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R C Seeger

Publications and source records attributed to R C Seeger.

At least 37 records · Page 2Linked to original sources
PubMed2000

Telomerase activity by TRAP assay and telomerase RNA (hTR) expression are predictive of outcome in neuroblastoma.

BACKGROUND: Recent studies have associated telomerase with prognostic factors and survival in neuroblastoma. PROCEDURE: We examined telomerase activity by telomere repeat amplification protocol (TRAP) and expression of the RNA component of telomerase (hTR) by Northern blotting in 106 primary neuroblastoma tumors and 22 established cell lines. RESULTS: Overall survival at 5 years for all 106 tumors was significantly better for patients with undetectable TRAP (75% vs. 59%; P = 0.03) or low hTR expression (84% vs. 43%; P < 0.0001), and especially for patients whose tumors had both low hTR expression and undetectable TRAP (all patients, 91% vs. 54%, P = 0.0002; for 17 stage IV-S tumors, 100% vs. 72%, P = 0.04). Strong expression of hTR was seen in 22 cell lines from aggressive tumors, and all maintained telomere length, but 3/22 were TRAP negative. CONCLUSIONS: These data suggest that both hTR expression and telomerase activity via the TRAP assay should be performed concurrently to predict survival in neuroblastoma patients, particularly in stage 4-S.

Child↗
PubMed2000

Neutrophils are cytotoxic and growth-inhibiting for neuroblastoma cells with an anti-GD2 antibody but, without cytotoxicity, can be growth-stimulating.

Neutrophils and mononuclear cells (MNC) can mediate antibody-dependent cellular cytotoxicity (ADCC) against cancer cells. To study cytotoxicity and growth inhibition of neuroblastoma cells by neutrophils and MNC with chimeric anti-disialoganglioside (GD2) monoclonal antibody (mAb) ch14.18, we developed digital image microscopy scanning (DIMSCAN) assays that measure fluorescence of target cells in 96-well plates after 6-18 h (cytotoxicity assay) or 7 days (growth assay). Neuroblastoma cell lines (GD2-positive: SMS-KCN, SMS-LHN, LA-N-1; GD2-negative: SK-N-SH) were preloaded with calcein acetoxymethyl ester for the cytotoxicity assay or labeled in situ after 7 days of culture with fluorescein diacetate in the growth assay. Fluorescence, as quantified by DIMSCAN, was correlated with neuroblastoma cell number in both assays (100-2000 cells/well). In the cytotoxicity test, both neutrophils and MNC effectively mediated ADCC of GD2-positive but not GD2-negative neuroblastoma cell lines. Cytotoxicity of both neutrophils and MNC increased with effector to target cell (E:T) ratio (5-50:1) and mAb ch.14.18 dose (0.1-10 microg/ml). ADCC of neutrophils, but not MNC, increased with addition of GM-CSF. Neutrophils, especially with rhGM-CSF, significantly suppressed growth of GD2-positive cell lines at a high E:T ratio (50:1) and mAb dose (10 microg/ml). Without antibody, neutrophils inhibited growth of one cell line (LA-N-1) but stimulated growth of two others (SMS-KCN, SMS-LHN). If neuroblastoma cells did not express GD2 (SK-N-SH), neutrophils stimulated growth whether or not antibody was present. Neutrophil culture supernatants increased growth of SK-N-SH, LA-N-1, and SMS-KCN cells, and MNC culture supernatants increased growth of SK-N-SH. In conclusion, neutrophils can mediate cytotoxicity and growth inhibition with a chimeric anti-GD2 antibody but also can promote tumor cell growth if antibody is not present or if GD2 is not expressed.

Antibodies, Monoclonal↗
PubMed2000

Biologic variables in the outcome of stages I and II neuroblastoma treated with surgery as primary therapy: a children's cancer group study.

