Biomedical subjects

Christian Pilarsky

Publications and source records attributed to Christian Pilarsky.

30 records · Page 2Linked to original sources

PubMed2003

Gene expression profiles of microdissected pancreatic ductal adenocarcinoma.

In a search for new molecular markers of pancreatic ductal adenocarcinoma (PDAC), we compared the gene expression profiles of seven pancreatic carcinomas and one carcinoma of the papilla Vateri with those of duct cells from three non-neoplastic pancreatic tissues. In addition, the human pancreatic duct cell line and five PDAC cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2, HPAF) were examined. RNA was extracted from microdissected tissue or cultured cell lines and analysed using a custom-made Affymetrix Chip containing 3023 genes, of which 1000 were known to be tumour associated. Hierarchical clustering revealed 81 differentially expressed genes. Of all the genes, 26 were downregulated in PDAC and 14 were upregulated in PDAC. In PDAC cell lines versus normal pancreatic duct cells, 21 genes were downregulated and 20 were upregulated. Of these 81 differentially expressed genes, 15 represented human genes previously implicated in the tumourigenesis of PDAC. From the genes that were so far not known to be associated with PDAC tumorigenesis, we selected ADAM9 for further validation because of its distinct overexpression in tumour tissue. Using immunohistochemistry, the over-expressed gene, ADAM9, was present in 70% of the PDACs analysed. In conclusion, using microarray technology we were able to identify a set of genes whose aberrant expression was associated with PDAC and may be used to target the disease.

Adenocarcinoma↗

PubMed2003

Prospective evaluation of ultrasound and colour duplex imaging for the assessment of surgical resectability of pancreatic tumours.

BACKGROUND: This study was performed to evaluate colour duplex imaging (CDI) for the assessment of resectability of pancreatic tumours (PTs). METHOD: From October 1998 to December 2001, 182 patients consecutively having surgery for a PT were enrolled in this prospective study. Extension of the tumour to large blood vessels and retroperitoneum, the detection of liver metastases, enlarged lymph nodes and peritoneal carcinomatosis were defined as criteria for assessment. The patients were grouped into three classes of resectability: US-TU 1 = resectable/potentially curable, US-TU 2 = questionably resectable/curable, and US-TU 3 = non-resectable/not curable. CDI was performed by five different examiners. Results were compared with intra-operative findings. RESULTS: Using CDI, we classified 85 (46.7%) tumours as resectable, 64 (35.2%) as non-resectable, and 33 (18.1%) as questionably resectable. Overall, 46.2% ( n=84) were found to be resectable, and 53.8% ( n=98) to be non-resectable, intra-operatively. A correlation between CDI classification and intra-operative findings was found in 138 of 149 cases (92.6%) (sensitivity 88.4%, specificity 96.3%). With regard to the complete oncological status (local extension, metastases, lymph-node staging and peritoneal carcinomatosis), a sensitivity of 77.2% and specificity of 95.7% were found. Non-correlated findings were likely attributed to missing small liver metastases, peritoneal carcinomatosis without ascites, and on difficulties in the assessment of enlarged lymph nodes concerning tumour infiltration. CONCLUSION: The use of CDI in evaluation of PTs may provide valuable pre-operative assessment of surgical resectability and may be performed in the clinical setting.

Adenocarcinoma↗

PubMed2003

ALCAM/CD166 is up-regulated in low-grade prostate cancer and progressively lost in high-grade lesions.

BACKGROUND: Activated leukocyte cell adhesion molecule (ALCAM, CD166) is expressed in various tissues, including malignant melanoma, prostate cancer cell lines, and prostate cancer. We aimed to clarify the expression patterns of ALCAM in normal and malignant prostate tissue. METHODS: RNA from 54 matched pairs of microdissected prostate tissue (tumor and normal) was hybridized to a custom built 4K GeneChip. Frozen section immunohistochemistry was used to confirm the ALCAM expression. RESULTS: Chip-based transcript analysis revealed an up-regulation of ALCAM in prostate cancer in 22% of cases. Immunohistochemistry showed a focally raised ALCAM expression in 81% and a decreased expression in 19% of cases. These expression patterns correlated significantly with Gleason tumor grade: ALCAM up-regulation was found in most low-grade tumors (Gleason grade 1-3), whereas down-regulation occurred preferentially in high-grade tumors (Gleason grade 4 and 5), although up-regulation of ALCAM expression was preserved in two Gleason grade 5 tumors. CONCLUSION: ALCAM expression is commonly disturbed in prostate cancer, which might indicate a role of ALCAM in the progression of this disease.

