Maturation of mass-screened localized adrenal neuroblastoma

The prognostic role of 18F-FDG PET/CT-based response evaluation in children with stage 4 neuroblastoma

OBJECTIVES

To evaluate the association between metabolic response on 18F-FDG PET/CT and long-term survival in children with neuroblastoma (NB).

METHODS

A total of 39 consecutive children with newly diagnosed stage 4 NB undergoing both 18F-FDG PET/CT imaging at baseline and after chemotherapy were retrospectively analyzed. The associations between metabolic parameters, including SUVmax of the lesion with the most intense 18F-FDG uptake at baseline (SUVb), after chemotherapy (SUVe), and the percentage change between SUVb and SUVe, and long-term survival were evaluated.

RESULTS

With a median follow-up of 56 months, 22 patients who had achieved complete resolution on PET (no residual 18F-FDG uptake higher than the surrounding backgrounds) after chemotherapy had superior 5-year overall survival (OS) (73.6% vs. 39.0%, p = 0.044). SUVb > 6.9 indicated significantly poorer 5-year event-free survival (EFS) (12.5% vs. 59.3%, p = 0.005), as did SUVe > 1.2 (18.8% vs. 41.7%, p = 0.041). Children with SUVe > 1.2 had shorter 5-year OS (33.9% vs. 75.0%, p = 0.018). Multivariate analysis identified SUVe > 1.2 as an independent predictor for both EFS [hazard ratio (HR), 3.479, 95% CI, 1.381-8.761, p = 0.008] and OS (HR, 6.948, 95% CI, 1.663-29.025, p = 0.008), while SUVb > 6.9 was a predictor for EFS (HR, 2.889, 95% CI, 1.064-7.842, p = 0.037). Among 11 children with both SUVb > 6.9 and SUVe > 1.2, all experienced disease progression or relapse within 2 years since diagnosis.

CONCLUSION

18F-FDG PET/CT could be of useful to evaluate treatment response in children with stage 4 NB.

CLINICAL RELEVANCE STATEMENT

18F-FDG PET/CT after chemotherapy exhibits prognostic significance in neuroblastoma and holds potential as an alternative imaging modality for response evaluation, especially in cases with metaiodobenzylguanidine-nonavid or persistent avid disease.

KEY POINTS

The prognostic value of chemotherapy response on 18F-FDG PET/CT in advanced neuroblastoma is unknown. Higher 18F-FDG uptake after chemotherapy was associated with worse long-term event-free survival and overall survival. 18F-FDG PET/CT after chemotherapy holds prognostic significance in children with stage 4 neuroblastoma.

Bottom up proteomics identifies neuronal differentiation pathway networks activated by cathepsin inhibition treatment in neuroblastoma cells that are enhanced by concurrent 13-cis retinoic acid treatment

Neuroblastoma is the second most common pediatric cancer involving the peripheral nervous system in which stage IVS metastatic tumors regress due to spontaneous differentiation. 13-cis retinoic acid (13-cis RA) is currently used in the clinic for its differentiation effects and although it improves outcomes, relapse is seen in half of high-risk patients. Combinatorial therapies have been shown to be more effective in oncotherapy and since cathepsin inhibition reduces tumor growth, we explored the potential of coupling 13-cis RA with a cathepsin inhibitor (K777) to enhance therapeutic efficacy against neuroblastoma. Shotgun proteomics was used to identify proteins affected by K777 and dual (13-cis RA/K777) treatment in neuroblastoma SK-N-SH cells. Cathepsin inhibition was more effective in increasing proteins involved in neuronal differentiation and neurite outgrowth than 13-cis RA alone, but the combination of both treatments enhanced the neuronal differentiation effect. SIGNIFICANCE: As neuroblastoma can spontaneously differentiate, determining which proteins are involved in differentiation can guide development of more accurate diagnostic markers and more effective treatments. In this study, we established a differentiation proteomic map of SK-N-SH cells treated with a cathepsin inhibitor (K777) and K777/13-cis RA (dual). Bioinformatic analysis revealed these treatments enhanced neuronal differentiation and axonogenesis pathways. The most affected proteins in these pathways may become valuable biomarkers of efficacy of drugs designed to enhance differentiation of neuroblastoma [1].

