| 1. |
- Jadersten, M., et al.
(författare)
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Targeting SAMHD1 with hydroxyurea in first-line cytarabine-based therapy of newly diagnosed acute myeloid leukaemia: Results from the HEAT-AML trial
- 2022
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 292:6, s. 925-940
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Tidskriftsartikel (refereegranskat)abstract
- Background Treatment of newly diagnosed acute myeloid leukaemia (AML) is based on combination chemotherapy with cytarabine (ara-C) and anthracyclines. Five-year overall survival is below 30%, which has partly been attributed to cytarabine resistance. Preclinical data suggest that the addition of hydroxyurea potentiates cytarabine efficacy by increasing ara-C triphosphate (ara-CTP) levels through targeted inhibition of SAMHD1. Objectives In this phase 1 trial, we evaluated the feasibility, safety and efficacy of the addition of hydroxyurea to standard chemotherapy with cytarabine/daunorubicin in newly diagnosed AML patients. Methods Nine patients were enrolled and received at least two courses of ara-C (1 g/m(2)/2 h b.i.d. d1-5, i.e., a total of 10 g/m(2) per course), hydroxyurea (1-2 g d1-5) and daunorubicin (60 mg/m(2) d1-3). The primary endpoint was safety; secondary endpoints were complete remission rate and measurable residual disease (MRD). Additionally, pharmacokinetic studies of ara-CTP and ex vivo drug sensitivity assays were performed. Results The most common grade 3-4 toxicity was febrile neutropenia (100%). No unexpected toxicities were observed. Pharmacokinetic analyses showed a significant increase in median ara-CTP levels (1.5-fold; p = 0.04) in patients receiving doses of 1 g hydroxyurea. Ex vivo, diagnostic leukaemic bone marrow blasts from study patients were significantly sensitised to ara-C by a median factor of 2.1 (p = 0.0047). All nine patients (100%) achieved complete remission, and all eight (100%) with validated MRD measurements (flow cytometry or real-time quantitative polymerase chain reaction [RT-qPCR]) had an MRD level <0.1% after two cycles of chemotherapy. Treatment was well-tolerated, and median time to neutrophil recovery >1.0 x 10(9)/L and to platelet recovery >50 x 10(9)/L after the start of cycle 1 was 19 days and 22 days, respectively. Six of nine patients underwent allogeneic haematopoietic stem-cell transplantation (allo-HSCT). With a median follow-up of 18.0 (range 14.9-20.5) months, one patient with adverse risk not fit for HSCT experienced a relapse after 11.9 months but is now in second complete remission. Conclusion Targeted inhibition of SAMHD1 by the addition of hydroxyurea to conventional AML therapy is safe and appears efficacious within the limitations of the small phase 1 patient cohort. These results need to be corroborated in a larger study.
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| 2. |
- Deneberg, Stefan, et al.
(författare)
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microRNA-34b/c on chromosome 11q23 is aberrantly methylated in chronic lymphocytic leukemia
- 2014
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 9:6, s. 910-917
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Tidskriftsartikel (refereegranskat)abstract
- A commonly deleted region in chronic lymphocytic leukemia (CLL) is the 11q22-23 region, which encompasses the ATM gene. Evidence suggests that tumor suppressor genes other than ATM are likely to be involved in CLL with del(11q). A microRNA (miR) cluster including the miR-34b and miR-34c genes is located, among other genes, within the commonly deleted region (CDR) at 11q. Interestingly, these miRs are part of the TP53 network and have been shown to be epigenetically regulated. In this study, we investigated the expression and methylation status of these miRs in a well-characterized cohort of CLL, including cases with/without 11q-deletion. We show that the miR-34b/c promoter was aberrantly hypermethylated in a large proportion of CLL cases (48%, 25/52 cases). miR-34b/c expression correlated inversely to DNA methylation (P = 0.003), and presence of high H3K37me3 further suppressed expression regardless of methylation status. Furthermore, increased miR-34b/c methylation inversely correlated with the presence of 11q-deletion, indicating that methylation and del(11q) independently silence these miRs. Finally, 5-azacytidine and trichostatin A exposure synergistically increased the expression of miR-34b/c in CLL cells, and transfection of miR-34b or miR-34c into HG3 CLL cells significantly increased apoptosis. Altogether, our novel data suggest that miR-34b/c is a candidate tumor suppressor that is epigenetically silenced in CLL.
