Aberrant Gene Expression of BAALC and ERG in Older [≥60 Years (y)] De Novo Cytogenetically Normal Acute Myeloid Leukemia (CN-AML): A Cancer and Leukemia Group B (CALGB) Study.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 214-214
Author(s):  
Sebastian Schwind ◽  
Guido Marcucci ◽  
Kati Maharry ◽  
Krzysztof Mrózek ◽  
Michael D. Radmacher ◽  
...  

Abstract Abstract 214 BAALC & ERG are aberrantly expressed in younger (<60 y) adult CN-AML patients (pts), where expression levels of these genes are also associated with clinical outcome. Whether aberrant BAALC & ERG expression also occurs in older (≥60 y) CN-AML pts is unknown. To assess the BAALC & ERG expression levels in older CN-AML & their impact on outcome we studied pts ≥60 y (median age, 68 y; range 60–83) enrolled on cytarabine/daunorubicin-based protocols [CALGB 10201, 9720, 9420, 8923, 8525], with diagnostic blood samples available for quantitative RT-PCR analysis (n=158), that were also characterized for other molecular prognosticators (FLT3-ITD, FLT3-TKD, NPM1 & WT1 mutations). BAALC & ERG expression values were normalized to an internal control (ABL1), & the median gene expression value was used to define high & low expressers for BAALC & ERG. Gene (GEP) & microRNA (MEP) expression profiling were done using, respectively, Affymetrix U133 plus 2.0 & OSU CCC v4.0 arrays. At diagnosis, lower BAALC expression was associated with mutated NPM1 (P<.001) & low ERG expression (P<.001). Lower BAALC expressers had a higher complete remission rate (CR; 86% v 54%, P<.001) & longer disease-free (DFS; P=.006; 3y rates 19% v 12%) & overall survival (OS; P<.001; 3y 29% v 10%) than higher expressers. Lower ERG expression was associated with lower WBC (P=.005), % marrow (BM; P=.001) & blood (P<.001) blasts & absent FLT3-ITD (P<.001) & low BAALC expression (P<.001). Lower ERG expression also associated with longer DFS (P=.001; 3y 18% v 14%) & OS (P<.001; 3y 24% v 15%). In multivariable models (Table 1), low BAALC expression independently associated with CR & longer DFS. BAALC & ERG expression were the only factors associated with OS. Comparison of age-groups (60-69 y v ≥70 y; Table 2) showed BAALC expression had a stronger prognostic impact in ≥70 y pts; lower expression was associated with higher CR rates & longer DFS & OS. ERG expression had instead stronger prognostic impact in 60-69 y pts (Table 2); lower expression was associated with longer DFS & OS. GEP (482 probes) & MEP (22 probes) differentiated low from high BAALC expressers. Low BAALC expressers had down-regulation of stem cell markers (CD34, CD133) & unfavorable outcome predictors (HGF, MN1, CD200), & up-regulation of HOX genes & miR-10a & miR-10b. GEP (1554 probes) & MEP (11 probes) differentiating low from high ERG expressers showed low ERG expressers had down-regulation of DNMT3B & up-regulation of topoisomerase 1 (TOP1), which is associated with enhanced chemotherapy sensitivity. Among up-regulated microRNAs in low ERG expressers was miR-208a, which is predicted to target ERG. In conclusion, lower expression of both BAALC & ERG associated with better outcome in older CN-AML pts even in the context of other established prognostic molecular markers, but have different impact on age-groups. GEP & MEP provided novel information that may elucidate how differential expression levels of these genes contribute to leukemogenesis & aid in developing novel risk-adapted therapies. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1081-1081
Author(s):  
Claire Abbal ◽  
Raouf Ben Abdelali ◽  
Marina Lafage ◽  
Françoise Huguet ◽  
Thibaut Leguay ◽  
...  