Activated-Leukocyte Cell Adhesion Molecule↗

PubMed2003

Identification of candidate tumor-suppressor genes in 6q27 by combined deletion mapping and electronic expression profiling in lymphoid neoplasms.

Deletions in the long arm of chromosome 6 (6q) are among the most frequent chromosome aberrations in lymphoid neoplasms. Recently, the region of minimal deletion (RMD1) in 6q27 was narrowed down to 5-9 Mb. In the present study, we aimed to define the distal border of the commonly lost region in 6q27 more precisely and to identify and investigate tumor-suppressor genes (TSGs) from this region. Twenty-nine cases, in which our previous fluorescence in situ hybridization (FISH) screening that used a set of 36 YAC probes revealed loss in 6q25-27, were further investigated by means of FISH. In all cases, deletions of 6q27 extended from yeast artificial chromosome (YAC) 977e10 spanning the proximal border of RMD1 to the most telomeric YAC 933f7 within the recently established YAC-contig of this region. An interstitial homozygous deletion, flanked by the telomeric probe TelVysion6q and YAC 971g12, was detected, which substantially narrows down the RMD1. To identify candidate TSGs down-regulated in malignant lymphomas from this region of homozygous loss, we performed electronic profiling of expressed sequences mapped to this region. This analysis suggested the gene PDCD2 originally thought to be involved in programmed cell death to be probably down-regulated in malignant B-cell lymphomas compared to normal B lymphocytes. Nevertheless, mutation analyses failed to identify mutations in the coding region of PDCD2 in nine lymphomas with FISH-proved 6q27 deletions. Furthermore, epigenetic studies in these nine and an additional 48 lymphomas did not show altered methylation of the PDCD2 locus in these tumors. Possibly haploinsufficiency is effectual in accelerating tumor progression.

Cell Line, Transformed↗

PubMed2003

WIF1, a component of the Wnt pathway, is down-regulated in prostate, breast, lung, and bladder cancer.

To detect novel Wnt-pathway genes involved in tumourigenesis, this study analysed the RNA expression levels of 40 genes of the Wnt pathway by chip hybridization of microdissected matched pairs of 54 primary prostate carcinomas. Eleven genes showed greater than two-fold differential expression in at least 10% of prostate cancers. Three of these genes encode extracellular components of the Wnt pathway (WNT2, WIF1, SFRP4); two are receptors (FZD4, FZD6); two belong to the intracellular signal cascade (DVL1, PPP2CB); one regulates transcription (TCF4); and three represent genes regulated by this pathway (CCND2, CD44, MYC). While SFRP4, FZD4, FZD6, DVL1, TCF4, and MYC are up-regulated, WIF1, WNT2, PPP2CB, CCND2, and CD44 are down-regulated in certain prostate cancer patients. Wnt inhibitory factor 1 (WIF1) and secreted frizzled related protein (SFRP4) showed the most significant aberrant expression at the RNA level. WIF1 was down-regulated in 64% of primary prostate cancers, while SFRP4 was up-regulated in 81% of the patients. Immunohistochemical analysis using a polyclonal antibody revealed strong cytoplasmic perinuclear WIF1 expression in normal epithelial cells of the prostate, breast, lung, and urinary bladder. Strong reduction of WIF1 protein expression was found in 23% of prostate carcinomas, but also in 60% of breast, 75% of non-small cell lung (NSCLC), and 26% of bladder cancers analysed. No significant association between WIF1 down-regulation and tumour stage or grade was observed for prostate, breast or non-small cell lung carcinomas, indicating that loss of WIF1 expression may be an early event in tumourigenesis in these tissues. However, down-regulation of WIF1 correlated with higher tumour stage in urinary bladder tumours (pTa versus pT1-pT4; p = 0.038).

Adaptor Proteins, Signal Transducing↗

PubMed2003

Systematic isolation of genes differentially expressed in normal and cancerous tissue of the pancreas.

BACKGROUND: There is increasing knowledge about the genetic basis of pancreatic cancer (PaCa). Tumor suppressor genes (TSGs; e.g. p53 and DPC4) and oncogenes (e.g. K-ras) have been shown to be involved in the development of PaCa. However, the extent of chromosomal changes (gains and losses) implicates that many more genes may be involved in the multistep progression of PaCa. Identification of these genes is essential for understanding the molecular events in the development of PaCa. METHODS: We assembled public and proprietary libraries of more than 4 million expressed sequence tags using newly developed software tools. RESULTS: We identified a total of 249 genes with specific expression patterns in normal and cancerous tissue of the pancreas. Of these, 27 genes were found to be preferentially expressed in normal tissue of the pancreas, while 222 genes showed significant upregulation of expression in PaCa. Of the 249 genes, 232 (93.2%) were found to represent known human genes or putative human homologues of genes characterized previously in other species, while 17 (6.8%) represent putative new genes. CONCLUSION: These genes may represent a valuable source to identify novel TSGs and oncogenes involved in the carcinogenesis of PaCa.

