Targeting DNA methyltransferases for cancer therapy

Molecular mechanistic approach to reveal decitabine's effect on DNMT gene modulation and its inhibitory role in heavy metal-induced proliferation in urinary bladder cancer cell line

Heavy metals are pervasive environmental and occupational carcinogens known to induce uncontrolled cell proliferation. They influence a number of cellular processes, including proliferation, metabolism, apoptosis, and carcinogenesis. Among the several underlying mechanisms of carcinogenesis, metal-induced aberrant modulation of DNA methyltransferase (DNMT) activity may play crucial role. In this context, our study explored the proliferative and/or cytotoxic effects of heavy metals on the T24 urinary bladder cancer cell line. Additionally, we evaluated the effects of heavy metals and the chemotherapeutic agent decitabine on DNMT expression and activity. For investigative purposes, T24 cells were exposed to different heavy metals; namely, lead (Pb), chromium (Cr), cadmium (Cd), nickel (Ni), and arsenic (As) at concentrations ranging from 0.5 to 32 μM for 24, 48, and 72 h, as well as to decitabine (1 to 64 μM) for 72 h. Post-incubation, cell proliferation and migration increased, and mitochondrial membrane potential decreased significantly in the presence of heavy metals, especially Cr and Cd. Moreover, in the presence of Cr and Cd, expression of DNMT1 and DNMT3b genes enhanced significantly. Furthermore, decitabine treatment effectively inhibited Cd- and Cr-induced proliferation and downregulated expression of DNMT genes. In conclusion, heavy metals such as Cd and Cr may contribute to urinary bladder carcinogenesis through DNMT upregulation, while decitabine showedprotective effects by suppressing DNMT expression and inhibiting cell proliferation.

DNA methylation modification: Dawn of research on cornea-related diseases

DNA methylation is a significant form of epigenetic modification that plays a crucial role in the occurrence and progression of diseases by regulating gene expression. Recent advancements in our understanding of DNA methylation have demonstrated its involvement in corneal damage repair and various corneal diseases. This article reviews the mechanisms and effects of DNA methylation modifications in corneal injury repair, keratoconus, corneal dystrophy, keratitis, and other related conditions. The aim is to enhance our understanding of the vital role of DNA methylation in the pathogenesis of corneal injuries and the development of cornea-related diseases. The phenomenon of DNA methylation in these conditions may offer new ideas and insights for therapeutic approaches.

Therapeutic Potential of Tricyclic Pyridazinone-Based Molecules: An Overview

Pyridazin-3(2H)one-based molecules have always attracted the attention of medicinal chemists due to their different pharmacological properties. The incorporation of such nuclei in therapeutically active molecules either as monocyclic units or as fused bi- or tricyclic scaffolds results in a wide range of pharmacological effects such as anti-inflammatory, analgesic, anticancer, antimicrobial, antiviral, cardiovascular-protective, antiulcer, and many other useful pharmacological activities. In accordance with our consolidated experience gained over the years in the chemistry and biology of tricyclic pyridazin-3(2H)ones, this review summarizes SAR studies of such pyridazinone-based polycyclic compounds endowed with various biological and therapeutic properties.

LINC02167 stabilizes KSR1 mRNA in an m5C-dependent manner to regulate the ERK/MAPK signaling pathway and promotes colorectal cancer metastasis

BACKGROUND

Metastasis is a leading cause of colorectal cancer (CRC)-related mortality, yet its molecular mechanisms remain poorly understood. Long noncoding RNAs (lncRNAs) have emerged as critical regulators of CRC metastasis, but their specific roles are not fully elucidated. This study identifies and characterizes a novel lncRNA LINC02167 as a critical regulator of CRC metastasis.

METHODS

LINC02167 expression was analyzed in CRC tissues via real-time quantitative polymerase chain reaction and fluorescence in situ hybridization. Functional assays evaluated its role in CRC cell migration, invasion, and metastasis in vitro and in vivo. Mechanistic exploration involves a combination of techniques, including RNA sequencing, mass spectrometry, RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, luciferase reporter assays, RNA stability assays, and bioinformatics analysis, to uncover the molecular interactions and pathways regulated by LINC02167.

RESULTS

LINC02167 is markedly upregulated in CRC tissues and strongly correlates with advanced clinical features and poor prognosis. Functional analyses reveal that LINC02167 enhances CRC cell migration and invasion in vitro and promotes metastasis in vivo. Mechanistically, LINC02167 serves as a molecular scaffold, forming a complex with YBX1 and ILF3 to facilitate YBX1 binding to NSUN2-mediated m5C modification sites on KSR1 mRNA, thereby stabilizing KSR1 mRNA and activating the ERK/MAPK signaling pathway to drive CRC metastasis. Additionally, MYC-driven transcriptional activation leads to the upregulation of LINC02167 in CRC.

CONCLUSIONS

This study uncovers a novel mechanism through which LINC02167 promotes the ERK/MAPK pathway and CRC metastasis via m5C modification, underscoring its potential as a promising therapeutic target for metastatic CRC treatment.

