Dynamic expression of Dab2 in the mouse embryonic central nervous system

<p>Abstract</p> <p>Background</p> <p>Dab2, one of two mammalian orthologs of <it>Drosophila Disabled</it>, has been shown to be involved in cell positioning and formation of visceral endoderm during mouse embryogenesis, but its role in neuronal development is not yet fully understood. In this report, we have examined the localization of the Dab2 protein in the mouse embryonic central nervous system (CNS) at different developmental stages.</p> <p>Results</p> <p>Dab2 protein was transiently expressed in rhombomeres 5 and 6 of the developing hindbrain between E8.5 and E11.5, and in the floor plate of the neural tube from E9.5 to E12.5, following which it was no longer detectable within these regions. Dab2 protein was also identified within circumventricular organs including the choroid plexus, subcommissural organ and pineal gland during their early development. While Dab2 was still strongly expressed in the adult choroid plexus, immunoreactivity within the subcommissural organ and pineal gland was lost after birth. In addition, Dab2 was transiently expressed within a subpopulation of Iba1-positive mononuclear phagocytes (including presumed microglial progenitors) within the neural tube from E10.0 and was lost by E14.5. Dab2 was separately localized to Iba1 positive cells from E9.5 and subsequently to F4/80 positive cells (mature macrophage/myeloid-derived dendritic cells) positioned outside the neural tube from E12.5 onwards, implicating Dab2 expression in early cells of the mononuclear phagocyte lineage. Dab2 did not co-localize with the pan-neuronal marker PGP9.5 at any developmental stage, suggesting that Dab2 positive cells in the developing CNS are unlikely to be differentiating neurons.</p> <p>Conclusion</p> <p>This is the first study to demonstrate the dynamic spatiotemporal expression of Dab2 protein within the CNS during development.</p

Expression of gonadotropin receptor and growth responses to key reproductive hormones in normal and malignant human ovarian surface epithelial cells

Epidemiological data have implicated reproductive hormones as probable risk factors for ovarian cancer (OCa) development. Although pituitary and sex hormones have been reported to regulate OCa cell growth, no information is available regarding whether and how they influence normal ovarian surface epithelial (OSE) cell proliferation. To fill this data gap, this study has compared cell growth responses to gonadotropins and sex steroids in primary cultures of human OSE (HOSE) cells with those observed in immortalized, nontumorigenic HOSE cells and in OCa cell lines. Both malignant and normal cell lines/cultures responded equally well to the stimulatory actions of luteinizing hormone and follicle-stimulating hormone and to 17beta-estradiol and estrone, although the latter estrogen has a much lower affinity for estrogen receptor than does the former estrogen. In normal HOSE cell cultures/lines, 5alpha-dihydrotestosterone was found to be more effective than testosterone in stimulating cell growth, but in OCa cell lines, 5alpha-dihydrotestosterone and testosterone are equally potent. One OCa cell line, OVCA 433, was found to be nonresponsive to androgen stimulation. In general, primary cultures of normal HOSE cells exhibited the greatest hormone-stimulated growth responses (\u3e10-fold enhancement), followed by immortalized HOSE cell lines (4-5-fold enhancement) and by OCa cell lines (2-4-fold enhancement). Interestingly, progesterone (P4), at low concentrations (10(-11) to 10(-10) M), was stimulatory to HOSE and OCa cell growth, but at high doses (10(-8) to 10(-6) M), P4 exerted marked inhibitory effects. In all cases, cotreatment of a cell culture/line with a hormone and its specific antagonist blocked the effect of the hormone, confirming specificity of the hormonal action. Taken together, these data support the hypothesis that reproductive states associated with rising levels of gonadotropins, estrogen, and/or androgen promote cell proliferation in the normal OSE, which favors neoplastic transformation. Conversely, those states attended by high levels of circulating P4, such as that seen during pregnancy, induce OSE cell loss and offer protection against ovarian carcinogenesis

Identification of a Potential Ovarian Cancer Stem Cell Gene Expression Profile from Advanced Stage Papillary Serous Ovarian Cancer

Identification of gene expression profiles of cancer stem cells may have significant implications in the understanding of tumor biology and for the design of novel treatments targeted toward these cells. Here we report a potential ovarian cancer stem cell gene expression profile from isolated side population of fresh ascites obtained from women with high-grade advanced stage papillary serous ovarian adenocarcinoma. Affymetrix U133 Plus 2.0 microarrays were used to interrogate the differentially expressed genes between side population (SP) and main population (MP), and the results were analyzed by paired T-test using BRB-ArrayTools. We identified 138 up-regulated and 302 down-regulated genes that were differentially expressed between all 10 SP/MP pairs. Microarray data was validated using qRT-PCR and17/19 (89.5%) genes showed robust correlations between microarray and qRT-PCR expression data. The Pathway Studio analysis identified several genes involved in cell survival, differentiation, proliferation, and apoptosis which are unique to SP cells and a mechanism for the activation of Notch signaling is identified. To validate these findings, we have identified and isolated SP cells enriched for cancer stem cells from human ovarian cancer cell lines. The SP populations were having a higher colony forming efficiency in comparison to its MP counterpart and also capable of sustained expansion and differentiation in to SP and MP phenotypes. 50,000 SP cells produced tumor in nude mice whereas the same number of MP cells failed to give any tumor at 8 weeks after injection. The SP cells demonstrated a dose dependent sensitivity to specific γ-secretase inhibitors implicating the role of Notch signaling pathway in SP cell survival. Further the generated SP gene list was found to be enriched in recurrent ovarian cancer tumors

The Role of Exosomal miR-181c-3p Within the Ovarian Tumor Microenvironment

https://openworks.mdanderson.org/sumexp22/1034/thumbnail.jp

Differential hRad17 expression by histologic subtype of ovarian cancer

<p>Abstract</p> <p>Background</p> <p>In the search for unique ovarian cancer biomarkers, ovarian specific cDNA microarray analysis identified hRad17, a cell cycle checkpoint protein, as over-expressed in ovarian cancer. The aim of this study was to validate this expression.</p> <p>Methods</p> <p>Immunohistochemistry was performed on 72 serous, 19 endometrioid, 10 clear cell, and 6 mucinous ovarian cancers, 9 benign ovarian tumors, and 6 normal ovarian tissue sections using an anti-hRad17 antibody. Western blot analysis and quantitative PCR were performed using cell lysates and total RNA prepared from 17 ovarian cancer cell lines and 6 normal ovarian epithelial cell cultures (HOSE).</p> <p>Results</p> <p>Antibody staining confirmed upregulation of hRad17 in 49.5% of ovarian cancer cases. Immunohistochemistry demonstrated that only 42% of serous and 47% of endometrioid subtypes showed overexpression compared to 80% of clear cell and 100% of mucinous cancers. Western blot confirmed overexpression of hRad17 in cancer cell lines compared to HOSE. Quantitative PCR demonstrated an upregulation of hRad17 RNA by 1.5-7 fold. hRad17 RNA expression differed by subtype.</p> <p>Conclusions</p> <p>hRad17 is over-expressed in ovarian cancer. This over-expression varies by subtype suggesting a role in the pathogenesis of these types. Functional studies are needed to determine the potential role of this protein in ovarian cancer.</p

Spatially Resolved Transcriptomics Identified Distinct Tumor-Stroma Crosstalk Networks Associated With Chemoresistance in Ovarian Cancer

https://openworks.mdanderson.org/sumexp21/1135/thumbnail.jp

Etiology and Pathogenesis of Epithelial Ovarian Cancer

Ovarian cancer is complex disease composed of different histological grades and types. However, the underlying molecular mechanisms involved in the development of different phenotypes remain largely unknown. Epidemiological studies identified multiple exogenous and endogenous risk factors for ovarian cancer development. Among them, an inflammatory stromal microenvironment seems to play a critical role in the initiation of the disease. The interaction between such a microenvironment, genetic polymorphisms, and different epithelial components such as endosalpingiosis, endometriosis, and ovarian inclusion cyst in the ovarian cortex may induce different genetic changes identified in the epithelial component of different histological types of ovarian tumors. Genetic studies on different histological grades and types provide insight into the pathogenetic pathways for the development of different disease phenotypes. However, the link between all these genetic changes and the etiological factors remains to be established

Genomic and Expression Analysis of the 12p11-p12 Amplicon Using EST Arrays Identifies Two Novel Amplified and Overexpressed Genes

We performed parallel array comparative genomic hybridization and array expression analysis of the 12p11-p12 amplicon in human testicular seminomas and an ovarian carcinoma cell line using an expressed se- quence tags (ESTs) array spotted with 8254 ESTs. The data were normal- ized using a robust statistical modeling and the significance inferred from the local SD. We identified two ESTs within the chromosomal amplicon that were amplified and overexpressed in >75–100% of analyzed tumors with the 12p11-p12 amplicon. These sequences, belonging to coding re- gions of two novel genes designated here as GCT1 and GCT2, were broadly expressed in a panel of human tissues, including testis and ovary. GCT1 and GCT2 were overexpressed in 92 and 71%, respectively, of a panel of seminomas tested. Combined array comparative genomic hybridization and array expression analysis is a valid approach for gene discovery in large chromosomal amplicons

CAF-derived MFAP5 is a novel transcription regulator for immune checkpoint CD47 in ovarian cancer

https://openworks.mdanderson.org/sumexp23/1115/thumbnail.jp