CKS2 and RMI2 are two prognostic biomarkers of lung adenocarcinoma

A combined bioinformatics and experimental approach identifies RMI2 as a Wnt/β-catenin signaling target gene related to hepatocellular carcinoma

BACKGROUND

The Wnt/β-catenin signaling pathway plays an important role in embryogenesis and tumorigenesis. In human cancer, abnormal activity of Wnt/β-catenin signaling pathway induces overexpressed of downstream genes, and initiate oncogene. There are several target genes known to be key players in tumorigenesis, such as c-myc, cyclin D1, MMPs or survivin. Therefore, identifying the target genes of Wnt/β-catenin signaling pathway is important to understanding Wnt/β-catenin-mediated carcinogenesis. In this study, we developed a combined bioinformatics and experimental approach to find potential target genes.

METHODS

Luciferase reporter assay was used to analyze the promoter activity of RMI2. WST1 cell proliferation assays and transwell assays were performed to determine the proliferation and migration capacities of RMI2 overexpressing or knockdown stable hepatic cells. Finally, xenograft experiments were performed to measure the tumor formation capacity in vivo.

RESULTS

The results showed that RMI2 mRNA was upregulated after LiCl treatment and Wnt3a-conditioned medium in a culture of SK-hep-1 cell lines. A chromatin immunoprecipitation (ChIP) assay showed that the β-catenin/T cell-specific factor (TCF) complex binds to the putative TCF binding site of the RMI2 promoter. We then found a TCF binding site at - 333/- 326 of the RMI2 promoter, which is crucial for β-catenin responsiveness in liver cell lines. RMI2 was overexpressed in hepatoma tissue and cell lines, and it promoted the migration and invasion of HCC cells. Moreover, RMI2 upregulated the expression of epithelial-mesenchymal transition (EMT) markers and the Wnt3a/β-catenin-related genes, but silencing RMI2 had the opposite effects. Notably, the expression of RMI2 was positively correlated with the clinical data of HCC patients who had significantly shorter overall survival (OS) and disease-free survival (DFS) (Both: P < 0.05). In addition, a total of 373 HCC patients' data from the Caner Genome Atlas project (TCGA) were used to validate our findings.

CONCLUSIONS

Taking all these findings together, we determined that RMI2 was a new target gene of the Wnt/β-catenin signaling pathway. We also found that RMI2 promotes EMT markers, HCC cell invasion, and metastasis, which indicated that RMI2 is a potential target for preventing or at least mitigating the progression of HCC.

Knockdown of DLK4 inhibits non-small cell lung cancer tumor growth by downregulating CKS2

Non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases and is considered as the most common type of cancer. DLX4 was originally identified as a β-globin gene suppressor in red blood cells, which plays critical roles in several types of cancers. However, the role and related mechanism of DLX4 in NSCLC are still unclear. The study aimed to uncover the expression of DLX4 in human NSCLC cells and tissues, reveal its possible role in NSCLC, and investigate the underlying mechanisms. Immunoblot and TCGA database were used to detect the expression of DLX4 in human NSCLC cells and tissues. CCK-8, colony formation, and FCM assays were conducted to detect the effects of DLX4 on the viability and cell cycle of NCI-H2170 and A549 cells. Immunoblot assays were further performed to investigate the possible mechanism underlying DLX4 affecting the growth of NSCLC. We revealed that knockdown of DLX4 inhibited NSCLC cell proliferation. We further revealed that DLX4 knockdown induced the NSCLC cell cycle arrest. Our results further showed that downregulation of DLX4 suppressed YB-1 expression, which further suppressed CKS2 expression, thereby suppressing tumor growth of NSCLC. In conclusion, DLX4 has the potential to serve as a promising drug for NSCLC treatment.

RMI2 is a novel prognostic and predictive biomarker for breast cancer

BACKGROUND

RecQ-mediated genome instability 2 (RMI2) maintains genome stability by promoting DNA damage repair. It has been reported to accelerate the progression of several tumors. However, the functional mechanism of RMI2 in breast cancer remains unclear.

