In vitro activity of a G-quadruplex-stabilizing small molecule that synergizes with Navitoclax to induce cytotoxicity in acute myeloid leukemia cells.

BACKGROUND: Acute Myeloid Leukemia (AML) is a malignancy of myeloid precursor cells that arise from genomic alterations in the expression of key growth regulatory genes causing cells to assume an undifferentiated state and continue to proliferate. Recent efforts have focused on developing therapies that target specific protein products of aberrantly expressed genes. However, many of the identified proteins are difficult to target and thought to be "undrugable" because of structural challenges, protein overexpression, or mutations that confer resistance to therapy. A novel technology that circumvents some of these issues is the use of small molecules that stabilize secondary DNA structures present in the promoters of many potential oncogenes and modulate their transcription. METHODS: This study characterizes the in vitro activity of the G-quadruplex-stabilizing small molecule GQC-05 in AML cells. The effect of GQC-05 on three AML cell lines was analyzed using viability and apoptosis assays. GQC-05 has been shown to down-regulate MYC through G-quadruplex stabilization in Burkitt's lymphoma cell lines. MYC expression was evaluated through qPCR and immunoblotting in the three AML cell lines following the treatment of GQC-05. In order to identify other therapeutic agents that potentiate the activity of GQC-05, combination drug screening was performed. The drug combinations were validated using in vitro cytotoxicity assays and compared to other commonly used chemotherapeutic agents. RESULTS: GQC-05 treatment of KG-1a, CMK and TF-1 cells decreased cell viability and resulted in increased DNA damage and apoptosis. Additionally, treatment of KG-1a, CMK and TF-1 with GQC-05 resulted in decreased expression of MYC mRNA and protein, with a more pronounced effect in KG-1a cells. Combination drug screening identified the Bcl-2/Bcl-XL inhibitor Navitoclax as a compound that potentiated GQC-05 activity. Co-treatment with GQC-05 and Navitoclax showed a synergistic decrease in cell viability of AML cells as determined by Chou-Talalay analysis, and induced more DNA damage, apoptosis, and rapid cytotoxicity. The cytotoxicity induced by GQC-05 and Navitoclax was more potent than that of Navitoclax combined with either cytarabine or doxorubicin. CONCLUSION: These results suggest that the G-quadruplex stabilizing small molecule GQC-05 induces down regulated MYC expression and DNA damage in AML cells. Treatment with both GQC-05 with a Bcl-2/Bcl-XL inhibitor Navitoclax results in increased cytotoxic activity, which is more pronounced than Navitoclax or GQC-05 alone, and more significant than Navitoclax in combination with cytarabine and doxorubicin that are currently being used clinically.

Clinical resistance associated with a novel MAP2K1 mutation in a patient with Langerhans cell histiocytosis.

Patients with Langerhans cell histiocytosis (LCH) harbor BRAF V600E and activating mutations of MAP2K1/MEK1 in 50% and 25% of cases, respectively. We evaluated a patient with treatment-refractory LCH for mutations in the RAS-RAF-MEK-ERK pathway and identified a novel mutation in the MAP2K1 gene resulting in a p.L98_K104 > Q deletion and predicted to be auto-activating. During treatment with the MEK inhibitor trametinib, the patient's disease showed significant progression. In vitro characterization of the MAP2K1 p.L98_K104 > Q deletion confirmed its effect on cellular activation of the ERK pathway and drug resistance.

The genomic landscape of the Ewing Sarcoma family of tumors reveals recurrent STAG2 mutation.

The Ewing sarcoma family of tumors (EFT) is a group of highly malignant small round blue cell tumors occurring in children and young adults. We report here the largest genomic survey to date of 101 EFT (65 tumors and 36 cell lines). Using a combination of whole genome sequencing and targeted sequencing approaches, we discover that EFT has a very low mutational burden (0.15 mutations/Mb) but frequent deleterious mutations in the cohesin complex subunit STAG2 (21.5% tumors, 44.4% cell lines), homozygous deletion of CDKN2A (13.8% and 50%) and mutations of TP53 (6.2% and 71.9%). We additionally note an increased prevalence of the BRCA2 K3326X polymorphism in EFT patient samples (7.3%) compared to population data (OR 7.1, p = 0.006). Using whole transcriptome sequencing, we find that 11% of tumors pathologically diagnosed as EFT lack a typical EWSR1 fusion oncogene and that these tumors do not have a characteristic Ewing sarcoma gene expression signature. We identify samples harboring novel fusion genes including FUS-NCATc2 and CIC-FOXO4 that may represent distinct small round blue cell tumor variants. In an independent EFT tissue microarray cohort, we show that STAG2 loss as detected by immunohistochemistry may be associated with more advanced disease (p = 0.15) and a modest decrease in overall survival (p = 0.10). These results significantly advance our understanding of the genomic and molecular underpinnings of Ewing sarcoma and provide a foundation towards further efforts to improve diagnosis, prognosis, and precision therapeutics testing.

Microarray analysis of Ewing's sarcoma family of tumours reveals characteristic gene expression signatures associated with metastasis and resistance to chemotherapy.

In Ewing's sarcoma family of tumours (ESFT), the clinically most adverse prognostic parameters are the presence of tumour metastasis at time of diagnosis and poor response to neoadjuvant chemotherapy. To identify genes differentially regulated between metastatic and localised tumours, we analysed 27 ESFT specimens using Affymetrix microarrays. Functional annotation of differentially regulated genes revealed 29 over-represented pathways including PDGF, TP53, NOTCH, and WNT1-signalling. Regression of primary tumours (n=20) induced by polychemotherapy was found to be correlated with the expression of genes involved in angiogenesis, apoptosis, ubiquitin proteasome pathway, and PI3 kinase and p53 pathways. These findings could be confirmed by in vitro cytotoxicity assays. A set of 46 marker genes correctly classifies these 20 tumours as responding versus non-responding. We conclude that expression signatures of initial tumour biopsies can help to identify ESFT patients at high risk to develop tumour metastasis or to suffer from a therapy refractory cancer.

Expression analysis of pancreatic cancer cell lines reveals association of enhanced gene transcription and genomic amplifications at the 8q22.1 and 8q24.22 loci.

Despite tremendous effort and progress in the diagnostics of pancreatic cancer with respect to imaging techniques and molecular genetics, only very few patients can be cured by surgery leading to a 5-year survival rate of only 3%. Especially the lack of chemotherapeutical options in this entity requires a better understanding of the molecular mechanisms leading to pancreatic carcinoma growth and progression in order to develop novel treatment regimens. To identify signaling pathways that are critical for this tumor entity, we compared six well-established pancreatic cancer cell lines (Capan-1, Capan-2, HUP-T3, HUP-T4, KCL-MOH, PaTu-8903) with colon cancer cell lines and tumor cell lines of non-epithelial origin by expression profiling. For this purpose we employed Human Genome Focus Arrays representing about 8500 well annotated human genes. We identified 353 genes with significantly high expression in the group of pancreatic carcinomas. Based on Gene Ontology annotations these genes are especially involved in Rho protein signal transduction, proteasome activator activity, cell motility, apoptotic program, and cell-cell adhesion processes indicating these pathways to be interesting candidates for the design of targeted therapies. Most pancreatic carcinomas are characterized by mutations in the TP53 and the KRAS genes and the absence of microsatellite instability, which could also be confirmed for our panel of pancreatic carcinoma cell lines. Looking for individual differences within this group that may be responsible for more or less aggressive behavior, we identified genomic amplifications at the 8q22.1 and the 8q24.22 loci to be associated with enhanced gene transcription. Because we have previously shown that gains of genomic material from the long arm of chromosome 8 have an adverse effect on the outcome of pancreatic carcinoma patients, we conclude that functional analysis of amplified genes at 8q22 and/or 8q24 may lead to an improved understanding of pancreatic carcinoma progression.

A multicenter, randomized study of decitabine as epigenetic priming with induction chemotherapy in children with AML.

