Klaus-Jürgen Winzer

Expression of the ELAV-like protein HuR is associated with higher tumor grade and increased cyclooxygenase-2 expression in human breast carcinoma

Purpose: The human ELAV (embryonic lethal abnormal vision)-like protein HuR stabilizes a certain group of cellular mRNAs that contain AU-rich elements in their 3′-untranslated region. Cell culture studies have shown that the mRNA of cyclooxygenase (COX)-2 can be stabilized by HuR. Experimental Design: To investigate a possible contribution of dysregulation of mRNA stability to the progression of cancer and to overexpression of COX-2, we studied expression of HuR in 208 primary breast carcinomas by immunohistochemistry. Results: There were two different staining patterns of HuR in tumor tissue of breast carcinomas: nuclear expression was seen in 61% of cases; and an additional cytoplasmic expression was seen in 30% of cases. Expression of HuR was significantly associated with increased COX-2 expression; this association was particularly significant for cytoplasmic HuR expression (P < 0.0005). We further observed a significant association of cytoplasmic (P = 0.002) or nuclear HuR (P = 0.027) expression with increased tumor grade. Only 13% of the grade 1 carcinomas showed cytoplasmic expression of HuR, compared with 46% of the grade 3 carcinomas. There was no significant correlation between HuR expression and other clinicopathological parameters such as histological type, tumor size, or nodal status as well as patient survival. Conclusions: Our results suggest that overexpression of HuR in tumor tissue may be part of a regulatory pathway that controls the mRNA stability of several important targets in tumor biology, such as COX-2. Based on our results, additional studies are necessary to investigate whether HuR might be a potential target for molecular tumor therapy.

Cytoplasmic overexpression of ALCAM is prognostic of disease progression in breast cancer

Background: Activated leucocyte cell adhesion molecule (ALCAM, CD166) is a cell surface member of the immunoglobulin superfamily. ALCAM expression has prognostic relevance in prostate and colon cancer. Objective: To evaluate ALCAM protein expression in breast cancer by immunohistochemistry and to correlate expression levels with clinicopathological data. Methods: 162 primary breast carcinomas with a mean clinical follow up time of 53 months were immunostained using a monoclonal ALCAM antibody. The staining was evaluated as an immunoreactive score (IRS) and grouped into low v high for both membranous and cytoplasmic staining. Results: Intraductal and invasive carcinomas showed a higher ALCAM expression (median IRS 4 and 6 respectively) than normal breast tissue (IRS 2). In univariate survival analyses a significant association of high cytoplasmic ALCAM expression with shortened patient disease-free survival (mean (SD) five year non-progression rate, 69.4 (4.6)% v 49.4 (11.1)%, p = 0.0142) was found. In multivariate analyses of disease-free survival times, high cytoplasmic ALCAM expression (relative risk (RR) = 2.086, p = 0.026) and nodal status (RR = 2.246, p = 0.035) were significantly associated with earlier disease progression, whereas tumour grading (RR = 1.6, p = 0.052) was of borderline significance. Conclusions: The data suggest that strong cytoplasmic ALCAM expression in primary breast cancer, as detected by immunohistochemistry, might be a new marker for a more aggressive breast cancer biology.

Polo-like kinase isoforms in breast cancer: expression patterns and prognostic implications.

Polo-like kinase (PLK) family members are known to be functionally involved in mitotic signaling and in cytoskeletal reorganization in both normal and malignant cells. In this study, expression of PLK1 and PLK3 was determined immunohistochemically in tissue specimens of 135 breast carcinomas, and expression was correlated with clinicopathological parameters and patient prognosis. Strong PLK isoform overexpression was observed in 42.2% (PLK1) and 47.4% (PLK3) of breast carcinomas when compared with non-transformed breast tissue. A positive correlation of PLK isoform expression with tumor grade, vascular invasion, erbB2/HER-2 expression and markers of proliferative activity was evident. Additionally, an inverse correlation of PLK isoform expression and estrogen receptor status was observed. Overexpression of PLK3 but not of PLK1 was significantly linked to reduced median overall (P<0.001) and relapse-free (P=0.021) survival time. PLK3 expression remained an independent prognostic factor for overall (RR=3.2, P=0.002) and relapse-free (RR=2.9, P=0.049) survival in multivariate survival analysis. These results suggest PLK3 as a novel independent prognostic marker in breast cancer and hint toward a role for PLK isoform overexpression in disease progression. Therefore, in vivo inhibition of PLK family members might represent a rewarding approach in the development of new anticancer drugs for this tumor entity.

