Biomedical subjects

H Christiansen

Publications and source records attributed to H Christiansen.

At least 19 recordsLinked to original sources

PubMed2001

Expression of P27(KIP1) is prognostic and independent of MYCN amplification in human neuroblastoma.

Amplification of the MYCN gene is significantly associated with an unfavorable prognosis and rapid progression in human neuroblastoma tumors. One potential mechanism by which MYCN may cause these effects is by deregulating cell proliferation. Tissue culture experiments support a model in which MYC genes stimulate cell cycle progression by antagonizing the function of the cell cycle inhibitor p27(kip1). In culture, activation of MYC induces both sequestration of p27(kip1) by cyclin D complexes and its subsequent proteolytic degradation. We have tested whether this model applies to human neuroblastoma in a retrospective study of 100 primary tumor biopsy samples from neuroblastoma patients with a documented follow-up. Consistent with this hypothesis, MYCN-amplified tumors express high levels of both cyclin A and proliferating cell nuclear antigen, 2 marker proteins of cell proliferation. Further, expression levels of p27(kip1) are of prognostic significance in human neuroblastoma patients. Similar to tissue culture systems, p27(kip1) is sequestered by cyclin D complexes in a subset of human neuroblastoma samples. Surprisingly, however, expression levels of p27(kip1) are prognostic independent of MYCN amplification, and tumors that have an amplified MYCN gene do not express elevated levels of D-type cyclins or contain significantly lower levels of p27(kip1). Our data do not support a model in which regulation of p27(kip1) function is an important mechanism by which amplified MYCN deregulates cell proliferation in neuroblastoma.

Biomarkers, Tumor↗

PubMed2000

Gene expression of neuronal nitric oxide synthase and adrenomedullin in human neuroblastoma using real-time PCR.

The objective of our study was to assess the gene expression of the antiproliferative systems neuronal nitric oxide synthase (nNOS) and adrenomedullin (AM) in human neuroblastoma. A novel real-time PCR method was evaluated using neuropeptide Y (NPY) for validation. Glyceraldehyd-3-phospate dehydrogenase (GAPDH) and NPY gene expression in neuroblastomas of 50 patients were measured in parallel by competitive quantitative and TaqMan real-time RT-PCR. AM and nNOS mRNA were determined by real-time PCR. Our results showed a linear relationship between competitive quantitative and real-time RT-PCR measurements of NPY and GAPDH (r = 0.87 and r = 0.92, respectively). AM and nNOS mRNA was found in all tumor samples. AM/GAPDH mRNA increased with higher differentiation according to Shimada (p = 0.013). There was no relation between MYCN amplification nor with the tumor stage (p = 0.78 and p = 0.30, respectively). AM/GAPDH did not relate to recurrence or death in a 5-year follow-up period. Neuronal NOS/GAPDH expression did not relate to any biological or clinical parameter of prognosis or differentiation. Similar results were obtained when the neuronal marker protein gene product 9.5 (PGP9.5) was used to normalize mRNA concentration. In conclusion, TaqMan real-time PCR appears to be a reliable method to quantify gene expression in neuroblastomas. Adrenomedullin mRNA in neuroblastoma is linked to tumor differentiation but not to prognostic markers.

Adolescent↗

PubMed2000

Telomerase is a strong indicator for assessing the proneness to progression in neuroblastomas.

BACKGROUND: As traditional parameters do not ensure completely accurate prognostic grouping in neuroblastoma (NB), new molecular markers are needed for assessing the individual patient's prognosis more precisely. PROCEDURE, RESULTS, AND CONCLUSIONS: Based on 133 NB, we show that telomerase activity (TA) is a powerful, independent prognostic marker for all stages and is capable of differentiating between good and poor outcome in putative 'favorable' clinical or biological subgroups of NB patients. Analysis of gene and protein expression of telomerase subunits suggests that the presence or absence of TA in NB is strongly correlated with expression levels of both the catalytic subunit hTERT and the internal RNA component (hTR).

Disease Progression↗

PubMed2000

Telomerase activity and telomerase subunits gene expression patterns in neuroblastoma: a molecular and immunohistochemical study establishing prognostic tools for fresh-frozen and paraffin-embedded tissues.