Abstract Background: EVI1 gene overexpression is found in approximately 10% of acute myeloid leukemia (AML) patients, with a higher frequency seen in AML carrying chromosome 3q26 abnormality or MLL gene rearrangement, and associated with a dismal prognosis. Deregulation of EVI1 expression has also been reported in ALL, but its prognostic impact is unclear. Here, we retrospectively analyzed EVI1 expression in a large cohort of adult ALL patients, its correlation with ALL subsets, and its impact on patient outcome. Patients and Methods: EVI1 gene expression was measured by RQ-PCR detecting all splicing variants, with PBGD as control gene. We used dilutions of EVI1+ SKOV3 (kindly provided by Peter Valk, Rotterdam, The Netherlands) and EVI1-neg HL-60 cell line cDNA to build EVI1 and PBGD standard curves. Results were expressed as EVI1/PBGD ratio x 100. Blast samples from 354 patients treated in the GRAALL-2003/2005 and GRAAPH-2005 trials (191 B-cell precursor [BCP]-ALL, including 138 Ph-neg and 53 Ph+; 163 T-ALL) and 62 controls were analyzed. Immunophenotype results were centrally reviewed. In controls, median EVI1 expression level was 0.33% (Q1-Q3, 0.20-0.69). For prognostic analysis, we used the 1st and 99th percentiles of the controls (0.05% and 1.65%) to define patients with low and high EVI1 expression, respectively. Clinical endpoints were cumulative incidence of failure (CIF, failure meaning primary refractoriness or relapse) and event-free survival (EFS). Results: As illustrated in Figure 1, we observed that, as in one AML series, EVI1 expression may be up or down regulated in adult ALL. When compared to controls, the proportions of low and high EVI1 patients were 21 and 23% in Ph-neg BCP-ALL, 9 and 42% in Ph+ ALL, and 21 and 18% in T-ALL, respectively. In BCP-ALL patients, median EVI1 expression was similar to controls (0.53%; Q1-Q3, 0.11-1.88; p=0.15), but higher in the Ph+ as compared to the Ph-neg subgroup (0.93% versus 0.36%; p<0.001). In T-ALL patients, median expression tended to be lower than in controls (0.22%; Q1-Q3, 0.06-0.85; p=0.058). In these three ALL subgroups, EVI1 expression did not correlate with age or WBC. Among Ph-neg BCP-ALL patients, a lower expression was found in MLL-AF4+ t(4;11) cases (median, 0.04%; p<0.001), while no differences were observed for cases with t(1;19), an14q32, low hypodiploidy/near triploidy, complex karyotype, or IKZF1 deletion. Among T-ALL patients, a lower expression was found in cases with complex karyotype (median, 0.05%; p=0.03), while no differences were observed for cases with TLX1 overexpression, NOTCH1/FBXW7 mutation, N/K-RAS mutation or PTEN alteration. Only one patient had 3q26 abnormality (T-ALL with high EVI1 expression). Low or high EVI1 expression had no prognostic impact in Ph-neg as well as Ph+ BCP-ALL patients. In T-ALL, the proportion of patients with low EVI1 expression was more frequent in early and mature than in cortical T-ALL (33% and 33% vs 11%; p=0.002 and 0.028, respectively) and associated with a higher CIF (HR, 2.03; p=0.017) and shorter EFS (HR, 1.59; p=0.072). Low EVI1 expression was also significantly associated with an early T-cell precursor (ETP) phenotype (37.5% vs 18%; p=0.028). After adjustment on cortical and ETP phenotypes, as well as on 4-gene (NOTCH1/FBXW7/RAS/PTEN) genetic profiles, low EVI1 expression and high-risk genetic profiles remained independently associated with higher CIF (p=0.015 and <0.001, respectively) and shorter EFS (p=0.045 and 0.002, respectively). Conclusion: Overall, these results confirm that EVI1 gene expression is frequently deregulated in adult ALL. In BCP-ALL, down-regulation is observed in t(4;11) and up-regulation in BCR-ABL cases. Further studies are needed to confirm that, in T-ALL, a lower expression is associated with the early, mature and ETP phenotypes and independently predictive of a worse patient outcome. Figure 1 Figure 1. EVI1 gene expression in ALL and control samples. Disclosures No relevant conflicts of interest to declare.


2014 ◽  
Vol 23 (03) ◽  
pp. 207-211
Author(s):  
C. Kasch ◽  
A. Osterberg ◽  
Thordis Granitzka ◽  
T. Lindner ◽  
M. Haenle ◽  
...  

SummaryThe RANK/RANKL/OPG system plays an important role in the regulation of bone metabolism and bony integration around implants. The aim of this study was to analyse gene expression of OPG, RANK, and RANKL in regenerating bone during implant integration. Additionally, the effect of intermittent para - thyroid hormone (PTH) treatment was analysed. A titanium chamber was implanted in the proximal tibiae of 48 female rats. The animals received either human PTH or saline solution (NaCl). After 21 and 42 days, RNA was isolated from tissue adjacent to the implant and expression of RANK, RANKL, and OPG was analysed. After 21 days, very low expression levels of all genes were shown. In contrast, increased gene expression after 42 days was determined. Expression of RANK and RANKL was lower than that for OPG. The lower expression levels after 21 days might be due to still ossifying, fibrotic tissue around the titanium chamber. An increased OPG synthesis rate associated with decreased RANKL expression after 42 days revealed bone-forming processes. Despite significant differences in gene expression between the time points, only slight differences were observed between application of intermittent PTH and NaCl after a period of 42 days.


