Silencing of TESTIN by dense biallelic promoter methylation is the most common molecular event in childhood acute lymphoblastic leukaemia

The value of lung function assessment and Testin expression detection in clinicopathological features and prognosis of NSCLC patients

OBJECTIVE

The aim of this study is to investigate the clinical value and potential prognostic significance of lung function assessment and Testin expression in non-small cell lung cancer (NSCLC) patients.

METHODS

The NSCLC patients were classified into three groups according to lung function: group of normal lung function, group of PRISm (preserved ratio impaired spirometry) (FEV1, forced expiratory volume during the first second < 80% predicted and FEV1/FVC (forced vital capacity) ≥ 70%) and group of COPD (chronic obstructive pulmonary disease) (FEV1/FVC < 70%). The pre-operational clinicopathological characteristics of these patients were recorded and the markers of systemic inflammatory response, including neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), platelet to lymphocyte ratio (PLR) and eosinophils (EOS), were compared between three groups. The expression of Testin in NSCLC samples was detected by IHC and we further explored the correlation between Testin expression and clinicopathological characteristics and prognosis of NSCLC patients. Finally, Cox regression analysis was conducted to study the prognostic factors of NSCLC patients.

RESULTS

Of the 158 NSCLC patients, percentages of normal lung function, PRISm and COPD were 41.4%, 22.8% and 36.1%, respectively. Patients with tumor in the left lung were more likely to have pulmonary dysfunction (PRISm and COPD) than the right lung. The markers of systemic inflammatory response showed differences to various degree in the three groups and NSCLC patients with PRISm or COPD presented more unfavorable prognosis than patients with normal function. The expression of Testin correlated with lymph node metastasis, TNM stage and tumor invasion of NSCLC patients. Moreover, patients with low Testin expression exhibited poorer disease-free survival and overall survival than those with high Testin expression. In Cox regression analysis, we found that PRISm, COPD and Testin expression served as prognostic factors in NSCLC patients.

CONCLUSIONS

The presence of COPD or PRISm influenced systemic inflammatory response and prognosis of NSCLC patients. Testin expression correlated with clinicopathological features and could be potentially used as a prognostic marker in NSCLC.

The Expression of Testin, Ki-67 and p16 in Cervical Cancer Diagnostics

Testin is a protein expressed in normal human tissues, being responsible, with other cytoskeleton proteins, for the proper functioning of cell−cell junction areas and focal adhesion plaques. It takes part in the regulation of actin filament changes during cell spreading and motility. Loss of heterozygosity in the testin-encoding gene results in altered protein expression in many malignancies, as partly described for cervical cancer. The aim of our study was the assessment of the immunohistochemical (IHC) expression of testin in cervical cancer and its analysis in regard to clinical data as well the expression of the Ki-67 antigen and p16 protein. Moreover, testin expression was assessed by Western blot (WB) in commercially available cell lines. The IHC analysis disclosed that the expression of testin inversely correlated with p16 (r = −0.2104, p < 0.0465) and Ki-67 expression (r = −0.2359, p < 0.0278). Moreover, weaker testin expression was observed in cancer cases vs. control ones (p < 0.0113). The WB analysis of testin expression in the cervical cancer cell lines corresponded to the IHC results and showed a weaker expression compared to that in the control cell line. When we compared the expression of testin in cervical cancer cell lines, we found a weaker expression in HPV-negative cell lines. In summary, we found that the intensity of testin expression and the number of positive cells inversely correlated with the expression of Ki-67 (a marker of proliferation) and p16 (a marker of cell cycle dysregulation). This study shows that the combined assessment of testin, Ki-67 and p16 expression may improve cervical cancer diagnostics.

The relationship between TESTIN expression and the prognosis of colorectal cancer

BACKGROUND

Colorectal carcinoma (CRC) represents a most grave healthy burden worldwide. TESTIN has been confirmed as a predictive biomarker for several cancers. In the present study, we sought to assess the expression level and prognostic values of TESTIN in CRC.

METHODS

The levels of TESTIN mRNA and protein were detected in 132 paired CRC tissues and noncancerous ones via quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) assays, respectively. Chi-square test was adopted to analyze the association of TESTIN expression with clinicopathological profiles of CRC patients. To explore prognostic value of TESTIN, Kaplan-Meier curve and Cox regression analyses were employed.

