ABSTRACT
Background: Breast cancer is a heterogeneous disease characterized by differential responses to targeted and chemotherapeutic agents. Antibody-drug conjugates are one of the promising strategies for the treatment of breast cancer. Monomethyl auristatin E [MMAE] is a highly potent microtubule inhibitor and a common payload used for development of antibody-drug conjugates. The purpose of this study was to investigate the cytotoxic effects of MMAE on breast cancer cell lines
Materials and Methods: MDA-MB-468 and MDA-MB-453 cells were treated with MMAE at various concentrations [1, 10, 100, and 1000 ng/ml], and cytotoxicity was measured after 48 and 72 hours using an MTT assay
Results: Our findings indicated that MMAE possesses dose- and time-dependent cytotoxic activities against human breast cancer cells. The morphological features of the treated cells were supportive of the cytotoxic activity of MMAE. The results of the MTT assay showed that MMAE has a significant cytotoxicity against MDA-MB-468 and, to a lesser degree, MDA-MB-453 cells
Conclusion: MMAE can be used as a highly cytotoxic payload for development of antibody-drug conjugates against breast cancer
ABSTRACT
Background: Reduction/alkylation is one of the leading strategies for the development of antibody drug conjugates [ADCs]. Precise control of the reduction process would not only yield a defined number of free thiols per antibody but also result in development of more homogenous conjugates
Methods: In the present study, we investigated the effect of various dithiothreitol [DTT] concentrations, temperature conditions, and DTT exposure times on antibody reduction. After antibody reduction, the Ellman's test and SDS-PAGE analysis were used to evaluate free thiols produced and confirm the reduction process, respectively
Results: DTT concentration seems to be a potential factor in the reduction process. Concentrations of 0.1, 1, 5, 10, 20, 50, and 100 mM DTT at 37[degree]C for 30 minutes resulted in approximately 0.4, 1.2, 5.4, 7, 8, 8, and 8 thiols per antibody, respectively
Conclusion: Optimized site specific conjugation can provide better process control and reproducibility for the development of disulfide-based ADCs