Roles of PET/Computed Tomography in the Evaluation of Neuroblastoma

Neuroblastoma is one of the most common pediatric malignant tumors. Functional imaging plays an important role in the diagnosis, staging, and therapy response monitoring of neuroblastoma. Although metaiodobenzylguanidine scan with single-photon emission computed tomography/computed tomography remains the mainstay in functional imaging of the neuroblastomas, PET/CT has begun to show increased utility in this clinical setting.

Bottom up proteomics reveals novel differentiation proteins in neuroblastoma cells treated with 13-cis retinoic acid

Neuroblastoma, a cancer of the sympathetic nervous system, is the second most common pediatric cancer. A unique feature of neuroblastoma is remission in some patients due to spontaneous differentiation of metastatic tumors. 13-cis retinoic acid (13-cis RA) is currently used in the clinic to treat neuroblastoma due to its differentiation inducing effects. In this study, we used shotgun proteomics to identify proteins affected by 13-cis RA treatment in neuroblastoma SK-N-SH cells. Our results showed that 13-cis RA reduced proteins involved in extracellular matrix synthesis and organization and increased proteins involved in cell adhesion and neurofilament formation. These changes indicate that 13-cis RA induces tumor cell differentiation by decreasing extracellular matrix rigidity and increasing neurite overgrowth. Differentially-affected proteins identified in this study may be novel biomarkers of drug efficacy in the treatment of neuroblastoma. SIGNIFICANCE: As neuroblastoma can spontaneously differentiate, determining which proteins are involved in differentiation can guide development of novel treatments. 13-cis retinoic acid is currently used in the clinic as a differentiation inducer. Here we have established a proteome map of SK-N-SH cells treated with 13-cis retinoic acid. Bioinformatic analysis revealed the involvement of development, differentiation, extracellular matrix assembly, collagen biosynthesis, and neurofilament bundle association. This proteome map provides information as to which proteins are important for differentiation and identifies networks that can be targeted by drugs to treat neuroblastoma [1].

Metabolic characteristics of 13-cis-retinoic acid (isotretinoin) and anti-tumour activity of the 13-cis-retinoic acid metabolite 4-oxo-13-cis-retinoic acid in neuroblastoma

BACKGROUND AND PURPOSE

Isotretinoin (13-cis-retinoic acid; 13-cRA) is a differentiation inducer used to treat minimal residual disease after myeloablative therapy for high-risk neuroblastoma. However, more than 40% of children develop recurrent disease during or after 13-cRA treatment. The plasma concentrations of 13-cRA in earlier studies were considered subtherapeutic while 4-oxo-13-cis-RA (4-oxo-13-cRA), a metabolite of 13-cRA considered by some investigators as inactive, were greater than threefold higher than 13-cRA. We sought to define the metabolic pathways of 13-cRA and investigated the anti-tumour activity of its major metabolite, 4-oxo-13-cRA.

EXPERIMENTAL APPROACH

Effects of 13-cRA and 4-oxo-13-cRA on human neuroblastoma cell lines were assessed by DIMSCAN and flow cytometry for cell proliferation, MYCN down-regulation by reverse transcription PCR and immunoblotting, and neurite outgrowth by confocal microscopy. 13-cRA metabolism was determined using tandem MS in human liver microsomes and in patient samples.

KEY RESULTS

Six major metabolites of 13-cRA were identified in patient samples. Of these, 4-oxo-13-cRA was the most abundant, and 4-oxo-13-cRA glucuronide was also detected at a higher level in patients. CYP3A4 was shown to play a major role in catalysing 13-cRA to 4-oxo-13-cRA. In human neuroblastoma cell lines, 4-oxo-13-cRA and 13-cRA were equi-effective at inducing neurite outgrowth, inhibiting proliferation, decreasing MYCN mRNA and protein, and increasing the expression of retinoic acid receptor-β mRNA and protein levels.

CONCLUSIONS AND IMPLICATIONS

We showed that 4-oxo-13-cRA is as active as 13-cRA against neuroblastoma cell lines. Plasma levels of both 13-cRA and 4-oxo-13-cRA should be evaluated in pharmacokinetic studies of isotretinoin in neuroblastoma.

