Pitfalls in immunohistochemical assessment of EGFR expression in soft tissue sarcomas.

BACKGROUND: New targeted cancer treatments acting against growth factor receptors such as the epidermal growth factor receptor (EGFR) necessitate selecting patients for treatment with these drugs. Besides carcinomas, soft tissue sarcomas (STS) express EGFR and might thereby be a promising target for this new therapeutic strategy. OBJECTIVE: To test and compare different EGFR antibodies to determine the frequency of EGFR expression in STS. METHODS: 302 consecutive specimens of STS were examined using the tissue microarray technique. EGFR expression levels were assessed by immunohistochemistry using five different commercially available antibodies. Gene amplification status was measured by fluorescence in situ hybridisation (FISH). Immunoreactivity and amplification status were correlated with clinicopathological features and follow up data available in 163 cases. RESULTS: EGFR expression frequency ranged between 0.3% and 52.9%, depending on the antibody and scoring method used. In all, 3.5% of the tumours showed egfr gene amplification by FISH, which correlated with EGFR expression for three antibodies. Only one antibody had independent prognostic value in multivariate analysis and correlated with an unfavourable outcome; egfr gene amplification status showed no correlation with clinical features. CONCLUSIONS: Frequency of EGFR immunopositivity in STS strongly depends on the antibody used, and only one of five antibodies tested predicted an unfavourable clinical outcome. This indicates that choice of primary antibody and scoring system have a substantial impact on the determination of EGFR immunoreactivity.

Expression of early placenta insulin-like growth factor in breast cancer cells provides an autocrine loop that predominantly enhances invasiveness and motility.

Early placenta insulin-like growth factor (EPIL) is expressed by a subpopulation of the Her2-positive SKBR3 breast cancer cell line displaying high motility and transendothelial invasiveness in vitro, as recently shown by our group. As a consequence of this, we established cellular models by generating an EPIL-overexpressing SKBR3 cell line, knocked down EPIL by adding specific small interfering RNA (siRNA) to those cells and produced EPIL-enriched and depleted serum-free culture media. EPIL-expressing cells as well as EPIL-induced SKBR3 cells acquired a high capacity for transendothelial invasiveness. We observed a thin and outspread morphology caused by enhanced formation of lamellipodia, i.e. protrusions in the initial phase of motility. In parallel, Her2-positive MDAHer2 breast cancer cells also showed increased invasiveness when induced by EPIL-conditioned medium. A downstream signaling impact of EPIL could be observed in the form of reduced phosphorylation of Her2, erk1/2 and akt, while phospholipase Cgamma1 phophorylation remained unaffected. As an in vivo model for highly motile tumor cells, Paget's disease of the nipple showed simultaneous EPIL and Her2 expression upon immunohistochemical examination using specific antibodies. Such experimental data have been translated to a clinical setting by using a prognostic tissue microarray established from 603 breast cancer cases. Survival data analysis found a significant association between expression levels of EPIL and 5-year overall survival that was dose dependent: EPIL (negative) 84%, EPIL (moderately positive) 77%, EPIL (strongly positive) 48% (P < 0.005). One particular subgroup (7.6% of the cases with full clinical records) that comprised tumors simultaneously expressing EPIL and Her2 represented patients with the poorest 5-year overall survival. The results suggested that EPIL might be a cancer cell-produced growth factor that influences lateral Her2 signaling. Moreover, EPIL may be induced by factors apart from Her2 and may independently provide signaling for cancer invasion and motility.

Cytogenetic differences in breast cancer samples between German and Japanese patients.

BACKGROUND: Japanese and German breast cancer cases differ substantially in the frequency of egfr amplification. AIMS: To unravel further the cytogenetic differences between Japanese and German breast cancer cases. METHODS: Forty one Japanese breast cancer cases were evaluated by means of comparative genomic hybridisation (CGH). The results were compared with the CGH results from 161 German breast cancer cases. RESULTS: The mean number of genetic alterations/case was significantly higher in German premenopausal patients with breast cancer than in their Japanese counterparts. Japanese breast cancer cases revealed a higher number of chromosome 17p losses. Losses of 8p were associated with oestrogen receptor (ER) negativity in Japanese patients with breast cancer, whereas in the German patients gains of 3q and 6q were associated with the lack of ER expression. CONCLUSIONS: The interethnic differences of invasive breast cancer are reflected by cytogenetic aberrations, which are also associated with the differential expression of the ER.

