Epigenetic dysregulation in myeloid malignancies

The Ataxia-telangiectasia mutated (ATM) is the most important gene for repairing the DNA in Myelodysplastic Neoplasm

Myelodysplastic Neoplasm (MDS) is a cancer associated with aging, often leading to acute myeloid leukemia (AML). One of its hallmarks is hypermethylation, particularly in genes responsible for DNA repair. This study aimed to evaluate the methylation and mutation status of DNA repair genes (single-strand - XPA, XPC, XPG, CSA, CSB and double-strand - ATM, BRCA1, BRCA2, LIG4, RAD51) in MDS across three patient cohorts (Cohort A-56, Cohort B-100, Cohort C-76), using methods like pyrosequencing, real-time PCR, immunohistochemistry, and mutation screening. Results showed that XPA had higher methylation in low-risk MDS compared to high-risk MDS. For double-strand repair genes, ATM displayed higher methylation in patients who transformed to AML (p = 0.016). ATM gene expression was downregulated in MDS compared to controls (p = 0.042). When patients were classified according to the WHO 2022 guidelines, ATM expression progressively decreased from low-risk subtypes (e.g., Hypoplastic MDS) to high-risk MDS and AML. Patients who transformed to AML had a higher 5mC/5hmC ratio compared to those who didn't (p = 0.045). Additionally, poor cytogenetic risk patients had higher tissue methylation scores than those with good risk (p = 0.035). Analysis using the cBioPortal platform identified ATM as the most frequently mutated DNA repair gene, with various mutations, such as frameshift and missense, most of which were classified as oncogenic. The findings suggest that ATM is frequently silenced or downregulated in MDS due to methylation or mutations, contributing to the progression to AML. This highlights ATM's potential role in the disease's advancement and as a target for future therapeutic strategies.

A View of Myeloid Transformation through the Hallmarks of Cancer

The development of myeloid malignancies is influenced by a range of cell-intrinsic and cell-extrinsic factors, which can be conceptualized using the hallmarks of cancer. Although many facets of myeloid transformation are similar to those in solid tumors, there are also notable differences. Unlike solid tumors, hematologic malignancies typically exhibit fewer genetic mutations, which have been well characterized. However, understanding the cell-extrinsic factors contributing to myeloid malignancies can be challenging due to the complex interactions in the hematopoietic microenvironment. Researchers need to focus on these intricate factors to prevent the early onset of myeloid transformation and develop appropriate interventions. Significance: Myeloid malignancies are common in the elderly, and acute myeloid leukemia has an adverse prognosis in older patients. Investigating cell-extrinsic factors influencing myeloid malignancies is crucial to developing approaches for preventing or halting disease progression and predicting clinical outcomes in patients with advanced disease. Whereas successful intervention may require targeting various mechanisms, understanding the contribution of each cell-extrinsic factor will help prioritize clinical targets.

Impact of heat and cold shock on epigenetics and chromatin structure

Cells are continuously exposed to various sources of insults, among which temperature variations are extremely common. Epigenetic mechanisms, critical players in gene expression regulation, undergo alterations due to these stressors, potentially leading to health issues. Despite the significance of DNA methylation and histone modifications in gene expression regulation, their changes following heat and cold shock in human cells remain poorly understood. In this study, we investigated the epigenetic profiles of human cells subjected to hyperthermia and hypothermia, revealing significant variations. Heat shock primarily led to DNA methylation increments and epigenetic modifications associated with gene expression silencing. In contrast, cold shock presented a complex scenario, with both methylation and demethylation levels increasing, indicating different epigenetic responses to the opposite thermal stresses. These temperature-induced alterations in the epigenome, particularly their impact on chromatin structural organization, represent an understudied area that could offer important insights into genome function and potential prospects for therapeutic targets.

Current landscape of translational and clinical research in myelodysplastic syndromes/neoplasms (MDS): Proceedings from the 1st International Workshop on MDS (iwMDS) Of the International Consortium for MDS (icMDS)

Biological events that contribute to the pathogenesis of myelodysplastic syndromes/neoplasms (MDS) are becoming increasingly characterized and are being translated into rationally designed therapeutic strategies. Herein, we provide updates from the first International Workshop on MDS (iwMDS) of the International Consortium for MDS (icMDS) detailing recent advances in understanding the genetic landscape of MDS, including germline predisposition, epigenetic and immune dysregulation, the complexities of clonal hematopoiesis progression to MDS, as well as novel animal models of the disease. Connected to this progress is the development of novel therapies targeting specific molecular alterations, the innate immune system, and immune checkpoint inhibitors. While some of these agents have entered clinical trials (e.g., splicing modulators, IRAK1/4 inhibitors, anti-CD47 and anti-TIM3 antibodies, and cellular therapies), none have been approved for MDS. Additional preclinical and clinical work is needed to develop a truly individualized approach to the care of MDS patients.

A Comprehensive Overview of Recent Advances in Epigenetics in Pediatric Acute Lymphoblastic Leukemia

Recent years have brought a novel insight into our understanding of childhood acute lymphoblastic leukemia (ALL), along with several breakthrough treatment methods. However, multiple aspects of mechanisms behind this disease remain to be elucidated. Evidence suggests that leukemogenesis in ALL is widely influenced by epigenetic modifications. These changes include: DNA hypermethylation, histone modification and miRNA alteration. DNA hypermethylation in promoter regions, which leads to silencing of tumor suppressor genes, is a common epigenetic alteration in ALL. Histone modifications are mainly caused by an increased expression of histone deacetylases. A dysregulation of miRNA results in changes in the expression of their target genes. To date, several hundred genes were identified as suppressed by epigenetic mechanisms in ALL. What is promising is that epigenetic alterations in ALL may be used as potential biomarkers for classification of subtypes, predicting relapse and disease progression and assessing minimal residual disease. Furthermore, since epigenetic lesions are potentially reversible, an activation of epigenetically silenced genes with the use of hypomethylating agents or histone deacetylase inhibitors may be utilized as a therapeutic strategy for ALL. The following review summarizes our current knowledge about epigenetic modifications in ALL and describes potential uses of epigenetics in the clinical management of this disease.