METHODS

Gene expression profiles were obtained from TCGA, GTEx, and GEO databases. The expression of RMI2 and its prognostic value in breast cancer was explored. In addition, we calculated pooled standardized mean deviation (SMD) and performed a summary receiver operating characteristic (sROC) curve analysis to further determine RMI2 expression status and diagnostic significance. The functions and related signaling pathways were investigated based on GO and KEGG analyses. The PPI network was constructed by combining the STRING database and Cytoscape software. Subsequently, in vitro assays were conducted to detect the effect of RMI2 on the proliferation and migration of breast cancer cells.

RESULTS

The expression of RMI2 was markedly upregulated in breast cancer tissues relative to that in normal tissues. Moreover, pooled SMD further confirmed the overexpression of RMI2 in breast cancer (SMD = 1.29, 95% confidence interval (CI): 1.18-1.41, p = 0.000). The sROC curve analysis result suggested that RMI2 had a relatively high diagnostic ability in breast cancer (AUC = 0.87, 95% CI: 0.84-0.90). High RMI2 expression was associated with poor prognosis. GO and KEGG analyses revealed that RMI2 was closely related to cell adhesion, various enzyme activities, and PI3K/AKT signaling pathway. PPI analysis showed that RMI2 had interactions with proteins involved in DNA damage repair. knockdown of RMI2 remarkably inhibited the proliferation and migration of breast cancer cells, while overexpression of RMI2 exerted the opposite effects. Furthermore, we identified that RMI2 accelerates the proliferation and migration of breast cancer cells via activation of the PI3K/AKT pathway.

CONCLUSION

The results suggest that RMI2 is a potential diagnostic and prognostic biomarker associated with cell proliferation and migration, and may be used as a novel therapeutic target for breast cancer in the future.

Cyclin-Dependent Kinase Subunit 2 (CKS2) as a Prognostic Marker for Stages I-III Invasive Non-Mucinous Lung Adenocarcinoma and Its Role in Affecting Drug Sensitivity

With the aim of improving the prognosis of patients with lung adenocarcinoma (LUAD), we identified the biomarker related to the sensitivity of patients to chemotherapy drugs and explored the potential mechanisms. As a cell cycle-related protein, CKS2 has an essential role to play in tumor progression and prognosis. CKS2 expression was measured using TCGA RNA-sequencing data and immunohistochemistry. The sensitivity data of tumor cells to chemotherapeutic drugs for lung cancer was acquired from the Cancer Therapeutics Response Portal (CTRP) database. A range of bioinformatics methods was used to explore the mechanisms of CKS2 upregulation. The biological functions of CKS2 were predicted using GO and KEGG enrichment analysis, as well as GSEA. CKS2 expression was up-regulated in stages I-III invasive non-mucinous lung adenocarcinoma and varied significantly between various histological subtypes. High CKS2 expression worsened the prognosis of patients. The CKS2 expression level was linked to the sensitivity of LUAD cells to carboplatin and paclitaxel. CKS2 upregulation was associated with the immune microenvironment, mRNA methylation, and competing endogenous RNAs (ceRNAs). CKS2 can serve as a diagnostic and prognostic biomarker for stages I-III invasive non-mucinous lung adenocarcinoma and modulate the effect of paclitaxel and carboplatin by regulating microtubule binding and influencing carboplatin binding to DNA.

Comprehensive Expression Profiling and Molecular Basis of CDC28 Protein Kinase Regulatory Subunit 2 in Cervical Cancer

More and more evidence suggests the oncogenic function of overexpressed CDC28 protein kinase regulatory subunit 2 (CKS2) in various human cancers. However, CKS2 has rarely been studied in cervical cancer. Herein, taking advantage of massive genetics data from multicenter RNA-seq and microarrays, we were the first group to perform tissue microarrays for CKS2 in cervical cancer. We were also the first to evaluate the clinical significance of CKS2 with large samples (980 cervical cancer cases and 422 noncancer cases). We further excavated the mechanism of the tumor-promoting activities of CKS2 in cervical cancer through analysis of genetic mutation profiles, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) significant enrichment of genes coexpressed with CKS2. According to the results, expression data from multilevels unanimously supported the overexpression of CKS2 in cervical cancer. Patients with cervical cancer in stage II from inhouse microarrays had significantly higher expression of CKS2, and CKS2 overexpression had an adverse impact on the disease-free survival status of cervical cancer patients in GSE44001. Both mutation types of mRNA high and mRNA low appeared in cervical cancer cases from the TCGA Firehose project. Gene coexpressed with CKS2 participated in pathways including the cell cycle, estrogen signaling pathway, and DNA replication. In summary, upregulated CKS2 is closely associated with the malignant clinical development of cervical cancer and might serve as a valuable therapeutic target in cervical cancer.