PURPOSE: We have recently demonstrated that telomerase activity (TA) is an independent prognostic factor in neuroblastomas. In the present study, the prognostic impact of TA and gene expression of the three major telomerase subunits is evaluated by molecular and immunohistochemical techniques in fresh-frozen and paraffin-embedded tissues. PATIENTS AND METHODS: One hundred thirty-three neuroblastomas of all stages were analyzed for TA. The TA levels of 75 neuroblastoma cases were correlated with gene expression of telomerase subunits hTRT, human telomerase RNA (hTR), and telomerase protein 1 (TP1) by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), using an innovative approach on the LightCycler instrument (Roche Diagnostics, Mannheim, Germany). For selected cases, the applicability of RT-PCR and immunohistochemistry for hTRT expression analysis was investigated in paraffin-embedded tissues. TA and subunit expression patterns were correlated with traditional prognostic indicators and disease outcome. RESULTS: TA was present in a total of 39 (29.3%) of 133 neuroblastomas and in 31 (29.8%) of 104 initial neuroblastomas without cytotoxic pretreatment. TA was significantly correlated with both event-free and overall survival (P <.0001). Furthermore, we found a significant correlation between expression levels of TA and hTRT (P <.0001) as well as hTR (P <.001). Multivariate analysis revealed only TA and tumor stage but not serum lactate dehydrogenase, MYCN amplification, or age at diagnosis as independent prognostic factors. CONCLUSION: The significant correlation with clinical outcome strongly recommends that analysis of TA be incorporated into the clinical investigation of each individual neuroblastoma at the time of diagnosis. Because the mere presence or absence of TA without further quantification is sufficient basis for predicting disease outcome, the telomeric repeat amplification protocol assay could be complemented with but not replaced by analysis of hTRT or hTR expression.

Biomarkers, Tumor↗

PubMed1999

Gain of chromosome arm 17q and adverse outcome in patients with neuroblastoma.

BACKGROUND: Gain of genetic material from chromosome arm 17q (gain of segment 17q21-qter) is the most frequent cytogenetic abnormality of neuroblastoma cells. This gain has been associated with advanced disease, patients who are > or =1 year old, deletion of chromosome arm 1p, and amplification of the N-myc oncogene, all of which predict an adverse outcome. We investigated these associations and evaluated the prognostic importance of the status of chromosome 17. METHODS: We compiled molecular cytogenetic analyses of chromosome 17 in primary neuroblastomas in 313 patients at six European centers. Clinical and survival information were collected, along with data on 1p, N-myc, and ploidy. RESULTS: Unbalanced gain of segment 17q21-qter was found in 53.7 percent of the tumors, whereas the chromosome was normal in 46.3 percent. The gain of 17q was characteristic of advanced tumors and of tumors in children > or =1 year of age and was strongly associated with the deletion of 1p and amplification of N-myc. No tumor showed amplification of N-myc in the absence of either deletion of 1p or gain of 17q. Gain of 17q was a significant predictive factor for adverse outcome in univariate analysis. Among the patients with this abnormality, overall survival at five years was 30.6 percent (95 percent confidence interval, 21 to 40 percent), as compared with 86.0 percent (95 percent confidence interval, 78 to 91 percent) among those with normal 17q status. in multivariate analysis, gain of 17q was the most powerful prognostic factor, followed by the presence of stage 4 disease and deletion of 1p (hazard ratios, 3.4, 2.3, and 1.9, respectively). CONCLUSIONS: Gain of chromosome segment 17q21-qter is an important prognostic factor in children with neuroblastoma.

Analysis of Variance↗

PubMed1999

Telomerase activity distinguishes between neuroblastomas with good and poor prognosis.

