Effective treatment of triple-negative breast cancer with targeted cytotoxic somatostatin analogue AN-162 (AEZS-124)

619 Background: Triple negative breast cancers (TNBC) represent a distinct subtype of breast cancer being negative to ER, PR and HER2 and are associated with poor prognosis. Limited systemic treatment options exist for TNBC. TNBC cells express somatostatin receptors (SSTR). Therefore, to investigate preclinical characteristics of TNBC we used a novel targeted cytotoxic somatostatin analogue AN-162 containing doxorubicin (DOX) which binds to the subtypes 2, 3 and 5 of SSTR. Methods: The expression of SSTR in HCC 1806 human TNBC cell line was detected by RT-PCR. Cytotoxic effect of AN-162 in vitro was visualized by ethidium bromide staining fluorescence microscopy. Internalization of AN-162 into HCC 1806 cells was tested by 125Iodide-labeled AN-162 uptake assays and the presence of DOX in the nucleus was measured by fluorescence assays after separating the nucleus from the cytoplasm. For in vivo experiments, HCC 1806 TNBC cells were xenografted subcutaneously into nude mice which were then randomized into f...