PURPOSE: To determine prospectively whether surgery alone is sufficient therapy for Evans stages I and II neuroblastoma and to define biologic and clinical features having prognostic potential for this group. PATIENTS AND METHODS: Between June 1989 and August 1995, 374 eligible children (age range, 0 to 18 years) with newly diagnosed stage I (n = 141) and stage II (n = 233) neuroblastoma were registered onto Children's Cancer Group trial 3881. Surgical resection was the only primary therapy except in cases with spinal cord compression, where radiation therapy was allowed. Event-free survival (EFS) and overall survival (OS) were analyzed by life-table methods according to clinical and biologic features. RESULTS: EFS and OS (mean +/- SE) for all stage I patients were 93% +/- 3.0% and 99% +/- 1.0%, respectively, compared with 81% +/- 4.0% and 98% +/- 2. 0%, respectively, for stage II patients. The significantly higher recurrence rate among stage II patients was managed successfully in 38 of 43 children with either surgery or multimodality treatment. There was one death among stage I patients and six among stage II. For stage II patients tumor MYCN gene amplication, unfavorable histopathology, an age greater than 2 years, and positive lymph nodes predicted a lower OS (P <.05). CONCLUSION: Children with stages I and II neuroblastoma have 98% survival with surgery alone as primary therapy. Supplemental treatment was necessary in only 10% of stage I patients and 20% of stage II patients. In children with localized neuroblastoma, a subset of patients that are at higher risk for death can be defined as those with stage II disease who have tumor MYCN amplification or who are >/= 2 years of age with either unfavorable histopathology or positive lymph nodes.

Adolescent↗
PubMed2000

Favorable biology and outcome of stage IV-S neuroblastoma with supportive care or minimal therapy: a Children's Cancer Group study.

PURPOSE: Stage IV-S neuroblastoma is a metastatic disease associated with spontaneous regression and good survival, but 10% to 20% of infants die from early complications. The purpose of this study was to evaluate outcome and prognostic factors in infants with stage IV-S neuroblastoma treated prospectively with supportive care only or, in symptomatic patients, with low-dose cytotoxic therapy. PATIENTS AND METHODS: Eighty eligible infants were studied for response and survival with supportive care or, for symptomatic patients, cyclophosphamide 5 mg/kg/d for 5 days with or without hepatic radiation of 4.5 Gy over 3 days. Staging was reviewed centrally, and MYCN gene copy number, Shimada histopathologic classification, serum ferritin levels, and bone marrow immunocytology were determined. RESULTS: Stage IV-S and International Neuroblastoma Staging System stage 4S were 98% concordant. MYCN was not amplified in any of the tumors tested (n = 58), and Shimada histopathologic classification was favorable in 96% (n = 68/71). The 5-year event-free survival (EFS) rate for all infants was 86% and the survival rate was 92%. Supportive care was the only treatment provided for 44 (55%) of 80 infants, and their 5-year survival rate was 100%, compared with 81% survival for those requiring cytotoxic therapy for symptoms (P =.005). Five of six deaths were in infants younger than 2 months of age at diagnosis and were due to complications of extensive abdominal involvement with respiratory compromise or disseminated intravascular coagulation. Although age </= 3 months at diagnosis was significant for EFS (P =. 043), it was less significant for survival (P =.077). The only other significant factor predictive for improved survival was favorable Shimada histopathologic classification. Sites of metastatic involvement (liver, skin, or bone marrow) and surgical resection of the primary tumor were not significant for survival. CONCLUSION: This study confirms the favorable biologic features and excellent survival of infants with stage IV-S neuroblastoma with minimal therapy. Infants younger than 2 months old at diagnosis with rapidly progressive abdominal disease may benefit from earlier and more intensive treatment.

Adrenal Gland Neoplasms↗
PubMed2000

Biologic factors determine prognosis in infants with stage IV neuroblastoma: A prospective Children's Cancer Group study.

PURPOSE: A prospective Children's Cancer Group study, CCG-3881, has been completed to determine if a more accurate prediction of prognosis by biologic features can identify subgroups of infants with stage IV neuroblastoma (NBL) who require differing intensities of treatment. PATIENTS AND METHODS: One hundred thirty-four infants were registered from June 1989 to August 1995, with a median follow-up of 47.1 months (range, 0 to 88 months). The biologic factors examined were tumor MYCN copy number, Shimada histopathologic classification, serum ferritin, and bone marrow immunocytology (sensitivity, one tumor cell per 10(5) bone marrow cells). Patients treated on CCG-3881 (n = 116) received four-drug chemotherapy for 9 months (cisplatin, cyclophosphamide, doxorubicin, and etoposide), with surgery and local radiation to residual disease. After January 1991, all subsequent infants with tumor MYCN amplification (n = 18) were transferred after one cycle of therapy to the high-risk CCG-3891 protocol (open January 1991 to April 1996) for more intensive treatment. RESULTS: The 3-year event-free survival (EFS) and overall survival (mean +/- SD) for the 134 infants were 63% +/- 5% and 71% +/- 5%, respectively. Patients whose tumors were without MYCN amplification had a 93% +/- 4% 3-year EFS, whereas those with amplified MYCN had a 10% +/- 7% 3-year EFS (P <. 0001). Each of the other biologic features studied had prognostic significance in univariate analysis but not after stratifying by MYCN copy number. CONCLUSION: Infants less than 1 year of age at diagnosis with stage IV NBL have a much improved outcome compared with children >/= 1 year of age. Nonamplified MYCN tumors identify a group of infants with a 93% +/- 4% EFS, whereas amplified MYCN copy number clearly identifies patients who are unlikely to survive despite intensive chemotherapy.

