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W N Dinjens

Publications and source records attributed to W N Dinjens.

At least 19 recordsLinked to original sources
PubMed2001

Molecular genetic analysis of the von Hippel-Lindau and human peroxisome proliferator-activated receptor gamma tumor-suppressor genes in adenocarcinomas of the gastroesophageal junction.

We investigated whether 2 candidate tumor-suppressor genes, VHL at 3p25-26 and PPAR gamma at 3p24.2-25, are involved in GEJ adenocarcinogenesis. In 43 GEJ tumor samples from 40 patients, the entire coding sequence of the VHL gene and the 5' and part of the 3' UTR as well as exons 3 and 5 of the PPAR gamma gene were screened by PCR-SSCP analysis. LOH at 3p25-26 was analyzed with 2 polymorphic microsatellite markers and with the VHL exon 1 and intron 2 polymorphisms. The relationship between LOH and clinicopathologic parameters was assessed. Expression of VHL was investigated by immunohistochemistry with a VHL-specific antibody. PCR-SSCP analysis of VHL revealed 2 different aberrant patterns in 19 patients. Upon DNA sequencing, 1 pattern appeared to be a previously described exon 1 polymorphism. The other single aberrant pattern was an intron 2 polymorphism, not yet described. PCR-SSCP analysis of PPAR gamma showed no aberrant migration patterns. LOH analysis revealed 3p25-26 loss in 24/36 (67%) informative cases, but this was not significantly correlated with clinicopathologic parameters. By immunohistochemistry, all tumors showed expression of VHL protein. Despite the very frequent LOH of 3p in GEJ adenocarcinomas, mutations in VHL and PPAR gamma were not detected. Mutations outside the screened sequences, a gene dosage effect or involvement of another tumor-suppressor gene on 3p as the target of LOH should be considered.

Adenocarcinoma↗
PubMed2001

Establishment of cell lines from adenocarcinomas of the esophagus and gastric cardia growing in vivo and in vitro.

The aim of this study was to establish cell lines of adenocarcinomas of the gastro-esophageal junction(GEJ), which grow in vivo and in vitro. Primary esophageal and gastric cardia adenocarcinomas and corresponding lymph node metastases were xenografted subcutaneously to immunodeficient nude mice. In addition, tumor tissue was also used for in vitro culture. Xenografting of 70 primary adenocarcinomas and 17 metastases resulted in the initial growth of 22 and 6 tumors, respectively (total 32%). Upon retransplantation, six long-term xenografts [esophageal adenocarcinoma (OAC)P33X, OACP47X, OACP56X, OACP58X, OACP67X, OACP76X] from primary tumors and three (OACM2.1X, OACM30X, OACM53X) from metastases were obtained. In vitro culture attempts of 34 primary tumors and nine metastases resulted in the establishment of three (7%) permanent in vitro growing cell lines. From one patient, a cell line from the primary tumor (OACP4 C) and from a lymph node metastasis (OACM4.1 C) was established. The third cell line (OACM5.1 C) was also derived from a lymph node metastasis. The in vivo and in vitro cell lines were characterized using immunocytochemistry and microsatellite analysis to verify their epithelial and human tumor origin, respectively.

Adenocarcinoma↗
PubMed2001

Differential loss of chromosome 11q in familial and sporadic parasympathetic paragangliomas detected by comparative genomic hybridization.

Parasympathetic paragangliomas (PGLs) represent neuroendocrine tumors arising from chief cells in branchiomeric and intravagal paraganglia, which share several histological features with their sympathetic counterpart sympathoadrenal paragangliomas. In recent years, genetic analyses of the familial form of PGL have attracted considerable interest. However, the majority of paragangliomas occurs sporadically and it remains to be determined whether the pathogenesis of sporadic paraganglioma resembles that of the familial form. Furthermore, data on comparative genetic aberrations are scarce. To provide fundamental cytogenetic data on sporadic and hereditary PGLs, we performed comparative genomic hybridization using directly fluorochrome-conjugated DNA extracted from 12 frozen and 4 paraffin-embedded tumors. The comparative genomic hybridization data were extended by loss of heterozygosity analysis of chromosome 11q. DNA copy number changes were found in 10 (63%) of 16 tumors. The most frequent chromosomal imbalance involved loss of chromosome 11. Six of seven familial tumors and two of nine sporadic tumors showed loss of 11q (86% versus 22%, P = 0.012). Deletions of 11p and 5p were found in two of nine sporadic tumors. We conclude that overall DNA copy number changes are infrequent in PGLs compared to sympathetic paragangliomas and that loss of chromosome 11 may be an important event in their tumorigenesis, particularly in familial paragangliomas.

