Proliferation Of Surface Epithelial Cells Research Articles

Abstract 1006: Soluble epoxide hydrolase gene deficiency attenuates colitis-induced carcinogenesis in IL-10 knockout mice

Abstract Soluble epoxide hydrolase (sEH) can quickly inactivate epoxyeicosatrienoic acids (EETs) anti-inflammatory function via converting it to dihydroxyeicosatrienoic acid (DHETs). Inhibition of sEH has shown effects against inflammation. But little is studied about the effect of sEH on colitis-induced carcinogenesis. In this study, we determined the role of sEH gene deficiency in suppressing the development of colitis-induced tumor using chronic colitis mouse model in IL-10 knockout mice combined with sEH gene deficiency. Tumor formation in the bowel was examined at age of 25 weeks for male mice and 35 weeks for female mice. Our results showed that sEH (-/-)/IL-10 (-/-) mice exhibited a significant decrease of tumor multiplicity (2 tumor/mouse vs. 1 tumor/mouse) and tumor size (344.55±71.73 vs. 126.94±23.18 mm3, p=0.028) as compared to IL-10(-/-) mice. But no difference was observed for tumor incidence. Colitis-induced dysplasia was further identified by Ki67-labeled luminal surface epithelial cell proliferation combined with morphologic features and revealed that the number of dysplasia was significantly decreased in sEH (-/-)/IL-10 (-/-) mice. Histopathological analysis of inflammatory activity in the bowel showed the significantly lower inflammation scores, including inflammation-involved area (1.4±0.18 vs. 0.70±0.16, P=0.007), ulcer (2.15±0.18 vs. 1.55±0.35, P=0.032), and myeloperoxidase-labeled inflammatory cell infiltrates in sEH (-/-)/ IL-10(-/-) mice compared to IL-10(-/-) mice. qPCR and western blotting assays showed a downregulation of inflammatory cytokines and NF-kB signals. Analysis of eicsanoid acid metabolic profile confirmed sEH functional deficiency and showed a significant increase in the ratios of EETs/DHET and EpOME/DiOME in sEH (-/-)/IL-10 (-/-) mice compared to IL-10(-/-) mice. The results indicate that sEH gene plays an important role in the development of chronic colitis-induced carcinoma and could serve as a crucial target of cancer chemoprevention. (Supported by NIH R01 grant CA137467) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1006. doi:1538-7445.AM2012-1006

Whole ovary immunohistochemistry for monitoring cell proliferation and ovulatory wound repair in the mouse

BackgroundOvarian surface epithelial cells are thought to be a precursor cell type for ovarian carcinoma. It has been proposed that an increased rate of ovarian surface epithelial cell proliferation during ovulatory wound repair contributes to the accumulation of genetic changes and cell transformation. The proliferation of ovarian surface epithelial cells during ovulatory wound repair has been studied primarily using immunohistochemical staining of paraffin-embedded ovary sections. However, such analyses require complex reconstruction from serially-cut ovary sections for the visualization and quantification of the cells on the ovarian surface. In order to directly visualize the proliferation and organization of the ovarian surface epithelial cells, we developed a technique for immunohistochemical staining of whole mouse ovaries. Using this method, we analyzed cell proliferation and morphologic changes in mouse ovarian surface epithelial cells during follicle growth and ovulatory wound repair.MethodsThree-week old FVB/N female mice were superovulated by sequential administration of pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Ten hours after hCG administration, mice were given 5-bromo-2-deoxyuridine (BrdU) and euthanized two hours after BrdU administration for ovary isolation. The levels of incorporated BrdU in the ovarian surface epithelial cells were measured by staining paraffin-embedded ovary sections and whole ovaries with the BrdU antibody. Re-epithelialization of the ovarian surface after ovulatory rupture was visualized by immunohistochemical staining with E-cadherin and Keratin 8 in paraffin-embedded ovary sections and whole ovaries.ResultsWe determined that active proliferation of ovarian epithelial surface cells primarily occurs during antral follicle formation and, to a lesser extent, in response to an ovulatory wound. We also demonstrated that ovarian surface epithelial cells exhibit a circular organization around the wound siteConclusionWhole ovary immunohistochemistry enables efficient and comprehensive three-dimensional visualization of ovarian surface epithelial cells without the need for laborious reconstruction from immunohistochemically-stained serial ovary sections.

