[show abstract][hide abstract] ABSTRACT: Oxidative stress-modulated signaling pathways have been implicated in carcinogenesis and therapy resistance. The lens epithelium derived growth factor p75 (LEDGF/p75) is a transcription co-activator that promotes resistance to stress-induced cell death. This protein has been implicated in inflammatory and autoimmune conditions, HIV-AIDS, and cancer. Although LEDGF/p75 is emerging as a stress survival oncoprotein, there is scarce information on its expression in human tumors. The present study was performed to evaluate its expression in a comprehensive panel of human cancers. Transcript expression was examined in the Oncomine cancer gene microarray database and in a TissueScan Cancer Survey Panel quantitative polymerase chain reaction (Q-PCR) array. Protein expression was assessed by immunohistochemistry (IHC) in cancer tissue microarrays (TMAs) containing 1735 tissues representing single or replicate cores from 1220 individual cases (985 tumor and 235 normal tissues). A total of 21 major cancer types were analyzed. Analysis of LEDGF/p75 transcript expression in Oncomine datasets revealed significant upregulation (tumor vs. normal) in 15 out of 17 tumor types. The TissueScan Cancer Q-PCR array revealed significantly elevated LEDGF/p75 transcript expression in prostate, colon, thyroid, and breast cancers. IHC analysis of TMAs revealed significant increased levels of LEDGF/p75 protein in prostate, colon, thyroid, liver and uterine tumors, relative to corresponding normal tissues. Elevated transcript or protein expression of LEDGF/p75 was observed in several tumor types. These results further establish LEDGF/p75 as a cancer-related protein, and provide a rationale for ongoing studies aimed at understanding the clinical significance of its expression in specific human cancers.
PLoS ONE 01/2012; 7(1):e30132. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: The peroxiredoxins (PRDXs) are emerging as regulators of antioxidant defense, apoptosis, and therapy resistance in cancer. Because their significance in prostate cancer (PCa) is unclear, we investigated their expression and clinical associations in PCa.
Transcript expression of PRDX1-6 in PCa was evaluated in cancer gene microarray datasets, whereas protein expression was evaluated by immunoblotting in prostate cell lines, and by immunohistochemistry (IHC) in prostate tissue microarrays (TMAs) containing tumor (n = 80) and control (n = 17) tissues. PRDX3 was also analyzed in TMAs containing PCa tissues from African-American and Caucasian patients (n = 150 per group). PRDX expression was correlated with patients' clinicopathologic characteristics.
Analysis of PRDX expression in cancer microarray datasets revealed consistent upregulation (tumor vs. normal) of PRDX3 and 4. All PRDXs exhibited elevated protein expression in PCa cell lines, compared with non-tumor cells. IHC revealed significant overexpression of PRDX3 and 4 in PCa, associated with age, increased prostate specific antigen (PSA), tumor stage, or Gleason score. High PRDX3 staining was associated with early age and elevated Gleason score at time of radical prostatectomy in African-American but not in Caucasian patients with PCa. PSA recurrence free survival in patients with low PRDX3 tumor expression was significantly longer in Caucasians compared to African-Americans, but no difference was detected for high expression.
PRDXs exhibit differential expression in prostate tumors, with PRDX3 and 4 consistently upregulated. Their role in PCa development, and their potential as biological determinants of PCa health disparities and novel therapeutic targets, deserve further investigation.
The Prostate 10/2010; 71(7):755-65. · 3.84 Impact Factor