Matthew Ming Kong Shing

Transcriptional repression of the RUNX3/AML2 gene by the t(8;21) and inv(16) fusion proteins in acute myeloid leukemia

RUNX3/AML2 is a Runt domain transcription factor like RUNX1/AML1 and RUNX2/AML3. Regulated by 2 promoters P1 and P2, RUNX3 is frequently inactivated by P2 methylation in solid tumors. Growing evidence has suggested a role of this transcription factor in hematopoiesis. However, genetic alterations have not been reported in blood cancers. In this study on 73 acute myeloid leukemia (AML) patients (44 children and 29 adults), we first showed that high RUNX3 expression among childhood AML was associated with a shortened event-free survival, and RUNX3 was significantly underexpressed in the prognostically favorable subgroup of AML with the t(8;21) and inv(16) translocations. We further demonstrated that this RUNX3 repression was mediated not by P2 methylation, but RUNX1-ETO and CBFbeta-MYH11, the fusion products of t(8;21) and inv(16), via a novel transcriptional mechanism that acts directly or indirectly in collaboration with RUNX1, on 2 conserved RUNX binding sites in the P1 promoter. In in vitro studies, ectopically expressed RUNX1-ETO and CBFbeta-MYH11 also inhibited endogenous RUNX3 expression. Taken together, RUNX3 was the first transcriptional target found to be commonly repressed by the t(8;21) and inv(16) fusion proteins and might have an important role in core-binding factor AML.

Detection of micrometastasis of neuroblastoma to bone marrow and tumor dissemination to hematopoietic autografts using flow cytometry and reverse transcriptase-polymerase chain reaction.

The identification of neuroblastoma metastases to bone marrow (BM) is requisite in staging disease for risk‐adopted therapy. However, micrometastases were not elucidated fully.

Elevated Serum Interleukin-15 Level in Acute Graft-versus-host Disease After Hematopoietic Cell Transplantation

Objective To correlate serum cytokine levels and the development of acute graft-versus-host disease (GVHD), the authors conducted a prospective study on serial measurements of interferon (IFN)-&ggr; and interleukin (IL)-10, IL-12 and IL-15. Methods The cytokines were measured in 27 subjects by enzyme-linked immunosorbent assay serially for the first 2 months after hematopoietic cell transplantation. Results Nineteen subjects with acute GVHD had significantly higher mean peak serum levels of IFN-&ggr; and IL-15 than the baseline levels at the start of conditioning. The peak level occurred soon after stem cell infusion and returned to the pretransplantation state in the second month. In contrast, there was lesser difference between the mean peak serum levels of IFN-&ggr;, IL-10, and IL-15 and the baseline level in the eight subjects without GVHD. The peak serum level for IL-15 was, in addition, significantly higher among GVHD subjects than those without GVHD in the first month posttransplantation. However, the level of IL-15 showed no correlation with the severity of GVHD. Conclusions These changes point to a possible role of systemic cytokine secretion in the development of acute GVHD. Elevated levels of IL-15 early in the posttransplant period could be a helpful laboratory predictor of acute GVHD.

Growth and endocrine function following bone marrow transplantation for thalassemia major.

Thalassemia major (TM) patients frequently suffer from growth delay and endocrine dysfunction. Thirty-two TM patients who had survived more than 2 years after bone marrow transplantation (BMT) were recruited for growth and endocrine study. Patients were followed up annually for growth, and the height was expressed as height standard deviation score (HtSDS). The HtSDS at baseline was –1.51 and was more reduced in patients older than 7 years (−1.99) as compared with those younger patients (–0.79) (=. 027). The HtSDS gradually improved after BMT and increased by 0.59 (CI 0.16–1.01) at 5 years after BMT. Forty percent of patients were below 2 SD at time of BMT but this decreased to 15% at the latest assessment. The hormonal profiles of gonadotrophins, sex hormones, and thyroid function were assayed regularly after BMT. With a median follow-up of 67 months, ovarian failure was universal among the 10 girls evaluable for puberty and all required hormonal replacement. Eight of 10 boys had spontaneous puberty but 3 of them had gonadal impairment. One patient developed diabetes mellitus and one had growth hormone deficiency after BMT. In conclusion, improvement of growth after BMT in TM was common. Gonadal failure is universal in girls, and boys were less affected.