Endocrinology ◽  
2007 ◽  
Vol 148 (3) ◽  
pp. 1235-1245 ◽  
Author(s):  
Liwei Huang ◽  
Yongbing Pu ◽  
David Hepps ◽  
David Danielpour ◽  
Gail S. Prins

Axis positioning and tissue determination during development involve coordinated expression of Hox genes throughout the body. The most posterior Hox gene clusters are involved in prostate organogenesis. In the present study, we characterized and compared the expression profiles of posterior (5′) Hox genes in the separate lobes of the adult rat prostate gland, the coagulating gland, seminal vesicles, and epididymis using quantitative real-time RT-PCR. These genes include Hoxa9–11, Hoxa13, Hoxd13, and Hoxb13. We identified a unique Hox code for each of these organs and propose that this contributes to the organ-specific and prostate lobe-specific identities in the adult rat. Using the ventral prostate (VP) as a model, we characterized the Hox genes expression patterns over time from birth through adulthood. Expression levels of the three Hox13 genes and Hoxa10 were significantly higher in the adult VP compared with the neonatal developing VP suggesting an important role during adult homeostasis. In contrast, Hoxa9 and Hoxa11 levels declined after morphogenesis suggesting a specific developmental role. Overall, the Hoxb13 gene exhibited the most striking temporal and organ-specific differences. Using in situ hybridization and immunohistochemistry, a distinct Hoxb13 anterior-to-posterior expression gradient was observed with the highest expression levels in the VP luminal epithelial cells, moderate levels in the lateral prostate, and low expression in the dorsal prostate. An expression gradient was also observed along the ductal length in all three prostate lobes with strongest expression at the distal tips and limited expression in the proximal ducts. After infection with a lentivirus expressing the Hoxb13 gene, NRP-152 cells cultured under nondifferentiating conditions exhibited robust cytokeratin 8 immunostain indicating that Hoxb13 expression drives luminal cell differentiation in the rat epithelium. Androgen regulation of prostatic Hox gene expression was examined during development in vitro and after castration in the adult rat. In the neonatal VP, all six Hox genes were significantly up-regulated by androgens, whereas none of the genes were affected by testosterone in the lateral prostate. In the adult rat, castration resulted in up-regulation of Hoxa9 and Hoxa13 in the VP and down-regulation of Hoxb13 in the dorsal prostate and lateral prostate. Taken together, we conclude that the prostatic Hox genes reach a destined expression level at specific developmental time points in the prostate gland and possess differential androgenic regulation in a temporal and lobe-specific manner. We suggest that this timely Hox code participates in determining lobe-specific prostatic identity and cellular differentiation.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1616-1616 ◽  
Author(s):  
Eyal C. Attar ◽  
Kati Maharry ◽  
Krzysztof Mrózek ◽  
Michael D. Radmacher ◽  
Susan P. Whitman ◽  
...  

