endothelin-1 and Carcinoma-in-Situ

The objective of this study was to investigate expression of various growth factors associated with angiogenesis and lymphangiogenesis and of their receptors in ductal carcinomas in situ of the breast (DCIS). We studied protein expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF)-A, endothelin (ET)-1, and VEGF-C, and their receptors bFGF-R1, Flt-1, KDR, ET(A)R, ET(B)R, and Flt-4 immunohistochemically in 200 DCIS (pure DCIS: n=96; DCIS adjacent to an invasive component: n=104) using self-constructed tissue microarrays. Basic fibroblast growth factor-R1, VEGF-C, Flt-4, and ET(A)R were expressed in the tumour cells in the majority of cases, whereas bFGF and Flt-1 expression was rarely observed. VEGF-A, KDR, ET-1, and ET(B)R were variably expressed. The findings of VEGF-C and its receptor Flt-4 as lymphangiogenic factors being expressed in tumour cells of nearly all DCIS lesions and the observed expression of various angiogenic growth factors in most DCIS suggest that in situ carcinomas are capable of inducing angiogenesis and lymphangiogenesis. Moreover, we found a higher angiogenic activity in pure DCIS as compared to DCIS with concomitant invasive carcinoma. This association of angiogenic factors with pure DCIS was considerably more pronounced in the subgroup of non-high-grade DCIS (n=103) as compared with high-grade DCIS (n=94). Determination of these angiogenic markers may therefore facilitate discrimination between biologically different subgroups of DCIS and could help to identify a particularly angiogenic subset with a potentially higher probability of recurrence or of progression to invasiveness. For these DCIS, targeting angiogenesis may represent a feasible therapeutic approach for prevention of progression of DCIS to invasion.

Topics: Adolescent; Adult; Aged; Biomarkers; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Endothelin-1; Female; Fibroblast Growth Factor 2; Humans; Middle Aged; Protein Array Analysis; Receptor Protein-Tyrosine Kinases; Receptor, Fibroblast Growth Factor, Type 1; Receptors, Fibroblast Growth Factor; Receptors, Vascular Endothelial Growth Factor; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor C; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factor Receptor-2

Endothelin-1 (ET-1) is overexpressed in breast carcinomas and influences via its receptors (ETAR and ETBR) transformation, differentiation and growth processes in the human breast, but little is known about the ET expression in breast cancer precursors. On this basis we evaluated the expression of ET-1, ETAR and ETBR in a series of breast carcinomas, ductal (DCIS) and lobular carcinoma in situ (LCIS) and normal breast tissue by immunohistochemical (IH) methods. IH staining of ET-1, ETAR and ETBR was performed in 88 invasive breast carcinomas, with adjacent carcinoma in situ and concomitant normal breast tissue. Moderate or strong cytoplasmic immunostaining was observed for ET-1 in 33.3%, for ETAR in 45.3% and for ETBR in 55.7% of invasive breast carcinomas. Comparative analysis of invasive cancer (CA), concomitant carcinoma in situ (CIS) and normal breast epithelium (NBE) revealed a stepwise increase of ET-1 and ETAR expression in the sequence NBE < CIS < CA. ETBR expression tended to be slightly higher in CIS than in CA (NBE versus CIS and NBE versus CA, for ETAR and ETBR, p<0.001, respectively; NBE versus CA for ET-1, p=0.035). Our data suggest that the expression of ET-1, ETAR and ETBR correlates with the acquisition of malignant potential and may be used as a prognostic indicator of aggressive behaviour and invasive potential of premalignant breast lesions.

Topics: Biomarkers, Tumor; Breast Neoplasms; Carcinoma; Carcinoma in Situ; Carcinoma, Intraductal, Noninfiltrating; Carcinoma, Lobular; Endothelin-1; Female; Humans; Immunochemistry; Receptor, Endothelin A; Receptor, Endothelin B; Retrospective Studies

We have studied the role of endothelins (ET-1, ET-2 and ET-3) and ET receptors (ET-RA and ET-RB) in the invasive capacity of breast tumor cells, which express ET-1 and ET-2 as well as ET-RA and ET-RB. Of five human breast tumor cell lines tested, all expressed mRNAs for ET-1, ET-2, and ET-RB. ET-RA mRNA was expressed by four of five tumor cell lines. Breast tumor cells migrated toward ET-1 and ET-2 but not toward ET-3. Chemotaxis involved signaling via both receptors, and a pertussis toxin-sensitive p42/p44 mitogen-activated protein kinase (MAPK)-mediated pathway that could be inhibited by MAPK kinase (MEK)1/2 antagonists. Chemotaxis toward ETs did not involve p38 or stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) and was not inhibited by hypoxia. Incubation of tumor cells with ET-2 also increased chemotaxis toward the chemokines CXCL12 and CCL21. As well as inducing chemotaxis of tumor cells, ET-1 and ET-2 increased tumor cell invasion through Matrigel. Furthermore, stimulation of macrophage/tumor cell cocultures with ETs led to increased matrix metalloproteinase (MMP)-2 and -9 production by macrophages and a marked increase in invasion of tumor cells. Antagonism of either ET-RA or ET-RB decreased the invasion seen in ET-stimulated cocultures, as did a broad-spectrum MMP inhibitor. Immunohistochemical staining of human breast tumor sections showed increased ET and ET receptor protein expression by tumor cells in invasive ductal carcinoma compared with normal breast tissue or ductal carcinoma in situ. Furthermore, tumor cell ET and receptor expression was stronger at the invasive margin of invasive ductal carcinomas, in the lymphovascular space, and in lymph node metastases. ET expression often colocalized with ET-RB expression in all neoplastic tissue indicating a possible autocrine action of ETs. We suggest that expression of ETs and their receptors by human breast tumors, particularly in conjunction with a high macrophage infiltrate, may have a role in the progression of breast cancer and the invasion of tumor cells.

Topics: Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal; Cell Line, Tumor; Chemotaxis; Coculture Techniques; Endothelin-1; Endothelin-2; Humans; Isoenzymes; Macrophages; MAP Kinase Signaling System; Matrix Metalloproteinases; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Neoplasm Invasiveness; Receptor, Endothelin A; Receptor, Endothelin B; RNA, Messenger

Endothelins (ETs) are peptides expressed in many tumours which may stimulate angiogenesis and desmoplasia. Because ETs have not been extensively studied mammary neoplasia, we assessed ET protein and mRNA expression and receptor mRNA expression in normal and neoplastic breast tissues.. Tissues from five normal breasts, six fibroadenomas, seven ductal carcinomas in situ (DCIS) and 25 invasive carcinomas were stained with anti-ET-1 and anti-ET-3 antibodies and analysed using a grading system. ET-1, ET-3, ETA and ETB mRNA expression was assessed by quantitative RT-PCR from eight carcinomas and five normals. Weak staining for ET-1 and ET-3 was detected in all normals. Moderate to strong staining was seen in 72% and 64% of carcinomas for ET-1 and ET-3, respectively. Most fibroadenomas showed weak positivity for ET-1 (83%) and ET-3 (67%). ET-1 and ET-3 mRNA levels were upregulated in carcinomas compared with normal breast. No ETA mRNA was not detected in any tissue. ETB mRNA was detected in normal breast and was increased in carcinomas.. These results suggest that the ET system is altered in breast carcinomas and this may be of importance in the progression from in-situ to invasive carcinoma.

Topics: Blotting, Southern; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Endothelin-1; Endothelin-3; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Receptor, Endothelin B; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger