Publications

<p>Protein levels of ERBB4 was measured by FACS (A) and immunoblotting (B) in JEKO1 cells engineered to increase the expression of ERBB. Drug sensitivity for idelalisib (C) and ibrutinib (D) was evaluated in the different clones of engineered JEKO1. (A) Representative plot of two independent experiments. Boxplot and density plot shows the median MFI values of the two replicates: negative control (black), JEKO1-CNT (control, grey) and JEKO1-ERBB4 (sgRNA-erbb4, red). Results are presented from Welch Two Sample test performed on MFI values of the two experiments. (B) Immunoblotting for ERBB4 in JEKO1-CNT (control, grey) and JEKO1-ERBB4 (sgRNA-erbb4, red). Representative image of two independent experiments. Data on the barplot represents the mean of two experiments, errors bars represent standard deviation of the mean. * for p<0.05 from a t-test. (C-D) Cell viability was evaluated by MTT assay (72h). JEKO1-CNT (control, blue) and JEKO1-ERBB4 (ERBB4-sgRNA3 in red) cells were stimulated with PBS (left panel) or HBEGF (30ng/mL, right panel) for 4 hours and the exposed to increasing concentrations of idelalisib (C) or ibrutinib (D). Error bars correspond to standard deviation of the mean. Data derived from two independent experiments. Statistically significant differences were evaluated by moderated t-test comparing each treatment to control. * for p<0.05.</p>

<p>Supplementary Table 3. The twenty-eight HDAC inhibitors used in the study and their specificity</p>

Epigenetic events, resulting changes in gene expression capacity, are important in tumour progression, and variation in genes involved in epigenetic mechanisms might therefore be important in cancer susceptibility. To evaluate this hypothesis, we examined common variants in 12 genes coding for DNA methyltransferases (DNMT), histone acetyltransferases, histone deacetyltransferases, histone methyltrasferases and methyl-CpG binding domain proteins, for association with breast cancer in a large case–control study ( N cases = 4474 and N controls = 4580). We identified 63 single nucleotide polymorphisms (SNPs) that efficiently tag all the known common variants in these genes, and are also expected to tag any unknown SNP in each gene. We found some evidence for association for six SNPs: DNMT3b-c 31721 t [ P (2 df) = 0.007], PRDM2-c 99243 t [ P (2 df) = 0.03] and t 105413 c [ P -recessive = 0.05], EHMT1-g -9441 a [ P (2df) = 0.05] and g 41451 t ( P -trend = 0.04), and EHMT2- S237S [ P (2df) = 0.04]. The most significant result was for DNMT3b-c 31721 t ( P -trend = 0.124 after adjusting for multiple testing). However, there were three other results with P < 0.05. The permutation-based probability of this occurring by chance was 0.335. These significant SNPs were genotyped in 75 human cancer cell lines from different tumour types to assess if there was an association between them and six epigenetic measures. No statistically significant association was found. However, a trend was observed: homozygotes for the rare alleles of the EHMT1 , EHMT2 and PRDM2 had a mean value for both trimethylation of K9 and K27 of histone H3 remarkably different to the homozygotes for the common alleles. Thus, these preliminary observations suggest the possible existence of a functional consequence of harbouring these genetic variants in histone methyltransferases, and warrant the design of larger epidemiological and biochemical studies to establish the true meaning of these findings.

&lt;p&gt;Clonal landscape of MDS patients&lt;/p&gt;

Metformin is currently considered as a promising anticancer agent in addition to its anti-diabetic effect. To better individualize metformin therapy and explore novel molecular mechanisms in cancer treatment, we conducted a pharmacogenomic study using 266 lymphoblastoid cell lines (LCLs). Metformin cytotoxicity assay was performed using the MTS assay. Genome-wide association (GWA) analyses were performed in LCLs using 1.3 million SNPs, 485k DNA methylation probes, 54k mRNA expression probe sets, and metformin cytotoxicity (IC50s). Top candidate genes were functionally validated using siRNA screening, followed by MTS assay in breast cancer cell lines. Further study of one top candidate, STUB1, was performed to elucidate the mechanisms by which STUB1 might contribute to metformin action. GWA analyses in LCLs identified 198 mRNA expression probe sets, 12 SNP loci, and 5 DNA methylation loci associated with metformin IC50 with P-values <10−4 or <10−5. Integrated SNP/methylation loci-expression-IC50 analyses found 3 SNP loci or 5 DNA methylation loci associated with metformin IC50 through trans-regulation of expression of 11 or 26 genes with P-value <10−4. Functional validation of top 61 candidate genes in 4 IPA networks indicated down regulation of 14 genes significantly altered metformin sensitivity in two breast cancer cell lines. Mechanistic studies revealed that the E3 ubiquitin ligase, STUB1, could influence metformin response by facilitating proteasome-mediated degradation of cyclin A. GWAS using a genomic data-enriched LCL model system, together with functional and mechanistic studies using cancer cell lines, help us to identify novel genetic and epigenetic biomarkers involved in metformin anticancer response.

