Biomedical subjects

G Auer

Publications and source records attributed to G Auer.

At least 19 recordsLinked to original sources

PubMed2006

Frequent gain of the human telomerase gene TERC at 3q26 in cervical adenocarcinomas.

The level of genomic amplification of the human telomerase gene TERC, which maps to chromosome band 3q26, was determined in primary cervical adenocarcinomas. Interphase nuclei prepared from archival material of 12 primary cervical adenocarcinomas, eight of which were human papillomavirus positive, were hybridised with a triple colour probe set specific for centromeres of chromosomes 3 and 7 and the TERC gene. We observed high proportions of nuclei with increased absolute copy numbers for TERC in all tumours (mean 3.3; range 2.3-5.2). Amplification of the human telomerase gene TERC is a consistent aberration in cervical adenocarcinomas. Therefore, application of our probe set may provide an objective genetic test for the assessment of glandular cells in Pap smears and hence for the diagnosis of cervical adenocarcinomas.

Adenocarcinoma↗

PubMed2005

Tumour budding detected by laminin-5 {gamma}2-chain immunohistochemistry is of prognostic value in epidermoid anal cancer.

BACKGROUND: Markers for guidance with regard to individual prognosis and treatment planning are sought in epidermoid anal cancer. This study assessed the prognostic and predictive value of tumour budding. PATIENTS AND METHODS: From a population-based consecutive series of patients who were prospectively recorded, it was possible to investigate 209 (76%) of the pretreatment biopsies. Immunohistochemistry with a monoclonal antibody for the gamma2 chain of laminin-5 was used to detect tumour budding (defined as dissociated single cancer cells or clusters of up to five cells). RESULTS: Tumour budding was detected in 104 (50%) of the 209 samples. No significant correlation was found between tumour budding and clinicopathological characteristics. Patients with tumour budding had a statistically significantly better 5-year overall survival rate compared with patients lacking tumour budding (74% versus 64%, P <0.05). Albeit not statistically significant, other outcome variables such as tumour-specific survival, recurrence after initial complete response and rate of distant metastases, were all in favour of patients with tumour budding. Multivariate analysis reveals tumour budding as an independent positive prognostic factor. CONCLUSIONS: Tumour budding detected by laminin-5 immunohistochemistry may be of prognostic value in the treatment of epidermoid anal cancer. However, further studies are needed to clarify the possible clinical implications.

Adult↗

PubMed2005

Characterisation of breast fine-needle aspiration biopsies by centrosome aberrations and genomic instability.

Recent studies have suggested that aneuploidy in malignant tumours could be a consequence of centrosome aberrations. Using immunofluorescence analysis with an antibody against gamma-tubulin and DNA image cytometry, we measured centrosome aberrations and DNA ploidy patterns in fine-needle aspiration biopsies (FNABs) of 58 breast lesions. Benign lesions did not show any centrosome aberrations. DNA diploid carcinomas showed a mean percentage of cells with centrosomal defects of 2.1%. The aneuploid invasive carcinomas could be divided into two subgroups by their significantly (P=0.0003) different percentage of cells with centrosome aberrations (2.0 and 10.3%, respectively) and their significantly (P=0.0003) different percentage of cells with nonmodal DNA content values determined by the Stemline Scatter Index (SSI), a measure of genomic instability. The percentage of cells with centrosome aberrations demonstrated a positive, linear correlation with the corresponding SSI (r=0.82, P<0.0001) and loss of tissue differentiation (r=0.78, P<0.0001). Our results indicate the percentage of cells with centrosome aberrations as being sufficient to divide the investigated tumours into three significantly different groups: benign lesions with no centrosomal aberrations, and two malignant tumour types with mean values of 2.1 and 9.6% of centrosomal defects, respectively. Together, these results demonstrate that centrosome aberrations correlate with genomic instability and loss of tissue differentiation. Furthermore, this study shows the feasibility of centrosomal analysis in FNAB of the breast and suggests centrosomal aberrations as possessing diagnostic and prognostic value.

Adult↗

PubMed2005

Proteomics and clinical surgery.

