scholarly journals HRX involvement in de novo and secondary leukemias with diverse chromosome 11q23 abnormalities [see comments]

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3197-3203 ◽  
Author(s):  
SP Hunger ◽  
DC Tkachuk ◽  
MD Amylon ◽  
MP Link ◽  
AJ Carroll ◽  
...  

Abstract Chromosome band 11q23 is a site of recurrent translocations and interstitial deletions in human leukemias. Recent studies have shown that the 11q23 gene HRX is fused to heterologous genes from chromosomes 4 or 19 after t(4;11)(q21;q23) and t(11;19)(q23;p13) translocations to create fusion genes encoding proteins with structural features of chimeric transcription factors. In this report, we show structural alterations of HRX by conventional Southern blot analyses in 26 of 27 de novo leukemias with cytogenetically diverse 11q23 abnormalities. The sole case that lacked HRX rearrangements was a t(11;17)-acute myeloid leukemia with French-American-British M3-like morphology. We also analyzed 10 secondary leukemias that arose after therapy with topoisomerase II inhibitors and found HRX rearrangements in 7 of 7 with 11q23 translocations, and in 2 of 2 with unsuccessful karyotypes. In total, we observed HRX rearrangements in 35 leukemias involving at least nine distinct donor loci (1q32, 4q21, 6q27, 7p15, 9p21–24, 15q15, 16p13, and two 19p13 sites). All breakpoints localized to an 8-kb region that encompassed exons 5–11 of HRX, suggesting that fusion proteins containing similar portions of HRX may be consistently created in leukemias with 11q23 abnormalities. We conclude that alteration of HRX is a recurrent pathogenetic event in leukemias with 11q23 aberrations involving many potential partners in a variety of settings including acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia in blast crisis, and topoisomerase II inhibitor- induced secondary leukemias of both the myeloid and lymphoid lineages.

Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3197-3203 ◽  
Author(s):  
SP Hunger ◽  
DC Tkachuk ◽  
MD Amylon ◽  
MP Link ◽  
AJ Carroll ◽  
...  

Chromosome band 11q23 is a site of recurrent translocations and interstitial deletions in human leukemias. Recent studies have shown that the 11q23 gene HRX is fused to heterologous genes from chromosomes 4 or 19 after t(4;11)(q21;q23) and t(11;19)(q23;p13) translocations to create fusion genes encoding proteins with structural features of chimeric transcription factors. In this report, we show structural alterations of HRX by conventional Southern blot analyses in 26 of 27 de novo leukemias with cytogenetically diverse 11q23 abnormalities. The sole case that lacked HRX rearrangements was a t(11;17)-acute myeloid leukemia with French-American-British M3-like morphology. We also analyzed 10 secondary leukemias that arose after therapy with topoisomerase II inhibitors and found HRX rearrangements in 7 of 7 with 11q23 translocations, and in 2 of 2 with unsuccessful karyotypes. In total, we observed HRX rearrangements in 35 leukemias involving at least nine distinct donor loci (1q32, 4q21, 6q27, 7p15, 9p21–24, 15q15, 16p13, and two 19p13 sites). All breakpoints localized to an 8-kb region that encompassed exons 5–11 of HRX, suggesting that fusion proteins containing similar portions of HRX may be consistently created in leukemias with 11q23 abnormalities. We conclude that alteration of HRX is a recurrent pathogenetic event in leukemias with 11q23 aberrations involving many potential partners in a variety of settings including acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia in blast crisis, and topoisomerase II inhibitor- induced secondary leukemias of both the myeloid and lymphoid lineages.


Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3705-3711 ◽  
Author(s):  
HJ Super ◽  
NR McCabe ◽  
MJ Thirman ◽  
RA Larson ◽  
MM Le Beau ◽  
...  

