Interviews with parents of adolescents with intellectual and developmental disabilities in a weight management study.

BACKGROUND: Adolescents and young adults with intellectual and developmental disabilities are at risk of obesity. Parents influence their diet and physical activity behaviours and therefore, can play important roles in weight management. The aims of this qualitative study were to explore parents' experiences assisting their son or daughter to participate in a weight management study. METHODS: Interviews were completed at 6 months with 27 parents whose adolescent or young adult had completed the weight loss portion of an 18-month weight management study. Interviews were recorded, transcribed and thematic analysis performed. RESULTS: Parents shared insights about how well program components worked with their family, and what strategies worked best to adopt healthier dietary choices and become more physically active. The importance of meeting regularly with someone outside the family to encourage healthier habits was stressed. CONCLUSIONS: Future weight management studies should involve parents and their adolescents to help tailor strategies and adapt intervention approaches.

A randomized trial comparing diet and delivery strategies for weight management in adolescents with intellectual disabilities.

BACKGROUND: The literature evaluating multi-component interventions for long-term weight loss in adolescents with intellectual disabilities (ID) is extremely limited. OBJECTIVES: To compare the effectiveness of two delivery strategies, face-to-face (FTF) or remote delivery (RD), and two diets, enhanced Stop Light diet (eSLD) or conventional diet (CD) on weight change across 12 and 18 months. in response to an 18 months. weight management intervention (6 months Weight loss/12 months. Weight maintenance) in adolescents with ID. METHODS: Adolescents with ID were randomized to one of three arms: FTF /CD, RD/CD, RD/eSLD and asked to attend individual education sessions with a health educator which were delivered during FTF home visits or remotely using video conferencing. The CD followed the US dietary guidelines. The eSLD utilized the Stop Light guide and was enhanced with portion-controlled meals. Participants were also asked to increase their physical activity (PA) and to self-monitor diet, PA and body weight across the 18-month. RESULTS: Weight was obtained from 92(84%) and 89(81%) randomized adolescents at 12 and 18 months, respectively. Weight change across 12 months. Differed significantly by diet (RD/eSLD: -7.0% vs. RD/CD: -1.1%, p = 0.002) but not by delivery strategy (FTF/CD: +1.1% vs. RD/CD: -1.1%, p = 0.21). Weight change across 18 months. Was minimal in all intervention arms and did not differ by diet (RD/eSLD: -2.6% vs. RD/CD: -0.5%; p = 0.28) or delivery strategy (FTF/CD: +1.6% vs. RD/CD: -0.5%; p = 0.47). CONCLUSIONS: Additional research is required to identify effective strategies to improve long-term weight loss in adolescents with ID.

Inhibition of all-trans retinoic acid-induced granulocytic differentiation of WEHI-3B D+ cells by forced expression of SCL (TAL1) and GATA-1.

All-trans retinoic acid (ATRA) induces granulocytic maturation of WEHI-3B D+ leukemia cells and LiCl enhances this maturation, while WEHI-3B D- cells are non-responsive to ATRA. Transfection of SCL, expressed in D- but absent in D+ cells, into D+ cells, caused resistance to ATRA, while transfection of GATA-1 into D+ cells produced resistance to the combination of ATRA and LiCl. SCL expression in D+ cells did not induce the expression of c-Kit, a putative target gene for SCL. LiCl, known to inhibit some kinases by displacing Mg2+, did not affect tyrosine kinase activity of the cytoplasmic domain of c-Kit.

Oncoprotein EWS-FLI1 activity is enhanced by RNA helicase A.

RNA helicase A (RHA), a member of the DEXH box helicase family of proteins, is an integral component of protein complexes that regulate transcription and splicing. The EWS-FLI1 oncoprotein is expressed as a result of the chromosomal translocation t(11;22) that occurs in patients with the Ewing's sarcoma family of tumors (ESFT). Using phage display library screening, we identified an EWS-FLI1 binding peptide containing homology to RHA. ESFT cell lines and patient tumors highly expressed RHA. GST pull-down and ELISA assays showed that EWS-FLI1 specifically bound RHA fragment amino acids 630 to 1020, which contains the peptide region discovered by phage display. Endogenous RHA was identified in a protein complex with EWS-FLI1 in ESFT cell lines. Chromatin immunoprecipitation experiments showed both EWS-FLI1 and RHA bound to EWS-FLI1 target gene promoters. RHA stimulated the transcriptional activity of EWS-FLI1 regulated promoters, including Id2, in ESFT cells. In addition, RHA expression in mouse embryonic fibroblast cells stably transfected with EWS-FLI1 enhanced the anchorage-independent phenotype above that with EWS-FLI1 alone. These results suggest that RHA interacts with EWS-FLI1 as a transcriptional cofactor to enhance its function.

Analysis of the relationship between Scl transcription factor complex protein expression patterns and the effects of LiCl on ATRA-induced differentiation in blast cells from patients with acute myeloid leukemia.

