Association Between Genetic Polymorphism in DNA Repair Genes and Acute Myeloid Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4131-4131
Author(s):  
Hee Nam Kim ◽  
Nan young Kim ◽  
Li Yu ◽  
Huong Thi Thanh Tran ◽  
Yeo-Kyeoung Kim ◽  
...  

Abstract Abstract 4131 Genetic variants in DNA repair genes may affect DNA repair capacity and modulate cancer susceptibility. We analyzed genetic polymorphisms of 11 DNA repair genes: XRCC4, BRCA1, WRN, RAD51, XRCC3, ERCC1, ERCC2, XPC, OGG1, XRCC1 and MGMT to evaluate the association and risk of acute myeloid leukemia (AML). A large-scale population-based, case-control study of 1700 controls and 659 cases was conducted in Chonnam National University Hwasun Hospital, Korea. Three single-nucleotide polymorphisms(SNPs), ERCC1 IVS5 +33 CC, WRN 787 GG and XRCC1 399 GA genotypes were associated with decreased risk for AML [odds ratio (OR) = 0.71; 95% confidence interval (CI) = 0.54-0.92, p=0.01 for IVS5 +33 CC, 0.67; 0.50–0.89, p=0.006 for 3149 GG and 0.81; 0.67–0.98, p=0.031 for 1316 GA]. We found no differences in the XRCC4 S307, BRCA1 P87L, RAD51 –G135C, XRCC3 T241M, ERCC2 K751Q, XPC K939Q, OGG1 S326C and MGMT L84F genotypes. Our results suggest that these 3 SNPs in DNA repair genes may affect AML susceptibility by modulating activities to maintain the genome integrity of each individual. Disclosures: No relevant conflicts of interest to declare.

2010 ◽  
Vol 128 (1) ◽  
pp. 233-238 ◽  
Author(s):  
Jing-Yi Shi ◽  
Zhi-Hong Ren ◽  
Bo Jiao ◽  
Run Xiao ◽  
Hai-Yang Yun ◽  
...  

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3456-3456 ◽  
Author(s):  
Ming-Yu Yang ◽  
Jan-Gowth Chang ◽  
Pai-Mei Lin ◽  
Jui-Feng Hsu ◽  
Cheng-Han Wu ◽  
...  

Abstract Abstract 3456 Studies in large-scale genome sequencing have shown that only 2% of the mammalian genome encodes mRNAs, but the most part is transcribed as long and short non-coding RNAs (ncRNAs). The ncRNAs with gene regulatory functions are starting to be seen as a common feature of mammalian gene regulation. Genomic imprinting is a form of epigenetic regulation and imprinted genes are silenced in a parental-specific manner. Imprinted genes tend to occur in clusters and ncRNAs have been found at all well-characterized imprinted clusters. Although the exact mechanism how imprinted ncRNA regulates gene expression remains largely unknown, it is general accepted that imprinted ncRNAs binds to chromatin modifying complexes, such as PRC2, TRX, and G9a, and generates specific silencing of genomic loci both in cis and trans. Imprinting is associated with many human diseases or syndromes (e.g. Prader-Willi, Angelman, Beckwith-Wiedemann, Retts, and Silver-Russell syndromes) and various cancers (e.g. breast, prostate, and colorectal cancers), but its role in leukemogenesis remain elusive. In this present study, a panel of 24 human imprinted ncRNAs genes, including ampd3, cpa4, snuf, rasgrf1, slc22a3, lgf2, treb3c, gabrb3, c15orf2, sfmbt2, rtl1, copg2, h19, l3mbtl, ppp1r9a, tspan32, lnpp5f, impact, nr3251, nr3252, znf215, prim2, peg3as and znf264, has been mined using Bioinformatics approach. We investigated the expression of these imprinted ncRNA genes using real-time quantitative RT-PCR in 67 newly-diagnosed acute myeloid leukemia patients with normal karyotypes (AML-NK), 22 AML patients with abnormal karyotypes (AML-AK), and 39 healthy individuals. In AML-NK patients, the expression of lgf2, h19, slc22a3, copg2, and impact were significantly upregulated than in healthy individuals (p < 0.0001). In AML-AK patients, besides lgf2, h19 and impact genes, ampd3 and gabrb3 were also significantly upregulated than in healthy individuals (p < 0.0001). Expression of igf2 was almost undetectable in healthy individuals but drastically increased in all AML patients. Both lgf2 and h19 were significantly increased in both AML-NK and AML-AK patients. From our preliminary results, it is reasonable to hypothesize that loss imprinting of lgf2/h19 is critical for the leukemogenesis of AML and under NK or AK conditions different additional ncRNAs are activated and affect different imprinted gene expression and thus leading to different clinical outcomes. Based on our findings, we will further perform methylation analysis of promoter CpG sites in AML patients to investigate if hypomethylation is responsible for the upregulation of these imprinted ncRNAs. We will also carry out in vitro functional analysis to elucidate the functions and mechanisms of these imprinted ncRNAs in AML tumorigenesis. Updated results of these analysis will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2605-2605
Author(s):  
Ming-Yu Yang ◽  
Jan-Gowth Chang ◽  
I-Ya Chen ◽  
Pai-Mei Lin ◽  
Hui-Hua Hsiao ◽  
...  

