Coordinate Hyperactivation of Notch1 and Ras/MAPK Pathways Correlates with Poor Patient Survival: Novel Therapeutic Strategy for Aggressive Breast Cancers

Mittal, Suruchi and Sharma, Ankur and Balaji, Sai A and Gowda, Manju C and Dighe, Rajan R and Kumar, Rekha V and Rangarajan, Annapoorni (2014) Coordinate Hyperactivation of Notch1 and Ras/MAPK Pathways Correlates with Poor Patient Survival: Novel Therapeutic Strategy for Aggressive Breast Cancers. In: MOLECULAR CANCER THERAPEUTICS, 13 (12). pp. 3198-3209.

PDF mol_can_the_13-12_3198_2014.pdf - Published Version Restricted to Registered users only Download (930kB) | Request a copy

Abstract

Aberrant activation of Notch and Ras pathways has been detected in breast cancers. A synergy between these two pathways has also been shown in breast cell transformation in culture. Yet, the clinical relevance of Notch-Ras cooperation in breast cancer progression remains unexplored. In this study, we show that coordinate hyperactivation of Notch1 and Ras/MAPK pathways in breast cancer patient specimens, as assessed by IHC for cleaved Notch1 and pErk1/2, respectively, correlated with early relapse to vital organs and poor overall survival. Interestingly, majority of such Notch1 (high)Erk(high) cases encompassed the highly aggressive triple-negative breast cancers (TNBC), and were enriched in stem cell markers. We further show that combinatorial inhibition of Notch1 and Ras/MAPK pathways, using a novel mAb against Notch1 and a MEK inhibitor, respectively, led to a significant reduction in proliferation and survival of breast cancer cells compared with individual inhibition. Combined inhibition also abrogated sphere-forming potential, and depleted the putative cancer stem-like cell subpopulation. Most importantly, combinatorial inhibition of Notch1 and Ras/MAPK pathways completely blocked tumor growth in a panel of breast cancer xenografts, including the TNBCs. Thus, our study identifies coordinate hyperactivation of Notch1 and Ras/MAPK pathways as novel biomarkers for poor breast cancer outcome. Furthermore, based on our preclinical data, we propose combinatorial targeting of these two pathways as a treatment strategy for highly aggressive breast cancers, particularly the TNBCs that currently lack any targeted therapeutic module. (C) 2014 AACR.

Item Type:	Journal Article
Publication:	MOLECULAR CANCER THERAPEUTICS
Additional Information:	Copyright for this article belongs to the AMER ASSOC CANCER RESEARCH, 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA 19106-4404 USA
Department/Centre:	Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Date Deposited:	18 Jan 2015 06:30
Last Modified:	18 Jan 2015 06:30
URI:	http://eprints.iisc.ac.in/id/eprint/50685

Actions (login required)

View Item