Therapeutic Advantage of Targeting PRMT5 in Combination with Chemotherapies or EGFR/HER2 Inhibitors in Triple-Negative Breast Cancers

Computational insights into overcoming resistance mechanisms in targeted therapies for advanced breast cancer: focus on EGFR and HER2 co-inhibition

In the present study, the formation of a heterodimer involving both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) has been explored as a potential therapeutic mechanism to inhibit the progression of breast cancer. Virtual screening using molecular docking resulted in the three hit compounds (ZINC08382411, ZINC08382438, and ZINC08382292) with minimum binding scores and commonly binding to both receptors. Further, MD simulation analysis of these complexes illustrated the high stability of these compounds with EGFR and HER2. RMSD showed that ZINC08382411 displayed the most stable RMSD of 2 - 3 Å when bound to both receptors, suggesting to have strong compatibility with the active site of the receptor. Hydrogen bond analysis showed that ZINC08382411 forms the maximum number of H-bonds (2 to 3) in both EGFR and HER2 bound complexes, with the highest occupancy of 62% and 79%, respectively. Binding free energy calculation showed that ZINC08382411 possesses maximum affinity towards both the receptors with ΔGbind = -129.628 and -164.063 kJ/mol, respectively. This approach recognizes the significance of EGFR and HER2 in breast cancer development and aims to disrupt their collaborative signaling, which is known to promote the antagonistic behavior of cancer cells. By focusing on this EGFR/HER2 heterodimer, the study offers a promising avenue for identifying a potential candidate (ZINC08382411) that may inhibit breast cancer cell growth and potentially improve patient outcomes. The study's findings may contribute to the ongoing efforts to advance breast cancer treatment strategies.

Antibody-drug conjugates in breast cancer treatment: resistance mechanisms and the role of therapeutic sequencing

Antibody-drug conjugates (ADCs) are a transformative approach in breast cancer therapy, offering targeted treatment with reduced toxicity by selectively delivering cytotoxic agents to cancer cells. While ADCs like trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd), and sacituzumab govitecan have shown significant efficacy, resistance mechanisms such as antigen loss, impaired internalization, and efflux of cytotoxic payloads challenge their effectiveness. This review discusses these resistance mechanisms and explores advanced strategies to overcome them, including innovations in linker chemistry, multi-antigen targeting, and biomarker-driven personalization. Additionally, therapeutic sequencing - determining the optimal order of ADCs with other treatments such as chemotherapy, endocrine therapy, and immunotherapy - is examined as a crucial approach to maximize ADC efficacy and manage resistance. Evidence-based sequencing strategies, particularly for human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer (TNBC), are supported by clinical trials demonstrating the benefits of ADCs in both early-stage and metastatic settings. The potential of combination therapies, such as ADCs with immune checkpoint inhibitors (ICIs), further highlights the evolving landscape of breast cancer treatment. As ADC technology advances, personalized approaches integrating biomarkers and optimized sequencing protocols offer promising avenues to enhance treatment outcomes and combat resistance in breast cancer.