Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions.

Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and ^{3}H/^{3}He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, J^{π}=1^{+}) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the ^{3}H/^{3}He+Ξ threshold. Experimental implications for such a state are discussed.

Observation of the (Λ)(7)He hypernucleus by the (e, e'K+) reaction.

An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

Correlating telomerase activity levels with human neuroblastoma outcomes.

Telomerase activity was analysed in 100 neuroblastoma cases. Although telomerase activity was not detected in normal adrenal tissues or benign ganglioneuromas, almost all neuroblastomas (94%) did express it, suggesting an important role for telomerase in neuroblastoma development. Neuroblastomas with high telomerase activity had other genetic changes (for example, N-myc amplification) and an unfavourable prognosis, whereas tumours with low telomerase activity were devoid of such genetic alterations and were associated with a favourable prognosis. Three neuroblastomas lacking telomerase activity regressed (stage IVS). Thus telomerase expression may be required as a critical step in the multigenetic process of tumorigenesis, and two different pathways may exist for the development of neuroblastoma.

Five-body cluster structure of the double-Λ hypernucleus (ΛΛ)(11)Be.

Energy levels of the double Λ hypernucleus (ΛΛ)(11)Be are calculated within the framework of a ααnΛΛ five-body model. Interactions between constituent particles are determined so as to reproduce reasonably the observed low-energy properties of the αα, ααn nuclei and the existing data for Λ-binding energies of the αΛ, ααΛ, αnΛ, and ααnΛ systems. An effective ΛΛ interaction is constructed so as to reproduce, within the αΛΛ three-body model, the B(ΛΛ) of (ΛΛ)(6)He, which was extracted from the emulsion experiment, the NAGARA event. With no adjustable parameters for the ααnΛΛ system, B(ΛΛ) of the ground and bound excited states of (ΛΛ)(11)Be are calculated with the Gaussian expansion method. The Hida event, recently observed at KEK-E373 experiment, is interpreted as an observation of the ground state of the (ΛΛ)(11)Be.

Consensus criteria for sensitive detection of minimal neuroblastoma cells in bone marrow, blood and stem cell preparations by immunocytology and QRT-PCR: recommendations by the International Neuroblastoma Risk Group Task Force.

Disseminating disease is a predictive and prognostic indicator of poor outcome in children with neuroblastoma. Its accurate and sensitive assessment can facilitate optimal treatment decisions. The International Neuroblastoma Risk Group (INRG) Task Force has defined standardised methods for the determination of minimal disease (MD) by immunocytology (IC) and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) using disialoganglioside G(D2) and tyrosine hydroxylase mRNA respectively. The INRG standard operating procedures (SOPs) define methods for collecting, processing and evaluating bone marrow (BM), peripheral blood (PB) and peripheral blood stem cell harvest by IC and QRT-PCR. Sampling PB and BM is recommended at diagnosis, before and after myeloablative therapy and at the end of treatment. Peripheral blood stem cell products should be analysed at the time of harvest. Performing MD detection according to INRG SOPs will enable laboratories throughout the world to compare their results and thus facilitate quality-controlled multi-centre prospective trials to assess the clinical significance of MD and minimal residual disease in heterogeneous patient groups.

Loss of imprinting of IGF2 correlates with hypermethylation of the H19 differentially methylated region in hepatoblastoma.

IGF2, a maternally imprinted foetal growth factor gene, is implicated in many childhood tumours including hepatoblastoma (HB); however, the genetic and epigenetic alterations have not comprehensively been studied. We analysed the methylation status of the H19 differentially methylated region (DMR), loss of heterozygosity (LOH) and allelic expression of IGF2 in 54 HB tumours, and found that 12 tumours (22%) with LOH, 9 (17%) with loss of imprinting (LOI) and 33 (61%) with retention of imprinting (ROI). Biallelic and monoallelic IGF2 expressions correlated with hypermethylation and normal methylation of H19 DMR, respectively, in two tumours with LOI and seven tumours with ROI. Quantitative RT-PCR analysis showed minimal expression of H19 mRNA and substantial expression of IGF2 mRNA in tumours with LOH or LOI, and substantial expression of both H19 and IGF2 mRNAs in tumours with ROI. Increased IGF2 expression with predominant embryonic P3 transcript was found in the majority of HBs with ROI and foetal livers. In contrast to the earlier reports, our findings suggest that the disruption of the enhancer competition model reported in Wilms' tumour may also occur in HB. Both frequencies of LOH and LOI seem to be lower in HB than in Wilms' tumour, reflecting the different tissue origins.

