Does the presence of an epiretinal membrane alter the cleavage plane during internal limiting membrane peeling?

PURPOSE: To determine whether the presence of a clinically and/or microscopically detectable epiretinal membrane (ERM) alters the cleavage plane during internal limiting membrane (ILM) peeling. DESIGN: Retrospective, observational, immunohistochemical study of ILM specimens using archival formalin-fixed, paraffin-embedded tissue. PARTICIPANTS: Fifty-one patients who had had ILM excision. METHODS: Fifty-one ILM specimens peeled during vitrectomy for various etiologies were examined by light microscopy. The removal of ILM was assisted using Trypan blue (n = 30), indocyanine green (n = 7), or brilliant blue G (n = 14). Monoclonal antibodies to glial fibrillary acidic protein and to neurofilament protein were used to detect glial or neuronal cells respectively on the vitreous or retinal surfaces of the ILM. Specimens were divided into 2 groups: ILM peeled for full-thickness macular hole (MH; n = 31) and ILM peeled after removal of clinically detectable ERM (n = 20). MAIN OUTCOME MEASURES: Primary outcome measure was the localization of immunohistochemical markers to neuronal or glial cells on the vitreous or retinal surfaces of ILM. The secondary outcome measure was the correlation of the results of the primary measure with the dyes used to facilitate ILM peeling. RESULTS: Glial and/or neuronal cells were detected on the retinal surface of the ILM in 10 of 31 (32%) of the MH ILM specimens and in 13 of 20 (65%) of the ILM peeled after ERM excision; the difference was significant (P = 0.02). There was no association between the presence of neuronal and glial cells with the type of dye used (P = 0.2). Of the 23 ILM specimens with cells attached to the retinal surface, 21 (91%) were associated with clinical and/or histologic evidence of ERM and 2 (9%) were not. The correlation between the presence of cells on the vitreous and the retinal surfaces of ILM was high (P<0.0001). CONCLUSIONS: The findings suggest that ERM may be associated with sub-ILM changes that alter the plane of separation during ILM peeling. This study does not confirm any influence of dyes on the cleavage plane during surgery.

A comparison of clinicopathological features and molecular markers in british and nigerian women with breast cancer.

BACKGROUND: Some studies have suggested that breast cancer in black women is more aggressive than in white women. This study's aim was to look for evidence of differences in tumour biology between the two cohorts. METHODS: This study compared the stage, grade and pathological expression of five immunohistochemical markers (oestrogen receptor [ER], progesterone receptor [PR], ERBB2, P53 and cyclin D1 [CCND1]) in tumour biopsies from age-matched cohorts of patients from Nigeria and England. Sixty-eight suitable samples from Nigerian (n = 34) and British (n = 34) breast cancer patients were retrieved from histology tissue banks. RESULTS: There were significant differences between the two cohorts in the expression of ER and CCND1; and stark differences in the clinical stage at presentation. But no significant differences were observed for tumour grade. CONCLUSION: There was a significantly, low ER expression in the Nigerian cases which also predicts a poor response to hormonal therapy as well as a poorer prognosis. Differences in clinical stage at presentation will most likely influence prognosis between Nigerian and British women with breast cancer.

Differential expression of cyclin-dependent kinase inhibitors and apoptosis-related proteins in endocervical lesions.

The development of neoplasia is associated with abnormalities of cell cycle control and apoptosis. In this study, a panel of cyclin-dependent kinase inhibitors (CDKIs) and apoptosis-related proteins (p16, p21, p53, Bcl2 and hsp27) was analysed by immunohistochemistry in 91 glandular cervical lesions. A significant increase in p21 and p53 expression occurred from normal cervix (n=11) through endometriosis/tubo-endometrioid metaplasia (TEM) (n=19) and cervical glandular intraepithelial neoplasia (CGIN)/adenocarcinoma in situ (AIS) (n=33) to invasive adenocarcinoma (n=28). p16 showed diffuse strong expression in CGIN/AIS and invasive adenocarcinoma compared with focal expression in some TEM/endometriosis lesions and no expression in normal cervix. Bcl2 was highly expressed in TEM/endometriosis compared with CGIN/AIS and adenocarcinoma. p16 immunostaining discriminated accurately between neoplastic and non-neoplastic cervical lesions, provided that diffuse strong positivity was present. Similarly, diffuse expression of Bcl2 distinguished endometriosis/TEM from CGIN/AIS. These data demonstrate that analysis of CDKIs and apoptosis-related proteins provides useful information in the diagnostic assessment of glandular lesions of the cervix.