Papilloma and papillary carcinoma

Papillomas and papillary carcinomas differ in their 3 fundamental characteristics: the geometric properties of their fronds, the amount of their stroma, and the characteristics of their epithelium. Fibrosis at the edge of papillomas often entraps glands and creates the spurious impression of invasion. The proliferation of surface epithelial cells of papillomas does not give rise to unexpected diagnostic difficulties, but glandular proliferation within the stalks of papillomas often simulates the appearance of cribriform ductal carcinoma in situ. Needle biopsies of papillomas can deposit clusters of benign cells in a distribution that resembles an invasive carcinoma. Although papillomas overrun by ductal carcinoma in situ exhibit a papillary architecture, other features differentiate them from conventional papillary carcinomas. The presence of basal carcinoma cells with clear cytoplasm ("dimorphic" cells) and the formation of short stubby fronds sometimes cause pathologists to mistake papillary carcinomas for papillomas, and the bland cytologic characteristics of solid papillary carcinomas can lead to the same error. Conventional papillary carcinomas typically invade in a blunt manner. This phenomenon complicates the recognition of invasion by many papillary carcinomas and has given rise to controversy about the nature of the lesion classically known as "intracystic papillary carcinoma."

Hepatocyte growth factor induces rat ovarian surface epithelial cell mitosis or apoptosis depending on the presence or absence of an extracellular matrix.

The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To assess the effects of hCG and HGF on ovarian surface epithelial cell mitosis, ROSE-179 cells were cultured for 24 h in serum-supplemented medium on either glass or the synthetic fibronectin-like extracellular matrix protein, pronectin (RGD). The cells were then cultured for 24 h in serum-free medium in the presence or absence of hCG or HGF. The numbers of cells at 2, 24, and 48 h of culture were determined. The percentage of apoptotic cells was assessed by in situ DNA staining at 48 h of culture. In the serum-supplemented medium in the presence or absence of RGD, the number of ROSE-179 cells doubled. In serum-free medium, cell proliferation was reduced, and the percentage of apoptotic nuclei ranged between 10-15% regardless of the substrate. Neither mitosis nor apoptosis was influenced by hCG in the presence or absence of RGD. For ROSE-179 cells cultured in serum-free medium on RGD, HGF induced mitosis, resulting in a 2.8 +/- 0.2-fold increase in cell number compared with the 24 h control values. On a glass substrate in serum-free medium, HGF did not induce mitosis, but increased the percentage of apoptotic nuclei. Time-lapse photographic analysis revealed that on RGD, cells undergoing HGF-induced mitosis showed a transient reduction in cell contact. On glass, HGF caused many cells to completely lose contact and separate from each other. Collectively, these data suggest that in vivo gonadotropins stimulate HGF expression and ovarian surface epithelial cell proliferation. Based on in vitro studies, it is likely that the mitogenic action of hCG is mediated by HGF. However, HGF only induces mitosis in the presence of an extracellular matrix.

Histochemical analysis of hyperplastic stomach of TGF-alpha transgenic mice.

Hypertrophic gastric mucosa in transgenic mice overexpressing transforming growth factor (TGF)-alpha showed mucosal cellular hyperplasia with dysplasia, suppression of gastric acid secretion, and chief and parietal cell depletion. In order to clarify the effects of TGF-alpha on the gastric mucosa, we analyzed the stomach of TGF-alpha transgenic mice by mucin histochemical staining and immunohistochemical analysis of TGF-alpha. In transgenic mice, especially those older than 3 months, the fundic gland was notably atrophic but the total mucosa was thickened. The mucous neck cells were hypersecretory and associated with abnormal sulfation. Mucosal hyperplasia was caused by proliferation of surface epithelial cells, associated with formation of intracytoplasmic lumina. The hyperplastic foveolar cells revealed production of a high amount of sialomucin. In addition, the involved stomach regionally revealed collagenous fibrosis in the submucosal layer. The wide distribution of TGF-alpha in the hyperplastic foveolar cells was in sharp contrast to negative expression in the foveolar cells in the control mice. These findings demonstrated the various regulatory functions of TGF-alpha in mucin production, fibrogenesis, and neck cell proliferation in the stomach.

