KCTD15 Is Overexpressed in her2+ Positive Breast Cancer Patients and Its Silencing Attenuates Proliferation in SKBR3 CELL LINE

Studies carried out in the last decade have demonstrated that the members of the KCTD protein family play active roles in carcinogenesis. Very recently, it has been reported that KCTD15, a protein typically associated with other physio-pathological processes, is involved in medulloblastoma and leukemia. Starting with some preliminary indications that emerged from the analysis of online databases that suggested a possible overexpression of KCTD15 in breast cancer, in this study, we evaluated the expression levels of the protein in breast cancer cell lines and in patients and the effects of its silencing in the HER2+ cell model. The analysis of the KCTD15 levels indicates a significant overexpression of the protein in Luminal A and Luminal B breast cancer patients as well as in the related cell lines. The greatest level of over-expression of the protein was found in HER2+ patients and in the related SKBR3 cell line model system. The effects of KCTD15 silencing in terms of cell proliferation, cell cycle, and sensitivity to doxorubicin were evaluated in the SKBR3 cell line. Notably, the KCTD15 silencing in SKBR3 cells by CRISPR/CAS9 technology significantly attenuates their proliferation and cell cycle progression. Finally, we demonstrated that KCT15 silencing also sensitized SKBR3 cells to the cytotoxic agent doxorubicin, suggesting a possible role of the protein in anti HER2+ therapeutic strategies. Our results highlight a new possible player in HER2 breast cancer carcinogenesis, paving the way for its use in breast cancer diagnosis and therapy.