Methylated Septin9 has moderate diagnostic value in colorectal cancer detection in Chinese population: a multicenter study

BACKGROUND

The detection rate of methylated Septin9 (mSEPT9) in colorectal cancer (CRC) is varied greatly across the studies. This study aimed to evaluate the diagnostic ability of mSEPT9 in CRC, and compare the diagnostic efficacy with fecal immunochemical test (FIT).

METHODS

326 subjects from four centers were prospectively recruited, including 179 CRC and 147 non-CRC subjects. The plasma was collected for mSEPT9 and CEA, AFP, CA125, CA153 and CA199 test, and fecal samples for FIT tests. Sensitivity, specificity and area under the curve (AUC) of receiver operating characteristic curve were calculated to evaluate the diagnostic value of each biomarker.

RESULTS

The positive rate in mSEPT9 and FIT, and the level of CEA, CA125 and CA199 were significantly higher in CRC compared with non-CRC subjects. The mSEPT9 positive rate was not associated with TNM stage and tumor stage. The sensitivity, specificity and AUC of mSEPT9 in diagnostic CRC were 0.77, 0.88 and 0.82, respectively, while the value in FIT was 0.88, 0.80 and 0.83, respectively. mSEPT9 and FIT have higher AUC value than that of CEA, CA125 and CA199. Combination of both mSEPT9 and FIT positive increased sensitivity and AUC to 0.98 and 0.83, respectively, but the specificity was declined. mSEPT9 has a slightly low sensitivity in diagnosis of colon cancer (0.87) compared with rectal cancer (0.93).

CONCLUSION

mSEPT9 demonstrated moderate diagnostic value in CRC detection, which was similar to the FIT but superior to the CEA, CA125 and CA199. Combination of mSEPT9 and FIT further improved diagnostic sensitivity in CRC.

TRIAL REGISTRATION

ChiCTR2000038319.

Decitabine and vorinostat with FLAG chemotherapy in pediatric relapsed/refractory AML: Report from the therapeutic advances in childhood leukemia and lymphoma (TACL) consortium

Survival outcomes for relapsed/refractory pediatric acute myeloid leukemia (R/R AML) remain dismal. Epigenetic changes can result in gene expression alterations which are thought to contribute to both leukemogenesis and chemotherapy resistance. We report results from a phase I trial with a dose expansion cohort investigating decitabine and vorinostat in combination with fludarabine, cytarabine, and G-CSF (FLAG) in pediatric patients with R/R AML [NCT02412475]. Thirty-seven patients enrolled with a median age at enrollment of 8.4 (range, 1-20) years. There were no dose limiting toxicities among the enrolled patients, including two patients with Down syndrome. The recommended phase 2 dose of decitabine in combination with vorinostat and FLAG was 10 mg/m2 . The expanded cohort design allowed for an efficacy evaluation and the overall response rate among 35 evaluable patients was 54% (16 complete response (CR) and 3 complete response with incomplete hematologic recovery (CRi)). Ninety percent of responders achieved minimal residual disease (MRD) negativity (<0.1%) by centralized flow cytometry and 84% (n = 16) successfully proceeded to hematopoietic stem cell transplant. Two-year overall survival was 75.6% [95%CI: 47.3%, 90.1%] for MRD-negative patients vs. 17.9% [95%CI: 4.4%, 38.8%] for those with residual disease (p < .001). Twelve subjects (34%) had known epigenetic alterations with 8 (67%) achieving a CR, 7 (88%) of whom were MRD negative. Correlative pharmacodynamics demonstrated the biologic activity of decitabine and vorinostat and identified specific gene enrichment signatures in nonresponding patients. Overall, this therapy was well-tolerated, biologically active, and effective in pediatric patients with R/R AML, particularly those with epigenetic alterations.

Prevention and Treatment of Acute Myeloid Leukemia Relapse after Hematopoietic Stem Cell Transplantation: The State of the Art and Future Perspectives

Allogeneic hematopoietic stem cell transplantation (HSCT) for high-risk acute myeloid leukemia (AML) represents the only curative option. Progress has been made in the last two decades in the pre-transplant induction therapies, supportive care, selection of donors and conditioning regimens that allowed to extend the HSCT to a larger number of patients, including those aged over 65 years and/or lacking an HLA-identical donor. Furthermore, improvements in the prophylaxis of the graft-versus-host disease and of infection have dramatically reduced transplant-related mortality. The relapse of AML remains the major reason for transplant failure affecting almost 40-50% of the patients. From 10 to 15 years ago to date, treatment options for AML relapsing after HSCT were limited to conventional cytotoxic chemotherapy and donor leukocyte infusions (DLI). Nowadays, novel agents and targeted therapies have enriched the therapeutic landscape. Moreover, very recently, the therapeutic landscape has been enriched by manipulated cellular products (CAR-T, CAR-CIK, CAR-NK). In light of these new perspectives, careful monitoring of minimal-residual disease (MRD) and prompt application of pre-emptive strategies in the post-transplant setting have become imperative. Herein, we review the current state of the art on monitoring, prevention and treatment of relapse of AML after HSCT with particular attention on novel agents and future directions.