BACKGROUND: Decitabine is a deoxycytidine nucleoside derivative inhibitor of DNA-methyltransferases, which has been studied extensively and is approved for myelodysplastic syndrome in adults but with less focus in children. Accordingly, we conducted a phase 1 multicenter, randomized, open-label study to evaluate decitabine pre-treatment before standard induction therapy in children with newly diagnosed AML to assess safety and tolerability and explore a number of biologic endpoints. RESULTS: Twenty-four patients were fully assessable for all study objectives per protocol (10 in Arm A = epigenetic priming induction, 14 in Arm B = standard induction). All patients experienced neutropenia and thrombocytopenia. The most common grade 3 and 4 non-hematologic adverse events observed were gastrointestinal toxicities and hypophosphatemia. Plasma decitabine PK were similar to previously reported adult data. Overall CR/CRi was similar for the two arms. MRD negativity at end-induction was 85% in Arm A versus 67% in Arm B patients. DNA methylation measured in peripheral blood over the course of treatment tracked with blast clearance and matched marrow aspirates at day 0 and day 21. Unlike end-induction marrow analyses, promoter methylation in blood identified an apparent reversal of response in the lone treatment failure, 1 week prior to the patient's marrow aspirate confirming non-response. Decitabine-induced effects on end-induction (day 35-43 following initiation of treatment) marrows in Arm A were reflected by changes in DNA methylation in matched paired marrow diagnostic aspirates. CONCLUSIONS: This first-in-pediatrics trial demonstrates that decitabine prior to standard combination chemotherapy is feasible and well tolerated in children with newly diagnosed AML. Pre-treatment with decitabine may represent a newer therapeutic option for pediatric AML, especially as it appears to induce important epigenetic alterations. The novel biological correlates studied in this trial offer a clinically relevant window into disease progression and remission. Additional studies are needed to definitively assess whether decitabine can enhance durability responses in children with AML. TRIAL REGISTRATION: NCT01177540.

Chromosomal and genetic imbalances in synovial sarcoma detected by conventional and microarray comparative genomic hybridization.

PURPOSE: To analyze the relationship between chromosomal instabilities and clinicopathological factors in synovial sarcoma (SS). METHODS: Twenty-two fresh-frozen SS were analyzed by metaphase comparative genomic hybridization (CGH). Additional microarray CGH was performed in 13 cases. RESULTS: Fourteen patients with SYT-SSX1 rearrangements and nine patients with biphasic tumor subtypes had better prognosis than the eight patients with SYT-SSX2 rearrangements and 13 patients with monophasic subtypes, respectively. Gains (average 3.0) were more frequent than losses (average 1.0). Frequent gains were identified on chromosomal regions 2, 6q, 7, 8q, 12, 17q, 18q, and 21q, whereas frequent losses were over-lapped on chromosomes 1p31-p35, 3p, 6q, 16, and 17p. High-level gains were observed on chromosomes 1q21-q31, 7, 8, 12, 17q, 18q, and 21q. Thirteen monophasic and nine biphasic tumors had an average of 5.1 and 2.8 aberrations, respectively. Patients with tumors harboring numerous aberrations (>or=3) had a worse clinical course. Microarray CGH more specifically detected genetic imbalances including gains in MDM2, MSH2, KCNK12, DCC, CDK2, ERBB3, SAS, and CDK4 and losses in HRAS, RASSF1, and CCND1. Gain of SAS was an important prognostic factor of SS. CONCLUSION: We have identified several factors influencing the prognosis of SS patients by metaphase and microarray CGH.

Chromosomal imbalances in malignant peripheral nerve sheath tumor detected by metaphase and microarray comparative genomic hybridization.