Germline mutations in the Exostoses-1 gene (EXT1) are found in hereditary multiple exostoses syndrome, which is characterized by the formation of osteochondromas and an increased risk of chondrosarcomas and osteosarcomas. However, despite its putative tumor-suppressor function, little is known of the contribution of EXT1 to human sporadic malignancies. Here, we report that EXT1 function is abrogated in human cancer cells by transcriptional silencing associated with CpG island promoter hypermethylation. We also show that, at the biochemical and cellular levels, the epigenetic inactivation of EXT1, a glycosyltransferase, leads to the loss of heparan sulfate (HS) synthesis. Reduced HS production can be reversed by the use of a DNA demethylating agent. Furthermore, the re‐introduction of EXT1 into cancer cell lines displaying methylation-dependent silencing of EXT1 induces tumor-suppressor-like features, e.g. reduced colony formation density and tumor growth in nude mouse xenograft models. Screening a large collection of human cancer cell lines (n=79) and primary tumors (n=454) from different cell types, we found that EXT1 CpG island hypermethylation was common in leukemia, especially acute promyelocytic leukemia and acute lymphoblastic leukemia, and non-melanoma skin cancer. These findings highlight the importance of EXT1 epigenetic inactivation, leading to an abrogation of HS biosynthesis, in the processes of tumor onset and progression.

ABSTRACT Objective To assess the association between DNA methylation and acute myocardial infarction, the predictive added value of the identified methylation marks, and the causality of those associations. Approach and Results We conducted a case-control, two-stage, epigenome-wide association study on acute myocardial infarction (n discovery =391, n validation =204). DNA methylation was assessed using the Infinium MethylationEPIC BeadChip (over 850,000 CpGs). DNA methylation was the exposure variable and myocardial infarction the outcome of interest. After a fixed-effects meta-analysis, 34 CpGs fulfilled Bonferroni significance. These findings were also analysed in two independent cohort studies (n∼1,800 and n∼2,500) with incident coronary (CHD) and cardiovascular disease (CVD). The Infinium HumanMethylation450 BeadChip was used in these two studies (over 480,000 CpGs) and only 12 of the 34 CpGs were available in those samples. Finally, we validated four of them in association with incident CHD: AHRR -mapping cg05575921, PTCD2- mapping cg25769469, intergenic cg21566642 and MPO -mapping cg04988978. The four CpGs were also associated with classical cardiovascular risk factors. A methylation risk score based on those CpGs did not improve the predictive capacity of the Framingham risk function. To assess the causal effects of those CpGs we performed Mendelian randomization analysis but only one metQTL could be identified and the results were not conclusive. Conclusions We have identified 34 CpGs related to acute myocardial infarction. These loci highlight the relevance of smoking, lipid metabolism, and inflammation in the biological mechanisms related to myocardial infarction. Four were additionally associated with incident CHD and CVD but did not provide additional predictive information.

