Immunohistochemical expression of Hairy and Enhancer of Split 1 (HES1) protein in breast carcinoma

• Published in: Egyptian journal of pathology Vol. 43; no. 2; pp. 164 - 170
• Main Authors: Shibel, Passant E.E., Mohamed, Alyaa A.E., El Aziz, Ahmed M. Abd, Khairy, Rasha A.
• Format: Journal Article
• Language: English
• Published: 01.07.2023
• ISSN: 1687-4277; 2090-5378
• DOI: 10.4103/egjp.egjp_24_23

Background Hairy and Enhancer of Split 1 (HES1) is a transcription factor involved in cell differentiation, proliferation, and in various cancer progression. Recently, HES1 was addressed as a potential biomarker that induces stem cell features in breast cancer and stimulates epithelial-mesenchymal transition in triple-negative breast cancer (TNBC). Aim This study aimed to assess HES1 immunohistochemical (IHC) expression in invasive breast carcinoma and correlate it with the clinicopathological variables and different molecular subtypes of the cases. Patients and methods IHC was conducted on 76 paraffin blocks with an anti-HES1 monoclonal antibody, and a final IHC score was calculated based on staining intensity and percentage of positively stained cells. A final IHC of greater than or equal to 4 was considered an HES1 positive expression. Results HES1 expression was positive in 18 (23.7%) cases and was significantly associated with breast cancer HER2-enriched molecular subtype, followed by triple-negative breast cancer ( P <0.05). HES1 expression was also significantly associated with estrogen and progesterone receptor negativity and HER2 overexpression ( P <0.05). Positive HES1 expression was associated with high tumor grade, advanced stage, high Ki-67 proliferation index, and presence of tumor vascular emboli, although it did not reach statistical significance ( P >0.05). Conclusion Our study demonstrated that the HES1 protein showed a significantly higher expression in nonluminal breast cancer subtypes. In addition, it could have a potential role in the growth and spread of breast cancer cells. These findings suggest that HES1 is a possible promising target for therapeutic interventions.