Chromosome band 11q23 is frequently involved in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) de novo, as well as in myelodysplastic syndromes (MDS) and lymphoma. Five percent to 15% of patients treated with chemotherapy for a primary neoplasm develop therapy-related AML (t-AML) that may show rearrangements, usually translocations involving band 11q23 or, less often, 21q22. These leukemias develop after a relatively short latent period and often follow the use of drugs that inhibit the activity of DNA-topoisomerase II (topo II). We previously identified a gene, MLL (myeloid-lymphoid leukemia or mixed-lineage leukemia), at 11q23 that is involved in the de novo leukemias. We have studied 17 patients with t-MDS/t-AML, 12 of whom had cytogenetically detectable 11q23 rearrangements. Ten of the 12 t-AML patients had received topo II inhibitors and 9 of these, all with balanced translocations of 11q23, had MLL rearrangements on Southern blot analysis. None of the patients who had not received topo II inhibitors showed an MLL rearrangement. Of the 5 patients lacking 11q23 rearrangements, some of whom had monoblastic features, none had an MLL rearrangement, although 4 had received topo II inhibitors. Our study indicates that the MLL gene rearrangements are similar both in AML that develops de novo and in t-AML. The association of exposure to topo II- reactive chemotherapy with 11q23 rearrangements involving the MLL gene in t-AML suggests that topo II may play a role in the aberrant recombination events that occur in this region both in AML de novo and in t-AML.


Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4360-4362 ◽  
Author(s):  
Linda D. Pegram ◽  
Maureen D. Megonigal ◽  
Beverly J. Lange ◽  
Peter C. Nowell ◽  
Janet D. Rowley ◽  
...  

The partner gene of MLL was identified in a patient with treatment-related acute myeloid leukemia in which the karyotype suggested t(3;11)(q25;q23). Prior therapy included the DNA topoisomerase II inhibitors, teniposide and doxorubicin. Southern blot analysis indicated that the MLL gene was involved in the translocation. cDNA panhandle polymerase chain reaction (PCR) was used, which does not require partner gene-specific primers, to identify the chimeric transcript. Reverse-transcription of first-strand cDNAs with oligonucleotides containing known MLL sequence at the 5′ ends and random hexamers at the 3′ ends generated templates with an intra-strand loop for PCR. In-frame fusions of either MLLexon 7 or exon 8 with the GMPS (GUANOSINE 5′-MONOPHOSPHATE SYNTHETASE) gene from chromosome band 3q24 were detected. The fusion transcript was alternatively spliced. Guanosine monophosphate synthetase is essential for de novo purine synthesis. GMPS is the first partner gene ofMLL on chromosome 3q and the first gene of this type in leukemia-associated translocations.


Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 1912-1922 ◽  
Author(s):  
PL Broeker ◽  
HG Super ◽  
MJ Thirman ◽  
H Pomykala ◽  
Y Yonebayashi ◽  
...  

Abstract A major unresolved question for 11q23 translocations involving MLL is the chromosomal mechanism(s) leading to these translocations. We have mapped breakpoints within the 8.3-kb BamHI breakpoint cluster region in 31 patients with acute lymphoblastic leukemia and acute myeloid leukemia (AML) de novo and in 8 t-AML patients. In 23 of 31 leukemia de novo patients, MLL breakpoints mapped to the centromeric half (4.57 kb) of the breakpoint cluster region, whereas those in eight de novo patients mapped to the telomeric half (3.87 kb). In contrast, only two t-AML breakpoints mapped in the centromeric half, whereas six mapped in the telomeric half. The difference in distribution of the leukemia de novo breakpoints is statistically significant (P = .02). A similar difference in distribution of breakpoints between de novo patients and t-AML patients has been reported by others. We identified a low- or weak-affinity scaffold attachment region (SAR) mapping just centromeric to the breakpoint cluster region, and a high-affinity SAR mapping within the telomeric half of the breakpoint cluster region. Using high stringency criteria to define in vitro vertebrate topoisomerase II (topo II) consensus sites, one topo II site mapped adjacent to the telomeric SAR, whereas six mapped within the SAR. Therefore, 74% of leukemia de novo and 25% of t-AML breakpoints map to the centromeric half of the breakpoint cluster region map between the two SARs; in contrast, 26% of the leukemia de novo and 75% of the t-AML patient breakpoints map to the telomeric half of the breakpoint cluster region that contains both the telomeric SAR and the topo II sites. Thus, the chromatin structure of the MLL breakpoint cluster region may be important in determining the distribution of the breakpoints. The data suggest that the mechanism(s) leading to translocations may differ in leukemia de novo and in t-AML.


Blood ◽  
1996 ◽  
Vol 87 (5) ◽  
pp. 1912-1922 ◽  
Author(s):  
PL Broeker ◽  
HG Super ◽  
MJ Thirman ◽  
H Pomykala ◽  
Y Yonebayashi ◽  
...  

