http://repub.eur.nl/res/aut/2884/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/26375/ 2011-05-19T00:00:00Z Purpose: This study reevaluates the potential role of different tumour markers as prognostic indicators in untreated nephroblastoma. Methods: Expression of a broad panel of tumour markers was investigated by means of immunohistochemical analysis in 43 WT patients. Patients were treated by radical nephrectomy and had a mean follow-up of 11.9 years. Results: Generally, all the tumour markers studied were expressed in normal kidney tissue and at variable levels in the three cell types of WT (blastema, epithelium and stroma). Immunoreactive blastemal (Bcl-X, Bcl-2 and CD44s) and epithelial (Bcl-X, Bcl-2 and MIB-1) cells were present in the majority of tumours. No correlation was found between their expression and pathological stages. Univariate analysis showed that blastemal WT-1, TGF-α, VEGF, MIB-1 and p27 Kip1 were indicative for clinical progression. In a multivariate analysis, WT-1 protein expression by blastemal cells was an independent prognostic marker for clinical progression. Conclusions: The blastemal WT-1, TGF-α, VEGF, MIB-1 and p27Kip1 expression correlate with clinical progression in untreated nephroblastoma. Therefore, their expression may be of value in identifying patients with a high propensity to develop distant metastases. http://repub.eur.nl/res/pub/10310/ 2004-01-01T00:00:00Z PURPOSE: A number of studies have indicated that the tumor proliferation marker MIB-1 and cell cycle inhibitor p27(Kip1) expression are of prognostic importance in a variety of cancers. The present study was performed to evaluate the prognostic value of these molecules in Wilms' tumors. EXPERIMENTAL DESIGN: MIB-1 and p27(Kip1) expressions were investigated by the means of immunohistochemical analysis of 62 Wilms' tumor. Patients were preoperatively treated by chemotherapeutic agents and had a mean follow-up of 5.7 years. RESULTS: MIB-1 and p27(Kip1) were expressed in normal kidney tissues and in the three main components of Wilms' tumor, i.e., the blastemal, epithelial, and stromal cells. In Wilms' tumors, the percentage of MIB-1-positive cells in the blastema ranged between 0 and 42% (mean, 9.4%) and in the epithelial component between 0 and 53% (mean, 19.9%), with a significant difference (P < 0.01). The percentage of blastemal p27(Kip1)-positive cells ranged between 3 and 85% (mean, 55.1%) and for the epithelial component between 1 and 87% (mean, 59%). There was a significant inverse relationship between blastemal MIB-1 and p27(Kip1) expression in Wilms' tumor. Univariate analysis showed that blastemal MIB-1 and p27(Kip1) expression were indicative for clinical progression and tumor-specific survival. In a multivariate analysis, blastemal MIB-1 and p27(Kip1) protein expression proved to be an independent prognostic for clinical progression besides stage. CONCLUSIONS: It was concluded that both MIB-1-based proliferative activity and p27(Kip1) protein expression in the blastema have prognostic impact in Wilms' tumor. http://repub.eur.nl/res/pub/15090/ 2001-11-01T00:00:00Z Identification of genes involved in the transition from androgen-dependent to androgen-independent prostate cancer is important to extend our current knowledge of the disease. Using differential display RT-PCR analysis between androgen-dependent and androgen-independent prostate cancer cells, we have identified a novel gene, designated GC109. GC109 harbours a putative Cys-His cluster, a nuclear localisation signal, a leucine zipper and a ret finger protein (rfp)-like domain. GC109 mRNA expression in normal human tissues was found not to be restricted to the prostate. However, using a variety of 15 human cancer cell lines, GC109 mRNA was preferentially expressed in androgen-dependent LNCaP-FGC, compared with androgen-independent LNCaP-LNO, DU145 and PC3 human prostate cancer cells. Finally, the GC109 gene was mapped on human chromosome 2p24. Based on its protein domain structure and chromosomal localisation, we hypothesise that GC109 may be involved in chromosomal rearrangements in prostate cancer. http://repub.eur.nl/res/pub/9257/ 2000-01-01T00:00:00Z Neuroendocrine (NE) cells are androgen-independent cells and secrete growth-modulating neuropeptides via a regulated secretory pathway (RSP). We studied NE differentiation after androgen withdrawal in the androgen-dependent prostate