Possibility of selection of chondrogenic progenitor cells by telomere length in FGF-2-expanded mesenchymal stromal cells.

Telomere length plays an important role in regulating the proliferative capacity of cells, and serves as a marker for cell cycle history and also for their remaining replicative potential. Mesenchymal stromal cells (MSC) are known to be a significant cell source for therapeutic intervention and tissue engineering. To investigate any possible limitations in the replicative potential and chondrogenic differentiation potential of fibroblast growth factor-2-expanded MSCs (FGF(+)MSC), these cells were differentiated at various population doublings (PDs), and telomere length and telomerase activity were measured before and after differentiation. FGF(+)MSC cultured at a relatively low density maintained proliferation capability past more than 80 PD and maintained chondrogenic differentiation potential up to at least 46 PD and long telomeres up to 105 PD, despite expressing low levels of telomerase activity. Interestingly, upon chondrogenic differentiation of these cells, telomeres showed a remarkable reduction in length. This shortening was more extensive when FGF(+)MSC of higher PD levels were differentiated. These findings suggest that telomere length may be a useful genetic marker for chondrogenic progenitor cells.

Molecular epidemiology of enteritis-causing methicillin-resistant Staphylococcus aureus.

In the early 1990s, severe enteritis caused by methicillin-resistant Staphylococcus aureus (MRSA enteritis) was prevalent in Japan, but the incidence has since decreased. We compared the genotypes and phenotypes of 12 isolates that caused MRSA enteritis (enteritis isolates), detected between 1990 and 1993, with 186 non-enteritis isolates detected between 1998 and 2002. Organisms were investigated using pulsed-field gel electrophoresis (PFGE), coagulase typing and reverse passive latex agglutination to detect production of staphylococcal enterotoxins (SE) and toxic shock syndrome toxin-1 (TSST-1); and polymerase chain reaction (PCR) for detection of the structural genes entA, entB, entC, entD and tst, which encode proteins SE-A, SE-B, SE-C, SE-D and TSST-1, respectively. The 12 enteritis isolates were classified into four types and four subtypes. Only seven of the 186 non-enteritis isolates had PFGE patterns indistinguishable from the enteritis isolates. Eight of the 12 enteritis isolates had entA, entC and tst, and produced high levels of SE-A and TSST-1, but not SE-C. Of the 186 non-enteritis isolates, 157 produced SE-C and TSST-1, but not SE-A. The seven non-enteritis isolates with a PFGE pattern indistinguishable from the enteritis isolates did not produce SE-A, and showed relatively low levels of TSST-1 production. These isolates may have continued to inhabit our ward since the earlier outbreak, but acquired a different phenotype. In conclusion, the disappearance of MRSA enteritis may have resulted from the decreased incidence of enteritis-causing clones and phenotypical changes.

Telomerase activity in small-cell and non-small-cell lung cancers.