Abstract Studies in large-scale genome sequencing have shown that only 2% of the mammalian genome encodes mRNAs, but the most part is transcribed as long and short non-coding RNAs (ncRNAs). The ncRNAs with gene regulatory functions are starting to be seen as a common feature of mammalian gene regulation. Genomic imprinting is a form of epigenetic regulation and imprinted genes are silenced in a parental-specific manner. Although the exact mechanism how imprinted ncRNA regulates gene expression remains largely unknown, it is general accepted that imprinted ncRNAs binds to chromatin modifying complexes, such as PRC2, TRX, and G9a, and generates specific silencing of genomic loci both in cis and trans. Imprinting is associated with many human diseases or syndromes (e.g. Prader-Willi, Angelman, Beckwith-Wiedemann, Retts, and Silver-Russell syndromes) and various cancers (e.g. breast, prostate, and colorectal cancers), but its role in leukemogenesis remain elusive. In this present study, the expression of a panel of 24 human imprinted ncRNA genes (AMPD3, C15orf2, COPG2, CPA4, GABRB3, H19, IGF2, IMPACT, INPP5F, L3MBTL, NR3251, NR3252, PEG3-AS, PPP1R9A, PRIM2, RASGRF1, RTL1, SFMBT2, SLC22A3, SNURF, TCEB3C, TSPAN32, ZNF215, ZNF264) and a panel of 66 human histone modifying enzymes (HME) genes was investigated in 68 newly-diagnosed acute myeloid leukemia patients with chromosome normal (AML-CN), 115 AML patients with chromosome abnormal (AML-CA), and 85 healthy individuals using real-time quantitative RT-PCR. Altered expression of 9 imprinted ncRNA genes (C15orf2, COPG2, H19, IGF2, IMPACT, PEG3-AS, PRIM2, SLC22A3, ZNF215) and 16 HME genes were observed. In AML-CN, patients’ survival days are correlated with the expression levels of H19 (p < 0.01), IMPACT (p < 0.05), DNMT3L (p < 0.05) and AURORA (p < 0.01). In AML-CA, patients’ survival days are correlated with the expression levels of PGE3-AS (p < 0.01), PRIM2 (p < 0.01), SLC22A3 (p < 0.05), and ZNF215 (p < 0.01). Multiple linear regression analysis further revealed the expression level of H19 and ZNF215 can be used as predictors for 2-year survival for AML-CN patients (p = 0.002) and AML-CA patients (p = 0.040), respectively. Cox proportional hazard model was used to analyze the hazard ratio (HR) for H19 (HR=0.868, 95.0% Confident Interval: 0.797-0.945, p = 0.001) and ZNF215 (HR=0.904, 95.0% Confident Interval: 0.821-0.995, p =0.040). In addition to survival, analysis has also been performed to correlate patients’ clinical parameters and expression levels of these altered genes and to correlate the expression levels between imprinted ncRNA genes and HME genes (results will be presented at the meeting). From our preliminary results, it is reasonable to hypothesize that loss imprinting of imprinted ncRNA is critical for the leukemogenesis of AML and under CN or CA conditions different ncRNAs are activated and affect different imprinted gene expression and thus leading to different clinical outcomes. Based on our findings, we will further perform in vitro functional analysis to elucidate the functions and mechanisms of these imprinted ncRNAs in AML tumorigenesis. Updated results of these analyzes will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3916-3918 ◽  
Author(s):  
Mays Jawad ◽  
Claire Helen Seedhouse ◽  
Nigel Russell ◽  
Mark Plumb

AbstractStudies of radiation-induced acute myeloid leukemia (AML) in mice suggest that the number of target stem cells is a risk factor, and the HLX1 homeobox gene, which is important for hematopoietic development, is a candidate gene. The distribution of the C/T-3′ untranslated region (UTR) polymorphism in HLX1 in patients with AML and therapy-related AML (t-AML) compared with controls was therefore determined. The presence of the variant HLX1 allele significantly increases the risk of t-AML (OR = 3.36, 95% CI, 1.65-6.84). The DNA repair gene RAD51 (135G/C-5′ UTR) polymorphism also increases t-AML risk, and when combined analysis was performed on both RAD51 and HLX1 variant alleles, a synergistic 9.5-fold increase (95% CI, 2.22-40.64) in the risk of t-AML was observed. We suggest that the HLX1 polymorphism has an effect on stem cell numbers, whereas an increased DNA repair capacity (RAD51) will suppress apoptosis, a genetic interaction that may increase the number of genomes at risk during cancer therapy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5076-5076
Author(s):  
Sugunakar Vuree ◽  
Anuradha Cingeetham ◽  
Dunna Nageswara Rao ◽  
Manjula Gorre ◽  
Sudha Sinha ◽  
...  