A phase 2 study of chidamide in combination with CAG and venetoclax-azacitidine in acute myeloid leukemia: Clinical safety, efficacy, and correlative analysis

Acute myeloid leukemia (AML) is a highly heterogeneous hematopoietic malignancy characterized by elevated mortality. Epigenetic therapy plays an essential role in the treatment of AML. However, the clinical outcomes of the combination of multiple epigenetic agents and conventional chemotherapy remain unclear. We conducted a phase 2 study to evaluate the clinical safety and efficacy of chidamide combined with CAG and venetoclax-azacitidine (referred to as CACAG-VEN) in AML patients (NCT05659992). Patients received induction treatment with aclarubicin (10 mg/m2/d on days 1, 3, and 5), azacitidine (75 mg/m2 on days 1-7), cytarabine (75 mg/m2 bid on days 1-5), chidamide (30 mg, twice/week for 2 weeks), and venetoclax (100 mg on day 1, 200 mg on day 2, 400 mg on days 3-14). Granulocyte colony-stimulating factor 5 μg/kg/day was administered. After one cycle of CACAG-VEN, the overall response rate was 96.7 %, with a composite complete response (CRc) rate of 93.3 %. The CRc rates (86.7 %) were remarkable among patients with adverse NCCN risk. Patients receiving two cycles of CACAG-VEN achieved a CRc rate of 100 %. The 12-month overall survival rate was 69.7 %. The median time to recovery was 19 days for platelets ≥50,000/μL and 17 days for an absolute neutrophil count ≥500 cells/μL after induction therapy. The single-cell RNA sequence showed most immune cells exhibited no significant change in proportion after removing tumor cells. In conclusion, this regimen resulted in a high CRc rate in newly diagnosed AML patients, particularly in adverse-risk patients. And this regimen had minimal impact on immune cells.

5-Aza combined with VPA reprograms human T lineage acute leukemia Jurkat cells into B-cell-like cells by epigenetic activation of PAX5

Epigenetic regulation plays an important role in cell fate reprogramming. Here, we found that inhibitors of epigenetic modifiers, including VPA, TSA, and 5-Aza-2'-deoxycytidine, can induce phenotypic transformation from Jurkat cells into B-cell-like cells. When Jurkat cells were treated with 5-Aza combined with VPA, B cell and stem cell marker expression was observed. These gene expression pattern changes were most remarkable in the optimized B cell induction conditions provided by the cocultured and genetically modified murine bone marrow OP9 cells. In such conditions, Jurkat cells were endowed with the ability to secrete B cell cytokines, and B lymphocyte-related genes and pathways were activated. In studying the mechanism underlying Jurkat cell reprogramming by 5-Aza and VPA, we found that PAX5, the key transcription factor regulating B cell development, was significantly upregulated. Treatment with 5-Aza and VPA inhibited the methylation of CpG islands and upregulated the acetylated H3K9 modification in the PAX5 promoter region, respectively, thus epigenetically activating the expression of PAX5 and promoting the reprogramming of Jurkat cells. Similar reprogramming results were also observed in primary CD4+T cells following treatment with 5-Aza and VPA. Our results provide a de novo paradigm for the reprogramming of T cells through epigenetic modifications.

The Role of the DNA Methyltransferase Family and the Therapeutic Potential of DNMT Inhibitors in Tumor Treatment

Members of the DNA methyltransferase (DNMT) family have been recognized as major epigenetic regulators of altered gene expression during tumor development. They establish and maintain DNA methylation of the CpG island of promoter and non-CpG region of the genome. The abnormal methylation status of tumor suppressor genes (TSGs) has been associated with tumorigenesis, leading to genomic instability, improper gene silence, and immune evasion. DNMT1 helps preserve methylation patterns during DNA replication, whereas the DNMT3 family is responsible for de novo methylation, creating new methylation patterns. Altered DNA methylation significantly supports tumor growth by changing gene expression patterns. FDA-approved DNMT inhibitors reverse hypermethylation-induced gene repression and improve therapeutic outcomes for cancer. Recent studies indicate that combining DNMT inhibitors with chemotherapies and immunotherapies can have synergistic effects, especially in aggressive metastatic tumors. Improving the treatment schedules, increasing isoform specificity, reducing toxicity, and utilizing genome-wide analyses of CRISPR-based editing to create personalized epigenetic therapies tailored to individual patient needs are promising strategies for enhancing therapeutic outcomes. This review discusses the interaction between DNMT regulators and DNMT1, its binding partners, the connection between DNA methylation and tumors, how these processes contribute to tumor development, and DNMT inhibitors' advancements and pharmacological properties.

Implication of protein post translational modifications in gastric cancer

Gastric cancer (GC) is one of the most common and highly lethal malignant tumors worldwide, and its occurrence and development are regulated by multiple molecular mechanisms. Post-translational modifications (PTM) common forms include ubiquitylation, phosphorylation, acetylation and methylation. Emerging research has highlighted lactylation and glycosylation. The diverse realm of PTM and PTM crosstalk is linked to many critical signaling events involved in neoplastic transformation, carcinogenesis and metastasis. This review provides a comprehensive overview of the impact of PTM on the occurrence and progression of GC. Specifically, aberrant PTM have been shown to alter the proliferation, migration, and invasion capabilities of GC cells. Moreover, PTM are closely associated with resistance to chemotherapeutic agents in GC. Notably, this review also discusses the phenomenon of PTM crosstalk, highlighting the interactions among PTM and their roles in regulating signaling pathways and protein functions. Therefore, in-depth investigation into the mechanisms of PTM and the development of targeted therapeutic strategies hold promise for advancing early diagnosis, treatment, and prognostic evaluation of GC, offering novel insights and future research directions.