BACKGROUND: Treatment of neuroblastoma has remained a major challenge in pediatric oncology because the assessment of the individual prognosis, particularly in disseminated disease is still obscure. Previous studies have correlated clinical outcome with activity levels of telomerase, a cellular reverse transcriptase which has been detected in the majority of human malignant tumors. PATIENTS AND METHODS: In this blind-trial study, a non-radioactive telomeric repeat amplification protocol (TRAP) with an internal telomerase-assay standard was used on an automated laser fluorescence sequencer for the detection and semiquantitative analysis of telomerase activity (TA) in 67 neuroblastomas of all clinical stages from the German Neuroblastoma Trial and 2 ganglioneuromas. TA levels were correlated with event-free and overall survival rates and established prognostic markers such as MYCN. RESULTS: TA was present in 14 of 69 (20%) samples, including 3 of 22 stage IVS, 8 of 14 stage IV, 1 of 10 stage III, 1 of 7 stage II and 1 of 14 stage I neuroblastomas and 0 of 2 ganglioneuromas. We found a strong statistical correlation between the presence of TA and poor clinical prognosis with regard to all tumor stages. Multivariate analysis revealed TA as an independent prognostic marker. In particular, the analysis of TA in IVS neuroblastomas distinguished two different prognostic groups. CONCLUSIONS: Our data suggest that TA is an independent prognostic marker in neuroblastoma which, in combination with other markers such as MYCN, may proof useful in assessing the individual patient's prognosis.

Amino Acid Sequence↗

PubMed1999

Sublocalization of putative tumor suppressor gene loci on chromosome arm 14q in neuroblastoma.

RFLP and microsatellite analysis with 23 polymorphic markers spanning the entire long arm of chromosome 14 in 108 neuroblastomas showed allelic loss in 19 out of 107 (18%) informative tumors, placing 14q among the most frequently affected chromosomal regions in neuroblastoma. One minimal deletion region could be sublocalized in 17 of 19 cases between markers D14S1 and D14S16, and a second one between markers D14S17 and D14S23 in band 14q32. Furthermore, breakpoints in bands 14q23 and 14q12 were detected. These results suggest the presence of at least two putative tumor suppressor gene loci on chromosome 14. Survival analyses revealed no prognostic impact of allelic loss of 14q in neuroblastoma. Genes Chromosomes Cancer 26:40-46, 1999.

Chromosome Mapping↗

PubMed1998

Plasma neuropeptide Y of children with neuroblastoma in relation to stage, age and prognosis, and tissue neuropeptide Y.

The objective of this study was to relate plasma neuropeptide Y (NPY) concentrations of patients with neuroblastoma with the stage of the disease, the patients' age, the prognosis, the tumor mRNA expression and with the effect on tumor cell proliferation. Plasma NPY of 85 patients with neuroblastoma was measured by radioimmunoassay. The patients' median age was 18 months (range, three weeks-12 years). Ten children with childhood tumors that did not affect neurological or neuroendocrine structures and ten healthy children served as control groups. NPY mRNA expression in neuroblastoma tissue was assessed by Northern blot analysis. Proliferation of neuroblastoma cells (SK-N-MC and CHP 234) was evaluated by 5-bromo-2'-deoxyuridine incorporation during DNA synthesis in vitro. Plasma NPY levels were significantly higher in stage 3 (p < 0.05), 4 (p < 0.001) and 4S (p < 0.05) patients than in both control groups. Plasma levels above 8 pmol/l were only seen in stages 2 (17%), 3 (32%), 4 (45%) and 4S (44%). Seven of the 12 patients (58%) who died had NPY levels above 8 pmol/l (vs. 29% in survivors; p = 0.05). In patients with longer follow-up monitoring, relapse coincided with increasing NPY levels. There was no relationship between the patients' age and their plasma NPY concentrations (r = 0.08; p = 0.49). No relation was found between NPY mRNA expression in tumor tissue and NPY plasma concentrations of the ten patients (r = 0.08; p = 0.81). NPY in the supernatant of neuroblastoma cells did not alter the 5-bromo-2'-deoxyuridine incorporation during DNA synthesis. In summary, NPY plasma concentrations in patients with neuroblastoma relate to the stage of the disease. The relation to the prognosis is at the threshold of significance. No relation between tissue and plasma NPY, nor any effect of NPY on proliferation of tumor cells was found.

Age Factors↗

PubMed1998

Resumption of rapid proliferation from lag phase in cultures of Saccharomyces cerevisiae in poor nutrient conditions. Effect of surface and intracellular signalling mechanisms.

