RETRACTED: Lack of CpG island methylator phenotype defines a clinical subtype of T-cell acute lymphoblastic leukemia associated with good prognosis (Retracted article. See vol. 31, pg. 979, 2013)

Purpose To examine cancer genes undergoing epigenetic inactivation in a set of T-cell acute lymphoblastic leukemias (T-ALLs) to obtain the CpG island methylator phenotype (CIMP) in the disease and its possible correlation with clinical features and outcome of the patients. Patients and Methods Methylation-specific polymerase. chain reaction was used to analyze methylation of the ADAMTS-1, ADAMTS-5, APAF-1, ASPP-1, CDH1, CDH13, DAPK DIABLO, DKK-3, LATS-1, LATS-2, NES-1, p14, p15, p16, p57, p73, PARK-2, PTEN, sFRP1/2/4/5, SHP-1, SYK TMS-1, and WIF-1 genes in samples from 50 consecutive T-ALL patients (19 children and 31 adults). Results were compared with results obtained in 286 B-cell acute lymphoblastic leukemias (B-ALLs). Results A total of 88% of the T-ALL samples had at least one gene methylated. According to the number of methylated genes observed in each individual sample, 12 patients (24%) were included in the CIMP- group (zero to two methylated genes), and 38 patients (76%) were included in the CIMP+ group (> two methylated genes). Clinical features and remission rate did not differ significantly among both groups of patients. Estimated disease-free survival QFS) rate at 12 years and overall survival (OS) rate at 13 years were 100% and 91% for the CIMP- group and 20% and 17% for the CIMP+ group, respectively (P =.0006 and P =.003, respectively). Multivariate analysis demonstrated that methylation profile was an independent prognostic factor in predicting DFS (P =.05) and CIS (P =.02). A group of five genes (SYK-1, ASPP-1, sFRP-2, sFRP-5, and WIF-1) showed specificity for T-ALL compared with B-ALL. Conclusion Our results suggest that the methylation profile may be a potential new biomarker of risk prediction in T-ALL.