RESULTS

TESTIN expression was down-regulated among CRC tissues in comparison to bordering cancer-free samples at both protein and mRNA levels (P < 0.001). Decreased TESTIN expression was closely related to poor tumor differentiation (P = 0.001) and advanced TNM stages (P = 0.001). CRC cases with low expression of TESTIN were more likely to undergo dismal overall survivals (log-rank P = 0.003). Multivariate Cox analysis unveiled that down-regulated expression of TESTIN was independently correlated with poor prognosis (HR=2.422, 95% CI=1.294-4.535, P = 0.006).

CONCLUSION

The down-regulation of TESTIN may predict dismal prognosis for CRC patients.

Silencing of Testin expression is a frequent event in spontaneous lymphomas from Trp53-mutant mice

The tumour suppressor gene, TES, is frequently methylated in many human tumours. Previously, we demonstrated that TES promoter methylation and transcriptional silencing was the most common molecular abnormality detected in childhood acute lymphoblastic leukaemia (ALL). Trp53-mutant mouse models predominantly develop B- and T-cell lymphomas, which are widely considered equivalent to childhood T and B ALL. In this study, we examined expression of Tes transcript and Testin protein in spontaneous tumours obtained from three Trp53-mutant mouse models. Using immunohistochemistry, we report that 47% of lymphomas lacked Testin protein compared to only 7% of non-lymphoid tumours. Further examination of the lymphomas from Trp53-null and Trp53-mΔpro homozygous mutant mice revealed that 63% and 69% respectively of the isolated lymphomas were Testin negative, which is similar to reported rates in childhood T-ALL. Surprisingly, lymphomas from Trp53-Δ122 mice were frequently Testin positive (> 60%), suggesting that the presence of the Trp53-Δ122 protein appeared to mitigate the requirement for Tes silencing in lymphomagenesis. Quantitative RT-PCR results confirmed that this lack of Testin protein was due to Tes transcriptional silencing, although bisulfite sequencing demonstrated that this was not due to promoter methylation. These results are consistent with the Testin protein having lymphoid tumour suppressor activity in both mice and humans.

The Role of Testin in Human Cancers

Testin is a protein expressed in almost all normal human tissues. It locates in the cytoplasm along stress fibers being recruited to focal adhesions. Together with zyxin and vasodilator stimulated protein it forms complexes with various cytoskeleton proteins such as actin, talin and paxilin. They jointly play significant role in cell motility and adhesion. In addition, their involvement in the cell cycle has been demonstrated. Expression of testin protein level correlates positively with percentage of cells in G1 phase, while overexpression can induce apoptosis and decreased colony forming ability. Decreased testin expression associate with loss by cells epithelial morphology and gain migratory and invasive properties of mesenchymal cells. Latest reports indicate that TES is a tumor suppressor gene which can contribute to cancerogenesis but the mechanism of loss TES gene expression is still unknown. Some authors point out hypermethylation of the CpG island as a main factor, however loss of heterozygosity may also play an important role [4, 5]. The altered expression of testin was found in malignant neoplasm, i.a. ovarian, lung, head and neck squamous cell cancer, breast, endometrial, colorectal, prostate and gastric cancers [1-9]. Testin participate in the processes of tumor growth, angiogenesis, and metastasis [10]. Many researchers stated involvement of testin in tumor progression, what suggest its potential usage in immunotherapy [7, 11]. Understanding the molecular functions of testin may be crucial in development personalized treatment. In the present manuscript up-to-date review of literature can be found.

Significance of Inactivated Genes in Leukemia: Pathogenesis and Prognosis

Epigenetic and genetic alterations are two mechanisms participating in leukemia, which can inactivate genes involved in leukemia pathogenesis or progression. The purpose of this review was to introduce various inactivated genes and evaluate their possible role in leukemia pathogenesis and prognosis. By searching the mesh words "Gene, Silencing AND Leukemia" in PubMed website, relevant English articles dealt with human subjects as of 2000 were included in this study. Gene inactivation in leukemia is largely mediated by promoter's hypermethylation of gene involving in cellular functions such as cell cycle, apoptosis, and gene transcription. Inactivated genes, such as ASPP1, TP53, IKZF1 and P15, may correlate with poor prognosis in acute lymphoid leukemia (ALL), chronic lymphoid leukemia (CLL), chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML), respectively. Gene inactivation may play a considerable role in leukemia pathogenesis and prognosis, which can be considered as complementary diagnostic tests to differentiate different leukemia types, determine leukemia prognosis, and also detect response to therapy. In general, this review showed some genes inactivated only in leukemia (with differences between B-ALL, T-ALL, CLL, AML and CML). These differences could be of interest as an additional tool to better categorize leukemia types. Furthermore; based on inactivated genes, a diverse classification of Leukemias could represent a powerful method to address a targeted therapy of the patients, in order to minimize side effects of conventional therapies and to enhance new drug strategies.

