Ann-Christin Buckendahl

Class I Histone Deacetylase Expression Has Independent Prognostic Impact in Human Colorectal Cancer: Specific Role of Class I Histone Deacetylases In vitro and In vivo

Purpose: Recently, several studies reported a strong functional link between histone deacetylases (HDAC) and the development of tumors of the large intestine. However, despite the importance of these molecules, comparably little is known on expression patterns and functions of specific HDAC isoforms in colorectal cancer. Experimental Design: We characterized class I HDAC isoform expression patterns in a cohort of 140 colorectal carcinomas by immunohistochemistry. In addition, effects of HDAC inhibition by valproic acid and suberoylanilide hydroxamic acid, and specific HDAC isoform knockdown by short interfering RNA, were investigated in a cell culture model. Results: We found class I HDACs highly expressed in a subset of colorectal carcinomas with positivity for HDAC1 in 36.4%, HDAC2 in 57.9%, and HDAC3 in 72.9% of cases. Expression was significantly enhanced in strongly proliferating (P = 0.002), dedifferentiated (P = 0.022) tumors. High HDAC expression levels implicated significantly reduced patient survival (P = 0.001), with HDAC2 expression being an independent survival prognosticator (hazard ratio, 2.6; P = 0.03). Short interfering RNA–based inhibition of HDAC1 and HDAC2 but not HDAC3 suppressed growth of colon cancer cells in vitro, although to a lesser extent than chemical HDAC inhibitors did. Conclusions: The strong prognostic impact of HDAC isoforms in colorectal cancer, the interactions of HDACs with tumor cell proliferation and differentiation in vivo, and our finding that HDACs are differentially expressed in colorectal tumors suggest that the evaluation of HDAC expression in clinical trials for HDAC inhibitors might help to identify a patient subgroup who will exceptionally profit from such a treatment.

Expression of the nuclear export protein chromosomal region maintenance/exportin 1/Xpo1 is a prognostic factor in human ovarian cancer.

The human nuclear export protein chromosomal region maintenance/exportin 1/Xpo1 (CRM1) mediates the nuclear export of proteins and messenger RNAs and, thus, is an important regulator of subcellular distribution of key molecules. Whereas cell‐biologic studies have suggested a fundamental role for CRM1 in the regulation of mitosis, the expression of this protein in human tumor tissue has not been investigated to date.

High class I HDAC activity and expression are associated with RelA/p65 activation in pancreatic cancer in vitro and in vivo

BackgroundThe strong association between aberrant HDAC activity and the occurrence of cancer has led to the development of a variety of HDAC inhibitors (HDIs), which emerge as promising new targeted anticancer therapeutics.MethodsDue to the pivotal role of RelA/p65 in the tumorigenesis of pancreatic neoplasia we examined the expression of class I HDACs 1, 2 and 3 in a large cohort of human pancreatic carcinomas and correlated our findings with RelA/p65 expression status. Furthermore, we investigated the impact of the HDIs SAHA and VPA on RelA/p65 activity in pancreatic cancer cell culture models.ResultsClass I HDACs were strongly expressed in a subset of pancreatic adenocarcinomas and high expression was significantly correlated with increased nuclear translocation of RelA/p65 (p = 0.024). The link of HDAC activity and RelA/p65 in this tumor entity was confirmed in vitro, where RelA/p65 nuclear translocation as well as RelA/p65 DNA binding activity could be markedly diminished by HDI treatment.ConclusionThe RelA/p65 inhibitory effects of SAHA and VPA in vitro and the close relationship of class I HDACs and RelA/p65 in vivo suggest that treatment with HDIs could serve as a promising approach to suppress NF-κB activity which in turn may lead to enhanced apoptosis and chemosensitization of pancreatic cancers.

