Hu-antigen R (HuR) is an RNA-binding post-transcriptional regulator that belongs to the Hu/ELAV
family. HuR expression levels are modulated by a variety of proteins, microRNAs, chemical
compounds or the microenvironment and in turn HuR affects mRNA stability and translation of
various genes implicated in breast cancer formation, progression, metastasis and treatment. The aim
of the present review is to critically summarise the role of HuR in breast cancer development and its
potential as a prognosticator and a therapeutic target. In this aspect, all the existing English
literature concerning HuR expression and function in breast cancer cell lines, in vivo animal models
and clinical studies is critically presented and summarized. HuR modulates many genes implicated in
biological processes crucial for breast cancer formation, growth and metastasis, while the link
between HuR and these processes has been demonstrated directly in vitro and in vivo. Additionally,
clinical studies reveal that HuR is associated with more aggressive forms of breast cancer and is a
putative prognosticator for patients’ survival. All the above indicate HuR as a promising drug target
for cancer therapy; nevertheless, additional studies are required to fully understand its potential and
determine against which types of breast cancer and at which stage of the disease a therapeutic
agent targeting HuR would be more effective.