scholarly journals Mutation detection in thousands of acute myeloid leukemia cells using single cell RNA-sequencing

2018 ◽  
Author(s):  
Allegra A. Petti ◽  
Stephen R. Williams ◽  
Christopher A. Miller ◽  
Ian T. Fiddes ◽  
Sridhar N. Srivatsan ◽  
...  

AbstractVirtually all tumors are genetically heterogeneous, containing subclonal populations of cells that are defined by distinct mutations1. Subclones can have unique phenotypes that influence disease progression2, but these phenotypes are difficult to characterize: subclones usually cannot be physically purified, and bulk gene expression measurements obscure interclonal differences. Single-cell RNA-sequencing has revealed transcriptional heterogeneity within a variety of tumor types, but it is unclear how this expression heterogeneity relates to subclonal genetic events – for example, whether particular expression clusters correspond to mutationally defined subclones3,4,5,6-9. To address this question, we developed an approach that integrates enhanced whole genome sequencing (eWGS) with the 10x Genomics Chromium Single Cell 5’ Gene Expression workflow (scRNA-seq) to directly link expressed mutations with transcriptional profiles at single cell resolution. Using bone marrow samples from five cases of primary human Acute Myeloid Leukemia (AML), we generated WGS and scRNA-seq data for each case. Duplicate single cell libraries representing a median of 20,474 cells per case were generated from the bone marrow of each patient. Although the libraries were 5’ biased, we detected expressed mutations in cDNAs at distances up to 10 kbp from the 5’ ends of well-expressed genes, allowing us to identify hundreds to thousands of cells with AML-specific somatic mutations in every case. This data made it possible to distinguish AML cells (including normal-karyotype AML cells) from surrounding normal cells, to study tumor differentiation and intratumoral expression heterogeneity, to identify expression signatures associated with subclonal mutations, and to find cell surface markers that could be used to purify subclones for further study. The data also revealed transcriptional heterogeneity that occurred independently of subclonal mutations, suggesting that additional factors drive epigenetic heterogeneity. This integrative approach for connecting genotype to phenotype in AML cells is broadly applicable for analysis of any sample that is phenotypically and genetically heterogeneous.

Author(s):  
Adeline Crinier ◽  
Pierre-Yves Dumas ◽  
Bertrand Escalière ◽  
Christelle Piperoglou ◽  
Laurine Gil ◽  
...  

SummaryNatural killer (NK) cells are innate cytotoxic lymphoid cells (ILCs) involved in the killing of infected and tumor cells. Among human and mouse NK cells from the spleen and blood, we previously identified by single-cell RNA sequencing (scRNAseq) two similar major subsets, NK1 and NK2. Using the same technology, we report here the identification, by single-cell RNA sequencing (scRNAseq), of three NK cell subpopulations in human bone marrow. Pseudotime analysis identified a subset of resident CD56bright NK cells, NK0 cells, as the precursor of both circulating CD56dim NK1-like NK cells and CD56bright NK2-like NK cells in human bone marrow and spleen under physiological conditions. Transcriptomic profiles of bone marrow NK cells from patients with acute myeloid leukemia (AML) exhibited stress-induced repression of NK cell effector functions, highlighting the profound impact of this disease on NK cell heterogeneity. Bone marrow NK cells from AML patients exhibited reduced levels of CD160, but the CD160high group had a significantly higher survival rate.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3107-3107
Author(s):  
Ian McInnis ◽  
Theresa Hahn ◽  
Anasitasia Ioane ◽  
Ashleigh Lamson ◽  
Deepika Lal ◽  
...  