This article concludes the Journal's "Scientific Surgery" series of leaders. The series, published throughout 2005, has highlighted areas of bioscience that may soon be transferred from the laboratory into the clinical sphere. In this final paper Roblick and Auer consider the future role of the surgeon in the era of the "diagnostic chip".

DNA↗

PubMed2004

Protein expression patterns in primary carcinoma of the vagina.

Protein patterns in six samples from primary vaginal cancers, in five from normal vaginal tissue and in five primary cervical cancers, were analysed using two-dimensional polyacrylamide gel electrophoresis (2-DE). Protein expression profile was evaluated by computer-assisted image analysis (PDQUEST) and proteins were subsequently identified using matrix-assisted laser desorption/ionisation mass spectrometry. The aim was to analyse the protein expression profiles using the hierarchical clustering method in vaginal carcinoma and to compare them with the protein pattern in cervical carcinoma in order to find a helpful tool for correct classification and for increased biomedical knowledge. Protein expression data of a distinct set of 33 protein spots were differentially expressed. These differences were statistically significant (Mann-Whitney signed-Ranked Test, P<0.05) between normal tissue, vaginal and cervical cancer. Furthermore, protein profiles of pairs of primary vaginal and cervical cancers were found to be very similar. Some of the protein spots that have so far been identified include Tropomyosin 1, cytokeratin 5, 15 and 17, Apolipoprotein A1, Annexin V, Glutathione-S-transferase. Others are the stress-related proteins, calreticulin, HSP 27 and HSP 70. We conclude that cluster analysis of proteomics data allows accurate discrimination between normal vaginal mucosa, primary vaginal and primary cervical cancer. However, vaginal and cervical carcinomas also appear to be relatively homogeneous in their gene expression, indicating similar carcinogenic pathways. There might, further, be a possibility to identify tumour-specific markers among the proteins that are differentially expressed. The results from this study have to be confirmed by more comprehensive studies in the future.

Adenocarcinoma↗

PubMed2004

Sequential proteome alterations during genesis and progression of colon cancer.

Changes in the proteome of colon mucosal cells accompany the transition from normal mucosa via adenoma and invasive cancer to metastatic disease. Samples from 15 patients with sporadic sigmoid cancers were analyzed. Proteins were separated by two-dimensional gel electrophoresis. Relative differences in expression levels between normal tissue, adenoma, carcinoma and metastasis were evaluated in both intra- and inter-patient comparisons. Up- and down-regulated proteins (> twofold) during development to cancer or metastasis were excised and submitted to peptide mass fingerprinting and MS/MS sequence analysis, facilitated by the use of a compact disc workstation. In total, 112 protein spots were found to be differentially regulated, of which 72 were determined as to protein identity, 46 being up-regulated toward the progression of cancer, and 26 down-regulated. Several of the identifications correlate with proteins of the cell cycle, cytoskeleton or metabolic pathways. The pattern changes now identified have the potential for design of marker panels for assistance in diagnostics and therapeutic strategies in colorectal cancer.

Adenoma↗

PubMed2003

Gain of 17q in malignant fibrous histiocytoma is associated with a longer disease-free survival and a low risk of developing distant metastasis.

In this study, a panel of 39 primary malignant fibrous histiocytomas (MFH) of high malignancy grade were characterised for chromosomal alterations. The results were then evaluated in relation to the survival and the occurrence of recurrent disease during follow-up for an average period of 63 months. Chromosomal alterations detected by comparative genomic hybridisation (CGH) were recorded in 37 of the 39 cases analysed. The most frequent CGH abnormalities were gains of 17p, 20q, 16p, 17q, 1p31, 7q21, and 9cen-q22, and losses of 9p21-pter and 13q21-22. However, the patterns of CGH imbalances did not allow the identification of a single common event, suggesting that the key initiating event(s) is not a numerical imbalance. Patients with tumours harbouring a gain of 17q showed significantly longer overall and disease-free survival (P=0.001 and 0.008) as well as lower frequency of metastasis (P=0.018) during follow-up. Taken together, the findings suggest that the clinical outcome of MFH is associated with the genetic profiles of the primary tumours. Importantly, a subgroup of MFHs characterised by a low risk of developing metastasis and local recurrence is recognised based on their frequent gains of 17q by CGH.