A major unresolved question for 11q23 translocations involving MLL is the chromosomal mechanism(s) leading to these translocations. We have mapped breakpoints within the 8.3-kb BamHI breakpoint cluster region in 31 patients with acute lymphoblastic leukemia and acute myeloid leukemia (AML) de novo and in 8 t-AML patients. In 23 of 31 leukemia de novo patients, MLL breakpoints mapped to the centromeric half (4.57 kb) of the breakpoint cluster region, whereas those in eight de novo patients mapped to the telomeric half (3.87 kb). In contrast, only two t-AML breakpoints mapped in the centromeric half, whereas six mapped in the telomeric half. The difference in distribution of the leukemia de novo breakpoints is statistically significant (P = .02). A similar difference in distribution of breakpoints between de novo patients and t-AML patients has been reported by others. We identified a low- or weak-affinity scaffold attachment region (SAR) mapping just centromeric to the breakpoint cluster region, and a high-affinity SAR mapping within the telomeric half of the breakpoint cluster region. Using high stringency criteria to define in vitro vertebrate topoisomerase II (topo II) consensus sites, one topo II site mapped adjacent to the telomeric SAR, whereas six mapped within the SAR. Therefore, 74% of leukemia de novo and 25% of t-AML breakpoints map to the centromeric half of the breakpoint cluster region map between the two SARs; in contrast, 26% of the leukemia de novo and 75% of the t-AML patient breakpoints map to the telomeric half of the breakpoint cluster region that contains both the telomeric SAR and the topo II sites. Thus, the chromatin structure of the MLL breakpoint cluster region may be important in determining the distribution of the breakpoints. The data suggest that the mechanism(s) leading to translocations may differ in leukemia de novo and in t-AML.


Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4360-4362 ◽  
Author(s):  
Linda D. Pegram ◽  
Maureen D. Megonigal ◽  
Beverly J. Lange ◽  
Peter C. Nowell ◽  
Janet D. Rowley ◽  
...  

Abstract The partner gene of MLL was identified in a patient with treatment-related acute myeloid leukemia in which the karyotype suggested t(3;11)(q25;q23). Prior therapy included the DNA topoisomerase II inhibitors, teniposide and doxorubicin. Southern blot analysis indicated that the MLL gene was involved in the translocation. cDNA panhandle polymerase chain reaction (PCR) was used, which does not require partner gene-specific primers, to identify the chimeric transcript. Reverse-transcription of first-strand cDNAs with oligonucleotides containing known MLL sequence at the 5′ ends and random hexamers at the 3′ ends generated templates with an intra-strand loop for PCR. In-frame fusions of either MLLexon 7 or exon 8 with the GMPS (GUANOSINE 5′-MONOPHOSPHATE SYNTHETASE) gene from chromosome band 3q24 were detected. The fusion transcript was alternatively spliced. Guanosine monophosphate synthetase is essential for de novo purine synthesis. GMPS is the first partner gene ofMLL on chromosome 3q and the first gene of this type in leukemia-associated translocations.


Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3705-3711 ◽  
Author(s):  
HJ Super ◽  
NR McCabe ◽  
MJ Thirman ◽  
RA Larson ◽  
MM Le Beau ◽  
...  

Abstract Chromosome band 11q23 is frequently involved in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) de novo, as well as in myelodysplastic syndromes (MDS) and lymphoma. Five percent to 15% of patients treated with chemotherapy for a primary neoplasm develop therapy-related AML (t-AML) that may show rearrangements, usually translocations involving band 11q23 or, less often, 21q22. These leukemias develop after a relatively short latent period and often follow the use of drugs that inhibit the activity of DNA-topoisomerase II (topo II). We previously identified a gene, MLL (myeloid-lymphoid leukemia or mixed-lineage leukemia), at 11q23 that is involved in the de novo leukemias. We have studied 17 patients with t-MDS/t-AML, 12 of whom had cytogenetically detectable 11q23 rearrangements. Ten of the 12 t-AML patients had received topo II inhibitors and 9 of these, all with balanced translocations of 11q23, had MLL rearrangements on Southern blot analysis. None of the patients who had not received topo II inhibitors showed an MLL rearrangement. Of the 5 patients lacking 11q23 rearrangements, some of whom had monoblastic features, none had an MLL rearrangement, although 4 had received topo II inhibitors. Our study indicates that the MLL gene rearrangements are similar both in AML that develops de novo and in t-AML. The association of exposure to topo II- reactive chemotherapy with 11q23 rearrangements involving the MLL gene in t-AML suggests that topo II may play a role in the aberrant recombination events that occur in this region both in AML de novo and in t-AML.


