Distributed computing in image analysis using open source frameworks and application to image sharpness assessment of histological whole slide images.

BACKGROUND: Automated image analysis on virtual slides is evolving rapidly and will play an important role in the future of digital pathology. Due to the image size, the computational cost of processing whole slide images (WSIs) in full resolution is immense. Moreover, image analysis requires well focused images in high magnification. METHODS: We present a system that merges virtual microscopy techniques, open source image analysis software, and distributed parallel processing. We have integrated the parallel processing framework JPPF, so batch processing can be performed distributed and in parallel. All resulting meta data and image data are collected and merged. As an example the system is applied to the specific task of image sharpness assessment. ImageJ is an open source image editing and processing framework developed at the NIH having a large user community that contributes image processing algorithms wrapped as plug-ins in a wide field of life science applications. We developed an ImageJ plug-in that supports both basic interactive virtual microscope and batch processing functionality. For the application of sharpness inspection we employ an approach with non-overlapping tiles. Compute nodes retrieve image tiles of moderate size from the streaming server and compute the focus measure. Each tile is divided into small sub images to calculate an edge based sharpness criterion which is used for classification. The results are aggregated in a sharpness map. RESULTS: Based on the system we calculate a sharpness measure and classify virtual slides into one of the following categories - excellent, okay, review and defective. Generating a scaled sharpness map enables the user to evaluate sharpness of WSIs and shows overall quality at a glance thus reducing tedious assessment work. CONCLUSIONS: Using sharpness assessment as an example, the introduced system can be used to process, analyze and parallelize analysis of whole slide images based on open source software.

Identification of biology-based breast cancer types with distinct predictive and prognostic features: role of steroid hormone and HER2 receptor expression in patients treated with neoadjuvant anthracycline/taxane-based chemotherapy.

INTRODUCTION: Reliable predictive and prognostic markers for routine diagnostic purposes are needed for breast cancer patients treated with neoadjuvant chemotherapy. We evaluated protein biomarkers in a cohort of 116 participants of the GeparDuo study on anthracycline/taxane-based neoadjuvant chemotherapy for operable breast cancer to test for associations with pathological complete response (pCR) and disease-free survival (DFS). Particularly, we evaluated if interactions between hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression might lead to a different clinical behavior of HR+/HER2+ co-expressing and HR+/HER2- tumors and whether subgroups of triple negative tumors might be identified by the help of Ki67 labeling index, cytokeratin 5/6 (CK5/6), as well as cyclooxygenase-2 (COX-2), and Y-box binding protein 1 (YB-1) expression. METHODS: Expression analysis was performed using immunohistochemistry and silver-enhanced in situ hybridization on tissue microarrays (TMAs) of pretherapeutic core biopsies. RESULTS: pCR rates were significantly different between the biology-based tumor types (P = 0.044) with HR+/HER2+ and HR-/HER2- tumors having higher pCR rates than HR+/HER2- tumors. Ki67 labeling index, confirmed as significant predictor of pCR in the whole cohort (P = 0.001), identified HR-/HER- (triple negative) carcinomas with a higher chance for a pCR (P = 0.006). Biology-based tumor type (P = 0.046 for HR+/HER2+ vs. HR+/HER2-), Ki67 labeling index (P = 0.028), and treatment arm (P = 0.036) were independent predictors of pCR in a multivariate model. DFS was different in the biology-based tumor types (P < 0.0001) with HR+/HER2- and HR+/HER2+ tumors having the best prognosis and HR-/HER2+ tumors showing the worst outcome. Biology-based tumor type was an independent prognostic factor for DFS in multivariate analysis (P < 0.001). CONCLUSIONS: Our data demonstrate that a biology-based breast cancer classification using estrogen receptor (ER), progesterone receptor (PgR), and HER2 bears independent predictive and prognostic potential. The HR+/HER2+ co-expressing carcinomas emerged as a group of tumors with a good response rate to neoadjuvant chemotherapy and a favorable prognosis. HR+/HER2- tumors had a good prognosis irrespective of a pCR, whereas patients with HR-/HER- and HR-/HER+ tumors, especially if they had not achieved a pCR, had an unfavorable prognosis and are in need of additional treatment options.

