Factors associated with depression and anxiety in children with intellectual disabilities.

BACKGROUND: Individuals with intellectual disabilities (ID) are at increased risk for depression and anxiety disorders; however, there is a paucity of research that pertains to associative factors for these mental health disorders in this population. The objective of this investigation was to determine factors associated with depression and anxiety problems in children with ID. METHODS: Children 6-17 years with ID (n = 423; 63% male) from the 2016 National Survey of Children's Health were included in this cross-sectional study. Outcome measures included depression and anxiety problems. Predictor variables included sociodemographics, ID severity, co-morbid conditions (autism spectrum disorders, epilepsy, cerebral palsy, Down syndrome and attention-deficit/hyperactivity disorder), physical factors (i.e. physical activity, sleep duration and pain) and social factors (e.g. participation in activities and bully victimisation). Multivariable logistic regression was performed to determine the association between all factors and depression and/or anxiety problems among children with ID. RESULTS: The prevalence of depression and/or anxiety problems was 35.4%. After adjusting for sociodemographics, Hispanic race was associated with lower odds [odds ratio (OR), 0.3; 95% confidence interval (CI), 0.1-0.8] of depression and/or anxiety problems. After adjusting for race, co-morbid conditions, and physical and social factors, autism spectrum disorders (OR, 4.4; 95% CI, 1.1-10.1), Down syndrome (OR, 0.2; 95% CI, 0.1-0.8), attention-deficit/hyperactivity disorder (OR, 5.9; 95% CI, 2.5-14.3), pain (OR, 7.0; 95% CI, 2.9-17.1) and bully victimisation (OR 2.3; 95% CI, 1.0-5.3) were each associated with depression and/or anxiety problems. CONCLUSIONS: The present study identified both treatable and modifiable, as well as unmodifiable, factors associated with depression and/or anxiety problems in children with ID.

Phylogenetically interrelated ETS genes, ETV1, ERM and E1A-F locate on different chromosomes.

ETV1, ERM and E1A-F are members of the multigene ETS domain containing a class of transcription factors, first identified in the genome of the avian retrovirus E26. Based upon extensive homology between these genes within their ETS domain (96% identity each other), these three genes comprise a distinct sub-family of ETS genes as a human PEA3 sub-family. By analyzing somatic cell hybrid segregating human chromosomes, the genes encoding ETV1, ERM and E1A-F were localized to human chromosome 7, 3 and 17, respectively. Fluorescence in situ hybridization confirmed these assignments and allowed mapping of the genes to 7p22 (ETV1), 3q29 (ERM) and 17q12 (E1A-F). These results suggest the ancestral PEA3 gene may have duplicated first, then dispersed to other chromosomal locations.

A phase II trial of high-dose methotrexate in previously untreated children and adolescents with high-risk unresectable or metastatic rhabdomyosarcoma.

PURPOSE: The outcome for children with advanced-stage rhabdomyosarcoma remains poor with contemporary treatment regimens. Evaluation of new drugs is important to improve clinical outcome. Because methotrexate has shown promising activity in the treatment of patients with recurrent rhabdomyosarcoma, we conducted a phase II trial in untreated children with advanced-stage disease to evaluate the efficacy and safety of this agent. PATIENTS AND METHODS: Fifteen patients received 1 to 4 courses of high-dose methotrexate (HDMTX, 12 g/m2). Patients then received standard multiagent chemotherapy (vincristine, dactinomycin, cyclophosphamide, ifosfamide, mesna) with cytokine support and local radiotherapy. Patients who responded to HDMTX received four additional courses of this drug during continuation therapy. RESULTS: Twelve patients were evaluable for response after 2 or more courses of HDMTX; 4 achieved a partial response (33.3%). After administration of standard chemotherapy and radiation, the estimated 2-year progression-free survival for all patients was 56% (SD 15%). The drug was well-tolerated and the most common side effects included mucositis, transient elevation of transaminases, and neutropenia. The four patients who received additional courses of HDMTX during continuation therapy had limited toxicity which included mucositis, anemia, and thrombocytopenia. CONCLUSIONS: About one-third of children with previously untreated advanced-stage rhabdomyosarcoma responded to HDMTX. Its different mechanism of action and non-overlapping toxicity with other agents make HDMTX an attractive candidate for incorporation into front-line treatment regimens for rhabdomyosarcoma.