Biological Factors↗
PubMed2000

Loss of heterozygosity at 1p36 independently predicts for disease progression but not decreased overall survival probability in neuroblastoma patients: a Children's Cancer Group study.

PURPOSE: To determine the independent prognostic significance of 1p36 loss of heterozygosity (LOH) in a representative group of neuroblastoma patients. PATIENTS AND METHODS: Diagnostic tumor specimens from 238 patients registered onto the most recent Children's Cancer Group phase III clinical trials were assayed for LOH with 13 microsatellite polymorphic markers spanning chromosome band 1p36. Allelic status at 1p36 was correlated with other prognostic variables and disease outcome. RESULTS: LOH at 1p36 was detected in 83 (35%) of 238 neuroblastomas. There was a correlation of 1p36 LOH with age at diagnosis greater than 1 year (P = .026), metastatic disease (P<.001), elevated serum ferritin level (P<.001), unfavorable histopathology (P<.001), and MYCN oncogene amplification (P<.001). LOH at 1p36 was associated with decreased event-free survival (EFS) and overall survival (OS) probabilities (P<.0001). For the 180 cases with single-copy MYCN, 1p36 LOH status was highly correlated with decreased EFS (P = .0002) but not OS (P = .1212). Entering 1p36 LOH into a multivariate regression model suggested a trend toward an independent association with decreased EFS (P = .0558) but not with decreased OS (P = .3687). Furthermore, allelic status at 1p36 was the only prognostic variable that was significantly associated with decreased EFS in low-risk neuroblastoma patients (P = .0148). CONCLUSION: LOH at 1p36 is independently associated with decreased EFS, but not OS, in neuroblastoma patients. Determination of 1p36 allelic status may be useful for predicting which neuroblastoma patients with otherwise favorable clinical and biologic features are more likely to have disease progression.

Child↗
PubMed2000

Expression of protein gene product 9.5 and tyrosine hydroxylase in childhood small round cell tumors.

Small round cell tumors of childhood can be histologically ambiguous, can require tumor markers for an accurate diagnosis, and include neuroblastoma, peripheral primitive neuroectodermal tumor (pPNET), Ewing's sarcoma (ES), lymphoma, and rhabdomyosarcoma. Because the cell type of origin for ES remains controversial, characterizing gene expression in ES can provide diagnostic markers and lead to better understanding of tumor biology. We studied RNA expression of the neuronal genes protein gene product 9.5 (PGP 9.5) and tyrosine hydroxylase (TH) by Northern analysis in cell lines and tissue from small round cell tumors. PGP 9.5 showed strong expression in 17 of 17 neuroblastoma cell lines, 9 of 9 pPNET cell lines, and 11 of 11 ES cell lines. PGP 9.5 was weakly expressed in 1 of 1 alveolar rhabdomyosarcoma cell lines but not in 1 of 1 embryonal rhabdomyosarcomas, and weak expression was seen in 1 of 7 leukemia cell lines. In tumor tissue, all 12 neuroblastomas expressed PGP 9.5, as did all 7 pPNET and all 7 ES. PGP 9.5 was very weakly expressed in 6 of 9 rhabdomyosarcomas and 1 of 9 lymphomas. TH was expressed only in neuroblastomas, and no TH expression was seen in cell lines or tissue from other tumors. As high expression of PGP 9.5 was only found in neural tumors; PGP 9.5 expression by ES provides further evidence for a neural origin of this tumor, whereas TH expression is highly specific for neuroblastomas. PGP 9.5 expression should allow sensitive detection of minimal residual disease for ES and pPNET using reverse transcription-PCR, and the variability in TH and PGP 9.5 expression levels in neuroblastomas indicates that expression of both genes should be used for monitoring minimal residual disease by reverse transcription-PCR.