Knockdown of replication protein A 3 induces protective autophagy and enhances cisplatin sensitivity in lung adenocarcinoma by inhibiting AKT/mTOR signaling via binding to cyclin-dependent kinases regulatory subunit 2

Replication protein A 3 (RPA3) is a significant component of replication protein A and has been documented to function as an oncogene in several types of cancers. However, the role and underlying mechanism of RPA3 in lung adenocarcinoma (LUAD) remains unknown. In this study, messenger expression of RPA3 and survival probability in LUAD were predicted by the UALCAN database. The combination of RPA3 with cyclin-dependent kinases regulatory subunit 2 (CKS2) were characterized by the humanbase and STRING databases and verified by co-immunoprecipitation. Cell viability was assessed by Cell Counting Kit-8 assay and colony formation assay. Flow cytometric analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay were used to determine cell cycle and cell apoptosis, respectively. The expressions of protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway and autophagy-related proteins were examined by western blot assay. Significantly, we revealed that RPA3 expression was upregulated in LUAD and is associated with poor prognosis in LUAD patients. RPA3 and CKS2 expression was highly expressed in LUAD cell lines and the interaction between RPA3 and CKS2 was confirmed. RPA3 silencing inhibited A549 cell viability, blocked cell cycle and promoted cell apoptosis, as well as induction of autophagy and inhibition of AKT/mTOR signaling. CKS2 overexpression reversed the effects of RPA3 silencing on A549 cells. In addition, RPA3 knockdown enhanced cisplatin sensitivity of A549 cells through blocking the AKT/mTOR signaling. These results suggested that RPA3 might control LUAD cell autophagy and enhance cisplatin sensitivity by regulation of AKT/mTOR signaling via targeting CKS2.

Expression Profile and Molecular Basis of Cyclin-Dependent Kinases Regulatory Subunit 2 in Endometrial Carcinoma Detected by Diversified Methods

Purpose: Our purpose was to systematically appraise the clinicopathological significance and explore the molecular bases of CKS2 in endometrial carcinoma. Patients and Methods: We measured the clinicopathological significance of CKS2 using diverse methods of public RNA-seq, microarrays, and in-house tissue microarrays to investigate the molecular basis of CKS2 in endometrial carcinoma through upstream transcriptional analysis, immune infiltration correlation analysis, and co-expression analysis. Results: Both the analysis for public RNA-seq plus the microarray data and in-house tissue microarray confirmed the significant overexpression of CKS2 in a total of 1,021 endometrial carcinoma samples compared with 279 non-cancer endometrium samples (SMD = 2.10, 95% CI = 0.72-3.48). The upregulated CKS2 was significantly related to the lymph node metastasis and advanced clinical grade of endometrial carcinoma patients (p < 0.001). Mutation types such as amplification and mRNA occurred with high frequency in the CKS2 gene in endometrial carcinoma patients. A series of miRNAs and transcription factors, such as hsa-miR-26a, hsa-miR-130a, hsa-miR-30, E2F4, MAX, and GABPA, were predicted to regulate the transcription and expression of CKS2. Significant links were found between CKS2 expression and the infiltration level of B cells, CD4⁺ T cells, and neutrophils in endometrial carcinoma. CKS2-coexpressed genes were actively involved in pathways such as the mitotic cell cycle process, PID aurora B pathway, and prolactin signaling pathway. Conclusion: The overexpressed CKS2 showed positive correlations with the clinical progression of endometrial carcinoma and was associated with various cancer-related biological processes and pathways, showing potential as a promising clinical biomarker for endometrial carcinoma.

