Design considerations for array CGH to oligonucleotide arrays.

Background: Representational oligonucleotide microarray analysis has been developed for detection of single nucleotide polymorphisms and/or for genome copy number changes. In this process, the intensity of hybridization to oligonucleotides arrays is increased by hybridizing a polymerase chain reaction (PCR)-amplified representation of reduced genomic complexity. However, hybridization to some oligonucleotides is not sufficiently high to allow precise analysis of that portion of the genome.

Altered expression of a cell-cycle suppressor gene, Tob-1, in endometriotic cells by cDNA array analyses.

Objective: Interleukin (IL)-1beta, a product of activated peritoneal macrophages, is a central cytokine coordinating neovascularization and monocyte chemotaxis in endometriotic implants. To evaluate the effects of this cytokine on normal endometrial stromal cells and endometriotic stromal cells we performed cDNA expression array analyses before and after exposure to IL-1beta.

Design: Nested case-control study of women with and without laparoscopic evidence of endometriosis.

PIK3CA is implicated as an oncogene in ovarian cancer.

Ovarian cancer is the leading cause of death from gynecological malignancy and the fourth leading cause of cancer death among American women, yet little is known about its molecular aetiology. Studies using comparative genomic hybridization (CGH) have revealed several regions of recurrent, abnormal, DNA sequence copy number that may encode genes involved in the genesis or progression of the disease. One region at 3q26 found to be increased in copy number in approximately 40% of ovarian and others cancers contains PIK3CA, which encodes the p110alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3-kinase).

Isolation of genomic fragments from polymorphic regions by representational difference analysis.

Representational difference analysis is an effective technique for isolating the differences between two nearly identical genomes. We have found the technique to be extremely valuable in our analyses of mouse germline mutations. We also present several technical improvements in the procedure that make it more efficient and reliable.

Recovery of probes linked to the jcpk locus on mouse chromosome 10 by the use of an improved representational difference analysis technique.

Representational difference analysis (RDA) is a subtractive hybridization technique by which the differences between two complex genomes can be isolated. An improved version of this technique was used to isolate DNA segments that map to a narrow genetic region adjacent to the jcpk locus on Chromosome 10 of the mouse. A mutation at this locus acts recessively and causes an early onset polycystic kidney disease.

Comparison of the ability of normal mouse mammary tissues and mammary adenocarcinoma to cleave rat prolactin.

Previous studies have shown that target tissues cleave rat prolactin (rPRL) to form a two-chain derivative that yields approximately 16- and approximately 6-kDa fragments upon reduction. Both cleaved rPRL and the purified 16-kDa fragment have novel biological activities. Thus, cleavage may be of physiological significance.

Cleavage of rat prolactin occurs within rat mammary tissue, and the cleaved form is present in serum but not in milk.

The present study was undertaken to determine whether cleavage of rat prolactin (rPRL) occurs within rat mammary tissue and to investigate whether the cleaved form and its 16-kDa amino terminal fragment are present in rat serum and milk. The relative abundance of the different forms of rPRL was determined by SDS-PAGE and immunoblot analysis using an antiserum to the 16-kDa fragment. Explants of mammary glands from lactating rats were incubated with intact rPRL.

Mass spectrometric analysis of the fragments produced by cleavage and reduction of rat prolactin: evidence that the cleaving enzyme is cathepsin D.

The site(s) at which mammary tissue enzymatically cleaves rat (r) PRL, and the possibility that the cleaving activity is cathepsin D, were investigated using mass spectrometry and enzyme inhibitors. Cleavage of intact rPRL [22,566 atomic mass units (amu)] by either mammary gland-conditioned medium or cathepsin D (both at pH 3) reduced the mass of the molecule by 397 amu. Subsequent reduction of the large rPRL fragment cleaved by either method generated two fragments of 16,364 and 5808 amu.

Processing of rat prolactin by rat tissue explants and serum in vitro.

Previous work has shown that enzymes from rat liver or mammary gland can cleave rat (r) PRL to form a two-chain derivative that yields approximately 16- and 7-kilodalton (kDa) fragments upon reduction. Both cleaved rPRL and the purified 16-kDa fragment have maintained biological activity. Thus, cleavage may be of physiological significance.

Evidence for hepatic involvement in the regulation of amphibian development by prolactin.

Hormonal control of amphibian development involves thyroid hormones (TH), which promote metamorphosis, and prolactin (PRL), which antagonizes the effects of TH and promotes larval growth. Although the liver is not considered to be a regulator of developmental processes such as metamorphosis, it secretes a PRL-synergizing factor (synlactin) in response to PRL. We explored the possibility that the liver may participate in the antimetamorphic actions of PRL in Rana catesbeiana.