Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bloom's syndrome (BS) is an autosomal recessive disease characterized by short stature, sensitivity to sunlight, and telangiectasic malar erythema. It is associated to chromosomal breakage, to primary combined immunodeficiency, and to a high incidence of neoplasias. The authors report the case of two siblings with BS and associated immunodeficiency. Both patients were male and 5 (A) and 4 (B) years old at the time of diagnosis. Chronic diarrhea, recurrent otitis media, purulent rhinitis, conjunctivitis and pyodermatitis were reported by patient A. Patient B was admitted with diagnosis of bilateral neuroblastoma and had the tumor resected. Later on, he presented with oral moniliasis, herpetic stomatitis, and skin abscesses. This patient did not have recurrent infections. Immunological evaluation showed normal serum levels of CH50, C3, and C4 for both patients. Serum IgG, IgA, IgM, and salivary IgA levels were: 455 mg/dl, 15mg/dl, 20mg/dl, 0.6mg/dl for A, and 400mg/dl, 15mg/dl, 20mg/dl, and 0.2mg/dl for B, respectively. Serum antipolio antibodies (1, 2, and 3) were normal, and low levels of isohemagglutinins were observed in both patients. T cells subset determination showed: patient A--OKT3 = 66%, OKT4 = 33%, OKT8 = 32%, and 4/8 ratio = 1.0; patient B--OKT3 = 70%, OKT4 = 32%, OKT8 = 34%, and 4/8 ratio = 1.0. In vitro cellular immune response to PHA was depressed only in patient B. Patients karyotype showed chromosomal breaks with sister chromatid exchanges. Neither patient had abnormal alphafetoprotein and carcinoembryonic antigen serum levels. The rarity of such associations justifies the presentation of the cases.
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PMID:[Familial Bloom's syndrome associated with neuroblastoma]. 221 4

Chromosomes with regions rich in mitotic chiasmata in Bloom syndrome (1,3,6,11,12,17,19, and 22) have been compared for various parameters to similar-sized chromosomes 2, 4, 7, 10, 9, 18, 20, and 21 with the following results: (1) The number of genes localized on the test chromosomes is significantly higher (248) than that in the control chromosomes (133). (2) The number of trisomic abortions is significantly lower (45) for the test chromosomes than for the control chromosomes (140). (3) Homogeneously stained regions in neuroblastoma lie at chiasma-containing regions on chromosome arms 1p, 6p, 17q, and 19p or q. (4) The average chiasma density of regions with at least one oncogene is 2.414, whereas that of regions containing no known oncogene is 1.137; however, the difference is not statistically significant. The association of constant cancer chromosome breaks is also in the positive direction, but is not statistically significant. Our tentative conclusion is that the chiasma-rich regions which are Q-dark and early-replicating, and therefore assumed to contain active "housekeeping" genes are extended in interphase. Thus they are available for mitotic crossing-over. In the trisomic state they act as trisomy lethals, leading to early abortions. Being gene-rich they are more likely to contain oncogenes which is reflected also in their agreement with cancer breakpoints. The very high incidence of cancer in Bloom syndrome is a further indication of the possible association of cancer-related phenomena and mitotic crossing-over.
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PMID:Mitotic chiasmata, gene density, and oncogenes. 399 47

Neuroblastoma, common in children, rarely develops in adults. We recently treated a patient with adult neuroblastoma. A 34-year-old man complained of a swelling in right inguinal region. CT scan showed swelling of retroperitoneal and inguinal lymph nodes, and bone scintigram by 99mTc-HMDP showed an abnormal uptake in the swollen lymph nodes. Chemotherapy with CDDP (cisplatinum), VP-16 (etoposide), BLM (bleomycin), ADM (adriamycin) was not effective. Histopathological examination of a biopsy specimen revealed neuroblastoma. Another chemotherapy with CPM (cyclophosphamide), VCR (vincristine), ADM, DTIC (dacarbazine), CDDP, VP-16 was effective in decreasing the tumor size. Further high dose chemotherapy with CPM, ADM, CDDP, VP-16 combined with peripheral blood stem cell transplantation led to almost complete disappearance of the tumor and normalization of blood tumor markers (neuron specific enolase and immunosuppressive acidic protein). Retroperitoneal lymph node dissection demonstrated well-differentiated neuroblastoma in the excised tissue. Six months postoperatively, the tumor recurred in the pelvic cavity. Although chemotherapy and radiotherapy were given, he died of the disease 12 months postoperatively.
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PMID:[A case of adult neuroblastoma arising in the retroperitoneal space]. 1159 7

