In vivo MRI volumetric measurement of prostate regression and growth in mice

Backgroun

Androgen Regulation of Gene Expression Associated with Cell Growth and Neural Plasticity: Studies in Songbird Brain and the S115 Cell Line

In order to characterize androgens\u27 effects on the brain and behavior I identified the canary cDNA coding for the nuclear receptor for androgen. The sequence is very conserved over functional domains, but shows some divergence from the only other sequences known, those for rodents and man. The AR mRNA can be localized by in situ hybridization in the canary to the testis and the song nuclei HVc, RA, and MAN. The AR mRNA is regulated by androgens in the periphery in a tissue specific manner. Using a sensitive semi-quantitative per assay, regulation of the AR mRNA by androgen treatment and by natural fluctuations of circulating androgens is seen in the song control nucleus HVc. I used the information about receptor location and the timing of androgen effects to examine androgen induced changes in genes likely be involved in neuronal plasticity. I cloned the canary homolog of the c-jun proto-oncogene, and confirmed its identity based on complete conservation of the important functional domains. I prepared RNA from steroid responsive parts of the brain from ovariectomized canaries treated with testosterone using a simple dot hybridization assay. I could detect a small but rapid induction by androgen of c-jun and two other proto-oncogenes (c-myc and n-myc) in RNA from tissue containing HVc and surrounding telencephalon. Because of this lack of a more dramatic effect in the complex tissue of the brain, I also quantified changes in gene expression induced by androgens in a simpler system. Acting in relative isolation, testosterone can dramatically increase the rate of proliferation of the cells, while estradiol is without effect. Testosterone can increase the mRNA levels of several structural genes, including homologs of genes regulated in the canary brain, and represses several transcription factors in addition to its own receptor. Testosterone also interacts synergistically with the Ca++ ionophore A23I87 to induce c-myc and histone H1 expression, where neither alone will do so. In addition, androgen pretreatment represses the TPA-induced increase of these same genes

Laminated microfluidic system for small sample protein analysis

We describe a technology based on lamination that allows for the production of highly integrated 3D devices suitable for performing a wide variety of microfluidic assays. This approach uses a suite of microfluidic coupons (“microfloupons”) that are intended to be stacked as needed to produce an assay of interest. Microfloupons may be manufactured in paper, plastic, gels, or other materials, in advance, by different manufacturers, then assembled by the assay designer as needed. To demonstrate this approach, we designed, assembled, and characterized a microfloupon device that performs sodium-dodecyl-sulfate polyacrylamide gel electrophoresis on a small sample of protein. This device allowed for the manipulation and transport of small amounts of protein sample, tight injection into a thin polyacrylamide gel, electrophoretic separation of the proteins into bands, and subsequent removal of the gel from the device for imaging and further analysis. The microfloupons are rugged enough to handle and can be easily aligned and laminated, allowing for a variety of different assays to be designed and configured by selecting appropriate microfloupons. This approach provides a convenient way to perform assays that have multiple steps, relieving the need to design highly sophisticated devices that incorporate all functions in a single unit, while still achieving the benefits of small sample size, automation, and high speed operation

CHESS suppresses fat signal artifact and facilitates discrimination between ventral and dorsal-lateral lobes

<p><b>Copyright information:</b></p><p>Taken from "In vivo MRI volumetric measurement of prostate regression and growth in mice"</p><p>http://www.biomedcentral.com/1471-2490/7/12</p><p>BMC Urology 2007;7():12-12.</p><p>Published online 24 Jul 2007</p><p>PMCID:PMC1945027.</p><p></p> T2- weighted MRI. : Magnification of the central 64 × 64 pixel square, indicated by the white box in . White arrow in A and black arrows in illustrate the shift of the signal derived from fat. The locations of the prostate (P), ureter (U) and abdominal fat (F) are indicated. : T2-weighted image acquired using CHESS. : Magnification as in . White arrows indicate ventral prostate (VP) and dorsal-lateral prostate (DLP). : Volume of the VP (solid bars) and DLP (grey bars) of normal mice determined using CHESS images, as in Figure 1F

MR-CHESS imaging of prostate re-growth during androgen supplementation of castrated mice

<p><b>Copyright information:</b></p><p>Taken from "In vivo MRI volumetric measurement of prostate regression and growth in mice"</p><p>http://www.biomedcentral.com/1471-2490/7/12</p><p>BMC Urology 2007;7():12-12.</p><p>Published online 24 Jul 2007</p><p>PMCID:PMC1945027.</p><p></p> Prostate from b7m1 following castration and DHT treatment. : day 0 (16 days following castration); : 2 days DHT treatment; : 4 days DHT treatment; : 9 days DHT treatment; : 12 days DHT treatment; : 16 days DHT treatment. Second column (-) as in Figure 4. : Plot of prostate volume during re-growth of the ventral prostates of two individual mice. Triangle symbols represent the volume of the prostate of b5m2, circles represent the volume of the VP of b7m1 and squares represent the volume of the DLP of b7m1

TNF Signaling Is Required for Castration-Induced Vascular Damage Preceding Prostate Cancer Regression

The mainstay treatment for locally advanced, recurrent, or metastatic prostate cancer (PrCa) is androgen deprivation therapy (ADT). ADT causes prostate cancers to shrink in volume, or regress, by inducing epithelial tumor cell apoptosis. In normal, non-neoplastic murine prostate, androgen deprivation via castration induces prostate gland regression that is dependent on TNF signaling. In addition to this direct mechanism of action, castration has also been implicated in an indirect mechanism of prostate epithelial cell death, which has been described as vascular regression. The initiating event is endothelial cell apoptosis and/or increased vascular permeability. This subsequently leads to reduced blood flow and perfusion, and then hypoxia, which may enhance epithelial cell apoptosis. Castration-induced vascular regression has been observed in both normal and neoplastic prostates. We used photoacoustic, power Doppler, and contrast-enhanced ultrasound imaging, and CD31 immunohistochemical staining of the microvasculature to assess vascular integrity in the period immediately following castration, enabling us to test the role of TNF signaling in vascular regression. In two mouse models of androgen-responsive prostate cancer, TNF signaling blockade using a soluble TNFR2 ligand trap reversed the functional aspects of vascular regression as well as structural changes in the microvasculature, including reduced vessel wall thickness, cross-sectional area, and vessel perimeter length. These results demonstrate that TNF signaling is required for vascular regression, most likely by inducing endothelial cell apoptosis and increasing vessel permeability. Since TNF is also the critical death receptor ligand for prostate epithelial cells, we propose that TNF is a multi-purpose, comprehensive signal within the prostate cancer microenvironment that mediates prostate cancer regression following androgen deprivation