Abstract Abstract 1616 Poster Board I-642 CD74 is a type II integral membrane protein receptor that binds its ligand MIF to induce phosphorylation of the extracellular signal-regulated kinase-1/2 (ERK-1/2) and drive cellular proliferation via nuclear factor-kappa B (NF-kB) activation. CD74 expression has been identified in human solid tumors, and its expression is associated with adverse prognosis in advanced pancreatic cancer. As CD74 is expressed and NF-kB constitutively activated in myeloblasts, we hypothesized that CD74 expression might also be associated with adverse outcome in AML. To investigate the prognostic impact of CD74 expression in the context of other predictive molecular markers in CN-AML, we assessed CD74 expression levels by Affymetrix HG-U133 Plus 2.0 microarray in 102 younger [<60 years (y)] adults with primary CN-AML, treated on the front-line CALGB 19808 trial with an induction regimen containing daunorubicin, cytarabine, etoposide and, in some cases, the inhibitor of multidrug resistance valspodar, and consolidation with autologous stem cell transplantation. Microarray data were analyzed using the Robust Multichip Average method, making use of a GeneAnnot chip definition file, which resulted in a single probe-set measurement for CD74. At diagnosis, CD74 expression, when assessed as a continuous variable, was significantly associated only with extramedullary disease involvement (P=.006) among clinical features, and with none of the molecular prognostic variables tested, including NPM1, WT1, CEBPA, FLT3 (FLT3-ITD and FLT3-TKD) mutations, MLL partial tandem duplication, or differential BAALC and ERG expression levels. Although CD74 expression levels were not associated with achievement of complete remission (CR; 83% vs 81%), higher levels of CD74 were associated with shorter disease-free survival [DFS; P=.046, hazard ratio (HR) 1.85, 95% confidence interval (CI) 1.12-3.08] and with shorter overall survival (OS; P=.02, HR 1.32, CI 1.04-1.67). In multivariable analyses, higher CD74 expression was independently associated with shorter DFS (P=.045, HR 1.98, CI 1.16-3.40), after adjusting for WT1 mutations (P<.001) and FLT3-TKD (P=.04), and shorter OS (P=.01, HR 1.58, CI 1.11-2.25) after adjusting for FLT3-TKD (P=.02), WT1 mutations (P=.007), BAALC expression levels (P=.02), white blood counts (P=.007), and extramedullary involvement (P=.04). As quartiles 2-4 had similar expression levels distinct from the lowest quartile, to display the impact of CD74 expression levels on clinical outcome only, pts were dichotomized into low (the lowest quartile) and high (the top three quartiles) CD74 expressers. The Kaplan-Meier curves for DFS and OS (Figures 1 and 2) are shown below. In conclusion, our study identifies elevated CD74 expression as associated with adverse prognosis in younger CN-AML pts. Since we previously reported that higher CD74 expression was favorably associated with achievement of CR in AML patients receiving chemotherapy plus bortezomib, an inhibitor of the proteasome and NF-kB (Attar et al., Clin Cancer Res, 2008;14:1446-54), it is possible that in future studies elevated CD74 levels can be used not only for prognostication, but also to stratify CN-AML pts to study of bortezomib-containing chemotherapy regimens. Figure 1 Disease free survival Figure 1. Disease free survival Figure 2 Overall survival Figure 2. Overall survival Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5128-5128 ◽  
Author(s):  
Andrey Misurin ◽  
Tatyana Gaponova ◽  
Larisa Mendeleeva ◽  
Elena Parovichnikova ◽  
Valeryi Savchenko

Abstract High dose therapy enables further improvement in the outcome of multiple myeloma (MM) patients. However, it is still necessary to determine prognostic factors that may influence treatment results and provide additional criteria for the precise selection of treatment approaches. There are several tumor associated genes (MAGE, LAGE, GAGE, PRAME) that are over-expressed in different malignancies including MM. These genes are believed to modulate cancer properties and should be taken into account during treatment. Their significance as prognostic factors is under investigation. The aim of our study was to analyze the expression levels of PRAME and WT1 genes in MM patients during high dose chemotherapy following by auto-SCT. After having informed consent 25 primary MM patients were included into this study. The median age was 48 years (range, 31–62). All patients were treated by 3 cycles of VAD, Cyclophosphamide 6g/m2 + G-CSF to mobilize Stem cells, EDAP, melphalan 200 mg/m2 followed by auto-SCT. As second line therapy we used bortezomib+dexamethasone. Quantitative PRAME and WT1 gene expression analysis was performed by means of RQ-PCR. Results were normalized against expression of ABL gene which was used as internal control. Investigation was performed before treatment (n=25), after three VAD cycles (n=12), and before (n=5) and after auto-SCT (n=4). In primary MM patients: PRAME gene expression was found in 68% (n=17), WT1 in 24% (n=6) of patients, all of whom were PRAME-positive. Median expression levels were 0.1% (0.001–132%) for PRAME and 0.01% (0.002–0.07%) for WT1. PRAME and WT1 expression did not correlate with tumor bulk and was independent of the levels of M-protein, beta-2M and albumin. The expression of PRAME significantly decreased after 3 VAD cycles to 0.001–207% (n=8), at the moment of auto-SCT it was 0.05–6.1% (n=3) and after auto-SCT it was 0.013–4.9% (n=3). However for WT1, we observed increased of WT1 expression after 3 VAD cycles to 0.004-0.05% (n=4)and at the moment of auto-SCT it was 0.035–0.4% (n=3) and after auto-SCT – 0.019–2.03% (n=3). In the patients with high primary PRAME expression (&gt;median expression) the frequency of CR+PR was significantly lower then in PRAME-negative primary patients and in patients with low (&lt;median expression) primary PRAME expression (55% vs 84, p = 0.04). It was found also that WT1-positive primary patients were bad responders and they achieved only minimal response after 3 VAD cycles. It should be stressed that during treatment in a small number of initially negative PRAME and WT1 gene patients, we demonstrated detection by PCR. We detected the appearance of gene expression at low levels in 1 of 8 initially negative PRAME (6.1%) and in 5 of 19 initially negative WT1 (range of level 0.01–0.4%). The detection of gene expression did not correlate with disease status. All these patients achieve CR+ VGPR. In one of these secondary positive patients (acquired PRAME and WT1) relapse occurred. Conclusion: Expression of PRAME gene was found in 68% primary patients and the level of PRAME decreased with tumor reduction. High expression level of PRAME turned out to be a factor of unfavorable prognosis. Expression of WT1 was found in 24% of MM patients all of whom were PRAME-positive. WT1 expression increased during treatment in a small group of pts. Some initially negative pts acquired PRAME and WT1 expression during treatment, but clinical relevance of it is not clear so far.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 326-326
Author(s):  
Heiko Becker ◽  
Guido Marcucci ◽  
Kati Maharry ◽  
Michael D. Radmacher ◽  
Krzysztof Mrózek ◽  
...  

