Influence of bcr-3 PML-RARα transcript on outcome in Acute Promyelocytic Leukemia patients of Kashmir treated with all-trans retinoic acid and/or arsenic tri-oxide.

AIMS: Distinct types of PML-RARα hybrid transcripts viz bcr-1, bcr-2 and bcr-3 result from translocation between chromosomes 15 and 17 t(15;17) in Acute Promyelocytic Leukemia patients. We aimed to determine the frequencies of the PML-RARα transcripts and FLT3-ITD mutations in APL patients to evaluate their prognostic implications and also to analyze their impact on disease outcome. MAIN METHOD: RT-PCR and Rq-PCR were adopted for transcript typing and quantitation of PML-RARα transcripts while FLT3-ITD was detected by PCR in APL patients. KEY FINDINGS: PML-RARα bcr-1, bcr-2 and bcr-3 transcripts were found in 26, 3 and 16 cases respectively. 64.4% patients achieved complete remission, 22.2% expired early wherein majority of the cases expressed bcr-3 transcript (p = 0.03). 50% relapse rate was observed in patients with bcr-3 transcripts. Multivariate analysis showed expression of bcr-3 transcript associated with early death (p = 0.027) and increased relapse risk (P = 0.046). Patients expressing bcr-3 hybrid transcript showed lowest OS of 28.0 months (±â€¯5.26) (p = 0.027). FLT3-ITD mutation was detected in 5 (11.1%) patients and presence of these mutations was not associated either with PML-RARα transcripts or with disease outcome. SIGNIFICANCE: bcr-3 transcript has a more lethal outcome and is also associated with frequent relapse risk in APL patients of our region.

p15Ink4b Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients.

PURPOSE: The p15Ink4b gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). MATERIALS AND METHODS: p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysiswas carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. CONCLUSION: Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.

p15(Ink4b) Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The p15(Ink4b) gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). MATERIALS AND METHODS: p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysis was carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. CONCLUSION: Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.

p15(Ink4b) Loss of Expression by Promoter Hypermethylation Adds to Leukemogenesis and Confers a Poor Prognosis in Acute Promyelocytic Leukemia Patients / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The p15(Ink4b) gene exerts its influence as an inhibitor of cyclin-dependent kinases and is frequently associated with hematological malignancies. Inactivation of this gene through DNA methylation has been found to be the most prevalent epigenetic alteration reported, with a high frequency in all French-American-British subtypes of acute myeloid leukemias, including acute promyelocytic leukemia (APL). In this study,we investigated the prognostic significance of p15 gene promoter hypermethylation and its expression in APL patients of Kashmir (North India). MATERIALS AND METHODS: p15 gene promoter hypermethylation was conducted by methylation-specific polymerase chain reaction, while its subsequent expression analysis was carried out by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Of the 37 patients, 16 (43.2%) were found to have methylated p15 genes. Of these 16 cases, seven (43.8%) were methylated partially and nine (56.2%) were found to have complete methylation. Moreover, nine of the 37 patients (24.3%) who presented with leukocytosis at their baseline had complete p15 gene methylation as well (p < 0.05). Semiquantitative RT-PCR showed a complete loss of p15 expression in nine patients with complete methylation coupled with leukocytosis (p=0.031), while seven patients with partial methylation showed decreased p15 expression. Six patients relapsed during the maintenance phase of treatment and were found to have a completely methylated p15 gene and no p15 mRNA. CONCLUSION: Complete methylation and loss of p15 gene expression causes susceptibility to relapse and decreased survival in APL patients. Thus, p15 promoter hypermethylation is a prospective prognostic indicator and a reliable clinical aid in assessment of patients with APL.