Endocytoscopy for the detection of microstructural features in adult patients with celiac sprue: a prospective, blinded endocytoscopy-conventional histology correlation study.

BACKGROUND: Endocytoscopy (EC) is a novel technique that allows magnified live inspection of the intestinal mucosa. OBJECTIVE: To evaluate EC for the detection of key pathological findings in patients with celiac sprue. DESIGN: A total of 166 EC recordings were prospectively acquired. Matched videos, images, and biopsy specimens were obtained by duodenal argon beamer labeling of the respective sites. SETTING: Academic tertiary referral center. PATIENTS: Forty patients (mean age 51.5 years, 70% women) with established (n = 32) or suspected (n = 8) celiac disease (CD). INTERVENTIONS: A validated scoring system (Marsh classification) was used to assess disease activity. EC criteria were independently evaluated by 2 gastroenterologists and 1 pathologist. MAIN OUTCOME MEASUREMENTS: The primary endpoint was to examine EC correlation with conventional CD histology. RESULTS: Of 166 duodenal biopsy sites, 23% were classified as Marsh III (moderate to severe), 10% as Marsh I (mild), and 67% as Marsh 0 (normal). Using the 450x magnification, we found that identification of crypts was diagnostic for celiac pathology. Four criteria were significant predictors of Marsh III pathology when adjusted by multivariate analysis: low number of villi per visual field (<3; odds ratio [OR] 9.1; 95% CI, 1.3-62.0), confluence of villi (OR 37.1; 95% CI, 1.3-1021.2), irregular epithelial lining (OR 10.9; 95% CI, 2.5-46.7), and inability to delineate loop capillaries (OR 14.9; 95% CI, 3.3-67.0). None was a good predictor of Marsh I pathology. LIMITATIONS: Single-center experience. No prospective validation of the criteria in an independent patient population. CONCLUSIONS: EC at 450x magnification accurately identifies mucosal histopathology of advanced CD, but not early morphological changes.

Core classification of lung cancer: correlating nuclear size and mitoses with ploidy and clinicopathological parameters.

We attempted to establish a microscopy based tumour characterization providing insight into the genetics of cancer cells and in particular their DNA ploidy. The core classification defined semi-quantitative criteria for scoring the nuclear size ranging from small (core score 1) to giant nuclei (core score 4). By listing all nuclear sizes according to their relative frequencies it provided a measure for core size variability as a correlate of nuclear pleomorphism. Additionally, the mitosis size, their variability and the presence/abundance of tripolar and tetrapolar mitoses were determined. This classification was applied to 155 lung cancer samples from all major histologic types and the results were correlated with the analysis by DNA image cytometry and patient survival. The morphological assessments correlated highly significantly with the DNA ploidy parameters, e.g. small cell lung carcinomas showed the smallest values for nuclear size (mean core score of 1.18) and DNA content (DNA index mean of 2.08c) being highly significantly different from adenocarcinomas (1.95/3.10c), large cell lung carcinoma (2.00/3.26c) and squamous cell carcinoma (2.20/3.42c). In non-small cell lung carcinoma (NSCLC) in general and adenocarcinoma in particular, the core size variability correlated significantly with grading and survival. Furthermore, parameters indicative for chromosomal variability, i.e. 2c deviation index and 5c exceeding rate, were predictors of poor survival in NSCLC patients. As a complement to histologic tumour diagnosis the core classification should help to better stratify cancer subtypes.

Inter-laboratory validation of PCR-based HPV detection in pathology specimens.

The detection and typing of human papilloma virus (HPV) in pathology specimens is gaining increasingly in importance. In the context of the initiative for quality assurance in pathology (QuIP) of the German Society of Pathology and the Professional Association of German Pathologists, four panel laboratories with experience and expertise in polymerase chain reaction (PCR)-based HPV detection were selected to establish an inter-laboratory trial. In a first step, these laboratories performed an internal testing of their own methodologies, which comprised DNA sequencing, multiplex nested PCR and hybridization techniques. Material from 39 samples including paraffin sections and DNA preparations of tissues and plasmids were evaluated by each panel institute according to their own protocols. Despite the different methodologies, a high degree of inter-laboratory reliability was achieved. In this report, we summarise the results. Pretested specimens are available for the external trail and can be ordered from the steering institute via provitro GmbH Berlin ( http://www.provitro.de ). Supplementary data are online available at http://pathologie-ccm.charite.de (rubric "Forschung"), which includes a web-based photo gallery of HPV-associated lesions and their potential association with specific virus types. The initiative is intended to foster the quality assurance of molecular HPV analysis in pathology and its correlation with morphological changes.