Malignant peripheral nerve sheath tumors (MPNSTs) are highly malignant tumors affecting adolescents and adults. There have been a few reports on chromosomal aberrations of MPNSTs; however, the tumor-specific alteration remains unknown. We characterized the genomic alterations in 8 MPNSTs and 8 schwannomas by metaphase comparative genomic hybridization (CGH). In 5 of 8 MPNSTs, microarray CGH was added for more detailed analyses. Frequent gains were identified on 3q13-26, 5p13-14, and 12q11-23 and frequent losses were at 1p31, 10p, 11q24-qter, 16, and 17. Microarray CGH revealed frequent gains of EGFR, DAB2, MSH2, KCNK12, DDX15, CDK6, and LAMA3, and losses of CDH1, GLTSCR2, EGR1, CTSB, GATA3, and SULT2A1. These genes seem to be responsible for developing MPNSTs. The concordance rate between metaphase CGH and microarray CGH was 66%. Metaphase CGH was useful for identifying chromosomal alterations before applying microarray CGH.

Expression profiling of t(12;22) positive clear cell sarcoma of soft tissue cell lines reveals characteristic up-regulation of potential new marker genes including ERBB3.

Clear cell sarcoma of soft tissue (CCSST), also known as malignant melanoma of soft parts, represents a rare lesion of the musculoskeletal system usually affecting adolescents and young adults. CCSST is typified by a chromosomal t(12;22)(q13;q12) translocation resulting in a fusion between the Ewing sarcoma gene (EWSR1) and activating transcription factor 1 (ATF1), of which the activity in nontransformed cells is regulated by cyclic AMP. Our aim was to identify critical differentially expressed genes in CCSST tumor cells in comparison with other solid tumors affecting children and young adults to better understand signaling pathways regulating specific features of the development and progression of this tumor entity. We applied Affymetrix Human Genome U95Av2 oligonucleotide microarrays representing approximately 12,000 genes to generate the expression profiles of the CCSST cell lines GG-62, DTC-1, KAO, MST2, MST3, and Su-CC-S1 in comparison with 8 neuroblastoma, 7 Ewing tumor, and 6 osteosarcoma cell lines. Subsequent hierarchical clustering of microarray data clearly separated all four of the tumor types from each other and identified differentially expressed transcripts, which are characteristically up-regulated in CCSST. Statistical analysis revealed a group of 331 probe sets, representing approximately 300 significant (P < 0.001) differentially regulated genes, which clearly discriminated between the CCSST and other tumor samples. Besides genes that were already known to be highly expressed in CCSST, like S100A11 (S100 protein) or MITF (microphthalmia-associated transcription factor), this group shows an obvious portion of genes that are involved in cyclic AMP response or regulation, in pigmentation processes, or in neuronal structure and signaling. Comparison with other expression profile analyses on neuroectodermal childhood tumors confirms the high robustness of this strategy to characterize tumor entities based on their gene expression. We found the avian erythroblastic leukemia viral oncogene homologue 3 (ERBB3) to be one of the most dramatically up-regulated genes in CCSST. Quantitative real-time PCR and Northern blot analysis verified the mRNA abundance and confirmed the absence of the inhibitory transcript variant of this gene. The protein product of the member of the epidermal growth factor receptor family ERBB3 could be shown to be highly present in all of the CCSST cell lines investigated, as well as in 18 of 20 primary tumor biopsies. In conclusion, our data demonstrate new aspects of the phenotype and the biological behavior of CCSST and reveal ERBB3 to be a useful diagnostic marker.

Synergisitic and Antagonistic AML Cell Type-specific Responses to 5-Aza-2-deoxycitidine and 1-h-D-Arabinofuranoside.

BACKGROUND: The search for synergistic drug combinations is critical to the treatment of drug-resistant cancer, such as acute myeloid leukemia (AML). Characterizing RNA expression associated with 5-aza-2'-deoxycytidine (DAC) and 1-h-D-arabinofuranosylcytosine (Ara-C) is a critical step to increase the efficacy of their combinatorial therapies. MATERIALS AND METHODS: After 72 h of single-dose treatments of AML cells with DAC or Ara-C, the half-maximal effective concentration of DAC and Ara-C and the drug combination index were assessed. RESULTS: Pre-treatment with DAC restores cellular sensitivity in Ara-C-resistant AML cells. In contrast, DAC/Ara-C combinations are antagonistic in other Ara-C-sensitive AML cells. CONCLUSION: Our results provide an alternative approach for predicting what combinations, dosing and scheduling of drug delivery should be used to better individualize therapy of AML.

