Effect of Cellular Senescence on the Growth of HER2-Positive Breast Cancers
- Mariano F. Zacarias-Fluck,
- Beatriz Morancho,
- Rocio Vicario,
- Antonio Luque Garcia,
- Marta Escorihuela,
- Josep Villanueva,
- Isabel T. Rubio and
- Joaquín Arribas
+Author Affiliations
- Correspondence to: Joaquín Arribas, PhD, Psg. Vall d’Hebron 119-129, Barcelona 08035, Spain (e-mail: jarribas@vhio.net).
- Received August 12, 2014.
- Revision received December 4, 2014.
- Accepted January 20, 2015.
Abstract
Background: Oncogene-induced senescence (OIS) is a tumor suppressor mechanism. However, senescent cells remain viable and display a distinct secretome (also known as senescence-associated secretory phenotype [SASP] or senescence messaging secretome, [SMS]) that, paradoxically, includes protumorigenic factors. OIS can be triggered by ectopic overexpression of HER2, a receptor tyrosine kinase and the driving oncogene in a subtype of human breast cancer. However, cellular senescence has not been characterized in HER2-positive tumors.
Methods: Using an approach based on their inability to proliferate, we isolated naturally occurring senescent cells from a variety of tumor models including HER2-positive cells, transgenic mice (n = 3), and patient-derived xenografts (PDXs) (n = 6 mice per group from one PDX derived from one patient). Using different biochemical and cell biological techniques, we characterized the secretome of these senescent cells. All statistical tests were two-sided.
Results: We found that senescent cells arise constantly in different models of advanced breast cancers overexpressing HER2 and constitute approximately 5% of tumor cells. In these models, IL-6 and other cytokines were expressed mainly, if not exclusively, by the naturally occurring senescent cells (95.1% and 45.0% of HCC1954 cells and cells from a HER2-positive PDX expressing a senescent marker expressed IL-6, respectively). Furthermore, inhibition of IL-6 impaired the growth of the HER2-positive PDX (mean tumor volume at day 101, control vs anti–huIL-6 treated, 332.2mm3 [95% confidence interval {CI} = 216.6 to 449.8] vs 114.4mm3 [95% CI = 12.79 to 216.0], P = .005).
Conclusions: Senescent cells can contribute to the growth of tumors by providing cytokines not expressed by proliferating cells, but required by these to thrive.
- © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
No hay comentarios:
Publicar un comentario