Aberrant DNA methylation is associated with a poor outcome in Juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML), an overlap of myelodysplastic/myeloproliferative neoplasm, is an intractable pediatric myeloid neoplasm. Epigenetic regulation of transcription, particularly by CpG methylation, plays an important role in tumor progression, mainly by repressing tumor-suppressor genes. To clarify the clinical importance of aberrant DNA methylation, we studied the hypermethylation status of 16 target genes in the genomes of 92 patients with JMML by bisulfite conversion and the pryosequencing technique. Among 16 candidate genes, BMP4, CALCA, CDKN2A, and RARB exhibited significant hypermethylation in 72% (67/92) of patients. Based on the number of hypermethylated genes, patients were stratified into three cohorts based on an aberrant methylation score (AMS) of 0, 1-2, or 3-4. In the AMS 0 cohort, the 5-year overall survival (OS) and transplantation-free survival (TFS) were good (69% and 76%, respectively). In the AMS 1-2 cohort, the 5-year OS was comparable to that in the AMS 0 cohort (68%), whereas TFS was poor (6%). In the AMS 3-4 cohort, 5-year OS and TFS were markedly low (8% and 0%, respectively). Epigenetic analysis provides helpful information for clinicians to select treatment strategies for patients with JMML. For patients with AMS 3-4 in whom hematopoietic stem cell transplantation does not improve the prognosis, alternative therapies, including DNA methyltransferase inhibitors and new molecular-targeting agents, should be established as treatment options

Allogeneic stem cell transplantation with reduced intensity conditioning for patients with adrenoleukodystrophy

Objective: The prognosis of adrenoleukodystrophy (ALD)with neurological involvement is generally dismal; however, allogeneic stem cell transplantation (SCT) is recognized as effective to stabilize or improve the clinical symptoms of ALD. Herein, we report the clinical outcomes of patients with ALD who consecutively underwent allogeneic stem cell transplantation with reduced intensity conditioning at our institution. Patients: Sixteen patients with ALD, who were symptomatic (n = 14) or presymptomatic (n = 2), received SCT from 2010 to 2016. The stem cell source was cord blood (n = 14), or bone marrow from a human leukocyte antigen identical sibling (n = 2). The conditioning regimen prior to transplantation was reduced intensity and consisted of fludarabine (125 mg/m2), melphalan (140 mg/m2) and low dose total body irradiation (TBI) of 4Gy (n = 15) or 3Gy (n = 1). Results: Primary engraftment was obtained in 11 patients, and 4 of the 5 patients who lost the primary graft received a second cord blood transplantation and were engrafted. Five years overall and event-free survival were 90.9% and 61.1% respectively, with a median of 45 months (range 16–91). Loes score stabilized or improved by 18 months after transplantation except for patients with internal capsule involvement. Conclusion: Allogeneic SCT with reduced intensity conditioning for patients with ALD was safely performed without major transplant-related complications even in symptomatic patients and neurological symptoms were stabilized after SCT in patients without internal capsule involvement. Keywords: Adrenoleukodystrophy, Allogeneic stem cell transplantation, Loes score, Very long chain fatty aci

Hypermethylation status and clinical outcome in patients with juvenile myelomonocytic leukemia (JMML).

<p>(A) Kaplan–Meier curves represent the probability of transplantation-free survival (TFS) in the 92 patients with JMML. TFS was defined as the probability of being alive and transplantation free. Both death and transplantation were considered events. The probability of 5-year TFS in the aberrant methylation score (AMS) 0 cohort (solid line) was significantly higher than that in the AMS 1–2 (long dashed line) and AMS 3–4 cohorts (dashed line), p < 0.001. (B) Kaplan–Meier curves represent the probability of overall survival (OS) in the 92 patients with JMML. Death was considered an event. The probability of OS in both the AMS 0 (solid line) and 1–2 cohorts (long dashed line) was significantly higher than that in the AMS 3–4 cohort (dashed line), p < 0.001.</p

Profile of genetic mutations and aberrant methylation.

<p>(A) Mutation status of RAS pathway genes and secondary genes (<i>SETBP1</i> and <i>JAK3</i>) identified as gene targets. Aberrant methylation scores (AMS) in a cohort of 92 patients with juvenile myelomonocytic leukemia are summarized. A rhombus denotes a patient with Noonan syndrome-associated myeloproliferative disorder. (B) Mutations in <i>SETBP1</i> and <i>JAK3</i> were associated with a higher AMS. The mean AMS of patients with <i>SETBP1</i> and/or <i>JAK3</i> mutations was higher than that of patients without secondary mutations (p = 0.03).</p

Summary of DNA methylation in candidate genes.

<p>(A) The dot plot represents the frequencies of methylated CpG sites for each candidate gene in the 92 patients with juvenile myelomonocytic leukemia. Aberrant hypermethylation was defined as >3 standard deviations above the mean methylation level of the healthy control population. The threshold values of each gene are shown as red broken lines. (B) Kaplan–Meier plots of the patient groups, defined by aberrant methylation of the indicated genes, are shown for <i>BMP4</i>, <i>CALCA</i>, <i>CDKN2A</i>, <i>CDKN2B</i>, <i>H19</i>, and <i>RARB</i>.</p

Patient characteristics.

<p>Patient characteristics.</p

Multivariate model for transplantation-free and overall survival.

<p>Multivariate model for transplantation-free and overall survival.</p