Adult↗

PubMed2003

Laminin 5 gamma 2 chain expression: a marker of early invasiveness in colorectal adenomas.

AIM: Polyps of the colon and rectum are considered to be premalignant lesions in the development of colorectal cancer. However, knowledge of how normal epithelial cells gain invasive properties is limited. Laminin 5 gamma 2 chain expression was investigated to determine the role of laminin 5 as a marker of potential invasiveness in colorectal polyps. MATERIAL/METHODS: Sixty seven polyps of different types (15 hyperplastic polyps, 12 serrated adenomas, 16 tubular adenomas, and 24 adenomas with a villous component) were assessed for gamma 2 chain expression of laminin 5 by immunohistochemistry on archival, paraffin wax embedded sections. RESULTS: Ten polyps stained positive and the number of polyps expressing the laminin 5 gamma 2 chain increased significantly as the phenotype of the adenomas became more atypical: none of the 15 hyperplastic polyps, two of the 16 tubular adenomas (12.5%), and six of the 24 adenomas with a villous component (25%) were positive. Two of 12 (17%) serrated adenomas, regarded as a distinct form of colorectal neoplasia, showed gamma 2 chain expression. Furthermore, laminin 5 gamma 2 chain expression correlated with lesion size. Polyps smaller than 10 mm expressed the gamma 2 chain less frequently than did those equal to or larger than 10 mm. CONCLUSION: Laminin 5 gamma 2 chain expression was found to increase progressively towards a more atypical phenotype of adenoma. The results suggest that, in the future, laminin 5 gamma 2 chain expression may be used as an indicator of incipient malignant transformation of a benign colorectal adenoma.

Adenoma↗

PubMed2003

Laminin-5 gamma2-chain expression and DNA ploidy as predictors of prognosis in endometrial carcinoma.

Expression of the laminin-5 gamma2-chain in carcinoma cells has been implicated in tumor invasion. The aim was to investigate the expression and prognostic significance of the ln-5 gamma2-chain compared with clinicopathological factors and tumor cell DNA ploidy in endometrial carcinoma. Histological specimens from 80 endometrial carcinomas were examined with respect to immunohistochemical ln-5 gamma2-chain expression and correlated to the clinicopathological characteristics, DNA ploidy, and survival. Sixty-eight of 80 investigated cases were judged to be positive for the ln-5 gamma2-chain. Ln-5 gamma2-chain did not show any correlation to stage, histopathological subtype, grade, and DNA ploidy. In univariate analyses, advanced stage (p < 0.001), nonendometrioid carcinoma (p = 0.030), low grade (p < 0.001), aneuploid tumors (p < 0.001), and ln-5 gamma2-chain expression (p = 0.017) were highly associated with poor survival. Aneuploid tumors in combination with strong ln-5 gamma2-chain expression were significant predictors (p < 0.001) of poor prognosis. In multivariate analyses including stage, histopathological subgroup, grade, DNA ploidy, and ln-5 gamma2-chain expression, all lost their significant prognostic information except for stage (p < 0.001) and grade (p < 0.05). Ln-5 gamma2-chain expression and DNA ploidy both as a single parameter and in combination were demonstrated to be signifi- cant prognostic factors in univariate analysis. However, stage and grade provided more useful clinical information beyond histopathological subgroup, DNA ploidy, and ln-5 gamma2-chain expression. The results also indicate that ln-5 gamma2-chain expression is upregulated during the progression of endometrial carcinoma.

Cell Adhesion Molecules↗

PubMed2001

DNA content of granulocytes, monocytes, and lymphocytes in the bone marrow smears of patients with myelodysplastic syndromes.

