Single nucleotide polymorphism array analysis of uveal melanomas reveals that amplification of CNKSR3 is correlated with improved patient survival.

Metastatic death from uveal melanoma occurs almost exclusively with tumors showing monosomy of chromosome 3. However, approximately 5% of patients with a disomy 3 uveal melanoma develop metastases, and a further 5% of monosomy 3 uveal melanoma patients exhibit disease-free survival for >5 years. In the present study, whole-genome microarrays were used to interrogate four clinically well-defined subgroups of uveal melanoma: i) disomy 3 uveal melanoma with long-term survival; ii) metastasizing monosomy 3 uveal melanoma; iii) metastasizing disomy 3 uveal melanoma; and iv) monosomy 3 uveal melanoma with long-term survival. Cox regression and Kaplan-Meier survival analysis identified that amplification of the CNKSR3 gene (log-rank, P = 0.022) with an associated increase in its protein expression (log-rank, P = 0.011) correlated with longer patient survival. Although little is known about CNKSR3, the correlation of protein expression with increased survival suggests a biological function in uveal melanoma, possibly working to limit metastatic progression of monosomy 3 uveal melanoma cells.

Morphology and antigen expression profile of pulmonary neuroendocrine cells in reactive proliferations and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH).

AIMS: To compare the morphology and antigenic profile of pulmonary neuroendocrine cells (PNECs) proliferating as a reaction to pulmonary injury with those proliferating in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) in which carcinoids develop. METHODS AND RESULTS: The morphology and expression of a range of antigens including markers of epithelial differentiation [cytokeratins, thyroid transcription factor (TTF)-1], neuroendocrine antigens [neural cell adhesion molecule (NCAM), chromogranin, protein gene product (PGP) 9.5, neurone-specific enolase (NSE), synaptophysin], peptide products [gastrin-releasing peptide (GRP), calcitonin, calcitonin gene-related peptide (CGRP)] and inactivator [common acute lymphoblastic leukaemia antigen (CALLA)] and antigens involved in cell proliferation and death (p53, p16, p27, Rb, Bcl-2, c-kit, Ki67) were studied in four cases of reactive PNEC proliferation and seven cases of DIPNECH. Proliferation was more florid in DIPNECH. There was no major shift in antigen expression with proliferation in either group apart from CALLA, which was expressed only by proliferating cells and not by solitary PNECs. There were differences between the groups in expression of p53, p16 and Ki67, which were seen more consistently and earlier in proliferation in DIPNECH. CONCLUSIONS: These data suggest that there are early and fundamental differences in cell kinetics between the reactive PNEC proliferation that occurs in response to pulmonary injury and that seen in the pre-neoplastic condition of DIPNECH.

Characterization of epithelial cell shedding from human small intestine.

Intestinal epithelial cells migrate from the base of the crypt to the villi where they are shed. However, little is known about the cell shedding process. We have studied the role of apoptosis and wound healing mechanisms in cell shedding from human small intestinal epithelium. A method preparing paraffin sections of human small intestine that preserves cell shedding was developed. A total of 14 417 villus sections were studied. The relationship of cell shedding to leukocytes (CD45), macrophages (CD68) and blood vessels (CD34) were studied by immunohistochemistry. Apoptotic cells were identified using the M30 antibody against cleaved cytokeratin 18 and an antibody against cleaved caspase-3. Potential wound healing mechanisms were studied using antibodies against Zona Occludens-1 (ZO-1) and phosphorylated myosin light chains (MLCs). We found that 5.3% of villus sections contained a shedding cell. An eosin-positive gap was often seen within the epithelial monolayer beneath shedding cells. Shedding was not associated with leukocytes, macrophages or blood vessels. Cells always underwent apoptosis during ejection from the monolayer. Apoptotic bodies were never seen in the monolayer but morphologically normal cells that were positive for M30 or cleaved caspase-3 were often seen. ZO-1 protein was usually (41/42) localized to the apical pole of cells neighboring a shedding event. Phosphorylated MLCs could be identified in 50% of shedding events. In conclusion, cell shedding is associated with apoptosis though it remains unclear whether apoptosis initiates shedding. It is also associated with phosphorylation of MLCs; a process associated previously with wound healing.

Transcription factor E2F3 overexpressed in prostate cancer independently predicts clinical outcome.

E2F transcription factors, including E2F3, directly modulate expression of EZH2. Recently, overexpression of the EZH2 gene has been implicated in the development of human prostate cancer. In tissue microrarray studies we now show that expression of high levels of nuclear E2F3 occurs in a high proportion (98/147, 67%) of human prostate cancers, but is a rare event in non-neoplastic prostatic epithelium suggesting a role for E2F3 overexpression in prostate carcinogenesis. Patients with prostate cancer exhibiting immunohistochemically detectable nuclear E2F3 expression have poorer overall survival (P=0.0022) and cause-specific survival (P=0.0047) than patients without detectable E2F3 expression. When patients are stratified according to the maximum percentage of E2F3-positive nuclei identified within their prostate cancers (up to 20, 21-40%, etc.), there is an increasingly significant association between E2F3 staining and risk of death both for overall survival (P=0.0014) and for cause-specific survival (P=0.0004). Multivariate analyses select E2F3 expression as an independent factor predicting overall survival (unstratified P=0.0103, stratified P=0.0086) and cause-specific survival (unstratified P=0.0288, stratified P=0.0072). When these results are considered together with published data on EZH2 and on the E2F3 control protein pRB, we conclude that the pRB-E2F3-EZH2 control axis may have a critical role in modulating aggressiveness of individual human prostate cancer.

