@article{06c03b8183654fbab03904084b26dd51,
title = "LMTK3 is implicated in endocrine resistance via multiple signaling pathways",
abstract = "Resistance to endocrine therapy in breast cancer is common. With the aim of discovering new molecular targets for breast cancer therapy, we have recently identified LMTK3 as a regulator of the estrogen receptor-alpha (ERα) and wished to understand its role in endocrine resistance. We find that inhibition of LMTK3 in a xenograft tamoxifen (Tam)-resistant (BT474) breast cancer mouse model results in re-sensitization to Tam as demonstrated by a reduction in tumor volume. A whole genome microarray analysis, using a BT474 cell line, reveals genes significantly modulated (positively or negatively) after LMTK3 silencing, including some that are known to be implicated in Tam resistance, notably c-MYC, HSPB8 and SIAH2. We show that LMTK3 is able to increase the levels of HSPB8 at a transcriptional and translational level thereby protecting MCF7 cells from Tam-induced cell death, by reducing autophagy. Finally, high LMTK3 levels at baseline in tumors are predictive for endocrine resistance; therapy does not lead to alteration in levels, whereas in patient's plasma samples, acquired LMTK3 gene amplification (copy number variation) was associated with relapse while receiving Tam. In aggregate, these data support a role for LMTK3 in both innate (intrinsic) and acquired (adaptive) endocrine resistance in breast cancer.",
keywords = "Breast cancer, Endocrine resistance, Estrogen receptor, HSPB8, LMTK3, Oncogene",
author = "J. Stebbing and A. Filipovic and Lit, {L. C.} and K. Blighe and A. Grothey and Y. Xu and Y. Miki and Chow, {L. W.} and Coombes, {R. C.} and H. Sasano and Shaw, {J. A.} and G. Giamas",
note = "Funding Information: We would like to thank Champions Biotechnology, in particular David Sidransky and Elizabeth Bruckheimer for their expertise and help with the mouse xenograft model (Johns Hopkins, Baltimore, USA), P Trivedi for performing the immunohistochemistry staining (Imperial College) and Katsuhiko Ono for technical assistance (Tohoku University). We are grateful to Richard Szydlo (Imperial College) for statistical advice. We thank Martina Sperling for performing the Illumina microarray hybridizations. We thank Luisella Toschi, Anette Sommer, and Georg Beckmann (Bayer, Berlin, Germany) for their significant input in both the experimental design and analysis of the gene expression profiling experiments and the selection of cell lines, without which this work could not have been undertaken. The project was supported by a grant from the Grants for Targets (G4T) program of Bayer Healthcare. JS, JAS, RCC and GG are supported by grants from Cancer Research UK. This work has been supported by a UICC Yamagiwa-Yoshida Memorial International Cancer Study Grant to GG. We thank R & E Girling and friends, Cancer Research UK and the Pink Ribbon Foundation for their support. This work was also supported by the Imperial BRC and ECMC.",
year = "2013",
month = jul,
day = "11",
doi = "10.1038/onc.2012.343",
language = "English",
volume = "32",
pages = "3371--3380",
journal = "Oncogene",
issn = "0950-9232",
publisher = "Nature Publishing Group",
number = "28",
}