Recently, we have reported a high incidence of DNA hypodiploidy defined as DNA index (DI) in blasts/promyelocytes from 39 patients with myelodysplastic syndromes (MDS) found to be without a relationship to cytogenetics. In the present study the DNA content (DI) in granulocytes, monocytes, and lymphocytes measured in the same bone marrow smears from the above patients are reported. DNA hypodiploidy was found in mature cells, not only in myeloid cells (granulocytes and monocytes) but also in lymphocytes. A lower mean DI in each cell type of patients compared to controls was found. Pairwise comparison of the mean DI (+/-SE) in 32 patients with normal (n = 22) and abnormal (n = 10) cytogenetics and controls (n = 8) showed a significantly (P < 0.01) lower value for each group of patients, respectively, in all cell types. No difference was found between the two groups of patients. Presence of weak-Feulgen stained nuclei (DI < 0.40) in granulocytes and monocytes was more pronounced in patients expressing DNA hypodiploid immature cell populations, but only occasionally in lymphocytes, suggesting a link to an apoptotic event and intramedullary cell death. DNA hypodiploidy is shown to be a common feature even in mature cell populations in MDS bone marrows. Clonality, by means of DNA content, appears reasonable as regards the granulocytes and monocytes. DNA hypodiploid lymphocytes, on the other hand, might be small blasts (stem cells) or dying cell populations of unknown origin.

Adolescent↗

PubMed2001

Identification of proteins in human prostate tumor material by two-dimensional gel electrophoresis and mass spectrometry.

Protein patterns in cells collected from benign prostatic tissues and prostate carcinomas were analyzed using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Polypeptide expression was evaluated by computer-assisted image analysis (PDQUEST). Proteins expressed by prostate tumors were identified via in-gel digestion and subsequent matrix-assisted laser desorption/ionization mass spectrometry. In addition to cytoskeletal and mitochondrial proteins, a 40-kDa protein was identified as prostatic acid phosphatase (PAP). PAP expression decreased approximately twofold between benign and malignant tissue. Increased expression of heat shock protein 70 and decreased expression of tropomyosin 1 were also observed in the malignant tissue. The analysis of prostate material by two-dimensional gel electrophoresis and mass spectrometry shows that particular proteins are of interest as markers of disease.

Acid Phosphatase↗

PubMed2001

Human papillomavirus infection, centrosome aberration, and genetic stability in cervical lesions.

DNA replication and centrosome duplication have to be strictly synchronized to guarantee genomic stability. p53, pRb, cyclin E, and cyclin A are reported to be involved in the synchronizing process. We investigated the relationship between papillomavirus infection, centrosome aberration and aneuploidy during genesis of cervical carcinoma. The number of centrosomes found in cells from normal cervical epithelium (n = 5), condyloma acuminata (n = 5), cervical intraepithelial neoplasia (CIN) I, II, and III (n = 14) and invasive cervical carcinoma (n = 5) was analyzed by gamma tubulin immunofluorescence staining. The nuclear DNA content was investigated by image cytometry and human papillomavirus (HPV) infection was determined by polymerase chain reaction. Normal epithelia and condyloma acuminata showed cells with one or two centrosomes, whereas CIN lesions showed cells with an increasing number of centrosomes. This abnormality was found to be lowest in CIN I lesions, increased with advancing grade of CIN and was highest in lesions of invasive carcinomas. In parallel, an increasing number of cells with aberrant DNA content was seen. All carcinomas and all except one of the CIN III lesions showed aneuploidy. Three CIN II cases were aneuploid and two cases with CIN I were tetraploid. Normal epithelia and condyloma acuminata showed diploidy. All invasive carcinomas and lesions with CIN were positive for high-risk HPV types 16, 18, or 31, except one invasive carcinoma and one CIN II lesion positive for universal primers only. Three condyloma acuminata were HPV 16-positive and one HPV 6-positive. The results suggest that high-risk HPV infection is correlated to a progressive numerical disturbance of centrosome replication followed by progressive chromosomal aberrations in CIN lesions and invasive carcinomas.

Adult↗

PubMed2001

[Interphase cytogenetics with DNA-probes for chromosome 8 to detect circulating tumor cells in breast cancer patients].