Differential expression of histone deacetylases HDAC1, 2 and 3 in human breast cancer - overexpression of HDAC2 and HDAC3 is associated with clinicopathological indicators of disease progression

BackgroundIn breast cancer, the role of epigenetic alterations including modifications of the acetylation status of histones in carcinogenesis has been an important research focus during the last years. An increased deacetylation of histones leads to increased cell proliferation, cell migration, angiogenesis and invasion. Class 1 histone deacetylases (HDAC) seem to be most important during carcinogenesis.MethodsThe immunhistochemical expression of HDAC1, 2 and 3 was analyzed on tissue microarrays (TMAs) from 238 patients with primary breast cancer. We analyzed the nuclear staining intensity (negative, weak, moderate, strong) as well as the percentage of positive tumor cells and calculated the immunoreactivity score (0–12). Expression was correlated with clinicopathological parameters and patient survival.ResultsIn this cohort, we found a differential positive expression of HDAC1, HDAC2 and HDAC3. HDAC2 and HDAC3 expression was significantly higher in less differentiated tumors: HDAC2 (n=207), p<0.001 and HDAC3 (n=220), p<0.001 and correlated with negative hormone receptor status: HDAC2 (n=206), p=0.02 and HDAC3 (n=219), p=0.04. Additionally, a high HDAC2 expression was significantly associated with an overexpression of HER2 (n=203, p=0.005) and the presence of nodal metastasis (n=200, p=0.04).HDAC1 was highly expressed in hormone receptor positive tumors (n=203; p<0.001).ConclusionAs a conclusion, our results show that the class-1 HDAC isoenzymes 1, 2 and 3 are differentially expressed in breast cancer. HDAC2 and HDAC3 are strongly expressed in subgroups of tumor with features of a more aggressive tumor type.

Prognostic Relevance of AGR2 Expression in Breast Cancer

Purpose: We aimed to evaluate the expression of the human anterior gradient-2 (AGR2) in breast cancer on RNA and protein level and to correlate it with clinicopathologic data, including patient survival. Experimental Design:AGR2 mRNA expression was assessed by reverse transcription-PCR in 25 breast cancer samples and normal tissues. A polyclonal rabbit AGR antiserum was used for immunohistochemistry on 155 clinicopathologically characterized cases. Statistical analyses were applied to test for prognostic and diagnostic associations. Results: Immunohistochemical detection of AGR2 was statistically significantly associated with positive estrogen receptor status and lower tumor grade. AGR2-positive tumors showed significantly longer overall survival times in univariate analyses. For the subgroup of nodal-negative tumors, an independent prognostic value of AGR2 was found. Conclusions: The expression of AGR2 in breast cancer is strongly associated with markers of tumor differentiation (estrogen receptor positivity, lower tumor grade). A prognostic effect of AGR2 for overall survival could be shown, which became independently significant for the group of nodal-negative tumors.

Quantitative determination of estrogen receptor, progesterone receptor, and HER2 mRNA in formalin-fixed paraffin-embedded tissue--a new option for predictive biomarker assessment in breast cancer.

The development of optimized therapy strategies against malignant tumors is critically dependent on the assessment of tissue-based biomarkers in routine diagnostic tissue samples. We investigated a novel, fully automated, and xylene-free method for RNA isolation and biomarker determination using formalin-fixed paraffin-embedded (FFPE) tissue. The aim was to show that this approach is feasible and gives results that are comparable to the current gold standards. Expression of the breast cancer biomarkers ESR1, PGR, and HER2 was measured in a total of 501 FFPE tissue samples from 167 breast carcinomas, which had been stored for up to 21 years. Total RNA was extracted from tissue sections and biomarker expression was measured by kinetic RT-PCR (RT-kPCR). The results of the new method were compared with immunohistochemistry as the current gold standard. RNA was successfully isolated from all samples, with a mean yield of 1.4 &mgr;g/sample and fragment lengths of at least 150 bp in 99% of samples. RT-kPCR analysis of ESR1, PGR, and HER2 was possible in all samples. Comparing RT-kPCR results with standard IHC, we found a good concordance for ESR1 (agreement: 98.4%), PGR (84.4%), and HER2 (89.8%). We observed a low section-to-section variability of kPCR results for all 3 biomarkers (root of mean squared errors: 0.2 to 0.5 Ct values). The new approach is a reliable high-throughput instrument for standardized testing of biomarkers in clinical routine and for research studies on archived FFPE material up to 21 years old. For the assessment of ESR1, PGR, and HER2 the results are comparable to the current gold-standard.

Molecular and clinical dissection of CD24 antibody specificity by a comprehensive comparative analysis.

CD24 is a small, highly glycosylated cell surface protein that is linked to the membrane through a glycosyl-phosphatidylinositol anchor. It is overexpressed in many human carcinomas and its expression is linked to bad prognosis. Lately, lack or low expression of CD24 was used to identify tumor stem cells resulting in conflicting data on the usefulness of this marker. In many immunohistochemical studies, the mAb SN3b was used but the epitope and specificity of this antibody have never been thoroughly investigated. In other studies based mainly on cytofluorographic analysis, the mAb ML-5 was applied. In this study, we compared the epitope of mAb SN3b to the CD24 mAbs SWA-11 and ML-5 that both bind to the core protein of CD24. Using tissue microarrays and affinity-purified CD24 glycoforms, we observed only a partial overlap of SN3b and SWA11 reactivity. The mAb SN3b recognizes sialic acid most likely on O-linked glycans that can occur independently of the CD24 protein backbone. The SN3b epitope was not related to common sialylated cancer-associated glycan structures. Both SN3b epitope positive or negative CD24 glycoforms supported the binding of P-selectin and Siglec-5. In breast cancer, the SN3b reactivity was associated with bad prognosis, whereas SWA11 was not. In renal cell cancer, the SN3b epitope was completely absent but SWA11 reactivity was a prognostic factor. Our results shed new light on the tumorbiological role of CD24 and resolve discrepancies in the literature related to the use of different CD24 mAbs.

