Publications by authors named "Jean-Pierre Issa"

Almost 50% of patients with myelodysplastic syndrome (MDS) are refractory to first-line hypomethylating agents (HMAs), which presents a significant clinical challenge considering the lack of options for salvage. Past work revealed that immune checkpoint molecules on peripheral myeloblasts and immune cells are up-regulated after HMA treatment. Therefore, we conducted a Phase I/II clinical trial combining guadecitabine (an HMA) and atezolizumab (an immune checkpoint inhibitor) to treat HMA-relapsed or refractory (HMA-R/R) MDS patients.

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DNA methyltransferase and poly(ADP-ribose) polymerase inhibitors (DNMTis, PARPis) induce a stimulator of interferon (IFN) genes (STING)-dependent pathogen mimicry response (PMR) in ovarian (OC) and other cancers. We now show that combining DNMTis and PARPis upregulates expression of a little-studied nucleic-acid sensor, NFX1-type zinc finger-containing 1 protein (ZNFX1). We demonstrate that ZNFX1 is a novel master regulator for PMR induction in mitochondria, serving as a gateway for STING-dependent PMR.

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  • The intestinal microbiota plays a crucial role in the development of colorectal cancer (CRC), possibly influencing DNA methylation.
  • In a study of 203 CRC tumor cases, researchers found significant enrichment of specific bacteria (including those labeled "Superhigh") in CIMP-positive samples, indicating a potential link between gut bacteria and tumor characteristics.
  • Using data from The Cancer Genome Atlas, the study demonstrated that these bacterial populations were associated with alterations in DNA methylation, suggesting that microbiota could be a factor in CRC progression through its influence on epigenetic changes.
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  • - CpG islands near gene promoters are usually unmethylated, but when they become hypermethylated, it can lead to various diseases, including cancer.
  • - This study analyzed colorectal cancer methylation patterns and identified 610 genes that had disrupted protective barriers against methylation.
  • - A specific 41-bp sequence motif (MB-41) was found to be crucial in protecting these CpG islands, and its loss resulted in increased hypermethylation, suggesting its role as a novel methylation barrier in the human genome.
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Background: Inhibition of cyclin-dependent kinase 9 (CDK9), a novel epigenetic target in cancer, can reactivate epigenetically silenced genes in cancer by dephosphorylating the SWI/SNF chromatin remodeler BRG1. Here, we characterized the anti-tumor efficacy of MC180295, a newly developed CDK9 inhibitor.

Methods: In this study, we explored the pharmacokinetics of MC180295 in mice and rats, and tested the anti-tumor efficacy of MC180295, and its enantiomers, in multiple cancer cell lines and mouse models.

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The United States continues to be impacted by decades of an opioid misuse epidemic, worsened by the COVID-19 pandemic and by the growing prevalence of highly potent synthetic opioids (HPSO) such as fentanyl. In instances of a toxicity event, first-response administration of reversal medications such as naloxone can be insufficient to fully counteract the effects of HPSO, particularly when there is co-occurring substance use. In an effort to characterize and study this multi-faceted problem, the Camden Opioid Research Initiative (CORI) has been formed.

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  • The study identifies Id3 as a critical transcriptional regulator that maintains T-cell responses in target tissues, particularly in graft-versus-host disease (GVHD) in mice.
  • Loss of Id3 leads to improper PD-1 expression and a reduction in functional T helper 1 (Th1) cells, which impairs GVHD development but can be restored through PD-1 blockade.
  • The research highlights the potential of targeting Id3 in T-cell immunotherapy by revealing its role in modulating T-cell function and protecting against PD-1-mediated suppression.
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This phase 3 study evaluated the efficacy and safety of the new hypomethylating agent guadecitabine (n = 408) vs a preselected treatment choice (TC; n = 407) of azacitidine, decitabine, or low-dose cytarabine in patients with acute myeloid leukemia unfit to receive intensive induction chemotherapy. Half of the patients (50%) had poor Eastern Cooperative Oncology Group Performance Status (2-3). The coprimary end points were complete remission (19% and 17% of patients for guadecitabine and TC, respectively [stratified P = .

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Purpose: On the basis of preclinical evidence of epigenetic contribution to sensitivity and resistance to immune checkpoint inhibitors (ICI), we hypothesized that guadecitabine (hypomethylating agent) and atezolizumab [anti-programmed cell death ligand 1 (PD-L1)] together would potentiate a clinical response in patients with metastatic urothelial carcinoma (UC) unresponsive to initial immune checkpoint blockade therapy.

Patients And Methods: We designed a single arm phase II study (NCT03179943) with a safety run-in to identify the recommended phase II dose of the combination therapy of guadecitabine and atezolizumab. Patients with recurrent/advanced UC who had previously progressed on ICI therapy with programmed cell death protein 1 or PD-L1 targeting agents were eligible.

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Background: Epigenetic marks are encoded by DNA methylation and accumulate errors as organisms age. This drift correlates with lifespan, but the biology of how this occurs is still unexplained. We analyze DNA methylation with age in mouse intestinal stem cells and compare them to nonstem cells.

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Background & Aims: Aberrant DNA methylation is frequent in colorectal cancer (CRC), but underlying mechanisms and pathologic consequences are poorly understood.

Methods: We disrupted active DNA demethylation genes Tet1 and/or Tdg from Apc mice and characterized the methylome and transcriptome of colonic adenomas. Data were compared to human colonic adenocarcinomas (COAD) in The Cancer Genome Atlas.

