Prostate cancer with different ERG status may show different FOXP3-positive cell numbers

Prostatic carcinoma is the most frequent cancer in males in the Western world. A significant proportion of these cancers have a recurrent translocation involving ETS family genes, which leads to the overexpression of ERG transcription factor. Prostate cancers, which bear this mutation, differ in a number of features, including tumor microenvironment. One of the components of the tumor microenvironment is FOXP3 positive lymphocytes, which may participate in breaking immunosurveillance and promoting tumor growth. The aim of the study was to analyze the relationships between ERG expression, number of FOXP3 positive cells and other features of the tumor. The study group consisted of 65 cases. Tissue microarrays composed of 2 mm tissue cores were used for immunohistological evaluation. Immunohistochemistry for ERG and FOXP3 was performed according to the routinely applied protocol. The FOXP3 positive cells were counted and the results were expressed as the number of cells per mm2. The average number of FOXP3 positive cells was 33.30/mm2 for all cases, 21.43/mm2 for the ERG negative and 42.28/mm2 for the ERG positive group (p < 0.02). There were no significant relationships between FOXP3 positive cell count and any other parameters studied. Our results suggest that the immune response may differ between ERG negative and ERG positive prostatic carcinomas

Mast cells influence neoangiogenesis in prostatic cancer independently of ERG status

A significant proportion of prostatic adenocarcinomas show recurrent translocation leading to ERG expression. Previously we found that ERG+ cases have higher microvessel density than negative ones. One factor influencing angiogenesis in cancer is mast cells. The aim of the present study was to evaluate the relationship between microvessels, mast cells and ERG status. Tissue microarrays prepared from 113 radical prostatectomy specimens were analyzed with immunohistochemistry for CD31, tryptase and chymase. Vascular profiles and tryptase-positive and chymase-positive cells were counted. The average number of tryptase-positive cells was 28.93/mm 2 and chymase-positive cells 9.91/mm 2 . The average number of CD31+ vascular profiles was 352.66/mm 2 . The average number of tryptase-positive cells was 26.35/mm 2 for ERG– cases and 32.12/mm 2 for ERG+ cases. The average number of chymase-positive cells was 8.14/mm 2 for ERG– cases and 12.06/mm 2 for ERG+ cases. The average number of CD31+ vascular profiles was 321.34/mm 2 for ERG– cases and 390.74/mm 2 for ERG+ cases. The number of CD31+ vascular profiles was positively correlated with the number of tryptase-positive and chymase-positive cells (R = 0.26 and R = 0.20). In summary, we demonstrated an interrelationship between mast cells, microvascular density and ERG status in prostatic carcinoma