The expression of S100A8 in pancreatic cancer-associated monocytes is associated with the Smad4 status of pancreatic cancer cells.

The cross-talk between tumour cells and the surrounding supporting host cells (stroma) is a key regulator of cancer growth and progression. By undertaking 2-DE analysis of laser capture microdissected malignant and stromal components of pancreatic tumours and benign ductal elements, we have identified high levels of S100A8 and S100A9 in tumour-associated stroma but not in benign or malignant epithelia. Immunohistochemical analysis (n = 71 patients) revealed strong expression of both proteins in stromal myeloid cells, subsequently identified as CD14(+)/CD68(- )monocytes/macrophages. Co-immunofluorescence revealed that S100A8 was expressed in a subset of S100A9-positive cells. Correlation of the expression of S100A8 and S100A9 to patient parameters revealed that the microenvironments of tumours which lacked expression of the tumour suppressor protein, Smad4, had significantly reduced numbers of S100A8-immunoreactive (p = 0.023) but not S100A9-immunoreactive (p = 0.21) cells. The ratio of S100A8- to S100A9-positive cells within individual tumours was significantly lower in Smad4-negative tumours than in Smad4-positive tumours (p<0.003). Pancreatitic specimens also contained S100A8- and S100A9-expressing cells, although this was not observed in regions displaying extensive fibrosis. In conclusion, our study provides an extensive analysis of S100A8 and S100A9 in pancreatic disease and highlights a potentially important relationship between pancreatic cancer cells and their surrounding microenvironment.

Proteomic analysis of chronic pancreatitis and pancreatic adenocarcinoma.

BACKGROUND & AIMS: Markers to differentiate among pancreatic adenocarcinoma, chronic pancreatitis, and normal pancreas would be of significant clinical utility. This study was therefore designed to analyze the proteome of such specimens and identify new candidate proteins for differential diagnosis. METHODS: A PowerBlot analysis with more than 900 well-characterized antibodies was performed with tissue specimens from patients with chronic pancreatitis, pancreatic adenocarcinoma, and normal pancreas. Differential expression of selected proteins was confirmed on a larger scale by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry using tissue arrays. RESULTS: A total of 30 and 102 proteins showed significant deregulation between normal pancreas when compared with chronic pancreatitis and pancreatic adenocarcinoma, respectively, and although a substantial proportion were found similarly dysregulated in both chronic pancreatitis and pancreatic adenocarcinoma, several proteins were identified as potential disease-specific markers. CONCLUSIONS: A large number of proteins are differentially expressed in chronic pancreatitis and pancreatic adenocarcinoma compared with normal pancreas. Among these, expression analysis of UHRF1, ATP7A, and aldehyde oxidase 1 in combination could potentially provide a useful additional diagnostic tool for fine-needle aspirated or cytological specimens obtained during endoscopic investigations.

High nuclear S100A6 (Calcyclin) is significantly associated with poor survival in pancreatic cancer patients.

