Lemur tyrosine kinase-3 (LMTK3) as a target in oestrogen positive breast cancer

Abstract

Oestrogen receptor positive (ER⁺) breast cancers are susceptible to endocrine treatments, such as tamoxifen. However, resistance is a major problem when treating breast cancer with these agents. ERα phosphorylation is implicated in this resistance to tamoxifen, and kinases are the enzymes that catalyse phosphorylation. A kinome search in human breast cancer cells identified lemur tyrosine kinase 3 (LMTK3). In primary breast cancer samples, high nuclear LMTK3 expression was associated with a shorter disease-free survival time. In tamoxifen-resistant cell lines, the addition of LMTK3 siRNA, increased the inhibitory effect of tamoxifen. In nude mice, with established human MCF-7 breast cancer tumours, LMTK3 siRNA decreased tumour growth. In conclusion, LMKT3 is a possible target and marker of breast cancer.

Keywords:

• breast cancer
• breast cancer marker
• breast cancer target
• endocrine treatment
• lemur tyrosine kinase-3 (LMTK3)
• tamoxifen