Abstract Abstract 3107 Poster Board III-44 Prior studies have demonstrated that hepatocyte growth factor (HGF) regulates proliferation and differentiation of normal hematopoietic progenitors. HGF activity occurs primarily via interactions with the c-met receptor, a tyrosine kinase receptor found on epithelial and some cancer cells. In solid tumors, HGF/c-met interactions mediate increased neoplastic invasion, metastases, and angiogenesis. However, in vitro, HGF has also been shown to mediate anti-tumor effects in leukemia cell line models. To better elucidate the role of HGF in acute leukemogenesis, we evaluated HGF and c-met gene expression in 91 normal karyotype acute myeloid leukemia (NK-AML) patient samples previously characterized for marrow angiogenesis (CD31+ microvessels), FLT-3/NPM-1 gene mutation, and pro-angiogenic factors and receptors (specifically vascular endothelial growth factors (VEGF-A and C) and their receptors). Median patient age was 66 years (range 21-87) with 49 women and 42 men. AML disease FAB subtypes M2 (37%) and M1 (36%) subtypes were most common. Median presenting white blood cell count (WBC) was 32,000/μL (range 0.43-555,000/μL) with marrow blasts of 70.6% (range 15-95.4%). Fourteen percent presented with extramedullary disease. Median OS was 9.4 months (95% CI 6.7 to 11.5 months), with median EFS of 8 months (95% CI 5.7 to 11.5 months) for all patients. Seventy-nine patients received cytarabine and anthracycline-based induction chemotherapy with 58% (n=46) achieving complete remission (CR). Marrow aspirate samples were evaluated by quantitative real-time polymerase chain reaction with levels expressed relative to normal bone marrow controls (set =1). We found that HGF gene expression was upregulated in most primary NK-AML patient samples, with 88% expressing higher HGF than normal bone marrow. Median HGF expression in AML samples was 7.73 fold higher than normal controls. Multivariate analysis including age, complete remission, marrow blasts, extramedullary disease, and expression of other angiogenic factors and receptors as covariables, showed high HGF expression to be significantly associated with both longer overall and event-free survival. Surprisingly, HGF gene expression was found to be negatively correlated with microvessel density and NPM-1 mutation and positively correlated with the VEGF receptor neuropilin-1 (NRP-1) which has been reported to function as co-mediator of HGF activity. No association between HGF and FLT-3 ITD mutation was noted. The majority of AML samples did not express the HGF receptor, c-met, suggesting that HGF function in AML occurs primarily via paracrine interactions with surrounding vascular and stromal cells and/or HGF/NRP-1 autocrine pathways. Further analysis confirmed no significant correlation between HGF and c-met gene expression in AML samples but did demonstrate a subset of NPM-1+ HGF+ AML samples (n=7) expressing high levels of both HGF and c-met (p=0.0005, r=0.96). To confirm whether HGF/c-met autocrine interactions contributed to leukemogenesis in these cells, we treated immunodeficient mice engrafted with an HGF+ c-met+ human AML cell line (HEL) with vehicle vs. a c-met tyrosine kinase inhibitor, and noted growth inhibitory effects following c-met blockade. Conclusions HGF gene expression was an independent predictive factor for improved clinical outcome and was associated with NRP-1 expression, lower microvessel density, and NPM-1 negative status in normal karyotype AML patients. A subset of AML samples was identified with high concordant HGF and c-met expression consistent with autocrine pathways. Inhibition of HGF/c-met interactions in a preclinical AML model exerted anti-tumor effects. Additional studies of the diverse roles of HGF in myeloid leukemogenesis are warranted. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4945-4945 ◽  
Author(s):  
Poonkuzhali Balasubramanian ◽  
Ashok kumar Jayavelu ◽  
Ajay Abraham ◽  
Savitha Varatharajan ◽  
Sreeja Karathedath ◽  
...  

Abstract Acute myeloid leukemia (AML) is a clinically and biologically complex and heterogeneous hematopoietic neoplasm. Recent advances in acute myeloid leukemia (AML) biology have lead to prognosticate and predict treatment outcome in AML based on molecular markers. Mutations in NPM1, CEBPA are considered good prognosis and High BAALC, ERG & MN1 expression associate with worse outcome in AML patients treated with standard chemotherapy. Although many efforts have been made to identify genetic mutations and modulated gene expression levels that can be used to predict outcomes in patients with AML, the association between these prognostic markers has not been evaluated. We have reported previously that the NPM1 mutated patients have significantly high dCK and hENT1 gene expression (involved in cytarabine metabolism) and low ABCG2 and ABCB1transporter expression (Abraham et al, ASH abstracts; Nov 2011; 118: 3481 and Nov 2012; 120: 143), suggesting that the good prognostic nature of this mutation is possibly due to the better metabolism and transport of the chemotherapeutic drugs used in induction therapy.  We extended this study to look for association between NPM1/FLT3 mutation status and the RNA expression of other good or poor prognostic markers in patients with AML. We prospectively included 274 adult patients with AML in this study. The median age was 42 years (range 16-74y). AML was diagnosed according to the FAB and WHO classifications. There were 238 patients with de novo AML; Secondary AML -6; Therapy related AML- 2 and Relapsed AML-28. Bone marrow cytogenetics and immunophenotyping analysis was available for all patients at diagnosis and/or relapse. Diagnostic bone marrow MNCs were isolated by ficoll- density gradient centrifugation and stored in trizol reagent for RNA expression and mutation detection. RT-PCR was used to screen AML-ETO and Inv 16, and the expression of BAALC, ERG1, MN1, CXCR4 and WT1were analyzed using RQ-PCR. NPM1-c, FLT3 ITD and TKD were screened using DNA PCR followed by gene-scan, sequencing or RFLP methods. The basic demographics and the frequency of the markers are listed in Table 1. When analyzed separately in normal karyotype AML (NK-AML), the frequencies of the mutations were: NPM1: 52.2%; FLT3-ITD: 24%; TKD: 4.3%. When the RNA expression of BAALC, WT1, ERG1, CXCR4 and MN1 was compared in patients with NPM1 or FLT3 mutations, we noticed that patients with NPM1 had significantly low expression of BAALC, MN1 and ERG1 while those with FLT3 mutations (ITD or TKD) had higher expression of these genes (Figure1). There was no significant association with CXCR4 or WT1 expression and these mutations. When analyzed separately in the normal karyotype AML, these associations were still significant. In addition, the relapsed patients had significantly higher expression of BAALC, MN1, and ERG1 RNA compared to de-novoAML cases (data not shown). To conclude, we show that NPM1 or FLT3 mutations acquire the prognostic significance due to several factors including BAALC, ERG1 and MN1expression levels in addition to drug metabolizing enzymes’ and drug transporter expression. These factors must be taken into consideration when attempting to personalize chemotherapy in AML. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 4-4
Author(s):  
Ashley Zhang ◽  
Yuntao Liu ◽  
Shuning Wei ◽  
Benfa Gong ◽  
Chunlin Zhou ◽  
...  

