Comparison of functional proteomic analyses of human breast cancer cell lines T47D and MCF7

Abstract

T47D and MCF7 are two human hormone-dependent breast cancer cell lines which are widely used as experimental models for in vitro and in vivo (tumor xenografts) breast cancer studies. Several proteins involved in cancer development were identified in these cell lines by proteomic analyses. Although these studies reported the proteomic profiles of each cell line, until now, their differential protein expression profiles have not been established. Here, we used two-dimensional gel and mass spectrometry analyses to compare the proteomic profiles of the two cell lines, T47D and MCF7. Our data revealed that more than 164 proteins are differentially expressed between them. According to their biological functions, the results showed that proteins involved in cell growth stimulation, anti-apoptosis mechanisms and cancerogenesis are more strongly expressed in T47D than in MCF7. These proteins include G1/S-specific cyclin-D3 and prohibitin. Proteins implicated in transcription repression and apoptosis regulation, including transcriptional repressor NF-X1, nitrilase homolog 2 and interleukin-10, are, on the contrary, more strongly expressed in MCF7 as compared to T47D. Five proteins that were previously described as breast cancer biomarkers, namely cathepsin D, cathepsin B, protein S100-A14, heat shock protein beta-1 (HSP27) and proliferating cell nuclear antigen (PCNA), are found to be differentially expressed in the two cell lines. A list of differentially expressed proteins between T47D and MCF7 was generated, providing useful information for further studies of breast cancer mechanisms with these cell lines as models.

Figure 1. Proteomic analysis of T47D and MCF7 cells using 2-D gels and mass spectrometry.

(A) Representative 2-D gel images for T47D and MCF7 cells showing some differentially expressed spots. The 2-D gels were scanned and the differentially expressed (2-fold or higher, p<0.05) proteins were detected using Progenesis software. Arrows indicate some identified protein spots picked for MS analysis. The numbers refer to the spot number listed in Table 1 and 2. Spot numbers 2685, 2879 and 4364 were unique in either cell line whereas spot numbers 2903 and 4375 were up-regulated in one cell line compared to the other cell line. 1 and 2 represent two different regions of the entire 2-D gel images. (B) Summary of the numbers of spots and proteins obtained from the 2-D gel and mass spectrometry analyses of T47D and MCF7. * Up-regulated (up) and down-regulated (down) proteins in T47D cell line as compared to MCF7 cell line.

Figure 2. Functions and cellular locations of the differentially expressed proteins in T47D and MCF7 cells identified by the proteomics approach.

The Uniprot database was used to generate the cellular location and the molecular function and/or biological process of each of the 164 non-redundant (distinct) proteins identified by mass spectrometry analysis as differentially regulated in T47D as compared to MCF7 cells.