The PET and LIM1-2 domains of testin contribute to intramolecular and homodimeric interactions

The focal adhesion protein testin is a modular scaffold and tumour suppressor that consists of an N-terminal cysteine rich (CR) domain, a PET domain of unknown function and three C-terminal LIM domains. Testin has been proposed to have an open and a closed conformation based on the observation that its N-terminal half and C-terminal half directly interact. Here we extend the testin conformational model by demonstrating that testin can also form an antiparallel homodimer. In support of this extended model we determined that the testin region (amino acids 52–233) harbouring the PET domain interacts with the C-terminal LIM1-2 domains in vitro and in cells, and assign a critical role to tyrosine 288 in this interaction.

Testin is a tumor suppressor in non-small cell lung cancer

The Testin gene was previously identified in the fragile chromosomal region FRA7G at 7q31.2. It has been implicated in several types of cancers including prostate, ovarian, breast and gastric cancer. In the present study, we investigated the function of the candidate tumor-suppressor Testin gene in non-small cell lung cancer (NSCLC). In NSCLC cell lines, we observed lower expression of Testin compared to that noted in normal human bronchial epithelial cells. MTT assays, flow cytometry, clonogenic assay and invasion assay showed that the overexpression of the Testin gene inhibited cancer cell proliferation, invasion and colony formation. In tumor xenograft models, Testin markedly inhibited lung cancer cell xenograft formation and growth in athymic nude mice. Taken together, these data suggest that Testin plays an important role in the development and progression of NSCLC. Testin may be an effective novel target in NSCLC prevention and treatment.

Testin (TES) as a candidate tumour suppressor and prognostic marker in human astrocytoma

Astrocytomas are one of the most common brain tumours; however, the current methods used to characterize these tumours are inadequate. The establishment of molecular markers may identify variables required to improve tumour characterization and subtyping, and may aid to specify targets for improved treatment with essential prognostic value for patient survival. One such candidate is testin (TES), which was reported to have prognostic value for glioblastoma patients. However, the role of TES protein in gliomagenesis is currently unknown. In the present study, the methylation status of the TES promoter was investigated in post-operative astrocytoma tumours of different malignancy grade, and its association with the survival of astrocytoma patients was evaluated. In addition, the expression of TES protein was investigated in the same set of astrocytoma tumours tissue, and the association of protein expression with glioma patients survival was evaluated. The methylation status of TES was assessed by methylation-specific polymerase chain reaction in 138 different grade astrocytoma samples. Western blot analysis was used to characterize the expression pattern of TES in 86 different grade astrocytoma specimens: 13 of pathological grade I, 31 of pathological grade II, 17 of pathological grade III and 25 of pathological grade IV (glioblastoma). Statistical analyses were conducted to investigate the association between tumour molecular pattern, patient clinical variables and overall survival. The methylation analysis of the TES promoter exhibited a distinct profile between astrocytomas of different malignancy grade (P<0.001). Furthermore, gene promoter methylation was significantly associated with patients' age, survival and pathological grade (P<0.001). The protein expression level of TES was significantly lower in glioblastoma (grade IV astrocytoma) than in lower grade (II–III) astrocytoma tissue (P=0.028 and P=0.04, respectively). Additionally, short overall survival of patients was markedly associated with low TES protein expression (P=0.007). However, no association between TES methylation and TES protein expression was noticed. The present study demonstrated that decreased expression of TES may be important in tumour progression and prognosis in human astrocytomas. TES may be a useful marker for predicting the clinical outcome of astrocytoma patients.

Epigenetic regulation of cell signaling pathways in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is a heterogeneous cancer that is characterized by rapid and uncontrolled proliferation of immature B- or T-lymphoid precursors. Although ALL has been regarded as a genetic disease for many years, the crucial importance of epigenetic alterations in leukemogenesis has become increasingly evident. Epigenetic mechanisms, which include DNA methylation and histone modifications, are critical for gene regulation during many key biological processes. Here, we review the cell signaling pathways that are regulated by DNA methylation or histone modifications in ALL. Recent studies have highlighted the fundamental role of these modifications in ALL development, and suggested that future investigation into the specific genes and pathways that are altered by epigenetic mechanisms can contribute to the development of novel drug-based therapies for ALL.