Expression of Wilms tumor gene in high risk neuroblastoma: complementary marker to tyrosine hydroxylase for detection of minimal residual disease

BACKGROUND

Neuroblastoma (NB) is an enigmatic tumor that often presents with metastatic disease at diagnosis and it is this aggressive propensity which places it among the deadliest pediatric tumors despite intensive multimodal therapy including hematopoietic stem cell transplantation (HSCT). We have previously demonstrated that Wilms tumor 1 gene (WT1) is a surrogate marker of proliferation in leukemia. To determine the potential association between WT1 and a known marker of NB, tyrosine hydroxylase (TH) in this high risk group of patients.

METHODS

A total of 141 random samples from 34 patients were obtained, at diagnosis (n=27), during therapy (n=95), in clinical remission (n=13), and at the time of relapse (n=6). Quantitative RT-PCR was used for the evaluation of the level of gene expression using specific primers.

RESULTS

Although similar gene expressions were demonstrated in both controls when evaluating both genes, significant difference was found at each clinical time point. Furthermore, when comparing patient samples from diagnosis to clinical remission and diagnosis to clinical relapse, individual gene expression varied. WT1 demonstrated significance (P=0.0002) and insignificance (P=0.06) whereas TH remained non-significant (P=0.2, P=0.09) respectively.

CONCLUSIONS

WT1 gene is indicative of cellular proliferation in NB and for this reason it can be adjuvant to TH for the detection minimal residual disease (MRD).

Long-term follow-up results of the observation program for neuroblastoma detected at 6-month mass screening

We conducted an observation program of neuroblastoma in infants, detected by mass screening at 6 months of age; we followed up with them for 15 years. No recurrence was observed after disappearance of tumors, and persistent tumors showed no malignant transformation or metastasis. Histology of the resected tumors showed age-related differentiation.

Presence of differentiating neuroblasts in bone marrow is a favorable prognostic factor for bone marrow metastatic neuroblastoma at diagnosis

Background

The prognostic impact of the presence of differentiating neuroblasts in bone marrow (BM) remains unclear in BM metastatic neuroblastoma (NB). We aimed to identify the prognostic impact of differentiating neuroblasts in BM at diagnosis and after chemotherapy.

Methods

A total of 51 patients diagnosed with BM metastatic NB at Asan Medical Center between January 1990 and July 2005 were enrolled. BM histology and laboratory data along with overall survival (OS) were compared with regard to the differentiation status of neuroblasts in BM at diagnosis and after chemotherapy.

Results

Among the 51 patients, 13 (25.5%) exhibited differentiating neuroblasts in BM at diagnosis and 17/51 (33.3%) exhibited them after chemotherapy. The only significant difference among patient groups was the improved OS in patients with differentiated neuroblasts in BM at diagnosis (P=0.021). In contrast, the differentiation status of neuroblasts in BM after chemotherapy did not affect OS (P=0.852).

Conclusions

Our study is the first report describing the presence of differentiating neuroblasts in BM. The presence of differentiating neuroblasts in BM at diagnosis may be a favorable prognostic factor for patients with BM metastatic NB; however, the same phenomenon after chemotherapy is irrelevant to prognosis.

Kidins220/ARMS depletion is associated with the neural-to Schwann-like transition in a human neuroblastoma cell line model

Peripheral neuroblastic tumors exist as a heterogeneous mixture of neuroblastic (N-type) cells and Schwannian stromal (S-type) cells. These stromal cells not only represent a differentiated and less aggressive fraction of the tumor, but also have properties that can influence the further differentiation of nearby malignant cells. In vitro neuroblastoma cultures exhibit similar heterogeneity with N-type and S-type cells representing the neuroblastic and stromal portions of the tumor, respectively, in behavior, morphology, and molecular expression patterns. In this study, we deplete kinase D-interacting substrate of 220kD (Kidins220) with an shRNA construct and thereby cause morphologic transition of the human SH-SY5Y neuroblastoma cell line from N-type to S-type. The resulting cells have similar morphology and expression profile to SH-EP1 cells, a native S-type cell line from the same parent cell line, and to SH-SY5Y cells treated with BrdU, a treatment that induces S-type morphology. Specifically, both Kidins220-deficient SH-SY5Y cells and native SH-EP1 cells demonstrate down-regulation of the genes DCX and STMN2, markers for the neuronal lineage. We further show that Kidins220, DCX and STMN2 are co-down-regulated in cells of S-type morphology generated by methods other than Kidins220 depletion. Finally, we report that the association of low Kidins220 expression with S-type morphology and low DCX and STMN2 expression is demonstrated in spontaneously occurring human peripheral neuroblastic tumors. We propose that Kidins220 is critical in N- to S-type transition of neural crest tumor cells.