Peroxisome Proliferator-Activated Receptor γ Is Highly Expressed in Pancreatic Cancer and Is Associated With Shorter Overall Survival Times

Purpose: Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor that has been implicated in carcinogenesis and progression of various solid tumors, including pancreatic carcinoma. We aimed to clarify the expression patterns of PPARγ in pancreatic ductal carcinomas and to correlate these to clinicopathologic variables, including patient survival. Experimental Design: Array-based expression profiling of 19 microdissected carcinomas and 14 normal ductal epithelia was conducted. Additionally, Western blots of pancreatic cancer cell lines and paraffinized tissue of 129 pancreatic carcinomas were immunostained for PPARγ. For statistical analysis, Fishers exact test, χ2 test for trends, correlation analysis, Kaplan-Meier analysis, and Coxs regression were applied. Results: Expression profiles showed a strong overexpression of PPARγ mRNA (change fold, 6.9; P = 0.04). Immunohistochemically, PPARγ expression was seen in 71.3% of pancreatic cancer cases. PPARγ expression correlated positively to higher pT stages and higher tumor grade. Survival analysis showed a significant prognostic value for PPARγ, which was found to be independent in the clinically important subgroup of node-negative tumors. Conclusions: PPARγ is commonly up-regulated in pancreatic ductal adenocarcinoma and might be a prognostic marker in this disease. Both findings corroborate the importance of PPARγ in tumor progression of pancreatic cancer.

Expression patterns of polo‐like kinase 1 in human gastric cancer

Polo‐like kinase 1 (PLK1) is centrally involved in the regulation of mitosis in normal and malignant cells. It is known that inhibition of PLK1 expression in vitro and in vivo leads to mitotic arrest, induction of apoptosis and suppression of tumor growth. In the present study, expression of PLK1 was investigated in paraffin tissue of 135 cases of gastric adenocarcinoma and in 46 corresponding lymph node metastases by immunohistochemistry. Expression data were correlated with clinicopathological parameters and patient survival. Seventy‐three (54.1%) of 135 carcinomas showed an overexpression of PLK1 compared to normal gastric mucosa. Overexpression of PLK1 correlated positively with tumor stage, nodal status and diffuse growth pattern. PLK1 expression in the primary tumor did not differ from PLK1 expression in the corresponding lymph node metastases. PLK1 expression was a significant prognostic factor in univariate but not in multivariate survival analysis. As a conclusion, upregulated PLK1 expression in gastric cancer correlates with a malignant tumor phenotype and has impact on patient prognosis. These data underscore the importance of PLK1 in gastric carcinogenesis and present a translational link for functional data into potential clinical use by defining PLK1 as an attractive protein for novel targeted chemotherapeutic approaches in gastric cancer. (Cancer Sci 2006; 97: 271 –276)

Flat epithelial atypia is a common subtype of B3 breast lesions and is associated with noninvasive cancer but not with invasive cancer in final excision histology

The biological behavior and the optimal management of benign breast lesions with uncertain malignant potential, the so-called B3 lesions, found in breast needle core biopsies is still under debate. We addressed this study to compare histologic findings in B3 needle core biopsies with final excision specimens to determine associated rates of malignancy. Consecutive needle core biopsies were performed in a 3-year period (January 1, 2006-December 31, 2008). Biopsies were image-guided (31 by ultrasound, 85 stereotactic vacuum-assisted, 6 unknown) for evaluation of breast abnormalities. We reviewed 122 needle core biopsies with B3 lesions of 91 symptomatic patients and 31 screen-detected women and compared the B3 histologic subtypes with the final excision histology. A total of 1845 needle core biopsies were performed and B3 lesions comprised 6.6% of all B categories. The most common histologic subtype in biopsies was flat epithelia atypia in 35.2%, followed by papillary lesions in 21% and atypical ductal hyperplasia in 20%. Reports on excision specimens were available in 66% (81 patients). Final excision histology was benign in 73 (90.2%) and malignant in 8 (9.8%) patients (2 invasive cancer, 6 ductal carcinoma in situ). Of all B3 subtypes, atypical ductal hyperplasia and flat epithelial atypia were associated with malignancy, whereas only atypical ductal hyperplasia was accompanied by invasive cancer. Of all lesions, flat epithelial atypia was most frequently found in excision specimens (18%). In our study, flat epithelial atypia and atypical ductal hyperplasia are common lesions of the B3 category in needle core biopsies of the breast. Both lesions are associated with malignancy, whereas only atypical ductal hyperplasia was related to invasive cancer. We conclude that an excision biopsy after diagnosis of flat epithelial atypia is recommended depending on clinical and radiologic findings.