Radiation therapy and tamoxifen after breast-conserving surgery: Updated results of a 2 × 2 randomised clinical trial in patients with low risk of recurrence

To study the role of radiotherapy and tamoxifen after breast-conserving surgery (BCS) in patients with a favourable prognosis, a clinical trial was initiated by the German Breast Cancer Study Group (GBSG-V). Between 1991 and 1998, 361 patients (pT 1pN0M0, aged 45-75 years, receptor positive, grades I and II) were randomised to radiotherapy (yes/no) and tamoxifen for 2 years (yes/no) in a 2 x 2-factorial design; the exclusion of seven centres (14 patients) left 347 patients for the analysis. First results after a median follow-up of 5.9 years were published. Herein we present updated results after a median follow-up of about 10 years. Hundred and eleven events concerning event-free survival (EFS) have been observed. Since a strong interactive effect between radiotherapy and tamoxifen has been established, the results are presented in terms of the treatment effects for all four treatment groups separately. Mainly due to the presence of local recurrences, the event rate was much higher in the group with BCS only than in the other three groups. No significant difference could be established between the four treatment groups for distant disease-free survival rates (DDFS). Updated results give further evidence that even in patients with a favourable prognosis, the avoidance of radiotherapy and tamoxifen after BCS increases the rate of local recurrences substantially. Rates are about three times higher in the BCS only group. For the two outcomes EFS and DDFS, no important difference could be seen between the three groups with an additional treatment. However, because of the limited sample size with corresponding low power the strength of evidence for such a comparison is weak.

Long-term analysis to objectify the tumour grading by means of automated microscopic image analysis of the nucleolar organizer regions (AgNORs) in the case of breast carcinoma

BackgroundApart from a number of cases of inaccurate prognosis in regard to individual patients, the inter- and intra-observer variability of the classical, histological prognosis parameters have been under repeated discussion. For this reason, a long-term analysis was carried out in regard to overall survival by means of automated microscopic image analysis of the nucleolar organizer regions (AgNORs) to objectify tumour grading in the case of breast carcinoma.This consists of a selective representation of argyrophilic proteins that are associated with the nucleolus organising regions.MethodsThe evaluation included 244 female patients with an average age of 59.3 years. The characterisation of the histological sections was carried out on the basis of the AMBA/R system. With this software the histometric characterisation level was evaluated in terms of the nucleolus organizer regions. The post-observation data were obtained from the clinical register and were complemented by mortality data from the cancer registers and by data supplied by the residents’ registration office of Berlin.ResultsThe average post-observation period was 106.6 months. With the Cox-Regression the influence of the co-variables (conventional prognosis parameters and AgNOR parameters) were examined. In the model, only the parameters pN, G and various AgNOR parameters remain present.ConclusionThere is a strong correlation between survival and selected AgNOR parameters. These could replace the conventional grading as the standard measure for the mitosis rate together with the pleomorphism level. Instead of the-time consuming AMBA/R system originally used, a new implementation of AgNOR quantification with modern VM systems could be applied.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1449591192859058.

Different Proliferation Patterns in Breast Cancer: AgNOR Measurements in ER-Negative and ER-Positive Tumor Cells

The relation between estrogen receptors (ER) and argyrophilic nucleolar organizer regions (AgNORs) in situ within human breast cancer cells was analyzed. For AgNOR measurements in 49 invasive breast carcinomas, a new reproducible staining method for dual demonstration of ER and AgNORs was applied. Quantitative AgNOR variables were determined in ER‐positive and ER‐negative tumor cells by digital image analysis. The relationships between AgNOR parameters of ER‐positive and ER‐negative cells and other prognostic factors of breast cancer [Bloom–Richardson‐Grading and growth fraction (Ki‐67 index)] were investigated. A higher AgNOR content in ER‐negative cells and a special clustering phenomenon in ER‐positive tumor cells were found. Correlation with other criteria of malignant potential could be exclusively demonstrated for ER‐negative cells. ER‐negative cells of breast cancer can be characterized as the more malignant and possibly prognosis‐dictating cell fraction. Thus, ER‐negative cells probably contribute more to the progression of the tumor disease and furthermore to the prognosis than ER‐positive cells. We recommend measurement AgNORs exclusively in ER‐negative cells of breast cancer.