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Proliferation Status (proliferation + status)
Selected AbstractsIncreased Expression of Cyclin D1, Cyclin E and p21Cip1 Associated with Decreased Expression of p27Kip1 in Chemically Induced Rat Mammary CarcinogenesisCANCER SCIENCE, Issue 12 2000Tae Jung Jang We induced rat mammary tumors in 7-week-old female Sprague-Dawley rats by intragastric administration of 7,12-dimethylbenz(a)anthracene (DMBA), and analyzed by immunohistochemistry the expression of cyclin D1, cyclin E, p21Cip1, and p27Kip1 in carcinomas, atypical tumors, and benign tumors as well as normal mammary glands from the control group. Proliferation status was assessed by immunohistochemistry using bromodeoxyuridine (BrdU). A sequential increase in cyclin D1-, cyclin E-, and p21Cip1 -positive epithelial cells was observed from normal mammary glands, to atypical tumors, to carcinomas. In contrast, carcinomas showed a significantly lower number of epithelial cells immunoreactive to p27Kip1 when compared with atypical tumors, benign tumors and normal mammary glands. The immunoreactivities of BrdU, cyclin D1, cyclin E, and p21Cip1 were positively correlated, whereas that of p27Kip1 appeared inversely correlated to those of the others. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analysis were also performed to determine the mRNA and protein levels of cyclins and cyclin-dependent kinase inhibitors in tumors and normal mammary glands. The protein levels for cyclin D1, cyclin E and p21Cip1 in carcinomas and atypical tumors were significantly higher than those in benign tumors, while normal mammary glands showed negligible expression. On RT-PCR, tumors showed higher mRNA levels of cyclin D1 and cyclin E than those of normal mammary glands. Our results suggest that rat mammary carcinogenesis involves increased expression of cyclin D1, cyclin E, and p21Cip1, associated with decreased expression of p27Kip1 [source] COX-2 mRNA expression in esophageal squamous cell carcinoma (ESCC) and effect by NSAIDDISEASES OF THE ESOPHAGUS, Issue 1 2008X. Liu SUMMARY., To investigate cyclooxygenase-2 (COX-2) mRNA expression in human esophageal squamous cell carcinoma and the effect of a non-steroidal anti-inflammatory drug (NSAID) on it, in order to explore the mechanism of COX-2 in esophageal squamous cell carcinoma (ESCC) carcinogenesis and the ability of NSAID to prevent or treat ESCC. Frozen specimens of human ESCC and adjacent normal esophageal squamous epithelium pairs (n = 22) were examined for COX-2 mRNA expression by reverse-transcription polymerase chain reaction (RT-PCR). After incubation with aspirin (a non-selective COX inhibitor) or Nimesulide (a selective COX-2 inhibitor), the proliferation status of two human esophageal squamous cancer cell lines, EC-9706 and EC-109, was quantified by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide assay. The expression of COX-2 mRNA in these cells was detected by RT-PCR. COX-2 mRNA was expressed in 12 of 22 (54.5%) ESCC tissue samples, but it was undetectable in all the specimens of adjacent normal esophageal squamous epithelium COX-2 mRNA expression. Both aspirin (5,20 mmol/L) and Nimesulide (0.1,0.8 mmol/L) inhibited EC-9706 cell line proliferation and suppressed its COX-2 mRNA expression dose-dependently. However, only aspirin (5,20 mmol/L) could inhibit proliferation in the EC-109 cell line and suppress COX-2 mRNA expression. Nimesulide (0.1,0.8 mmol/L) could neither inhibit EC-109 cell growth nor suppress COX-2 mRNA expression. COX-2 mRNA expression is a frequent phenomenon in human ESCC tissue samples and plays an important role in the carcinogenesis of ESCC. NSAID may be useful in the chemoprevention and therapy of human ESCC and its effects are likely to be mediated by modulating COX-2 activity. [source] c - fos and estrogen receptor gene expression pattern in the rat uterine epithelium during the estrous cycleMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2003C. Adriana Mendoza-Rodríguez Abstract Different studies in ovariectomized estrogen treated animals support the idea that c - fos plays a role in the proliferation of uterine epithelial cells. However, these studies invite us to reassess the role played by c - fos in epithelial cell types of the endometrium during the estrous cycle. The present study was undertaken to determine the c - fos and estrogen receptor (ER) gene expression pattern in the rat uterine epithelium during the estrous cycle in which natural and cyclic changes of steroid hormones occur, and correlate these changes with the proliferation status of this cellular types. Proliferation was assessed during the estrous cycle using bromodeoxyuridine incorporation to DNA. ER, and , proteins were assessed by immunohistochemistry. The regulation of c - fos gene expression in the uterus of intact animals during the estrous cycle was evaluated using both in situ hybridization and immunohistochemistry. Estradiol (E2) and progesterone (P4) plasma levels were assessed by radioimmunoassay. The results indicated that luminal (LE) and glandular epithelia (GE) presented maximal proliferation during the metestrus (M) and the diestrus (D) days. However, during the proestrus (P) day only LE presented proliferation, and during the estrus (E) day only the stromal cells proliferated. A marked immunostaining for ER, was detected in both LE and GE cells during the early phases of the cycle but diminished on the P and the E day. In contrast, ER, was undetectable in both epithelia during all stages of the cycle. The highest c - fos mRNA level was detected in both epithelia on the M day, followed by a significant reduction during the other days of the cycle. The highest protein content was observed on the M and