[Bootstrapping algorithm approach reveals inherent regulatory pattern in 550 invasive breast cancer cases: CK5/6/CK14 and CK8/18/CK19 builds an antagonistic set]. / Implementierung eines Bootstrap-Algorithmus zur Evaluation Zytokeratin-abhängiger Regulationsmuster an 550 invasiven Mammakarzinomen.

All the preliminary observations on a lot of marker sets defining different stages in the tumor development are building a framework of work hypothesis which can be verified in characterising large pools of histological uniform rated paraffin probes. We developed a bootstrapping algorithm based on correlation measures to uncover regulatory patterns of immunohistochemical characterized tissue arrays with 550 invasive breast cancer cases. The algorithm is implemented in 'S' a computer language used to model mathematical solutions. Focussing on the Cytokeratins versus a set of prominent markers in breast cancer differentiation it will be obvious that markers which are known to appear in early (progenitor) forms conform to CK5/6 and CK14 while others associated with late stages conform to CK8/18 and CK19. Markers examined are among others EGFR, EMA, erb-B2, Vimentin, p53, ER and PR. The developed approach is an elegant and complete procedure to reveal the real regulatory patterns which are enclosed in a certain experimental design. The statistical significance of the results calculated by our algorithm is generally high and in the presented experimental design smaller than 0.6 * 10E-6.

Deciphering a subgroup of breast carcinomas with putative progression of grade during carcinogenesis revealed by comparative genomic hybridisation (CGH) and immunohistochemistry.

Distinct parallel cytogenetic pathways in breast carcinogenesis could be identified in recent years. Nevertheless, it remained unclear as to which tumours may have progressed in grade or which patterns of cytogenetic alteration may define the switch from an in situ towards an invasive lesion. In order to gain more detailed insights into cytogenetic mechanisms of the pathogenesis of breast cancer, the chromosomal imbalances of 206 invasive breast cancer cases were characterised by means of comparative genomic hybridisation (CGH). CGH data were subjected to hierarchical cluster analysis and the results were further compared with immunohistochemical findings on tissue arrays from the same breast cancer cases. The combined analysis of immunohistochemical and cytogenetic data provided evidence that carcinomas with gains of 7p, and to a lesser extent losses of 9q and gains of 5p, are a distinct subgroup within the spectrum of ductal invasive grade 3 breast carcinomas. These aberrations were associated with a high degree of cytogenetic instability (16.6 alterations per case on average), 16q-losses in over 70% of these cases, strong oestrogen receptor expression and absence of strong expression of p53, c-erbB2 and Ck 5. These characteristics provide strong support for the hypothesis that these tumours may develop through stages of well- and perhaps intermediately differentiated breast cancers. Our results therefore underline the existence of several parallel and also stepwise progression pathways towards breast cancer.

Expression of the p14ARF tumor suppressor predicts survival in acute myeloid leukemia.

Cell cycle aberrations are associated with therapy outcome in many types of cancer. We analyzed mRNA expression levels of 18 cell cycle-related genes in bone marrow samples from 78 acute myeloid leukemia (AML) patients and six controls using high-throughput quantitative RT-PCR. Samples of AML patients contained significantly increased mRNA expression levels of the mdm2 and c-myc oncogenes. Also, the average expression levels of p14ARF and p16INK4A were higher in patient samples compared to controls. Leukemic blasts and control bone marrow samples did not differ significantly in the expression levels of proliferation-associated genes such as cyclin A2 and pcna. When single genes were analyzed for prognostic significance in Kaplan-Meier and Cox regression analyses, a low p14ARF level emerged as a strong and independent predictor for poor survival (P=0.04 and 0.029). Subsequently, p14ARF mRNA levels were analyzed in a second, independent patient population (n=57). Again, low p14ARF levels were associated with a worse outcome. Finally, immunohistochemistry analysis of AML tissue arrays confirmed the widespread expression of c-myc and p14ARF in AML on the protein level. Taken together, the expression of the p53 regulators mdm2 and p14ARF are altered in AML, and low p14ARF levels indicate a poor prognosis.