Genomic Profiling of Pediatric Acute Myeloid Leukemia Reveals a Changing Mutational Landscape from Disease Diagnosis to Relapse.

The genomic and clinical information used to develop and implement therapeutic approaches for acute myelogenous leukemia (AML) originated primarily from adult patients and has been generalized to patients with pediatric AML. However, age-specific molecular alterations are becoming more evident and may signify the need to age-stratify treatment regimens. The NCI/COG TARGET-AML initiative used whole exome capture sequencing (WXS) to interrogate the genomic landscape of matched trios representing specimens collected upon diagnosis, remission, and relapse from 20 cases of de novo childhood AML. One hundred forty-five somatic variants at diagnosis (median 6 mutations/patient) and 149 variants at relapse (median 6.5 mutations) were identified and verified by orthogonal methodologies. Recurrent somatic variants [in (greater than or equal to) 2 patients] were identified for 10 genes (FLT3, NRAS, PTPN11, WT1, TET2, DHX15, DHX30, KIT, ETV6, KRAS), with variable persistence at relapse. The variant allele fraction (VAF), used to measure the prevalence of somatic mutations, varied widely at diagnosis. Mutations that persisted from diagnosis to relapse had a significantly higher diagnostic VAF compared with those that resolved at relapse (median VAF 0.43 vs. 0.24, P < 0.001). Further analysis revealed that 90% of the diagnostic variants with VAF >0.4 persisted to relapse compared with 28% with VAF <0.2 (P < 0.001). This study demonstrates significant variability in the mutational profile and clonal evolution of pediatric AML from diagnosis to relapse. Furthermore, mutations with high VAF at diagnosis, representing variants shared across a leukemic clonal structure, may constrain the genomic landscape at relapse and help to define key pathways for therapeutic targeting. Cancer Res; 76(8); 2197-205. ©2016 AACR.

Doxorubicin modulates telomerase activity in Ewing's sarcoma in vitro and in vivo.

Since most tumours escape replicative senescence by re-activation of the enzyme telomerase, telomerase is a promising target in the treatment of cancer and a promising marker for diagnosis and therapeutic response. We evaluated the effects of doxorubicin, one of the most active drugs in the treatment of Ewing's sarcoma, on telomerase in the human Ewing's sarcoma cell line STA-ET-1 in vitro and in STA-ET-1 xenografts in vivo. Telomerase activity (TA) was examined by TRAP-assay and real-time PCR. Real-time PCR was also used to quantify the mRNA expression of the catalytic subunit of telomerase (hTERT). In vitro growth inhibition was determined by the MTT-assay. Tumour xenografts were analyzed for tumour volume, apoptosis, necrosis, and proliferation. Doxorubicin concentrations that inhibited in vitro growth of STA-ET-1 by 50% compared to untreated controls ranged between 0.14 microM after 24 h and 0.01 microM after 72 h. Compared to untreated controls doxorubicin reduced TA in STA-ET-1 at toxic concentrations, but increased TA at non-toxic concentrations. In comparison with untreated xenografts, TA was reduced to 65% and hTERT expression dropped to 25% within 72 h in xenografts treated with 17.5 mg/kg doxorubicin i.p.; both recovered to initial values after 264 h. The rate of proliferating cells dropped to 70% within 96 h and increased thereafter. The highest rates of necrosis and apoptosis were seen after 96 h. hTERT expression co-varied significantly with proliferation but not with TA, apoptosis, and necrosis. No correlation was observed between TA, proliferation, apoptosis and necrosis. The results suggest doxorubicin induces down-regulation of hTERT gene expression that at least in part modulates TA in these tumours.

Can we apply the National Cholesterol Education Program Adult Treatment Panel definition of the metabolic syndrome to Asians?