Blood ◽  
2011 ◽  
Vol 117 (7) ◽  
pp. 2137-2145 ◽  
Author(s):  
Sabine Kayser ◽  
Konstanze Döhner ◽  
Jürgen Krauter ◽  
Claus-Henning Köhne ◽  
Heinz A. Horst ◽  
...  

Abstract To study the characteristics and clinical impact of therapy-related acute myeloid leukemia (t-AML). 200 patients (7.0%) had t-AML and 2653 de novo AML (93%). Patients with t-AML were older (P < .0001) and they had lower white blood counts (P = .003) compared with de novo AML patients; t-AML patients had abnormal cytogenetics more frequently, with overrepresentation of 11q23 translocations as well as adverse cytogenetics, including complex and monosomal karyotypes, and with underrepresentation of intermediate-risk karyotypes (P < .0001); t-AML patients had NPM1 mutations (P < .0001) and FLT3 internal tandem duplications (P = .0005) less frequently. Younger age at diagnosis of primary malignancy and treatment with intercalating agents as well as topoisomerase II inhibitors were associated with shorter latency periods to the occurrence of t-AML. In multivariable analyses, t-AML was an adverse prognostic factor for death in complete remission but not relapse in younger intensively treated patients (P < .0001 and P = .39, respectively), relapse but not death in complete remission in older, less intensively treated patients (P = .02 and P = .22, respectively) and overall survival in younger intensively treated patients (P = .01). In more intensively treated younger adults, treatment-related toxicity had a major negative impact on outcome, possibly reflecting cumulative toxicity of cancer treatment.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2544-2544
Author(s):  
Xiuli Wang ◽  
Haiping Dai ◽  
Qian WANG ◽  
Qinrong Wang ◽  
Yang Xu ◽  
...  

Abstract Abstract 2544 Somatic mutation of the EZH2 gene is seen in myelodisplastic syndrome, myelofibrosis, and chronic myelomonocytic leukemia patients. The prevalence and prognostic impact of somatic mutations of EZH2 in patients with acute myelogenous leukemia (AML) remains unknown. In this study, we sought to determine the incidence and clinical implications of somatic EZH2 mutations in 714 patients with de novo AML by PCR amplification of the entire coding region followed by direct bidirectional DNA sequencing. EZH2 mutations were identified in 13/714 (1.8%) of AML patients and occurred almost exclusively in males (11/13, P=0.033). In univariate analysis, the presence of EZH2 mutations was significantly associated with lower blast percentage (21–30%) in bone marrow (P=0.0001) and −7/del(7q) (P=0.025). There was no difference in the incidence of mutations in 13 genes, including ASXL1, CBL, c-KIT, DNMT3A, FLT3, IDH1, IDH2, MLL, NPM1, NRAS, RUNX1, TET2, and WT1, between patients with and without EZH2 mutations. Complete remission, event-free survival or overall survival was similar between AML patients with and without EZH2 mutation (p>0.05). These results demonstrated EZH2 mutation as a recurrent genetic abnormality associated with lower blast percentage in BM and −7/del(7q) in de novo acute myeloid leukemia. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3801-3801 ◽  
Author(s):  
Maro Ohanian ◽  
Hagop M. Kantarjian ◽  
Farhad Ravandi ◽  
Gautam Borthakur ◽  
Guillermo Garcia-Manero ◽  
...  

