TY - JOUR
T1 - Gene expression profiling of the tumor microenvironment during breast cancer progression
AU - Ma, Xiao Jun
AU - Dahiya, Sonika
AU - Richardson, Elizabeth
AU - Erlander, Mark
AU - Sgroi, Dennis C.
N1 - Funding Information:
The present study was supported by NIH RO1-1CA112021-01 (to DCS), the Department of Defense grants W81XWH-04-1-0606 and DAMD170310428 (to DCS), Susan G. Komen Breast Cancer Foundation grant BCTR0402932 (to DCS), and the Avon Foundation (to DCS). The authors thank Erica Chatfield for technical assistance in microdissection and RNA extraction, and they thank Sridhar Ramaswamy and E. Schmidt for helpful discussions and reading of the manuscript.
PY - 2009/2/2
Y1 - 2009/2/2
N2 - Introduction: The importance of the tumor microenvironment in breast cancer has been increasingly recognized. Critical molecular changes in the tumor stroma accompanying cancer progression, however, remain largely unknown. We conducted a comparative analysis of global gene expression changes in the stromal and epithelial compartments during breast cancer progression from normal to preinvasive to invasive ductal carcinoma.Methods: We combined laser capture microdissection and gene expression microarrays to analyze 14 patient-matched normal epithelium, normal stroma, tumor epithelium and tumor-associated stroma specimens. Differential gene expression and gene ontology analyses were performed.Results: Tumor-associated stroma undergoes extensive gene expression changes during cancer progression, to a similar extent as that seen in the malignant epithelium. Highly upregulated genes in the tumor-associated stroma include constituents of the extracellular matrix and matrix metalloproteases, and cell-cycle-related genes. Decreased expression of cytoplasmic ribosomal proteins and increased expression of mitochondrial ribosomal proteins were observed in both the tumor epithelium and the stroma. The transition from preinvasive to invasive growth was accompanied by increased expression of several matrix metalloproteases (MMP2, MMP11 and MMP14). Furthermore, as observed in malignant epithelium, a gene expression signature of histological tumor grade also exists in the stroma, with high-grade tumors associated with increased expression of genes involved in immune response.Conclusions: Our results suggest that the tumor microenvironment participates in tumorigenesis even before tumor cells invade into stroma, and that it may play important roles in the transition from preinvasive to invasive growth. The immune cells in the tumor stroma may be exploited by the malignant epithelial cells in high-grade tumors for aggressive invasive growth.
AB - Introduction: The importance of the tumor microenvironment in breast cancer has been increasingly recognized. Critical molecular changes in the tumor stroma accompanying cancer progression, however, remain largely unknown. We conducted a comparative analysis of global gene expression changes in the stromal and epithelial compartments during breast cancer progression from normal to preinvasive to invasive ductal carcinoma.Methods: We combined laser capture microdissection and gene expression microarrays to analyze 14 patient-matched normal epithelium, normal stroma, tumor epithelium and tumor-associated stroma specimens. Differential gene expression and gene ontology analyses were performed.Results: Tumor-associated stroma undergoes extensive gene expression changes during cancer progression, to a similar extent as that seen in the malignant epithelium. Highly upregulated genes in the tumor-associated stroma include constituents of the extracellular matrix and matrix metalloproteases, and cell-cycle-related genes. Decreased expression of cytoplasmic ribosomal proteins and increased expression of mitochondrial ribosomal proteins were observed in both the tumor epithelium and the stroma. The transition from preinvasive to invasive growth was accompanied by increased expression of several matrix metalloproteases (MMP2, MMP11 and MMP14). Furthermore, as observed in malignant epithelium, a gene expression signature of histological tumor grade also exists in the stroma, with high-grade tumors associated with increased expression of genes involved in immune response.Conclusions: Our results suggest that the tumor microenvironment participates in tumorigenesis even before tumor cells invade into stroma, and that it may play important roles in the transition from preinvasive to invasive growth. The immune cells in the tumor stroma may be exploited by the malignant epithelial cells in high-grade tumors for aggressive invasive growth.
UR - http://www.scopus.com/inward/record.url?scp=67549125238&partnerID=8YFLogxK
U2 - 10.1186/bcr2222
DO - 10.1186/bcr2222
M3 - Article
C2 - 19187537
AN - SCOPUS:67549125238
SN - 1465-5411
VL - 11
JO - Breast Cancer Research
JF - Breast Cancer Research
IS - 1
M1 - R7
ER -