Methylation Status of the Collagen Prolyl-3 Hydroxylases (C-P3H) and C-P4H Genes in Multiple Myeloma: P3H2 Is Selectively Methylated

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4639-4639
Author(s):  
Eleftheria Hatzimichael ◽  
Aggeliki Dasoula ◽  
Konstantinos Lagos ◽  
Georgianna Kartalou ◽  
George Dranitsaris ◽  
...  

Abstract Abstract 4639 Background–Aim: Prolyl hydroxylation is an important and the most common post-translational modification that affects the structure and function of collagen. Enzymes that participate in this process are the collagen prolyl-3 hydroxylases (C-P3H) and the C-P4H. We have previously showed that P3H3 is methylated in multiple solid tumour types, whereas methylation in P3H2 appears to be specific for breast cancer and multiple myeloma (MM). In this study we assessed the CpG methylation status of the P3H genes (P3H1, P3H2, P3H3) in a larger cohort of MM patients and for the first time the CpG methylation status of the P4H genes (P4HA1, P4HA2, P4HA3) and investigated for clinical relevance. Patients and Methods: Bone marrow aspirate samples from 47 MM patients (28 males, median age 66 years) were obtained at diagnosis. Methylation-specific PCR (MSP) was employed to study the CpG methylation in P3H1, P3H2, P3H3, P4HA1, P4HA2 and P4HA3 CpG islands. Genomic DNA was isolated and bisulphite modified using commercially available kits (QIAmp DNA mini kit, Qiagen and EZ DNA methylation kit, Zymo Research respectively). Control methylated and unmethylated genomic DNAs were included in each experiment. For the study of the P3H2 CpG methylation status we used 2 sets of independent primers, which map to different areas of P3H2 CpG island. Ten bone marrow samples from patients with border line thrombocytopenia that were proved to have no neoplasia served as negative controls. Logistic regression analyses were used to measure the association between gene methylation and age, b2 microglobulin, serum albumin, hypercalcemia, ISS stage, extramedullary disease, bone disease, anemia and renal failure (eGFR< 50 ml/min). Results: None of the six genes under study was methylated in the control bone marrow samples. Methylation in the CpG island of P3H2 was detected in 44 % of patients (95% CI 27.8–62.8%) No methylation was detected in the CpG islands of P3H1, P3H3, P4HA1, P4HA2 and P4HA3. Trends noted were that patients with methylated P3H2 were more likely to have ISS stage 3 (OR 2.2, p=0.1). Overall no significant association was found with any clinical parameter although the study might have been underpowered due to the small population size. Conclusions: P3H2 is methylated at high frequency in MM, whereas P3H1, P3H3, P4HA1, P4HA2, P4HA3 were unmethylated, implying a striking specificity for methylation in P3H2 in MM. These findings warrant further evaluation in a larger sample of patients in order to better define the prognostic and clinical utility of P3H2 methylation in MM. Disclosures: No relevant conflicts of interest to declare.

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e19532-e19532
Author(s):  
A. Dasoula ◽  
E. Hatzimichael ◽  
G. Dranitsaris ◽  
L. Benetatos ◽  
N. Syed ◽  
...  