OBJECTIVE: Limited information is available about the metabolic syndrome in Asians. Furthermore, the definition of central obesity using waist circumference may not be appropriate for Asians. The objectives of this study were to determine the optimal waist circumference for diagnosing central obesity in Asians and to estimate the prevalence of the metabolic syndrome in an Asian population. RESEARCH DESIGN AND METHODS: We used data from the 1998 Singapore National Health Survey, a cross-sectional survey involving 4,723 men and women of Chinese, Malay, and Asian-Indian ethnicity aged 18-69 years. Receiver operating characteristic analysis suggested that waist circumference >80 cm in women and >90 cm in men was a more appropriate definition of central obesity in this population. The prevalence of the metabolic syndrome was then determined using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria with and without the modified waist circumference criteria. RESULTS: In Asians, decreasing waist circumference increased the crude prevalence of the metabolic syndrome from 12.2 to 17.9%. Using the modified Asian criteria, the prevalence of the metabolic syndrome increased from 2.9% in those aged 18-30 years to 31.0% in those aged 60-69 years. It was more common in men (prevalence 20.9% in men versus 15.5% in women; P < 0.001) and Asian Indians (prevalence 28.8% in Asian-Indians, 24.2% in Malays, and 14.8% in Chinese; P < 0.001). CONCLUSIONS: NCEP ATP III criteria, applied to an Asian population, will underestimate the population at risk. With a lower waist circumference cutoff, the prevalence of the metabolic syndrome is comparable to that in Western populations. Ethnic differences are likely to exist between populations across Asia.

Expression analysis of pediatric solid tumor cell lines using oligonucleotide microarrays.

We identified patterns of differentially-expressed genes in cell lines derived from several pediatric solid tumors. Affymetrix Human Cancer G110 Arrays, carrying 1,700 cancer-associated genes, were applied to a panel of 11 cell lines originating from Ewing tumors (ETs), neuroblastomas, and malignant melanoma of soft parts. Hierarchical clustering clearly differentiated these 3 entities and revealed groups of 75, 102, and 36 gene probe-sets exhibiting tumor-type specific up-regulation in these cell lines, respectively. Whereas ET lines demonstrated increased expression of microtubule-associated protein tau (MAPT), protein phosphatase 1 regulatory subunit 1A (PPP1R1A), NIMA (never in mitosis gene a)-related kinase 2 (NEK2), and cyclin D1 (CCND1), neuroblastoma samples exhibited high expression of wingless-type mouse mammary tumor virus integration site family member 11 (WNT11), Drosophila frizzled homolog 2 (FZD2), and adenomatous polyposis coli (APC) which are involved in regulating free beta-catenin levels. These genes likely maintain tumor-specific characteristics and participate in key downstream regulatory mechanisms. We also correlated the expression levels of up-regulated genes in ETs with their chromosomal localization and compared these data to the comparative genomic hybridization profiles of the cell lines. We demonstrate that gains of genetic material contribute essentially to differential gene expression.

Characterization of the malignant melanoma of soft-parts cell line GG-62 by expression analysis using DNA microarrays.

GG-62 is a cell line previously thought to be derived from an atypical Ewing tumor (ET). Reverse-transcriptase polymerase chain reaction revealed an in-frame fusion between the Ewing sarcoma gene ( EWS) codon 325 and the activating transcription factor 1 gene ( ATF1) codon 65 which permits the production of chimeric EWS-ATF1 oncoproteins. We also identified the genomic breakpoint resulting from a reciprocal t(12;22)(q13;q12), which is the hallmark of malignant melanoma of soft parts (MMSP). We applied Affymetrix human cancer G110 arrays to compare the gene expression patterns of GG-62 and other cell lines derived from small blue round cell tumors of childhood. Hierarchical clustering of 463 differentially expressed genes distinguished GG-62 from the ETs, as well as the neuroblastomas, and revealed a cluster of 36 upregulated genes. Several of these genes are involved in signal transduction pathways that may be critical for maintaining cell transformation; some examples are avian erythroblastic leukemia viral oncogene homolog 3 ( ERBB3), neuregulin 1 ( NRG1), fibroblast growth factor 9 ( FGF9), and fibroblast growth factor receptor-1 ( FGFR1). Furthermore, genes near the chromosome-12q13 breakpoint exhibited increased expression of GG-62 including ERBB3, NR4A1 (nuclear receptor subfamily 4, group A, member 1), cyclin-dependent kinase 2 ( CDK2), and alpha 5 integrin ( ITGA5). Altogether our findings demonstrate the MMSP derivation of GG-62 and may shed light on the mechanisms of tumorigenesis in this rare disease.