Adolescent↗
PubMed2000

Parental smoking and alcohol consumption and risk of neuroblastoma.

Previous studies and animal evidence have suggested a relationship between parental tobacco or alcohol use and the risk of some childhood cancers, including neuroblastoma. A case-control study was conducted to investigate the relationship between parental tobacco smoking, alcohol consumption, and risk of neuroblastoma. Cases were children diagnosed with neuroblastoma over the period 1992-1994 at Children's Cancer Group and Pediatric Oncology Group institutions throughout the United States and Canada. One matched control was selected using random-digit dialing. Information on parental smoking and drinking history was obtained from 504 case and 504 control parents by telephone interview. Overall, there was no consistent pattern of association with parental smoking and alcohol consumption. For example, both maternal smoking and drinking during the period from 1 month before pregnancy through breastfeeding had adjusted odds ratios (ORs) of 1.1 [95% confidence interval (CI), 0.8-1.4]. There was no association with paternal smoking (OR, 1.2; 95% CI, 0.8-1.6) or paternal drinking 1 month before conception (OR, 1.0; 95% CI, 0.7-1.4). There was no consistent increase in risk by the amount of smoking or drinking during any time period relative to pregnancy. There was no suggestion of an increased risk when only one parent smoked. Smoking or drinking among both parents did not jointly increase the risk of neuroblastoma in their offspring. The child's age at diagnosis, stage, or MYCN oncogene amplification status did not materially alter the OR estimates. It is concluded that the results from this study do not indicate any evidence for a relationship between neuroblastoma and parental tobacco or alcohol use.

Adolescent↗
PubMed1999

Hormone and fertility drug use and the risk of neuroblastoma: a report from the Children's Cancer Group and the Pediatric Oncology Group.

Previous epidemiologic studies have suggested an association between maternal sex hormone use during pregnancy, including infertility medication, and an increased risk of neuroblastoma in the offspring. The authors conducted a case-control interview study from 1992 to 1996 that included 504 children less than 19 years of age whose newly diagnosed neuroblastoma was identified by two national collaborative clinical trials groups in the United States and Canada, the Children's Cancer Group and the Pediatric Oncology Group. Controls, matched to cases on age, were identified by random digit dialing. No association was found for use of oral contraceptives before or during pregnancy (first trimester odds ratio (OR) = 1.0, 95% confidence interval (CI): 0.5, 2.1). The odds ratio was slightly elevated for history of infertility (OR = 1.4, 95% CI: 0.9, 2.1) and ever use of any infertility medication (OR = 1.2, 95% CI: 0.7, 2.2). Specifically, ever use of clomiphene was associated with a 1.6-fold increased risk (95% CI: 0.8, 3.0) but not periconceptionally or during the index pregnancy. A suggestive pattern was found for gender of the offspring, with an increased risk for males but not for females after exposure to oral contraceptives or clomiphene. This study did not find consistent and large increased risks for maternal use of hormones, but the suggestion of an association for male offspring requires further consideration.

Adult↗
PubMed1999

Treatment of high-risk neuroblastoma with intensive chemotherapy, radiotherapy, autologous bone marrow transplantation, and 13-cis-retinoic acid. Children's Cancer Group.

BACKGROUND: Children with high-risk neuroblastoma have a poor outcome. In this study, we assessed whether myeloablative therapy in conjunction with transplantation of autologous bone marrow improved event-free survival as compared with chemotherapy alone, and whether subsequent treatment with 13-cis-retinoic acid (isotretinoin) further improves event-free survival. METHODS: All patients were treated with the same initial regimen of chemotherapy, and those without disease progression were then randomly assigned to receive continued treatment with myeloablative chemotherapy, total-body irradiation, and transplantation of autologous bone marrow purged of neuroblastoma cells or to receive three cycles of intensive chemotherapy alone. All patients who completed cytotoxic therapy without disease progression were then randomly assigned to receive no further therapy or treatment with 13-cis-retinoic acid for six months. RESULTS: The mean (+/-SE) event-free survival rate three years after the first randomization was significantly better among the 189 patients who were assigned to undergo transplantation than among the 190 patients assigned to receive continuation chemotherapy (34+/-4 percent vs. 22+/-4 percent, P=0.034). The event-free survival rate three years after the second randomization was significantly better among the 130 patients who were assigned to receive 13-cis-retinoic acid than among the 128 patients assigned to receive no further therapy (46+/-6 percent vs. 29+/-5 percent, P=0.027). CONCLUSIONS: Treatment with myeloablative therapy and autologous bone marrow transplantation improved event-free survival among children with high-risk neuroblastoma. In addition, treatment with 13-cis-retinoic acid was beneficial for patients without progressive disease when it was administered after chemotherapy or transplantation.