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| 3. |
- Neddermeyer, Anne H.
(författare)
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Identification and Functional Significance of Aberrant Long Non-coding RNAs in Acute Myeloid Leukemia : Biological and Prognostic Implications
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute myeloid leukemia (AML) is the most frequently diagnosed type of acute leukemia in adults. It commonly affects people aged 60 or older, as incidence increases with age, and it is characterized by the accumulation of immature hematopoietic progenitor cells in the bone marrow. Despite recent treatment advances and improvements for certain subtypes, as acute promyelocyte leukemia (APL), AML remains difficult to cure. While many patients reach remission after induction treatment, relapses are common and 5-year overall survival remains dismal. Long non-coding RNAs (lncRNAs) are involved in various regulatory cellular functions and, like coding genes, they are frequently dysregulated in cancer. In this thesis, the aim was to elucidate the functional implications of lncRNAs in the biology and treatment response of AML and normal hematopoiesis in order to improve understanding of AML pathology. In Paper I, whole-transcriptome sequencing identified the novel lncRNA MALNC. Clinical correlation analyses and CRISPR-knockout cell models were used to functionally explore its implications in AML. It was identified that enhanced MALNC expression is specifically associated with the AML-subtypes APL and AML with co-mutant NPM1/IDH2R140. Further, it was shown that MALNC is implicated in key factors of leukemogenesis, like differentiation and proliferation, and that MALNC expression associates with better overall survival in AML patients. Moreover, knockout of the MALNC gene sensitized AML cells to arsenic trioxide (ATO), all-trans retinoic acid (ATRA)-ATO combination and venetoclax treatment. In Paper II, three high-throughput functional CRISPR interference screens were performed to identify lncRNAs implicated in proliferation, differentiation or venetoclax response. Several novel lncRNAs were identified to potentially play a positive or negative role in these processes and furthermore were found to implicate AML prognosis. In Paper III, the lncRNA NEAT1 was studied in respect to its role in normal hematopoiesis and AML using CAGE- and RADICL-sequencing. It could be illustrated that NEAT1 expression positively correlates with cell maturity during normal hematopoiesis, in particular monocytes, and associates with core-binding factor AML inv(16) and t(8;21). Further, RADICL-sequencing identified that lncRNA NEAT1 binds to the genomic loci of key hematopoietic transcription factor RUNX2. In contrast to solid cancers, it was demonstrated, that higher NEAT1 expression correlated with better outcome in AML, independent of known risk factors. In summary, these studies have outlined the scope of functional implications of lncRNAs in normal and dysregulated hematopoiesis and have highlighted their potential roles as biomarkers for prognosis and drug sensitivity. These findings support the efforts to understand how lncRNAs could serve as novel biomarkers for personalized treatment.
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| 4. |
- Juliusson, Gunnar, et al.
(författare)
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Age and acute myeloid leukemia : real world data on decision to treat and outcomes from the Swedish Acute Leukemia Registry
- 2009
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Ingår i: Blood. - Washington D.C. : American Society of Haematology. - 0006-4971 .- 1528-0020. ; 113:18, s. 4179-4187
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Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is most common in the elderly, and most elderly are thought to be unfit for intensive treatment because of the risk of fatal toxicity. The Swedish Acute Leukemia Registry covers 98% of all patients with AML (nonacute promyelocytic leukemia) diagnosed in 1997 to 2005 (n = 2767), with a median follow-up of 5 years, and reports eligibility for intensive therapy, performance status (PS), complete remission rates, and survival. Outcomes were strongly age and PS dependent. Early death rates were always lower with intensive therapy than with palliation only. Long-term survivors were found among elderly given intensive treatment despite poor initial PS. Total survival of elderly AML patients was better in the geographic regions where most of them were given standard intensive therapy. This analysis provides unique real world data from a large, complete, and unselected AML population, both treated and untreated, and gives background to treatment decisions for the elderly. Standard intensive treatment improves early death rates and long-term survival compared with palliation. Most AML patients up to 80 years of age should be considered fit for intensive therapy, and new therapies must be compared with standard induction.