Natural course of low risk neuroblastoma

BACKGROUND

Neuroblastoma is characterized by heterogeneity of histology, biology, and clinical behavior. Most epidemiology studies are based on Western and Japanese populations; there are very few studies on neuroblastoma from Southeast Asia.

PROCEDURE

Cases of Thai children with neuroblastoma were retrospectively reviewed to determine if the epidemiology of the disease differs from Western populations. Sixty-two cases were assembled from two pathology centers in Bangkok. Histologic prognostic category and MYCN copy number were determined.

RESULTS

The median age at diagnosis was 2.9 years. Only 11% of cases presented at less than 1 year of age and 12% cases had low stage disease (1, 2, and 4S). The majority of tumors had unfavorable histology (48/62); this was at least partly due to the higher age at diagnosis for most patients. MYCN amplification was detected in 18/52 (35%) tumors, all in stage 3 or 4 tumors. We assigned patients to high, intermediate and low risk categories using the Children's Oncology Group risk stratification criteria. In contrast to Western studies, the majority of cases (50/59 or 85%) in our series had high risk disease.

CONCLUSIONS

Since there is no evidence to date that the biology of neuroblastoma varies by geographic region, the paucity of low risk cases in our study may reflect spontaneous resolution/differentiation of tumors that are not clinically detected. Moreover, a delay in diagnosis of intermediate risk cases could result in higher tumor burden at the time of diagnosis, increasing the proportion of high risk cases observed.

High level of apoptosis and low AKT activation in mass screening as opposed to standard neuroblastoma

AIMS

Neuroblastoma is a paediatric solid tumour with a poor outcome except in children <1 year old. Based on catecholamine urinary excretion, mass screening (MS) programmes have been organized but failed to decrease the mortality of this tumour. To test the hypotheses of a spontaneous maturation/differentiation or regression, the levels of poly (ADP-ribose) polymerase (PARP)-1, an early apoptosis marker, of PhosphoAKT, a major apoptosis inhibitor, and of maturation/differentiation were compared in standard and in MS neuroblastomas.

METHODS AND RESULTS

We performed a case-control study of 55 primary tumours and 21 metastases of MS neuroblastomas. Matched controls were standard unscreened neuroblastomas and were paired according to age, stage, and MYCN amplification. The tumours were included in tissue microarrays. Immunohistochemical staining was performed using antibodies against, AKT, phosphoAKT, TRKB and PARP-1. The expression of PARP-1 and that of phosphoAKT were significantly higher in standard than in MS neuroblastomas independently of age and stage of the tumour. PhosphoAKT and PARP-1 expression was significantly correlated in both tumours.

CONCLUSIONS

These data suggest that the better prognosis of patients with MS neuroblastomas compared with classical neuroblastomas was secondary to spontaneous tumour regression mediated by higher levels of apoptosis associated with low activation of AKT.

Adrenal ganglioneuromas: incidentalomas with misleading clinical and imaging features

BACKGROUND

Ganglioneuromas are benign neoplasms of the neural crest, occurring rarely in the adrenal glands. This study presents our experience regarding diagnostic and therapeutic management of these neoplasms and a review of the relevant literature.

METHODS

Among 150 patients with of incidentalomas, we had 7 primary ganglioneuromas. Their clinical, imaging, and operative data were collected retrospectively, and the literature was reviewed using MEDLINE. There were 4 females and 3 males, with mean age of 50 years (range, 39-64). All neoplasms were discovered incidentally with ultrasonography and were evaluated subsequently with computed tomography (CT). One patient was studied further with (131)I-MIBG due to asymptomatic increased in urine vanillylmandelic acid, and 1 patient with history of breast cancer underwent additional FDG-PET/CT.