Down-regulation of the antigen processing machinery is linked to a loss of inflammatory response in colorectal cancer

Antitumor inflammatory response is known to inhibit tumor growth in colorectal carcinoma. The density and functionality of tumor-infiltrating lymphocytes (TIL) is regulated by the antigen processing machinery through regulator proteins such as transporters associated with antigen processing (TAP) and major histocompatibility complex (MHC) class I antigen. We aimed to investigate the in vivo association of those factors and their impact on prognosis in colorectal cancer. TAP1, TAP2 and MHC class I antigen expression, inflammatory infiltrate and TIL (CD4(+), CD8(+), and CD20(+)) were assessed by immunohistochemistry in 336 sporadic colorectal carcinomas. The factors were correlated with each other and with clinic-pathological parameters and patient outcome. We found TAP1 and TAP2 expression to be significantly associated with MHC class I antigen expression (TAP1: r = 0.363, P < .001; TAP2: r = 0.393, P < .001). Increased density of CD8(+) TIL was predominantly found in TAP1, TAP2 and MHC class I antigen-positive cases. Increased density of CD4(+) TIL was linked with TAP1 and TAP2, but not with MHC class I antigen. High CD4(+) and CD8(+) cell count but not TAP1, TAP2 and MHC class I antigen expression had favorable prognostic impact in colorectal cancer (P = .003 and P = .003, respectively). In conclusion, our data show that the expression of key components of the antigen processing machinery is tightly linked to the density of TIL, which are positive prognostic factors in colorectal cancer in vivo. This implies that modulation of these factors may help to enhance antitumor inflammatory response which in turn may improve patient prognosis.

An intracellular targeted antibody detects EGFR as an independent prognostic factor in ovarian carcinomas

BackgroundIn ovarian cancer, the reported rate of EGFR expression varies between 4-70% depending on assessment method and data on patient outcome are conflicting. Methods: In this study we investigated EGFR expression and its prognostic value in a cohort of 121 invasive ovarian carcinomas, using a novel antibody against the intracellular domain of the receptor. We further evaluated an association between EGFR, the nuclear transporter CRM1 as well as COX-2. Furthermore, we evaluated EGFR expression in ten ovarian cancer cell lines and incubated cancer cells with Leptomycin B, a CRM1 specific inhibitor.ResultsWe observed a membranous and cytoplasmic EGFR expression in 36.4% and 64% of ovarian carcinomas, respectively. Membranous EGFR was an independent prognostic factor for poor overall survival in ovarian cancer patients (HR 2.7, CI 1.1-6.4, p = 0.02) which was also found in the serous subtype (HR 4.6, CI 1.6-13.4, p = 0.004). We further observed a significant association of EGFR with COX-2 and nuclear CRM1 expression (chi-square test for trends, p = 0.006 and p = 0.013, respectively). In addition, combined membranous EGFR/COX-2 expression was significantly related to unfavorable overall survival (HR 7.2, CI 2.3-22.1, p = 0.001).In cell culture, we observed a suppression of EGFR protein levels after exposure to Leptomycin B in OVCAR-3 and SKOV-3 cells.ConclusionsOur results suggest that the EGFR/COX-2/CRM1 interaction might be involved in progression of ovarian cancer and patient prognosis. Hence, it is an interesting anti-cancer target for a combination therapy. Further studies will also be needed to investigate whether EGFR is also predictive for benefit from EGFR targeted therapies.

Cut-resistant protective gloves in pathology—effective and cost-effective

Cutting injuries and needle-stitch injuries constitute a potentially fatal danger to both pathologists and autopsy personnel. We evaluated such injuries in a large German institute of pathology from 2002 to 2007 and analysed the effect of the introduction of cut-resistant gloves on the incidence of these injuries. In the observation period, 64 injuries (48 cutting injuries and 16 needle-stitch injuries) were noted in the injury report books. Most injuries were located at the non-dominant hand, preferentially at the index finger and the thumb. Around one fifths of the injuries were at the side of handedness. The average number of injuries per month was 1.22 for the 50months prior to the introduction of cut-resistant gloves, more than seven times higher than after their introduction (0.158; 19months; p < 0.001). Considering the medical and administrational costs of such injuries, cut-resistant protective gloves are an effective and cost-effective completion of personal occupational safety measures in surgical pathology and autopsy. We strongly recommend the use of such gloves, especially for autopsy personnel.