Adult↗
PubMed2001

Evaluation of oncogene amplification in intact and truncated cell nuclei of gastro-esophageal cancer cell lines by DNA in situ hybridisation.

Adenocarcinoma arising around the gastro-esophageal junction (GEJ) is a highly malignant form of cancer. Its incidence is rising sharply. The study of oncogenes in these carcinomas may give information concerning treatment and prognosis. In the present study, the fluorescence in situ hybridisation (FISH) technique was optimised for genetic characterisation of oncogenes in archival cancer specimens. Three cell lines derived from GEJ adenocarcinomas were investigated, i.e. JROECL 19, JROECL 33 and OACM5.1C, both in fresh and paraffin-embedded preparations. Furthermore, paraffin-embedded material of three xenografts was studied, i.e. JROECL 19, JROECL 33, and OACM4.1X. We focussed on the oncogenes MYC and HER2/neu, since they are frequently involved in intestinal cancers. Firstly, our results indicate that it is feasible to detect oncogene-specific probes with the FISH technique in formalin-fixed, paraffin-embedded material. Secondly, it appeared that the optimal section thickness for analysis was 2 microm. This thickness resulted in minimal nuclear overlap, which facilitates counting of FISH spots. Due to the truncation phenomenon, however, the sensitivity of the technique is less than FISH on intact nuclei. Importantly, (high level) oncogene amplifications were easily recognised in 2 microm thick sections. Finally, counting of the individual copy number of the MYC and HER2/neu oncogenes was feasible enabling an arbitrary assessment of low- and high-level amplification. In conclusion, FISH is an accurate technique for detecting amplification of oncogenes in paraffin-embedded patient material.

Adenocarcinoma↗
PubMed2001

Molecular biology of Barrett's adenocarcinoma.

OBJECTIVE: To review the current knowledge on the genetic alterations involved in the development and progression of Barrett's esophagus-associated neoplastic lesions. SUMMARY BACKGROUND DATA: Barrett's esophagus (BE) is a premalignant condition in which the normal squamous epithelium of the esophagus is replaced by metaplastic columnar epithelium. BE predisposes patients to the development of esophageal adenocarcinoma. Endoscopic surveillance can detect esophageal adenocarcinomas when they are early and curable, but most of the adenocarcinomas are detected at an advanced stage. Despite advances in multimodal therapy, the prognosis for invasive esophageal adenocarcinoma is poor. A better understanding of the molecular evolution of the Barrett's metaplasia to dysplasia to adenocarcinoma sequence may allow improved diagnosis, therapy, and prognosis. METHODS: The authors reviewed data from the published literature to address what is known about the molecular changes thought to be important in the pathogenesis of BE-associated neoplastic lesions. RESULTS: The progression of Barrett's metaplasia to adenocarcinoma is associated with several changes in gene structure, gene expression, and protein structure. Some of the molecular alterations already showed promise as markers for early cancer detection or prognostication. Among these, alterations in the p53 and p16 genes and cell cycle abnormalities or aneuploidy appear to be the most important and well-characterized molecular changes. However, the exact sequence of events is not known, and probably multiple molecular pathways interact and are involved in the progression of BE to adenocarcinoma. CONCLUSIONS: Further research into the molecular biology of BE-associated adenocarcinoma will enhance our understanding of the genetic events critical for the initiation and progression of Barrett's adenocarcinoma, leading to more effective surveillance and treatment.