Abstract Background: Essential to cancer cell signaling, the growth receptor bound protein-2 (Grb-2) is evolutionarily conserved and utilized by oncogenic tyrosine kinases including Bcr-Abl to activate Ras, ERK, and AKT. BP-100-1.01is a neutrally-charged, liposome-incorporated antisense designed to inhibit Grb-2 expression. Aim: To define the safety, maximum tolerated dose (MTD), optimal biologically active dose, pharmacokinetics and anti-leukemia activity of BP-100-1.01 in patients (pts) with hematologic malignancies. Methods: This is a standard 3+3 phase I dose-finding study in pts with relapsed or refractory acute myeloid leukemia (AML), chronic myeloid leukemia in blast phase (CML-BP), acute lymphoblastic leukemia (ALL) and myelodysplastic syndrome (MDS). The starting dose was 5 mg/m2 twice weekly, IV over 2-3 hours for 28 days. Dose escalation proceeded through 5, 10, 20, 40, 60, and 90 mg/m2.Uponcompletion of single agent phase 1, combination of cytarabine 20 mg SubQ BID x 10 days + 60 mg/m2 of BP-100-1.01 was studied (Cohort 1B). Flow cytometric analysis was performed on peripheral blood samples from cohorts 3, 4, 5, 6 and 1B collected at baseline, on day 15 and at end-of-treatment (EOT). Fluorescent-labeled antibodies specific for Grb-2 or phosphorylated Erk (pErk) were utilized to determine Grb-2 protein levels and pErk levels in CD33-expressing cells. Results: A total of33 pts were included (13 in Cohort 1, 6 in Cohort 2, 3 each in Cohorts 3, 4, 5, and 4 in cohort 6). One patient has been treated in cohort 1B. The median age was 64 yrs (range, 32-89) and diagnoses were AML (n=24), CML-BP (n=5) and MDS (n=4). The median number of prior therapies was 4 (range, 1- 8). Of 33 pts, 21 were evaluable and 11 failed completion of a full 28-Day cycle due to disease progression (with no toxicity) and were replaced, per protocol. Only one pt (treated at 5 mg/m2) experienced dose limiting toxicity (DLT), grade 3 mucositis and hand-foot syndrome, while receiving concurrent hydroxyurea for proliferative CML-BP. The patient had a previous history of hydroxyurea-induced mucositis. Being the first patient to receive BP-100-1.01, these toxicities were considered possibly related to BP-100-1.01. The cohort was expanded to a total of 6 pts. No other DLTs have been noted in any pt. Among 21 evaluable pts, 11 experienced at least a 50% reduction in peripheral or bone marrow blasts from baseline. Additionally 2 pts with improvement in leukemia cutis lesions received 1 cycle each. Furthermore, 6 pts demonstrated transient improvement (n=3) and/or stable disease (n=3). Among the 21 evaluable pts, a median of 1 cycle was administered (1-5): Four pts received 2 cycles, 3 pts received 5 cycles, and all others received 1 cycle. Notably one pt (treated at 5 mg/m2)with CML-BP showed a significant reduction in blasts from 81% to 5%. Due to leptomeningeal disease progression therapy was discontinued before a full cycle. The 1st patient treated in cohort 1B achieved CR after 1 cycle. The patient did not experience any DLTs, but came off study due to failure to thrive in the context of dementia. The levels of Grb-2 and pErk proteins were indicated by their respective median fluorescent signals and are shown in the table. Median fluorescent signals of Grb-2 and pErk on days 15 and EOT were compared to baseline. On day 15 Grb-2 levels decreased by >25% in 7 out of 12 samples tested, and pErk levels by >25% in 6 out of 12 samples. The average decrease in Grb-2 levels was 61% (range: 47 to 85%) and in pErk levels 52% (range: 28 to 82%). On the last measured sample (EOT or day 22), BP-100-1.01 decreased >25% Grb-2 levels in 11 out of 13 samples, and >25% pErk levels in 7 out of 13 samples. The average decrease in Grb-2 levels was 49% (range: 28 to 91%) and in pErk levels was 52% (range: 27 to 91%). Table 1. Patient Number Grb-2 decrease (Day 15) pErk decrease (Day 15) Grb-2 decrease (Day 22 or EOT) pErk decrease (Day 22 or EOT) 022 0 0 57 0 023 0 3 28 45 024 56 28 47 35 025 63 82 54 91 026 47 0 0 0 027 NS NS 34 27 028 0 0 30 54 029 57 51 65a 0a 030 54 55 43 47 031 0 0 0 0 032 85 54 91 63 033 6 13 53 2 034 63 42 40 0 NS = no sample collected aFewer cells were used in the analysis of this sample than other samples, because this sample had less cells than other samples Conclusions: BP-100-1.01, at dose range 5 mg/m2 to 90 mg/m2 is well tolerated with no MTD yet identified. There is suggestion of Grb-2 target protein down-regulation, and possible anti-leukemia activity. Disclosures Konopleva: Novartis: Research Funding; AbbVie: Research Funding; Stemline: Research Funding; Calithera: Research Funding; Threshold: Research Funding. Tari:Bopath Holdings: Employment. Cortes:BerGenBio AS: Research Funding; Teva: Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Astellas: Consultancy, Research Funding; Ambit: Consultancy, Research Funding; Arog: Research Funding; Celator: Research Funding; Jenssen: Consultancy.


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