Effect Of CENPF Expression On The Prognosis And Bone Metastasis Of Breast Cancer

Objective:Breast cancer(BC)is one of the most common malignant tumors,ranking first in female tumor deaths.In total,60%to 75%of metastasis in breast cancer leads to bone metastasis.When bone metastasis occurs,the disease enters an incurable stage,with a median survival time of only 2 years,and 5-year survival rates of 20%.However,the underlying mechanism of bone metastasis in breast cancer is not entirely understood,and controlling bone metastasis in breast cancer remains a problem in clinical practice.In previous studies,we found that The Centromere Protein F(CENPF)was highly expressed in breast cancer tissues through breast cancer gene chip and related literatures,which was associated with poor prognosis.No studies have shown that CENPF is associated with bone metastases in breast cancer.Therefore,this study will validate the expression of CENPF in primary breast cancer lesions,bone metastases tissues,lung metastases tissues,and normal breast tissues,and further explore the molecular mechanism of CENPF regulating parathyroid hormone-related peptides(PTHrP)by activating PI3K-AKT-mTORC1 signaling,which provided new therapeutic ideas for predicting and preventing distant metastasis of breast cancer.Methods:1.Using the ONCOMINE database,we compared the expression of CENPF in breast cancer and normal tissues.Findings were confirmed in 60 BC patients through immunohistochemical(IHC)staining.2.Microarray data from GEO and Kaplan-Meier plots were used analyze the overall survival(OS)and relapse free survival(RFS).3.Using the GEO databases,we compared the expression of CENPF in primary lesions,lung metastasis lesions and bone metastasis lesions4.Construct orthotopic breast cancer model,bone metastasis model and lung metastasis model,and immunohistochemically verify the expression level of CENPF in primary lesions,bone metastasis tissues and lung metastasis tissues.5.Based on gene set enrichment analysis(GSEA)and western blot,we predicted the mechanisms by which CENPF regulates BC bone metastasis.Results:1.CENPF is overexpressed in breast and lung cancer(1)From ONCOMINE analysis,CENPF mRNA expression was significantly higher in breast cancer samples compared to normal tissue.Our analysis also demonstrated significantly higher CENPF expression in lung cancer versus normal samples.(2)60 breast cancer samples and paired normal tissue were collected and assessed by immunohistochemistry(IHC)staining.This confirmed that CENPF is expressed to higher levels in breast cancer(42/60,70%)compared to normal tissues(20/60,33.3%).2.High CENPF mRNA expression correlates with poor OS and RFS in breast cancer patientsUsing the public database Kaplan Meier-plotter and the gene chip of the GEO database to analyze the overall survival and relapse-free survival,it was found that the overall survival and relapse-free survival of the high-expression CENPF group were shorter.3.CENPF expression is higher in bone metastasis in BC than that in primary BC lesions and other organs.(1)The GSE2034 is a published dataset consisting of 180 BC specimens without bone metastasis,69 BC specimens with bone metastasis,and 37 BC specimens with other organ metastasis(including lung and brain metastasis).We compared the mRNA expression of CENPF in the 3 types of specimen and found that the expression of CENPF in bone metastasis is higher than primary BC lesions,but does not differ between primary BC lesions and the metastasis of other organs.Through GDS5306 analysis,published datasets consisting of 19 brain metastasis specimens and matched primary breast tumor specimens of 19 BC patients,we also found that the mRNA expression of CENPF does not differ between primary breast tumors and brain metastasis tissue.(2)In the four 4T1 primary BC models and four bone metastasis models of BALB/C mice,CENPF was expressed to higher levels in 75%(3/4)of bone metastasis tissue samples compared to primary lesions and lung metastasis tissues.Interestingly,the expression of PTHrP in these three different tissues showed the same trend as CENPF.However,no significant differences were observed between primary lesions and lung metastatic tissues.4.CENPF regulates the secretion of parathyroid hormone-related peptide(PTHrP)by activating the PI3K-AKT-mTORCl signaling pathway.(1)GSEA analysis revealed a significant association between CENPF and PI3K-AKT-MTOR signaling suggesting a role for these pathways in the metastatic activity of CENPF.(2)By western blot,it was found that the activation of AKT/mTOR signaling pathway and the expression of PTHrP were dramatically inhibited in 4T1 cells with silenced CENPF.(3)Through literature review,we found that activation of mTORC1 can promote the secretion of PTHrP.PTHrP participates in bone remodeling through osteoclastogenesis and facilitates tumor localization and growth in the bone.(4)Using animal models and immunohistochemistry,it was found that the expression of PTHrP in bone metastases tissues was significantly higher than in primary lesions and lung metastases tissues.Conclusion:1.CENPF is highly expressed in breast and lung cancer,and high CENPF expressionis associated with poor prognosis of breast cancer.2.CENPF expression is higher in bone metastasis in BC than that in primary BC lesions and other organs.3.CENPF regulates BC metastasis to bone through PI3K-AKT-mTORC1 signaling.PI3K-AKT-mTORC1 signaling activation results in the increased secretion of PTHrP,and modification of the host osseous environment to promote osteoclast formation and bone colonization.