High mobility group protein HMGA1 expression in breast cancer reveals a positive correlation with tumour grade.

Members of the HMGA protein (high mobility group protein A) family act as master switches of the chromatin structure by bending DNA and thus modulating the formation of transcription factor complexes of a number of target genes. Accordingly, HMGA proteins have been shown to be associated with the development and/or progression of a variety of benign and malignant tumours. Nevertheless, the HMGA1 expression studies published so far have not included primary breast cancer samples. In this study we have investigated the HMGA1 expression patterns in a series of 170 breast cancer samples by immunohistochemistry. We have found a strong variation in HMGA1 expression between the tumours. Based on an immunoreactive score (IRS) 14.1% of the tumour samples were scored to IRS 8-12 (strong positivity for HMGA1), 24.7% were scored to IRS 4-6 (moderate positivity), 25.3% were scored to IRS 1-3 (weak positivity), and 35.9% showed no positivity at all. Immunoreaction could be detected in all histological types of breast cancers analysed with the exception of invasive papillary and cribriform carcinoma. Statistical analysis revealed a strong correlation between tumour grade and HMGA1 expression (rs=0.3516, p<0.0001). Thus, the HMGA1 expression level can be considered a potential prognostic marker for breast cancer.

Demystified...tissue microarray technology.

Several "high throughput methods" have been introduced into research and routine laboratories during the past decade. Providing a new approach to the analysis of genomic alterations and RNA or protein expression patterns, these new techniques generate a plethora of new data in a relatively short time, and promise to deliver clues to the diagnosis and treatment of human cancer. Along with these revolutionary developments, new tools for the interpretation of these large sets of data became necessary and are now widely available. Tissue microarray (TMA) technology is one of these new tools. It is based on the idea of applying miniaturisation and a high throughput approach to the analysis of intact tissues. The potential and the scientific value of TMAs in modern research have been demonstrated in a logarithmically increasing number of studies. The spectrum for additional applications is widening rapidly, and comprises quality control in histotechnology, longterm tissue banking, and the continuing education of pathologists. This review covers the basic technical aspects of TMA production and discusses the current and potential future applications of TMA technology.

Tissue microarrays: a new approach for quality control in immunohistochemistry.

AIMS: To improve the interpretation of immunohistochemistry (IHC) staining results the use of a tissue microarray technique was established in a routine setting. METHODS: A tissue microarray was constructed by harvesting 600 microm tissue cores from paraffin wax embedded samples available in a routine pathology department. The punches originating from non-tumorous tissue were placed on host paraffin wax blocks. The microarray contained 12 different tissue samples, with a wide antigen profile and a dimension of 3.5 x 3 mm. One section of the multitissue array was placed as an "internal" positive control on each slide of the patient tissue to undergo identical immunohistochemical procedures. RESULTS: Using the tissue microarray technique as a tool for internal quality control, the interpretation of immunohistochemical staining of more than 20 different antigens in routine IHC was improved. The tissue microarray did not influence the staining results in conventional IHC or in different automated IHC settings. CONCLUSION: The regular use of an institution adapted tissue microarray would be useful for internal positive control in IHC to enable different laboratory demands. Furthermore, this technique improves the evaluation of staining results in IHC.

[Epulis in a newborn. histogenetic comparison with a granular cell tumor in adults]. / Epulis eines Neugeborenen. Histogenetischer Vergleich zum Granularzelltumor des Erwachsenen.

The congenital granular cell tumor is a rare lesion of newborns located on the alveolar ridge with a marked predilection for female infants. Histologically these tumors are characterized by large eosinophilic granular cells, similar to granular cell tumors in adults which are often seen as Abrikossoff tumors. Immunohistochemical studies revealed the different histogenesis and evolution of both these tumor entities. We report on a female newborn infant with a congenital epulis of the left anterior maxillary alveolar ridge. This case demonstrates a rare congenital tumor of newborns and reveals the histogenetic differences to granular cell tumors in adults.