Chromosomal alterations in osteosarcoma cell lines revealed by comparative genomic hybridization and multicolor karyotyping.

We characterized the chromosomal alterations in eight osteosarcoma cell lines (OST, HOS, U-2 OS, ZK-58, MG-63, SJSA-1, Saos-2, and MNNG) by comparative genomic hybridization (CGH); gains and losses of DNA sequences were defined as chromosomal regions with a fluorescence ratio, wherein all of the 95% confidence interval was above 1.25 and below 0.75, respectively. In four of 8 cell lines, multicolor karyotyping (MK) was added. CGH revealed the average number of aberrations per cell line was 20.8 (range: 10-31); the average numbers of gains and losses were 11.1 and 9.6, respectively. The frequent gains were identified on 1p21 approximately q24, 1q25-q31, 7p21, 7q31, 8q23 approximately q24, and 14q21; frequent losses were at 18q21 approximately q22, 18q12, 19p, and 3p12 approximately p14. High-level gains were observed on 8q23 approximately q24, 5p, and 1p21 approximately p22. MK revealed the most common translocations in the four cell lines were t(8;9), t(1;3), t(3;5), t(1;13), t(2;6), t(3; 17), t(1;15), t(10;20), and t(6;20). Chromosomes 1, 3, 8, 9, and 20 were most frequently involved in translocation events. The concordance rate of aberrations in CGH and translocations in MK was 76%. MK was useful to identify the chromosomal alterations and as a supplement to the CGH results in three of four chromosomes.

Severe Graves' ophthalmopathy after retrobulbar anesthesia for cataract extraction in a patient with mild stable thyroid eye disease.

It has been hypothesized that the distinct anatomic localization of the Graves' triad may be partially explained by pressure and trauma. While there are reports of local trauma clearly contributing to the pathogenesis of pretibial myxedema, direct evidence for a similar mechanism in Graves' ophthalmopathy (GO) has been lacking. We describe a 65-year-old male patient with stable mild Graves' ophthalmopathy of 24 years' duration in whom a retrobulbar block was administered prior to cataract removal. Three weeks after the procedure, he complained of rapidly progressive bilateral diplopia. In 6 months, there was moderate exophthalmos, exposure keratitis, almost complete ophthalmoplegia, and decreasing visual acuity requiring surgical decompression. Postdecompression, inflammatory signs and vision improved but there was complete ophthalmoplegia. The eye signs remained unchanged for the next 4 months but there was exacerbation of the disease within a week of receiving radioiodine despite concomitant steroid administration. Orbital irradiation was finally administered with rapid improvement in extraocular eye muscle function. We hypothesize that local inflammatory and immune responses stimulated by trauma and/or pressure in the retrobulbar compartment, triggered the development of severe ophthalmopathy in this patient. Thyroid-stimulating immunoglobulin (TSI) levels remained markedly elevated despite the clinical improvement suggesting that the beneficial effects of radiotherapy in this case were not mediated by suppressing TSI production.

Comparative genomic hybridization in cartilaginous tumors.

