Related Experiment Video
Updated: May 29, 2026

Visualization and Quantitative Analysis of Genotoxin-Induced PARP1/PARP2 Activation in Cells Using a Fluorescent Fusion Protein-Based Reporter
Published on: April 17, 2026
Nuclear PARP-1 protein overexpression is associated with poor overall survival in early breast cancer
F Rojo1, J García-Parra2, S Zazo3
1Cancer Research Program, IMIM (Hospital del Mar Research Institute), Barcelona; Department of Pathology, Hospital del Mar, Barcelona; Department of Pathology, IIS-Fundación Jiménez Díaz, Madrid.
Background:
Poly(ADP-ribose)polymerase-1 (PARP-1) is a highly promising novel target in breast cancer. However, the expression of PARP-1 protein in breast cancer and its associations with outcome are yet poorly characterized.
Patients And Methods:
Quantitative expression of PARP-1 protein was assayed by a specific immunohistochemical signal intensity scanning assay in a range of normal to malignant breast lesions, including a series of patients (N = 330) with operable breast cancer to correlate with clinicopathological factors and long-term outcome.
Results:
PARP-1 was overexpressed in about a third of ductal carcinoma in situ and infiltrating breast carcinomas. PARP-1 protein overexpression was associated to higher tumor grade (P = 0.01), estrogen-negative tumors (P < 0.001) and triple-negative phenotype (P < 0.001). The hazard ratio (HR) for death in patients with PARP-1 overexpressing tumors was 7.24 (95% CI; 3.56-14.75). In a multivariate analysis, PARP-1 overexpression was an independent prognostic factor for both disease-free (HR 10.05; 95% CI 5.42-10.66) and overall survival (HR 1.82; 95% CI 1.32-2.52).
Conclusions:
Nuclear PARP-1 is overexpressed during the malignant transformation of the breast, particularly in triple-negative tumors, and independently predicts poor prognosis in operable invasive breast cancer.
More Related Videos
Related Concept Videos
Abnormal Proliferation
The Nucleolus
Long-patch Base Excision Repair
DNA Damage Can Stall the Cell Cycle
DNA Damage can Stall the Cell Cycle
The Intrinsic Apoptotic Pathway