e19532 Background: We previously showed that polo like kinase 2 (Snk/Plk2) is subject to methylation-dependent transcriptional silencing in a very high frequency in Burkitt lymphomas. Here, we have examined CpG methylation in Snk/Plk2 in a well-characterized series of multiple myeloma (MM) patients. Methods: Bone marrow samples from individuals with MM were obtained at diagnosis and in 5 cases at disease progression as well. Genomic DNA was isolated and bisulphite modification was performed using commercially available kits. The methylation-specific polymerase chain reaction (MSP) was employed to study its methylation status. Control methylated and unmethylated genomic DNAs were included in each experiment. Ten bone marrow samples from individuals proven to have no haematological malignancy, served as negative controls. Logistic regression analyses were used to measure the association between gene methylation and the development of advanced disease (DS≥II), extramedullary disease, bone disease, anemia (Hb 10 mg/dl), serum albumin and beta 2 microglobulin levels. Results: We analyzed the methylation of Snk/Plk2 in 45 cases of MM (24 male, 21 female, mean age 66.4 years ±12.4). Classical cytogenetic analysis was available in 30/45 patients and none of them was found to have chromosome 13 abnormalities. No sample from the control population was found methylated. The Snk/Plk2 promoter was found to be methylated in 27/45 patients (60%). Median survival of patients in whom the Snk/Plk2 CpG island was methylated was 7.1 years compared to a median survival of 8.8 years for unmethylated. However Snk/Plk2 methylation was not a predictor of excess mortality (HR=0.6, p=0.5), bone lytic lesions (OR=0.56, p=0.3), anemia (OR=0.5, p=0.3) or advanced stage as defined above (OR=0.8, p=0.7). Conclusions: Snk/Plk2 DNA Methylation is a frequent event in patients with multiple myeloma. There was no association between the methylation status of the gene and relevant clinical parameters. Further evaluation in a larger sample of patients is needed in order to better define the prognostic and clinical value if any of Snk/Plk2 methylation in MM. No significant financial relationships to disclose.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2397-2397
Author(s):  
Eleftheria Hatzimichael ◽  
Aggeliki Dasoula ◽  
George Dranitsaris ◽  
Amalia Vassou ◽  
Justin Stebbing ◽  
...  

Abstract Abstract 2397 Poster Board II-374 Background-Aim: BIK (bcl2-interacting killer) is the founding member of the BH3-only family proapoptotic proteins and is implicated in the selection of B cells in humans. The expression of BIK in cancer is prevented by chromosomal deletions or by epigenetic silencing. On the other hand, BIK upregulation is induced by proteasome inhibitors such as bortezomib and MG132. Although it has been shown that BIK is a target of epigenetic silencing in the IL-6 dependent multiple myeloma cell line KAS-6/1, no studies exist regarding the CpG methylation status of BIK in primary tumors. We wished to examine the CpG methylation status of BIK in patients with multiple myeloma (MM). Patients and methods: Bone marrow aspirate samples from individuals with MM were obtained at diagnosis. Methylation-specific PCR (MSP) was employed to study methylation in the BIK CpG island. Genomic DNA was isolated and bisulphite modification performed using commercially available kits (QIAmp DNA mini kit, Qiagen and EZ DNA methylation kit, ZymoResearch respectively). Control methylated (CpG GenomeTM Universal Methylated, Chemicon International) and unmethylated genomic DNAs were included in each experiment. Ten bone marrow samples from individuals with borderline thrombocytopenia, that proved to have no haematological malignancy, served as negative controls. Logistic regression analyses were used to measure the association between gene methylation and age, ISS stage, ECOG performance status, extramedullary disease, bone disease, anemia (Hb 10 mg/dl), serum albumin and beta 2 microglobulin levels and relapsed/refractory disease. Results: Methylation in the BIK CpG island was studied in 40 MM patients (21 male, 19 female, mean age 66). ISS staging were as follows: stage I 14 patients (36%), II 12 patients (31%), III 12 patients (31%). Methylation of the BIK CpG island was founded in 16 patients (40%) and men were more likely to be methylated (OR=3.08, p=0.098). No correlation was found between BIK CpG methylation and age, ECOG performance status, ISS staging, anemia, beta 2 microglobulin levels, albumin levels, and overall survival. Patients methylated for BIK had a 2-fold tendency to have bone disease (p=0.35) and a 3-fold tendency to have extramedullary disease (p=0.14). Notable, patients with methylated BIK had a higher risk of relapsed/refractory disease (OR=5.4, p=0.033). Conclusions: To the best of our knowledge, this is the first demonstration of aberrant methylation in the BIK CpG island in MM patients. Interesting associations between BIK CpG methylation and some relevant clinical parameters in patients with MM were suggested by the data. Most importantly, BIK CpG methylation in this series of patients was found to be strongly associated with relapsed/refractory disease. These findings warrant further evaluation in a larger sample of patients in order to better define the prognostic and clinical utility of BIK methylation in MM. Patients with refractory/relapsed disease could possibly benefit from agents enhancing BIK expression. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3645-3645
Author(s):  
Eleftheria Hatzimichael ◽  
Evangelia Xirofotou ◽  
Aggeliki Dasoula ◽  
Cristiana Lo Nigro ◽  
Laura Lattanzio ◽  
...  

