title: Generation of MCF-7 cells with aggressive metastatic potential in vitro and in vivo.
abstract: Epithelial-mesenchymal transition (EMT) is a cellular development program characterized by loss of cell adhesion and increased cell mobility. It is essential for numerous processes including metastasis. In this study we have generated "aggressive" MCF-7 breast cancer cells (MCF-7-EMT), which show significantly increased invasion in contrast to wild type MCF-7 (MCF-7 WT) cells. In addition, we have analyzed, whether these cell lines differ in their metastatic behavior in vivo and in expression of invasion and/or EMT-relevant genes. Invasive behavior of different human breast cancer cell lines was tested. "Aggressive" MCF-7 cells (MCF-7-EMT) were generated using coculture and mammosphere culture techniques. To analyze whether or not MCF-7-EMT cells in contrast to MCF-7 WT cells form metastases in vivo, we assessed metastases in a nude mouse model. mRNA expression profiles of MCF-7 WT cells and MCF-7-EMT cells were compared using the Affymetrix micro array technique. Expression of selected genes was validated using real-time PCR. In addition, protein expression of epithelial marker E-cadherin (CDH1) and mesenchymal markers N-cadherin (CDH2), Vimentin (VIM), and TWIST was compared. The breast cancer cell lines showed different invasive behavior from hardly any invasion to a stronger cell movement. Coculture with osteoblast-like MG63 cells led to significantly increased cell invasion rates. The highest increase was shown using MCF-7 WT cells. Generated MCF-7-EMT cells showed significantly increased invasion as compared to MCF-7 WT cells. In 8 of 10 mice bearing orthotopically growing MCF-7-EMT tumors, we could detect metastases in liver and lung. In mice bearing MCF-7 WT tumors (n = 10), no metastases were found. MCF-7 WT cells and MCF-7-EMT cells were different in expression of 325 genes. Forty-four of the most regulated 50 invasion and/or EMT-related genes were upregulated and 6 genes were downregulated in MCF-7-EMT cells. Protein expression of mesenchymal markers CDH2, VIM, and TWIST was clearly increased in MCF-7-EMT cells. Protein expression of epithelial marker CDH1 was clearly decreased. With the breast cancer cell lines, MCF-7-EMT and MCF-7 WT cells, we have an excellent model of cells for further studies of EMT and invasion in vitro and in vivo.
authors.affiliation: Department of Gynecology and Obstetrics, Georg-August-University, Robert-Koch-Street 40, 37075, Göttingen, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Ziegler
authors.forename: Marie-Therese
authors.initials: MT
authors.lastname: Hansen
authors.forename: Maike
authors.initials: M
authors.lastname: Haase
authors.forename: Günter
authors.initials: G
authors.lastname: Emons
authors.forename: Carsten
authors.initials: C
authors.lastname: Gründker
mesh_terms: D000818:Animals; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D018920:Coculture Techniques; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D066298:In Vitro Techniques; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary*; D008175:Lung Neoplasms / Q000378:metabolism / Q000556:secondary*; D061986:MCF-7 Cells; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D012333:RNA, Messenger