Research Journal of Oncology Open Access

The Role of HER2 in Cancer: A Potent Oncogene and Therapeutic Target

William Chen^* Department of Cancer Genomics, University of Beijing, China
^*Correspondence: William Chen, Department of Cancer Genomics, University of Beijing, China, Email:

Received: 02-Sep-2024, Manuscript No. IPRJO-24-22016; Editor assigned: 04-Sep-2024, Pre QC No. IPRJO-24-22016 (PQ); Reviewed: 18-Sep-2024, QC No. IPRJO-24-22016; Revised: 23-Sep-2024, Manuscript No. IPRJO-24-22016 (R); Published: 30-Sep-2024, DOI: 10.36648/iprjo-8.3.29

Introduction

Oncogenes are mutated or overexpressed genes that contribute to cancer development by promoting cell division and survival. Among these, the Human Epidermal Growthfactor Receptor 2 (HER2) gene stands out as a well-studied oncogene with significant implications in cancer, particularly in breast cancer. The discovery of HER2 and the development of targeted therapies against it have dramatically changed the treatment landscape for HER2-positive cancers, offering new hope to patients with previously poor prognoses. The HER2 gene is part of the EGFR (Epidermal Growth Factor Receptor) family, also known as the ErbB family, which consists of four structurally related receptors (HER1, HER2, HER3, and HER4).

Description

These receptors play crucial roles in cell growth, differentiation, and survival by triggering a cascade of intracellular signaling pathways. HER2 encodes a receptor tyrosine kinase protein that resides on the surface of cells. Unlike other EGFR family members, HER2 does not have a known ligand, meaning it does not need to bind an external growth factor to become active. Instead, it activates by forming dimers, or paired units, with other HER family receptors, setting off signals that lead to cell proliferation. In normal cells, HER2 expression is tightly regulated, and only a small amount of the HER2 protein is present on the cell surface. However, in some cancerous cells, the HER2 gene is amplified, resulting in an abnormally high number of HER2 proteins on the cell membrane. This overexpression leads to excessive signaling for cell growth and division, contributing to the uncontrolled proliferation characteristic of cancer. HER2 is particularly relevant in breast cancer, where its amplification occurs in about 15-20% of cases. HER2-positive breast cancers tend to be more aggressive than HER2-negative cancers and are associated with a higher likelihood of recurrence and metastasis. The presence of HER2 overexpression has become an essential factor in classifying breast cancer, as it not only informs the prognosis but also determines treatment options. Beyond breast cancer, HER2 amplification has been observed in other cancer types, such as gastric, ovarian, and lung cancers. These findings highlight the gene’s broader role in oncogenesis and have led to studies exploring HER2-targeted therapies for various HER2-overexpressing cancers. The primary mechanism through which HER2 drives cancer development is through continuous activation of downstream signaling pathways, especially the MAPK and PI3K/Akt pathways. These pathways are crucial for cell cycle progression, survival, and metabolic adaptation in cancer cells. When HER2 is overexpressed, these pathways remain persistently active, allowing cancer cells to evade normal regulatory mechanisms like apoptosis (programmed cell death), which would otherwise control aberrant cell growth. HER2 also promotes oncogenesis by enhancing the tumor’s ability to recruit blood vessels, a process called angiogenesis, which provides oxygen and nutrients to the rapidly growing cancer cells. Moreover, HER2 signaling contributes to the ability of cancer cells to invade surrounding tissues and metastasize, leading to the spread of cancer to distant organs.

Conclusion

HER2 is a powerful oncogene that plays a pivotal role in the development and progression of several cancers, most notably breast cancer. The discovery of HER2’s function in cancer and the subsequent development of targeted therapies represent one of the most successful examples of precision oncology. While challenges such as drug resistance persist, ongoing research continues to enhance our understanding of HER2- driven cancers and refine therapies, offering the promise of better outcomes for patients with HER2-positive cancers.