The Clinical Significance of RMI2 in Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC), which is the most common type of primary liver cancer, often presents at advanced stage with a dismal prognosis. Novel tumor biomarkers are needed to aid in HCC early detection and prognostication. Methods: Immunohistochemical staining for RecQ-mediated genome instability protein 2 (RMI2) was performed in 330 surgically resected HCC specimens and 190 adjacent normal tissues. Univariate and multivariate regression analysis were applied to identify prognostic indicators of HCC outcomes. Patient's survival was assessed with the Kaplan-Meier method. Results: RMI2 in HCC tissue was significantly higher than that in adjacent normal tissues, and was positively correlated with HCC histological grade and stage (P < .05) but negatively correlated with the survival period. RIM2 was identified to be an independent prognostic indicator for HCC. Conclusion: The abnormal expression of RMI2 may be related to the occurrence and development of HCC. RIM2 could potentially serve as a novel tumor-specific biomarker for HCC diagnosis and prognosis prediction.

CKS2 Promotes the Growth in Non-Small-Cell Lung Cancer by Downregulating Cyclin-Dependent Kinase Inhibitor

INTRODUCTION/OBJECTIVE

This study aimed to explore the expression of cyclin-dependent kinase subunit 2 (CKS2) in tissues and cells in non-small-cell lung cancer (NSCLC) and the function mechanism of CKS2 in NSCLC cell growth and tumorigensis.

METHODS

After transfecting NCI-H2170 cells with short-hair RNA (shRNA), an shCKS2 gene-silencing model was established. The cells were divided into a shRNA group and shNC group. For overexpression cell lines, we used the same method to establish the NCI-H2170-CKS2 cell lines. Cell Count Kit-8 assay and colony formation assay were used to determine cell viability and cell growth, respectively. Propidium iodide staining was used to determine cell cycle progression. The mRNA expression of CKS2 and protein expression of CKS2, p21, p53, and PTEN were determined by RT-qPCR and Western blotting, respectively. The expression of CKS2, p53, and Ki67 in tissues was determined by immunohistochemical stain. The in vivo tumorigenesis assays were used to determine the ability of CKS2 in tumor growth.

RESULTS

The results of RT-qPCR and Western blotting assay revealed that CKS2 upregulated expression in NSCLC tissues and cells. The results of the CCK-8 assay revealed that the shRNA group exhibited significantly lower cell viability and foci formation than the empty plasmid group, while CKS2 overexpression induces cell growth and cell cycle progression. The result of nude mice suggested that CKS2 knockdown expression suppressed tumorigenesis in the in vivo animal model.

CONCLUSIONS

Our study suggests that CKS2 could be a biomarker in the progression and prognosis of NSCLC.

RMI2 is a prognostic biomarker and promotes tumor growth in hepatocellular carcinoma

Genomic instability is a hallmark of all cancers. RMI2 is a crucial component of the BLM-TopoIIIa-RMI1-RMI2 complex that maintains genome stability. It has been shown to accelerate tumor progression in lung cancer, cervical cancer, and prostate cancer. However, its expression and function in hepatocellular carcinoma (HCC) remain poorly defined. In this study, gene expression data and corresponding clinical information of HCC were downloaded from the TCGA, ICGC, and GEO databases. The expression level and clinical significance of RMI2 in HCC were then analyzed. In addition, cellular and molecular biology experiments were conducted to explore the effects of silencing and overexpression of RMI2 on human liver cancer cells and the associated mechanisms. The results showed that RMI2 expression was elevated in HCC tissues. High expression of RMI2 was correlated with shorter survival and poor prognosis of patients. The results of CCK-8, Edu, and clonogenic assays confirmed that RMI2 overexpression promoted the proliferation of HCC cells. Flow cytometric analysis demonstrated that RMI2 overexpression enhanced G1-S phase transition and decreased apoptosis. Moreover, the protein expression of key effector molecules in the p53 signaling pathway was reduced following RMI2 overexpression. In summary, these results indicate that RMI2 promotes the growth of HCC cells and suppresses their apoptosis by inhibiting the p53 signaling pathway. This study provides new insights into the mechanisms driving HCC tumorigenesis and new therapeutic targets.