DNA, Complementary↗

PubMed2002

CD24 is expressed in ovarian cancer and is a new independent prognostic marker of patient survival.

CD24 is a small heavily glycosylated glycosylphosphatidylinositol-linked cell surface protein, which is expressed in hematological malignancies as well as in a large variety of solid tumors. Very recently its expression in ovarian cancer has been found on RNA level by chip analysis. We evaluated CD24 protein expression by immunohistochemistry in 9 normal ovaries and 69 epithelial ovarian tumors (5 adenomas, 8 borderline tumors, and 56 carcinomas) with known follow-up data. Surface epithelium of normal ovaries as well as adenomas did not express CD24. In borderline tumors CD24 was expressed in membrane in 75% of cases, whereas cytoplasmic expression was detected in only one of nine cases. In invasive ovarian carcinomas, a membranous expression was detected in 84% and a cytoplasmic expression in 59% of cases. In univariate survival analysis of all invasive ovarian carcinomas, a highly significant association of increased cytoplasmic CD24 expression with shortened patient survival (mean 98 months versus 37 months, P = 0.0002, log rank test) was demonstrated. Other significant prognostic parameters were International Federation of Gynecology and Obstetrics (FIGO) stage, Silverberg grade, patient age, undifferentiated histological type, and metastatic disease. We did not detect a significant correlation of CD24 with these clinicopathological parameters. In multivariate analysis, only CD24 and FIGO stage were independent prognostic parameters. Our data suggest that the expression of CD24 as detected by immunohistochemistry is a new independent molecular marker for shortened survival time of patients with epithelial ovarian carcinomas.

Adenoma↗

PubMed2002

No evidence for involvement of beta-catenin and APC in urothelial carcinomas.

The wnt pathway plays an important role in embryonal patterning and cell fate determination, involving stabilization of nuclear and cytoplasmic beta-catenin (CTNNB1) mediated by APC, axin, and other proteins. Uncomplexed beta-catenin binds to TCF/LEF transcription factors and activates the expression of growth regulatory target genes such as c-myc or cyclin D1. In colorectal and other cancers, constitutive wnt signaling results frequently from mutations in one or more pathway components, e.g. APC and beta-catenin, resulting in nuclear and/or cytoplasmic accumulation of beta-catenin. In the present study, the most frequent alterations in the CTNNB1 and APC genes were investigated in primary urothelial bladder tumors and cell lines. Snap-frozen bladder tumors (n=99) of different stages and grades and 4 cell lines (RT4, RT112, J82, UROtsa) were investigated for APC allelic deletions by loss of heterozygosity (LOH) analysis. The most frequent mutated regions of CTNNB1 (degradation box in the third exon) and APC (mutation cluster region) were directly sequenced. Beta-catenin expression was analyzed by immunofluorescence in the cell lines. LOH at the APC gene locus on chromosome 5q21 was found in 7 of 72 (10%) of the informative cases. No mutations were found in either CTNNB1 or APC. A previously described polymorphism at codon 1493 of the APC gene was detected in 8 tumors and 3 cell lines. All cell lines showed normal membranous beta-catenin staining without evidence for nuclear or cytoplasmic accumulation. Alteration of APC and beta-catenin, which are the most frequent wnt pathway alterations in many tumor types, are rare events in urothelial carcinomas. Other wnt pathway members, such as axin, may play an important role in urothelial carcinogenesis.

Adenomatous Polyposis Coli Protein↗

PubMedDate not supplied

Identification and validation of commonly overexpressed genes in solid tumors by comparison of microarray data.

Cancers originating from epithelial cells are the most common malignancies. No common expression profile of solid tumors compared to normal tissues has been described so far. Therefore we were interested if genes differentially expressed in the majority of carcinomas could be identified using bioinformatic methods. Complete data sets were downloaded for carcinomas of the prostate, breast, lung, ovary, colon, pancreas, stomach, bladder, liver, and kidney, and were subjected to an expression analysis using SAM. In each experiment, a gene was scored as differentially expressed if the q value was below 25%. Probe identifiers were unified by comparing the respective probe sequences to the Unigene build 155 using BlastN. To obtain differentially expressed genes within the set of analyzed carcinomas, the number of experiments in which differential expression was observed was counted. Differential expression was assigned to genes if they were differentially expressed in at least eight experiments of tumors from different origin. The identified candidate genes ADRM1, EBNA1BP2, FDPS, FOXM1, H2AFX, HDAC3, IRAK1, and YY1 were subjected to further validation. Using this comparative approach, 100 genes were identified as upregulated and 21 genes as downregulated in the carcinomas.