Human neonatal blood: stem cell content, kinetics of CD34+ cell decline and ex vivo expansion capacity

Haemopoietic stem cells are present in fetal blood but their levels decline rapidly in the peripheral circulation of the infant after birth. We previously reported a case of stem cell transplant in a β‐thalassaemia boy using a combination of the cord blood (CB) and neonatal blood (NB) of his sister. This transplant resulted in a successful engraftment. To investigate the possibility of using NB to supplement CB for related transplants, we further characterized stem and progenitor cells and lymphocyte subsets in 20 NB samples, comparing the findings with those in 20 CB samples. Our data showed that NB contained substantial levels of CD34+ cells, CD34+CD38− cells, colony‐forming units‐granulocyte macrophage (CFU‐GM), colony forming units‐erythroid (CFU‐E), burst forming units‐erythroid (BFU‐E) and long‐ term culture initiating cells (LTCIC). NB was similar to CB in the levels of T lymphocytes, but the amounts of B lymphocytes and natural killer cells were higher in CB (P = 0.033, P = 0.001, respectively). The kinetics of CD34+ cells in NB was investigated in serial blood samples obtained from 10 full‐term infants at 2, 4, 6, 8, 24 and 48 h after birth. CD34+ cells decreased rapidly after birth, declining to only 30% of the 2 h level at 48 h (P < 0.012). The rate of decline was greatest in the first 4 h of life. NB from four infants was expanded by culturing the blood samples in the presence of thrombopoietin (Tpo), interleukin 1β (IL‐1β), IL‐3, IL‐6, flt‐3 ligand and stem cell factor (SCF) for 7 d. This resulted in the increase of CD34+ cells, CFU‐GM and CFU‐MK by 271 ± 179, 556 ± 385 and 113 ± 75 fold respectively. Three of the five samples expanded for 7 d contained LTCIC. These findings suggest that NB might be a supplementary or alternative source of stem cells to CB for transplant. The ethics and practicality of this approach deserve further exploration.

Intracranial Germ Cell Tumors in Children With and Without Down Syndrome

PURPOSE Two Chinese children with Down syndrome affected by intracranial germ cell tumors are described. Because they represent two of eight affected patients in the current series from 1990 to 1996, it is postulated that such occurrence may be more than a coincidental event. PATIENTS AND METHODS Two children with Down syndrome developed germ cell tumors in atypical intracranial sites that affected basal ganglion and cerebellum. The pathology showed germinoma and yolk sac tumor, respectively. These were treated by radical surgical resection and chemotherapy with cisplatin, etoposide, and bleomycin, but without radiotherapy. RESULTS One patient survived 3 years without radiologic evidence of tumor. The other died from infective complications caused by severe myelosuppression after chemotherapy. CONCLUSIONS Subtle neurologic manifestations in developmentally handicapped patients with intracranial space-occupying lesions could result in delayed diagnosis. Children with Down syndrome suffering from brain tumors may have a higher chance for germ cell tumors. Assay for alpha-fetoprotein and beta-human chorionic gonadotrophin could hasten diagnosis in some cases. This observation and review of literature suggest an increased risk of developing intracranial germ cell tumors in subjects with Down syndrome.

Treatment of hemoglobin Bart's hydrops with bone marrow transplantation☆☆☆★★★

A 21-month-old girl with hemoglobin Barts hydrops received bone marrow transplantation (BMT) from a matched sibling. No major BMT-related complications developed. Hemoglobin levels remained greater than 10 gm/dl for 20 months without blood transfusion support despite the presence of residual host hemopoietic cells from 2 months after BMT. We suggest consideration of this therapeutic option for surviving patients.

