The role of the mineralocorticoid receptor in steroidinduced cytotoxicity in pediatric acute lymphoblastic leukemia

Not available.

Comprehensive molecular and clinical characterization of NUP98 fusions in pediatric acute myeloid leukemia

NUP98 fusions c omprise a family o f rare r ecurrent a lterations i n A ML, associated w ith adverse outcomes. To define the underlying biology and clinical implications of this family of fusions, we performed comprehensive transcriptome, epigenome, and immunophenotypic profiling of 2,235 children and young adults with AML and identified 160 NUP98 rearrangements (7.2%), including 108 NUP98-NSD1 (4.8%), 32 NUP98-KDM5A (1.4%) and 20 NUP98-X cases (0.9%) with 13 different fusion partners. Fusion partners defined disease characteristics and biology; patients with NUP98-NSD1 or NUP98-KDM5A had distinct immunophenotypic, transcriptomic, and epigenomic profiles. Unlike the two most prevalent NUP98 fusions, NUP98-X variants are typically not cryptic. Furthermore, NUP98-X cases are associated with WT1 mutations, and have epigenomic profiles that resemble either NUP98- NSD1 or NUP98-KDM5A. Cooperating FLT3-ITD and WT1 mutations define NUP98-NSD1, and chromosome 13 aberrations are highly enriched in NUP98-KDM5A. Importantly, we demonstrate that NUP98 fusions portend dismal overall survival, with the noteworthy exception of patients bearing abnormal chr13.

Longitudinal development of cancer-related fatigue and physical activity in childhood cancer patients

PURPOSE

Cancer-related fatigue is one of the most distressing side effects of childhood cancer treatment. Physical activity can decrease fatigue and has positive effects on other health outcomes. Most research on physical activity pertains to adults, and the few studies that focus on children have limited follow-up time. This study evaluates cancer-related fatigue in children and its association with physical activity over a one-year time period.

METHODS

Sixty-eight children with cancer (7-18 years) were recruited during or within the first year after treatment. Physical activity (Actical activity monitor) and cancer-related fatigue (Pediatric Quality-of-Life Questionnaire Multidimensional Fatigue Scale (PedsQL-MFS), self- and parent- reports) were assessed at baseline, 4 months, and 12 months. PedsQL-MFS scores were compared with Dutch norms. Longitudinal association of cancer-related fatigue with physical activity was evaluated (No. NTR 1531).

RESULTS

Generally, PedsQL-MFS scores were worse than norms at baseline and 4 months, and recovered by 12 months except for the parent-proxy scores in adolescents. Younger children (≤12 years) self-reported comparable or better scores than norms. Physical activity generally improved over time, but patients mostly remained sedentary. During follow-up, increased physical activity was associated with less cancer-related fatigue.

CONCLUSION

Cancer-related fatigue in children improves over time, and increased physical activity is associated with less cancer-related fatigue. Given the sedentary lifestyle of this population, the positive effect of physical activity on cancer-related fatigue, and the many other health benefits of an active lifestyle, it is important to stimulate physical activity in childhood cancer patients and survivors.

Evaluation of gene expression signatures predictive of cytogenetic and molecular subtypes of pediatric acute myeloid leukemia

BACKGROUND

Pediatric acute myeloid leukemia is a heterogeneous disease characterized by non-random genetic aberrations related to outcome. The genetic subtype is currently detected by different diagnostic procedures which differ in success rate and/or specificity.

DESIGN AND METHODS

We examined the potential of gene expression profiles to classify pediatric acute myeloid leukemia. Gene expression microarray data of 237 children with acute myeloid leukemia were collected and a double-loop cross validation approach was used to generate a subtype-predictive gene expression profile in the discovery cohort (n=157) which was then tested for its true predictive value in the independent validation cohort (n=80). The classifier consisted of 75 probe sets, representing the top 15 discriminating probe sets for MLL-rearranged, t(8;21)(q22;q22), inv(16)(p13q22), t(15;17)(q21;q22) and t(7;12)(q36;p13)-positive acute myeloid leukemia.

RESULTS

These cytogenetic subtypes represent approximately 40% of cases of pediatric acute myeloid leukemia and were predicted with 92% and 99% accuracy in the discovery and independent validation cohort, respectively. However, for NPM1, CEBPA, MLL(-PTD), FLT3(-ITD), KIT, PTPN11 and N/K-RAS gene expression signatures had limited predictive value. This may be caused by a limited frequency of these mutations and by underlying cytogenetics. This latter is exemplified by the fact that different gene expression signatures were discovered for FLT3-ITD in patients with normal cytogenetics and in those with t(15;17)(q21;q22)-positive acute myeloid leukemia, which pointed to HOXB-upregulation being specific for FLT3-ITD(+) cytogenetically normal acute myeloid leukemia.

CONCLUSIONS

In conclusion, gene expression profiling correctly predicted the most prevalent cytogenetic subtypes of pediatric acute myeloid leukemia with high accuracy. In clinical practice, this gene expression signature may replace multiple diagnostic tests for approximately 40% of pediatric acute myeloid leukemia cases whereas only for the remaining cases (predicted as 'acute myeloid leukemia-other') are additional tests indicated. Moreover, the discriminative genes reveal new insights into the biology of acute myeloid leukemia subtypes that warrants follow-up as potential targets for new therapies.

ABCB1 gene polymorphisms are not associated with treatment outcome in elderly acute myeloid leukemia patients

OBJECTIVES

The classical multidrug resistance (MDR) gene MDR1 (ABCB1) encodes for the drug efflux pump P-glycoprotein (P-gp). P-gp expression is an adverse prognostic factor for treatment outcome in acute myeloid leukemia (AML) and is more frequently observed in older patients. Single-nucleotide polymorphisms of the ABCB1 gene, C1236T, G2677T, and C3435T, have been associated with altered drug metabolism and treatment outcome. We prospectively determined these single-nucleotide polymorphisms in AML blasts in a cohort of patients aged 60 years or older with AML and evaluated their relevance with regard to P-gp function and expression, ABCB1 messenger ribonucleic acid (mRNA) expression, and clinical outcome.

METHODS

We have analyzed purified bone marrow-derived leukemic blasts, obtained at diagnosis, in 150 patients who were treated within a multicenter, randomized, phase 3 trial of elderly patients with AML. The significance of the allelic ABCB1 variants of C1236T, G2677T, and C3435T was evaluated with respect to P-gp expression and function in leukemic blasts and ABCB1 mRNA expression levels, and these values were correlated with treatment outcome.

RESULTS

P-gp function and expression in leukemic blasts and ABCB1 mRNA levels in patients with AML did not vary significantly among any of the allelic variants of ABCB1. None of these allelic variations predicted a difference in complete response rate and survival endpoints.

CONCLUSIONS

In AML patients aged 60 years or older, allelic ABCB1 variations of C1236T, G2677T, or C3435T are not associated with altered P-gp function or with MDR1 expression at the transcriptional or translational level in leukemic blasts, and they do not significantly affect clinical prognosis.