Background BCOR gene is a transcription repressor that may influence normal hematopoiesis and is associated with poor prognosis in acute myeloid leukemia (AML) with normal karyotype. However, due to the rare mutation frequency in AML (3.8%-5%), clinical characteristics and prognosis of AML patients with BCOR mutation including abnormal karyotype are still unknown. In addition, the clonal evolution of AML patients with BCOR mutation has not been fully investigated. Methods By means of next generation of sequencing, we performed sequencing of 114 genes related to hematological diseases including BCOR on 509 newly diagnosed AML patients (except for acute promyelocytic leukemia) from March 2017 to April 2019. The 2017 European Leukemia Net (ELN) genetic risk stratification was used to evaluate prognosis. Overall survival (OS) was defined as the time from diagnosis to death or last follow-up. Relapse-free survival (RFS) was measured from remission to relapse or death. Clonal evolution was investigated through analyzing bone marrow samples at diagnosis, complete remission (CR) and relapse from the same patient. Result Among 509 AML patients, we found BCOR mutations in 23 patients (4.5%). BCOR mutations were enriched in patients with mutations of RUNX1 (p = 0.008) and BCORL1 (p = 0.0003). Patients with BCOR mutation were more at adverse ELN risk category compared to patients without BCOR mutation (p = 0.007). Besides, there was a larger proportion of patients with normal karyotype in BCOR mutation group but it had not reached statistical difference (62.5% vs 45.5%, p = 0.064). The abnormal karyotype in patients with BCOR mutations included trisomy 8, t(9;11), inv(3), -7 and complex karyotype.There were no significant differences in age, sex, white blood cell count, hemoglobin or platelet count between the two groups. More patients died during induction (13.0% vs 3.5%, p = 0.56) and fewer patients achieved CR after 2 cycles of chemotherapy when patients had BCOR mutations (69.6% vs 82.5%, p = 0.115) but the difference had not reached statistical difference . Patients with BCOR mutations had inferior 2-year OS (52.1% vs 70.7%, p = 0.0094) and 2-year RFS (29.8% vs 61.1%, p = 0.0090). After adjustment for ELN risk stratification, BCOR mutation was still remain a poor prognostic factor. However, the adverse prognostic impact of BCOR mutation is overcome by hematopoietic stem cell transplantation (HSCT), in which there was no difference between BCOR mutation group and wild type group (p = 0.474) (Figure 1). Through analysis of paired bone marrow sample at diagnosis, remission and relapse, we revealed the clonal evolution that BCOR mutation was only detected at diagnosis sample as a subclone and diminished at CR and relapse while TP53 mutation was only detected at relapse with a variant allele frequency (VAF) of 25.5%. We also found BCOR mutation at another patient's diagnosis and relapse sample while TP53 mutation was detected at relapse with VAF of 11.8%. Conclusion BCOR is associated with RUNX1 mutation and higher ELN risk. AML patients with BCOR mutation including normal and abnormal karyotype conferred a worse impact on OS that can be overcome by HSCT. BCOR mutation is a subclone at diagnosis or relapse in some patients, in which TP53 mutation clone occurred at relapse. Disclosures No relevant conflicts of interest to declare.


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