RESULTS

All but 2 patients were asymptomatic. Two patients complained of epigastric pain and hypertension, respectively. The preoperative mean size on CT was 6.8 cm, whereas the postoperative true mean histologic size was 7.7 cm. Both patients who were evaluated with radionuclide studies had false positive results, suggestive of pheochromocytoma and adrenal metastasis, respectively. Three patients underwent open adrenalectomy due to preoperative suspicion of carcinoma, and the remaining 4 underwent laparoscopic anterior adrenalectomy. Histologically, all 7 neoplasms were completely differentiated, mature ganglioneuromas. We had no mortality or significant morbidity. No recurrence occurred during a mean follow-up of 6 years (range, 1-18).

CONCLUSION

Adrenal ganglioneuromas are rare incidentalomas that can mimic primary or secondary adrenal malignancies as well as pheochromocytomas. Despite their usually large size, resection via laparoscopic approach is safe and effective.

A prospective study of a long-term follow-up of an observation program for neuroblastoma detected by mass screening

BACKGROUND

A nationwide mass screening for neuroblastoma (NBL) in 6-month-old infants (MS6M) was performed in Japan from 1985 to 2003. Favorable biological features were identified for most of the detected tumors; consequently, we began an observation program for selected screened patients in 1993. Here, we report the clinicopathological findings and present status of patients enrolled in our observation program, with the goal of evaluating its usefulness.

PROCEDURE

Between 1993 and 2003, 53 of 101 patients with NBL detected by MS6M were enrolled. The patients were divided into four groups according to changes in urinary VMA and HVA levels and tumor size.

RESULTS

Urinary VMA and HVA levels decreased in 39 of 53 patients. In 17 of these 39 patients, the tumor became undetectable (Group A); in 22 patients the tumor was detectable (Group B). In seven patients, tumor marker levels varied, and tumor volume gradually increased (Group C). In six patients, tumor marker levels and tumor volume increased in the short term (Group D). One patient had multiple tumors (1M according to International Neuroblastoma Staging System). All tumors in Groups C and D, four tumors in Group B, and one tumor in the 1M patient were removed. No unfavorable biologic factors were noted in any excised tumor.

CONCLUSIONS

The observation program of the present study, one of the largest series for MS6M, confirmed that over 70% of patients who fulfilled the criteria could be observed without surgery.

Sporadic synchronous ganglioneuromas in a child--case report and review

An 8-year-old girl presented with a relatively asymptomatic abdominopelvic mass that was detected in the neonatal period. She harbored a presacral mass with intraspinal extension and a right posterior mediastinal mass; all were excised completely and were ganglioneuromas. The report discusses the maturation of neuroblastoma-ganglioneuromas and details the staged management of sporadic synchronous ganglioneuromas in a child, probably the first in published English literature.

The laparoscopic approach of neuroblastoma

Neuroblastoma is one of the most common solid tumors, and the biopsy and excision of this tumor are often required as part of a planned multimodal treatment. In 1995, Holcomb and coworkers first reported endosurgical procedures for the diagnosis and treatment of pediatric malignancies; however, the usefulness of laparoscopic procedures for abdominal neuroblastoma is still unclear. Twenty-five laparoscopic biopsies for advanced abdominal neuroblastoma and nine laparoscopic excisions for localized abdominal neuroblastoma performed at Saitama Children's Medical Center were evaluated. The laparoscopic procedures significantly reduce the time to start postoperative feeding as well as the time to start postoperative chemotherapy and the duration of hospital stay. Also, the blood loss of laparoscopic excision of localized neuroblastoma was significantly little compared with that of open excision. Precise indications of laparoscopic procedure for the diagnosis and treatment of abdominal neuroblastoma provide better prognosis and quality of life for infants and children.

Nine cases of childhood adrenal tumour presenting with hypertension and a review of the literature

AIM

To describe the clinical features, treatment and outcome of children adrenal tumors presenting with hypertension.

METHODS

The records of nine children under 16 years of age with adrenal tumours presenting with hypertension were analysed. Details were recorded for family history, clinical presentation, biochemistry, imaging, histology, treatment and outcome.