Abstract Abstract 326 Mutations of the Wilms tumor (WT1) gene are found in ∼10% of younger (<60 years[y]) adult pts with de novo CN-AML and impact adversely on their outcome. The clinical significance of WT1 mutations has not yet been evaluated in older (≥60 y) CN-AML pts. Therefore, we analyzed frequency and clinical impact of WT1 mutations in the context of other molecular markers in a relatively large cohort of 243 pts ≥60 y (range, 60-83 y) with de novo CN-AML treated intensively on upfront cytarabine/daunorubicin-based CALGB protocols. Included pts were those with material available for analysis of WT1 mutation status and that of a panel of other validated molecular prognosticators including NPM1, FLT3 (ie, FLT3-ITD, FLT3-TKD) and CEBPA mutations, BAALC and ERG expression levels. Mutations in WT1 “hot spots” (exons 7 and 9) were assessed by DHPLC and sequencing. The results were compared with the findings in younger (18-59 y) CALGB pts (n=207) characterized molecularly in a similar fashion. Gene expression profiles in both populations were assessed centrally using Affymetrix U133 plus 2.0 microchip. Among the 243 older pts, 16 (7%) had WT1 mutations. Of those, 14 had single WT1 mutations in exon 7 [frameshift (n=8), nonsense (n=1), and missense (n=1)] or in exon 9 [missense (n=4)]; 1 pt had 2 frameshift mutations in exon 7, and 1 had 1 frameshift mutation in exon 7 and 1 missense mutation in exon 9. Compared with older WT1 wild-type pts, older WT1 mutated pts more often had FLT3-ITD (P<.001) and had lower hemoglobin (P=.01), and higher WBC (P=.03) and % blood blasts (P=.03). WT1 mutated pts had a trend for lower complete remission (CR) rates (50% v 70%, P=.16) and shorter OS (P=.08; Figure 1), but similar disease-free survival (DFS; P=.59; Figure 2) compared with WT1 wild-type pts. The frequency of WT1 mutations tended to be lower in older than younger pts (7% v 12%, P=.07). Mutation types and pretreatment clinical and molecular characteristics associated with WT1 mutations were similar between the two age groups. Despite differences in treatment intensity, there were no significant differences in younger v older WT1 mutated pts with regard to CR rates (P=.18), or OS (P=.68; Figure 1) or DFS (P=.66; Figure 2) durations. In contrast, younger WT1 wild-type pts had significantly higher CR rates (P<.001), and longer OS (P<.001; Figure 1) and DFS (P<.001; Figure 2) than older WT1 wild-type pts. Although associated with WT1 mutations in both the younger (P=.02) and older age groups, FLT3-ITD had no impact on CR rates (P=.28), or OS (P=.15) or DFS (P=.21) durations of all WT1 mutated pts after controlling for age-related treatment intensity. To provide insights into the molecular features associated with WT1 mutations we analyzed the whole cohort (younger and older) for genes differentially expressed (ie, P≤.001) between WT1 mutated and WT1 wild-type pts. A signature comprising 110 named genes was derived. Among the 71 upregulated genes in WT1 mutated pts, were those encoding the leukemia stem cell marker CD96 and the leukemia fusion protein partners PML and MLL. The most upregulated gene (6.2 fold) was GTSF1, which, like WT1, may be involved in germ cell development. Among the 39 genes downregulated in WT1 mutated pts, were those encoding SNRPN and SNURF, involved in pre-mRNA processing, and the insulin receptor and IRS2, upstream effectors of the PI3K/AKT pathway. In conclusion, WT1 mutations in older CN-AML pts are less frequent than in younger pts. While WT1 mutations independently associate with shorter OS and DFS in younger CN-AML pts, in older CN-AML pts they are only associated with trends for a worse CR rate and shorter OS. This difference appears due to the poor outcome of the older compared to younger WT1 wild-type pts, which reduced the prognostic impact of WT1 mutations in the former. Nevertheless, the outcome of pts with WT1 mutations is equally poor in older and younger pts regardless of differences in treatment, thereby suggesting that WT1 mutated CN-AML may constitute a distinct biologic entity across age groups. The unique gene expression signature associated with WT1 mutations could provide useful insights into WT1 mutation-driven leukemogenic mechanisms across age-related groups, and help in devising novel molecular targeted therapeutic approaches for this subtype of CN-AML. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1367-1367
Author(s):  
Christine Gilling ◽  
Amit Mittal ◽  
Vincent Nganga ◽  
Vicky Palmer ◽  
Dennis D. Weisenburger ◽  
...  