Amplification and overexpression of E2F3 in human bladder cancer.

We demonstrate that, in human bladder cancer, amplification of the E2F3 gene, located at 6p22, is associated with overexpression of its encoded mRNA transcripts and high levels of expression of E2F3 protein. Immunohistochemical analyses of E2F3 protein levels have established that around one-third (33/101) of primary transitional cell carcinomas of the bladder overexpress nuclear E2F3 protein, with the proportion of tumours containing overexpressed nuclear E2F3 increasing with tumour stage and grade. When considered together with the established role of E2F3 in cell cycle progression, these results suggest that the E2F3 gene represents a candidate bladder cancer oncogene that is activated by DNA amplification and overexpression.

Stimulation of MMP-7 (matrilysin) by Helicobacter pylori in human gastric epithelial cells: role in epithelial cell migration.

Epithelial cell responses to bacterial infection include induction of matrix metalloproteinase 7 (MMP-7). Here, we identify increased MMP-7 expression in the gastric epithelium in response to the oncogenic bacterium Helicobacter pylori, and report on the mechanisms and consequences for gastric epithelial cell migration. In patients infected with H. pylori, there was increased MMP-7 in gastric biopsies detected by western blot. MMP-7 was localized to the advancing edge of migrating gastric epithelial cell colonies, including lamellipodia. Rates of spreading of gastric gland cells were higher in H. pylori-infected cultures compared with control, and this was inhibited by antisense oligonucleotides to MMP-7. Complementary data were obtained in a gastric cancer cell line (AGS cells). In the latter, H. pylori induced expression of an MMP-7-luciferase promoter/reporter vector through mechanisms that involved activation of Rho and Rac. RhoA acted through activation of both NF-kappaB and AP-1, whereas Rac activated NF-kappaB but not AP-1. MMP-7 is commonly upregulated in gastric cancer; since H. pylori is a recognized gastric carcinogen, the data suggest a new mechanism by which the bacterium might predispose towards gastric neoplasia.

Evaluation of HER-2/neu immunohistochemical assay sensitivity and scoring on formalin-fixed and paraffin-processed cell lines and breast tumors: a comparative study involving results from laboratories in 21 countries.

Variation in assay sensitivity was studied in more than 90 laboratories that assayed 4formalin-fixed, paraffin-processed breast and ovarian carcinoma cell lines with graded levels of HER-2/neu protein overexpression and known levels of HER-2/neu gene amplification, in addition to breast carcinomas fixed and processed in the laboratories. Main methods were the HercepTest (DAKO, Ely, England) and individualized protocols using a polyclonal antibody and the CB11 clone. While the proportion of laboratories achieving appropriate results with the HercepTest was significantly higher than for participants using other assays, laboratories using other assays showed significant improvement in the second assessment run. The level of agreement in evaluations by 26 laboratories using the HercepTest was excellent on cell lines and tumors and was significantly greater than that achieved by the remaining 41 laboratories using other immunohistochemical methods. While laboratories using the DAKO HercepTest had the highest level of reproducibility in assay sensitivity and evaluation, the significant improvement in results by laboratories using other antibodies in the second assessment run suggests that stringent quality control and an ongoing quality assurance program using a standard reference material have the potential to improve the reliability of immunohistochemical assays for HER-2/neu, regardless of the antibody used.

A formalin-fixed, paraffin-processed cell line standard for quality control of immunohistochemical assay of HER-2/neu expression in breast cancer.

To ensure the accuracy and reproducibility of immunohistochemical assays for determining HER-2/neu status of patients with breast cancer, a reliable standard for monitoring assay sensitivity is necessary. We optimally fixed and paraffin processed human ovarian and breast carcinoma cell lines SKOV-3, MDA-MB-453, BT-20, and MCF-7 in quantities sufficient to meet the needs of a laboratory for the foreseeable future. The material was tested, alongside HercepTest kit cell lines (DAKO, Carpinteria, CA), by 7 breast cancer centers in the United Kingdom and France with different immunohistochemical assays and markers. The cell lines also were analyzed by fluorescence in situ hybridization (FISH) by 2 centers using HER-2/neu kits. FISH produced 100% agreement between the 2 centers: SKOV-3 and MDA-MB-453 showed HER-2/neu amplification and BT-20 and MCF-7 did not. Immunohistochemical analysis and a common evaluation method produced 100% agreement that SKOV-3 and MCF-7 showed 3+ and zero HER-2/neu overexpression, respectively. For MDA-MB-453, there was 71% (5/7) concordance of 2+ immunohistochemical staining and 86% (6/7) concordance of zero or 1 + staining for BT-20. The cell lines provide a valuable standard for gauging HER-2/neu assay sensitivity irrespective of the antibody, antigen retrieval system, detection system, or method of evaluation used.