RESULTS

Abdominal mass was palpable only in one patient at diagnosis. Besides hypertension-associated symptoms, Cushing's syndrome was the common presentation form (n = 4). Abdominal computed topography showed adrenal mass in all patients. Tumours were completely resected for each patient. The median tumour weight was 73 g (11-530 g) and the size ranged from 1.5 x 1.5 to 12 x 14 cm2. Pheochromocytoma (n = 2), adrenocortical adenoma (n = 3), adrenocortical carcinoma (n = 1), neuroblastoma (n = 2) and ganglioneuromas (n = 1) were found. In one case, adrenal pheochromocytoma first occurred and non-functioning islet cell tumour successively occurred at pancreas. A better status is common at a median follow-up time of 3.5 years.

CONCLUSIONS

Childhood adrenal tumours presented with hypertension showed an atypical course, variable presentation. We report a unique case of adrenal pheochromocytoma followed by the occurrence of non-functioning islet cell tumour. Reversal of hypertension by surgery is crucial. Imaging techniques are important to detect adrenal tumours.

Ganglioneuroma of small bowel mesentery presenting as acute abdomen

Ganglioneuroma is a rare benign tumor, usually seen in children and young adults, arising in the central nervous system. Ganglioneuroma of the mesentery is extremely rare; only one case has been recorded. We report the second case of a primary mesentery ganglioneuroma. The patient underwent surgical intervention for diagnostic and therapeutic purposes.

Differential Expression of Neuronal Genes Defines Subtypes of Disseminated Neuroblastoma with Favorable and Unfavorable Outcome

PURPOSE

Identification of molecular characteristics of spontaneously regressing stage IVS and progressing stage IV neuroblastoma to improve discrimination of patients with metastatic disease following favorable and unfavorable clinical courses.

EXPERIMENTAL DESIGN

Serial analysis of gene expression profiles were generated from five stage IVS and three stage IV neuroblastoma. Differential expression of candidate genes was evaluated by real-time quantitative reverse transcription-PCR in 76 pretreatment tumor samples (stage IVS n=27 and stage IV n=49). Gene expression-based outcome prediction was determined by Prediction Analysis for Microarrays using 38 tumors as a training set and 38 tumors as a test set.

RESULTS

Comparison of serial analysis of gene expression profiles from stage IV and IVS neuroblastoma revealed approximately 500 differentially expressed transcripts. Genes related to neuronal differentiation were observed more frequently in stage IVS tumors as determined by associating transcripts to Gene Ontology annotations. Forty-one candidate genes were evaluated by quantitative reverse transcription-PCR and 18 were confirmed to be differentially expressed (P<or=0.001). Classification of patients according to expression patterns of these 18 genes using Prediction Analysis for Microarrays discriminated two subgroups with significantly differing event-free survival (96+/-6% versus 40+/-8% at 3 years; P<0.0001) and overall survival (100% versus 72+/-7% at 3 years; P=0.0003). This classifier was the only independent covariate marker in a multivariate analysis considering the variables stage, age, MYCN amplification, and gene signature.

CONCLUSIONS

Spontaneously regressing and progressing metastatic neuroblastoma differ by specific gene expression patterns, indicating distinct levels of neuronal differentiation and allowing for an improved risk estimation of children with disseminated disease.

Treatment Complications in Children Diagnosed With Neuroblastoma During a Screening Program

Purpose

The Québec Neuroblastoma Screening Program was put in place to investigate the possibility of decreasing mortality from high-risk neuroblastoma through early screening. We assess treatment complications in the patients diagnosed during this screening program.

Patients and Methods

A total of 476,603 patients born during the screening period were eligible. Parents of 425,838 children (89%) agreed to participate in the 3-week screening, and 73% agreed to participate in the 6-month screening. Forty-five patients had neuroblastoma. We reviewed the medical and research charts for all patients diagnosed by screening. Follow-up was available from 8 to 13 years after screening.

Results

Forty-five patients were diagnosed by screening. All patients were treated according to the Pediatric Oncology Group recommendations of the time. All patients had surgery, and 29 patients received chemotherapy. No patient died from neuroblastoma. Eleven patients suffered complications from treatment. Two patients had life-threatening complications.

Conclusion

In view of the lack of impact of screening programs on neuroblastoma mortality, evidence that many of the tumors detected through screening can be observed without treatment and the serious complications that may arise from therapy, we do not support neuroblastoma screening programs for children.

