RNA-seq Analysis of Wild-Type vs. FOXC2-Deficient Melanoma Cells Reveals a Role for the FOXC2 Transcription Factor in the Regulation of Multiple Oncogenic Pathways

The FOXC2 Transcription Factor: A Master Regulator of Chemoresistance in Cancer

FOXC2, a member of the forkhead box family of transcription factors, is an emerging oncogene that has been linked to several hallmarks of cancer progression. Among its many oncogenic functions is the promotion of drug resistance, with evidence supporting roles for FOXC2 in escape from broad classes of chemotherapeutics across an array of cancer types. In this Mini-Review, we highlight the current understanding of the mechanisms by which FOXC2 drives cancer chemoresistance, including its roles in the promotion of epithelial-mesenchymal transition, induction of multidrug transporters, activation of the oxidative stress response, and deregulation of cell survival signaling pathways. We discuss the clinical implications of these findings, including strategies for modulating FOXC2-associated chemoresistance in cancer. Particular attention is given to ways in which FOXC2 and its downstream gene products and pathways can be targeted to restore chemosensitivity in cancer cells. In addition, the utility of FOXC2 expression as a predictor of patient response to chemotherapy is also highlighted, with emphasis on the value of FOXC2 as a novel biomarker that can be used to guide therapeutic choice towards regimens most likely to achieve clinical benefit during frontline therapy.

Oncogenic functions of the FOXC2 transcription factor: a hallmarks of cancer perspective

Epigenetic regulation of gene expression is a fundamental determinant of molecular and cellular function, and epigenetic reprogramming in the context of cancer has emerged as one of the key enabling characteristics associated with acquisition of the core hallmarks of this disease. As such, there has been renewed interest in studying the role of transcription factors as epigenetic regulators of gene expression in cancer. In this review, we discuss the current state of knowledge surrounding the oncogenic functions of FOXC2, a transcription factor that frequently becomes dysregulated in a variety of cancer types. In addition to highlighting the clinical impact of aberrant FOXC2 activity in cancer, we discuss mechanisms by which this transcription factor becomes dysregulated in both tumor and tumor-associated cells, placing particular emphasis on the ways in which FOXC2 promotes key hallmarks of cancer progression. Finally, we bring attention to important issues related to the oncogenic dysregulation of FOXC2 that must be addressed going forward in order to improve our understanding of FOXC2-mediated cancer progression and to guide prognostic and therapeutic applications of this knowledge in clinical settings.

The prognostic significance of FOXC2 gene expression in cancer: A comprehensive analysis of RNA-seq data from the cancer genome atlas

The FOXC2 transcription factor is a key regulator of tumor progression in many cancer types. Known to exhibit an array of oncogenic functions when dysregulated, FOXC2 has emerged as a useful biomarker for predicting disease aggression and patient outcome. In this regard, increased expression and nuclear localization of FOXC2 protein in tumor tissue have become well-established as poor prognostic factors for many cancer types. However, whether FOXC2 gene expression can serve as a similarly useful RNA-level biomarker has remained largely unexplored. Therefore, we conducted a comprehensive analysis of TCGA RNA-seq data to evaluate whether FOXC2 gene expression levels in primary tumor biopsies correlate with patient outcome. We report herein that increased expression of FOXC2 RNA in tumor tissue is a poor prognostic factor for patient survival in many cancer types. Moreover, we also found that FOXC2 gene expression predicts cancer patient response to several commonly prescribed chemotherapeutics. Together, these data highlight FOXC2 RNA expression in tumor tissue as an important biomarker with prognostic significance for solid tumors of diverse origin.