BACKGROUND: Telomerase is an enzyme that adds hexameric TTAGGG nucleotide repeats onto the ends of vertebrate chromosomal DNAs (i.e., telomeres) to compensate for losses that occur with each round of DNA replication. Somatic cells do not have telomerase activity and stop dividing when the telomeric ends of at least some chromosomes have been shortened to a critical length. It has been suggested that immortalized cells (including some, but probably not all, cancer cells) continue to proliferate indefinitely because they express telomerase. PURPOSE: To investigate whether expression of telomerase is a prerequisite for the development of naturally occurring human cancers, we assayed the levels of telomerase activity in specimens of human lung tumor and adjacent normal tissue. METHODS: Using a polymerase chain reaction-based assay, we examined telomerase activity in 136 primary lung cancer tissues and 68 adjacent noncancerous tissues obtained by surgical resection. We also studied telomerase activity in four primary and 23 metastatic lesions obtained through biopsy, (two patients) or autopsy (10 patients). Relative telomerase activity levels were estimated by serial dilutions of extracts prepared from the specimens. Telomerase activity was also assayed in extracts of cells present in pleural fluids from three patients with adenocarcinoma of the lung. RESULTS: Among surgically resected samples, telomerase activity was detected in 109 (80.1%) of 136 primary lung cancer tissues and in three (4.4%) of 68 normal adjacent tissues. All 11 surgically resected specimens of primary small-cell lung cancer (from 11 patients) revealed high levels of telomerase activity, whereas the activity ranged from undetectable to high levels in the 125 surgically resected specimens of primary non-small-cell lung cancer tissue (from 125 patients). Generally, high levels of telomerase activity were observed in metastatic lesions and tumors with altered telomere length. A few primary and, surprisingly, some metastatic tumors did not appear to have detectable telomerase activity. Telomerase activity was, however, detected in cells present in all tested pleural fluids obtained (from three patients with adenocarcinoma of the lung). CONCLUSION: The subset of non-small-cell lung cancers that exhibits only low or undetectable levels of telomerase activity may contain primarily mortal cancer cells. Cancers that exhibit high levels of telomerase activity, such as all of the small-cell lung cancers examined in this study, are likely to consist mainly of immortal cells. IMPLICATIONS: Telomerase activity may be useful both as a diagnostic marker to detect the existence of immortal lung cancer cells in clinical materials and as a target for therapeutic intervention.

Telomerase activity in human breast tumors.

BACKGROUND: The activity of the ribonucleoprotein enzyme telomerase is not detected in normal somatic cells; thus, with each cell division, the ends of chromosomes consisting of the telomeric repeats TTAGGG progressively erode. The current model gaining support is that telomerase activity in germline and immortal cells maintains telomere length and thus compensates for the "end-replication problem." PURPOSE: Our objective was to determine when telomerase activity is reactivated in the progression to malignant breast cancer and if knowledge of telomerase activity may be an indicator for the diagnosis and potential treatment of breast cancer. METHODS: Using a polymerase chain reaction-based telomerase activity assay, we examined telomerase activity in 140 breast cancer specimens (from 140 patients), four phyllodes tumors (from four patients), 38 noncancerous lesions (20 fibroadenomas, 17 fibrocystic diseases, one gynecomastia; from 38 patients), and 55 adjacent noncancerous mammary tissues (from 55 of the 140 breast cancer patients). In addition, 33 fine-needle-aspirated breast samples (from 33 patients) were analyzed. RESULTS: Among surgically resected samples, telomerase activity was detected in 130 (93%) of 140 breast cancers. Telomerase activity was detected in 68% of stage I primary breast cancers, in 73% of cancers smaller than 20 mm, and in 81% of axillary lymph node-negative cancers. Moreover, the activity was detected in more than 95% of advanced stage tumors but in only two (4%) of 55 adjacent noncancerous tissues. While telomerase activity was not detected in any of 17 specimens of fibrocystic disease, surprisingly low levels of telomerase activity were detected in nine (45%) of 20 fibroadenomas. Among samples obtained by fine-needle aspiration, 14 (100%) of 14 patients whose fine-needle-aspirated specimen contained telomerase activity and who subsequently underwent surgery were confirmed to have breast cancer. Multivariate analysis of 125 specimens from patients for whom data were available on age at surgery, stage of disease, tumor size, lymph node status tumor histology, and menopausal status indicated that stage classification exhibited the strongest association with telomerase activity (for stage I versus stages II-IV: odds ratio = 1.0 versus 73.4; 95% confidence interval = 2.0-959.0; P = .02). CONCLUSION: Telomerase activity was detected in more than 95% of advanced stage breast cancers. It was absent in 19%-32% of less advanced cancers. Since a determination of any association between telomerase activity and patient survival is not possible at the present time, it remains to be determined whether lack of telomerase activity predicts for favorable outcome.