Decreased expression of insulin-like growth factor binding protein 7 in human colorectal carcinoma is related to DNA methylation.

PURPOSE: Insulin-like growth factor binding protein 7 (IGFBP-7) is considered a tumor suppressor in various cancers, but its role in colorectal cancer (CRC) is still uncertain. The aims of this study were to analyze the IGFBP-7 expression, and explore the mechanism responsible for the inactivation of IGFBP-7 in CRC. METHODS: mRNA expression was studied by RT-PCR and Northern blot analysis of cultured cells. Methylation status was analyzed by treatment with 5-aza-2'-deoxycytidine followed by sequencing of PCR products of sodium bisulfite-treated genomic DNA. IGFBP-7 protein expression was evaluated by immunohistochemistry (IHC) on tissue microarrays. RESULTS: mRNA expression was lost in six out of eight CRC cell lines as compared to normal colon cells. DNA methylation was found in the region of exon 1 and intron 1 of IGFBP-7. In tumor tissue, 107 out of 279 samples showed a negative expression of IGFBP-7 by IHC, which was significantly associated with poor prognosis. The analysis of 37 paired cancerous and normal mucosa samples confirmed the downregulation in the tumors, but revealed variable basal expression levels of IGFBP-7 in normal mucosal samples. CONCLUSIONS: DNA methylation is a mechanism responsible for IGFBP-7 gene silencing providing a target for therapeutic intervention of this tumor suppressor gene.

The diagnostic path, a useful visualisation tool in virtual microscopy.

BACKGROUND: The Virtual Microscopy based on completely digitalised histological slide. Concerning this digitalisation many new features in mircoscopy can be processed by the computer. New applications are possible or old, well known techniques of image analyses can be adapted for routine use. AIMS: A so called diagnostic path observes in the way of a professional sees through a histological virtual slide combined with the text information of the dictation process. This feature can be used for image retrieval, quality assurance or for educational purpose. MATERIALS AND METHODS: The diagnostic path implements a metadata structure of image information. It stores and processes the different images seen by a pathologist during his "slide viewing" and the obtained image sequence ("observation path"). Contemporary, the structural details of the pathology reports were analysed. The results were transferred into an XML structure. Based on this structure, a report editor and a search function were implemented. The report editor compiles the "diagnostic path", which is the connection from the image viewing sequence ("observation path") and the oral report sequence of the findings ("dictation path"). The time set ups of speech and image viewing serve for the link between the two sequences. The search tool uses the obtained diagnostic path. It allows the user to search for particular histological hallmarks in pathology reports and in the corresponding images. RESULTS: The new algorithm was tested on 50 pathology reports and 74 attached histological images. The creation of a new individual diagnostic path is automatically performed during the routine diagnostic process. The test prototype experienced an insignificant prolongation of the diagnosis procedure (oral case description and stated diagnosis by the pathologist) and a fast and reliable retrieval, especially useful for continuous education and quality control of case description and diagnostic work. DISCUSSION: The Digital Virtual Microscope has been designed to handle 1000 images per day in the daily routine work of a pathology institution. It implies the necessity of an automatic mechanism of image meta dating. The non - deterministic correlation between the oral statements (case report) and image information content guides the image meta dating. The presented software opens up new possibilities for a content oriented search in a virtual slide, and can successfully support medical education and diagnostic quality assurance.

Cytokeratin profiles identify diagnostic signatures in colorectal cancer using multiplex analysis of tissue microarrays.