Allogeneic peripheral blood stem cell transplant in children

Allogeneic peripheral blood stem cell (PBSC) transplant has recently been introduced for the treatment of hematological malignancies. As the data were limited mainly to adult patients, this study aimed to assess the feasibility and safety of this procedure in pediatric patients and donors. Eleven children aged 2-16 years received allogeneic PBSC transplant for acute lymphoblastic leukemia (n = 4), acute myeloid leukemia (n = 1), myelodysplastic syndrome (n = 1), severe aplastic anemia (n = 3), and thalassemia (n = 2). Nine donors were human leukocyte antigen (HLA)-identical siblings and the other two were one antigen mismatched family members. Eight donors were younger than 18 years old (10 months to 17 years). Donors were primed with granulocyte colony-stimulating factor (G-CSF) at 10-16 micrograms/kg for 4-5 days. Aphereses were performed on 1 or 2 consecutive days, and the patients received a mean of 14.4 x 10(8)/kg nucleated cells, 6.9 x 10(6)/kg CD34 cells, and 6.9 x 10(8)/kg T cells. All patients achieved neutrophil counts of > 0.5 x 10(9)/l at a median of 16 days. Nine patients achieved platelet counts of > 20 x 10(9)/l at a median of 13 days. Grade II acute graft vs. host disease (GVHD) occurred in only one patient. Chronic GVHD was not observed in the seven patients with follow-up of more than 3 months. Eight patients remained in continuous complete remission after transplant ranged from 2 to 26 months. Allogeneic PBSC transplant appears safe in pediatric patients and donors, and it seems not to be associated with increase of acute GVHD or chronic GVHD.

Secreted-frizzled related protein 1 is a transcriptional repression target of the t(8;21) fusion protein in acute myeloid leukemia

Secreted-frizzled related proteins (SFRPs) are modulators of the Wnt signaling pathway that is closely involved in normal and malignant hematopoiesis. Epigenetic deregulation of Wnt modulators leading to aberrant signaling has been reported in adult patients with acute myeloid leukemia (AML), but its occurrence in childhood patients with AML and the role of individual modulators are unclear. In this study, we examined SFRP1, SFRP2, SFRP4, and SFRP5 promoter methylation in 83 patients with AML (59 children and 24 adults) and found preferential SFRP1 methylation and mRNA down-regulation in the prognostically favorable subgroup of AML with t(8;21) translocation. Among the 4 genes, SFRP1 methylation independently predicted prolonged event-free and relapse-free survivals in childhood patients with nonacute promyelocytic leukemia with nonadverse cytogenetics. Mechanistically, we further demonstrated that RUNX1-ETO, the t(8;21) fusion product, specifically bound the SFRP1 promoter and repressed its transcription via a consensus RUNX binding site. In t(8;21)-leukemia cells, SFRP1 selectively inhibited canonical Wnt signaling and cellular proliferation that were associated with concomitant down-regulation of Wnt/β-catenin target genes, including CCND1 and MYC. Taken together, we identified SFRP1 as a transcriptional repression target of the t(8;21) fusion protein and demonstrated a novel mechanism of Wnt activation in a specific subtype of AML.

Validation of the Chinese version of the Pediatric Quality of Life Inventory (PedsQL) Cancer Module.

OBJECTIVE The psychometric properties of the Chinese version of the Pediatric Quality of Life Inventory (PedsQL) Cancer Module were investigated. METHODS This instrument and the Generic Core Scales were administered to 359 pediatric patients with cancer (5-18 years) and 413 parents of such patients (2-18 years old). RESULTS Seven and eight factors were, respectively, identified for the patient and parent versions. The Cronbachs alpha coefficients were respectively .89 and .92 for the total scale, and respectively .75-.90 and .76-.93 for the subscales of the patient and parent versions. Test-retest reliability coefficients exceeded .60 for most cases. The total/subscale scores of the Cancer Module significantly correlated with those of the Generic Core Scales. Some of the subscales could distinguish between on-treatment and off-treatment patients. CONCLUSIONS The psychometric properties of the patient and parent versions of the Chinese PedsQL Cancer Module were found acceptable.