Adenocarcinoma↗
PubMed2000

Genetic alterations involving exon 3 of the beta-catenin gene do not play a role in adenocarcinomas of the esophagus.

Beta-catenin has been identified as an oncogene. Phosphorylation of sites encoded by exon 3 of the beta-catenin gene facilitates degradation of this protein by the adenomatous polyposis coli (apc) gene product. Mutations in these sites or inactivation of apc lead to stabilization of beta-catenin, which then translocates to the nucleus where it modulates the transcription of genes involved in tumor formation. To explore the role of beta-catenin mutations in adenocarcinomas of the esophagus, we screened for genetic alterations in exon 3 in 69 tumor samples. We detected no mutations in exon 3 by PCR-SSCP analysis nor did we find large interstitial deletions involving exon 3. beta-catenin immunostaining on 54 tumors showed focal nuclear staining in 7 tumors and homogeneous nuclear staining in 3 tumors; in the latter; no mutations in the mutation cluster region of apc were detected. These results show that genetic alterations of exon 3 of the beta-catenin gene do not occur and therefore do not contribute to the pathogenesis of esophageal adenocarcinomas. The abnormal cytoplasmic and nuclear localization of beta-catenin indicates that other mechanisms leading to elevated free beta-catenin in these cancers must be involved.

Adenocarcinoma↗
PubMed2000

E-cadherin promotes intraepithelial expansion of bladder carcinoma cells in an in vitro model of carcinoma in situ.

High-grade transitional cell carcinomas (TCCs) of the urinary bladder are frequently associated with carcinoma in situ, which may replace large areas of the mucosa of the urinary tract. The invasive component of TCCs often reveals a loss of expression of the cell-cell adhesion molecule E-cadherin, but the role of E-cadherin in the development and expansion of intraepithelial neoplasia is unknown. To study the underlying mechanism of intraepithelial expansion (IEE), we have developed an IEE assay. Human TCC cell lines were investigated in this IEE assay for their capacity to replace the surrounding normal murine urothelial cells. In vitro IEE appeared to be prominent in three (SD, RT112, and 1207) of the four E-cadherin-positive cell lines. Although the two E-cadherin-negative cell lines (T24 and J82) were able to penetrate surrounding normal urothelium as single cells, they largely lacked the capacity of IEE. These results prompted us to investigate whether the cell-cell adhesion molecule E-cadherin is an important determinant for IEE. T24 cells that were transfected with full-length mouse E-cadherin cDNA displayed an enhanced IEE rate. Transfection did not influence their proliferative capacity, their pattern and level of integrin expression, or their ability to expand in the absence of surrounding urothelium. The data suggest that E-cadherin-mediated cohesiveness is an important factor in the IEE of bladder carcinoma cells. These observations argue for a dual, paradoxical role of E-cadherin in bladder tumorigenesis. On the one hand, E-cadherin promotes the expansion of intraepithelial neoplasia; on the other hand, its loss correlates with invasive behavior.

Animals↗
PubMed2000

Proliferative index in phaeochromocytomas: does it predict the occurrence of metastases?

Evaluation of the malignant potential of phaeochromocytomas in the absence of metastases presents a formidable challenge to both clinicians and pathologists. Until now, no widely accepted clinical, histological, immunohistochemical or molecular method has become available to discriminate malignant from benign phaeochromocytomas. In other endocrine tumours, estimation of proliferative activity by MIB-1 immunostaining has emerged as a promising approach for the determination of metastatic potential. In this study, the utility of MIB-1 immunostaining as a predictive marker for the occurrence of metastases in phaeochromocytomas was evaluated. In addition, the density of S100-positive sustentacular cells was studied, since their depletion has been identified as a negative predictive marker in smaller series. Furthermore, several clinicopathological parameters were evaluated. One hundred and ten patients operated on for a total of 99 benign and 37 malignant phaeochromocytomas were studied. All malignant tumours had documented metastases. The histopathological diagnosis of primary tumours and metastases was reviewed and graded for angioinvasion, capsular extension, and intra-tumoural necrosis. The proliferative index (percentage of MIB-1-positive cells) and the density of S100-positive cells were assessed. In addition, age at resection, associated familial tumour syndromes, tumour size, and tumour location were recorded. Univariate analysis revealed statistically significant correlations between malignancy and proliferative index (p<0.0005) and depletion of S100-positive sustentacular cells (p<0.0005). Fifty per cent of the malignant, but none of the benign phaeochromocytomas had a proliferative index greater than 2.5%. Higher age at resection (p=0. 03), sporadic occurrence (p<0.0005), extra-adrenal location (p<0. 0005), tumour size (p<0.0005), and necrosis (p=0.03) were also significantly associated with malignancy. Logistic regression showed that proliferative index (p=0.0072), size (p=0.0022), and extra-adrenal location (p=0.0012) of the primary tumour were independently predictive for malignancy. In conclusion, this study indicates that assessing the proliferative activity of phaeochromocytomas by MIB-1 immunohistochemistry can predict the occurrence of metastases. The predictive value of S100 immunostaining, tumour size, and extra-adrenal location of the tumour was also confirmed.