Recent studies have reported elevated levels of S100A6 in pancreatic ductal adenocarcinoma cells. Here, we describe a detailed analysis of S100A6 expression in benign (n = 32), malignant (n = 60), and premalignant pancreatic ductal cells [96 pancreatic intraepithelial neoplasias (PanIN) from 46 patients]. S100A6 staining was more intense in malignant cells than in benign cells (P = 0.0001). In malignant cells, staining was higher in the nucleus than in the cytoplasm (P = 0.003). Univariate analysis revealed a significant decrease in survival time for patients with high levels of nuclear (P = 0.01) but not cytoplasmic (P = 0.20) S100A6. No evidence was found for an association between nuclear S100A6 expression and other variables, including gender, age at surgery, tumor size or grade, nodal metastases, resection margin, vascular invasion, perineural invasion, p53 or Smad4 levels (both linked to survival in previous studies), or the p65 subunit of nuclear factor-kappaB (a potential regulator of S100A6). Although nodal metastases and resection margin involvement were also associated with poor survival (P = 0.06 in both cases), multivariate analysis suggests that nuclear S100A6 is a significant independent indicator of survival (P = 0.003). Whereas PanIN 1a lesions showed a general absence of S100A6 staining, there was a progressive increase in the proportion of positively stained PanINs with increasing PanIN grade. In particular, we observed an increase in the frequency and intensity of nuclear staining. Our results suggest that up-regulation of S100A6 is an early event in pancreatic cancer development and that elevated levels of nuclear S100A6 may affect clinical outcome.

Overexpression of cyclins A and B as markers of neoplastic glandular lesions of the cervix.

INTRODUCTION: Cyclins are a family of regulatory proteins that play a pivotal role in controlling the cell cycle. While there is evidence of their altered expression in cervical squamous lesions, their precise role in glandular neoplasia is yet to be elucidated. OBJECTIVES: To investigate the role of cyclins as markers of early cervical glandular neoplasia by comparing their expression in lesions of different histological type. METHODS: Through a cross-sectional analytical study, paraffin wax sections of normal cervix (n = 11), endometriosis/tubo-endometrioid metaplasia (TEM) (n = 19), cervical glandular intraepithelial neoplasia (CGIN) (n = 33), and invasive adenocarcinoma (n = 28) were studied using monoclonal antibodies for cyclins A, B, D, and E with heat pretreatment for antigen unmasking. A quantitative assessment was employed for the analysis of percentage expression of each marker. Statistical analysis of data was performed using SPSS. RESULTS: A progressive significant increase in cyclin A expression occurred from normal cervix (median: 0, IQ: 0-0), through endometriosis/TEM (median: 1, IQ: 0-15) and CGIN (median: 15, IQ: 0-30) to invasive adenocarcinoma (median: 40, IQ: 21.25-60). Cyclin B exhibited a similar pattern (median: 0, IQ: 0-0, median: 0, IQ: 0-0.5, median: 8, IQ: 0.75-15, and median: 30, IQ: 15-45, respectively). Statistically higher expression of cyclin B was found in CGIN than in TEM/endometriosis (P < 0.001). Invasive adenocarcinomas expressed higher levels of cyclins A and B than CGIN (P < 0.001). There was significantly greater cyclin E expression in TEM/endometriosis than in normal cervix (P = 0.03) with a nonsignificant further increase in CGIN and invasive adenocarcinoma. The expression of cyclin D was not significantly different among all groups. CONCLUSIONS: Our data indicate that up-regulation of cyclin A and B expression occurs in neoplastic lesions of the cervix. Cyclin B expression was significantly more widespread in CGIN lesions than in TEM/endometriosis indicating that further assessment of the value of this marker in the diagnosis of cervical glandular neoplasia is warranted.

Expression of PAX 3 alternatively spliced transcripts and identification of two new isoforms in human tumors of neural crest origin.

