Effect of Androgen Blockade on HER-2 and Matrix Metalloproteinase-2 Expression on Bone Marrow Micrometastasis and Stromal Cells in Men with Prostate Cancer

Introduction. HER-2 has been associated with castrate resistant prostate cancer and matrix metalloproteinase-2 (MMP-2) in the dissemination and invasion of tumor cells as well as activating angiogenesis. We present an immunocytochemical study of the effect of androgen blockade on the expression of HER-2 and MMP-2 in bone marrow micrometastasis and the surrounding stromal cells in men with prostate cancer.Methods and Patients. A cross-sectional study of men with prostate cancer. Touch preps were obtained from bone marrow biopsies of men with prostate cancer, before and after radical prostatectomy and during androgen blockade. Micrometastasis detected with anti-PSA immunocytochemistry underwent processing with anti-HER-2 and anti-MMP-2 immunocytochemistry. Patients were defined as HER-2 positive or negative, MMP-2 negative or an MMP-2 pattern described as border or central and stromal MMP-2 defined as positive or negative. The expression of the biomarkers was compared before and after primary treatment and during androgen blockade in relation to the serum PSA at the time of sampling and duration of androgen blockade.Results. 191 men participated, 35 men before surgery and 43 after surgery; there were no significant differences in HER-2 expression between groups, there was no MMP-2 expression centrally or stromal expression of MMP-2. In men with androgen blockade, HER-2 expression was significantly higher; there was a trend for increasing HER-2 expression up to 5 years; central MMP-2 expression significantly increased after 3 years, while stromal MMP-2 significantly increased after 6 years. MMP-2 expression both in micrometastasis and stroma was significantly associated with HER-2 expression. Expression of MMP-2 at the border of the micrometastasis was not associated with HER-2 expression and occurred in the absence of androgen blockade.Conclusions. Androgen blockade decreases serum PSA by eliminating HER-2 negative prostate cancer cells. However, there is early selection of HER-2 positive cancer cells which leads to androgen independence and to increased expression of MMP-2 activity in the micrometastasis. The increased MMP-2 activity in the micrometastasis increases the expression of MMP-2 in the surrounding stromal cells and thus could promote angiogenesis and tumor growth resulting in macrometastatic androgen independent disease.

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Differential Expression of Matrix Metalloproteinase-2 Expression in Disseminated Tumor Cells and Micrometastasis in Bone Marrow of Patients with Nonmetastatic and Metastatic Prostate Cancer: Theoretical Considerations and Clinical Implications—An Immunocytochemical Study

Bone Marrow Research ◽

10.1155/2012/259351 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 13

Author(s):

Nigel P. Murray ◽

Eduardo Reyes ◽

Pablo Tapia ◽

Leonardo Badínez ◽

Nelson Orellana

Keyword(s):

Prostate Cancer ◽

Bone Marrow ◽

Matrix Metalloproteinase ◽

Tumor Cells ◽

Gleason Score ◽

Stromal Cells ◽

Disseminated Tumor Cells ◽

Matrix Metalloproteinase 2 ◽

Low Grade ◽

Immunocytochemical Study

Matrix metalloproteinase-2 (MMP-2) is important in the dissemination and invasion of tumor cells and activates angiogenesis. We present an immunocytochemical study of MMP-2 expression in circulating prostate cells (CPCs), disseminated tumor cells (DTCs), and micrometastasis (mM) in bone marrow of men with prostate cancer. Methods and Patients. Tumor cells were identified with anti-PSA immunocytochemistry. Positive samples underwent processing with anti-MMP-2, its expression was compared with Gleason score, concordance of expression, and metastatic and nonmetastatic disease. Results. 215 men participated, CPCs were detected in 62.7%, DTCs in 62.2%, and mM in 71.4% in nonmetastatic cancer; in metastatic cancer all had CPCs, DTCs, and mM detected. All CPCs and DTCs expressed MMP-2; in mM MMP-2 expression was positively associated with increasing Gleason score. MMP-2 expression in CPCs and DTCs showed concordance. In low grade tumors, mM and surrounding stromal cells were MMP-2 negative, with variable expression in high grade tumors; in metastatic disease, both mM and stromal cells were MMP-2 positive. Conclusions. CPCs and DTCs are different from mM, with inhibition of MMP-2 expression in mM of low grade tumors. With disease progression, MMP-2 expression increases in both mM and surrounding stromal cells, with implications for the use of bisphosphonates or MMP-2 inhibitors.

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