Adolescent↗
PubMed2000

RET is expressed but not mutated in extra-adrenal paragangliomas.

This study has investigated the role of the RET proto-oncogene, which has been identified as the susceptibility gene for multiple endocrine neoplasia (MEN) type 2, in the development of sporadic and familial extra-adrenal paragangliomas. RET protein expression was analysed by immunohistochemistry. Subsequently, DNA extracted from 52 tumours of 44 patients was screened for somatic RET point mutations in exons 10, 11, and 13-16, where oncogenic mutations have recently been described in a subset of sporadic medullary thyroid carcinomas and phaeochromocytomas. The methods employed included non-isotopic polymerase chain reaction-based single strand conformation polymorphism (PCR-SSCP) analysis and heteroduplex gel electrophoresis, followed by direct sequencing of PCR products. RET protein expression was demonstrated in all ten paragangliomas tested. However, none of the familial or sporadic extra-adrenal paragangliomas contained somatic mutations in exons 10, 11, or 13-16 of the RET proto-oncogene, whereas control samples with known mutations in these exons exhibited the expected band shift, or yielded an additional band with retarded migration. Although paragangliomas exhibit RET protein expression, these data indicate that oncogenic RET proto-oncogene mutations do not appear to be generally important in the formation of sporadic paragangliomas.

Adult↗
PubMed2000

Absence of a PDX-1 mutation and normal gastroduodenal immunohistology in a child with pancreatic agenesis.

Pancreatic agenesis is a rare condition, of which only a limited number of cases have been described. One recent paper reported a homozygous mutation in the pancreatic duodenal homeobox gene 1 (PDX-1) in a child with pancreatic agenesis. We report a 6-year-old boy with pancreatic agenesis, treated medically, without abnormalities in the PDX-1 gene coding sequence and with normal gastroduodenal endocrine cell distribution. Genes other than PDX-1 also appear to be involved in human pancreatic agenesis.

Biopsy↗
PubMed2000

Losses of chromosomes 1p and 3q are early genetic events in the development of sporadic pheochromocytomas.

Despite several loss of heterozygosity studies, a comprehensive genomic survey of pheochromocytomas is still lacking. To identify DNA copy number changes which might be important in tumor development and progression and which may have diagnostic utility, we evaluated genetic aberrations in 29 sporadic adrenal and extra-adrenal pheochromocytomas (19 clinically benign tumors and 10 malignant lesions). Comparative genomic hybridization was performed using directly fluorochrome-conjugated DNA extracted from frozen (16) and paraffin-embedded (13) tumor tissues. The most frequently observed changes were losses of chromosomes 1p11-p32 (86%), 3q (52%), 6q (34%), 3p, 17p (31% each), 11q (28%), and gains of chromosomes 9q (38%) and 17q (31%). No amplification was identified and no difference between adrenal and extra-adrenal tumors was detected. Progression to malignant tumors was strongly associated with deletions of chromosome 6q (60% versus 21% in clinically benign lesions, P = 0.0368) and 17p (50% versus 21%). Fluorescence in situ hybridization confirmed the comparative genomic hybridization data of chromosomes 1p, 3q, and 6q, and revealed aneuploidy in some tumors. Our results suggest that the development of pheochromocytomas is associated with specific genomic aberrations, such as losses of 1p, 3q, and 6q and gains of 9q and 17q. In particular, tumor suppressor genes on chromosomes 1p and 3q may be involved in early tumorigenesis, and deletions of chromosomes 6q and 17p in progression to malignancy.

