NF-kappa B activation mediates doxorubicin-induced cell death in N-type neuroblastoma cells.

Neuroblastoma is the most common extracranial solid tumor of childhood. N-type neuroblastoma cells (represented by SH-SY5Y and IMR32 cell lines) are characterized by a neuronal phenotype. N-type cell lines are generally N-myc amplified, express the anti-apoptotic protein Bcl-2, and do not express caspase-8. The present study was designed to determine the mechanism by which N-type cells die in response to specific cytotoxic agents (such as cisplatin and doxorubicin) commonly used to treat this disease. We found that N-type cells were equally sensitive to cisplatin and doxorubicin. Yet death induced by cisplatin was inhibited by the nonselective caspase inhibitor z-Val-Ala-Asp-fluoromethylketone or the specific caspase-9 inhibitor N-acetyl-Leu-Glu-His-Asp-aldehyde, whereas in contrast, caspase inhibition did not prevent doxorubicin-induced death. Neither the reactive oxygen species nor the mitochondrial permeability transition appears to play an important role in this process. Doxorubicin induced NF-kappa B transcriptional activation in association with I-kappa B alpha degradation prior to loss of cell viability. Surprisingly, the antioxidant and NF-kappa B inhibitor pyrrolidine dithiocarbamate blocked doxorubicin-induced NF-kappa B transcriptional activation and provided profound protection against doxorubicin killing. Moreover, SH-SY5Y cells expressing a super-repressor form of I-kappa B were completely resistant to doxorubicin killing. Together these findings show that NF-kappa B activation mediates doxorubicin-induced cell death without evidence of caspase function and suggest that cisplatin and doxorubicin engage different death pathways to kill neuroblastoma cells.

Bcl-2 and M-Myc coexpression increases IGF-IR and features of malignant growth in neuroblastoma cell lines.

The bcl-2 and c-myc oncogenes cooperate to transform multiple cell types. In the pediatric malignancy NB(2), Bcl-2 is highly expressed. In tumors with a poor prognosis, N-Myc, a protein homologous to c-Myc, is overexpressed as a result of gene amplification. The present study was designed to determine whether Bcl-2 cooperates with N-Myc to bestow a tumorigenic phenotype to neuroblastoma (NB) cells. NB cell lines that at baseline express neither Bcl-2 nor N-Myc were stably transfected to express these gene products. In this model, we found Bcl-2 rescues N-Myc-expressing cells from apoptosis induced by serum withdrawal. Coexpression of Bcl-2 and N-Myc supports growth in low serum conditions and anchorage-independent growth in soft agar. Similarly, in vivo tumorigenic and angiogenic activity was dependent on coexpression. Our data further suggests that the mechanism underlying these changes involves the receptor for insulin growth factor type I (IGF-IR).

Successful bone marrow transplantation in a patient with Schimke immuno-osseous dysplasia.

Early death in Schimke immuno-osseous dysplasia often results from renal failure and/or cell-mediated immunodeficiency. Kidney transplants have improved renal function, but effective therapy for the immunodeficiency has not yet been reported. We describe markedly improved marrow function 2 years after bone marrow transplantation in a boy with Schimke immunoosseous dysplasia.

Fatal lymphoproliferative disease as a complication of Evans syndrome.

A 9-month-old boy had bruising and petechiae. Investigation revealed a Coombs-positive hemolytic anemia and immune-mediated thrombocytopenia. The infant was treated with intravenous immunoglobulin and steroids. The infant eventually had recurrent fevers, hepatosplenomegaly, pulmonary nodules, and parenchymal central nervous system (CNS) lesions develop. Results of a lung biopsy revealed a polyclonal lymphoproliferative disease. Polymerase chain reaction analysis showed the presence of the Epstein-Barr (EB) viral genome in the lung nodules. The infant died from progressive lung disease 6 months after the initial symptoms of Evans syndrome. Lymphoproliferative disease is known to occur in a variety of settings after immunosuppression, especially in solid organ transplant recipients. We report a case of polyclonal lymphocyte proliferation in a patient with Evans syndrome.

IGF-I receptor activation and BCL-2 overexpression prevent early apoptotic events in human neuroblastoma.