Saccharomyces cerevisiae was inoculated into a dilute synthetic minimal medium with glycerol as the carbon source. The number of live cells in the cultures was determined by colony counts on agar plates. Untreated control cells had doubled in number about once at the end of the first week and had gone through eight doublings by the end of the second week. Addition of either 8-bromo-cyclic guanosine monophosphate (8-bromo-cGMP) or human recombinant insulin, made the cells go through 12 and 10 doublings, respectively, by the end of the first week. In contrast, 8-bromo-cyclic adenosine monophosphate (8-bromo-cAMP) had only slight stimulating effects on cell multiplication, but if it was combined with phorbol-12-myristate-13-acetate (PMA) the cells went through about 12 doublings during the first week. Addition of LY 83583, an inhibitor of soluble guanylate cyclase, prevented cell proliferation. Further addition of 8-bromo-cGMP bypassed this inhibition. Singly, bradykinin or PMA did not affect cell multiplication. However, when these two compounds were combined, the cells went through about 10 doublings during the first week. Neither bradykinin, nor PMA had any releasing effect on the inhibition of LY 83583. These results indicate the existence of several routes leading to cell proliferation in wildtype S. cerevisiae cells.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1998

10 years' neuroblastoma screening in Europe: preliminary results of a clinical and biological review from the Study Group for Evaluation of Neuroblastoma Screening in Europe (SENSE).

Between January 1986 and May 1996, 870,313 children were tested in European neuroblastoma (NB) screening programmes. Among these children, 82 cases of NB (age range 4-24 months, median 11 months) were detected by screening. 83% of the patients had localised NB and 17% were diagnosed with generalised NB (stage 4, 10%; stage 4s, 7%). Unfavourable biological markers (MYCN amplification, loss of heterozygosity (LOH) 1p36, DNA di/tetraploidy) were observed in 14% of 76 biologically examined cases. The median follow-up time of all the patients was 21.5 months (range 1-101 months). To date, 69 patients are in complete remission (CR) and 2 patients have died due to therapy (stage 4, 1 patient; stage 3, 1 patient with unfavourable markers). Apart from screened patients, 16 other patients with NB were found who had previously had a normal screening test, i.e. 'false negative' patients (age range 10-41 months, median 31.5 months). The median interval between screening and diagnosis was 24.5 months (range 6-35 months). 11 of the 'false negative' patients suffered from generalised NB (stage 4) and 5 had localised NB at diagnosis. Unfavourable biological markers were observed in 7/12 patients. 5 patients have died, 2 achieved partial remission and 9 CR. 9 of the 11 patients with unfavourable biological markers diagnosed due to NB screening are currently in CR. It is very likely that, among the patients without unfavourable biological markers, we detected tumours which may have regressed spontaneously. These children may have undergone 'unnecessary,' but unavoidable, diagnostic procedures and therapy. To reduce the number of 'false negative' patients, a later screening could be helpful and should be evaluated.

Age Distribution↗

PubMed1998

Comparative genomic hybridization and telomerase activity analysis identify two biologically different groups of 4s neuroblastomas.

Chromosomal aberrations of 20 stage 4s neuroblastomas were analysed by comparative genomic hybridization (CGH). In a subset of 13/20 tumours, telomerase activity was evaluated by the telomeric repeat amplification protocol (TRAP). The CGH data were compared with the CGH results of ten stage 1 and 2 (stage 1/2) and 22 stage 3 and 4 (stage 3/4) neuroblastomas. A total of 17/20 stage 4s neuroblastomas did not progress clinically, whereas tumour progression with lethal outcome occurred in 3/20 cases. The CGH data of clinically non-progressing stage 4s tumours revealed a high rate of whole-chromosome aberrations (73.4%) with an overrepresentation of mainly chromosomes 2, 6, 7, 12, 13, 17, 18 and an underrepresentation of mainly chromosomes 3, 4, 11, 14. MYCN amplification or 1p deletion was observed in only 1/27 or 2/17 clinically non-progressing stage 4s tumours respectively, whereas all three progressive stage 4s neuroblastomas showed MYCN amplification, 1p deletion and, in 2/3 cases, distal 17q gains. Except for one case, telomerase activity was not observed in non-progressing stage 4s neuroblastomas. In contrast, 4s tumours with lethal outcome revealed elevated telomerase activity levels. Our data suggest that stage 4s neuroblastomas belong to two biologically different groups, one of which displays the genetic features of localized stage 1/2 tumours, whereas the other mimics advanced stage 3/4 neuroblastomas.

