High expression of LMTK3 is an independent factor indicating a poor prognosis in estrogen receptor α-positive breast cancer patients.

Abstract

OBJECTIVE:

Over 70% of breast cancers are estrogen receptor alpha-positive, and endocrine therapy targeting estrogen action decreases mortality from breast cancer. Recently, a novel protein kinase that regulates estrogen receptor alpha activity, lemur tyrosine kinase-3, has been identified. In this study, we investigated whether messenger RNA expression and polymorphisms of the gene encoding the kinase, LMTK3, are associated with prognosis in breast cancer patients during long-term follow-up.

METHODS:

First, we investigated the relationship between messenger RNA expression of LMTK3 and patient outcome in 219 breast cancers. The effects of several variables on survival were tested by Cox proportional hazards regression analysis. Next, we performed LMTK3 genotyping in 471 breast cancers to clarify the prognostic role of these polymorphisms.

RESULTS:

Our data showed that LMTK3 expression level was not associated with prognosis in all patients. We then analyzed the impact of LMTK3 mRNA expression on the prognosis of breast cancer according to estrogen receptor alpha status. Both disease-free survival and overall survival were significantly shorter in estrogen receptor alpha-positive patients with high LMTK3 expression receiving adjuvant endocrine therapy than in those patients with low LMTK3 expression. Multivariate Cox regression analysis revealed that high LMTK3 expression was an independent poor prognostic factor in estrogen receptor alpha-positive breast cancer patients. We did not find any correlation between LMTK3 genotypes and prognosis of breast cancer patients in our series.

CONCLUSIONS:

Our results show that high expression of LMTK3 is an independent prognostic factor in estrogen receptor alpha-positive breast cancer patients receiving adjuvant endocrine therapy.

• Authors: Tomoko Asano, Shinya Sato, Nobuyasu Yoshimoto, Yumi Endo, Yukari Hato, Yu Dong, Satoru Takahashi, Yoshitaka Fujii, Tatsuya Toyama
• Journal: Japanese journal of clinical oncology (Jpn J Clin Oncol) Vol. 44 Issue 10 Pg. 889-97 (Oct 2014) ISSN: 1465-3621 [Electronic] England
• PMID: 25163465 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected].

Chemical References

• Biomarkers, Tumor
• ESR1 protein, human
• Estrogen Receptor alpha
• Membrane Proteins
• RNA, Messenger
• Receptors, Progesterone
• ERBB2 protein, human
• Receptor, ErbB-2
• LMTK3 protein, human
• Protein Serine-Threonine Kinases

Topics

• Adult
• Biomarkers, Tumor (analysis)
• Breast Neoplasms (chemistry, metabolism, pathology)
• Carcinoma, Ductal, Breast
• Disease-Free Survival
• Estrogen Receptor alpha (analysis, metabolism)
• Female
• Gene Expression Regulation, Neoplastic
• Genotype
• Humans
• Immunohistochemistry
• Kaplan-Meier Estimate
• Membrane Proteins (analysis, genetics, metabolism)
• Middle Aged
• Polymorphism, Single Nucleotide
• Predictive Value of Tests
• Prognosis
• Proportional Hazards Models
• Protein Serine-Threonine Kinases (analysis, genetics, metabolism)
• RNA, Messenger (metabolism)
• Real-Time Polymerase Chain Reaction
• Receptor, ErbB-2 (analysis)
• Receptors, Progesterone (analysis)
• Signal Transduction
• Up-Regulation