Extensive genomic abnormalities in childhood medulloblastoma by comparative genomic hybridization.

We analyzed 27 samples of primary medulloblastoma, using comparative genomic hybridization and a novel statistical approach to evaluate chromosomal regions for significant gain or loss of genomic DNA. An array of nonrandom changes was found in most samples. Two discrete regions of high-level DNA amplification of chromosome bands 5p15.3 and 11q22.3 were observed in 3 of 27 tumors. Nonrandom genomic losses were most frequent in regions on chromosomes 10q (41% of samples), 11 (41%), 16q (37%), 17p (37%), and 8p (33%). Regions of DNA gain most often involved chromosomes 17q (48%) and 7 (44%). These findings suggest a greater degree of genomic imbalance in medulloblastoma than has been recognized previously and highlight chromosomal loci likely to contain oncogenes or tumor suppressor genes that may contribute to the molecular pathogenesis of this tumor.

Rhabdomyosarcoma. Biology and treatment.

Rhabdomyosarcoma is the most common soft-tissue sarcoma of childhood. Recognition of specific genetic changes in the two most common subtypes of rhabdomyosarcoma has allowed better understanding of the pathogenesis of this disease. In addition, identification of prognostic factors and the use of risk-directed multimodal therapy have improved the outcome for these patients significantly, with cure rates approaching 70%.

Identification of novel regions of deletion in familial Wilms' tumor by comparative genomic hybridization.

Wilms' tumor, an embryonic renal neoplasm diagnosed primarily in young children, can occur in either a noninheritable (sporadic) or a familial form, with the latter presenting earlier and more often at bilateral sites. Although familial Wilms' tumor is thought to develop through inherited and acquired mutational inactivation of the two alleles of predisposing tumor suppressor genes, only a small percentage of cases can be accounted for by mutations affecting the WT1 gene or linkage to the Beckwith-Weidemann syndrome of the BWS region on the short arm of chromosome 11. To find chromosomal regions that might contain genes important in the development of this disease, we used comparative genomic hybridization to analyze tumor specimens from familial cases for chromosomal regions that were consistently lost. Although inherited lesions of tumor suppressors are most often inactivating point mutations, accompanying somatic lesions in the malignant clones are often chromosomal deletions; therefore, consensus regions of loss in familial tumors are likely to harbor genes linked to familial predisposition. There were extensive genomic aberrations among the eight familial cases studied, with an average of 6.5 changes/tumor (range, 0-22). The most consistent findings with likely biological relevance were deletions of chromosomes 4 (consensus, 4q21-qter), 9 (consensus, 9p21-pter), 20p, and 3 (consensus, 3q12-q21). These regions have not been previously implicated in Wilms' tumor and may harbor novel genes that could aid attempts to understand the familial predisposition as well as the development and progression of these tumors.

Der(16)t(1;16)(q21;q13) in Wilms' tumor: friend or foe.

The der(16)t(1;16)(q21;q13) chromosomal abnormality has been reported rarely in Wilms' tumor. This abnormality has also been found in several other pediatric and adult neoplasms, and may imply a poor prognosis in at least some of these solid tumors. To investigate its clinical significance in Wilms' tumor, we examined the records of 65 consecutive children with Wilms' tumor whose tumor cells were successfully karyotyped. The t(1;16) was present in seven patients (10%) whose ages ranged from 2.5 to 4.7 years (median 3.5 years) at diagnosis. Six of the seven patients were female. All four stages of Wilms' tumor were represented (two patients had stage IV disease). No patient had bilateral disease. All tumors were of "favorable histology." All seven patients are alive and off therapy with a median follow-up of 3.2 years (range, 2 to 8.5 years). One patient with this abnormality developed brain metastases within 4 months of completion of therapy. Comparison of these patients with the remaining 58 Wilms' tumor patients revealed no significant differences with regard to disease stage, histology, survival, or relapse-free survival. Cytogenetic evidence of der(16)t(1;16)(q21;q13) in Wilms' tumor does not appear to portend an adverse clinical outcome, although only a larger study that includes molecular detection methods can provide more conclusive evidence.