The type I insulin-like growth factor receptor (IGF-IR) is important for mitogenesis, transformation, and survival of tumor cells. The current study examines the effect of IGF-IR expression and activation on apoptosis in SHEP human neuroblastoma cells. SHEP cells undergo apoptosis which is prevented by IGF-I addition or overexpression of the IGF-IR (SHEP/IGF-IR cells). High mannitol treatment activates caspase-3 by 1 h in SHEP cells while caspase-3 activation is delayed by 3 h in SHEP/IGF-IR cells. Transfection with Bcl-2 (SHEP/Bcl-2 cells) prevents serum withdrawal and mannitol induced apoptosis and caspase-3 activation. Mannitol induces mitochondrial membrane depolarization in both SHEP and SHEP/IGF-IR cells. IGF-IR activation or overexpression of Bcl-2 in SHEP cells prevents mitochondrial membrane depolarization. Collectively, these results suggest that IGF-IR or Bcl-2 overexpression in neuroblastoma cells promotes cell survival by preventing mitochondrial membrane depolarization and caspase-3 activation, ultimately leading to increased tumor growth.

Thrombospondin-1 induces endothelial cell apoptosis and inhibits angiogenesis by activating the caspase death pathway.

Thrombospondin-1 (TSP1) is a potent natural inhibitor of angiogenesis. Although TSP1 has been reported to induce endothelial cell apoptosis in vitro and to downregulate neovascularization in vivo, the molecular mechanisms that link these two processes have yet to be established. Here we report that TSP1 mediates endothelial cell apoptosis and inhibits angiogenesis in association with increased expression of Bax, decreased expression of Bcl-2, and processing of caspase-3 into smaller proapoptotic forms. The ability of TSP1 to induce both endothelial cell apoptosis in vitro and to suppress angiogenesis in vivo was blocked by the caspase-3 inhibitor z-DEVD-FMK. TSP1 also attenuated VEGF-mediated Bcl-2 expression in endothelial cells in vitro and angiogenesis in vivo. Furthermore, TSP1 induced endothelial cell apoptosis and inhibited neovascularization in sponge implants in SCID mice. We conclude that TSP1 induces endothelial cell apoptosis and inhibits neovascularization by altering the profile of survival gene expression and activating caspase-3.

The response to splenectomy in pediatric patients with idiopathic thrombocytopenic purpura who fail high-dose intravenous immune globulin.

BACKGROUND: A recent article by Law et al concluded that patients with idiopathic thrombocytopenic purpura (ITP) who have a poor response to intravenous immune globulin (IgG) are unlikely to have a good or excellent response to surgical splenectomy. METHODS: The authors studied retrospectively 23 pediatric patients age 11.7 +/- 1.0 years with ITP who had been treated with IgG before undergoing splenectomy. As in the aforementioned article, the responses to the 2 treatments were classified on the basis of the platelet count as poor (<50,000/mm3), good (50,000 to 150,000/mm3), or excellent (>150,000/mm3). For patients who received multiple IgG treatments, both initial and final treatment responses were analyzed. RESULTS: Sixteen patients had an excellent or good initial response to IgG. Of these 16 patients, 14 had an excellent or good response to splenectomy. Among the 7 patients who had a poor response to IgG there were 3 who had an excellent or good response to splenectomy (43%), and 4 patients who had a poor response to splenectomy. A good or excellent response to initial treatment with IgG was associated with a significant probability of a good or excellent response to splenectomy (P = .045). CONCLUSIONS: A good or excellent response to IgG may be predictive of a favorable response to splenectomy. However, a poor response to IgG does not preclude a satisfactory response to splenectomy in pediatric patients with ITP.

Overexpression of Akt/AKT can modulate chemotherapy-induced apoptosis.

The AKT oncogenes are amplified or AKT kinase activity is constitutively elevated in several types of human malignancy. We sought to determine whether AKT might play a role in the development of resistance to apoptosis induced by chemotherapy. We showed that ovarian cancer cells either overexpressing constitutively active Akt/AKT1 or containing AKT2 gene amplification were highly resistant to paclitaxel than cancer cells express low AKT levels. The Akt/AKT1 clones also contained higher levels of phospho-Bad protein than parental cells. Further, the complexes between the endogenous proapoptotic protein, Bad, and the anti-apoptotic protein, BC1-XL were undetectable in Akt/AKT1 clones. These results suggest that Akt/AKT1 expressed in these clones can phosphorylate Bad and prevent it from binding to Bcl-XL. Furthermore, overexpression of Akt/AKT1 can inhibit the release of cytochrome c induced by paclitaxel. Therefore, our findings provide evidence that aberrant expression or activation of AKT in cancer cells may confer resistance to paclitaxel.

Role of p53 in the regulation of irradiation-induced apoptosis in neuroblastoma cells.

