High expression of <i>ubiquitin carboxy‐terminal hydrolase‐L1</i> and <i>‐L3</i> mRNA predicts early recurrence in patients with invasive breast cancer

Abstract

The present study investigated the mRNA expression level of ubiquitin c-terminal hydrolase (UCH)-L1 and -L3 in breast cancer tissue and aimed to elucidate its association with tumor characteristics and patient prognosis. UCH-L1 and UCH-L3 mRNA levels in invasive breast cancer (n = 100) were determined by a real-time polymerase chain reaction (PCR) assay and their relationship with various clinicopathological characteristics of breast tumors as well as patient prognosis were studied. UCH-L3 mRNA level was significantly upregulated in breast cancer tissue compared to adjacent normal breast tissue (P < 0.005), and UHC-L1 mRNA level also showed a non-significant increase in tumor tissue compared to adjacent normal breast tissue. Both UCH-L1 and UCH-L3 mRNA levels were significantly higher in high histological grade tumors than in low histological grade tumors (P < 0.001 and P < 0.005, respectively). High UCH-L1 mRNA level was significantly associated with negative estrogen receptor status (P < 0.05) and negative progesterone receptor status (P < 0.05). Patients with both UCH-L1 and UCH-L3 mRNA high tumors showed a significantly poorer prognosis than those in the UCH-L1 or UCH-L3 mRNA low group (P < 0.005). These observations that UCH-L3 mRNA level is upregulated in breast cancer tissue, and breast tumors with both UCH-L1 and UCH-L3 mRNA high expression are associated with a poor prognosis, suggest the possible involvement of UCH-L1 and UCH-L3 in the pathogenesis and progression of breast cancer.