Digital expression profiles of the prostate androgen-response program
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY
Authors: Clegg, N; Eroglu, B; Ferguson, C; Arnold, H; Moorman, A; Nelson, PS
Abstract
The androgen receptor (AR) and cognate ligands regulate vital aspects of prostate cellular growth and function including proliferation, differentiation, apoptosis, lipid metabolism, and secretory action. In addition, the AR pathway also influences pathological processes of the prostate such as benign prostatic hypertrophy and prostate carcinogenesis. The pivotal role of androgens and the AR in prostate biology prompted this study with the objective of identifying molecular mediators of androgen action. Our approach was designed to compare transcriptomes of the LNCaP prostate cancer cell line under conditions of androgen depletion and androgen stimulation by generating and comparing collections of expressed sequence tags (ESTs). A total of 4400 ESTs were produced from LNCaP cDNA libraries and these ESTs assembled into 2486 distinct transcripts. Rigorous statistical analysis of the expression profiles indicated that 17 genes exhibited a high probability (P > 0.9) of androgen-regulated expression. Northern analysis confirmed that the expression of KLK3/PSA, FKBP5, KRT18. DKFZP564K247, DDX15, and HSP90 is regulated by androgen exposure. Of these. only KLK3/PSA is known to be androgen-regulated while the other genes represent new members of the androgen-response program in prostate epithelium. LNCaP gene expression profiles defined by two independent experiments using the serial analysis of gene expression (SAGE) method were compared with the EST profiles. Distinctly different expression patterns were produced from each dataset. These results are indicative of the sensitivity of the methods to experimental conditions and demonstrate the power and the statistical limitations of digital expression analyses. (C) 2002 Elsevier Science Ltd. All rights reserved.
Global gene expression of the inner cell mass and trophectoderm of the bovine blastocyst
BMC DEVELOPMENTAL BIOLOGY
Authors: Ozawa, Manabu; Sakatani, Miki; Yao, JiQiang; Shanker, Savita; Yu, Fahong; Yamashita, Rui; Wakabayashi, Shunichi; Nakai, Kenta; Dobbs, Kyle B.; Sudano, Mateus Jose; Farmerie, William G.; Hansen, Peter J.
Abstract
Background: The first distinct differentiation event in mammals occurs at the blastocyst stage when totipotent blastomeres differentiate into either pluripotent inner cell mass (ICM) or multipotent trophectoderm (TE). Here we determined, for the first time, global gene expression patterns in the ICM and TE isolated from bovine blastocysts. The ICM and TE were isolated from blastocysts harvested at day 8 after insemination by magnetic activated cell sorting, and cDNA sequenced using the SOLiD 4.0 system. Results: A total of 870 genes were differentially expressed between ICM and TE. Several genes characteristic of ICM (for example, NANOG, SOX2, and STAT3) and TE (ELF5, GATA3, and KRT18) in mouse and human showed similar patterns in bovine. Other genes, however, showed differences in expression between ICM and TE that deviates from the expected based on mouse and human. Conclusion: Analysis of gene expression indicated that differentiation of blastomeres of the morula-stage embryo into the ICM and TE of the blastocyst is accompanied by differences between the two cell lineages in expression of genes controlling metabolic processes, endocytosis, hatching from the zona pellucida, paracrine and endocrine signaling with the mother, and genes supporting the changes in cellular architecture, stemness, and hematopoiesis necessary for development of the trophoblast.