Triple negative breast cancer cell sub-lines differences in MDA-MB-231 cell culture

Abstract

Introduction Triple negative breast cancer (TNBC) includes a heterogeneous subgroup of tumors accounting for approximately 15-20% of all breast cancers. TNBC presents a more aggressive natural history and worse disease-specific outcomes than other breast cancer subtypes [1]. Cellular heterogeneity is observed in TNBC and represents a major hurdle for effective therapy [2]. Scientists found that in genetically homogenous cell populations, the phenotypic heterogeneity is frequently observed in vitro cell cultures even in a controlled environment [3]. Identifying the differences between populations and their response to anticancer drugs could help to predict the tumor resistance to chemotherapy and help rationalize the choice of appropriate antineoplastic drugs, paying attention to the nature and relationship of the phenotypic populations of the tumor [4]. The aim of the study was to isolate phenotypically different cell sub-populations (sub-lines) from the commercial MDA-MB-231 cell line. Materials and Methods Sub-line isolation was performed by multiple dilutions of the cell suspension and passage to a 96 well microplate. Based on the morphological differences of separate colonies, those cell sublines that were most distinct in appearance and in the density of the colony were selected. Also, sublines have been characterized by the expression of the CD133 receptor (immunofluorescence staining), their susceptibility to anticancer drugs doxorubicin (DOX) and paclitaxel (PTX) (MTT assay), and by ability to migrate (wound healing assay). All the experiments were done in at least triplicate independent measurements. Student’s t-test was used, and p-values were calculated. A value of p<0.05 was considered as the level of significance. Results and discussion The expression of the CD133 receptor was more than 30% higher in the subline E7 compared to the commercial cell line MDA-MB-231. The susceptibility of cell subli[...].