Telomeres are nucleoprotein complexes located at the end of eukaryotic chromosomes. They have essential roles in preventing terminal fusions, protecting chromosome ends from degradation, and in chromosome positioning in the nucleus. These terminal structures consist of a tandemly repeated DNA sequence (TTAGGG in vertebrates) that varies in length from 5 to 15 kb in humans. Several proteins are attached to this telomeric DNA, some of which are also involved in different DNA damage response pathways, including Ku80, Mre11, NBS and BLM, among others. Mutations in the genes encoding these proteins cause a number of rare genetic syndromes characterized by chromosome and/or genetic instability and cancer predisposition. Deletions or mutations in any of these genes may also cause a telomere defect resulting in accelerated telomere shortening, lack of end-capping function, and/or end-to-end chromosome fusions. This telomere phenotype is also known to promote chromosomal instability and carcinogenesis. Therefore, it is essential to understand the interplay between telomere biology and genome stability. This review is focused in the dual role of chromosome fragility proteins in telomere maintenance.
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PMID:Telomere dysfunction in genome instability syndromes. 1534 4

Poly ADP-ribose polymerase inhibitors have been shown to target cells with homologous recombination DNA repair defects. We report that poly ADP-ribose polymerase inhibitors induces apoptosis in cells deficient in other key DNA repair components. Chromosomal instability disorders, Fanconi Anemia and Bloom's syndrome have dysfunctional DNA repair and an increased likelihood of leukemic transformation. PI addition to Fanconi Anemia and Bloom's syndrome cells resulted in significant apoptosis. Furthermore, poly ADP-ribose polymerase inhibitors induced apoptosis in DNA repair signaling defective ATM(-/-) and NBS(-/-) fibroblasts. Immunocytochemistry showed homologous recombination was abrogated in NBS(-/-) and ATM(-/-) fibroblasts, compromised in Fanconi anemia and normal in Bloom's syndrome cells in response to poly ADP-ribose polymerase inhibitors. Strikingly, poly ADP-ribose polymerase inhibitors increases non-homologous end joining repair activity, whilst non-homologous end joining deficient cells are extremely sensitive to poly ADP-ribose polymerase inhibitors. These data suggest poly ADP-ribose polymerase inhibitors target cells with DNA repair and signaling defects rather than solely defects in homologous recombination improving the potential of poly ADP-ribose polymerase inhibitors therapy in a wider range of cancers.
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PMID:Chromosomal instability syndromes are sensitive to poly ADP-ribose polymerase inhibitors. 1883 76

Okadaic acid (OA) is a phycotoxin produced by several types of dinoflagellates causing diarrheic shellfish poisoning (DSP) in humans. Symptoms induced by DSP toxins are mainly gastrointestinal, but the intoxication does not appear to be fatal. Despite this, this toxin presents a potential threat to human health even at concentrations too low to induce acute toxicity, since previous animal studies have shown that OA has very potent tumour promoting activity. However, its concrete action mechanism has not been described yet and the results reported with regard to OA cytotoxicity and genotoxicity are often contradictory. In the present study, the genotoxic and cytotoxic effects of OA on three different types of human cells (peripheral blood leukocytes, HepG2 hepatoma cells, and SHSY5Y neuroblastoma cells) were evaluated. Cells were treated with a range of OA concentrations in the presence and absence of S9 fraction, and MTT test and Comet assay were performed in order to evaluate cytotoxicity and genotoxicity, respectively. The possible effects of OA on DNA repair were also studied by means of the DNA repair competence assay, using bleomycin as DNA damage inductor. Treatment with OA in absence of S9 fraction induced not statistically significant decrease in cell viability and significant increase in DNA damage in all cell types at the highest concentrations investigated. However, only SHSY5Y cells showed OA induced genotoxic and cytotoxic effects in presence of S9 fraction. Furthermore, we found that OA can induce modulations in DNA repair processes when exposure was performed prior to BLM treatment, in co-exposure, or during the subsequent DNA repair process.
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PMID:Assessment of okadaic acid effects on cytotoxicity, DNA damage and DNA repair in human cells. 2062 97