Some but not all neonates are affected by prenatal exposure to serotonin reuptake inhibitor antidepressants (SRI) and maternal mood disturbances. Distinguishing the impact of these 2 exposures is challenging and raises critical questions about whether pharmacological, genetic, or epigenetic factors can explain the spectrum of reported outcomes. Using unbiased DNA methylation array measurements followed by a detailed candidate gene approach, we examined whether prenatal SRI exposure was associated with neonatal DNA methylation changes and whether such changes were associated with differences in birth outcomes. Prenatal SRI exposure was first associated with increased DNA methylation status primarily at <i>CYP2E1</i>(β_Non-exposed = 0.06, β_SRI-exposed = 0.30, FDR = 0); however, this finding could not be distinguished from the potential impact of prenatal maternal depressed mood. Then, using pyrosequencing of <i>CYP2E1</i> regulatory regions in an expanded cohort, higher DNA methylation status—both the mean across 16 CpG sites (<i>P</i> &lt; 0.01) and at each specific CpG site (<i>P</i> &lt; 0.05)—was associated with exposure to lower 3rd trimester maternal depressed mood symptoms only in the SRI-exposed neonates, indicating a maternal mood x SRI exposure interaction. In addition, higher DNA methylation levels at CpG2 (<i>P</i> = 0.04), CpG9 (<i>P</i> = 0.04) and CpG10 (<i>P</i> = 0.02), in the interrogated <i>CYP2E1</i> region, were associated with increased birth weight independently of prenatal maternal mood, SRI drug exposure, or gestational age at birth. Prenatal SRI antidepressant exposure and maternal depressed mood were associated with altered neonatal <i>CYP2E1</i> DNA methylation status, which, in turn, appeared to be associated with birth weight.

Deficiency in DNA MMR activity results in tumors with a hypermutator phenotype, termed microsatellite instability (MSI). Beyond its utility in Lynch syndrome screening algorithms, today MSI has gained importance as predictive biomarker for various anti-PD-1 therapies across many different tumor types. Over the past years, many computational methods have emerged to infer MSI using either DNA- or RNA-based approaches. Considering this together with the fact that MSI-high tumors frequently exhibit a hypermethylated phenotype, herein we developed and validated MSIMEP, a computational tool for predicting MSI status from microarray DNA methylation tumor profiles of colorectal cancer samples. We demonstrated that MSIMEP optimized and reduced models have high performance in predicting MSI in different colorectal cancer cohorts. Moreover, we tested its consistency in other tumor types with high prevalence of MSI such as gastric and endometrial cancers. Finally, we demonstrated better performance of both MSIMEP models vis-à-vis a MLH1 promoter methylation-based one in colorectal cancer.

Supplementary Data from Identification of PMF1 Methylation in Association with Bladder Cancer Progression

&lt;p&gt;Fisher exact test for each mutated pathway, comparing responders vs. non-responders at diagnosis&lt;/p&gt;

Abstract The SMARCA4 / BRG1 gene product is a component of the SWI‐SNF chromatin‐remodeling complex and regulates gene expression by disrupting histone‐DNA contacts in an ATP‐dependent manner. Inactivating mutations of the SMARCA4 gene, on chromosome arm 19p, are present in several human cancer cell lines, including cell lines derived from lung cancers. Interestingly, loss of heterozygosity (LOH) at 19p and absence of the SMARCA4 protein have been reported in lung tumors. To evaluate further the possible contribution of SMARCA4 gene inactivation to lung carcinogenesis, we performed a complete analysis of the SMARCA4 gene to search for (a) point mutations in all 35 coding exons, including an existing splicing variant and the intron–exon boundaries, and (b) abrogation of gene expression through promoter hypermethylation by using the methylation‐specific polymerase chain reaction (MSP) assay. We selected genomic DNA from 20 lung primary tumors with LOH on 19p for the screening of point mutations and 10 lung cancer cell lines and 52 lung primary tumors for the MSP analysis. Through our mutational screening, we identified an in‐frame and germ‐line insertion of 24 bp in exon 4 whose biological relevance is unknown. This variant was not detected in the germ line of the 62 additional individuals analyzed, indicating it is not a common polymorphism. Moreover, two missense alterations were identified in the tumors of 2 patients, a somatic Gly1160Arg mutation and a Ser1176Cys mutation. Neither was present in the germ line of the 51 additional lung cancer individuals tested. Because these mutations lead to substitution of highly conserved amino acids, they may affect the ATPase function of the protein. Finally, no promoter hypermethylation was observed in any lung primary tumor or cancer cell line, indicating that this is not a major mechanism for SMARCA4 inactivation during lung carcinogenesis. In conclusion, our data revealed that somatic point mutations of the SMARCA4 gene are present in a small subset of lung tumors, although mutations affecting the ATPase domain may be a hot‐spot for SMARCA4 gene inactivation. We cannot rule out that other mechanisms, such as complete or partial deletions of the SMARCA4 gene, are contributing to the loss of the SMARCA4 protein in lung cancer. © 2004 Wiley‐Liss, Inc.

&lt;p&gt;Panel of kinases analyzed in the Phospho Flow experiments of parental and resistant cells by flow cytometry.&lt;/p&gt;