Exogenous expression of the transcription factor Scl (Tal1) in WEHI-3B D+ myelomonocytic leukemia cells interferes with their capacity to respond to all-trans retinoic acid (ATRA) induced differentiation; combination of ATRA with LiCl, however, circumvents the inhibition of differentiation produced by Scl. To gain information on the possible involvement of this transcription factor in the non-responsiveness of acute myelocytic leukemia (AML) patients to ATRA, we compared the endogenous expression levels of Scl and its transcription complex partners [i.e., Rbtn1 (LMO1), Rbtn2 (LMO2), Ldb1, and GATA family proteins] in leukemic blast cells from patients with AML and acute promyelocytic leukemia (APL), and determined the effects of lithium chloride alone or in combination with ATRA on the capacity of blast cells to differentiate during short-term ex vivo culture. Levels of Scl, Rbtn2, GATA1, and Ldb1 expression were comparable in AML and APL blasts, while the levels of expression of Rbtn1, GATA2, and GATA3 were absent or markedly lower in APL cells. Differentiation markers (cell surface myeloid antigens CD11b, CD15, CD14, and CD33) were also analyzed in blast cells. ATRA produced changes in at least one surface antigen differentiation marker in 89% of patient blasts, while LiCl caused such changes in 72% of the leukemic cells of patients. The combination of LiCl and ATRA induced the differentiation of leukemic blasts from 94% of patients. Although the expression of the transcription factors did not act as individual predictors of responsiveness or non-responsiveness to the inducers of differentiation, ATRA or ATRA plus LiCl, the addition of LiCl to ATRA increased the differentiation response over that of ATRA alone in a number of leukemic samples. These findings suggest that the combination of LiCl and ATRA may produce some clinical benefit in the treatment of the myeloid leukemias.

Combination of all-trans retinoic acid and lithium chloride surmounts a retinoid differentiation block induced by expression of Scl and Rbtn2 transcription factors in myeloid leukemia cells.

We have previously shown that forced expression of the transcription factor Scl in WEHI-3B D(+) cells prevents ATRA-induced cell differentiation. We now find that the overexpression of Rbtn2 also interferes with induction of differentiation by ATRA. Addition of LiCl to ATRA treatment restored the capacity of both Scl- and Rbtn2-expressing cells to respond to the retinoid in a synergistic manner. Similar results were obtained with Scl-transfected HL60 cells where its expression diminished responsiveness to ATRA. These findings suggest that if Scl and/or Rbtn2 are involved in the non-responsiveness of AML patients to ATRA-induced differentiation, addition of LiCl may reverse insensitivity.

Lithium chloride inactivates the 20S proteasome from WEHI-3B D+ leukemia cells.

LiCl interacts synergistically with all-trans-retinoic acid, promoting the terminal differentiation of WEHI-3B D(+) cells, a phenomenon partially due to the ability of the monovalent lithium cation to inhibit the proteasome-dependent degradation of retinoic acid receptor alpha protein. In this report, the 20S proteasome was purified from WEHI-3B D(+) cells and the effects of LiCl on chymotrypsin-like (Chtl) activity and peptidyl-glutamyl peptide hydrolyzing (PGPH) activity were determined. LiCl functions to inactivate both proteasomal activities in a time-dependent manner, without affecting non-proteasomal proteases. The half-lives for inactivation of Chtl and PGPH hydrolyzing activities were approximately 23 and 36min, respectively, at 10mM LiCl. Both SDS and peptide substrate increased the rate of inactivation. Partial enzymatic activity was recovered after dialysis in the absence of SDS, indicating that the off-rate for lithium was extremely slow. The findings suggest that the inactivation of Chtl and PGPH activities by LiCl occurs through a proteasomal conformational change.

Ewing sarcoma family of tumors express adenovirus receptors and are susceptible to adenovirus-mediated oncolysis.

PURPOSE: Attenuated viruses derived from adenoviruses (Ad) that kill tumor cells (oncolysis) are currently in clinical trials for selected cancers. Some cancers have proven resistant to Ad infection due to low expression of viral receptors. The authors sought to determine whether members of the Ewing sarcoma family of tumors (ESFTs) express Ad receptors and are sensitive to Ad-mediated oncolysis. METHODS: Using flow cytometry, the authors tested a panel of cell lines derived from ESFTs for expression of both the Ad receptor, coxsackie-adenovirus receptor (CAR), and the cellular mediator of Ad uptake, alpha(v)-integrins, as well as for Ad-mediated gene transduction. Cell survival assays were used to assess the sensitivity to Ad-mediated oncolysis. Immunohistochemistry was used to assess CAR expression in primary tumors. mRNA levels of CAR in cell lines and tumor samples were also queried from a cDNA expression database. RESULTS: The ESFT cell lines expressed CAR and alpha(v)-integrins, showed high levels of gene transduction, and were highly sensitive to viral oncolysis. Primary tumor samples were positive for CAR expression by immunohistochemistry. Microarray analysis confirmed CAR expression in ESFT cell lines and tumors. CONCLUSIONS: Ewing sarcoma cells express the Ad receptors and are sensitive to Ad oncolysis. Treatment of Ewing sarcoma using conditionally replicative adenoviruses should be explored.