Molecular approaches to prevention and detection of epithelial ovarian cancer.

More than 90% of epithelial ovarian cancers arise from single cells. Malignant transformation can be associated with a number of molecular alterations including upregulation of tyrosine kinases and phosphatases, physiologic activation o ras, mutation of p53, amplification of myc, and increased activity of matrix metalloproteinases 2 and 9. Proliferation of transformed epithelial cells can be enhanced through the persistence of autocrine growth stimulation by TGF-alpha, loss of autocrine growth inhibition by TGF-beta, as well as paracrine growth stimulation by macrophage derived cytokines and OCAF, a novel lyso-phospholipid. Ascites tumor cells retain responsiveness to growth inhibition by TGF-beta which induces apoptosis in malignant ovarian epithelial cells, but not in normal ovarian surface epithelium. Proliferation of surface epithelial cells following ovulation may contribute to the pathogenesis of ovarian cancer. Use of oral contraceptives that suppress ovulation has been associated with reduced risk of ovarian cancer in later life. Retinoids also deserve further evaluation for chemoprevention. Treatment with fenretinide was associated with decreased incidence of ovarian cancer. Additive or synergistic inhibition of ovarian tumor cell proliferation has been observed with TGF-beta in combination with all-trans-retinoic acid. Early detection of ovarian cancer could improve survival. Transvaginal sonography (TVS) and serum markers such as CA-125 have been evaluated in multiple clinical trials. The former lacks adequate specificity, whereas the latter is not sufficiently sensitive. Use of multiple serum markers can improve sensitivity. A combination of CA-125, M-CSF and OVX-1 has detected > 95% of Stage I ovarian cancers. If similar results are obtained with different data sets, multiple serum markers could be used to trigger the performance of TVS, providing a potentially cost effective screening strategy. Prospective trials will be required to demonstrate that screening for early stage ovarian actually impacts on survival.

Regional increases in rat nasal epithelial cell proliferation following acute and subchronic inhalation of formaldehyde

Short-term studies (9 days) in the rat have demonstrated that formaldehyde-induced nasal epithelial lesions are associated with increases in surface epithelial cell proliferation rates. The present studies were designed, in part, to investigate cell proliferation rates in the nasal epithelium of rats exposed to formaldehyde for a longer duration in order to determine if correlations exist between (1) the concentration-response in cell proliferation rate with the previously published formaldehyde bioassay tumor response; (2) sites of increased cell proliferation and the regions of the nasal passages that exhibit formaldehyde-induced cytotoxicity; and (3) sites of increased cell proliferation and the regions of the rat nasal passages previously determined to be most susceptible to neoplasia (i.e., the lateral meatus and nasal septum of the anterior nasal passages). Another important endpoint of this study was to provide data for a comparison of formaldehyde-induced responses in rats with previous findings in rhesus monkeys. Fischer-344 rats were exposed to 0, 0.7, 2, 6, 10, or 15 ppm formaldehyde for up to 6 weeks and pulse labeled with tritiated thymidine prior to each scheduled termination. Exposure to formaldehyde at 6 ppm or higher induced site-specific lesions in the nasal respiratory epithelium and was associated with increases in cell proliferation rate which remained statistically elevated throughout the 6 weeks. While a direct correlation between sites susceptible to formaldehyde-induced nasal cancer and increased cell proliferation was not evident, results from the present studies did demonstrate a clear correlation between sites of cellular injury and increases in cell proliferation and a concentration-dependent response which correlated with the previously published formaldehyde bioassay tumor response. Furthermore, this work demonstrated that form-aldehyde-induced responses in rats exposed to 6 ppm were morphologically similar to those reported in the rhesus monkey; however, the distribution of lesions between the two species differed significantly.