Blotting, Southern↗

PubMed1997

Human neuroblastoma cells use either insulin-like growth factor-I or insulin-like growth factor-II in an autocrine pathway via the IGF-I receptor: variability of IGF, IGF binding protein (IGFBP) and IGF receptor gene expression and IGF and IGFBP secretion in human neuroblastoma cells in relation to cellular proliferation.

Neuroblastoma cells are thought to depend upon autocrine stimulation by IGF-II but not by IGF-I. We have studied the expression of IGF, IGFBP and IGF receptor mRNA in two human neuroblastoma cell lines, SK-N-MC and CHP, and asked whether or not the expression of the IGF system in these malignant cells determines their growth pattern. SK-N-MC cells grow with a cell doubling time of 36 hours in medium supplemented with 10% fetal calf serum whereas CHP cells only grow with a doubling time of 72 h. In addition, the SK-N-MC cell line has a plating efficiency ten times greater than the CHP cell line. RNase protection assays were performed using (32)P-labelled riboprobes and RNA that had been purified from SK-N-MC and CHP cells respectively. A 520 bases human IGF-I, a 556 bases human IGF-II, a 480 bases human IGF-I receptor and a 250 human IGF-II/mannose-6-phosphate (M6P) receptor probe were radiolabelled as were human IGFBP-1, -2, -3, -4, -5 and -6 probes. While both SKNMC and CHP neuroblastoma cells expressed mRNAs for IGFBP-2, -4, and -6 no signal was detected for IGFBP-1, and -3 and only SK-N-MC cells expressed IGFBP-5 mRNA. In addition, a 400 bases protected band was seen with the IGF-I receptor probe and a 260 bases protected band with the IGF-IIM6P receptor probe in either cell line. Interestingly, a 300 bases protected species was detected with the IGF-II probe in CHP cell RNA whereas SK-N-MC cells did not express IGF-II transcripts. Conversely, SK-N-MC cells expressed a 520 bases IGF-I transcript while CHP cells did not show IGF-I mRNA expression. As determined by specific radioimmunoassays SK-N-MC cells secreted 0.75+/-0.02 ng/ml IGF-I, 1.2+/-0.04 ng/ml IGF-II and 149+/-2.1 ng/ml IGFBP-2 within 24 h, whereas CHP cells secreted 0.1+/-0.01 ng/ml IGF-I, but 6.2+/-0.1ng/ml IGF-II and 254.8+/-5.5 ng/ml IGFBP-2 (N=5). IGFBP-2 secretion correlated positively with IGF-II secretion in CHP cells (r=0.85, P=0.05) and negatively with IGF-I (r= -0.9, P<0.01) in SK-N-MC cells. In conclusion, SK-N-MC cells which grow rapidly and have a high plating efficiency, express IGF-I, while CHP cells that grow more slowly express IGF-II. We hypothesize that neuroblastoma cells depend upon autocrine stimulation by either IGF-I or IGF-II. Variable sensitivity to growth inhibitors or apoptotic processes may be related to the differential expression of the IGF system.

Autocrine Communication↗

PubMed1997

Comparative genomic hybridization (CGH) analysis of neuroblastomas--an important methodological approach in paediatric tumour pathology.

Comparative genomic hybridization (CGH) was applied to 35 neuroblastomas to obtain a global view of genetic imbalances. Results were validated by means of Southern blot hybridization (detection of N-myc amplification), loss of heterozygosity (LOH) studies (detection of deletion 1p), and interphase cytogenetics [dual labelling fluorescence in situ hybridization (FISH) of centromeric 17 and erbB-2]. CGH allowed sensitive detection of N-myc amplification and chromosome 1p deletion, representing the most established prognostic markers of neuroblastoma. In addition, a high rate of chromosome 17 aberrations (63 per cent) with possible prognostic relevance was observed. Previously unreported high level copy number increases indicating oncogene amplification were mapped to chromosome subbands 2p13-14 and 3q24-26. Other recurrent regional chromosomal aberrations were localized on 11q, 12q, 13q, 14q, and 15q. CGH results were fully consistent with data of Southern blot analysis and LOH study, as well as interphase cytogenetics. These results show that CGH is a sensitive method for the detection of all prognostically relevant genetic alterations in neuroblastomas; that CGH considerably simplifies the detection of these alterations, resulting in a single methodological approach; and that CGH is a powerful tool to elucidate previously unknown genetic changes in neuroblastomas.

