Open Access

ARTICLE

CDKN1A/p21 Influences the Survival and Expansion of Breast Cancer Stem Cells after Oxidative Damage

Evangelos Manousakis¹, Cristina Moreta-Moraleda¹, Clàudia Martinez Miralles¹, Anna Tomàs Pujolà¹, Houda Baccara², Laia Liñán Franquet¹, Montserrat Montañés Albó¹, Roberto Ferrari², Roni H. G. Wright^1,*

1 Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya (UIC), Barcelona, Spain
2 Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy

* Corresponding Author: Roni H. G. Wright. Email:

(This article belongs to the Special Issue: Advances in Pathology, Early Diagnosis and Therapeutic Strategies for Breast Cancer)

Oncology Research 2026, 34(5), 20 https://doi.org/10.32604/or.2026.074965

Received 22 October 2025; Accepted 11 February 2026; Issue published 22 April 2026

Abstract

Objective: Breast cancer remains one of the most prevalent malignancies among women worldwide, and despite advances in therapy and treatment options, tumour relapse and metastasis remain major clinical challenges, largely driven by the breast cancer stem cells (BCSCs) niche that resists conventional treatments and regenerates tumours. In breast cancer, where approximately 30% of patients who initially respond to treatment ultimately relapse and die of metastatic disease, targeting BCSCs is critical for improving patient outcomes. Cyclin-dependent kinase inhibitor 1A/p21 (CDKN1A/p21) is a multifunctional protein that is known primarily for its role in regulating the cell cycle in response to DNA damage. However, in this study, we aimed to explore the role of CDKN1A/p21 in the survival and expansion of BCSCs. Methods: We used three-dimensional in vitro models to assess the influence of CDKN1A/p21 expression on the survival of BCSCs both under basal conditions and after oxidative damage. Spatial transcriptomics analysis and chromatin immunoprecipitation-quantitative PCR (qPCR) were used to investigate the role of CDKN1A/p21 in the regulation and control of BCSC gene expression signatures. Results: We demonstrated that alterations in CDKN1A/p21 expression affect the ability of breast cancer cells to grow and survive after oxidative damage. Mechanistically, we found that CDKN1A/p21 directly binds to the promoter and regulates the expression of CD44, SPP1, and TMSB10, a combination gene signature that is associated with a greater probability of recurrence and metastasis in breast cancer patients. Conclusions: We propose that changes in gene regulation mediated by CDKN1A/p21 possibly contribute to cancer stem cell survival after oxidative damage, thus making CDKN1A/p21 a promising target for future drug discovery projects aimed at addressing the issue of therapeutic resistance and breast cancer metastasis.

---

Graphic Abstract

---

Keywords

---

Supplementary Material

Supplementary Material File

---