BACKGROUND AND AIMS: Recent cDNA expression profiling analyses indicate that within specific organ cancers Cytokeratins (CKs) dysregulation may identify subgroups with distinct biological phenotypes. Our objectives in this study were (1) to test whether cytokeratins were also distinct on the protein level, (2) to evaluate these biomarkers in a series of well-characterised CRCs, (3) to apply hierarchical cluster analysis to immunohistochemical data. METHODS: Tissue microarrays (TMA) comprising 468 CRC specimens from 203 patients were constructed to evaluate CK5, CK7, CK8, CK13, CK14, CK16, CK17, CK18, CK19 and CK20. In total, 2919 samples were analyzed. RESULTS: Unsupervised hierarchical clustering discovered subgroups represented by reduced CK8 and CK20 expression, that differed by a shorter patients survival. The evaluation of the specific biomarkers by Kaplan-Meier analysis showed that reduced CK8 expression (p<0.01) was significantly associated with shorter patients' survival, but was not an independent factor correlated with tumour stage (pT), grading (G) and nodal stage (pN). CONCLUSIONS: Reduced coexpression of CK8 and CK20 may indicate an epithelial-mesenchymal transition (EMT) representing an important step in the development of more aggressive CRCs. In addition, multiplex analysis of TMAs together with immunohistochemistry (IHC) supplemented by hierarchical clustering are a useful, promising and very powerful tool for the identification of tumour subgroups with diagnostic and prognostic signatures.

HPV typing and CGH analysis for the differentiation of primary and metastatic squamous cell carcinomas of the aerodigestive tract.

Human papilloma virus (HPV) typing and Comparative Genomic Hybridisation (CGH) analysis can be used in the classification of multiple tumours of the aerodigestive tract for the differentiation between secondary malignancy versus metastasis. We present 3 exemplary cases of patients with multiple squamous cell carcinomas, localised within the head and neck region, cervical lymph node and the lung. In two patients, HPV typing identified HPV type 16 in the tonsillar carcinomas and the corresponding cervical lymph node and lung carcinoma indicating that the latter were metastatic spreads. In case 1, CGH confirmed the clonal relationship. Case two showed a peculiar syncytial growth pattern with lymphocytic infiltration which may constitute a potential morphological marker for HPV infection. In case three, a vallecular carcinoma was HPV negative while a lung cancer was positive for HPV type 6 indicating two independent primary tumours. Our case triplet illustrates the variability of HPV infection in squamous cell cancer of the aerodigestive tract and power as well as limitations of morphology, HPV typing and tumour genetics in the classification of multiple tumours.

Immunoprofiles of 11 biomarkers using tissue microarrays identify prognostic subgroups in colorectal cancer.

BACKGROUND AND AIMS: Genomewide expression profiling has identified a number of genes expressed at higher levels in colorectal cancer (CRC) than in normal tissues. Our objectives in this study were: 1) to test whether genes were also distinct on the protein level; 2) to evaluate these biomarkers in a series of well-characterized CRCs; and 3) to apply hierarchical cluster analysis to the immunohistochemical data. METHODS: Tissue microarrays (TMAs) comprising 351 CRC specimens from 270 patients were constructed to evaluate the genes Adam10, Cyclin D1, Annexin II, NFKB, Casein kinase 2 beta (CK2B), YB-1, P32, Rad51, c-fos, IGFBP4, and Connexin26 (Cx26). In total, 3,797 samples were analyzed. RESULTS: Unsupervised hierarchical clustering discovered subgroups of CRC that differed by tumor stage and survival. Kaplan-Meier analysis showed that reduced Cx26 expression was significantly associated with shorter patient survival and higher tumor grade (G1/G2 vs G3, P = .02), and Adam10 expression with a higher tumor stage (pT1/2 vs pT3/4, P = .04). CONCLUSIONS: Our study highlights the potential of TMAs for a higher-dimensional analysis by evaluating serial sections of the same tissue core (three-dimensional TMA analysis). In addition, it endorses the use of immunohistochemistry supplemented by hierarchical clustering for the identification of tumor subgroups with diagnostic and prognostic signatures.

Inter-laboratory validation of PCR-based detection of Mycobacterium tuberculosis in formalin-fixed, paraffin-embedded tissues.