Wild-type p53 plays a crucial role in the control of apoptosis following ionizing radiation (IR); conversely, mutant p53 is associated with IR resistance. Although wild-type p53 is expressed in virtually all neuroblastoma tumors, treatment failures secondary to inadequate local control with radiotherapy are a problem in patients with advanced stage disease. This apparent paradox is the focus of our interest. The Shep-1 neuroblastoma cell line is highly resistant to IR. This cell line contains a wild-type p53 gene and is an ideal model for studying the mechanism of IR resistance in this disease. Following high-dose IR, cell fractionation demonstrated that p53 is induced and targeted to the nucleus. The induced p53 is functional as p53-responsive genes (Waf-1 and MDM-2) are appropriately induced following IR. Intriguingly, overexpression of p53 could reverse the inherent IR resistance of Shep-1 cells. Multiple cell lines expressing variable levels of exogenous temperature-sensitive p53 were generated. Pulse induction of p53 alone did not affect Shep-1 cell viability, while induction of p53, followed by IR, resulted in cell death and DNA fragmentation proportional to the dose of IR and the level of p53 expression. These findings demonstrate that p53 overexpression renders Shep-1 cells IR-sensitive and suggest that large quantities of exogenous p53 can overcome the factors inhibiting p53-mediated, IR-induced apoptosis.

Successful treatment of neonatal arterial thromboses with recombinant tissue plasminogen activator.

Seven newborns were treated with recombinant tissue plasminogen activator for arterial thromboses. Complete lysis occurred in four of seven and partial in two of seven patients. Serious bleeding complications were observed in two of seven patients. This and published experience suggest that successful lysis with recombinant tissue plasminogen activator occurs in most patients and that hemorrhagic complications are unusual but are not.

Keratinocytes derived from psoriatic plaques are resistant to apoptosis compared with normal skin.

Previously we observed that hyperplastic epidermal keratinocytes characteristic of psoriasis had abundant amounts of the cell survival protein Bcl-xL; however, whether this overexpression correlated with enhanced survival was unclear because the majority of epidermal cells possess nuclei that are positively labeled by an assay typically regarded as indicative of cells undergoing apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining). To clarify this apparent discrepancy, we explored the propensity of keratinocytes derived from psoriatic plaques to undergo apoptosis and also determined the reliability of TUNEL staining as an indicator of apoptosis in keratinocytes in vitro and in vivo. First, a keratinocyte cell line, HaCat, was examined before and after being suspended in semisolid medium (methylcellulose) using flow cytometry to detect TUNEL-positive cells, and the percentage of positive cells was correlated to the presence or absence of double-stranded DNA fragmentation using pulsed field gel electrophoresis. After 18 hours in methylcellulose suspension, apoptosis was detected in HaCat cells when at least 5% of the cell population was undergoing programmed cell death. Second, we examined 23 clinical specimens of skin (13 from psoriatic patients and 10 from healthy control subjects) and observed that no double-stranded DNA fragmentation was present in any of the freshly isolated keratinocytes from either normal or psoriatic patients. Keratinocytes from 9 of 12 normal skin samples underwent double-stranded DNA fragmentation after being in methylcellulose for 18 to 24 hours, which contrasts with keratinocytes from lesions of psoriasis where only 1 of 13 of the skin samples had these changes. Third, two-color immunofluorescence staining of psoriatic plaques revealed that numerous TUNEL-positive keratinocytes were also positive for proliferating cell nuclear antigen and Ki-67 antigens and that by flow cytometry TUNEL-positive keratinocytes obtained from psoriatic plaques possessed a DNA content profile indicative of proliferating and not dying cells. These results demonstrate that keratinocytes within psoriatic plaques do not have double-stranded DNA breaks, that they have a prolonged capacity to resist induction of apoptosis compared with normal-skin-derived keratinocytes or cultured HaCat cells, and that caution is necessary for proper interpretation related to detection of 3'-OH DNA ends (ie, TUNEL positivity) in skin, as it can be associated with DNA synthesis as well as cell death.

Thrombospondin-1 suppresses tumorigenesis and angiogenesis in serum- and anchorage-independent NIH 3T3 cells.