The gene encoding LERK-7 (EPLG7, Epl7), a ligand for the Eph-related receptor tyrosine kinases, maps to human chromosome 5 at band q21 and to mouse chromosome 17.

The eph-related receptors are the largest subfamily of receptor tyrosine kinases. Recently, we and others have identified seven different, but related, cDNAs encoding membrane-bound ligands for this family of receptors. One member, LERK-7, is attached to the cell membrane via glycosyl-phosphatidylinositol linkage and has been found to be a ligand for the eph-family receptors hek, elk, eck, and rek. Using PCR-based screening of human x rodent somatic cell hybrid DNAs, we have assigned the gene that encodes LERK-7 (EPLG7) to human chromosome 5. Fluorescence in situ hybridization to metaphase chromosome preparations using a genomic clone from the locus refined this localization to chromosome 5, band q21. In addition, Southern blot analysis of DNAs from interspecific backcross mice indicated that the mouse homologue Epl7 maps to a homologous region on chromosome 17.

The genes encoding the eph-related receptor tyrosine kinase ligands LERK-1 (EPLG1, Epl1), LERK-3 (EPLG3, Epl3), and LERK-4 (EPLG4, Epl4) are clustered on human chromosome 1 and mouse chromosome 3.

Hek and elk are members of the eph-related family of receptor tyrosine kinases. Recently, we isolated five cDNAs encoding membrane-bound ligands to hek and elk. Because of the promiscuous nature of their binding, we have termed these proteins ligands of the eph-related kinases or LERKs. The LERKs can be divided into two subgroups by virtue of their sequence identity, binding properties, and mode of cell membrane attachment. For example, LERK-2 (EPLG2, Epl2) and LERK-5 (EPLG5, Epl5) are type 1 transmembrane proteins, while LERK-1 (EPLG1, Epl1), LERK-3 (EPLG3, Epl3), and LERK-4 (EPLG4, Epl4) are anchored to the membrane by glycosyl-phosphatidylinositol (GPI) linkage. Using Southern hybridization analysis of human x rodent somatic cell hybrid DNAs, we have assigned the genes that encode the GPI-anchored LERKs (EPLG1, EPLG3, and EPLG4) to human chromosome 1. Fluorescence in situ hybridization to metaphase chromosome preparations using genomic clones from each locus refined this localization to chromosome 1, bands q21-q22. In addition, Southern blot analysis of DNA from interspecific backcross mice indicated that the mouse homologues Epl1, Epl3, and Epl4 map to a homologous region on mouse chromosome 3.

Pax3 modulates expression of the c-Met receptor during limb muscle development.

Pax3 is a transcription factor whose expression has been used as a marker of myogenic precursor cells arising in the lateral somite destined to migrate to and populate the limb musculature. Accruing evidence indicates that the embryologic origins of axial and appendicular muscles are distinct, and limb muscle abnormalities in both mice and humans harboring Pax3 mutations support this distinction. The mechanisms by which Pax3 affects limb muscle development are unknown. The tyrosine kinase receptor for hepatocyte growth factor/scatter factor encoded by the c-met protooncogene is also expressed in limb muscle progenitors and, like Pax-3, is required in the mouse for limb muscle development. Here, we show that c-met expression is markedly reduced in the lateral dermomyotome of Splotch embryos lacking Pax3. We show that Pax3 can stimulate c-met expression in cultured cells, and we identify a potential Pax3 binding site in the human c-MET promoter that may contribute to direct transcriptional regulation. In addition, we have found that several cell lines derived from patients with rhabdomyosarcomas caused by a t(2;13) chromosomal translocation activating PAX3 express c-MET, whereas those rhabdomyosarcoma cell lines examined without the translocation do not. These results are consistent with a model in which Pax3 modulates c-met expression in the lateral dermomyotome, a function that is required for the appropriate migration of these myogenic precursors to the limb where the ligand for c-met (hepatocyte growth factor/scatter factor) is expressed at high levels.

P-glycoprotein expression at diagnosis may not be a primary mechanism of therapeutic failure in childhood rhabdomyosarcoma.

