & LUSC (NSCLC) was considerably higher in the TCGA database than in normal tissues. Kaplan-Meier survival plot reveals that increased expression of these hub genes was related to a poor survival rate in LUAD.

CONCLUSION

Overall, we developed a circRNA-miRNA-mRNA regulation network to study the probable mechanism of NSCLC.

Evaluating the Expression and Prognostic Value of Genes Encoding Microtubule-Associated Proteins in Lung Cancer

Microtubule-associated proteins (MAPs) play essential roles in cancer development. This study aimed to identify transcriptomic biomarkers among MAP genes for the diagnosis and prognosis of lung cancer by analyzing differential gene expressions and correlations with tumor progression. Gene expression data of patients with lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) from the Cancer Genome Atlas (TCGA) database were used to identify differentially expressed MAP genes (DEMGs). Their prognostic value was evaluated by Kaplan-Meier and Cox regression analysis. Moreover, the relationships between alterations in lung cancer hallmark genes and the expression levels of DEMGs were investigated. The candidate biomarker genes were validated using three independent datasets from the Gene Expression Omnibus (GEO) database and by quantitative reverse transcription polymerase chain reaction (qRT-PCR) on clinical samples. A total of 88 DEMGs were identified from TCGA data. The 20 that showed the highest differential expression were subjected to association analysis with hallmark genes. Genetic alterations in TP53, EGFR, PTEN, NTRK1, and PIK3CA correlated with the expression of most of these DEMGs. Of these, six candidates-NUF2, KIF4A, KIF18B, DLGAP5, NEK2, and LRRK2-were significantly differentially expressed and correlated with the overall survival (OS) of the patients. The mRNA expression profiles of these candidates were consistently verified using three GEO datasets and qRT-PCR on patient lung tissues. The expression levels of NUF2, KIF4A, KIF18B, DLGAP5, NEK2, and LRRK2 can serve as diagnostic biomarkers for LUAD and LUSC. Moreover, the first five can serve as prognostic biomarkers for LUAD, while LRRK2 can be a prognostic biomarker for LUSC. Our research describes the novel role and potential application of MAP-encoding genes in clinical practice.

NEK2 promotes the migration and proliferation of ESCC via stabilization of YAP1 by phosphorylation at Thr-143

BACKGROUND

Esophageal Squamous Cell Carcinoma (ESCC) was characterized as a regional-prevalent and aggressive tumor with high morbidity and mortality. NIMA-related kinase 2 (NEK2) is an interesting oncogene, the alteration of which leads to patients-beneficial outcomes. We aimed to explore the role of NEK2 in ESCC and excavate its mechanism.

METHODS

RNA-seq data were downloaded from TCGA and GEO and analyzed by R software. The protein levels were detected by immunohistochemistry (IHC) or western blot (WB), and mRNA expression was detected by qRT-PCR. The in vitro role of proliferation and migration was detected by Transwell migration assay and by colony formation assay, respectively. The in vivo roles were explored using a subcutaneous xenograft tumor model, where immunofluorescence (IF) and IHC were employed to investigate expression and localization. The interaction between proteins was detected by immunoprecipitation. The stability of proteins was measured by WB in the presence of cycloheximide.

RESULTS

A higher level of NEK2 was found in ESCC than normal esophageal epithelia in GEO, TCGA, and tissue microarray, which was associated with worse prognoses. The NEK2 knockdown impaired the proliferation and migration of ESCC, which also downregulated YAP1 and EMT markers like N-cadherin and Vimentin in vitro. On the contrary, NEK2 overexpression enhanced the migration of ESCC and elevated the levels of YAP1, N-cadherin, and Vimentin. Additionally, the overexpression of YAP1 in NEK2 knocked down ESCCs partly rescued the corresponding decrease in migration. The knockdown of NEK2 played an anti-tumor role in vivo and was accompanied by a lower level and nucleus shuffling of YAP1. In mechanism, NEK2 interacted with YAP1 and increased the stability of both endogenous and exogenous YAP1 by preventing ubiquitination. Moreover, the computer-predicted phosphorylation site of YAP1, Thr-143, reduced the ubiquitination of HA-YAP1, strengthened its stability, and thus influenced the migration in vitro.

CONCLUSIONS

NEK2 is a prognostic oncogene highly expressed in ESCC and promotes the progression of ESCC in vitro and in vivo. Mechanistically, NEK2-mediated phosphorylation of YAP1 at Thr-143 protects it from proteasome degradation and might serve as a promising therapeutic target in ESCC. Video Abstract.

A New Risk Model Based on 7 Quercetin-Related Target Genes for Predicting the Prognosis of Patients With Lung Adenocarcinoma

Background: Studies have reported that quercetin inhibits the growth and migration of lung adenocarcinoma (LUAD). This study aimed to explore the roles and mechanisms of quercetin target genes in the progression of LUAD.

Methods: The quercetin structure and potential target genes of quercetin were explored in the Traditional Chinese Medicine Systems Pharmacology and SwissTargetPrediction databases. The differentially expressed quercetin target genes were identified in The Cancer Genome Atlas (TCGA) database, and the clinical values of quercetin target genes were explored. Subsequently, a risk model was constructed via the Cox regression and survival analysis to evaluate the potential effects and possible mechanisms of quercetin target genes.

