Researchers identify ‘exciting new target in prostate cancer’
MedWire News: Researchers have discovered a potential role for Cyr61 protein expression in characterizing hard-to-diagnose prostate cancer.
The researchers found significant up-regulation of Cyr61 in prostate cancer tissue compared with normal prostate tissue, and its presence was strongly associated with advanced disease (Gleason score 8 or higher).
“Cyr61 holds unique potential in that it gauges the extracellular environment, transmitting signals that alter downstream pathways involved in tumorigenesis, including proliferation and migration,” explain Robert Getzenberg, from The Johns Hopkins Hospital in Baltimore, Maryland, USA, and colleagues.
The team performed quantitative gene expression analysis to compare Cyr61 expression in prostate cancer tissue, with that found in benign prostatic hyperplasia and healthy donor prostate tissue.
Cyr61 expression was increased in the prostate cancer tissue compared with the healthy tissue, at 9.05 (relative mRNA abundance normalized to glucuronidase-β in tissue) versus 1.84.
Conversely, no evidence of increased Cyr61 expression was observed in benign prostatic hyperplasia tissue, report Getzenberg et al.
In a subsequent microarray analysis of 174 prostate tumor samples matched with normal prostate tissue adjacent to tumor tissue, significant up-regulation of Cyr61 was observed in the tumor tissue compared with the normal tissue.
On a Cyr61 staining scale where 0=normal tissue, 1=atrophy, 2=prostatic intraepithelial neoplasia, and 3=cancer, the researchers report staining intensity at 1 or greater, 2 or greater, and 3 or greater in 98.3%, 85.1%, and 60.9% of cancer spots, and in 60.3%, 21.3%, and 1.7% of normal spots, respectively.
In addition, Cyr61 staining was higher in men with a Gleason score of 8 or greater, than in those with a Gleason score of less than 8.
After comparing primary prostate cancer with metastatic lesions, the researchers found higher Cyr61 expression in the primary tumors. The team suggest this indicates that the role of Cyr61 “is likely important for prostate cancer development and/or maintenance, rather than metastasis or invasion.”
They conclude in The Journal of Urology: “Cyr61 up-regulation in prostate cancer in our study focuses the need for further analysis of the role of Cyr61 in prostate cancer and normal prostate tissues.”
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By Sarah Guy