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| 9. |
- Hulegardh, Erik, et al.
(författare)
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Characterization and prognostic features of secondary acute myeloid leukemia in a population-based setting : A report from the Swedish Acute Leukemia Registry
- 2015
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Ingår i: American Journal of Hematology. - : Wiley-Blackwell. - 0361-8609 .- 1096-8652. ; 90:3, s. 208-214
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Tidskriftsartikel (refereegranskat)abstract
- Patients with secondary acute myeloid leukemia (AML) often escape inclusion in clinical trials and thus, population-based studies are crucial for its accurate characterization. In this first large population-based study on secondary AML, we studied AML with an antecedent hematological disease (AHD-AML) or therapy-related AML (t-AML) in the population-based Swedish Acute Leukemia Registry. The study included 3,363 adult patients of which 2,474 (73.6%) had de novo AML, 630 (18.7%) AHD-AML, and 259 (7.7%) t-AML. Secondary AML differed significantly compared to de novo AML with respect to age, gender, and cytogenetic risk. Complete remission (CR) rates were significantly lower but early death rates similar in secondary AML. In a multivariable analysis, AHD-AML (HR 1.51; 95% CI 1.26-1.79) and t-AML (1.72; 1.38-2.15) were independent risk factors for poor survival. The negative impact of AHD-AML and t-AML on survival was highly age dependent with a considerable impact in younger patients, but without independent prognostic value in the elderly. Although patients with secondary leukemia did poorly with intensive treatment, early death rates and survival were significantly worse with palliative treatment. We conclude that secondary AML in a population-based setting has a striking impact on survival in younger AML patients, whereas it lacks prognostic value among the elderly patients. Am. J. Hematol. 90:208-214, 2015.
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| 10. |
- Mer, Arvind Singh, et al.
(författare)
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Expression levels of long non-coding RNAs are prognostic for AML outcome
- 2018
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Ingår i: Journal of Hematology & Oncology. - : BIOMED CENTRAL LTD. - 1756-8722. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long non-coding RNA (lncRNA) expression has been implicated in a range of molecular mechanisms that are central in cancer. However, lncRNA expression has not yet been comprehensively characterized in acute myeloid leukemia (AML). Here, we assess to what extent lncRNA expression is prognostic of AML patient overall survival (OS) and determine if there are indications of lncRNA-based molecular subtypes of AML. Methods: We performed RNA sequencing of 274 intensively treated AML patients in a Swedish cohort and quantified lncRNA expression. Univariate and multivariate time-to-event analysis was applied to determine association between individual lncRNAs with OS. Unsupervised statistical learning was applied to ascertain if lncRNA-based molecular subtypes exist and are prognostic. Results: Thirty-three individual lncRNAs were found to be associated with OS (adjusted p value < 0.05). We established four distinct molecular subtypes based on lncRNA expression using a consensus clustering approach. LncRNA-based subtypes were found to stratify patients into groups with prognostic information (p value < 0.05). Subsequently, lncRNA expression-based subtypes were validated in an independent patient cohort (TCGA-AML). LncRNA subtypes could not be directly explained by any of the recurrent cytogenetic or mutational aberrations, although associations with some of the established genetic and clinical factors were found, including mutations in NPM1, TP53, and FLT3. Conclusion: LncRNA expression-based four subtypes, discovered in this study, are reproducible and can effectively stratify AML patients. LncRNA expression profiling can provide valuable information for improved risk stratification of AML patients.
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