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

Abstract

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.

Keywords: CKS2; RNA-seq; endometrial carcinoma; in-house tissue microarray; molecular mechanism.

FIGURE 1

Flowchart of inclusion of eligible microarrays and RNA-seq datasets.

FIGURE 2

CKS2 expression in endometrial carcinoma and non-cancer samples from external microarrays and RNA-seq dataset. Violin plots for GSE115810 (A), GSE146889 (B), GSE17025 (C), GSE56087 (D), GSE63678 (E) and TCGA-GTEx dataset (F). N, non-cancer endometrium samples; T, endometrial carcinoma samples.

FIGURE 3

Pooling results of CKS2 expression in endometrial carcinoma and non-cancer tissues for in-house tissue microarray, public microarrays, and RNA-seq datasets. (A) SMD forest. (B) SROC curves.

FIGURE 4

The clinicopathological significance of CKS2 expression in endometrial carcinoma from the RNA-seq dataset. (A) The remarkable differential expression of CKS2 between endometrial carcinoma patients of lower grade and higher grade. (B) Expression pattern of CKS2 in different race groups of endometrial carcinoma patients. (C) Kaplan-Meier survival curves of the overall survival probability of endometrial carcinoma patients.

FIGURE 5

IHC staining of CKS2 in endometrial carcinoma and non-cancer tissues from in-house tissue microarrays. (A) Strong staining of CKS2 in endometrial carcinoma tissues (Left: ×200; Right: ×400); (B) Strong staining of CKS2 in endometrial carcinoma tissues (Left: ×200; Right: ×400); (C) Weak staining of CKS2 in non-cancer endometrium tissues (Left: ×200; Right: ×400); (D) Weak staining of CKS2 in non-cancer endometrium tissues (Left: ×200; Right: ×400); (E) Violin plot of CKS2 expression in endometrial carcinoma and non-cancer endometrium tissues. (F) ROC curves of the discriminating ability of CKS2 expression for endometrial carcinoma. N, non-cancer endometrium samples. T, endometrial carcinoma samples.

FIGURE 6

The relationship between CKS2 expression and the tumor purity or infiltration level of diverse immune cells in endometrial carcinoma. TPM: transcripts per million.

FIGURE 7

Co-expressed genes of CKS2 and functional annotations for genes positively correlated with CKS2 in endometrial carcinoma. (A) Venn plot for genes positively co-expressed with CKS2 in endometrial carcinoma. (B). Venn plot for genes negatively co-expressed with CKS2 in endometrial carcinoma. (C). Network of enriched terms for positively co-expressed genes colored by cluster ID. (D). Network of enriched terms for positively co-expressed genes colored by p-value.