Neuroblastoma with DNA amplification and rearrangement in the N-myc gene region.

We detected a rearrangement in the N-myc gene region in a neuroblastoma from a 9-month-old girl. In this case, the N-myc gene was amplified 50-fold in the primary tumor, the lymph node metastasis, and the hepatic metastasis. The rearrangement was detected only in the primary tumor and the lymph node metastasis, whereas N-myc RNA and protein expression were detected only in the primary tumor and the hepatic metastasis. Both the rearranged N-myc gene and the normal N-myc gene were amplified 25-fold, and the rearrangement occurred 723 nucleotides downstream from the 3' end of exon 3. The cell line (NH-6) derived from the primary tumor showed N-myc gene amplification without this rearrangement. These results suggest the following: (a) the primary tumor had a least two clones; (b) the rearrangement interrupted N-myc gene expression; and (c) oncogenesis preceded N-myc gene amplification.

Telomerase activity is detected in pancreatic cancer but not in benign tumors.

Activation of telomerase and stabilization of telomeres are considered to be necessary for immortalization of human tumor cells. In the present study, telomerase activity was detected in 41 (95%) of 43 pancreatic cancer specimens but was detectable in none of 11 benign pancreatic tumors and only one of 3 pancreatitis samples. Low levels of telomerase activity were detected in 5 (14%) of 36 adjacent "normal" pancreatic tissues. These five telomerase-positive "normal" specimens were obtained from patients that also had pancreatic cancer and may reflect occult microinvasion. Telomerase activity was examined in 12 ex vivo brushing samples of the pancreatic duct, and 8 of 8 with pancreatic cancer had detectable telomerase activity, whereas 0 of 4 of benign lesions (cystadenoma and pancreatitis) did. These findings suggest that telomerase activity in cells derived from pancreatic ducts may be useful in the diagnosis of cancer and that telomerase activity may be a critical or rate-limiting step in pancreatic carcinogenesis.

Telomerase activity in gastric cancer.

Although many genetic alterations have been reported in gastric cancer, it is not known whether all gastric tumors are capable of indefinite proliferative potential, e.g., immortality. The expression of telomerase and stabilization of telomeres are concomitant with the attainment of immortality in tumor cells; thus, the measurement of telomerase activity in clinically obtained tumor samples may provide important information useful both as a diagnostic marker to detect immortal cancer cells in clinical materials and as a prognostic indicator of patient outcome. Telomerase activity was analyzed in 66 primary gastric cancers with the use of a PCR-based assay. The majority of tumors (85%) displayed telomerase activity, but telomerase was undetectable in 10 tumors (15%), 8 of which were early stage tumors. Most of the tumors with telomerase activity were large and of advanced stages, including metastases. Survival rate of patients of tumors with detectable telomerase activity was significantly shorter than that of those without telomerase activity. Alterations of telomere length (reduced/elongated terminal restriction fragments) were detected in 14 of 66 (21%) gastric cancers, and all 14 had telomerase activity. Cellular DNA contents revealed that all 22 aneuploid tumors had detectable telomerase activity. The present results indicate that telomerase activation may be required as a critical step in the multigenetic process of tumorigenesis, and that telomerase is frequently but not always activated as a late event in gastric cancer progression.

Alterations in telomeric repeat length in lung cancer are associated with loss of heterozygosity in p53 and Rb.

In the two-stage model of controlling cellular senescence in cultured human fibroblasts, retinoblastoma (Rb) and p53 proteins may be key factors regulating the mortality stage 1 mechanism. In addition, the critical loss of telomeric DNA due to the end-replication problem may result in the mortality stage 2 mechanism. Cells which acquire telomerase activity can overcome the M2 mechanism by stabilizing telomere length and thus become immortal (telomere hypothesis). At present it is known whether cellular immortality is a prerequisite for all human cancers. To investigate this question and the applicability of the two-stage model to human cancers, we analysed the relationship between alterations of telomere length and other genetic changes in lung cancer. Among 60 primary lung cancer tissues, telomere length alterations were observed in 16 tumors (26.7%) including 14 with short and two with elongated telomeres. Ten of them revealed allelic loss of both p53 and Rb genes, and remaining six showed no abnormalities in both genes. We propose that inactivation of both p53 and Rb genes may promote cell divisions causing telomere shortening in lung cancer as in the two-stage model, while there may be another pathway to overcome both M1 and M2 mechanisms, especially for adenocarcinoma.