Abstract Abstract 3645 Background–Aim: Gene silencing is a major mechanism of tumour suppressor gene inactivation in neoplasia, including multiple myeloma (MM). Prolyl hydroxylation is an important post-translational modification that affects the structure and function of collagen. The human genome contains 3 prolyl 3 hydroxylases (P3H) which are closely related in structure and function: Leprecan (P3H1), Leprecan Like 1 (Leprel1, P3H2) and Leprecan Like 2 (Leprel2, P3H3). Leprel2 is methylated in multiple solid tumour types, whereas methylation in Leprel1 appears specific for breast cancer. Leprecan is not detectably methylated in any solid tumour we have analysed. Here, we examine the CpG methylation status of the P3H genes in patients with MM. Patients and Methods: Bone marrow aspirate samples from 38 MM patients (22 males, 16 females) were obtained at diagnosis. Methylation-specific PCR (MSP) was employed to study methylation in the Leprel 1, Leprel2 and Leprecan CpG islands. Genomic DNA was isolated and bisulphite modification performed using commercially available kits (QIAmp DNA mini kit, Qiagen and EZ DNA methylation kit, Zymo Research respectively). Control methylated and unmethylated genomic DNAs were included in each experiment. We used 2 sets of independent primers, which map to different areas of the leprel 1(P3H2) CpG island. Pyrosequencing is ongoing to confirm the sensitivity and specificity of MSP for analysis of P3H gene methylation in our study population. Ten bone marrow samples from patients with border line thrombocytopenia that were proved to have no neoplasia served as negative controls. Logistic regression analyses were used to measure the association between gene methylation and age, ISS stage, extramedullary disease, bone disease, anemia, renal failure, multiple treatments and relapsed/refractory disease. Results: None of the three genes under study was methylated in the control bone marrow samples, but methylation in the CpG island of Leprel 1 was detected in 20 cases (52%). No methylation was detected in the CpG islands of Leprel2 or Leprecan. Trends noted were that patients with methylated leprel 1 were more likely to have ISS stage 3 (OR 1.5, p=0.6), to have received multiple treatments (OR=1.7, p=0.4) and to have received radiotherapy for either bone lytic lesions or extramedullary disease (OR=5.6, p=0.1). Overall no significant association was found with any clinical parameter although the study might have been underpowered due to the small population size. Conclusions: This is the first demonstration of methylation of genes encoding collagen, the prolyl hydroxylases in MM, suggesting that this may be a novel class of myeloma suppressors. Interestingly, Leprel1 was methylated at high frequency, whereas Leprecan and Leprel2 were unmethylated, implying a striking specificity in MM for methylation in Leprel1. These findings warrant further evaluation in a larger sample of patients in order to better define the prognostic and clinical utility of leprel1 methylation in MM. Disclosures: No relevant conflicts of interest to declare.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e19537-e19537
Author(s):  
E. Hatzimichael ◽  
A. Dasoula ◽  
J. Stebbing ◽  
G. Dranitsaris ◽  
T. Crook ◽  
...  