The detection of micrometastases in the bone marrow or peripheral blood of cancer patients is increasingly used for a more sensitive tumor staging and prognostication. The potential value of the currently used techniques for the detection of epithelial antigens by RT-PCR or immunohistochemistry in respect of specificity is currently controversially discussed. In the present study we demonstrate a new approach which enables the direct visualization of the tumor specific alteration of chromosome 8 in circulating tumor cells. We have therefore studied breast cancer patients with various tumor stages and tried to determine the frequency of circulating tumor cells in the peripheral blood by using interphase cytogenetics for chromosome 7 and 8. Imprints of primary breast cancers and cytospins with circulating tumor cells of corresponding patients were studied in a blinded fashion. The blood samples were generated by immunomagnetic enrichment of circulating tumor cells from peripheral blood by ferrofluid and centrifugation onto cover slips. These cytospins were then hybridized with centromer probes 7 and 8. After analyzing 27 patients with benign as well as malignant breast tumors we can demonstrate that the chromosomal pattern between malignant tumor and corresponding circulating tumor cells is identical. Furthermore, the detection of circulating tumor cells directly correlates with the primary tumor stage. We did not find any cells with chromosome 8 alterations in the patients with benign disease. Surprisingly, even in early breast cancers (T1N0) interphase cytogenetics identified circulating tumor cells in 2 out of 4 patients. In conclusion, interphase cytogenetics represent a non-invasive, sensitive and specific assay for the direct visualization of circulating tumor cells in the peripheral blood. The prognostic value of these findings remains to be further evaluated in larger prospective studies.

Breast Neoplasms↗

PubMed2001

Ulcerative colitis and colorectal carcinoma: DNA-profile, laminin-5 gamma2 chain and cyclin A expression as early markers for risk assessment.

BACKGROUND: Ulcerative colitis patients are at increased risk for developing colorectal carcinomas. Despite expensive surveillance programmes, clinical practice reflects an uncertainty in individual risk assessment. The aim of the study was to evaluate independent cellular features with possible predictive value. METHODS: Two patient groups were selected: group A comprised 8 patients with ulcerative colitis-associated colorectal carcinomas, group B comprised 16 ulcerative colitis patients with risk factors (duration of disease, extent of inflammation, epithelial dysplasias). A total of 683 paraffin-embedded mucosal biopsies were retrospectively evaluated for inflammatory activity, grade of dysplasia, ploidy status, laminin-5 gamma2 chain and cyclin A expression. RESULTS: Mild or moderate inflammatory activity was present in 78% of all biopsies, low- or high-grade dysplasia in 5.5%. There was no difference in inflammatory activity and dysplasia between patient groups. In group A, 75% of the biopsies exhibited aneuploid DNA distribution patterns. Group B showed mainly proliferative-diploid cell populations (85% / P = 0.006). Laminin-5 gamma2 chain was expressed in 13% of all biopsies, with a higher frequency in group A (P = 0.002). Cyclin A expression was found in 98% of all biopsies, with a higher number of immunopositive cells in group A biopsies (P = 0.014). CONCLUSIONS: Combined nuclear DNA assessment, laminin-5 gamma2 chain and cyclin A expression may help to identify ulcerative colitis patients with an increased risk for cancer development.

Adult↗

PubMed2001

Genetic instability promotes the acquisition of chromosomal imbalances in T1b and T1c breast adenocarcinomas.

In order to evaluate biological and genetic properties of early breast carcinomas we analyzed microdissected tissue from 33 primary breast carcinomas stage T1b and T1c with respect to the nuclear DNA content, the expression pattern of Ki-67, cyclin A, p27KIP1, p53 and p21WAF1, and chromosomal gains and losses. The results show that T1b carcinomas (6-10 mm, n=17) were frequently near-diploid (53%) with low proliferative activity and staining patterns of p53 and p21WAF1 that suggest the presence of wild type protein. The majority (12/16) of the T1c tumors (11-20 mm), however, was aneuploid, and proliferative activity and p53 expression were increased. Larger tumor size correlated with an increasing number of chromosomal copy number changes and in particular with regional amplifications. High level copy number increases (amplifications), however, were found exclusively in the aneuploid tumors. Amplification events correlated with elevated cyclin A and reduced p27 expression, respectively. Our results suggest that the sequential acquisition of genomic imbalances during tumor progression is accelerated in aneuploid tumors, and may contribute to the increased malignancy potential.