Adolescent↗
PubMed1999

Allelic deletion at 11q23 is common in MYCN single copy neuroblastomas.

Deletions of the long arm of chromosome 11 (11q) have been noted in primary neuroblastomas, but a comprehensive analysis has not been performed. Therefore, we analysed 331 neuroblastomas (295 sporadic, 15 familial and 21 tumor-derived cell lines) to determine the prevalence of 11q allelic deletions, to map the location of a putative tumor suppressor gene and to perform clinical correlative studies. Assays for loss of heterozygosity (LOH) were performed at 24 microsatellite loci spanning 11q. LOH was observed at multiple 11q loci in 129/295 (44%) sporadic neuroblastomas, 5/15 (33%) familial neuroblastomas, and 5/21 (24%) neuroblastoma cell lines. A single region of 2.1 cM within 11q23.3, flanked by markers D11S1340 and D11S1299, was deleted in all specimens with 11q LOH. Allelic loss at 11q23 was inversely related to MYCN amplification (P<0.001). Within the subset of cases with a single copy of MYCN, 11q LOH was associated with advanced stage disease (P=0.008), unfavorable histopathology (P=0.042), and decreased overall survival probability (P=0.008). However, 11q LOH was not independently prognostic in multivariate analyses. These data support the hypothesis that a tumor suppressor gene mapping within 11q23.3 is commonly inactivated during the malignant evolution of a large subset of neuroblastomas, especially those with unamplified MYCN.

Alleles↗
PubMed1999

Increase of ceramide and induction of mixed apoptosis/necrosis by N-(4-hydroxyphenyl)- retinamide in neuroblastoma cell lines.

BACKGROUND: The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4-HPR or fenretinide) is toxic to myeloid leukemia and cervical carcinoma cell lines, probably in part due to its ability to increase levels of reactive oxygen species (ROS). We have studied the effects of 4-HPR on neuroblastoma cell lines. Since neuroblastomas commonly relapse in bone marrow, a hypoxic tissue compartment, and many chemotherapeutic agents are antagonized by hypoxia, our purpose was to study in these cell lines several factors influencing 4-HPR-induced cytotoxicity, including induced levels of ROS, effects of physiologic hypoxia and antioxidants, levels of ceramide, and the mechanism of cell death. METHODS: ROS generation was measured by carboxydichlorofluorescein diacetate fluoresence. Ceramide was quantified by radiolabeling and thin-layer chromatography. Immunoblotting was used to assess p53 protein levels. Apoptosis (programmed cell death) and necrosis were analyzed by nuclear morphology and internucleosomal DNA fragmentation patterns. Cytotoxicity was measured by a fluorescence-based assay employing digital imaging microscopy in the presence or absence of the pancaspase enzyme inhibitor BOC-d-fmk. Statistical tests were two-sided. RESULTS/CONCLUSIONS: In addition to increasing ROS, 4-HPR (2.5-10 microM) statistically significantly increased the level of intracellular ceramide (up to approximately 10-fold; P<.001) in a dose-dependent manner in two neuroblastoma cell lines, one of which is highly resistant to alkylating agents and to etoposide. Cell death induced by 4-HPR was reduced but not abrogated by hypoxia in the presence or absence of an antioxidant, N-acetyl-L-cysteine. Expression of p53 protein was not affected by 4-HPR. Furthermore, the pan-caspase enzyme inhibitor BOC-d-fmk prevented apoptosis, but not necrosis, and only partially decreased cytotoxicity induced by 4-HPR, indicating that 4-HPR induced both apoptosis and necrosis in neuroblastoma cells. IMPLICATIONS: 4-HPR may form the basis for a novel, p53-independent chemotherapy that operates through increased intracellular levels of ceramide and that retains cytotoxicity under reduced oxygen conditions.

Acetylcysteine↗
PubMed1999

The plasminogen-plasminogen activator (PA) system in neuroblastoma: role of PA inhibitor-1 in metastasis.