e19537 Background: Multiple myeloma (MM) is an incurable interleukin (IL)-6 dependent plasma-cell malignancy. Transforming growth factor-β (TGF-β) is the major inducer of IL-6 secretion by bone marrow stromal cells. The signaling responses to TGF-b are mediated by the Smad proteins. The Smurf2 gene (Smad ubiqitiniation regulatory factor 2) encodes a Smad-specific E3 ubiquitin ligase and targets Smad2 and Smad3 for proteasome-dependent degradation. Methods: Bone marrow samples from individuals with MM were obtained at diagnosis and in 5 cases at disease progression as well. Genomic DNA was isolated and bisulphite modification was performed using commercially available kits. The methylation-specific polymerase chain reaction was employed to study the methylation status of the CpG island. Logistic regression analysis was used to measure the association between gene methylation and the development of advanced disease (DS≥ II), extramedullary disease, bone disease, anemia (Hb 10 mg/dl), serum albumin and beta 2 microglobulin levels. Results: We analysed the methylation of Smurf2 in 45 cases of MM (24 male, 21 female, mean age 66.4 years). No sample from the control population was found methylated. The Smurf2 gene promoter was found to be methylated in 11/45 MM patients (24%). Interesting trends were noted where patients with methylated Smurf2 promoter had an increased risk of death (HR = 1.3; p = 0.68), anemia (OR=2.1, p=0.2) and advanced stage (OR=1.3, p=0.6) and a reduced risk of extramedullary disease (OR= 0.2, p=0.2). No association was found between Smurf2 methylation status and bone lytic lesions, serum albumin levels or beta-2 microglobulin levels. Conclusions: Interesting associations between Smurf2 methylation and some relevant clinical parameters in patients with MM were suggested by the data. These findings warrant further evaluation in a larger sample of patients in order to enhance our statistical power and better define the prognostic and clinical value of Smurf2 methylation in MM. No significant financial relationships to disclose.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4421-4421
Author(s):  
Wei-Xin Hu ◽  
Qiang Qu ◽  
Jiang Li ◽  
Wei Ren

Abstract Abstract 4421 Most malignant features of cancer cells are triggered by activated oncogenes and the loss of tumor suppressors due to mutation or epigenetic inactivation. We previously reported that DAZAP2 was down-regulated in newly diagnosed myeloma (MM) and this may influence MM cell growth and survival. This study was undertaken to evaluate the mechanism of down-regulation DAZAP2 and determine the methylation status and loci of its promoter by using bisulphite genomic-sequencing (BGS) method in KM3 myeloma cell line. Two islands with rich GC box in the promoter of DAZAP2 gene were identified and amplified by using bisulfite-sequencing PCR (BSP). Island 1 spans -472 to -247 including 9 CpG sites (CpGs) and island 2 covers -226 to -13 including 23 CpG sites. The ratio of methylated CpGs in two CpG islands was 46.25%. The above sequences were demethylated and inserted into a pGL2-basic vector. COS-7 cells were transfected with recombinant plasmids and the activity of luciferase was evaluated. The results showed that the CpG island 1 had a weakly transcriptional activity, whereas the CpG island 2 had a strong transcriptional activity (2.38 folds compared with the positive control). The other sequence which covered CpG island 1 and 2 showed a remarkable activity (15.1 folds compared with the positive control). These data indicated that CpG island 2 of DAZAP2 gene may be hypermethylated and suppressed its expression in MM cells. We further correlated DAZAP2 expression with normal plasma cells and malignant myeloma cells, as well as the molecular subtypes which the dataset includes 8 genetic subtypes (MY, PR, LB, MS, HP, CD-1, CD-2, and MF) from 351 newly diagnosed myeloma cases (Zhan, 2006). Interestingly, we extended and confirmed our previous discovery that DAZAP2 was significantly down-regulated in MM cells by using a large uniform dataset (P = 0.004). The low expression of DAZAP2 was especially significant in the subgroups of MY, PR, LB, HP, and CD-1. This study warrants further investigation of DAZAP2 and its potential role in myeloma. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4640-4640
Author(s):  
Eleftheria Hatzimichael ◽  
Aggeliki Dasoula ◽  
Nelofer Syed ◽  
Peter Szlosarek ◽  
George Dranitsaris ◽  
...  

