Expression analysis of Thrombospondin 2 in prostate cancer and benign prostatic hyperplasia
Matos AR, Coutinho-Camillo CM, Thuler LC, Fonseca FP, Soares FA, Silva EA, Gimba ER. Exp Mol Pathol. 2013 Mar 4. pii: S0014-4800(13)00032-4. doi: 10.1016/j.yexmp.2013.02.002. [Epub ahead of print]

Source

Programa de Carcinogênese Molecular/Programa de Pós Graduação Stricto Sensu em Oncologia do Instituto Nacional de Câncer (INCa), CPQ, Rio de Janeiro, RJ, Brasil.

Abstract

Thrombospondin 2 (TSP2) is a protein with important roles in different tumor types, mainly related to tumor inhibition. However, there are limiting data regarding TSP2 in prostate cancer (PCa) and benign prostate hyperplasia (BPH). We aimed to investigate TSP2 transcript and protein expression in tumoral and non-tumoral prostate tissues and cell lines, and its implications for PCa diagnosis and progression. TSP2 transcript expression was evaluated by real time PCR in PCa and BPH tissue samples and in tumoral and non-tumoral cells lines. TSP2 protein expression analysis was conducted by immunohistochemistry in a tissue microarray (TMA) containing PCa and BPH tissue samples. TSP2 transcript was down-regulated in PCa tissue samples and cell lines, when compared to BPH and non-tumoral samples (p<0.01). Receiving Operating Curve (ROC) analysis demonstrated that TSP2 transcript levels can better distinguish PCa from BPH tissue samples (p<0.01) than serum PSA levels (p=0.299). TSP2 protein expression has been observed in the cytoplasm of both PCa and BPH epithelial and stromal compartments. TSP2 stromal staining scores were significantly lower in PCa than in BPH tissues (p<0.01), while similar TSP2 epithelial staining patterns were observed in both diseases. Notably, the TSP2 epithelial staining score was significantly correlated to vascular invasion and biochemical recurrence in PCa tissue samples (p<0.05). Our data indicate that TSP2 is down-regulated at PCa tissues and cell lines, especially at stroma compartment, which could be related to PCa progression. TSP2 levels could potentially be applied for differential PCa and BPH diagnosis.