Characteristics of stem sings of EPCAM-negative and EPCAM-positive tumor cells in primary tumor and 2D and 3D cultures in breast cancer

One of the predictors of adverse prognosis in breast cancer is the overexpression of the EpCAM protein. However, a significant part of tumor cells have low or no EpCAM expression. The molecular features and the ability to grow in 2D and 3D cultures, indirectly reflecting metastatic potential of tumor cells without EpCAM expression, have not been sufficiently studied. The aim of the study was to compare phenotypic variants of stem cells and EMT depending on the EpCAM expression in the primary tumor of breast cancer and 2D and 3D cultures. Material and Methods. The study included 7 patients with invasive breast carcinoma of no special type. Luminal A subtype was found in 2/7 patients (29 %), and luminal B HER2-negative molecular subtype was found in 5/7 patients (71 %). The patients didn’t have neoadjuvant chemotherapy. Cells from the primary tumor were cultured in 2D and 3D. The primary tumor cells, 2D and 3D cultures were phenotyped using flow cytometry with antibodies targeting: CD45, EpCAM (CD326), CD44, CD24, N-cadherin (CD325), and CD133, CK7/8, EpCAM (CD326).