Abstract Abstract 4640 Background. Arginine is critical for the growth of certain human cancers and is an intermediary in the synthesis of various bioactive molecules. Argininosuccinate synthetase-1 (ASS1) catalyses the rate-limiting step in arginine biosynthesis, the conversion of citruline to arginine. Argininosuccinate lyase (ASL) is an enzyme that catalyses the reversible breakdown of arginosuccinate producing arginine and fumerate. Down-regulation of ASS1 has been demonstrated in several solid cancers and has been shown to confer sensitivity to arginine deprivation (arginine auxotrophic tumors). Methylation-dependent silencing of the ASS1 promoter may account for ASS1 down-regulation and arginine auxotrophy. Arginine deprivation using arginine deiminase (ADI-PEG20) is currently considered as a novel therapeutic intervention for cancer, and early clinical trials have shown promising results in solid tumors. In this perspective, we investigated for the first time the methylation status of the ASS1 and ASL CpG islands in multiple myeloma (MM) and analyzed for clinical relevance. Methods. Genomic DNA was extracted from bone marrow aspirate samples from 46 MM patients (28 male, 18 female, median age 64 years) obtained at diagnosis. Methylation-specific PCR (MSP) was employed to study the methylation in the ASS1 and ASL CpG islands. DNA was isolated and bisulphite modified using commercially available kits (QIAmp DNA mini kit, Qiagen and EZ DNA methylation kit, Zymo Research respectively). Control methylated and unmethylated genomic DNAs were included in each experiment. Ten bone marrow samples, with no neoplastic cells, from patients with borderline thrombocytopenia served as negative controls. Logistic regression analysis was used to measure the association between gene methylation and sex, age, ISS stage, presence of extramedullary disease, renal failure (eGFR<50 ml/min) and bone disease. Results. Methylation in the CpG island of ASS1 was detected in 71.7% patients (95% CI 57–82%) and of ASL in 37% patients (95% CI 24–51%), while simultaneous methylation in both genes was present in 10 patients. None of the two genes were detectably methylated in the control group. Patients with ASS1 methylation were less likely to have bone disease (p=0.04, OR=0.22) and extramedullary disease (p=0.05, OR=0.22). There was no statistically significant difference in overall survival by methylation status of the studied genes. Conclusions. Arginine biosynthesis genes ASS1 and ASL are methylated in MM. Methylation of ASS1 was found to be more frequent and negatively associated with bone or extramedullary disease. Further evaluation of ASS1 and ASL methylation is warranted in MM in the perspective of expanding arginine deprivation trials in these patients Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3144-3144
Author(s):  
Yu Qin ◽  
Fei Li ◽  
Gang An ◽  
Mu Hao ◽  
Meirong Zang ◽  
...  

Abstract Background MicroRNAs are non-coding small RNAs that modulate protein expression and are implicated in the pathogenesis of much kind of cancers. miR-137 was reported to act as a tumor suppressor in different cancers. In the present study, we describe the epigenetic regulation of miR-137 and its contribution in Multiple Myeloma (MM). Methods and Results Real-time RT-PCR was used to screen the expression levels of miR-137 in MM cell lines and CD138+ cell sorted from MM patients, which confirmed the downregulation of miR-137 in MM cell lines and patients, and the expression of cell lines increasing treated with epigenetic drugs 5-aza-dC. The methylation status of miR-137 CpG island was determined by bisulfite pyrosequencing and methylation specific polymerase chain reaction (MSP). Methylation of the miR-137 CpG island was frequently observed in MM cell lines and patients but not in healthy donor and MGUS. Cck-8 assay showed transfection of miR-137 precursor in MM cells significantly inhibited cell proliferation and increased cell drug sensitivity. Importantly, Ectopic expression of miR-137 in MM cells inhibited phosphorylation of mitogen-activated protein kinase (MAPK/ERK). To further identify miR-137 targets, we used bioinformatics analysis and confirmed using a luciferase reporter assay. To validate AURKA as miR-137 target, we cloned the 3' UTR sequence of human AURKA into the luciferase-expressing vector psiCHECK. 293Tcells were transiently transfected with this construct in the presence of pre-miR-137 or a scrambled oligonucleotide acting as a negative control. As reported in luciferase plate reader, miR-137 significantly reduced luciferase activity compared with the scrambled control miRNA. This indicated that miR-137 binds to the 3'UTR of AURKA and impairs its mRNA translation. Furthermore, NCI-H929 cells were transfected with AURKA shRNA vector psiHIV-mH1-AURK and westernblot showed phosphorylation of ERK was also significantly decreased. Conclusion miR-137 was epigenetic Silenced and targeted AURKA expression to contribute to the proliferation through MAPK/ERK pathway in MM. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4479-4479
Author(s):  
Eleftheria Hatzimichael ◽  
George Dranitsaris ◽  
Aggeliki Dasoula ◽  
Nelofer Syed ◽  
Justin Stebbing ◽  
...  