Proteases of the plasminogen-plasminogen activator (PA) system play an important role in cancer metastasis. We have examined the expression of these proteases and their cell surface receptors and inhibitors in neuroblastoma, a tumor that originates in cells of the neural crest and is the second most common solid tumor in children. This analysis was performed in seven established human cell lines and 20 primary tumor specimens. Urokinase PA and, in particular, tissue-type PA were expressed in cell lines and in tumor tissues; however, their levels of expression did not correlate with clinical stage. There was little evidence suggesting that neuroblastoma cells concentrate PA activity at their cell surface because urokinase-type PA receptor mRNA was detected in two cell lines and in 5 of 20 tumor samples by reverse transcription-PCR only. PA inhibitor (PAI)-2 was absent in all cell lines and tumor tissue samples examined. However, PAI-1, which was not expressed by the cell lines, was expressed by stromal cells and, specifically, endothelial cells in tumor tissue. By extending the analysis of PAI-1 expression in 64 primary tumor specimens, we found that high PAI-1 expression paradoxically correlated with metastatic stage and tumor recurrence. In vitro experiments indicated that the expression of PAI-1 by human microvascular endothelial cells was stimulated in the presence of SK-N-BE(2) human neuroblastoma cells and neuroblastoma culture medium. Recombinant PAI-1 also promoted SK-N-BE(2) cell detachment from vitronectin and migration from vitronectin toward fibronectin. From these data, we conclude that the up-regulation of PAI-1 expression in endothelial cells may promote rather than inhibit metastasis in neuroblastoma.

Cell Adhesion↗
PubMed1998

Drug resistance patterns of human neuroblastoma cell lines derived from patients at different phases of therapy.

To determine whether neuroblastomas acquire a sustained drug-resistant phenotype from exposure to chemotherapeutic agents given to patients in vivo, we studied neuroblastoma cell lines established at different points of therapy: six at diagnosis before therapy (DX), six at progressive disease during induction therapy (PD-Ind), and five at relapse after intensive chemoradiotherapy and bone marrow transplantation (PD-BMT). Cells were maintained in the absence of drug selective pressure. Dose-response curves of melphalan, cisplatin, carboplatin, doxorubicin, and etoposide for the cell line panel were determined by measuring cytotoxicity with a 96-well-plate digital imaging microscopy (DIMSCAN) microassay. Drug resistance of cell lines progressively increased with the intensity of therapy delivered in vivo. The greatest resistance was seen in PD-BMT cell lines: IC90 values in PD-BMT cell lines were higher than clinically achievable drug levels by 1-37 times for melphalan, 1-9 times for carboplatin, 25-78 times for cisplatin, 6-719 times for doxorubicin, and 3-52 times for etoposide. Genomic amplification of MYCN did not correlate with resistance. Cross-resistance by Pearson correlation (r > or = 0.6) was observed between: (a) cisplatin + doxorubicin; (b) carboplatin + cisplatin, etoposide, or melphalan; (c) etoposide + cisplatin, melphalan, or doxorubicin. These data indicate that during therapy, neuroblastomas can acquire resistance to cytotoxic drugs because of the population expansion of tumor cells possessing stable genetic or epigenetic alterations that confer resistance.

Antineoplastic Agents↗
PubMed1998

Matrix metalloproteinases-2 and -9 are expressed in human neuroblastoma: contribution of stromal cells to their production and correlation with metastasis.

Neuroblastoma, the second most common solid childhood tumor, can be a highly invasive and metastatic form of cancer. To assess the role of matrix-degrading proteases in this cancer, we have examined the expression of matrix metalloproteinases (MMPs) and their corresponding tissue inhibitors of metalloproteinases (TIMPs) in 7 human neuroblastoma cell lines and 24 primary untreated tumors. MMP-2 (gelatinase A) and MMP-9 (gelatinase B) were the only two MMPs expressed. MMP-2 was detected predominantly in an inactive proform in all tumor cell lines and tumor tissue extracts. The lack of MMP-2 activation in cell lines was attributed to the absence of expression of a membrane-type MMP (MT1-MMP), which activates proMMP-2, and to the abundant expression of TIMPs, particularly TIMP-2. Immunohistochemical analysis of tumor tissue samples indicated that MMP-2 was present in both tumor cells and stromal cells. In contrast, MMP-9 was not expressed by neuroblastoma cell lines but was present in inactive and active forms in extracts from tumor tissues. Immunohistochemical analysis of positive specimens indicated that MMP-9 was predominantly present in stromal, vascular, and perivascular cells surrounding nests of tumor cells. There was no correlation between the levels of these MMPs and the MYCN copy number or the histopathological phenotype. However, there were higher levels of MMP-2 and MMP-9 in stage IV (metastatic) disease when compared with stages I and II (noninvasive and nonmetastatic) or IV-S (P < 0.05).

