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ADAMTSL5 and CDH11: putative epigenetic markers for therapeutic resistance in acute lymphoblastic leukemia

Abdullah M, Choo CW, Alias H, Abdul Rahman EJ, Mohd Ibrahim H, Jamal R, et al.

Hematology, 2017 Aug;22(7):386-391.
PMID: 28292214 DOI: 10.1080/10245332.2017.1299417

BACKGROUND AND OBJECTIVES: DNA hypermethylation has been linked to poor treatment outcome in childhood acute lymphoblastic leukemia (ALL). Genes differentially methylated in the chemoresponsive pre-B-ALL compared to chemoresistant pre-B-ALL cases provide potential prognostic markers.
METHODS: DNA methylation profiles of five B-ALL childhood patients who achieved morphological complete remission (chemoresponsive) and five B-ALL patients who did not (chemoresistant) after induction treatments as well as four normal controls were compared on 27 000 CpG sites microarray chips. Subsequently, methylation-specific polymerase chain reaction (MSP) on selected hypermethylated genes was conducted on an additional 37 chemoresponsive and 9 chemoresistant B-ALL samples and 2 normal controls.
RESULTS: Both methods were found to be highly correlated. Unsupervised principal component analysis showed that the chemotherapy-responsive and -resistant B-ALL patients could be segregated from one another. Selection of segregated genes at high stringency identified two potential genes (CDH11 and ADAMTSL5). MSP analysis on the larger cohort of samples (42 chemoresponsive, 14 chemoresistant B-ALL samples and 6 normal controls) revealed significantly higher rates of hypermethylation in chemoresistant samples for ADAMTSL5 (93 vs. 38%; p = 0.0001) and CDH11 (79% vs. 40%, p
Whole-Exome Sequencing of ETV6/RUNX1 in Four Childhood Acute Lymphoblastic Leukaemia Cases

Zakaria Z, Othman N, Ismail A, Kamaluddin NR, Esa E, Abdul Rahman EJ, et al.

Asian Pac J Cancer Prev, 2017 04 01;18(4):1169-1175.
PMID: 28548470

Background: ETV6/RUNX1 gene fusion is the most frequently seen chromosomal abnormality in childhood acute
lymphobastic leukamia (ALL). However, additional genetic changes are known to be required for the development of
this type of leukaemia. Therefore, we here aimed to assess the somatic mutational profile of four ALL cases carrying the
ETV6/RUNX1 fusion gene using whole-exome sequencing. Methods: DNA was isolated from bone marrow samples
using a QIAmp DNA Blood Mini kit and subsequently sequenced using the Illumina MiSeq system. Results: We
identified 12,960 to17,601 mutations in each sample, with a total of 16,466 somatic mutations in total. Some 15,533
variants were single nucleotide polymorphisms (SNPs), 129 were substitutions, 415 were insertions and 389 were
deletions. When taking into account the coding region and protein impact, 1,875 variants were synonymous and 1,956
were non-synonymous SNPs. Among non-synonymous SNPs, 1,862 were missense, 13 nonsense, 35 frameshifts, 11
nonstop, 3 misstart, 15 splices disrupt and 17 in-frame indels. A total of 86 variants were located in leukaemia-related
genes of which 32 variants were located in the coding regions of GLI2, SP140, GATA2, SMAD5, KMT2C, CDH17,
CDX2, FLT3, PML and MOV10L1. Conclusions: Detection and identification of secondary genetic alterations are
important in identifying new therapeutic targets and developing rationally designed treatment regimens with less
toxicity in ALL patients.
Childhood adrenocortical carcinoma as a sentinel cancer for detecting families with germline TP53 mutations

Choong SS, Latiff ZA, Mohamed M, Lim LL, Chen KS, Vengidasan L, et al.

Clin Genet, 2012 Dec;82(6):564-8.
PMID: 22233476 DOI: 10.1111/j.1399-0004.2012.01841.x

Li-Fraumeni syndrome (LFS) is a highly penetrant, autosomal dominant disorder where affected individuals carry a 50% risk of developing cancer before 30 years of age. It is most commonly associated with mutations in the tumour suppressor gene, TP53. Adrenocortical carcinoma (ACC) is a very rare paediatric cancer, and up to 80% of affected children are found to carry germline TP53 mutations. Hence, we propose using childhood ACC incidence as selection criteria for referral for TP53 mutation testing, independent of familial cancer history. Under the auspices of the Malaysian Society of Paediatric Haematology-Oncology, four eligible children diagnosed with ACC over a 30-month study period were referred for mutation testing. Three had a germline TP53 mutation. Subsequent TP53 testing in relatives showed two inherited mutations and one de novo mutation. These findings strongly support paediatric ACC as a useful sentinel cancer for initiating a germline TP53/LFS detection programme, particularly in countries where the lack of structured oncogenetic practice precludes the identification of families with LFS features.
Fulltext Chromosomal Aberrations in ETV6/RUNX1-positive Childhood Acute Lymphoblastic Leukemia using 244K Oligonucleotide Array Comparative Genomic Hybridization

Zakaria Z, Ahid MF, Ismail A, Keoh TS, Nor NM, Kamaluddin NR, et al.

Mol Cytogenet, 2012;5(1):41.
PMID: 23151340 DOI: 10.1186/1755-8166-5-41
Heterogeneous t(4;11) fusion transcripts in two infants with acute lymphoblastic leukemia

Gill HK, Ten SK, Dhaliwal JS, Moore S, Hassan R, Karim FA, et al.

Malays J Pathol, 2004 Dec;26(2):105-10.
PMID: 16329562

An RT-PCR assay detected the t(4;11) translocation in two infants with acute lymphoblastic leukemia (ALL). Case P76 was a 10-month-old, female infant, who presented with a WBC of 137.4 x 10(9)/l and a pre-pre-B ALL immunophenotype. Case P120 was a 6-month-old female infant, with a WBC > 615 x 10(9)/l and a pre-pre-B ALL immunophenotype. RT-PCR of cDNA from both these cases generated a 656 bp and a 542 bp respectively, which sequencing confirmed as t(4;11) fusion transcripts. The primers and conditions selected for this assay are compatible with a one-step multiplex PCR for the main translocations in childhood ALL.
TEL-AML1 frequency in multi-ethnic Malaysian pediatric acute lymphoblastic leukemia

Gill HK, Keoh TS, Dhaliwal JS, Moore S, Kim TS, Hassan R, et al.

Cancer Genet. Cytogenet., 2005 Jan 15;156(2):129-33.
PMID: 15642392

Eighty-eight multi-ethnic Malaysian pediatric acute lymphoblastic leukemia (ALL) patients were screened for the TEL-AML1 rearrangement by reverse transcription-polymerase chain reaction (RT-PCR). Fluorescence in situ hybridization (FISH) was used as an independent screen for 30 cases and to confirm RT-PCR positive cases. Seventeen patients, or 19%, were found to be t(12;21) positive. Ethnically the group comprised 12 Malays, 4 Chinese, and 1 Indian. All patients, including 1 with an unusual blast cell morphology who suffered an early relapse and death, were characteristic TEL-AML1 cases in cell count, age, ALL subset classification, and fusion transcript expressed. This study shows that in Malaysia, TEL-AML1 is found in the same distinct ALL subset and at a similar frequency as in other diverse childhood ALL cohorts.