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Updated: Oct 10, 2026
Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
Published on: October 27, 2020
Proteomic detection of changes in protein synthesis induced by fibroblast growth factor-2 in MCF-7 human breast
A S Vercoutter-Edouart1, X Czeszak, M Crépin
1Equipe Facteurs de Croissance, UMR 8576 CNRS, Villeneuve d'Ascq, France.
Abstract:
Fibroblast growth factor-2 (FGF-2) is a potent regulator of breast cancer cell growth through stimulation of tyrosine kinase receptors and activation of the mitogen-activated protein kinase cascade. In the present study, we have investigated changes in protein synthesis induced by FGF-2 stimulation of the prototypic human breast cancer cell line MCF-7. Using high-resolution two-dimensional electrophoresis of (35)S amino acid metabolically labeled proteins and computerized analysis of 2D autoradiograms, we found that four proteins were up-regulated within the first 12 h of FGF-2 stimulation. Mass spectrometry analysis (MALDI-TOF and MS-MS) of tryptic fragments and database searches allowed the identification of these FGF-2-regulated proteins as the heat shock proteins HSP90 and HSP70, the proliferating cell nuclear antigen (PCNA), and the transcriptionaly controlled tumor protein (TCTP). We then analyzed the distribution of these proteins in various cancerous and normal breast epithelial cells. Interestingly, the four FGF-2-regulated proteins were found to be constitutively up-regulated in ras-transfected MCF-7 cells, indicating their relevance to the up-regulation of cellular proliferation. Moreover, HSP90 and PCNA were found at higher levels in cancerous cells than in normal cells. The role of HSP90 was further investigated using the specific inhibitor geldanamycin. We showed that the functionality of HSP90 is strictly required in order to obtain FGF-2 mitogenic stimulation in MCF-7 cells, indicating the crucial role played by this molecular chaperone in the control of breast cancer cell growth. Finally, these results show that proteomic analysis is a valuable method for identifying potential markers or therapeutic targets related to cancer growth.
Insights
Fibroblast growth factor-2 (FGF-2) stimulates breast cancer cell growth by up-regulating heat shock proteins (HSP90, HSP70), PCNA, and TCTP. HSP90 is crucial for FGF-2
Area of Science:
- Molecular Biology
- Proteomics
- Cancer Research
Background:
- Fibroblast growth factor-2 (FGF-2) significantly influences breast cancer cell proliferation via tyrosine kinase receptors and MAPK signaling.
- Understanding FGF-2's impact on protein synthesis is key to identifying breast cancer growth regulators.
Purpose of the Study:
- To investigate protein synthesis changes induced by FGF-2 in MCF-7 breast cancer cells.
- To identify specific proteins regulated by FGF-2 and analyze their role in cancer progression.
- To evaluate proteomic analysis as a method for discovering cancer biomarkers and therapeutic targets.
Main Methods:
- High-resolution two-dimensional electrophoresis of (35)S-labeled proteins.
- Computerized analysis of 2D autoradiograms.
- Mass spectrometry (MALDI-TOF, MS-MS) for protein identification.
- Analysis of protein distribution in cancerous and normal breast cells.
- Inhibition of HSP90 using geldanamycin.
Main Results:
- FGF-2 stimulation up-regulated four proteins: HSP90, HSP70, PCNA, and TCTP within 12 hours.
- These four proteins were constitutively up-regulated in ras-transfected MCF-7 cells, correlating with increased proliferation.
- HSP90 and PCNA levels were higher in cancerous cells compared to normal cells.
- HSP90 functionality was essential for FGF-2-induced mitogenic stimulation in MCF-7 cells.
Conclusions:
- Proteomic analysis effectively identifies proteins involved in cancer growth.
- HSP90, HSP70, PCNA, and TCTP are key FGF-2-regulated proteins in breast cancer.
- HSP90 plays a critical role in mediating FGF-2's mitogenic effects on breast cancer cells, suggesting it as a potential therapeutic target.