Increased occurrence of caspase-dependent apoptosis in unfavorable neuroblastomas

Neuroblastoma frequently shows spontaneous regression in which two distinct types of programmed cell death, ie, caspase-dependent apoptosis and H-Ras-mediated autophagic degeneration, have been suggested to play a key role. The current study was conducted to determine which of these cell suicide pathways predominated in this tumor regression. Periodic acid-Schiff (PAS) staining and immunostaining for H-Ras and for the full-length and cleaved forms of caspase-3, poly (ADP-ribose) polymerase (PARP), and lamin A were carried out on 55 archival tumor specimens. The incidence of caspase-dependent apoptosis in each tumor was quantified by cleaved lamin A staining and compared with clinicopathologic prognostic factors. Although a recent report has shown that neuroblastic cells undergoing autophagic degeneration were readily detectable by PAS and H-Ras staining, we could not confirm this result in any of our samples with the exception of one tumor. Instead, many of our neuroblastoma samples showed nonspecific PAS and Ras staining in areas of necrosis, suggesting that autophagic "degeneration" indeed corresponds to coagulation necrosis or oncosis. Unexpectedly, the incidence of caspase-dependent apoptosis was significantly correlated with indicators of a poor prognosis in these tumors, including Shimada's unfavorable histology, MYCN amplification, and a higher mitosis-karyorrhexis index, but not with factors related to tumor regression such as clinical stage and mass screening. These results indicate that neither caspase-dependent apoptosis nor autophagic "degeneration" may be involved in spontaneous neuroblastoma regression. This suggests that other mechanisms, perhaps such as tumor maturation, may be responsible for this phenomenon.

Autocrine proliferation of neuroblastoma cells is partly mediated through neurokinin receptors: relevance to bone marrow metastasis

Despite intensive therapy, approximately 60-80% of children who are diagnosed with metastatic neuroblastoma (NB) succumb to the disease. NB preferentially metastasizes to the bone marrow (BM). In the present study we used SY5Y and CHP212 (NB cell lines) to study the roles of the preprotachykinin-I (PPT-I) gene and the natural receptors for PPT-I peptides, neurokinin-1 (NK-1) and NK-2, in the biology of NB. PPT-I, NK-1 and NK-2 were constitutively expressed in the NB cells. Functional studies, with specific NK receptor antagonists, showed that PPT-I peptides mediate autocrine proliferation of the NB cells through both NK-1 and NK-2 receptors. Full-length and truncated NK-1 receptors were detected in NB cells. Since there is one copy of the NK-1 gene, we used NK-1-specific siRNA to suppress the expression of NK-1. The NK-1-deficient NB cells showed phenotypes consistent with cell differentiation. Suppression of NK-1 did not appear to cause cell death, as demonstrated by trypan blue exclusion and by undetectable active caspase. NK-1 suppression reduced the proliferation of the NB cells beginning by 10-fold at day 1 and reached a 10(5)-fold reduction by day 10. The NK-1 deficient cells did not proliferate when they were placed as cocultures with BM stroma, which suggests that NK-1 signaling is important for the survival of NB cells in the BM. The results show potential roles for NK receptors in the proliferation of NB.

Cutaneous ganglioneuroma within a giant congenital nevus

Cutaneous ganglioneuroma has only occasionally been reported in the literature. Cutaneous ganglioneuroma is seen even more rarely in association with a giant congenital nevus. Differential diagnosis includes malignancies, especially melanoma and metastatic neuroblastoma. It is essential to rule out malignancy in a solid lesion within a congenital nevus. The present report is possibly the first relating ganglioneuroma and a congenital nevus to a cervical mass detected during routine prenatal ultrasound.

Genome-wide analysis of gene expression in neuroblastomas detected by mass screening

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood and the third most common pediatric cancer. Although numerous factors including patient age, disease stage and genetic abnormalities have been shown to be predictive of outcome, the mechanisms responsible for the highly variable clinical behavior of this tumor remain largely unknown. In order to gain new insights into the biology of this tumor, we performed microarray analysis and compared the gene expression patterns of NB detected by mass screening, characterized by highly probable spontaneous regression, versus stage 4 NB with poor prognosis. The bioinformatics analysis revealed a set of 19 discriminatory genes that may play a significant role in the natural progression of the disease. Validation of these results and further mechanistic studies would shed new light on the biology of tumor progression, and provide new tools to predict clinical outcome in children with NB.