Adult↗
PubMed2000

E-cadherin-catenin cell-cell adhesion complex and human cancer.

BACKGROUND: The E-cadherin-catenin complex plays a crucial role in epithelial cell-cell adhesion and in the maintenance of tissue architecture. Perturbation in the expression or function of this complex results in loss of intercellular adhesion, with possible consequent cell transformation and tumour progression. Recently, much progress has been made in understanding the interaction between the different components of this protein complex and how this cell-cell adhesion complex is modulated in cancer cells. METHODS: This is an update of the role of the E-cadherin-catenin complex in human cancers. It emphasizes new features and the possible role of the complex in clinical practice, discussed in the light of 165 references obtained from the Medline database from 1995 to 1999. RESULTS: More evidence is now appearing to suggest that disturbance in protein-protein interaction in the E-cadherin-catenin adhesion complex is one of the main events in the early and late steps of cancer development. An inverse correlation is found between expression of the E-cadherin-catenin complex and the invasive behaviour of tumour cells. Therefore, E-cadherin-catenin may become a significant prognostic marker for tumour behaviour. Besides its role in establishing tight cell-cell adhesion, beta- catenin plays a major role in cell signalling and promotion of neoplastic growth. This suggests its dual role as a tumour suppressor and as an oncogene in human cancers. CONCLUSION: Recent developments show that the E-cadherin-catenin complex is more than a 'sticky molecular complex'. Further studies may yield greater insight into the early molecular interactions critical to the initiation and progression of tumours. This should aid the development of novel strategies for both prevention and treatment of cancer.

Animals↗
PubMed2000

Human oesophageal adenocarcinoma cell lines JROECL 47 and JROECL 50 are admixtures of the human colon carcinoma cell line HCT 116.

In two recently described human oesophageal adenocarcinoma cell lines JROECL 47 and JROECL 50, derived from one tumour, we detected identical E-cadherin and beta-catenin gene mutations as in colon carcinoma cell line HCT 116. We demonstrate by HLA-typing, mutation analysis and microsatellite analysis that cell lines JROECL 47 and JROECL 50 are admixtures of the human colon adenocarcinoma cell line HCT 116.

Adenocarcinoma↗
PubMed1999

Comparative genomic hybridization of cancer of the gastroesophageal junction: deletion of 14Q31-32.1 discriminates between esophageal (Barrett's) and gastric cardia adenocarcinomas.

