is Differentially Expressed Across Breast Cancer Subtypes with Low Expression Associated with Poor Overall Survival.

Purpose: Forkhead box Q1 () has been shown to contribute to the development and progression of cancers, including ovarian and breast cancer (BC). However, research exploring expression, copy number variation (CNV), and prognostic value across different BC subtypes is limited. Our purpose was to evaluate mRNA expression, CNV, and prognostic value across BC subtypes.

Materials And Methods: We determined expression and CNV in BC patient tumors using RT-qPCR and qPCR, respectively. We also analyzed expression and CNV in BC cell lines in the CCLE database using K-means clustering. The prognostic value of expression in the TCGA-BRCA database was assessed using univariate and multivariate Cox's regression analysis as well as using the online tools OncoLnc, GEPIA, and UALCAN.

Results: Our analyses reveal that mRNA is differentially expressed between different subtypes of BC and is significantly decreased in luminal BC and HER2 patients when compared to normal breast tissue samples. Furthermore, analysis of BC cell lines showed that mRNA expression was independent of CNV. Moreover, patients with low mRNA expression had significantly poorer overall survival compared to those with high mRNA expression. Finally, low expression had a critical impact on the prognostic values of BC patients and was an independent predictor of overall survival when it was adjusted for BC subtypes and to two other FOX genes, and .

Conclusion: Our study reveals for the first time that is differentially expressed across BC subtypes and that low expression of is indicative of poor prognosis in patients with BC.