Thrombospondin-1 (TSP1) is a multifunctional matrix protein that influences the growth and function of a variety of normal and neoplastic epithelial and mesenchymal cell types. In vivo, TSP1 has shown potent antitumor activity in suppressing tumor neovascularization. Paradoxically, however, as we have reported, NIH 3T3 fibroblasts overexpressing TSP1 acquire the transformation-associated phenotypes of serum and anchorage independence in vitro but fail to form tumors in nude mice. To investigate these divergent results, and to determine the functional domains in TSP1 that confer serum and anchorage independence as well as antitumor and antiangiogenic activities, we transfected a series of deletion constructs of TSP1 into NIH 3T3 cells and into a v-src-transformed NIH 3T3 line. The antiangiogenic activity of TSP1-expressing, v-src-transformed NIH 3T3 cells was examined by assaying the conditioned media for inhibition of endothelial cell chemotaxis and suppression of basic fibroblast growth factor-mediated angiogenesis in the rat cornea. The link between TSP1 antitumor and antiangiogenic activities was assessed by measuring the rate of tumor growth and counting factor VIII-stained microvessels in the solid tumors developing in nude mice. Our results indicate that v-src NIH 3T3 cells transfected with a 449-amino acid N-terminal domain of TSP1 exhibit a dose-dependent suppression of tumor growth and neovascularization in nude mice. Truncated forms of TSP1 containing the type 1 properdin domain suppressed both endothelial cell chemotaxis and comeal neovascularization. Furthermore, when full-length TSP1 and deletion constructs containing the antiangiogenic type I properdin domain were transfected into highly tumorigenic v-src-transformed NIH 3T3 cells, they were able to confer transdominant suppression of tumorigenicity and angiogenesis of these cells in nude mice. These results confirm the role of TSP1 as a potent inhibitor of angiogenesis and provide support for the notion that alterations in the net balance between inducers and inhibitors of angiogenesis are largely responsible for the sustained growth of solid tumors in vivo.

Successful treatment of infantile hemangiomas with interferon-alpha-2b.

PURPOSE: Hemangiomas are benign tumors occurring in 10% of infants. A small percentage are complicated by blockage of vital structures, consumptive coagulopathy, or heart failure, resulting in a mortality of -20% of patients with complications. Here, we describe four infants with complicated hemangiomas responding to interferon-alpha-2b therapy. PATIENTS AND METHODS: Four children with hemangiomas were treated with interferon-alpha-2b for complicating heart failure (1), visual impairment (2), or coagulopathy (1). Patients received interferon-alpha-2b alone or in conjunction with corticosteroid therapy over 2 to 9 months. Imaging studies and urinary basic fibroblast growth factor (bFGF) levels were used to monitor treatment response. RESULTS: Three of four patients demonstrated involution of the hemangiomas with improvement in their coagulopathy or visual impairment. The fourth patient expired due to cardiac complications despite radiologic evidence of hemangioma involution. Side effects associated with interferon-alpha-2b treatment included elevated transaminases (2) and leukocytosis (2), which resolved upon completion of therapy. One patient developed mild gross motor delay (1), which improved after cessation of therapy. Decreased urinary bFGF levels correlated with hemangioma involution. CONCLUSION: Interferon-alpha-2b therapy is an effective, well-tolerated treatment for complicated hemangiomas. Measurement of urinary bFGF levels may provide an objective method for monitoring treatment response.

Reversal of protein-losing enteropathy with heparin therapy in three patients with univentricular hearts and Fontan palliation.

We studied three pediatric patients with protein-losing enteropathy in conjunction with univentricular hearts and right atrial to pulmonary artery anastomosis (Fontan operation) before and during heparin therapy. Each patient showed dramatic improvements in symptoms, marked elevations in serum albumin levels, and quantitative reversal of enteric protein loss within a few weeks of beginning therapy. These findings suggest that heparin may be an important treatment for this poorly understood condition.

Bcl-xS enhances adenoviral vector-induced apoptosis in neuroblastoma cells.

bcl-x is a member of the bcl-2 family of genes and by alternative splicing gives rise to two distinct mRNAs: bcl-xL and bcl-xS. We have previously investigated the expression of Bcl-x in neuroblastoma (NB) cell lines and have shown that Bcl-xL is expressed and functions to inhibit chemotherapy-induced apoptosis. However, none of the NB cell lines expressed Bcl-xS. The aim of the present study was to determine the effects of Bcl-xS expression on the viability of NB cells. A panel of NB cell lines (CHP-382, GOTO, SHEP-1, SHSY-5Y, and GI-CA-N) were infected with either a bcl-xS adenovirus (pAdRSV-bcl-xS) or a control virus (pAdRSV-lac-z). NB cells showed loss of viability with both viruses, although the bcl-xS virus was most toxic. Importantly, infection with the bcl-xS adenovirus resulted in rapid loss of cell viability, DNA fragmentation, and morphological features of apoptosis even in NB cells transfected to overexpress Bcl-2 and Bcl-xL. These findings suggest that deregulated expression of Bcl-xS using an adenovirus may provide a novel mechanism for initiating cell death in tumors that express Bcl-2 or Bcl-xL.