Abstract Background-Aim: The polo like kinases (Plk) are highly conserved in evolution and have critical functions in the regulation of proliferation and cell cycle checkpoints. We previously showed that polo like kinase 2 (Snk/Plk2) is subject to methylation-dependent transcriptional silencing in B lymphomas, with a very high frequency in Burkitt lymphomas, implying that Snk/Plk2 may have a tumour suppressor function in B lymphocytes. However, no study has examined epigenetic changes in plasma cell dyscrasias. Here, we have examined CpG methylation in Snk/Plk2 in a well-characterised series of multiple myeloma (MM) patients. Patients and Methods: Bone marrow samples from individuals with MM were obtained at diagnosis and disease progression. Genomic DNA was isolated and bisulphite modification was performed using commercially available kits (QIAmp DNA mini kit, Qiagen and EZ DNA methylation kit, Zymo Research respectively). The methylation-specific polymerase chain reaction (MSP) with primers for methylated and unmethylated alleles of the Snk/Plk2 gene promoter was employed to study its methylation status. Control methylated (CpG Genome™ Universal Methylated, Chemicon International) and unmethylated genomic DNAs were included in each experiment. Ten bone marrow samples from individuals with borderline thrombocytopenia, that proved to have no haematological malignancy, served as negative controls. Survival curves were generated using the method of Kaplan-Meier and compared with the log-rank test. Logistic regression analyses were also used to measure the association between gene methylation and the development of advanced disease (DS³II), extramedullary disease, bone disease, anemia (Hb≤10 mg/dl), serum albumin and beta 2 microglobulin levels. Results: We analysed the methylation of Snk/Plk2 in 45 cases of multiple myeloma (MM) (24 male, 21 female, mean age 66.4 years ±12.4). Using the Durie and Salmon staging system MM patients’ disease stages were as follows: smoldering MM 7/45, IA 9/45, IIA 13/45 patients, IIIA 7/45 patients and IIIB 9/45 patients. Classical cytogenetic analysis was available in 30/45 patients and none of them was found to have chromosome 13 abnormalities. No sample from the control population was found methylated. The Snk/Plk2 promoter was found to be methylated in 27/45 (60%) MM patients. Median survival of patients in whom the Snk/Plk2 CpG island was methylated was 7.1 years compared to a median survival of 8.8 years for unmethylated. However Snk/Plk2 methylation was not a predictor of excess mortality (HR=0.6, p=0.5), bone lytic lesions (OR=0.56, p=0.3), anemia (OR=0.5, p=0.3) or advanced stage as defined above (OR=0.8, p=0.7). A trend was noted where patients with methylated Snk/Plk2 had a reduced risk of developing extramedullary disease (OR=0.3, p=0.1). No association was found between the methylation and serum albumin (p=0.3) or beta 2 microglobulin levels (p=0.8). Conlusions: We examined for the first time the methylation status of Snk/Plk2 in MM patients and showed that it is a common event in these patients implying that loss of function in this gene is frequently involved in the pathogenesis of MM. However there was lack of association between the methylation status of the gene and relevant clinical parameters. Further evaluation in a larger sample of patients is needed in order to better define the prognostic and clinical value if any of Snk/Plk2 methylation in MM.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e18567-e18567
Author(s):  
Eleftheria Hatzimichael ◽  
Aggeliki Dasoula ◽  
Nelofer Syed ◽  
Peter Wojciech Szlosarek ◽  
George Dranitsaris ◽  
...  

