Expression analysis of Y chromosome genes in human prostate cancer.

PURPOSE: We hypothesized that alterations in Y chromosome gene expression may be associated with prostate cancer. To test this hypothesis we analyzed the expression of 19 Y chromosome genes in benign and malignant prostate tissue. MATERIALS AND METHODS: To study the expression of Y chromosome genes RNA was extracted from prostate cancer and benign prostatic hyperplasia (BPH) tissue as well as from prostate cancer cell lines. RNA was reverse transcribed and polymerase chain reaction amplified using specific primers. These primers were designed for each gene sequence obtained from the gene data bank. We analyzed 19 Y chromosome genes using 6 cell lines, 7 BPH and 7 prostate cancer tissues. Normal testis RNA served as a positive control. RESULTS: Of the 19 genes analyzed in cell lines BPH-1 cells expressed the RPS4Y, USP9Y, TMSB4Y and DBY genes; DUPro expressed RPS4Y, USP9Y, TMSB4Y, DBY and UTY; DU145 expressed DAZ, RPS4Y, USP9Y, TMSB4Y, DBY, EIAFIY, PRKY and SMCY; LNCaP expressed TSPY, SRY, BPY1, PRY, DAZ, RBMIH, RPS4Y, DBY, EIAFIY, PRKY and SMCY; ND1 expressed DAZ, RPS4Y, USP9Y, TMSB4Y, DBY, EIAFIY, PRKY and SMCY; and PC3 expressed RPS4Y, USP9Y and DBY. BPH tissue expressed the SRY, PRY, DBY, PRKY, RPS4Y, TMSB4Y, USP9Y and ZFY genes. Prostate cancer tissue expressed the PRY, TSPY, USP9Y, UTY, DBY, SMCY, ZFY, EIAFIY, TMSB4Y and RPS4Y genes. CONCLUSIONS: The differential expression of Y chromosome genes in prostate cancer, BPH tissue and prostate cancer cell lines indicates that they may have a role in prostate cancer.

The peroxisome proliferator response element (PPRE) present at positions -681/-669 in the rat liver 3-ketoacyl-CoA thiolase B gene functionally interacts differently with PPARalpha and HNF-4.

Although previous data showed that the putative thiolase B PPRE located at -681/-669 bind the PPARalpha-RXRalpha heterodimer in vitro (Kliewer et al. (1992) Nature 358, 771-774), there is no evidence about the functional role of this element. By gel mobility-shift assay, we found an interaction of this PPRE with not only PPARalpha but also with HNF-4. By transfection of cells with the putative PPRE-driven luciferase reporter vector and PPARalpha, we found no significant activation of the luciferase gene expression, in contrast to the case with reporter expression driven by the PPRE of the peroxisomal bifunctional enzyme. On the other hand, HNF-4 activated the luciferase gene expression driven by the putative thiolase PPRE. We suggest that the thiolase B gene induction by peroxisome proliferators employs either another PPRE or this one in combination with other gene regulatory element(s) to lead to the strong gene expression observed in the presence of peroxisome proliferators.

Studies on regulation of the peroxisomal beta-oxidation at the 3-ketothiolase step. Dissection of the rat liver thiolase B gene promoter.

The peroxisomal 3-oxoacyl-CoA thiolase (thiolase) is the last enzyme involved in the beta-oxidation of fatty acids. The enzyme cleaves long chain fatty acyl-CoA to generate acetyl-CoA and shortened acyl-CoA. The enzyme is nuclear encoded, synthesized in the cytoplasm and transported into peroxisomes. The thiolase B gene is inducible by the peroxisome proliferator compounds, like other genes involved in beta-oxidation of fatty acids in peroxisomes. The importance of studying thiolase is that it generates acetyl-CoA which is the precursor for the synthesis of molecules like cholesterol and fatty acids. The structural and functional analysis of thiolase at molecular level may add to the knowledge of fatty acid metabolism and further the obesity phenomenon. It is known that several genes mediate lipid homeostasis in target organs like liver, adipose tissue and are regulated by peroxisome proliferator activated receptors (PPAR alpha and PPAR gamma). To elucidate the mechanism of induction of rat liver thiolase B gene, an upstream 2.8 kb fragment containing promoter element has been subcloned and partially sequenced. The sequence analysis revealed a putative PPRE (Peroxisome Proliferator Response Element) of AGACCT T TGAACC sequence at -681 to -668 [Kliever et al. (1992) Nature 358:771-774]. By transient expression of a luciferase reporter gene in HeLa cells, we conclude that the identified PPRE could be functional in induction of thiolase B gene, but other sequences of genes might be involved.