Clinical investigation of neuroblastoma with partial deletion in the short arm of chromosome 1.

Several loci on the short arm of chromosome 1 (1p) have been reported as the consensus deleted regions for the putative suppressor genes of neuroblastoma by deletion mapping. The significance of deletion in 1p on the clinical features of neuroblastoma remains controversial. To clarify the relationship between the clinical features of neuroblastoma cases and genetic status of 1p, we performed deletion mapping on 1p on samples obtained from 58 cases with neuroblastoma using 12 highly polymorphic microsatellite or minisatellite loci. Loss of heterozygosity of 1p was detected in 19 cases (33%) of primary tumors and in 21 cases (36%) when metastatic and recurrent sites were included. They were classified into two groups according to the 1p deletion pattern: interstitial deletion (group I, n = 11) and terminal deletion (group T, n = 10). The shortest region of overlap in group I ranged between FGR and D1S170 (1p36.1-2). Clinically, all group I cases survived disease free, and none of these cases showed MYCN amplification. However, in group T, eight (80%) cases showed a large terminal deletion from D1S162 (1p32-pter), including the shortest region of overlap of group I, and two (20%) showed a very terminal deletion from D1S160 (1p 36.3). Of the group T cases, only two survived disease free, and seven (70%) showed MYCN amplification. Thus, the candidates for the locations of neuroblastoma suppressor genes on 1p may involve at least two regions, which demonstrate different clinical features.

High telomerase activity is an independent prognostic indicator of poor outcome in colorectal cancer.

Telomerase activity and altered telomere length have been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In the present study, we investigated telomerase activity and telomere length in colorectal cancers and noncancerous colonic mucosa specimens in 100 patients between 1991 and 1996. To determine whether the level of telomerase activity or telomere length is a prognostic indicator of patient outcome, we followed these patients more than 3 years after surgery. Among 100 primary colorectal cancer specimens, 96 specimens had telomerase activity. Because noncancerous mucosa has some detectable telomerase activity, we divided the levels of telomerase activity into three categories: high (>50-fold more than that in noncancerous mucosa); moderate (10- to 50-fold); and low (<10-fold) levels. Among 100 cancer tissues, 28 showed moderate telomerase activity and 44 showed high telomerase activity. The frequency of tumors with moderate or high telomerase activity showed no significant relationship with any clinicopathological factors. The prognosis of the patients with high telomerase activity was significantly worse than that for patients with moderate and low telomerase activity (P < 0.01). Among the 87 patients with curative surgery, disease-free survival rate of those with high telomerase activity was also significantly poorer (P < 0.01). These results indicate that a high level of telomerase activity may be an independent prognosis-predicting factor in the patients with colorectal cancer.

Rapid detection of MYCN gene amplification and telomerase expression in neuroblastoma.

Amplification of the MYCN gene and high telomerase activity predict a poor prognosis for the patients with neuroblastoma. We used PCR techniques for rapid detection of MYCN gene amplification and human telomerase reverse transcriptase (hTERT) expression in neuroblastoma specimens. The detection of MYCN gene amplification is based on differential PCR in which three primer pairs were used to coamplify a 178-bp fragment of target MYCN gene with two reference gene fragments, a 237-bp of p53 exon 7 and a 120-bp of beta-globin exon 3, in a single tube of 40 surgically resected tumor samples. MYCN amplification was identified by this differential PCR in all 10 samples carrying more than 10 copies (already known to have MYCN gene amplification by Southern blot analysis). There were no false-negative or false-positive cases, and the relative intensity of MYCN bands in the differential PCR correlated significantly with the copy number determined by Southern blot analysis (y = 0.99, P<0.0001). This protocol was also applicable in the biopsy or aspirated samples, as well as the paraffin-embedded tissues, and in detecting intratumoral heterogeneity. Using RT-PCR procedures, hTERT mRNA expression was detectable in all 13 tumors with high telomerase activity. These nonradioisotopic PCR-based protocols for detecting MYCN gene amplification and hTERT mRNA expression are rapid and reliable and are likely to be useful to determine the biological behavior of neuroblastoma.