cancer xenograft PC-310. Expression patterns of chromogranin A, secretogranin III, and prohormone convertase-1 were analyzed at both protein and mRNA level to mark the kinetics of NE differentiation both in vivo and in vitro. PC-310 tumor-bearing nude mice were killed at 0, 2, 5, 7, 14, and 21 days postcastration. PC-310C cultures initiated from collagenase-treated tumor tissue could be maintained up to four passages, and androgen-deprivation experiments were performed similarly. PC-310 tumor volumes decreased by 50% in 10 days postcastration. Proliferative activity and prostate-specific antigen (PSA) serum levels decreased to zero postcastration, whereas PSA levels in PC-310C culture media first decreased and subsequently increased after 5 days. In vivo, androgen receptor (AR) expression decreased initially but returned to control level from 5 days postcastration on. CgA, secretogranin III, and secretogranin V expression increased in vivo from 5 days postcastration on. Subsequently, prohormone convertase-1 and peptidyl alpha-amidating monooxygenase as well as the vascular endothelial growth factor were expressed from 7 days postcastration on, and, finally, growth factors such as gastrin-releasing peptide and serotonin were expressed in a small part of the NE cells 21 days postcastration. The PC-310 tumors did not show colocalization of the AR on the NE cells in the tumor residues after 21 days. As in the PC-310 xenograft, NE differentiation was induced and AR expression relapsed after prolonged androgen suppression in PC-310C. For PC-310C cells, this relapse was associated with the secretion of PSA. PC-310C is the first culture of human prostatic cancer cells having the NE phenotype. The PC-310 model system is a potential androgen-dependent model for studying the role of NE cells in the progression of clinical prostate cancer. Androgen deprivation of NE-differentiated prostate cancer may induce the formation of both NE- and AR-positive dormant tumor residues, capable of actively producing NE growth factors via a RSP, possibly leading to hormone refractory disease. http://repub.eur.nl/res/pub/9451/ 2000-01-01T00:00:00Z BACKGROUND: The transition from androgen-dependent to androgen-independent prostate cancer is not fully understood but appears to involve multiple genetic changes. We have identified a gene, GC79, that is more highly expressed in androgen-dependent LNCaP-FGC human prostate cancer cells than in androgen-independent LNCaP-LNO human prostate cancer cells. Physiologic levels (0.1 nM:) of androgens repress expression of GC79 messenger RNA (mRNA) in LNCaP-FGC cells. To determine the role of GC79, we cloned its complementary DNA (cDNA) and functionally characterized its product. METHODS: The differentially expressed GC79 gene was cloned from human prostate cDNA libraries, sequenced, and transfected into mammalian cells to study its function. Expression of GC79 was analyzed in various adult and fetal human tissues and in prostate glands of castrated rats. The association of GC79 expression and apoptosis was investigated in COS-1 and LNCaP cells transfected with GC79 cDNA. All statistical tests are two-sided. RESULTS: Sequence analysis indicates that GC79 encodes a large, complex, multitype zinc-finger protein, containing nine C(2)H(2)-type zinc-finger domains, a cysteine-rich region, and a GATA C(4)-type zinc-finger domain. Castration-induced androgen withdrawal increased the expression of GC79 mRNA in the regressing rat ventral prostate, suggesting that the expression of GC79 mRNA is associated with the process of apoptotic cell death in the rat ventral prostate. Transfection and induction of GC79 cDNA in both COS-1 and LNCaP prostate cancer cells led to an apoptotic index that was eightfold higher (P:<.001, two-sided Student's t test) than that observed in uninduced transfected cells. CONCLUSIONS: We have cloned an androgen-repressible gene, GC79, that is potentially involved in apoptosis. This finding may have implications for the development of androgen-independent prostate cancer and, ultimately, for the treatment of prostate cancer. http://repub.eur.nl/res/pub/9550/ 2000-01-01T00:00:00Z Wilms' tumor is one of the most common solid tumors of children. The protein product of the tumor-suppressor gene, Wilms' tumor 1 (WT-1), binds to the same DNA sequences as the protein product of the early growth response 1 (EGR-1) gene. There is experimental