Results: The quercetin differential target genes involved in biological processes such as the oxidation-reduction process, cell proliferation, G2/M transition of the mitotic cell cycle, and were related to the lung cancer. NEK2, TOP2A, PLK1, CA4, CDK5R1, AURKB, and F2 were related to the prognosis, and were independent factors influencing the prognosis of LUAD patients. The risk model was related to the gender, clinical stage, T stage, lymph node metastasis, and survival status of LUAD patients, and was independent risk factor associated with poor prognosis. In the high-risk group, the risk model involved signaling pathways such as cell cycle, DNA replication, spliceosome, and homologous recombination.

Conclusion: The quercetin potential target genes NEK2, TOP2A, PLK1, CA4, CDK5R1, AURKB, and F2 were related to the diagnosis and prognosis of LUAD patients. A risk model based on 7 quercetin target genes could be used to assess the prognosis of patients with LUAD.

In Mitosis You Are Not: The NIMA Family of Kinases in Aspergillus, Yeast, and Mammals

The Never in mitosis gene A (NIMA) family of serine/threonine kinases is a diverse group of protein kinases implicated in a wide variety of cellular processes, including cilia regulation, microtubule dynamics, mitotic processes, cell growth, and DNA damage response. The founding member of this family was initially identified in Aspergillus and was found to play important roles in mitosis and cell division. The yeast family has one member each, Fin1p in fission yeast and Kin3p in budding yeast, also with functions in mitotic processes, but, overall, these are poorly studied kinases. The mammalian family, the main focus of this review, consists of 11 members named Nek1 to Nek11. With the exception of a few members, the functions of the mammalian Neks are poorly understood but appear to be quite diverse. Like the prototypical NIMA, many members appear to play important roles in mitosis and meiosis, but their functions in the cell go well beyond these well-established activities. In this review, we explore the roles of fungal and mammalian NIMA kinases and highlight the most recent findings in the field.

NcRNA-Mediated High Expression of HMMR as a Prognostic Biomarker Correlated With Cell Proliferation and Cell Migration in Lung Adenocarcinoma

Background

Hyaluronan-mediated motility receptor (HMMR) plays a pivotal role in cell proliferation in various cancers, including lung cancer. However, its function and biological mechanism in lung adenocarcinoma (LUAD) remain unclear.

Methods

Data on HMMR expression from several public databases were extensively analyzed, including the prognosis of HMMR in the Gene Expression Profiling Interactive Analysis (GEPIA) database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed using DAVID and gene set enrichment analysis (GSEA) software. The correlation between HMMR expression and immune cell infiltration was analyzed in the Tumor Immune Estimation Resource (TIMER) database, and the gene and protein networks were examined using the GeneMANIA and STRING databases. Experimentally, the expression of HMMR in LUAD and lung cancer cell lines was determined using immunohistochemistry and quantitative RT-PCR assays. Besides, the function of HMMR on cancer cell proliferation and migration was examined using cell growth curve and colony formation, Transwell, and wound healing assays.

Results

In this study, we found that HMMR was elevated in LUAD and that its high expression was associated with poor clinicopathological features and adverse outcomes in LUAD patients. Furthermore, our results demonstrated that the expression of HMMR was positively correlated with immune cell infiltration and immune modulation. Interestingly, diverse immune cell infiltration affects the prognosis of LUAD. In the functional assay, depletion of HMMR significantly repressed the cancer cell growth and migration of LUAD. Mechanically, we found that that the DNA methylation/TMPO-AS1/let-7b-5p axis mediated the high expression of HMMR in LUAD. Depletion of TMPO-AS1 and overexpression of let-7b-5p could result in the decreased expression of HMMR in LUAD cells. Furthermore, we found that TMPO-AS1 was positively correlated with HMMR, yet negatively correlated with let-7b-5p expression in LUAD.

Conclusions

Our findings elucidated that the DNA methylation/TMPO-AS1/let-7b-5p axis mediated the high expression of HMMR, which may be considered as a biomarker to predict prognosis in LUAD.

One shoot, three birds: Targeting NEK2 orchestrates chemoradiotherapy, targeted therapy, and immunotherapy in cancer treatment

Combinational therapy has improved the cancer therapeutic landscape but is associated with a concomitant increase in adverse side reactions. Emerging evidence proposes that targeting one core target with multiple critical roles in tumors can achieve combined anti-tumor effects. This review focuses on NEK2, a member of serine/threonine kinases, with broad sequence identity to the mitotic regulator NIMA of the filamentous fungus Aspergillus nidulans. Elevated expression of NEK2 was initially found to promote tumorigeneses through abnormal regulation of the cell cycle. Subsequent studies report that NEK2 is overexpressed in a broad spectrum of tumor types and is associated with tumor progression and therapeutic resistance. Intriguingly, NEK2 has recently been revealed to mediate tumor immune escape by stabilizing the expression of PD-L1. Targeting NEK2 is thus becoming a promising approach for cancer treatment by orchestrating chemoradiotherapy, targeted therapy, and immunotherapy. It represents a novel strategy for inducing combined anti-cancer effects using a mono-agent.