Blotting, Southern↗

PubMed1997

[Primitive neuroectodermal tumor].

The primitive neuroectodermal tumor is a rare soft tissue neoplasm occurring in children and young adults. It derives from a carcinogeneic alteration of pluripotent neural crest cells, caused by a balanced reciprocal translocation t(11;22) (q24;q12). Treatment of this undifferentiated, extremely malignant small cell tumor is carried out in compliance with the soft tissue trail (CWS) from the German Society of Pediatric Oncology. Biopsy-proven diagnosis is followed by primary chemotherapy, which in 95% of cases leads to remission, allowing excision of the remainder of the tumor without mutilation and avoidance of intraoperative tumor cell dissemination. After excision, irradiation of the tumor site and two further sequences of chemotherapy are performed. If PNETs of the paravertebral region cause symptoms of paralysis and immediate surgery is required, postoperative chemotherapy, a second-look operation and irradiation are mandatory. Between 1986 and 1994, in cooperation with our pediatric and radiotherapy colleagues, we treated ten patients. In four patients (median age, 14 years) the PNET originated from the chest wall, in six patients from the paravertebral and retroperitoneal region. Five patients died after 20 months on average, while the remaining five patients are in full remission after 31, 46, 50, 51 and 91 months, respectively.

Adolescent↗

PubMed1997

Analysis of candidate gene co-amplification with MYCN in neuroblastoma.

Previous studies have revealed that the MYCN gene spans approximately 7kb, while the amplicon has been estimated to be 100 kb to 1 Mb long [1-3]. This implies that several other genes may be present on the MYCN amplicon. Such co-amplified genes could contribute to the malignant phenotype and might provide an explanation for why not all patients with MYCN amplification have a poor outcome. We investigated 7 neuroblastoma cell lines and 167 primary tumours for the co-amplification of candidate genes known to be present near the MYCN locus: ornithine decarboxylase, ribonucleotide reductase, syndecan-1 and a DEAD box protein gene, DDX1. We also investigated further the pG21 expressed sequence previously reported to be co-amplified with MYCN. No co-amplification with the first 3 genes was found in any of the cell lines or tumour samples. DDX1 was found to be amplified along with MYCN in 4/6 (67%) cell lines and 18/38 (47%) of the MYCN amplified tumours. No amplification of DDX1, ODC1, RRM2 or syndecan-1 was found in the absence of MYCN amplification. DDX1 co-amplification was observed to occur mainly in stage 4 or 4S patients. With the exclusion of those with 4S disease, patients with DDX1 co-amplification had a significantly shorter mean (+/- SE) disease-free interval (4.1 +/- 1.4, n = 8 months) compared with patients with MYCN amplification alone (19.6 +/- 4.5, n = 17) (P = 0.04, Welch's unpaired t-test). The pG21 sequence was identical to part of the DDX1 gene. These observations indicate that there is at least 1 other gene co-amplified with MYCN in a proportion of cases and that those patients with DDX1 co-amplification tend to relapse more quickly. It also implies that the MYCN amplicon is of varied size and/or position relative to the MYCN gene.

Adolescent↗

PubMed1997

The current contribution of molecular factors to risk estimation in neuroblastoma patients.