Frequent deletions and mutations of the beta-catenin gene are associated with overexpression of cyclin D1 and fibronectin and poorly differentiated histology in childhood hepatoblastoma.

Hepatoblastoma (HBL) is the most common malignant liver tumor in young children. Recent reports have shown that the beta-catenin gene was frequently mutated or deleted in HBLS: To elucidate the role of beta-catenin abnormalities in HBLs, we searched for mutations of beta-catenin and APC as well as expression of the target genes, cyclin D1, c-myc, and fibronectin, in 68 primary HBLS: The mutation analysis revealed that 44 (65%) tumors carried missense mutations or deletions of beta-catenin, all of which were somatic and targeted to the exon 3 encoding the amino acid residues involved in its degradation. However, no loss of function mutation of the APC gene was detected by the yeast functional assay. Of interest, beta-catenin mutation was significantly correlated with overexpression of the target genes, cyclin D1 and fibronectin, but not with that of c-myc in HBLs as measured by quantitative real-time reverse transcription-PCR. The immunohistochemical studies in 15 HBLs demonstrated that the nuclear/cytoplasmic accumulation of beta-catenin was positive in 13 tumors, 9 of which had the deletion or mutation of the gene. The significant correlation between the beta-catenin gene abnormality and the positive staining of cyclin D1 was also confirmed. Furthermore, the nuclear accumulation of beta-catenin was strongly associated with the poorly differentiated tumor cell components as well as with the positive staining of cyclin D1 within the tumor. Thus, our present results suggested that the gain of function mutation of beta-catenin played a crucial role in the malignant progression of HBL in vivo.

Immunohistochemical detection of telomerase (hTERT) protein in human cancer tissues and a subset of cells in normal tissues.

We examined human telomerase reverse transcriptase (hTERT) protein distribution by immunohistochemistry in cultured cells and tissue sections. Cells with telomerase activity had nuclear positive signals whereas cells without telomerase activity did not. In most normal epithelial tissues, hTERT expression was prominent in the early proliferative descendent progenitors cells. In cancers with high telomerase activity, hTERT expression was detected in almost all neoplastic cells and correlated with telomerase activity levels, whereas cancers with low telomerase activity had fewer hTERT-positive cancer cells. In pediatric neuroblastomas with a favorable outcome, both the percentage of positive cells and the signal intensities of each hTERT-expressing cell decreased. These studies indicate that detection of telomerase at the cellular level is achievable and may have utility in cancer diagnostics.

Telomerase activity in neuroblastoma: is it a prognostic indicator of clinical behaviour?

Neuroblastomas show remarkable biological heterogeneity, resulting in favourable prognosis or unfavourable prognosis due to aggressive growth despite multimodal therapy. Recently, we proposed that aggressive tumours express telomerase at a high level while the favourable tumours lack or have low telomerase expression. To evaluate the correlation between telomerase activity and other biological characteristics reported as prognostic markers (MYCN gene amplification, loss of heterogeneity (LOH) in the short arm of chromosome 1, trk-A expression, Ha-ras p21 expression, and DNA ploidy), we investigated these biological features in 105 untreated neuroblastomas. In these cases, 23 showed high telomerase activity, 78 showed low activity, and telomerase activity was undetectable in 4 cases. Most tumours with genetic alterations (MYCN amplification or 1p32 LOH) showed high telomerase activity. Most tumours with low or undetectable activity were aneuploid, and showed trk-A and Ha-ras expression. Three of the four tumours with undetectable telomerase activity regressed. In 2 of the tumours with low telomerase activity, the residual tumours maturated and showed repression of telomerase activity. Thus, the level of telomerase activity correlated with other genetic alterations and/or gene expression and may be a useful prognostic indicator in neuroblastoma.