Abstract |
Accumulating evidence suggests that multiple complex mechanisms may be involved, simultaneously or complementarily, in the emergence and development of multidrug resistance (MDR) in various cancers. Cell adhesion-mediated MDR is one such mechanism. In the present study, we initially observed increased cell adhesion to extracellular matrix proteins by the MDR human breast tumor cell line MCF-7/MX compared to its parental cells. We then used a strategy that combined antibody-based screening technique and mass spectrometry-based proteomics to identify membrane proteins that contribute to the enhanced adhesion of MCF-7/MX cells. Using MCF-7/MX cells as immunogen, we isolated a mouse monoclonal antibody, 9C6, that preferentially reacts with MCF-7/MX cells over the parental MCF-7 cells. The molecular target of 9C6 was identified as cytokeratin 8 (CK8), which was found to be overexpressed on the cell surface of MCF-7/MX cells. We further observed that down-regulation of cell surface levels of CK8 through siRNA transfection significantly inhibited MCF-7/MX cell adhesion to fibronectin and vitronectin. In addition, anti-CK8 siRNA partially reversed the MDR phenotype of MCF-7/MX cells. Taken together, our results suggest that alterations in the expression level and cellular localization of CK8 may play a significant role in enhancing the cellular adhesion of MDR MCF-7/MX cells.
|
Authors | Fang Liu, Zhong Chen, Jinhong Wang, Xiaofeng Shao, Ziyou Cui, Chunzheng Yang, Zhenping Zhu, Dongsheng Xiong |
Journal | Neoplasia (New York, N.Y.)
(Neoplasia)
Vol. 10
Issue 11
Pg. 1275-84
(Nov 2008)
ISSN: 1476-5586 [Electronic] United States |
PMID | 18953437
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Antibodies, Monoclonal
- Fibronectins
- Keratin-8
- RNA, Small Interfering
- Vitronectin
- Mitoxantrone
|
Topics |
- Animals
- Antibodies, Monoclonal
(immunology)
- Breast Neoplasms
(metabolism, pathology, physiopathology)
- Cell Adhesion
- Cell Line, Tumor
- Cell Membrane
(metabolism)
- Down-Regulation
- Drug Resistance, Multiple
- Drug Resistance, Neoplasm
- Extracellular Matrix
(pathology, physiology)
- Female
- Fibronectins
- Gene Expression Regulation, Neoplastic
- Humans
- Keratin-8
(immunology, metabolism)
- Mice
- Microscopy, Confocal
- Microscopy, Fluorescence
- Mitoxantrone
- Polymerase Chain Reaction
- Proteomics
- RNA, Small Interfering
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Statistics, Nonparametric
- Tandem Mass Spectrometry
- Vitronectin
|