Purpose of the study: Deregulated DNA repair is one of the hallmarks of cancers including Acute Myeloid Leukemia (AML), as it results in genomic instability. ATM gene functions as a sensor, activates cascade of events leading to stimulation of multiple DNA damage- responsive signaling pathways. Principal DNA repair mechanism activated in the hematopoietic stem cells is the Non Homologous End Joining (NHEJ) pathway. However, this pathway was shown to be error prone. Functional SNPs in the genes involved in DNA repair might influence the gene expression leading to altered DNA repair which might confer the risk to AML. Materials & Methods: This hospital-based case-control study included 225 AML patients and 326 cancer-free controls from South Indian population. Six polymorphisms of XRCC5, XRCC6, XRCC7 and ATM were genotyped using polymerase chain reaction (PCR)-Restriction Fragment Length Polymorphism (PCR- RFLP) method. Statistical analyses were performed by using SPSS (version20v) and SNPSTAT online tool. Protein-Protein Interaction (PPI) analysis was also done to see the relationship between these genes. Results: We found that there was an elevated risk of AML associated with the XRCC5 VNTR 0R repeat and A allele of 2408G>A polymorphism (p-0.04 and p<0.0001 respectively), the frequencies of G allele (p-<0.0001) of XRCC6 -1310C>G and T allele (p-0.003) of ATM -5144A>T polymorphisms were also significantly increased in AML cases. Further, analyses of the variant genotypes with epidemiological and clinical variables revealed a significant association of the risk genotypes with development and progression of AML. Conclusion: The XRCC5 0R repeat, 2408G>A, XRCC6 -1310 C>G and ATM- 5144A>T polymorphisms, but not XRCC6 -61C>G and XRCC7 6721G>T polymorphisms, play an important role in the pathogenesis of AML. Figure Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2951-2951
Author(s):  
Raoul Tibes ◽  
Ashish Choudhary ◽  
Amanda Henrichs ◽  
Sadia Guled ◽  
Irma Monzon ◽  
...  

Abstract In order to improve treatment strategies for Acute Myeloid Leukemia (AML), we adapted a functional genomics approach using RNAi screening to identify molecular targets that are vital to the growth of AML. Herein we report the first large-scale kinome gene silencing screen in AML. A high throughput RNAi screen was developed for the efficient siRNA transfection of AML cell lines. Eight commercially available cationic lipid-based transfection reagents were tested for their ability to transfect several AML cell lines with siRNA. These extensive transfection optimization experiments identified two AML cells lines TF-1 and ML4 with up to 95–100 and 70–75% transfection efficiency respectively. Two independent replicate kinome screens were performed on both cell lines using a siRNA library targeting 572 kinase genes with 2 siRNA/gene. At 96 hours post transfection, cell proliferation was assessed and the B-score method was used to background correct and analyze the screening data. Several siRNA to specific kinases were identified that significantly inhibit cell proliferation of up to ~40–88%. Hits were defined at two thresholds: siRNA having a B-score of &lt;−2 providing a statistically significance of p&lt;0.05 (confidence of &gt; 95%) and a cutoff B-score of &lt;−1.5 providing greater than 87% confidence for each siRNA hit. Two different kinases (2 siRNA/gene/screen) were identified as major growth regulating kinases in TF1 cells with all 4 siRNA/gene having a B-score &lt;−2. For two additional kinases, 3/4 siRNA for each gene had a Bscore &lt;−2. Expanding the cutoff to a B-score &lt;−1.5 three further kinases were targeted by at least 3/4 siRNA/gene. Similar analysis using the same criteria for ML4 cells identified one kinase targeted by 3/4 siRNA at a B-score &lt;−2, seven kinases with 2/4 siRNA &lt;−2 and two kinases with 3/4 siRNA/gene at a B-score of &lt;−1.5. Common hits for both cell lines with at least 6/8 siRNA per gene from 4 screens performing at a B-score &lt;−2 identified two kinases, one of them PLK1. Applying a B-score threshold of &lt;−1.5, we identified five kinases for which at least 5/8 siRNA/gene from 4 screens met these criteria. Kinases/genes will be presented at the meeting.Confirmation of gene silencing and validation of growth response is currently underway for a subset of genes. Among the strongest hits are siRNA targeting PLK1, as well as siRNA targeting three other kinase-genes involved in regulating cell cycle progression and checkpoints and gene ontology (GO) analysis showed enrichment in cell cycle and cell cycle-checkpoint processes. Inhibitors against PLK1 and other kinase hits identified in the screen are in (pre)-clinical development and if confirmed, our experiments provide a strong rational to test these in AML. The application of RNAi based screening is useful in the identification of genes important in AML proliferation, which could serve as targets for therapeutic intervention and guide AML drug development. Furthermore, results from these types of functional genomics approaches hold promise to be rapidly translated into clinical application.


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