[Spontaneous rupture of a pancreatic pseudocyst into the portal vein]. / Spontaner Einbruch einer Pankreaspseudozyste in die Pfortader - Fallbericht einer seltenen Komplikation bei chronischer Pankreatitis -

HISTORY AND ADMISSION FINDINGS: A 69-year-old woman complained of recurrent cramp-like symptoms in the upper abdomen. She admitted excessive alcohol intake. Physical examination revealed swelling and inflammation of both ankles. All other findings were unremarkable. INVESTIGATIONS: Sonography and computed tomography scan showed a cystic structure (5 cm) in the head of the pancreas. Biochemical testing revealed an anemia (Hb 7,5 mg/dl) and an elevated serum lipase (4494 U/l). Intestinal hemorrhage could not be confirmed by endoscopy. An involvement of parapancreatic structures with the pseudocyst could not be demonstrated by combination of endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography (CT). COURSE: The patient died unexpectedly. Autopsy showed a rupture of the pancreatic pseudocyst into the portal vein leading to portal vein thrombosis. The cause of death was an embolism of the pulmonary arteries. Postmortal reevaluation of CT and ERCP clarified diagnostic features. CONCLUSION: Erosion of peripancreatic vessels is one of the life threatening complications in chronic pancreatitis. The complication is uncommon but should be included into differential diagnosis of recurrent intestinal bleeding.

[Acute appendicitis caused by pregnancy-associated ectopic decidua. Case report and discussion of pathogenesis]. / Akute Appendizitis bei schwangerschaftsassoziierter ektoper Dezidua. Fallbericht und Uberlegungen zur Pathogenese.

The occurrence of pregnancy-associated ectopic decidua is a well-documented phenomenon. It has been observed most often in the ovaries, uterus, and cervix. An extragenital localization is less frequent and usually an asymptomatic, incidental finding. We report on a 32-year-old woman in her third trimester of pregnancy who developed acute appendicitis caused by ectopic decidua. This case illustrates a rare differential diagnosis of acute appendicitis and discusses the pathogenesis of pregnancy-associated ectopic decidua in such cases.

Detection of surface antigen 17-1A in breast and colorectal cancer.

Substantial progress has been made in detecting cell surface or intracytoplasmatic antigens to identify spread tumor cells with monoclonal antibodies (MAbs). The 17-1A antigen is already used as a target for specific immunotherapy in colorectal cancer. The purpose of this study was to compare the expression of 17-1A antigen in colorectal tumors versus breast cancers. MAb against the epithelial-specific antigen (ESA) and a routine staining technique were used to detect the 17-1A antigen in 100 cases of colorectal and 111 cases of breast cancer. The antigen expression of each tumor entity was examined by light microscopy on paraffin sections. Thirty six of the formalin-fixed paraffin sections of breast cancer were compared with their corresponding frozen sections. Evaluation was realized by a histological score (grade 0-9) considering the distribution and the staining intensity. We found an antigen expression of 17-1A in colorectal cancer quantified at 7.1+/-1.8 and at 4.5+/-2.5 for breast cancer in our score. Comparing paraffin sections and frozen sections in the 36 cases of breast cancer, the score was 5.5+/-2.3 in the paraffin and 8.1+/-1.9 in the frozen section group. Our results confirmed the high expression of 17-1A cases of in colorectal carcinoma. Furthermore, 17-1A is expressed in the majority of breast carcinomas, revealing a high difference between paraffin and frozen sections. As a result, a specific immunotherapy with MAbs against 17-1A antigen in minimal residual stages of breast cancer might be considered.

Interaction between interleukin 10 and interleukin 6 in human B-cell differentiation.