The present study is based on the initiative for quality assurance in pathology of the German Society of Pathology and the Professional Association of German Pathologists. Four panel laboratories with experience and expertise in polymerase chain reaction (PCR) detection of Mycobacterium tuberculosis were selected to establish the prerequisites for continuous external laboratory trials, in particular, by providing pre-tested specimens and evaluation criteria for participating institutes. In the first step, the four panel laboratories performed an internal trial to test their own reliability and reproducibility. Paraffin sections and DNA preparations from 34 tissues (25 clinical specimens and 9 controls) totalling to 66 samples were evaluated by each panel institute according to their own protocols. The methodologies differed and are described in detail. Despite these differences, a high degree of inter-laboratory reliability was achieved. In this report, we summarise our results including the correlation with the histology and provide recommendations for applying PCR-based methodology for the detection of mycobacterial DNA in surgical specimens. Supplementary data are available online at http://www.charite.de/ch/patho (rubric "Forschung"). Pre-tested specimens are now available for the external trial and can be ordered from the steering institute via Oligene (http://www.oligene.com/). All molecular pathology laboratories are invited to participate in this quality assurance initiative.

Differentially expressed genes associated with human lung cancer.

To investigate the gene expression of 9 cDNA clones generated by suppression subtraction hybridization (SSH), Northern blot analysis was performed on a panel of immortalized bronchial epithelial cell lines, lung cancer cell lines and normal human bronchial epithelial cells (HBEC). The clones were located on chromosomes 1q, 2q, 3p, 3q, 4q and 14q representing regions that are frequently affected by DNA imbalances as shown by comparative genomic hybridization (CGH). Two were unknown (H24, H103) whereas the others matched to the Pest-containing nuclear protein (H52), Rp11-767C1 gene (H134), the hypothetical gene AK025444 (H238), Guanine nucleotide binding protein (G protein)/alpha inhibiting activity polypeptide 2 (H268), Laminin gamma 1 (Y45), the DEAD (Asp-Glu-Ala-Asp/His) box polypeptide 9 (Y162) and the heat shock 90 kDa protein 1, alpha (Y238). Northern blot results indicated that all of the studied clones showed differential up- or down-regulation in immortalized cells and lung cancer cell lines. Of those, clone Y238 representing HSP90alpha showed a clearly over-expressed transcript. Subsequently, semi-quantitative RT-PCR was used to further confirm the over-expression of Y238, indicating that HSP90alpha was significantly over-represented in 49 primary lung tumors as compared to 14 normal lung samples (P<0.01). CGH showed that the majority of studied lung cancer cell lines (71.4%) carried an overrepresentation at 14q32 where HSP90alpha is located suggesting that it may be affected by DNA copy number changes. The further characterization of these clones will provide us with valuable information on its role in lung carcinogenesis and may help to develop new diagnostic or therapeutic targets for this lethal disease.

Chromosomal alterations in lung metastases of colorectal carcinomas: associations with tissue specific tumor dissemination.

Comparative genomic hybridization was used to screen colorectal carcinomas for chromosomal aberrations that are associated with the metastatic phenotype of the lung. Specimens of 13 lung metastases, 6 primary tumors, 1 lymph node metastasis, 1 liver metastasis, and 1 ovarian metastasis were investigated and added to our CGH colon cancer tumor collective, comprising 85 tumor specimens from 56 patients (see CGH online tumor database at http://amba.charite.de/cgh). Lung metastases showed more alterations than liver metastases, particularly more deletions at 1p, 3p, 9q, 12q, 17q, 19p and 22q and gains at 2q, 5p, and chromosome 6. Comparing lung metastases with their corresponding primary tumors, particularly more deletions at 3p, 8p, 12q, 17q, and 21q21 and gains at 5p were observed. Based on our results, we wish to suggest a metastatic progression model. Specific subpopulations of metastatic cells have a distinct metastatic potential, which is reflected by a non-random accumulation of chromosomal alterations. Distinct alterations already exist within the primary tumor and this "ready to go package" gives the cells the metastatic potential to achieve the complex series of events needed for metastasis.

[Evaluation of p63 expression in lung cancer by use of complementary DNA and tissue microarray].

