title: Genetic instability of RBM5/LUCA-15/H37 in MCF-7 breast carcinoma sublines may affect susceptibility to apoptosis.
abstract: The MCF-7 human breast carcinoma cell line is widely used as a model system by breast cancer researchers and cell biologists investigating apoptosis. Since its establishment 30 years ago, from a patient with metastatic breast cancer, the original MCF-7 cell population has undergone genetic drift to such an extent that numerous genetically diverse sublines now exist. For instance, it has been reported that MCF-7 cells have lost the region 3p21.3, to which the apoptosis regulatory protein and putative tumour suppressor LUCA-15 (also called RBM5 and H37) maps; however, LUCA-15 has been cloned from MCF-7 cells, and LUCA-15 expression analyses have been conducted using MCF-7 cells. To address this discrepancy, we characterized three MCF-7 sublines by Western blot, RT-PCR and finally genomic PCR analysis, and determined that one of the three had lost the LUCA-15 gene. Interestingly, loss of LUCA-15 was positively correlated with decreased susceptibility to the death-inducing ligand TNF-alpha. Subsequent overexpression of exogenous LUCA-15 was shown to enhance TNF-alpha-mediated apoptosis, suggesting that LUCA-15 may play a role in regulating the susceptibility of breast cancer cells to drug-induced apoptosis. These results not only reinforce the necessity of MCF-7 subline characterization, but provide the first evidence of an apoptotic modulatory role for LUCA-15 in a non-T cell line.
authors.affiliation: Northeastern Ontario Regional Cancer Centre, Tumour Biology Group, Sudbury, Ontario P3E 5J1, Canada.
authors.forename: Nina D
authors.initials: ND
authors.lastname: Rintala-Maki
authors.forename: Virginia
authors.initials: V
authors.lastname: Abrasonis
authors.forename: Maureen
authors.initials: M
authors.lastname: Burd
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Sutherland
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D003513:Cycloheximide / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004268:DNA-Binding Proteins; D005260:Female; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016147:Genes, Tumor Suppressor; D042822:Genomic Instability; D006801:Humans; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D016133:Polymerase Chain Reaction; D016601:RNA-Binding Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D025521:Tumor Suppressor Proteins / Q000032:analysis / Q000235:genetics* / Q000502:physiology
chemical_list: D018797:Cell Cycle Proteins; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; C473448:RBM5 protein, human; D016601:RNA-Binding Proteins; D014409:Tumor Necrosis Factor-alpha; D025521:Tumor Suppressor Proteins; D003513:Cycloheximide; D011065:Poly(ADP-ribose) Polymerases