Neuroblastoma: positron emission tomography with 2-[fluorine-18]-fluoro-2-deoxy-D-glucose compared with metaiodobenzylguanidine scintigraphy.

PURPOSE: To assess the uptake in neuroblastoma of 2-[fluorine-18] -fluoro-2-deoxy-D-glucose (FDG) versus metaiodobenzylguanidine (MIBG). MATERIALS AND METHODS: Seventeen patients with known or suspected neuroblastoma underwent FDG positron emission tomography (PET) (20 scans) and MIBG scintigraphy. Tumor uptake of FDG was quantified on positive PET scans. RESULTS: Tumor uptake of FDG was detected in 16 of 17 patients (18 of 20 scans). Neuroblastomas and their metastases avidly concentrated FDG prior to chemotherapy or radiation therapy. Uptake after therapy was variable. Uptake of FDG was intense in one patient with neuroblastoma that failed to accumulate MIBG. In 13 of the 20 scans, however, MIBG was rated superior to FDG for delineation of tumor compared with background and normal organs. CONCLUSION: Most neuroblastomas accumulate FDG. The mechanism of MIBG uptake is more intense prior to therapy. Concentration of FDG is not dependent on type 1 catecholamine uptake. FDG PET helps define the distribution of neuroblastomas that fail to concentrate MIBG.

Neonatal purpura fulminans in association with factor V R506Q mutation.

We report a case of neonatal purpura fulminans associated with activated protein C resistance. Analysis of DNA demonstrated heterozygosity for the factor V R506Q mutation. The neonate, at 8 hours of age, had progressive purpuric skin lesions and later had evidence of microvascular, hemorrhagic thrombosis in the brain. The baby was treated with fresh frozen plasma infusions and had complete resolution of the skin lesions and no apparent long-term complications. We suggest that activated protein C resistance testing be included in the initial evaluation of neonatal purpura fulminans.

PET hydroxyephedrine imaging of neuroblastoma.

UNLABELLED: The goals of this investigation were to characterize the uptake of 11C-hydroxyephedrine (HED) in neuroblastoma and to determine the feasibility and potential advantages of utilizing this compound as a tumor imaging agent. METHODS: Seven patients with known or subsequently proven neuroblastoma were studied. Each patient underwent PET scanning with 11C-HED. Six of seven patients underwent scintigraphy with [123I]meta-iodobenzylguanidine (MIBG), and two patients were also studied with [18F]FDG PET. For six patients, CT or MR images were available for comparison. RESULTS: Neuroblastomas were located by PET scanning with 11C-HED in all seven patients. The uptake of HED into neuroblastomas was rapid; tumors were evident on images within 5 min postintravenous injection. Those lesions in the field of view of the PET camera were also identified on [123I]MIBG scintigraphic images. In two patients, tumor deposits in the abdomen were better visualized with MIBG scintigraphy due to relatively less hepatic accumulation of MIBG than HED. CONCLUSION: PET scanning with HED for neuroblastoma results in high quality functional images of the tumors that can be obtained within minutes following injection.

Insulin-like growth factor II in the pathogenesis of human neuroblastoma.

Insulin-like growth factor II (IGF-II) acts as an autocrine growth factor for many in vitro tumor cell lines including neuroblastoma. To examine the role of IGF-II in tumor biology we have analyzed a total of 56 primary neuroblastoma tumor samples for the presence of IGF-II using a combination of mRNA and protein analysis. A group of 21 samples was examined for the presence of IGF-II mRNA by slot blot and a separate group of 37 samples was examined for IGF-II immunoreactivity. IGF-II was detected in 48% of the total tumor specimens analyzed. IGF-II immunoreactivity was observed in cells resembling developing neuroblasts and was confined to the cytoplasm and proximal neurites. The appearance of IGF-II mRNA and protein did not correlate with tumor prognostic features including stage, histology, or N-myc amplification. These data suggest that the expression of IGF-II is not confined to a specific stage of the disease but may have a broader role in the pathogenesis of neuroblastoma.

Congenital mesoblastic nephroma metastatic to the brain: a report of two cases.

Congenital mesoblastic nephroma was originally believed to be a universally benign neoplasm. More recently, aggressive congenital mesoblastic nephromas have been described with local recurrence and/or metastases. We report two patients with documented congenital mesoblastic nephroma which later metastasized to the brain.