Research article

Two-dimensional electrophoretic comparison of metastatic and non-metastatic human breast tumors using in vitro cultured epithelial cells derived from the cancer tissues

Jan Vydra^{* 1} , Irena Selicharová^{* 2} , Kateřina Smutná^{* 2} , Miloslav Šanda^{* 2} , Eva Matoušková^{* 3,4,5} , Eva Buršíková^{* 3,4,5} , Markéta Prchalová^{* 4,5} , Zuzana Velenská^{* 6} , David Coufal^{* 7} and Jiří Jiráček^{* 2}

¹Department of Oncology, 1st Faculty of Medicine, Charles University Prague, Czech Republic

²Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic

³Institute of Biochemistry and Experimental Oncology, 1st Faculty of Medicine, Charles University Prague, Czech Republic

⁴Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic

⁵Prague Burn Centre, 3rd Faculty of Medicine, Charles University Prague, Czech Republic

⁶Institute of Pathology 1st Faculty of Medicine, Charles University Prague and General Teaching Hospital, Prague, Czech Republic

⁷Institute of Computer Science, Academy of Sciences of the Czech Republic, Prague, Czech Republic

author email corresponding author email* Contributed equally

BMC Cancer 2008, 8:107doi:10.1186/1471-2407-8-107

Published:	16 April 2008

Abstract

Background

Breast carcinomas represent a heterogeneous group of tumors diverse in behavior, outcome, and response to therapy. Identification of proteins resembling the tumor biology can improve the diagnosis, prediction, treatment selection, and targeting of therapy. Since the beginning of the post-genomic era, the focus of molecular biology gradually moved from genomes to proteins and proteomes and to their functionality. Proteomics can potentially capture dynamic changes in protein expression integrating both genetic and epigenetic influences.

Methods

We prepared primary cultures of epithelial cells from 23 breast cancer tissue samples and performed comparative proteomic analysis. Seven patients developed distant metastases within three-year follow-up. These samples were included into a metastase-positive group, the others formed a metastase-negative group. Two-dimensional electrophoretical (2-DE) gels in pH range 4–7 were prepared. Spot densities in 2-DE protein maps were subjected to statistical analyses (R/maanova package) and data-mining analysis (GUHA). For identification of proteins in selected spots, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed.

Results

Three protein spots were significantly altered between the metastatic and non-metastatic groups. The correlations were proven at the 0.05 significance level. Nucleophosmin was increased in the group with metastases. The levels of 2,3-trans-enoyl-CoA isomerase and glutathione peroxidase 1 were decreased.

Conclusion

We have performed an extensive proteomic study of mammary epithelial cells from breast cancer patients. We have found differentially expressed proteins between the samples from metastase-positive and metastase-negative patient groups.