Incidence rates have risen rapidly for esophageal and gastric cardia adenocarcinomas. These cancers, arising at and around the gastroesophageal junction (GEJ), share a poor prognosis. In contrast, there is no consensus with respect to clinical staging resulting in possible adverse effects on treatment and survival. The goal of this study was to provide more insight into the genetic changes underlying esophageal and gastric cardia adenocarcinomas. We have used comparative genomic hybridization for a genetic analysis of 28 adenocarcinomas of the GEJ. Eleven tumors were localized in the distal esophagus and related to Barrett's esophagus, and 10 tumors were situated in the gastric cardia. The remaining seven tumors were located at the junction and could not be classified as either Barrett-related, or gastric cardia. We found alterations in all 28 neoplasms. Gains and losses were distinguished in comparable numbers. Frequent loss (> or = 25% of all tumors) was detected, in decreasing order of frequency, on 4pq (54%), 14q (46%), 18q (43%), 5q (36%), 16q (36%), 9p (29%), 17p (29%), and 21q (29%). Frequent gain (> or = 25% of all tumors) was observed, in decreasing order of frequency, on 20pq (86%), 8q (79%), 7p (61%), 13q (46%), 12q (39%), 15q (39%), 1q (36%), 3q (32%), 5p (32%), 6p (32%), 19q (32%), Xpq (32%), 17q (29%), and 18p (25%). Nearly all patients were male, and loss of chromosome Y was frequently noted (64%). Recurrent high-level amplifications (> 10% of all tumors) were seen at 8q23-24.1, 15q25, 17q12-21, and 19q13.1. Minimal overlapping regions could be determined at multiple locations (candidate genes are in parentheses): minimal regions of overlap for deletions were assigned to 3p14 (FHIT, RCA1), 5q14-21 (APC, MCC), 9p21 (MTS1/CDKN2), 14q31-32.1 (TSHR), 16q23, 18q21 (DCC, P15) and 21q21. Minimal overlapping amplified sites could be seen at 5p14 (MLVI2), 6p12-21.1 (NRASL3), 7p12 (EGFR), 8q23-24.1 (MYC), 12q21.1, 15q25 (IGF1R), 17q12-21 (ERBB2/HER2-neu), 19q13.1 (TGFB1, BCL3, AKT2), 20p12 (PCNA), 20q12-13 (MYBL2, PTPN1), and Xq25. The distribution of the imbalances revealed similar genetic patterns in the three GEJ tumor groups. However, loss of 14q31-32.1 occurred significantly more frequent in Barrett-related adenocarcinomas of the distal esophagus, than in gastric cardia cancers (P = 0.02). The unclassified, "pure junction" group displayed an intermediate position, suggesting that these may be in part gastric cardia tumors, whereas the others may be related to (short-segment) Barrett's esophagus. In conclusion, this study has, fist, provided a detailed comparative genomic hybridization-map of GEJ adenocarcinomas documenting new genetic changes, as well as candidate genes involved. Second, genetic divergence was revealed in this poorly understood group of cancers.

Adenocarcinoma↗
PubMed1999

Prognostic value of p53, bcl-2, and c-erbB-2 protein expression in phaeochromocytomas.

Many studies have tried to discriminate malignant from benign phaeochromocytomas, but until now no widely accepted histological, immunohistochemical, or molecular methods have been available. In this study of 29 malignant and 85 benign phaeochromocytomas from 102 patients, immunohistochemistry was performed with antibodies to the tumour suppressor gene product p53 and the proto-oncogene products bcl-2 and c-erbB-2, using the avidin-biotin complex method. Malignant phaeochromocytomas showed a statistically significant higher frequency of p53 (p=0.042) and bcl-2 (p=0.037) protein expression than their benign counterparts. The combination of both markers showed an even higher significance (p=0.004), to which both markers contributed equally. Overexpression of c-erbB-2 was associated with the occurrence of familial phaeochromocytomas (p=0. 001), but no difference was found between benign and malignant cases. In conclusion, p53, bcl-2, and c-erbB-2 all appear to be involved in the pathogenesis of a proportion of phaeochromocytomas. Immunoreactivity to p53 and bcl-2 proteins may help to predict the clinical behaviour of phaeochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1999

Identification of a homozygous deletion at 8p12-21 in a human prostate cancer xenograft.

One of the most frequent genetic abnormalities in prostate cancer is loss of the complete or part of the short arm of chromosome 8, indicating the localization of one or more tumor suppressor genes on this chromosomal arm. Using allelotyping, a frequently deleted region in prostate cancer in a genetic interval of approximately 17 cM between sequence tagged sites D8S87 and D8S133 at chromosome arm 8p12-21 was previously detected. A detailed physical map of this region is now available. Using known and novel polymorphic and nonpolymorphic sequence tagged sites in this interval, a search for homozygous deletions in DNAs from 14 prostate cancer-derived cell lines and xenografts was carried out. In DNA from xenograft PC133, the presence of a small homozygously deleted region of 730-1,320 kb was unambiguously established. At one site, the deletion disrupts the Werner syndrome gene. Data from allelotyping were confirmed and extended by fluorescence in situ hybridization analysis of PC133 chromosome spreads using centromere, YAC, and PAC chromosome 8 probes.

Animals↗