Induced overexpression of OCT4A in human embryonic stem cells increases cloning efficiency.

Our knowledge of the molecular mechanisms underlying human embryonic stem cell (hESC) self-renewal and differentiation is incomplete. The level of octamer-binding transcription factor 4 (Oct4), a critical regulator of pluripotency, is precisely controlled in mouse embryonic stem cells. However, studies of human OCT4 are often confounded by the presence of three isoforms and six expressed pseudogenes, which has complicated the interpretation of results.

Molecular characterization of the human NANOG protein.

NANOG is a key transcriptional regulator of pluripotent stem cell (PSC) self-renewal. NANOG occupies promoters that are active and others that are repressed during self-renewal; however, the mechanisms by which NANOG regulates transcriptional repression and activation are unknown. We hypothesized that individual protein domains of NANOG control its interactions with both the promoters and its coregulators.

Detection of chromosomal instability in paired breast surgery and ductal lavage specimens by interphase fluorescence in situ hybridization.

Purpose: Ductal lavage is a new modality for collecting exfoliated breast cells with the goal of detecting early neoplasia. The purpose of our study was to evaluate the correlation between cancer-associated abnormalities in breast lesions and exfoliated breast cells collected by ductal lavage.

Experimental Design: We performed histopathologic, cytologic, and molecular cytogenetic analyses on 39 paired cases of surgically excised breast lesions and ductal lavage specimens collected immediately before surgery.

Immunocytochemical analysis of breast cells obtained by ductal lavage.

Background: Intraductal breast fluids containing exfoliated mammary epithelial cells can be harvested from the breast by ductal lavage to screen for disease-associated cytologic abnormalities. In addition to epithelial cells, breast fluids contain large numbers of mammary foam cells, and the tissue of origin of these foam cells has been the subject of controversy for many years. Immunocytochemical, morphologic, and molecular studies variously have supported a mammary epithelial origin versus a histiocytic origin for this cell type.