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Background: Changes in gene-specific promoter methylation may result from aging and environmental influences. Atherosclerosis is associated with aging and environmental effects. Thus, promoter methylation profiling may be used as an epigenetic tool to evaluate the impact of aging and the environment on atherosclerosis development.

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DNA methylation is an epigenetic process altered in cancer and ageing. Age-related methylation drift can be used to estimate lifespan and can be influenced by extrinsic factors such as diet. Here, we report that non-pathogenic microbiota accelerate age-related methylation drift in the colon when compared with germ-free mice.

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Purpose: We hypothesized that resistance to hypomethylating agents (HMA) among patients with myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) would be overcome by combining a programmed death-ligand 1 antibody with an HMA.

Patients And Methods: We conducted a Phase I/II, multicenter clinical trial for patients with MDS not achieving an International Working Group response after at least 4 cycles of an HMA ("refractory") or progressing after a response ("relapsed") with 3+ or higher risk MDS by the revised International Prognostic Scoring System (IPSS-R) and CMML-1 or -2. Phase I consisted of a 3+3 dose-escalation design beginning with guadecitabine at 30 mg/m2 and escalating to 60 mg/m2 Days 1 to 5 with fixed-dose atezolizumab: 840 mg intravenously Days 8 and 22 of a 28-day cycle.

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Unlabelled: Nongenetic predisposition to colorectal cancer continues to be difficult to measure precisely, hampering efforts in targeted prevention and screening. Epigenetic changes in the normal mucosa of patients with colorectal cancer can serve as a tool in predicting colorectal cancer outcomes. We identified epigenetic changes affecting the normal mucosa of patients with colorectal cancer.

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Aberrant transcription in cancer cells involves the silencing of tumor suppressor genes (TSGs) and activation of oncogenes. Transcriptomic changes are associated with epigenomic alterations such as DNA-hypermethylation, histone deacetylation, and chromatin condensation in promoter regions of silenced TSGs. To discover novel drugs that trigger TSG reactivation in cancer cells, we used a GFP-reporter system whose expression is silenced by promoter DNA hypermethylation and histone deacetylation.

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The landmark paper by Kane and colleagues was the first report of DNA methylation in the promoter of the human MLH1 gene in sporadic colon cancers with mismatch repair (MMR) deficiency. In both cell lines and primary tumors, promoter methylation was associated with loss of MLH1 protein expression and with a lack of mutations in the MLH1 coding region. Together with subsequent papers that showed that this methylation was directly responsible for loss of MLH1 expression and MMR deficiency, the observation expanded the two-hit hypothesis of tumor suppressor gene loss in cancer to include both genetic and epigenetic mechanisms of gene inactivation.

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Triple-negative breast cancers (TNBCs) are very heterogenous, molecularly diverse, and are characterized by a high propensity to relapse or metastasize. Clinically, TNBC remains a diagnosis of exclusion by the lack of hormone receptors (Estrogen Receptor (ER) and Progesterone Receptor (PR)) as well as the absence of overexpression and/or amplification of HER2. DNA methylation plays an important role in breast cancer carcinogenesis and TNBCs have a distinct DNA methylation profile characterized by marked hypomethylation and lower gains of methylations compared to all other subtypes.

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Background: DNA methylation alterations have similar patterns in normal aging tissue and in cancer. In this study, we investigated breast tissue-specific age-related DNA methylation alterations and used those methylation sites to identify individuals with outlier phenotypes. Outlier phenotype is identified by unsupervised anomaly detection algorithms and is defined by individuals who have normal tissue age-dependent DNA methylation levels that vary dramatically from the population mean.

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The evolution of DNA methylome and methylation intra-tumor heterogeneity (ITH) during early carcinogenesis of lung adenocarcinoma has not been systematically studied. We perform reduced representation bisulfite sequencing of invasive lung adenocarcinoma and its precursors, atypical adenomatous hyperplasia, adenocarcinoma in situ and minimally invasive adenocarcinoma. We observe gradual increase of methylation aberrations and significantly higher level of methylation ITH in later-stage lesions.

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Promoter DNA methylation is a well-established mechanism of transcription repression, though its global correlation with gene expression is weak. This weak correlation can be attributed to the failure of current methylation quantification methods to consider the heterogeneity among sequenced bulk cells. Here, we introduce Cell Heterogeneity-Adjusted cLonal Methylation (CHALM) as a methylation quantification method.

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  • High folic acid intake from food fortification and supplements raises concerns due to its association with liver issues and changes in lipid metabolism, particularly affecting methylenetetrahydrofolate reductase (MTHFR) levels.
  • The study found that a high folic acid diet led to DNA hypomethylation in the lipolysis-stimulated lipoprotein receptor (Lsr) gene, which regulates cholesterol uptake in the liver.
  • This hypomethylation increased Lsr expression, disrupted various cholesterol-related genes, and resulted in higher hepatic cholesterol levels, posing potential risks for individuals with MTHFR deficiencies.
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Background: Atherosclerosis is the main cause of cardiovascular diseases such as ischemic stroke and coronary heart disease. Gene-specific promoter methylation changes have been suggested as one of the causes underlying the development of atherosclerosis. We aimed to identify and validate specific genes that are differentially expressed through promoter methylation in atherosclerotic plaques.

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