Abstract Abstract 1367 Previously, we have shown that gene expression profiles (GEP) of CLL cells from lymph nodes (LN), bone marrow (BM), and peripheral blood (PB) are significantly different from each other. Among the major pathways associated with differential gene expression, a “tolerogenic signature” involved in host immune tolerance is significant in regulating CLL progression. The genes associated with the tolerogenic signature are significantly differentially expressed in patient LN-CLL compared to BM-CLL and PB-CLL, suggesting that LN-CLL cells induce this immune tolerance. From 83 differentially expressed genes identified by GEP that are associated with immune dysregulation, we selected eleven genes (CAV1, PTPN6, PKCb, ZWINT, IL2Ra, CBLC, CDC42, ZNF175, ZNF264, IL10, and HLA-G) for validation studies to determine whether these genes are also dysregulated in the Emu-TCL1 mouse model of CLL. The results demonstrate a trend of upregulation of these genes as determined by qRT-PCR in the LN-tumor microenvironment. To further evaluate the kinetics of selected gene expression during tumor progression, we determined the expression levels of Cav1, Ptpn6, and Pkcb at 12, 24, and 36 weeks of CLL development in the Em-TCL1 mouse model. We found that the expression of all three genes increased as a function of age, indicating a correlation of gene expression with disease progression. In addition, as CLL progressed in these mice there was a marked decrease in CD4+ and CD8+ T cells. The murine data were further validated using CLL cells from the same patients with indolent versus aggressive disease indicating a similar trend in expression as CLL progressed (n=4). Furthermore, patient data analyzed by Kaplan Meier analyses of the expression levels of the selected genes indicated a significant association between down-regulation of PTPN6 (p=0.031) and up-regulation of ZWINT (p<0.001) with clinical outcome as determined by a shorter time to treatment (p<0.05). Functional analysis by knockdown of CAV1 and PKCb in primary patient CLL cells determined by MTT assay showed a decrease in proliferation following knockdown of these genes (p<0.005). Protein-interaction modeling revealed regulation of CAV1 and PTPN6 by one another. Additionally, the PTPN6 protein regulates B cell receptor (BCR) signaling and subsequently the BCR regulates PKCb. Therefore, these data from both mice and humans with CLL, argue that an aggressive disease phenotype is paralleled by expression of genes associated with immune suppression. In particular, evidence presented here suggests, dysregulation of CAV1, PTPN6, ZWINT, and PKCb expression promotes CLL progression. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1656-1656
Author(s):  
Jana Volejnikova ◽  
Ester Mejstrikova ◽  
Karel Svojgr ◽  
Jan Stary ◽  
Jan Trka ◽  
...  

