Treatment of triple-negative breast cancer with anti CD133 antibody-modified shikonin-loaded microemulsion / 中草药

ABSTRACT

Objective To evaluate the feasibility and advantages of therapy of triple-negative breast cancer with Anti CD133 antibody-modified shikonin-loaded microemulsion (Anti CD133Ab-SKN-MEs). Methods Anti CD133Ab-SKN-MEs were prepared by a classic EDC/NHS conjugation technique. The drug loading efficiency and density of modified antibody were optimized using average particle size, Zeta potential and entrapment efficiency as indicators. The cell proliferation of MDA-MB-231 cells was investigated by MTT method. The cellular uptake of various formulations was qualitatively and quantitatively investigated using FITC as a probe. MDA-MB-231 cellular apoptosis induced by various treatments was evaluated by the Annexin V-PE/7-amino actinomycin D (Annexin V-PE/7-AAD) assay kit. MDA-MB-231 breast cancer stem cells (MDA-MB-231 CSC) was enriched by a suspension culture technique, and the cell morphology and proportion of CD133-positive cells were studied after treatment with various SKN formulations. The model of MDA-MB-231 tumor-bearing nude mice was established, and then injected five times every other day with saline, shikonin (SKN), SKN-MEs, and Anti CD133Ab-SKN-MEs at a dose of 4 mg/kg, to observe the tumor volume, survival time, tumor inhibition and CD133+ cells ratio during/after the treatment. Results The optimal mass ratio of SKN to total carrier was 1.0% in the preparation of Anti CD133Ab-SKN-MEs, and the optimal density of modified antibody was 0.025%.The particle was spherical with a particle size of (31.4 ± 2.1) nm, a potential of (-18.7 ± 2.5) mV and an encapsulation efficiency of (93.6 ± 2.8) %. The IC50 of Anti CD133Ab-SKN-MEs against MDA-MB-231 cells was (1.53 ± 0.43) μg/mL, the cell uptake of Anti CD133Ab-SKN-MEs was significantly higher than that of SKN-MEs and SKN, and 8 h incubation induced (67.9 ± 4.2)% cell apoptosis. Anti CD133Ab-SKN-MEs can significantly inhibit the globularity of MDA-MB-231 CSC, with a decrease in the number of CD133-positive cells. The in vivo tumor inhibition rate of Anti CD133Ab-SKN-MEs-treated mice was 78.5%, and 12.5% of tumor-bearing nude mice still survived at day 69. Moreover, the ratio of CD133-positive tumor cells within the tumor tissues was significantly reduced. Conclusion Anti CD133Ab-SKN-MEs has obvious advantages in treatment of triple-negative breast cancer, which might be related to the inhibition of tumor cells differentiation.