Adenocarcinoma↗

PubMed2001

Laminin-5 gamma 2 chain expression correlates with unfavorable prognosis in colon carcinomas.

Expression of the gamma 2 chain at the invasive front of different tumors has indicated an important role for laminin-5 in cell migration during tumor invasion and tissue remodeling. As there is considerable need for reliable invasion and prognostic markers we evaluated the correlation of laminin-5 gamma 2 chain expression with clinicopathologic parameters and patient survival in 93 primary colon carcinomas. Epithelial cells of normal mucosa were consistently negative for staining. In contrast, positive cytoplasmic staining was observed in 89 tumors (96%). Twenty-four (26%) cases were scored as sparse, 34 (37%) as moderate, and 31 (33%) as frequent gamma 2 chain expression. There was a significant association of laminin-5 gamma 2 chain expression and local invasiveness of colon carcinomas according to Dukes stage (A-C) (p=0.001) and tumor budding (p<0.001). A statistical significance could also be noted in decreasing tumor differentiation (p<0.001) and correlation to tumor size (p=0.032). No correlation was observed to tumor site. Univariate analysis identified laminin-5 (p=0.010), tumor differentiation (p=0.006) and Dukes grade (p<0.001) as significant variables in predicting prognosis. However, by multivariate analyses, this study could not demonstrate that laminin-5 gamma 2 chain expression is an independent predictive factor for survival. The results indicate that laminin-5 gamma 2 chain expression is up-regulated during the progression of human colon cancer and that it plays a role in the aggressiveness of these tumors. Demonstration of laminin-5 gamma 2 chain positivity also facilitates detection of individual cells or minor cell clusters invading the surrounding stroma. Figures on http://www.esacp.org/acp/2001/22-4/lenander.htm.

Adenocarcinoma↗

PubMed2000

Reliability of DNA cytometric S-phase analysis in surgical biopsies: assessment of systematic and sampling errors and comparison between results obtained by image and flow cytometry.

Three major parameters in DNA histograms that contribute to the reliability of S-phase analysis were evaluated. These parameters are (1) the extent of background in relation to the amount of S-phase cells (and the validity of its subtraction), (2) the size of the "free" S-phase range (S(free)), and (3) the sampling error of cell counting. Tests in histograms obtained from surgical biopsies by flow cytometry (FCM) showed that the background subtraction is reliable if the found S-phase fraction is higher than the fraction of background events in the histogram range of the cell population. The size of S(free) was determined in computer-generated test histograms as a function of variables such as the coefficient of variation (CV) and the DNA index (DI). To calculate the sampling error of cell counting above background and in S(free), a model was developed that was validated by experimental data. This error can serve as an indicator of the uncertainty in S-phase analysis. The poor correlation found between %S values measured by image cytometry (ICM) and FCM in surgical biopsies was assigned to high uncertainty by low cell numbers in ICM histograms. A method is proposed to estimate quantitatively the reliability of S-phase analysis that can facilitate the interpretation of results.

Biopsy↗

PubMed2000

Classification of human ovarian tumors using multivariate data analysis of polypeptide expression patterns.

Large amounts of data on quantitative gene expression are generated by procedures such as 2-DE analysis of proteins or cDNA microarrays. Quantitative molecular variation may potentially be used for the development of methods for the classification of tumors. We used here the statistical concepts of principal components analysis (PCA) and partial least square analysis (PLS) in an attempt to type ovarian tumors. Using a set of 170 polypeptides, 22 tumors were used to establish a model ("learning set") for classification into 3 groups (benign/borderline/malignant). Eighteen tumors were then used to test the model. Six of 8 carcinomas and 3 of 4 borderline tumors were correctly classified. Two of 6 benign lesions were correctly classified, 3 were classified as borderline and 1 as carcinoma. We conclude that it may be possible to classify tumors according to their constitutive protein expression profile using multivariate analysis, thus making classification by artificial intelligence a future possibility.

Breast Neoplasms↗