Molecular cytogenetic characterization of human breast cancer cell line MDA-MB-468 and its variant 468LN, which displays aggressive lymphatic metastasis

Abstract

Two human breast carcinoma cell lines, MDA-MB-468 and its variant MDA-MB-468LN, which displays aggressive lymphatic metastasis, were investigated for molecular cytogenetic characteristics using G-banding, spectral karyotyping, and fluorescence in situ hybridization (FISH). Both cell lines have multiple chromosome aberrations, but differ in the types of rearrangements and their breakpoints. The MDA-MB-468 karyotype identified in the present study differs from that previously reported, which suggests that this cell line is unstable. Neither cell line exhibited amplification of ERBB2 (alias HER-2) by FISH. MDA-MB-468 cells have a modal number of 60, with 42 types of aberrations: 11 numerical and 31 structural. 468LN cells have a modal number of 55, with 37 types of aberrations: 10 numerical and 27 structural. The most common aberrations in MDA-MB-468 cells were der(5)t(5;16), i(7)(p10), i(18)(p10), der(19)t(2;19), del(6)(q23), and der(10)t(1;10). The most common aberrations in 468LN cells were der(18)t(10;18), +5, der(1;7)(q10;q10), der(19)t(2;18;19), and der(20)t(20;21). This cytogenetic result is consistent with previous findings that showed differences in tumorigenicity and metastatic capability of these two cell lines and indicates that 468LN is a new cell line distinctive from MDA-MB-468. We hypothesize that the cytogenetic changes in 468LN may be related to its new biological characteristics. Knowledge of the chromosome aberrations and breakpoints identified could be useful for further genetic and epigenetic studies of breast cancer.