Analysis of the effect of NEKs on the prognosis of patients with non-small-cell lung carcinoma based on bioinformatics

NEKs are proteins that are involved in various cell processes and play important roles in the formation and development of cancer. However, few studies have examined the role of NEKs in the development of non-small-cell lung carcinoma (NSCLC). To address this problem, the Oncomine, UALCAN, and the Human Protein Atlas databases were used to analyze differential NEK expression and its clinicopathological parameters, while the Kaplan-Meier, cBioPortal, GEPIA, and DAVID databases were used to analyze survival, gene mutations, similar genes, and biological enrichments. The rate of NEK family gene mutation was high (> 50%) in patients with NSCLC, in which NEK2/4/6/8/ was overexpressed and significantly correlated with tumor stage and nodal metastasis status. In addition, the high expression of NEK2/3mRNA was significantly associated with poor prognosis in patients with NSCLC, while high expression of NEK1/4/6/7/8/9/10/11mRNA was associated with good prognosis. In summary, these results suggest that NEK2/4/6/8 may be a potential prognostic biomarker for the survival of patients with NSCLC.

ETV4 mediated lncRNA C2CD4D-AS1 overexpression contributes to the malignant phenotype of lung adenocarcinoma cells via miR-3681-3p/NEK2 axis

Lung adenocarcinoma (LUAD) is originated from the mucus-producing glands of the lungs. The involvement of long noncoding RNAs (lncRNAs) has been discovered in multiple diseases. In the present research, we aimed to unmask the role of C2CD4D and THEM5 antisense RNA 1 (C2CD4D-AS1) in LUAD. RT-qPCR or western blot analysis was respectively applied in the detection of RNA or protein expressions. The function of C2CD4D-AS1 in LUAD was assessed by functional assays. Through ChIP, RNA pull down, DNA pull down, RIP and luciferase reporter assays, the in-depth regulatory mechanism of C2CD4D-AS1 in LUAD was explored. C2CD4D-AS1 was dramatically overexpressed in LUAD tissues and cell lines. As a result, depletion of C2CD4D-AS1 significantly repressed cell proliferation, migration, invasion and stimulated cell apoptosis in LUAD. Mechanistically, ETS variant transcription factor 4 (ETV4) activated the transcription of C2CD4D-AS1 and stimulated its up-regulation in LUAD cells, thus affecting LUAD cell biological functions. Furthermore, C2CD4D-AS1 sponged microRNA-3681-3p (miR-3681-3p) and regulated NIMA-related kinase 2 (NEK2), thus participating in modulating LUAD cell biological behaviors. To conclude, C2CD4D-AS1 up-regulation induced by ETV4 enhanced NEK2 expression by sequestering miR-3681-3p to contribute to the malignant behaviors of LUAD cells.

The Hypoxia-Long Noncoding RNA Interaction in Solid Cancers

Hypoxia is one of the representative microenvironment features in cancer and is considered to be associated with the dismal prognosis of patients. Hypoxia-driven cellular pathways are largely regulated by hypoxia-inducible factors (HIFs) and notably exert influence on the hallmarks of cancer, such as stemness, angiogenesis, invasion, metastasis, and the resistance towards apoptotic cell death and therapeutic resistance; therefore, hypoxia has been considered as a potential hurdle for cancer therapy. Growing evidence has demonstrated that long noncoding RNAs (lncRNAs) are dysregulated in cancer and take part in gene regulatory networks owing to their various modes of action through interacting with proteins and microRNAs. In this review, we focus attention on the relationship between hypoxia/HIFs and lncRNAs, in company with the possibility of lncRNAs as candidate molecules for controlling cancer.

Serum and Glucocorticoid-Inducible Kinase 1 (SGK1) in NSCLC Therapy

Non-small cell lung cancer (NSCLC) remains the most prevalent and one of the deadliest cancers worldwide. Despite recent success, there is still an urgent need for new therapeutic strategies. It is also becoming increasingly evident that combinatorial approaches are more effective than single modality treatments. This review proposes that the serum and glucocorticoid-inducible kinase 1 (SGK1) may represent an attractive target for therapy of NSCLC. Although ubiquitously expressed, SGK1 deletion in mice causes only mild defects of ion physiology. The frequent overexpression of SGK1 in tumors is likely stress-induced and provides a therapeutic window to spare normal tissues. SGK1 appears to promote oncogenic signaling aimed at preserving the survival and fitness of cancer cells. Most importantly, recent investigations have revealed the ability of SGK1 to skew immune-cell differentiation toward pro-tumorigenic phenotypes. Future studies are needed to fully evaluate the potential of SGK1 as a therapeutic target in combinatorial treatments of NSCLC. However, based on what is currently known, SGK1 inactivation can result in anti-oncogenic effects both on tumor cells and on the immune microenvironment. A first generation of small molecules to inactivate SGK1 has already been already produced.