title: Identification of PCAG1 as a novel prostate cancer-associated gene.
abstract: The aim of the present study was to identify a new prostate cancer‑associated             gene and analyze its expression pattern. Comprehensive expression analysis of             expressed sequence tags (ESTs) and microarray data and serial analysis of gene             expression (SAGE) were conducted to screen in silico for candidate prostate cancer‑associated             genes. Reverse transcription (RT)-PCR was performed to validate prostate cancer             specificity. Prostate cancer‑associated gene 1 (PCAG1) was identified. The expression             of PCAG1 mRNA and protein was evaluated in common human normal tissues, common             malignant tumors, prostate adenocarcinoma and paired adjacent normal prostate             tissues. An immunofluorescence assay was conducted to determine the subcellular             location of PCAG1. PCAG1 mRNA was absent in the 15 pooled normal tissues (including             normal prostate tissue) but registered at low levels in the spleen tissue (+).             By contrast, PCAG1 mRNA was significantly higher than in the adjacent normal tissues             in each of the 14 cases of prostate cancer, with ~50% scoring a high degree of             expression (+++). Of the 32 types of normal tissues, 29 (including normal prostate             tissue) demonstrated negative PCAG1 protein staining while the remaining tissues             of the adrenal gland, parathyroid gland and liver expressed low levels. While             18/20 cases of prostate adenocarcinoma showed positive expression results, PCAG1             protein expression in the remaining types of cancer was scarce when present at             all; only 41/380 other cancer cases demonstrated positive results at a low level.             The most substantial PCAG1-positive expression results were identified by cytoplasmic             staining in 36/38 prostate adenocarcinoma cases, with 10 cases showing high expression             levels, 20 showing medium levels and 6 showing low levels. In the paired adjacent             normal prostate tissues, only 3/38 cases showed low level positive staining, while             35/38 cases were negative. Immunofluorescent staining of the human prostate cancer             PC3 cell line showed positive PCAG1 expression results in the mitochondria. The             present study demonstrated that while PCAG1 mRNA was highly expressed in prostate             cancer tissues, it was almost absent in all common normal tissues and paired adjacent             normal prostate tissues. Furthermore, PCAG1 protein was also highly expressed             in prostate cancer tissues, while few common normal tissues, other common malignant             tumors and paired adjacent normal prostate tissues had even low levels of expression.             Clarification of the function and transcriptional mechanism of PCAG1 may aid the             elucidation of the mechanisms of carcinogenesis and progression of prostate cancer.             The unique expression pattern of PCAG1 suggests its potential in certain clinical             applications.
authors.affiliation: Department of Urology, Peking University Shenzhen Hospital, Shenzhen, PR China. yqlord@163.com
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Lai
authors.forename: Zuhu
authors.initials: Z
authors.lastname: Yu
authors.forename: Yadong
authors.initials: Y
authors.lastname: Wang
authors.forename: Jiongxian
authors.initials: J
authors.lastname: Ye
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000311:Adrenal Glands / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D020224:Expressed Sequence Tags; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010280:Parathyroid Glands / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D010088:Oxidoreductases; C467741:STEAP2 protein, human