Female↗

PubMedDate not supplied

Gene expression profiling of microdissected pancreatic ductal carcinomas using high-density DNA microarrays.

Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of malignancy-related death and is the eighth most common cancer with the lowest overall 5-year relative survival rate. To identify new molecular markers and candidates for new therapeutic regimens, we investigated the gene expression profile of microdissected cells from 11 normal pancreatic ducts, 14 samples of PDAC, and 4 well-characterized pancreatic cancer cell lines using the Affymetrix U133 GeneChip set. RNA was extracted from microdissected samples and cell lines, amplified, and labeled using a repetitive in vitro transcription protocol. Differentially expressed genes were identified using the significance analysis of microarrays program. We found 616 differentially expressed genes. Within these, 140 were also identified in PDAC by others, such as Galectin-1, Galectin-3, and MT-SP2. We validated the differential expression of several genes (e.g., CENPF, MCM2, MCM7, RAMP, IRAK1, and PTTG1) in PDAC by immunohistochemistry and reverse transcription polymerase chain reaction. We present a whole genome expression study of microdissected tissues from PDAC, from microdissected normal ductal pancreatic cells and pancreatic cancer cell lines using high-density microarrays. Within the panel of genes, we identified novel differentially expressed genes, which have not been associated with the pathogenesis of PDAC before.

Aged↗

PubMedDate not supplied

Biological and molecular characterization of a new human ampullary cancer cell line.

BACKGROUND: Ampullary carcinoma of the pancreas accounts for 5% of all gastrointestinal malignancies in humans. Only a very few cell lines of this carcinoma have been established. PATIENTS AND METHODS: Tumor cells isolated from a surgically resected ampullary carcinoma were put into culture. The cultured cells were characterized for their biological, immunological and molecular properties including in vitra and in viva cell kinetics, karyotype, expression of tumor markers and lysis by autologous cytotoxic T-lymphocytes. RESULTS: An ampullary cancer cell line, designated UKEAC-99, was established. It proliferates as a monolayer with a doubling-time of 29 hours. The cytological features of the cultured and of the xenografted cells from SCID mice were similar to those of the primary tumor. UKEAC-99 cells were lysed by autologous cytotoxic T-lymphocytes in a HLA-class I restricted fashion. Hybridization of tumor mRNA to a dedicated DNA-chip revealed overexpression of several genes involved in tumor progression such as L6, Matrilysin and Vimentin. Tumor suppressor genes and apoptosis-associated genes like p73 or IL1 alpha are expressed at a low level. CONCLUSION: We established a new ampullary carcinoma cell line, which is rare and may contribute to our understanding of the biological behavior of ampullary carcinoma. The lysis by autologous cytotoxic T-lymphocytes and possibly shared antigens with other pancreatic cancers may help to identify tumor-associated/tumor-specific antigens. The detailed analysis of gene expression allows researchers new insights into ampullary cancer that can be exploited in future in vitro and in vivo models.

Ampulla of Vater↗

PubMedDate not supplied

Retroperitoneal soft tissue sarcomas: prognosis and treatment of primary and recurrent disease in 117 patients.

BACKGROUND: The objective of this study was to define prognostic factors for patients with primary soft tissue sarcomas (STS) arising from the retroperitoneum. PATIENTS AND METHODS: One hundred and seventeen consecutive patients, resected in our institutions between July 1972 and November 2002, were reviewed. RESULTS: The prognostic factors predicting survival were incomplete resection, a tumor of high grade (G3), metastases to lymph nodes and distant metastasis. Patients with a malignant fibrous histiocytoma (MFH) or a malignant peripheral nerve sheath tumor (MPNST) had a worse prognosis than those patients with other tumors. The prognostic factors predicting local recurrence were incomplete resection and high grade (G3). The prognostic factors predicting metastasis were incomplete resection, lymph node metastasis at the time of the resection of the primary tumor and tumor histology. CONCLUSION: Since only complete tumor resection offers a chance for cure, it is mandatory, and local control remains the most significant challenge in the management of retroperitoneal sarcomas. Other therapies can support surgical treatment, depending on the tumor localization and histological entity. The management of patients with a STS should be provided by a specialized team of surgeons, oncologists and radiotherapists, and patients should be enrolled in a treatment study whenever possible.

Chemotherapy, Adjuvant↗