TESTIN Induces Rapid Death and Suppresses Proliferation in Childhood B Acute Lymphoblastic Leukaemia Cells

Background

Childhood acute lymphoblastic leukaemia (ALL) is the most common malignancy in children. Despite high cure rates, side effects and late consequences of the intensive treatments are common. Unquestionably, the identification of new therapeutic targets will lead to safer, more effective treatments. We identified TES promoter methylation and transcriptional silencing as a very common molecular abnormality in childhood ALL, irrespective of molecular subtype. The aims of the present study were to demonstrate that TES promoter methylation is aberrant, to determine the effects of TES re-expression in ALL, and to determine if those effects are mediated via TP53 activity.

Methods

Normal fetal and adult tissue DNA was isolated and TES promoter methylation determined by Sequenom MassARRAY. Quantitative RT-PCR and immunoblot were used to confirm re-expression of TES in ALL cell lines after 5’-aza-2’-deoxycytidine (decitabine) exposure or transfection with TES expression plasmids. The effects of TES re-expression on ALL cells were investigated using standard cell proliferation, cell death and cell cycle assays.

Results

In this study, we confirm that the TES promoter is unmethylated in normal adult and fetal tissues. We report that decitabine treatment of ALL cell lines results in demethylation of the TES promoter and attendant expression of TES mRNA. Re-expression of TESTIN protein in ALL cells using expression plasmid transfection results in rapid cell death or cell cycle arrest independent of TP53 activity.

Conclusions

These results suggest that TES is aberrantly methylated in ALL and that re-expression of TESTIN has anti-leukaemia effects which point to novel therapeutic opportunities for childhood ALL.

Effects of TESTIN gene expression on proliferation and migration of the 5-8F nasopharyngeal carcinoma cell line

PURPOSE

To investigate effects of the TESTIN (TES) gene on proliferation and migration of highly metastatic nasopharyngeal carcinoma cell line 5-8F and the related mechanisms.

MATERIALS AND METHODS

The target gene of human nasopharyngeal carcinoma cell line 5-8F was amplified by PCR and cloned into the empty plasmid pEGFP-N1 to construct a eukaryotic expression vector pEGFP-N1-TES. This was then transfected into 5-8F cells. MTT assays, flow cytometry and scratch wound tests were used to detect the proliferation and migration of transfected 5-8F cells.

RESULTS

A cell model with stable and high expression of TES gene was successfully established. MTT assays showed that the OD value of 5-8F/TES cells was markedly lower than that of 5-8F/GFP cells and 5-8F cells (p<0.05). Flow cytometry showed that the apoptosis rate of 5-8F/TES cells was prominently increased compared with 5-8F/GFP cells and 5-8F cells (p<0.05). In vitro scratch wound assays showed that, the width of the wound area of 5-8F/TES cells narrowed slightly, while the width of the wound area of 5-8F/ GFP cells and 5-8F cells narrowed sharply, suggesting that the TES overexpression could inhibit the migration ability.

CONCLUSIONS

TES gene expression remarkably inhibits the proliferation of human nasopharyngeal carcinoma cell line 5-8F and reduces its migration in vitro. Thus, it may be a potential tumor suppressor gene for nasopharyngeal carcinoma.

Binding of the WASP/N-WASP-interacting protein WIP to actin regulates focal adhesion assembly and adhesion

The actin cytoskeleton is essential for cell adhesion and migration, functions important for tumor invasion. In addition to binding N-WASP/WASP, WIP binds and stabilizes F-actin. WIP(-/-) fibroblasts were used to test the role of WIP in F-actin function. WIP(-/-) cells had defective focal adhesion (FA), stress fiber assembly, and adherence to substrates, functions that were restored by transduction of wild-type WIP. Protein and mRNA levels of several FA constituents regulated by the myocardin-related transcription factor (MRTF)–serum response factor (SRF) transcription factor complex were reduced in WIP(-/-) fibroblasts. The level of G-actin, which sequesters MRTF in the cytoplasm, was increased, and nuclear localization of MRTF-A and SRF was reduced, in WIP(-/-) fibroblasts. Transfection of an MRTF-A mutant that constitutively translocates to the nucleus or transfection of constitutively active SRF restored FA and stress fiber assembly. Fibroblasts from knock-in mice expressing a WIP mutant that fails to bind actin phenocopied WIP(-/-) fibroblasts. Thus, WIP is a novel regulator of FA assembly and cell adhesion.

