Header

UZH-Logo

Maintenance Infos

Breast tumor kinase (Brk/PTK6) is a mediator of hypoxia- associated breast cancer progression


Anderson, T M R; Peacock, D L; Daniel, A R; Hubbard, G K; Lofgren, K A; Girard, B J; Schoerg, A; Hoogewijs, D; Wenger, R; Seagroves, T N; Lange, C A (2013). Breast tumor kinase (Brk/PTK6) is a mediator of hypoxia- associated breast cancer progression. Cancer Research, 73(18):5810-5826.

Abstract

Basal-type triple-negative breast cancers (TNBC) are aggressive and difficult to treat relative to luminal-type breast cancers. TNBC often express abundant Met receptors and are enriched for transcriptional targets regulated by hypoxia-inducible factor-1α (HIF-1α), which independently predict cancer relapse and increased risk of metastasis. Brk/PTK6 is a critical downstream effector of Met signaling and is required for hepatocyte growth factor (HGF)-induced cell migration. Herein, we examined the regulation of Brk by HIFs in TNBC in vitro and in vivo. Brk mRNA and protein levels are upregulated strongly in vitro by hypoxia, low glucose, and reactive oxygen species. In HIF-silenced cells, Brk expression relied upon both HIF-1α and HIF-2α, which we found to regulate BRK transcription directly. HIF-1α/2α silencing in MDA-MB-231 cells diminished xenograft growth and Brk reexpression reversed this effect. These findings were pursued in vivo by crossing WAP-Brk (FVB) transgenic mice into the MET(Mut) knockin (FVB) model. In this setting, Brk expression augmented MET(Mut)-induced mammary tumor formation and metastasis. Unexpectedly, tumors arising in either MET(Mut) or WAP-Brk × MET(Mut) mice expressed abundant levels of Sik, the mouse homolog of Brk, which conferred increased tumor formation and decreased survival. Taken together, our results identify HIF-1α/2α as novel regulators of Brk expression and suggest that Brk is a key mediator of hypoxia-induced breast cancer progression. Targeting Brk expression or activity may provide an effective means to block the progression of aggressive breast cancers. Cancer Res; 73(18); 5810-20. ©2013 AACR.

Abstract

Basal-type triple-negative breast cancers (TNBC) are aggressive and difficult to treat relative to luminal-type breast cancers. TNBC often express abundant Met receptors and are enriched for transcriptional targets regulated by hypoxia-inducible factor-1α (HIF-1α), which independently predict cancer relapse and increased risk of metastasis. Brk/PTK6 is a critical downstream effector of Met signaling and is required for hepatocyte growth factor (HGF)-induced cell migration. Herein, we examined the regulation of Brk by HIFs in TNBC in vitro and in vivo. Brk mRNA and protein levels are upregulated strongly in vitro by hypoxia, low glucose, and reactive oxygen species. In HIF-silenced cells, Brk expression relied upon both HIF-1α and HIF-2α, which we found to regulate BRK transcription directly. HIF-1α/2α silencing in MDA-MB-231 cells diminished xenograft growth and Brk reexpression reversed this effect. These findings were pursued in vivo by crossing WAP-Brk (FVB) transgenic mice into the MET(Mut) knockin (FVB) model. In this setting, Brk expression augmented MET(Mut)-induced mammary tumor formation and metastasis. Unexpectedly, tumors arising in either MET(Mut) or WAP-Brk × MET(Mut) mice expressed abundant levels of Sik, the mouse homolog of Brk, which conferred increased tumor formation and decreased survival. Taken together, our results identify HIF-1α/2α as novel regulators of Brk expression and suggest that Brk is a key mediator of hypoxia-induced breast cancer progression. Targeting Brk expression or activity may provide an effective means to block the progression of aggressive breast cancers. Cancer Res; 73(18); 5810-20. ©2013 AACR.

Statistics

Citations

17 citations in Web of Science®
23 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

48 downloads since deposited on 25 Sep 2013
17 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Institute of Physiology
07 Faculty of Science > Institute of Physiology

04 Faculty of Medicine > Center for Integrative Human Physiology
Dewey Decimal Classification:570 Life sciences; biology
610 Medicine & health
Language:English
Date:2013
Deposited On:25 Sep 2013 06:36
Last Modified:07 Dec 2017 22:37
Publisher:American Association for Cancer Research
ISSN:0008-5472
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1158/0008-5472.CAN-13-0523
PubMed ID:23928995

Download

Download PDF  'Breast tumor kinase (Brk/PTK6) is a mediator of hypoxia- associated breast cancer progression'.
Preview
Content: Accepted Version
Filetype: PDF
Size: 679kB