e18567 Background: Argininoosuccinate synthetase-1 (ASS1) catalyses the rate-limiting step in arginine biosynthesis, the conversion of citruline to arginine. Argininosuccinate lyase (ASL) is an enzyme that catalyses the reversible breakdown of arginosuccinate producing arginine and fumerate. Arginine deprivation using arginine deiminase (ADI-PEG20) is currently considered as a novel therapeutic intervention for cancer. In this perspective, we investigated the methylation status of the ASS1 and ASL CpG islands in multiple myeloma (MM) and analyzed for clinical relevance. Methods: Genomic DNA was extracted from bone marrow aspirate samples from 46 MM patients (28 male, 18 female, median age 64 years) obtained at diagnosis. Methylation-specific PCR was employed to study the methylation in the ASS1 and ASL CpG islands. DNA was isolated and bisulphite modified using commercially available kits. Logistic regression analyses were used to measure the association between gene methylation and sex, age>65, ISS stage, presence of extramedullary disease, renal failure and bone disease. Kaplan-Meier curves were used to estimate the probabilities of survival and the Log-rank test to assess the statistical significance of differences in event rates. Results: Methylation in the CpG island of ASS1 was detected in 71.7% patients and of ASL in 37% patients, while simultaneous methylation in both genes was present in 10 patients. None of the two genes was detectably methylated in the control group. Patients with ASS1 methylation were less likely to have bone disease (p=0.04, OR=0.22) and extramedullary disease (p=0.05, OR=0.22) and a trend was also noted that these patients were less likely to be >65 years of age (p=0.2, OR=0.37). We did not detect any statistically significant difference in overall survival by methylation status of the studied genes in this small study size. Conclusions: We demonstrate for the first time that arginine biosynthesis genes ASS1 and ASL are methylated in MM.Methylation of ASS1 was found to be more frequent and negatively associated with bone or extramedullary disease. Further evaluation of ASS1 and ASL is warranted in MM and supports the expansion of arginine deprivation trials in these patients


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Hikaru Takano ◽  
Tomoyuki Shibata ◽  
Masakatsu Nakamura ◽  
Naoko Sakurai ◽  
Tasuku Hayashi ◽  
...  

Abstract Background CpG methylation of tumor suppressor genes occurs in the early stage of carcinogenesis. Detecting risk factors for aberrant CpG methylation is clinically important for predicting cancer development. DNA methyltransferase (DNMT) 3a is considered to play critical roles in the DNA methylation process during pathogenesis. In this study, we evaluated the association between DNMT3A polymorphisms (rs6733868 and rs13428812) and CpG methylation status in non-cancerous gastric mucosa. Methods We determined the DNMT3A genotype and CpG methylation status of 4 genes (p14ARF, p16INK4a, DAPK, and CDH1) in 510 subjects without gastric cancer. Helicobacter pylori (HP) infection status was determined by the rapid urease test, urea breath test, speculum examination, or serum antibody test. We determined the DNMT3A genotype using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP). CpG methylation status was determined by methylation-specific polymerase chain reaction (MSP). When the methylated band was stronger than 10 ng/μL according to the DNA marker, we judged CpG island hypermethylation (CIHM) to be present. Associations between genotypes and susceptibilities were assessed by logistic regression analysis. Results The minor allele frequencies of both polymorphisms (rs6733868 and rs13428812) were lower in the CpG methylated groups of each of the 4 genes (p14ARF, p16INK4a, DAPK, and CDH1). Using a dominant genetic model, rs6733868 was significantly associated with the hypermethylation of each gene, whereas rs13428812 was associated with the methylation of 3 genes (all except p14ARF). When low-CIHM was defined as 1 or 2 CpG islands methylated and high-CIHM was defined as 3 or more CpG islands methylated, carrying the minor allele of rs6733868 was associated with both decreased low- and high-CIHM, and that of rs13428812 also was associated with a decrease. Comparing low-CIHM with high-CIHM, carrying the minor alleles of rs6733868 or rs13428812 was related to decreased susceptibility to high-CIHM. In HP-infected subjects, carrying the minor alleles of rs6733868 or rs13428812 had a significantly greater association with decreased susceptibility to high-CIHM. Conclusions Our study indicates that polymorphisms of DNMT3A are associated with the accumulation of gene methylation in gastric mucosa. Carrying the minor alleles of rs6733868 or rs13428812 inhibits aberrant gene methylations, which are typically enhanced by HP infection.


Sign in / Sign up

Export Citation Format

Share Document