The MYC family of transcription factors consists of three well characterized members, c-MYC, L-MYC, and MYCN, deregulated in the majority of human cancers. In neuronal tumors such as neuroblastoma, MYCN is frequently activated by gene amplification, and reducing its expression by RNA interference has been shown to promote growth arrest and apoptosis of tumor cells. From a clinical perspective, RNA interference is not yet a viable option, and small molecule inhibitors of transcription factors are difficult to develop. We therefore planned to identify, at the global level, the genes interacting functionally with MYCN required to promote fitness of tumor cells facing oncogenic stress. To find genes whose inactivation is synthetically lethal to MYCN, we implemented a genome-wide approach in which we carried out a drop-out shRNA screen using a whole genome library that was delivered into isogenic neuroblastoma cell lines expressing or not expressing MYCN. After the screen, we selected for in-depth analysis four shRNAs targeting AHCY, BLM, PKMYT1, and CKS1B. These genes were chosen because they are directly regulated by MYC proteins, associated with poor prognosis of neuroblastoma patients, and inhibited by small molecule compounds. Mechanistically, we found that BLM and PKMYT1 are required to limit oncogenic stress and promote stabilization of the MYCN protein. Cocktails of small molecule inhibitors of CKS1B, AHCY, BLM, and PKMYT1 profoundly affected the growth of all neuroblastoma cell lines but selectively caused death of MYCN-amplified cells. Our findings suggest that drugging the MYCN network is a promising avenue for the treatment of high risk, neuroblastic cancers.
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PMID:Identification and pharmacological inactivation of the MYCN gene network as a therapeutic strategy for neuroblastic tumor cells. 2547 24

Neuroblastoma (NB) is the most common extra cranial solid tumor of childhood and often lethal in childhood. Clinical and biologic characteristics that are independently prognostic of outcome in NB are currently used for risk stratification to optimally the therapy. It includes age at diagnosis, International Neuroblastoma Staging System tumor histopathology and MYCN amplification. However, even in patients with theoretically good prognosis, such as localized tumor and non-amplified MYCN, either disease progress or recurrence may occur. Potential genetic determinants of this unfavorable behavior are not yet fully clarified. The presence of elevated expression of AHCY, PKMYT1, and BLM has accompanied poor prognosis MYCN-amplified neuroblastoma patients. Considering the potential implication of these genes on the clinical management of NB, we hypothesize that the identification of genetic variations may have significant impact during development of the recurrent or progressive disease. Using targeted DNA sequencing, we analyzed the mutation profiles of the genes PKMYT1, AHCY, and BLM in tumor samples of five patients with MYCN amplified and 15 MYCN non-amplified NB. In our study, BLM germline variants were detected in two patients with MYCN-non-amplified neuroblastoma. Our data allow us to hypothesize that, regardless of MYCN status, these mutations partially abolish BLM protein activity by impairing its ATPase and helicase activities. BLM mutations are also clinically relevant because BLM plays an important role in DNA damage repair and the maintenance of genomic integrity. We also found a novel variant in our cohort, PKMYT1 mutation localized in the C-terminal domain with effect unknown on NB. We hypothesize that this variant may affect the catalytic activity of PKMYT1 in NB, specifically when CDK1 is complexed to cyclins. The prognostic value of this mutation must be further investigated. Another mutation identified was a nonsynonymous variant in AHCY. This variant may be related to the slow progression of the disease, even in more aggressive cases. It affects the maintenance of the catalytic capacity of AHCY, leading to the consequent functional effects observed in the NB patients studied. In conclusion, our hypothesis may provide that mutations in BLM, AHCY and PKMYT1 genes found in children with MYCN-amplified or MYCN-non amplified neuroblastomas, may be associated with the prognosis of the disease.
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PMID:BLM germline and somatic PKMYT1 and AHCY mutations: Genetic variations beyond MYCN and prognosis in neuroblastoma. 2787 23