evidence that EGR-1 is involved in controlling cell growth. The expression of both genes in Wilms' tumor was studied by others, mainly at the mRNA level. The present study evaluates the prognostic value of WT-1 and EGR-1 in 61 Wilms' tumors of chemotherapeutically treated patients at the protein level, using an immunohistochemical approach. WT-1 was expressed in normal kidney tissues and in the blastemal and epithelial component of Wilms' tumor, whereas stromal tissue was negative. EGR-1 was expressed in normal kidney tissues and in the three main cell types of Wilms' tumor. In 59 and 56% of Wilms' tumor, the blastemal cells stained for WT-1 and EGR-1, respectively. The blastemal expression of WT-1 and EGR-1 and the epithelial expression of WT-1 were statistically significantly correlated with clinical stage. WT-1 immunoreactivity correlated with EGR-1 expression. Univariate analysis showed that blastemal WT-1 and EGR-1 expression were indicative for clinical progression and tumor-specific survival, whereas epithelial staining was of no prognostic value. Multivariate analysis showed that blastemal WT-1 expression is an independent prognostic marker for clinical progression other than stage. We conclude that a relationship exists between WT-1 and EGR-1 expression in clinical nephroblastomas. Blastemal WT-1 and EGR-1 expression is related to prognosis. http://repub.eur.nl/res/pub/9049/ 1999-01-01T00:00:00Z It was previously shown in the PC-295 xenograft that the number of chromogranin A (CgA)-positive neuroendocrine (NE) cells increased after androgen withdrawal. NE cells did not proliferate and differentiated from G0-phase-arrested cells. Here we further characterized NE differentiation, androgen receptor status, and apoptosis-associated Bcl-2 expression in the PC-295 model after androgen withdrawal to assess the origin of NE cells. PC-295 tumor volumes decreased by 50% in 4 days. Intraperitoneal bromodeoxyuridine (BrdU) incorporation and MIB-1 labeling decreased to 0%, and the apoptosis was maximal at day 4. Androgen receptor expression and prostate-specific antigen (PSA) serum levels decreased rapidly within 2 days. The number of NE cells increased 6-fold at day 4 and 30-fold at day 7. Five and ten percent of the CgA-positive cells were BrdU positive after continuous BrdU labeling for 2 and 4 days, respectively. However, no MIB-1 expression was observed in CgA-positive cells. NE cells expressed the regulated secretory pathway marker secretogranin III but were negative for androgen receptor and Bcl-2. Bcl-2 expression did increase in the non-NE tumor cells. In conclusion, androgen withdrawal leads to a rapid PC-295 tumor regression and a proliferation-independent induction of NE differentiation. The strictly androgen-independent NE cells that were still present after 21 days differentiated mainly from G0-phase-arrested cells. http://repub.eur.nl/res/pub/8869/ 1997-01-01T00:00:00Z Differential gene expression between androgen-dependent (LNCaP-FGC) and androgen-independent (LNCaP-LNO) prostate cancer cells has been investigated using RNA arbitrarily primed and differential display PCR of mRNA. Four differentially expressed cDNA transcripts were identified, of which differential expression was confirmed by Northern blot analysis. Sequence analysis revealed two unknown (JC19 and GC79) and two known genes [B-cell translocation gene 1 and UDP-glucuronosyltransferase 2B15 (UGT2B15)]. JC19, GC79, and B-cell translocation gene 1 were more highly expressed in LNCaP-FGC cells compared with LNCaP-LNO cells, whereas UGT2B15 was only expressed in LNCaP-LNO cells. Androgens and 1,25-dihydroxyvitamin D3 were able to down-regulate UGT2B15 mRNA in LNCaP-LNO cells. For GC79 mRNA, down-regulation was only observed with androgens in LNCaP-FGC cells. Expression of JC19 mRNA was studied using a panel of human prostate cancer xenografts. In androgen-dependent xenografts, expression of JC19 mRNA was much higher compared with androgen-independent xenografts, in which significant expression was hardly detectable. The mRNA expression pattern in the xenografts is in good agreement with that observed in the cell culture system. In conclusion, the differential display technique used in the present study allows analysis of gene expression in vitro and in vivo and can be used for the identification of important genes involved in androgen-independent prostate cancer development.