Abstract Abstract 1656 Introduction: Recently, Ikaros (IKZF1) gene alterations were found to predict poor prognosis in childhood acute lymphoblastic leukemia (ALL). Thus, the implementation of IKZF1 status into the risk group stratification is discussed. So far, limited data are available concerning both IKZF1 importance in different treatment protocols for Ph-negative ALL and the choice of the best diagnostic method. In this study, we compared two methods based on either genomic DNA examination or gene expression analysis, and their prognostic impact within a treatment protocol for childhood ALL. Methods: Gene expression of functional (IK1, IK2) and non-DNA binding (IK4, IK6, IK8) IKZF1 isoforms was semi-quantitatively evaluated using Lab-on-a-chip (Agilent) electrophoresis and reported either as an absolute level or relatively to the total isoform signal. The thresholds for abnormal gene expression were set based on the analysis of peripheral blood (PB) of healthy donors, remission bone marrow (BM) samples of children with ALL, and sorted B- and T-cell precursor subpopulations. MLPA (multiplex ligation-dependent probe amplification) reaction including probes for Ikaros exons 1 to 8 was performed on BM DNA samples and the products were analyzed with the Coffalyser v9.4 software. Results: Results of both gene expression and MLPA analysis in the BM were available for 120 of 193 children diagnosed with ALL between 2002 and 2005. MLPA analysis revealed a deletion of at least one exon of IKZF1 gene in 17/120 (14%) patients. Of note, two patients with this deletion underwent a lineage switch (LS) from ALL to AML during the induction treatment. The entire IKZF1 gene was mononoallelically deleted in 3 patients. The ratio between non-DNA binding (IK4, IK4del, IK4A, IK6, Ik6del, IK8) and functional (IK1 and IK2) isoform expression was significantly elevated (non-DNA binding isoforms>70%) in 21 of 120 (18%) patients. The expression of a dominant-negative IK6 isoform was significantly elevated (>20% of total) in 7 of 120 (6%) patients. Surprisingly, gene deletion on one allele was not accompanied by decrease of total IKZF1 gene expression. On the contrary, patients with IKZF1 deletion had higher total IKZF1 transcript level than those without deletion (p=0.008, Mann Whitney), but it was not possible to set any reliable expression threshold for the prediction of gene deletion. The change on a DNA level was not always reflected in relative gene expression: Of 17 patients with gene deletion, only 7 had significantly altered short/long isoform ratio and 5 patients had an increased expression of IK6. Conversely, of 7 patients with IK6 overexpression, two patients had no DNA alteration, suggesting a different mechanism of altered gene expression. We next evaluated the prognostic impact of IKZF1 alterations in 113 patients treated with ALL IC-BFM 2002 protocol (5 patients were excluded due to Ph-positive ALL with imatinib-based treatment and 2 patients due to treatment change after LS). Patients with IKZF1 gene deletion had significantly worse relapse-free survival (RFS) than other patients (5-year RFS 50.0±14.4% vs. 90.8±2.9%, p=0.0002). The presence of IKZF1 deletion did not correlate with minimal residual disease (MRD) during induction treatment (days 8, 15, 33), neither in BM nor in PB. Patients with IK6 overexpression had 5-year RFS 50.0±20.4% compared to 88.4± 3.2% in those with low IK6 expression (p=0.004). The elevated short/long isoform ratio (>70%) had no prognostic impact. The best prediction of relapse was achieved via combining two factors: the presence of IKZF1 deletion detected by MLPA or the relative IK6 overexpression (>50% of total isoform signal). The 5-year RFS was 50.0±13.4% for this group (14 pts, 7 relapses) compared to 91.6±2.8% for other patients (99 pts, 8 relapses, p<0.0001). Conclusion: This study confirmed that the presence of Ikaros gene alterations was connected with a high risk of relapse also in a BFM-based protocol for Ph-negative childhood ALL treatment. The deletion within IKZF1 locus did not necessarily correlate with an altered Ikaros gene expression. Ideally, both genomic and gene expression-based approach should be applied together for the evaluation of prognosis. However, if this is not possible, the examination of DNA changes by MLPA identifies more patients who subsequently relapse than the gene expression-based approach. Support: VZ MSM 0021620813, P301/10/1877, IGA NS/10472-3 Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2510-2510
Author(s):  
Fabiana Ostronoff ◽  
Megan Othus ◽  
Phoenix A. Ho ◽  
Stephen H. Petersdorf ◽  
Jeanne E. Anderson ◽  
...  