D days, and the minimal value was detected on the E day. The c-Fos protein level in LE was increased during M and D days, presenting a high correlation with the cellular proliferation pattern of this cell type. In conclusion, the overall results indicate that c-Fos protein presented a good correlation with uterine epithelial cell proliferation of LE. In the case of GE, the same tendency was observed, although no significant correlation was found. Both in LE and GE, c - fos mRNA did not strictly correlate with its protein levels. c - fos seems to have a postranscriptional regulation in uterine epithelial cells during the rat's estrous cycle. Mol. Reprod. Dev. 64: 379,388, 2003. © 2003 Wiley-Liss, Inc. [source] Characterization of endoglin and Ki-67 expression in endothelial cells from benign and malignant lesions of the uterine cervixPATHOLOGY INTERNATIONAL, Issue 10 2009Anca M. Cimpean Activation of endothelial cells is often associated with the cellular proliferation in vitro. CD105 is a more specific marker of activated endothelial cells from tumor vessels and Ki-67 is used to assess the proliferation status of both tumor and endothelial cells. The aim of the present study was to evaluate the status of endothelial cells using CD105 and Ki-67 immunohistochemistry in benign and malignant lesions of the uterine cervix. Double stain for CD105/Ki-67 in benign and malignant lesions of the uterine cervix showed that these two markers had divergent expression on endothelial cells from associated tumor blood vessels dependent on lesion type and proliferation status of tumor cells. Absence of CD105/Ki-67 coexpression in endothelial cells was correlated with histopathology of the uterine cervix lesions and tumor proliferative status. The present findings suggest that CD105 expression is an early event, specific for premalignant lesions of the uterine cervix, while endothelial proliferation assessed on Ki-67 combined with the lack of CD105 expression is often associated with invasive cervical carcinoma. [source] The hTERT-protein and Ki-67 labelling index in recurrent and non-recurrent meningiomasCELL PROLIFERATION, Issue 1 2005L. Maes However, a number of these tumours recur even after total resection. The aim of this study is to evaluate the prognostic significance for recurrence of the human telomerase catalytic subunit (hTERT) in the cells of meningiomas. The expression of hTERT-protein can be evaluated by immunohistochemical staining using a monoclonal antibody against hTERT (clone 44F42, NCL-L-hTERT). The interdependence between tumour recurrence and cell proliferation in this study is analysed by Ki-67 immunoreactivity (clone MIB-1). Archival material from 29 non-recurrent and 32 recurrent tumours has been evaluated, including specimens from World Health Organization (WHO) stages I (n = 73), II (n = 2) and III (n = 12). Although the tumours were categorized as benign meningiomas following the WHO classification, recurrence in 22 of 50 cases did not correlate with the tumour stage. For hTERT staining, the following results were found for nucleolar and total nuclear staining, respectively: non-recurrent meningiomas, 2.9% (± 7.7) and 3.0% (± 8.0); recurrent meningiomas at first resection, 16.8% (± 19.7) and 31.6% (± 30.2). Concerning the Ki-67 labelling index (LI): for the group of non-recurrent meningiomas, results were 2.1% (± 1.7) and for the recurrent group at first resection, 1.7% (± 2.0). A significant difference was seen for the hTERT staining (P < 0.001) between the non-recurrent and recurrent meningiomas, whereas no statistical significance was found for Ki-67. In conclusion hTERT-positive meningiomas had a high incidence for recurrence. Ki-67 was a good marker of cell proliferation status of the tumours, but did not correlate with recurrence; thus, hTERT alone seemed to be a potential predictor for recurrence. [source] 3134: Identification of potential human corneal endothelial stem-like cell nichesACTA OPHTHALMOLOGICA, Issue 2010G THURET Purpose to study the localization of potential stem-(like) cells in human adult corneal endothelium Methods Fresh (6-12h post mortem) and organ cultured (OC) corneas were studied after flat mount. The whole endothelium and posterior limbus (PL) was observed after triple staining with Trypan blue, Alizarin red and Hoechst 33342, in order to determine cells shape, localization and viability. The level of endothelial cell (EC) differenciation was determined after immunostaining (fluorescence) for ZO-1, Na+/K+ ATPase and COX IV; the cell proliferation status was assessed using Ki67; four markers for stem cells were used: Oct-4, BCRP, Nestin and Telomerase; ability for cell migration was evaluated from Myosin IIA expression Results In several corneas, the nuclei of peripheral EC were centripetally aligned suggesting continuous slow central migration. Numerous small cells with a reduced expression of differenciation markers were accumulated near peripheral Hassall Henle bodies. In these potential niches, cells were distributed in 3-5 layers. A high expression of Myosin II was found in peripheral cells. Ki67+ cells were found in PL and peripheral EC only after OC. None of the 4 stem cell markers was found in EC, and their expression in PL was poorly reliable because of high background noise. Numerous trypan blue positive cells were located at the PL and in the extreme periphery of endothelium Conclusion several strong arguments suggest the location of corneal endothelial stem-like cell niches in endothelial periphery or in the PL, and the capacity of EC to migrate from these niches toward the centre. Trypan blue staining pattern suggests that they could rapidly die in ex vivo corneas, and be therefore hard to indentify [source] | |||||||||||||