PURPOSE: To evaluate the prognostic significance of tumor cell P-glycoprotein (Pgp) expression at diagnosis in children with rhabdomyosarcoma. PATIENTS AND METHODS: A panel of three anti-Pgp monoclonal antibodies (mAb) (C219, C494, and JSB-1) that recognize different Pgp epitopes was used to measure Pgp expression in rhabdomyosarcoma specimens obtained at diagnosis from 76 patients treated at St Jude Children's Research Hospital from 1969 to 1991. Two separate experiments using different immunohistochemical methods (immune alkaline phosphatase and immunoperoxidase) were performed to evaluate Pgp expression. The immunostaining was graded using a semiquantitative scale corresponding to the percentage of tumor cells with detectable staining. The influence of Pgp expression on outcome was assessed by the Kaplan-Meier method and Cox regression analysis with stepwise selection. The relationship between Pgp expression and clinical features was assessed using the Mantel-Haenszel method. RESULTS: Pgp expression at diagnosis did not predict worse overall survival or progression-free survival when tested in either experiment with C219, C494, or JSB-1 separately. No association was shown between Pgp expression and clinical features (clinical group, primary site, or histology) or response. However, in the immune alkaline phosphatase experiment, patients whose tumors had more than 10% tumor cell staining with all three mAbs had a significantly higher rate of estimated 5-year survival (78% +/- 10%) than did all other patients (38% +/- 8%; P = .025). In this instance, Pgp expression had independent prognostic value after adjusting for clinical group. CONCLUSION: We found no strong association between Pgp expression at diagnosis and clinical features or extent of disease in pediatric rhabdomyosarcoma. Depending on the criteria used to define it, high Pgp expression at diagnosis does not predict poor outcome. Although a large prospective study is needed to provide definitive conclusions, our findings suggest that Pgp-mediated multidrug resistance may not be a primary mechanism of therapeutic failure in rhabdomyosarcoma.

The gene for calcium-modulating cyclophilin ligand (CAMLG) is located on human chromosome 5q23 and a syntenic region of mouse chromosome 13.

The CAMLG gene encodes a novel cyclophilin B-binding protein called calcium-modulating cyclophilin ligand, which appears to be involved in the regulation of calcium signaling in T lymphocytes and other cells. The murine homolog, Caml, was localized by interspecific backcross analysis to the middle of chromosome 13. By fluorescence in situ hybridization, this gene was localized to human chromosome 5 in a region (q23) known to be syntenic to mouse chromosome 13. These results provide further evidence supporting the extensive homology between human chromosome 5q and mouse chromosome 13. In addition, the results will provide a basis for further evaluation of cytogenetic anomalies that may contribute to inherited defects in calcium signaling or immune system function.

The gene encoding p120cas, a novel catenin, localizes on human chromosome 11q11 (CTNND) and mouse chromosome 2 (Catns).

The p120cas gene encodes a protein tyrosine kinase substrate that associates with the cell-cell adhesion protein complex containing E-cadherin and its cytoplasmic cofactors alpha-catenin, beta-catenin, and plakoglobin. Like other components of the cadherin/catenin complex, defects in p120cas may contribute to cell malignancy. We have determined the chromosomal location of the p120cas gene in human and mouse using fluorescence in situ hybridization and interspecific backcross analysis, respectively. The human p120cas gene (CTNND) is localized immediately adjacent to the centromere on the long arm of chromosome 11 in band 11q11. The murine p120cas gene (Catns) was assigned to the middle of chromosome 2. Neither locus is currently known to be associated with disease or malignancy.

Loss of imprinting of IGF2 in Ewing's sarcoma.

Insulin-like Growth Factor 2 (IGF2) has recently been demonstrated to be maternally imprinted in both mice and humans. We previously reported loss of imprinting (LOI) of IGF2 in rhabdomyosarcoma (RMS) where IGF2 has been shown to act as an autocrine growth factor and play an important role in pathogenesis. Since IGF2 does not appear to play a role in the pathogenesis of Ewing's sarcoma, we sought to determine whether normal IGF2 imprinting was maintained in these tumors. Of 32 Ewing's tumors examined for imprinting of IGF2, 10 were informative heterozygotes and three of these expressed IGF2 biallelically. Furthermore, all three tumors with LOI and five of seven tumors with normal imprinting transcribed IGF2 mRNA at lower levels while relatively higher levels of IGF2 expression was observed in the remaining two tumors with normal imprinting. These data demonstrate altered imprinting of IGF2 occurs in some Ewing's sarcomas. However, LOI of IGF2 in Ewing's sarcoma was not associated with increased expression of IGF2 mRNA, suggesting that LOI may not be involved in the regulation of IGF2 expression and may be related to genetic or epigenetic abnormalities in tumors independent of IGF2 expression.