OBJECTIVE: To study p63 expression at mRNA transcript and protein levels in human lung cancers, including squamous cell lung carcinoma (SCC), adenocarcinoma, large cell lung carcinoma (LCLC) and small cell lung carcinoma (SCLC), or the corresponding metastatic foci. The relationship of p63 expression and alterations in p63 locus at chromosomal 3q27-29 was also determined. METHODS: p63 gene expression in 72 cases of SCC, adenocarcinoma, LCLC and SCLC was analyzed by cDNA microarray technology. Tissue microarray of specimens from 150 cases of primary lung cancer was prepared for immunohistochemical study for p63 protein. Possible chromosomal alterations at the p63 locus in 70 cases of primary lung cancer were studied by comparative genomic hybridization (CGH) technology. RESULTS: p63 mRNA transcript expression was significantly increased by more than 10-fold in SCC, as compared with that in other histologic subtypes including adenocarcinoma, LCLC and SCLC. p63 mRNA expression in metastatic foci was also remarkably higher than that in their primary tumors (P < 0.001). Immunostaining showed that p63 protein expression was observed in 94.64% of SCC, whereas only one lung adenocarcinoma (1.79%) was positive. Immunopositivity was also demonstrated in 2 of the 4 LCLC cases studied. None of the SCLC cases was positive. There was a statistically significant difference in p63 expression between pT1 and pT2 tumors (P < 0.05). The CGH results showed that overrepresentation of p63 locus at chromosomal 3q27-29 was a typical finding in SCC. p63 immunopositivity also correlated significantly with pronounced gains of p63 locus at chromosomal 3q27-q29 (P < 0.000 1), suggesting that strong expression of p63 in lung SCC was associated with increased gene amplification. CONCLUSION: p63 may play a role in oncogenesis of human lung squamous cell carcinoma and development of metastasis.

Chromosomal alterations during lymphatic and liver metastasis formation of colorectal cancer.

Comparative genomic hybridization (CGH) was used to screen colorectal carcinomas for chromosomal aberrations that are associated with metastatic phenotype. In total, 63 tumor specimens from 40 patients were investigated, comprising 30 primary tumors, 22 systemic metastases (12 liver, 6 brain, and 4 abdominal wall metastases) and 11 lymph node tumors. Using statistical analysis and histograms to evaluate the chromosomal imbalances, overrepresentations were detected most frequently at 20q11.2-20q13.2, 7q11.1-7q12, 13q11.2-13q14, 16p12, 19p13, 9q34, and 19q13.1-19q13.2. Deletions were prominent at 18q12-18q23, 4q27-4q28, 4p14, 5q21, 1p21-1p22, 21q21, 6q16-6q21, 3p12, 8p22-8p23, 9p21, 11q22, and 14q13-14q21. Hematogenous metastases showed more alterations than lymph node tumors, particularly more deletions at 1p, 3, 4, 5q, 10q, 14, and 21q21 and gains at 1q, 7p, 12qter, 13, 16, and 22q. Comparing liver metastases with their corresponding primary tumors, particularly deletions at 2q, 5q, 8p, 9p, 10q, and 21q21 and gains at 1q, 11, 12qter, 17q12-q21, 19, and 22q were more often observed. The analysis suggested that the different pathways of tumor dissemination are reflected by a nonrandom accumulation of chromosomal alterations with specific changes being responsible for the different characteristics of the metastatic phenotype.

Overexpression of cyclooxygenase-2 correlates with chromosomal gain at the cyclooxygenase-2 locus and decreased patient survival in advanced colorectal carcinomas.

PURPOSE: Overexpression of cyclooxygenase-2 is observed in a variety of malignancies including colorectal cancer. However, to date, cyclooxygenase-2 expression by advanced human colorectal cancers and their metastases has been poorly characterized. This study was designed to evaluate the rate of cyclooxygenase-2 overexpression in our tumor collection and to clarify its correlation with the chromosomal status at the cyclooxygenase-2 locus in colorectal cancer. METHODS: Seventy-four specimens were analyzed immunohistochemically using a monoclonal cyclooxygenase-2 antibody. The staining was scored semiquantitatively as: -, negative; +, weak; ++, moderate; and +++, strong positive. Of these, 45 specimens were analyzed using comparative genomic hybridization and immunohistochemistry. We correlated the cyclooxygenase-2 overexpression with the chromosomal gain of 1q25.2-q25.3 and patients survival and compared primary colorectal cancers and their paired metastases at the DNA and protein level. RESULTS: Overexpression was observed in 58 percent of the cases (score > or = ++). Chromosomal gains at the cyclooxygenase-2 locus were clearly correlated with overexpression of the gene (P=0.009). Furthermore, the comparison of paired tumor samples showed additional overrepresentation in the metastases at the cyclooxygenase-2 locus, which could be confirmed by immunohistochemistry. Kaplan-Meier analysis showed that overexpression of cyclooxygenase-2 was significantly associated with poor survival and thus could serve as a prognostic marker. CONCLUSIONS: We conclude that cyclooxygenase-2 is related with tumor progression and metastasis in colorectal cancer, which can be observed on protein level, and reflects chromosomal gain at the locus at 1q25.2-q25.3.