The association of molecular characteristics with prognosis has been reported, but not their relationship with each other and their impact in the context of known clinical risk factors. In this study, data of 1249 consecutive intent-to-treat-neuroblastoma patients with more than 1 year follow-up were examined by multivariate analysis using loglinear and Cox proportional hazard regression models on a stage-related basis (stages 1-3: 600, 4S: 116, 4: 533). In a first step, risk factors were identified from 18 selected clinical variables, and risk groups defined. The second step investigated whether molecular characteristics (MYCN, LOH 1p, del 1p, CD44, N-ras, NGF-R, bcl-2, APO-1 (CD95)) contributed additional prognostic information to the model. The loglinear model demonstrated several interactions between clinical factors. By the Cox regression model, seven independent clinical risk factors were found for stages 1-3, seven for stage 4 and two for stage 4S. By subsequent introduction of all molecular variables, MYCN amplification only added significant prognostic information to the clinical factors in localised and stage 4 neuroblastoma. The models allowed the definition of risk groups for stages 1-3 patients by age (e beta = 5.09) and MYCN (e beta = 4.26), for stage 4 by MYCN (e beta = 2.78) and number of symptoms (e beta = 2.44) and for stage 4S by platelet count (e beta = 3.91) and general condition (e beta = 2.99). Molecular factors and in particular MYCN contribute significantly to risk estimation. In conjunction with clinical factors, they are powerful tools to define risk groups in neuroblastoma.

Adolescent↗

PubMed1997

Disseminated neuroblastomas under 1 year of age: cell biology and prognosis.

Tumor specimens of 203 infants with neuroblastomas of different clinical stages-registered in successive multicenter clinical trials of the German Society of Pediatric Oncology-could be examined for N-myc amplification, chromosome 1-ploidy and-structure, CD44 std. expression (in tumor tissue, and also in patient's sera). Eighty-seven (= 43%) of these infants had a non-localized, disseminated neuroblastoma, mainly involving sympathetic nerve tissue, lymph nodes, liver, skin, bone marrow and bones (46 patients were classified into the 4 group, 41 patients in the true 4 group). If the clinical classification between stage 4 and stage 4s was neglected, then 17 of these infants (= 20%) had N-myc amplification (4-64 copies) with 16 already dead. Seven of 9 examined patients with true stage 4- had chromosome 1p aberrations (with N-myc amplification in 5), and among the dead there were 2 with CD44 negative expression. In another series, serum CD44 std. was measured by ELISA, and the highest (significantly different) Kruskal-Wallis mean rank values (147.8) were found in infants (n = 6) with stage 4s compared to the low mean-rank-value of 71.9 in patients with stage 4 (n = 65). Stage 1-3 patients (n = 42) had values of 99.8-88.6. Thus, infants with disseminated neuroblastomas, showing non-diploidy, normal chromosome 1p structure, non-N-myc amplification and high CD44 std. expression in tumor tissue, and also high CD44 std. values in serum, will have the highest chance of survival due to tumor-non-progression. On the other hand, N-myc amplification in the tumor cells was found to be characteristic for stage 4s neuroblastoma patients with tumor progression (n = 6). Therefore, 4s neuroblastoma-patients with N-myc amplified tumors should be aggressively treated like true stage 4 tumor patients.

Enzyme-Linked Immunosorbent Assay↗

PubMed1996

A novel type of DNA-binding protein interacts with a conserved sequence in an early nodulin ENOD12 promoter.

The pea genes PsENOD12A and PsENOD12B are expressed in the root hairs shortly after infection with the nitrogen-fixing bacterium Rhizobium leguminosarum bv. viciae or after application of purified Nod factors. A 199 bp promoter fragment of the PsENOD12B gene contains sufficient information for Nod factor-induced tissue-specific expression. We have isolated a Vicia sativa cDNA encoding a 1641 amino acid protein, ENBP1, that interacts with the 199 bp ENOD12 promoter. Two different DNA-binding domains were identified in ENBP1. A domain containing six AT-hooks interacts specifically with an AT-rich sequence located between positions -95 and -77 in the PsENOD12B promoter. A second domain in ENBP1 is a cysteine-rich region that binds to the ENOD12 promoter in a sequence non-specific but metal-dependent way. ENBP1 is expressed in the same cell types as ENOD12. However, additional expression is observed in the nodule parenchyma and meristem. The presence of three small overlapping ORFs in the 5'-untranslated region of the ENBP1 cDNA indicates that ENBP1 expression might be regulated at the translational level. The interaction of ENBP1 with a conserved AT-rich element within the ENOD12 promoter and the presence of the ENBP1 transcript in cells expressing ENOD12 strongly suggest that ENBP1 is a transcription factor involved in the regulation of ENOD12. Finally, the C-terminal region of ENBP1 shows strong homology to a protein from rat that is specifically expressed in testis tissue.

Amino Acid Sequence↗