The alveolar rhabdomyosarcoma PAX3/FKHR fusion protein is a transcriptional activator.

Chimeric transcription factors, created by gene fusions as the result of chromosomal translocations, have been implicated in the pathogenesis of several pathologically disparate solid tumors. The PAX3/FKHR fusion gene, formed by a t(2;13)(q35;q14) in alveolar rhabdomyosarcoma, encodes a hybrid protein that contains both PAX3 DNA binding domains, the paired box and homeodomain, linked to the bisected DNA binding domain of FKHR, a member of the forkhead family of transcription factors. Here we report that PAX3 and PAX3/FKHR display similar, but not identical transactivation activities when tested with model Pax recognition sequences. No functional role could be ascribed solely to the residual FKHR binding domain present in the fusion protein, but FKHR was found to contribute a strong carboxyl terminal activation domain replacing the one located in the unrearranged PAX3 gene. We show that the native PAX3/FKHR protein present in tumor cells with this translocation has transcriptional characteristics similar to the in vitro expressed protein. The ability of the PAX3/FKHR hybrid protein to bind DNA in a sequence specific manner and to transactivate the expression of artificial reporter genes suggests that its aberrant expression could subvert the transcriptional programs that normally control the growth, differentiation, and survival of primitive myogenic precursors in vivo.

Biology and therapy of pediatric rhabdomyosarcoma.

PURPOSE: To review key developments in biology and therapy of rhabdomyosarcoma (RMS) since the early 1970s. PATIENTS AND METHODS: The literature regarding biology, therapy, and late effects of therapy through March 1995 was reviewed. RESULTS: The two major histiotypes, embryonal and alveolar, are characterized by specific genetic abnormalities that provide clues to mechanisms of tumor induction. Alveolar tumors, for example, often possess a chromosomal translocation [t(2;13)(q35;q14)] that fuses the PAX3 gene in band 2q35 with the FKHR gene in band 13q14, creating a novel chimeric protein that could inappropriately activate normal targets of the PAX3 gene product, thereby contributing to tumorigenesis. Recognition of prognostically important patient groups primarily identified by tumor extent, site, and histology, and development of effective risk-based multimodal therapy in randomized trials, have increased long-term survival in RMS from 25% in 1970 to more than 70% in current studies. The most significant recent gain in therapeutic results was realized in patients with gross residual tumor after biopsy. CONCLUSION: Contemporary risk-based therapy cures more than two thirds of children with RMS while minimizing acute and late effects. Increased dose-intensity of known effective agents with hematopoietic growth factor support, new agents, and hyperfractionated irradiation are being evaluated in hopes of further improving therapy. Recent discovery of novel genetic features in this tumor should lead to better methods of diagnosis and risk assessment, and ultimately to identification of molecular targets for specific treatment.

Pax3 inhibits myogenic differentiation of cultured myoblast cells.

Pax3 is an evolutionarily conserved transcription factor expressed in the lateral dermomyotome, a region that gives rise to limb muscle progenitors. Mutations in Pax-3 account for the mouse mutant Splotch which develops without limb musculature. We demonstrate that Pax3 can inhibit myogenic differentiation of C2C12 myoblasts normally induced by exposure to low serum. Specific missense mutations that affect the DNA binding characteristics of the two distinct DNA binding domains of Pax3 abolish this effect. Furthermore, we show that Pax3 can inhibit myogenic differentiation of 10T1/2 fibroblasts transfected with MyoD, but not of 10T1/2 cells transfected with myogenin. This anti-myogenic property is shared by a PAX3-forkhead fusion protein resulting from a t(2;13) chromosomal translocation found in pediatric alveolar rhabdomyosarcomas. These results suggest that Pax3 may suppress the terminal differentiation of migrating limb myoblasts and that the PAX3-forkhead fusion may contribute to the phenotype of alveolar rhabdomyosarcoma by preventing terminal differentiation.