Analysis of the RNA helicase A gene in human lung cancer.

In this study we investigated the RNA helicase A (RHA) gene localized on chromosome 1q25 in 15 lung cancer cell lines, 54 primary carcinomas, bronchial epithelial cells and normal lung. Both RT-PCR and real-time RT-PCR showed that RHA is over-expressed in tumour samples compared to normal lung tissues (p=0.01). There was a tendency for higher expression levels in small cell lung cancer compared to non-small cell carcinomas. Over-expression of Y-162 correlated with high grade tumours (p=0.023). However, there was no correlation with tumour stage and survival. Our observations are compatible with the role of RHA in lung cancer development.

CD24 expression is a new prognostic marker in breast cancer.

PURPOSE: CD24 is expressed in hematological malignancies as well as in a large variety of solid tumors including breast cancer. We aimed to evaluate CD24 protein expression in breast cancer and to correlate to clinicopathological data including patient survival. EXPERIMENTAL DESIGN: Primary breast carcinomas (201) with a mean clinical follow-up time of 53 months were immunostained using a monoclonal CD24 antibody (Ab-2, clone 24C02). The staining was evaluated as negative versus positive for statistical analysis. RESULTS: In invasive breast carcinomas, CD24 expression was observed in 84.6% of cases. In univariate survival analyses, a significant association of CD24 expression with shortened patient overall survival (5-year survival rate 91.9% versus 83.8%; P = 0.031; log rank test) and disease-free survival (5-year progression rate 88.3% versus 57.0%; P = 0.0008) was demonstrated. In multivariate analyses CD24, tumor grading and nodal status were significant prognostic parameters for shortened disease-free survival. CONCLUSIONS: Our data suggest that CD24 expression in primary breast cancer as detected by immunohistochemistry might be a new marker for a more aggressive breast cancer biology.

Expression of the cell adhesion molecule CD146/MCAM in non-small cell lung cancer.

Expression of MCAM is observed in a variety of human malignancies. We aimed to determine the rate of MCAM expression in our non-small cell lung cancer (NSCLC) collection and to clarify its correlation with clinicopathological parameters and patient survival. 85 NSCLC were analysed immunohistochemically using a monoclonal MCAM antibody (clone N1238) on an NSCLC tissue micro array. The staining was semiquantitatively scored. We found MCAM expression in 51% of NSCLC, preferentially squamous cell carcinomas (p=0.004). No other correlations to tumour size, grade, or stage were found. Univariate survival analysis showed no significant differences of MCAM positive and negative tumours. In adenocarcinomas however, MCAM positivity was significantly associated with shorter patient survival (p=0.016). We conclude, that MCAM is expressed in a high proportion of NSCLC and might be predictive of shortened patient survival in adenocarcinomas of the lung. Colour figure can be viewed on http://www.esacp.org/acp/2003/25-2/kristiansen.htm

Identification of differentially expressed genes in immortalized human bronchial epithelial cell line as a model for in vitro study of lung carcinogenesis.

Suppression subtractive hybridization (SSH) was applied to identify differentially expressed genes in the SV40LT immortalized human bronchial epithelial cell line Y-BE, with normal human bronchial epithelial cells (HBEC) as a control. Two cDNA libraries of up- and downregulated genes were generated, comprising 218 known genes and 131 unknown genes in total. The expression of 22 clones from the 2 libraries was investigated by Northern blot analysis, and 86.4% (19/22) of them showed differential expression between Y-BE cells and HBEC. Although the Y-BE cells are nontumorigenic in nude mice, Comparative genomic hybridization (CGH) detected some DNA imbalances in Y-BE cells that were similar to lung cancer cells. Our data demonstrate that the studied cell line Y-BE and SSH is a reliable approach for identifying new genes that are associated with immortalization and early tumor development that may help to understand the pathogenesis of lung cancer.