Genetic aberrations in cartilaginous tumors have not yet been well characterized. We analyzed the molecular-chromosomal aberrations in 10 chondrosarcomas (four Grade-3 tumors, four Grade-2 tumors and two Grade-1 tumors) and in three benign cartilaginous tumors (two enchondromas and one chondromyxoid fibroma). Genomic imbalances were detected in 9 out of 10 cases of chondrosarcomas. The median number of changes was 7.0 per tumor (range 0-23) and the gain-to-loss ratio was 1:1.4. The most frequent gains involved 7q, 5p, or 21q and the most frequent losses were 17p, 13q, 16p, or 22q. The three benign cartilaginous tumors each had two (0 gains and two losses), six (one gain and five losses) and eight (one gain and seven losses) chromosomal aberrations. Both of the gains occurred on 13q21 and losses were frequently observed on chromosomes 19 and 22q in all three cases. Loss of chromosomes 16p, 17p, 22q, or 19 loss were common in both chondrosarcomas and benign cartilaginous tumors. However, aberrations from chromosomes 2 to 11, 14, 15, 18, or 21 were detected only in chondrosarcomas. Therefore, although the number of aberrations between benign and malignant cartilaginous tumors appears to be similar, these two entities may be differentiated by determining which chromosomes are affected.

FOXM1 is an oncogenic mediator in Ewing Sarcoma.

Ewing Family Tumors (Ewing Sarcoma and peripheral Primitive Neuroectodermal Tumor) are common bone and soft tissue malignancies of childhood, adolescence and young adulthood. Chromosomal translocation in these tumors produces fusion oncogenes of the EWS/ETS class, with EWS/FLI1 being by far the most common. EWS/ETS chimera are the only well established driver mutations in these tumors and they function as aberrant transcription factors. Understanding the downstream genes whose expression is modified has been a central approach to the study of these tumors. FOXM1 is a proliferation associated transcription factor which has increasingly been found to play a role in the pathogenesis of a wide range of human cancers. Here we demonstrate that FOXM1 is expressed in Ewing primary tumors and cell lines. Reduction in FOXM1 expression in Ewing cell lines results in diminished potential for anchorage independent growth. FOXM1 expression is enhanced by EWS/FLI1, though, unlike other tumor systems, it is not driven by expression of the EWS/FLI1 target GLI1. Thiostrepton is a compound known to inhibit FOXM1 by direct binding. We show that Thiostrepton diminishes FOXM1 expression in Ewing cell lines and this reduction reduces cell viability through an apoptotic mechanism. FOXM1 is involved in Ewing tumor pathogenesis and may prove to be a useful therapeutic target in Ewing tumors.

Prevalence and control of hypercholesterolaemia as defined by NCEP-ATPIII guidelines and predictors of LDL-C goal attainment in a multi-ethnic Asian population.

INTRODUCTION: Few studies in Asia have assessed the burden of hypercholesterolaemia based on the global cardiovascular risk assessment. This study determines the burden of hypercholesterolaemia in an Asian population based on the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATPIII) guidelines, and examines predictors of low-density lipoprotein cholesterol (LDL-C) goal attainment. MATERIALS AND METHODS: Five thousand and eighty-three Chinese, Malays and Asian-Indians living in Singapore were assigned to coronary heart disease (CHD)-risk category based on the NCEP-ATPIII guidelines. Awareness, treatment and control of hypercholesterolaemia based on risk- specific LDL-C goal were determined, including the use of lipid-lowering therapy (LLT). Cox-regression models were used to identify predictors of LDL-C above goal among those who were aware and unaware of hypercholesterolaemia. RESULTS: One thousand five hundred and sixty-eight (30.8%) participants were aware of hypercholesterolaemia and 877 (17.3%) were newly diagnosed (unaware). For those who were aware, 39.3% participants received LLT. Among those with 2 risk factors, only 59.7% attained LDL-C goal. The majority of them were taking statin monotherapy, and the median dose of statins was similar across all CHD risk categories. Among participants with 2 risk factors and not receiving LLT, 34.1% would require LLT. Malays or Asian-Indians, higher CHD risk category, increasing body mass index (BMI), current smoking and lower education status were associated with higher risk of LDL-C above goal. Being on LLT reduced the risk of having LDL-C above goal. CONCLUSION: The burden of hypercholesterolaemia is high in this multi-ethnic population especially those in the higher CHD risk categories, and might be partly contributed by inadequate titration of statins therapy. Raising awareness of hypercholesterolaemia, appropriate LLT initiation and titration, weight management and smoking cessation may improve LDL-C goal attainment in this population.