Downregulation of TES by hypermethylation in glioblastoma reduces cell apoptosis and predicts poor clinical outcome

BACKGROUND

Gliomas are the most common human brain tumors. Glioblastoma, also known as glioblastoma multiform (GBM), is the most aggressive, malignant, and lethal glioma. The investigation of prognostic and diagnostic molecular biomarkers in glioma patients to provide direction on clinical practice is urgent. Recent studies demonstrated that abnormal DNA methylation states play a key role in the pathogenesis of this kind of tumor. In this study, we want to identify a novel biomarker related to glioma initiation and find the role of the glioma-related gene.

METHODS

We performed a methylation-specific microarray on the promoter region to identify methylation gene(s) that may affect outcome of GBM patients. Normal and GBM tissues were collected from Tiantan Hospital. Genomic DNA was extracted from these tissues and analyzed with a DNA promoter methylation microarray. Testis derived transcript (TES) protein expression was analyzed by immunohistochemistry in paraffin-embedded patient tissues. Western blotting was used to detect TES protein expression in the GBM cell line U251 with or without 5-aza-dC treatment. Cell apoptosis was evaluated by flow cytometry analysis using Annexin V/PI staining.

RESULTS

We found that the TES promoter was hypermethylated in GBM compared to normal brain tissues under DNA promoter methylation microarray analysis. The GBM patients with TES hypermethylation had a short overall survival (P <0.05, log-rank test). Among GBM samples, reduced TES protein level was detected in 33 (89.2%) of 37 tumor tissues by immunohistochemical staining. Down regulation of TES was also correlated with worse patient outcome (P <0.05, log-rank test). Treatment on the GBM cell line U251 with 5-aza-dC can greatly increase TES expression, confirming the hypermethylation of TES promoter in GBM. Up-regulation of TES prompts U251 apoptosis significantly. This study demonstrated that both TES promoter hypermethylation and down-regulated protein expression significantly correlated with worse patient outcome. Treatment on the GBM cell line (U251) with 5-aza-dC can highly release TES expression resulting in significant apoptosis in these cells.

CONCLUSIONS

Our findings suggest that the TES gene is a novel tumor suppressor gene and might represent a valuable prognostic marker for glioblastoma, indicating a potential target for future GBM therapy.

DNA methylation alterations in grade II- and anaplastic pleomorphic xanthoastrocytoma

Background

Pleomorphic xanthoastrocytoma (PXA) is a rare WHO grade II tumor accounting for less than 1% of all astrocytomas. Malignant transformation into PXA with anaplastic features, is unusual and correlates with poorer outcome of the patients.

Methods

Using a DNA methylation custom array, we have quantified the DNA methylation level on the promoter sequence of 807 cancer-related genes of WHO grade II (n = 11) and III PXA (n = 2) and compared to normal brain tissue (n = 10) and glioblastoma (n = 87) samples. DNA methylation levels were further confirmed on independent samples by pyrosequencing of the promoter sequences.

Results

Increasing DNA promoter hypermethylation events were observed in anaplastic PXA as compared with grade II samples. We further validated differential hypermethylation of CD81, HCK, HOXA5, ASCL2 and TES on anaplastic PXA and grade II tumors. Moreover, these epigenetic alterations overlap those described in glioblastoma patients, suggesting common mechanisms of tumorigenesis.

Conclusions

Even taking into consideration the small size of our patient populations, our data strongly suggest that epigenome-wide profiling of PXA is a valuable tool to identify methylated genes, which may play a role in the malignant progression of PXA. These methylation alterations may provide useful biomarkers for decision-making in those patients with low-grade PXA displaying a high risk of malignant transformation.

Pharmacogenomic considerations of xenograft mouse models of acute leukemia

The use of combination chemotherapy to cure acute lymphoblastic leukemia in children and acute myeloid leukemia in adults emerged for acute myeloid leukemia in the 1960s and for acute lymphoblastic leukemia in the 1980s as a paradigm for curing any disseminated cancer. This article summarizes recent developments and considerations in the use of acute leukemia xenografts established in immunodeficient mice to elucidate the genetic and genomic basis of acute leukemia pathogenesis and treatment response.