Abstract Abstract 2510 Background: KIT receptor tyrosine kinase mutations are recurrent genetic alteration found in acute myeloid leukemia (AML) with higher prevalence in those with core binding factor (CBF) AML. Different prognostic significance of these mutations has been found in pediatric and adult AML studies. However, prevalence and prognostic impact of KIT mutations in elderly patients with AML has not been established. In this study, we evaluated the prevalence of KIT mutation and its correlation with cytogenetic, molecular subtypes and clinical outcome in elderly AML patients. Methods: Diagnostic specimens from for 207 patients with AML registered on SWOG trials S-9031 and S-9333 were available for KIT mutation analysis. Both of these clinical protocols enrolled AML patients > 55 years. The samples were analyzed for the presence of KIT mutations via direct sequencing of exons 8 and 17. Results: In the cohort of 207 patients tested, the median age, WBC, and blast count at diagnosis were 68 years (range, 56–88 years), 29,6 × 109/L (range, 7–289 × 109/L) and 67% (0–99%), respectively. Favorable, intermediate and unfavorable cytogenetics were present in 8%, 57% and 26% of the patients, respectively. Nine percent of the patients had cytogenetics abnormalities of unknown significance. Normal cytogenetics was present in 48% of the patients. Fifty-three patients (26%) harbored mutations for FLT3-ITD, 37 (19%) for DNMT3A, 52 (31%) for NPM1 and 50 (24%) for IDH1/2. Only 3 patients were positive for CEBPA mutation. Of the 207 patient specimens tested, KIT exon 17 mutations were detected in 4 patients (2%). Exon 8 mutations were not identified. The characteristics of the 4 patients with KIT mutations are described in the table. Of the 4 patients who harbored the KIT mutation, 2 had intermediate, 1 had unfavorable risk cytogenetics and 1 patient did not have available cytogenetic data. None of the patients with CBF had KIT mutations. In terms of other molecular markers, all 4 patients were wild-type for NPM1, CEBPA, DNMT3A, IDH1/2 and FLT3-ITD. The very small number of KIT mutations in this group of patient precluded correlation between KIT mutations and clinical outcome. Conclusion: The prognostic impact of KIT mutations has been shown to vary according to cytogenetics subgroups. Most studies report a negative prognostic impact of these mutations in patients with CBF AML. The prognostic implications of KIT mutations also seem to vary among different age groups, with pediatric studies indicating they have no prognostic significance and adult studies indicating a negative prognostic impact. To date, there is no large study reporting on the incidence and prognostic impact of KIT mutations in elderly patients with AML. The very low incidence of KIT mutations in our study highlights the age-specific characteristics of AML and may correlate with lower prevalence of CBF translocations in older AML. Further studies investigating the relationship among different somatic mutations in elderly AML patients may help to clarify the pathogenetic mechanism of certain AML subtypes in this patient population. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3020-3020
Author(s):  
Alicia Báez ◽  
Beatriz Martin-Antonio ◽  
Concepción Prats-Martín ◽  
Isabel Álvarez-Laderas ◽  
María Victoria Barbado ◽  
...  

Abstract Abstract 3020 Introduction: Hematopoietic progenitors cells (HPCs) used in allogenic transplantation (allo-HSCT) may have different biological properties depending on their source of origin: mobilized peripheral blood (PB), bone marrow (BM) or umbilical cord (UC), which may be reflected in miRNAs or gene expression. The identification of different patterns of expression could have clinical implications. The aim of this study was to determine differences in miRNAs and gene expression patterns in the different sources of HPCs used in allo-HSCT. Materials and Method: CD34 + cells were isolated by immunomagnetic separation and sorting from 5 healthy donors per type of source: UC, BM and PB mobilized with G-CSF. A pool of samples from PB not mobilized was used as reference group. We analyzed the expression of 375 miRNAs using TaqMan MicroRNA Arrays Human v2.0 (Applied Biosystems), and gene expression using Whole Human Genome Oligo microarray kit 4×44K (Agilent). The expression levels of genes and miRNAs were obtained by the 2-ΔΔCTmethod. From expression data hierarchical clustering was performed using the Euclidean distance. To identify genes and miRNAs differentially expressed between the different sources of HPCs statistical Kruskal Wallis test was applied. All analysis were performed using the Multiexperiment Viewer 4.7.1. The function of the miRNAs and genes of interest was determined from the various databases available online (TAM database, Gene Ontology and TargetScan Human). Results: Forty-two miRNAs differentially expressed between the different sources were identified. As compared to BM or UC, in mobilized PB most miRNAs were overexpressed, including the miRNA family of miR515, which is characteristic of embryonic stem cells. On the other hand, 47 genes differentially expressed between the different sources were identified. Interestingly, a similar pattern of expression was observed between movilized PB and UC as compared to BM. Interestingly, 13 of these genes are targets of the miRNAs also identified in this study, which suggests that their expression might be regulated by these miRNAs. Conclusion: There are significant differences in miRNAs and gene expression levels between the different sources of HPCs Disclosures: No relevant conflicts of interest to declare.


Sign in / Sign up

Export Citation Format

Share Document