Expression of Group IIa Secretory Phospholipase A2 Increases with Prostate Tumor Grade

• Published in: Clinical cancer research Vol. 7; no. 12; pp. 3857 - 3861
• Main Authors: GRAFF, Jeremy R, KONICEK, Bruce W, DEDDENS, James A, CHEDID, Marcio, HURST, Bernadette M, COLLIGAN, Bruce, NEUBAUER, Blake Lee, CARTER, Harry W, CARTER, Julia H
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 01.12.2001
• Subjects: Androgens - pharmacology; Arachidonic Acid - metabolism; Biological and medical sciences; Cell Division; Disease Progression; Humans; Immunohistochemistry; Isoenzymes - metabolism; Male; Medical sciences; Nephrology. Urinary tract diseases; Phospholipases A - metabolism; Phospholipases A2; Prostatic Hyperplasia - enzymology; Prostatic Hyperplasia - pathology; Prostatic Neoplasms - enzymology; Prostatic Neoplasms - pathology; Transplantation, Heterologous; Tumor Cells, Cultured; Tumors of the urinary system; Urinary tract. Prostate gland; Secretory component; Histological grading; Carcinoma; Prostate disease; Gene product; Hyperplasia; Tumoral tissue; Phospholipid; Gene overexpression; Esterases; Arachidonic acid; Carcinogenesis; Established cell line; Tumor progression; Male genital diseases; Tumor cell; Human; Urinary system disease; Premalignant lesion; Enzyme; Malignant tumor; Cell differentiation; Gene expression; Metabolism; In vitro; Phospholipase A; Carboxylic ester hydrolases; Hydrolases; Prostate
• ISSN: 1078-0432; 1557-3265

Purpose: Arachidonate release contributes to prostate tumor progression as arachidonate is metabolized into prostaglandins and leukotrienes, potent mediators of immune suppression, cellular proliferation, tumor motility, and invasion. The group IIa sPLA2 (sPLA2-IIa) can facilitate arachidonate release from cellular phospholipids. We therefore sought to determine whether sPLA2-IIa expression might be related to the development or progression of prostatic adenocarcinoma (CaP). Experimental Design: sPLA2-IIa expression was examined by Western blot analyses of CaP cells and xenografts and by immunohistochemistry of benign prostatic hyperplasias and primary human CaPs ( n = 101) using a sPLA2-IIa-specific polyclonal antibody. Results: sPLA2-IIa expression was increased dramatically in the androgen-independent CWR-22R and LNAI CaP cells versus the androgen-dependent CWR-22 and LNCaP cells. Immunohistochemical analyses revealed that sPLA2-IIa expression was also significantly increased with CaP development and advancing disease (trend analysis; Pearson correlation coefficient, P = 0.016). High-grade CaPs showed intense, uniform staining for sPLA2-IIa that was significantly different from that in adjacent benign prostatic hyperplasias (Fisher’s exact test, P = 0.021) or low-grade CaP ( P = 0.013), both of which showed only focal or weak sPLA2-IIa staining. Further, uniform sPLA2-IIa expression was directly related to the increased proliferative index that typifies advancing disease ( P = 0.001). Most significantly, enhanced sPLA2-IIa expression was inversely related to 5-year patient survival ( P = 0.015). Conclusions: These data show that sPLA2-IIa expression increases with progression to androgen-independence and is highest in the most poorly-differentiated, highest-grade primary human CaP samples.