Collagenases↗
PubMed1998

Engraftment after myeloablative doses of 131I-metaiodobenzylguanidine followed by autologous bone marrow transplantation for treatment of refractory neuroblastoma.

BACKGROUND: Metaiodobenzylguanidine (MIBG) labeled with 131I has been used for targeted radiotherapy of neural crest tumors, with bone marrow suppression being the primary dose-limiting toxicity. The purpose of this study was to examine the engraftment and toxicity of higher myeloablative doses of 131I-MIBG with autologous bone marrow support. PROCEDURE: Twelve patients with refractory neuroblastoma were given infusions of their autologous, cryopreserved bone marrow following 1-4 doses of 131I-MIBG. The median cumulative administered activity per kilogram of 131I-MIBG was 18.0 mCi/kg (range 14.1-50.2 mCi/kg), the median total activity was 594 mCi (range 195-1,353 mCi), and the median cumulative whole body irradiation from 131I-MIBG was 426 cGy (range 256-800 cGy). A median of 2.5 x 10(8) viable cells/kg (range 0.9-4.7 x 10(8) cells/kg) was given in the bone marrow infusion. RESULTS: All 12 patients achieved an absolute neutrophil count > 500/microliter with a median of 19 days, but only 5/11 evaluable patients achieved red cell transfusion independence, in a median of 44 days; and 4/11 evaluable patients achieved platelet count > 20,000/microliter without transfusion, in a median of 27 days. CONCLUSIONS: Autologous bone marrow transplantation may allow complete hematopoietic reconstitution following ablative 131I-MIBG radiotherapy in patients with neuroblastoma. Risk factors for lack of red cell or platelet recovery include extensive prior chemotherapy, progressive disease at the time of transplant, especially in the bone marrow, and a history of prior myeloablative therapy with stem cell support.

3-Iodobenzylguanidine↗
PubMed1998

Phase I dose escalation of 131I-metaiodobenzylguanidine with autologous bone marrow support in refractory neuroblastoma.

PURPOSE: The analogue 131I-metaiodobenzylguanidine (MIBG), which is specifically targeted to neuroblastoma cells, may provide more effective and less toxic treatment for neuroblastoma than conventional external-beam radiotherapy. We report a dose escalation study of 131I-MIBG to define dose-limiting toxicity without and with autologous bone marrow support. PATIENTS AND METHODS: Thirty patients with relapsed neuroblastoma were treated in groups of six with escalating doses of 3 to 18 mCi/kg of 131I-MIBG. After rapid escalation in the first three patients treated at 3 to 6 mCi/kg, treatment was escalated in 3-mCi/kg increments from 9 to 18 mCi/kg. Autologous tumor-free bone marrow was cryopreserved in all patients receiving 12 mCi/kg and more. Toxicity and response were assessed. RESULTS: Eighty percent of patients who received 12 mC/kg or more experienced grade 4 thrombocytopenia and/or neutropenia. Dose-limiting hematologic toxicity was reached at 15 mCi/kg, at which level two of five assessable patients required bone marrow reinfusion for absolute neutrophil count (ANC) of less than 200/microL for more than 2 weeks, and four of nine at the 18-mCi/kg level. Prolonged thrombocytopenia was common, with failure to become platelet-transfusion independent in nine patients. One patient with extensive prior treatment developed secondary leukemia and three became hypothyroid. Responses were seen in 37% of patients, with one complete response (CR), 10 partial response (PR), three mixed response, 10 stable disease, and six progressive disease. The minimum dose of 131I-MIBG for 10 of the 11 responders was 12 mCi/kg. CONCLUSION: Treatment with 131I-MIBG has mainly hematologic toxicity, which can be abrogated with bone marrow rescue. The high response rate in refractory disease suggests that this agent may be useful in combination with myeloablative chemotherapy and autologous stem-cell rescue to improve outcome in advanced neuroblastoma.

3-Iodobenzylguanidine↗