Differential expression of testin and survivin in breast cancer subtypes

Testin (TES) is a putative tumour-suppressor gene downregulated in various types of cancers. Survivin is a nodal protein involved in multiple signalling pathways, tumour maintenance and inhibition of apoptosis. Previous studies indicate that TES and survivin can functionally interact and modulate cell death and proliferation in breast cancer cells. The aim of the present study was to investigate the expression and prognostic relevance of TES and survivin in breast cancer subtypes examining a large cohort of breast cancer patients. We determined the expression of TES and survivin by immunohistochemistry (IHC) in tissue samples from 242 breast cancer patients diagnosed between 1981 and 2009. The expression of these proteins was compared with clinical and pathological data. There was a significant association of nuclear survivin overexpression and TES downregulation with triple-negative tumours [P=0.009; univariate odds ratio (OR), 3.20; 95% CI, 1.34-7.66] (P=0.018; multivariate OR, 2.90; 95% CI, 1.20‑6.97). A further significant correlation was observed between TES downregulation and the luminal B subtype (P=0.019, univariate OR: 2.90; 95% CI, 1.19‑7.06) (P=0.032, multivariate OR, 2.67; 95% CI, 1.09-6.65), independent of survivin expression. Our results demonstrated a statistically significant association between TES downregulation and highly aggressive breast tumour subtypes, such as triple-negative and luminal B tumours, along with the prognostic relevance of nuclear expression of survivin. To our knowledge, this is the first demonstration of such an association.

Widespread resetting of DNA methylation in glioblastoma-initiating cells suppresses malignant cellular behavior in a lineage-dependent manner

Epigenetic changes are frequently observed in cancer. However, their role in establishing or sustaining the malignant state has been difficult to determine due to the lack of experimental tools that enable resetting of epigenetic abnormalities. To address this, we applied induced pluripotent stem cell (iPSC) reprogramming techniques to invoke widespread epigenetic resetting of glioblastoma (GBM)-derived neural stem (GNS) cells. GBM iPSCs (GiPSCs) were subsequently redifferentiated to the neural lineage to assess the impact of cancer-specific epigenetic abnormalities on tumorigenicity. GiPSCs and their differentiating derivatives display widespread resetting of common GBM-associated changes, such as DNA hypermethylation of promoter regions of the cell motility regulator TES (testis-derived transcript), the tumor suppressor cyclin-dependent kinase inhibitor 1C (CDKN1C; p57KIP2), and many polycomb-repressive complex 2 (PRC2) target genes (e.g., SFRP2). Surprisingly, despite such global epigenetic reconfiguration, GiPSC-derived neural progenitors remained highly malignant upon xenotransplantation. Only when GiPSCs were directed to nonneural cell types did we observe sustained expression of reactivated tumor suppressors and reduced infiltrative behavior. These data suggest that imposing an epigenome associated with an alternative developmental lineage can suppress malignant behavior. However, in the context of the neural lineage, widespread resetting of GBM-associated epigenetic abnormalities is not sufficient to override the cancer genome.

History of Parvovirus B19 infection is associated with a DNA methylation signature in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) likely has a multistep etiology, with initial genetic aberrations occurring early in life. An abnormal immune response to common infections has emerged as a plausible candidate for triggering the proliferation of pre-leukemic clones and the fixation of secondary genetic mutations and epigenetic alterations. We investigated whether evidence of infection with a specific common myelotropic childhood virus, parvovirus B19 (PVB19), relates to patterns of gene promoter DNA methylation in ALL patients. We serologically tested bone marrow samples at diagnosis of B-cell ALL for PVB19 infection and DNA methylation using a high-throughput bead array and found that 4.2% and 36.7% of samples were seroreactive to PVB19 IgM and IgG, respectively. Leukemia samples were grouped by DNA methylation pattern. Controlling for age and immunophenotype, unsupervised modeling confirmed that the DNA methylation pattern was associated with history of PVB19 (assessed by IgG, p = 0.02), but not recent infection (assessed by IgM). Replication assays on single genes were consistent with the association. The data indicate that a common viral illness may drive specific DNA methylation patterns in susceptible B-precursor cells, contributing to the leukemogenic potential of such cells. Infections may impact childhood leukemia by altering DNA methylation patterns and specific key genes in susceptible cells; these changes may be retained even after the clearance of infection.