Breast cancer is the most common and frequent cause of death in women in all types of cancer. Current treatment protocols do not provide a complete cure and targeting therapy can provide an important avenue for successful treatment of breast cancer. In this study, we aim to determine the therapeutic effects of the drug-conjugated carrier system with the conjugation of peptide sequence and antibody on HER2-positive breast cancer cells.
The selectivity of single nanocarriers were compared with doxorubicin (DOX) loaded-HER2 targeting peptide (LTVSPWY) and DOX loaded-monoclonal antibody (Herceptin®) on HER2-positive and HER2-negative breast cells. After defining the physicochemical characterization of micelle-based nanocarriers, the cytotoxic effects of micelles on healthy breast epithelial cells (MCF-10A, HER2-negative) and breast cancer cells (SKBR3- HER2-positive) were determined by MTT cell proliferation assay. Next, apoptotic and genotoxic effects of micelles (IC50 doses of DOX loaded-peptide conjugated) were determined by using JC-1 assay and Western Blotting (Bax and Bcl-2 proteins) and Commet assay, respectively. Also, drug-releasing was analyzed by flurosance microscopy with imaging processes. Lastly, cytostatic effects of micelles were investigated with cell cycle analysis.
DOX loaded-HER2 targeting peptide (DOX-Pep-HER-2-NCs) and DOX loaded-monoclonal antibody micelles (DOX-Anti-HER-2-NCs) had significant differences. DOX-Pep-HER-2-NCs had more toxic effects on SKBR-3 cells than DOX-Anti-HER-2-NCs. However, there is no significant change after the application of these micelles on MCF-10A cells. Besides, the intracellular amounts of doxorubicin with the application of DOX-Pep-HER-2-NCs were detected as higher in HER-2 positive breast cancer cells after measured by fluorescence imaging. Additionally, DOX-Pep-HER-2-NCs had more apoptotic, cytostatic and genotoxic effects on HER2 overexpressed SKBR-3 cells.
The targeting and therapeutic efficiency of DOX-Pep-HER-2-NCs were compared to DOX-Anti-HER-2-NCs on SKBR-3 cells. DOX-Pep-HER-2-NCs was more effective than DOX-Anti-HER-2-NCs on SKBR-3 cells in terms of targeting and therapeutic effects.
Prof. Dr. Sevil Dinçer İşoğlu & Prof. Dr. Alper İşoğlu.
This project was supported by The Scientific and Technological Research Council of Turkey (1003 Project-216S991).
All authors have declared no conflicts of interest.