The developmental gene PAX 3 is expressed in the early embryo in developing muscle and elements of the nervous system, including the brain. Since no one has investigated the expression of the isoforms of PAX 3 in the neuroectodermal tumors melanoma and small cell lung cancer (SCLC), we have carried out a comprehensive screening for the expression of the isoforms PAX 3a-e using RT-PCR in human melanoma cell lines, primary human ocular and secondary cutaneous melanomas. We have identified 2 new isoforms of PAX 3, g and h, which we have isolated, cloned and sequenced. Sets of primers for each isoform were designed and their specificity was confirmed by sequence analysis of the products. The isoforms PAX 3a-e were detected in all human cutaneous melanoma cell lines (8/8), but only PAX 3c (1/2) and PAX 3d (2/2) in ocular melanoma cell lines. The same PAX 3 isoforms were detected in more than 80% of human cutaneous melanomas: PAX 3a and b (15/17), PAX 3c (14/17), PAX 3d (16/17) and PAX 3e (15/17). In contrast the results for 7 SCLC cell lines were PAX 3a (0/7), PAX 3b (1/7), PAX 3c (3/7), PAX 3d (6/7), PAX 3e (2/7); 8/8 cutaneous melanoma cell lines and 8/8 ocular melanoma tissues, together with 14/17 cutaneous melanoma tissues screened, expressed the new isoform PAX 3g. All 8 cutaneous melanoma cell lines expressed PAX 3h, but it was not detectable in any of the tumor tissues (0/20). Neither of the 2 ocular melanoma cell lines expressed the 2 new isoforms. Comparison of the different amplicon staining intensities on a gel suggests that PAX 3c and PAX 3d are the predominant transcripts expressed, with relatively low expression of PAX 3e and PAX 3h. We propose that these and the 2 new isoforms we have discovered may be important in oncogenesis and differential diagnosis of melanomas or SCLC.

Application of laser capture microdissection combined with two-dimensional electrophoresis for the discovery of differentially regulated proteins in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal of all the common malignancies and markers for early detection or targets for treatment of this disease are urgently required. The disease is characterised by a strong stromal response, with cancer cells usually representing a relatively small proportion of the cells in the tumor mass. We therefore performed laser capture microdissection (LCM) to enrich for both normal and malignant pancreatic ductal epithelial cells. Proteins extracted from these cells were then separated by two-dimensional gel electrophoresis (2-DE). The limited amounts of protein in the LCM procured samples necessitated the detection of 2-DE resolved proteins by silver staining. Consequently, loading equivalent amounts of protein onto gels was essential. However, we found that conventional means of measuring total protein in the samples were not sufficiently accurate. We therefore adopted a strategy in which the samples were first separated by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis, stained with silver stain and subjected to densitometry. Evaluation of the staining intensity was then used to normalise the samples. We found that the protein profiles from undissected normal pancreas and LCM-acquired non-malignant ductal epithelial cells from the same tissue block were different, underpinning the value of LCM in our analysis. The comparisons of protein profiles from nonmalignant and malignant ductal epithelial cells revealed nine protein spots that were consistently differentially regulated. Five of these proteins showed increased expression in tumor cells while four showed diminished expression in these cells. One of the proteins displaying enhanced expression in tumor cells was identified as the calcium-binding protein, S100A6. To determine the incidence of S100A6 overexpression in pancreatic cancer, we carried out immunohistochemical analysis on sections from a pancreas cancer tissue array containing 174 duplicate normal and malignant pancreatic tissue samples, from 46 pancreas cancer patients. Normal pancreatic ductal epithelia were either devoid of detectable S100A6 or showed weak expression only. Moderately or poorly differentiated tumors, by contrast, showed a higher incidence and a higher level of S100A6 expression. These observations indicate that the combination of LCM with 2-DE provides an effective strategy to discover proteins that are differentially expressed in PDAC.

p53 status correlates with the differential expression of the DNA mismatch repair protein MSH2 in non-small cell lung carcinoma.

We examined the p53 status of 108 NSCLCs compared to the expression of MLH1 and MSH2 proteins. p53 overexpression was demonstrated by IHC in 64% of patients examined, whereas p53 mutations were detected in 43%. Twenty-two percent of mutations were located outside of the hot-spot (exons 5-8) area. p53 mutations and overexpression were more frequent in SCCL (57% and 73%, respectively) than in lung adenocarcinomas (22% and 50%, respectively). In NSCLC-carrying wild-type p53, increased expression of MSH2 correlated with p53 overexpression (p = 0.018). In addition, in SCCL, p53 mutations correlated with reduced MSH2 expression (p = 0.019). These data suggest a relationship between p53 and MSH2. While there is evidence for p53 being a transcriptional activator of MSH2, the hypothesis that MSH2 acts as a DNA-damage signaller triggering p53 overexpression needs to be clarified in future studies.