The clinical significance of the expression of PROM1/CD133, NOTCH2 and CDK4 in triple-negative breast cancer
Authors: Zhang Pingping , Dong Qiuli , Zhang Ying , Hu Qiongbi , Zhang Zhuo , Mao Weifeng , Qi Wenjing , Yang Yanqin , Yang Zhiqiang 
Published: December 2023

Abstract
Purpose:The aim of this study is to investigate the expression of cyclin kinase 4 (CDK4), PROM1/CD133 (CSC marker), and NOTCH2 proteins in triple negative breast cancer (TNBC), and to determine their correlation with clinicopathological parameters and survival prognosis. Additionally, we aim to explore the prognostic value of co-expression in TNBC.
Method:In this study, we utilized the GEPIA database to analyze the differential expression of genes CDK4, NOTCH2, and PROM1/CD133. Furthermore, we investigated the relationship between these target genes and various clinical factors such as patient age, TNM stage, metastasis, and prognosis using data from the TCGA database. We also examined changes in CDK4, NOTCH2, and PROM1/CD133 protein levels by analyzing datasets from the CPTAC and HPA databases. To evaluate the prognostic value of CDK4, NOTCH2, and PROM1/CD133 expression levels in TNBC patients, we employed Kaplan-Meier survival analysis. Additionally, we constructed a protein-protein interaction network (PPI) and performed pathway enrichment analysis using the STRING database.In this study, Kaplan-Meier survival analysis and Cox proportional hazards regression were conducted on a sample of 48 patients with triple-negative breast cancer (TNBC) who had been evaluated for the expression of CDK4, NOTCH2, and PROM1/CD133 using immunohistochemical methods. The expression intensity of these three proteins was assessed using Image-Pro Plus 6.0 image analysis software.
Results:Using data mining, we found that compared with normal breast tissue, CDK4、
PROM1/CD133 mRNA and protein levels were up-regulated in TNBC, but NOTCH2
was up-regulated at the mRNA level and down-regulated at the transcriptional level. In TNBC patients, the high expression of NOTCH2 was related to the histological
grade of the patients (p=0.024), and the expression level was related to the survival outcome of the patients. The high expression of CDK4 correlated with the patient's age (p=0.036). PROM1/CD133 expression was significantly correlated with OS (p = 0.005), CDK4 expression was not statistically significantly different in OS, an
NOTCH2 expression was significantly different in OS (p = 0.078), but did not reach statistical significance.We found correlations between NOTCH2, CDK4, and PROM1/CD133 genes shown in the TCGA database and our validation cohort. When PROM1/CD133 and NOTCH2 were used as prognostic joint markers, it was found that the PROM1/CD133 high expression NOTCH2 low expression group had a significantly decreased survival rate.
Conclusion:Using data mining analysis and validation with our clinical cohort, PROM1/CD133 was proved to be an independent prognostic biomarker for TNBC, especially when PROM1/CD133 and NOTCH2 were combined markers were significantly associated with the prognosis of patients. Further studies are needed to verify the potential clinical application of these two targeted therapies for TNBC.