Contrary to their opposing action on human T-lymphocytes and monocytes, both Interleukin (IL-)10 and IL-6 are potent differentiation factors of human B-cells. Both are known to induce immunoglobulin (Ig) production. The precise mechanism of this converging effect of IL-6 and IL-10 remains elusive, however. Here we investigated the role of IL-6 in the IL-10 dependent B-cell differentiation into Ig secreting cells. We found that co-stimulation of SAC-stimulated human peripheral B-lymphocytes with IL-10 and IL-6 exhibited no additive effect on Ig production over stimulation with IL-10 alone, and that IL-6 receptor blockade only mildly inhibited IL-10 induced Ig synthesis. In fact, we could show that stimulation of B-cells with IL-10 somewhat suppressed SAC induced autocrine IL-6 production. Despite this suppression IL-6 levels remained sufficiently high to stimulate its receptor, and IL-6 binding to the B-cell surface was not affected. The failure of IL-6 to exert an additional effect on SAC+IL-10 induced Ig production suggests that IL-10 may recruit components of the IL-6 intracellular pathway for Ig induction. In conclusion we could demonstrate that IL-10 acts on B-cell differentiation independently of autocrine IL-6 and that it had a considerably mild effect on B lymphocytic autocrine IL-6 secretion. This still allows an IL-6 effect in the presence of IL-10 which appears adaptive with a view to the converging effects of these two cytokines on human B lymphocytes. Our study thus adds to the appreciation of the complex cytokine regulation of the immune system.

[Significance of interleukin 10 for acute graft versus host disease in children and adolescents after allogenic bone marrow transplantation]. / Die Bedeutung des Interleukin 10 für die akute Graft versus Host Erkrankung bei Kindern und Jugendlichen nach allogener Knochenmarktransplantation.

BACKGROUND: It has been shown that Interleukin 10 (IL-10) is able to inhibit alloreactivity in a mixed lymphocyte culture. Therefore, here IL-10 production in patients after allogeneic BMT was investigated and correlated with the incidence of acute GvHD. PATIENTS: 14 patients after allogeneic BMT have been investigated. Patients' age ranged from 2.6 to 22 yrs. (median 7 yrs.). Patients were diagnosed with Ewing's sarcoma (1), ALL (4), AML (3), CML (2), Wiskott-Aldrich Syndrome (WAS;1), MDS (1) and SAA (2). GvHD > II degrees occurred in 5/14 patients. As control served 20 healthy volunteers. METHODS: Mononuclear cells (MNC's) isolated from patients and 20 healthy controls were stimulated with an anti-CD3 monoclonal antibody for 72 hr. IL-10 was detected in cell-free supernatants by ELISA. RESULTS: Anti-CD3-induced IL-10 production in MNC's isolated from patients (range/median: 0-1579 pg/10(6) MNC; 221 pg/10(6) MNC) was significantly reduced compared to healthy controls (160-5093 pg/10(6) MNC; 1250 pg/10(6) MNC; p < 0.01). 4/5 patients with low IL-10 production, but only 1/9 with a normal IL-10 production presented with GvHD > II degrees (p < 0.05). CONCLUSION: Ex vivo IL-10 production was decreased in about one third of patients early after allogeneic BMT. The low IL-10 production was associated with a significantly increased risk of severe GvHD. Thus, supplementation of IL-10 might become a useful therapy to prevent GvHD.

Interleukin-10 directly inhibits the interleukin-6 production in T-cells.

IL-6 is a potent regulator of T-cell activation, proliferation and differentiation. Since IL-10 inhibits cytokine production by T cells, the effect of IL-10 on IL-6 production by T cells was investigated. IL-6 production by purified monocytes or T cells was detected from cell-free culture supernatants by ELISA after stimulation of the cells with LPS or an anti-CD3 monoclonal antibody for 3 days. Although the main source of IL-6 are LPS activated monocytes (29.6 +/- 10 ng/ml), T cells secreted sufficiently high levels of IL-6 (790 +/- 200 pg/ml) to stimulate the high affinity IL-6 receptor. IL-10 decreased anti-CD3 induced IL-6 mRNA expression by up to 80%. In addition, IL-10 significantly inhibited IL-6 release from T-cells. Highly purified, anti-CD3 activated T-cells secreted 600 +/- 150 pg/ml IL-6 compared to 21 +/- 2 pg/ml IL-6 following addition of IL-10 (10 ng/ml; P < 0.001). FACS analysis revealed a monocyte contamination of the T-cell preparations of less than 0.5%. In addition, no IL-1 production was detectable. Thus, in our experiments the effect of IL-10 on IL-6 production was independent of the presence of monocytes. Finally, inhibition of IL-6 production was not reversed by IL-2 (100 U/ml). In conclusion, IL-10 suppressed the synthesis of IL-6 by T-cells via a monocyte- and IL-2-independent mechanism. These results may help to understand the complex regulation of T-cell mediated cytokine production by IL-10.