Mechanisms of imbalanced testicular homeostasis in infancy due to aberrant histone acetylation in undifferentiated spermatogonia under different concentrations of Di(2-ethylhexyl) phthalate (DEHP) exposure.

Di (2-ethylhexyl) phthalate (DEHP), identified as an endocrine-disrupting chemical, is associated with reproductive toxicity. This association is particularly noteworthy in newborns with incompletely developed metabolic functions, as exposure to DEHP can induce enduring damage to the reproductive system, potentially influencing adult reproductive health. In this study, we continuously administered 40 µg/kg and 80 µg/kg DEHP to postnatal day 5 (PD5) mice for ten days to simulate low and high doses of DEHP exposure during infancy. Utilizing single-cell RNA sequencing (scRNA-seq), our analysis revealed that varying concentrations of DEHP exposure during infancy induced distinct DNA damage response characteristics in testicular Undifferentiated spermatogonia (Undiff SPG). Specifically, DNA damage triggered mitochondrial dysfunction, leading to acetyl-CoA content alterations. Subsequently, this disruption caused aberrations in histone acetylation patterns, ultimately resulting in apoptosis of Undiff SPG in the 40 µg/kg DEHP group and autophagy in the 80 µg/kg DEHP group. Furthermore, we found that DEHP exposure impacts the development and functionality of Sertoli and Leydig cells through the focal adhesion and PPAR signaling pathways, respectively. We also revealed that Leydig cells regulate the metabolic environment of Undiff SPG via Ptn-Sdc4 and Mdk-Sdc4 after DEHP exposure. Finally, our study provided pioneering evidence that disruptions in testicular homeostasis induced by DEHP exposure during infancy endure into adulthood. In summary, this study elucidates the molecular mechanisms through which DEHP exposure during infancy influences the development of testicular cell populations.

DNA methylation landscape reveals GNAS as a decitabine-responsive marker in patients with acute myeloid leukemia.

BACKGROUND: The demethylation agent decitabine (DAC) is a pivotal non-intensive alternative treatment for acute myeloid leukemia (AML). However, patient responses to DAC are highly variable, and predictive biomarkers are warranted. Herein, the DNA methylation landscape of patients treated with a DAC-based combination regimen was compared with that of patients treated with standard chemotherapy to develop a molecular approach for predicting clinical response to DAC. METHODS: Twenty-five non-M3 AML patients were enrolled and subjected to DNA methylation sequencing and profiling to identify differentially methylated regions (DMRs) and genes of interest. Moreover, the effects of a DAC-based regimen on apoptosis and gene expression were explored using Kasumi-1 and K562 cells. RESULTS: Overall, we identified 541 DMRs that were specifically responsive to DAC, among which 172 DMRs showed hypomethylation patterns upon treatment and were aligned with the promoter regions of 182 genes. In particular, GNAS was identified as a critical DAC-responsive gene, with in vitro GNAS downregulation leading to reduced cell apoptosis induced by DAC and cytarabine combo treatment. CONCLUSIONS: We found that GNAS is a DAC-sensitive gene in AML and may serve as a prognostic biomarker to assess the responsiveness of patients with AML to DAC-based therapy.

DNA methylation landscape reveals LIN7A as a decitabine-responsive marker in patients with t(8;21) acute myeloid leukemia.

BACKGROUND: Despite its inconsistent response rate, decitabine, a demethylating agent, is often used as a non-intensive alternative therapeutic agent for acute myeloid leukemia (AML). It has been reported that relapsed/refractory AML patients with t(8;21) translocation achieved better clinical outcomes with a decitabine-based combination regimen than other AML subtypes; however, the mechanisms underlying this phenomenon remain unknown. Herein, the DNA methylation landscape of de novo patients with the t(8;21) translocation was compared with that of patients without the translocation. Moreover, the methylation changes induced by decitabine-based combination regimens in de novo/complete remission paired samples were investigated to elucidate the mechanisms underlying the better responses observed in t(8;21) AML patients treated with decitabine. METHODS: Thirty-three bone marrow samples from 28 non-M3 AML patients were subjected to DNA methylation sequencing to identify the differentially methylated regions and genes of interest. TCGA-AML Genome Atlas-AML transcriptome dataset was used to identify decitabine-sensitive genes that were downregulated following exposure to a decitabine-based regimen. In addition, the effect of decitabine-sensitive gene on cell apoptosis was examined in vitro using Kasumi-1 and SKNO-1 cells. RESULTS: A total of 1377 differentially methylated regions that specifically responsive to decitabine in t(8;21) AML were identified, of which 210 showed hypomethylation patterns following decitabine treatment aligned with the promoter regions of 72 genes. And the methylation-silencing genes, LIN7A, CEBPA, BASP1, and EMB were identified as critical decitabine-sensitive genes in t(8;21) AML. Moreover, AML patients with hypermethylated LIN7A and reduced LIN7A expression had poor clinical outcomes. Meanwhile, the downregulation of LIN7A inhibited decitabine/cytarabine combination treatment-induced apoptosis in t(8;21) AML cells in vitro. CONCLUSION: The findings of this study suggest that LIN7A is a decitabine-sensitive gene in t(8;21) AML patients that may serve as a prognostic biomarker for decitabine-based therapy.

Genomic analysis of mutations in platelet mitochondria in a case of benzene-induced leukaemia: A case report.

INTRODUCTION: As a hematopoietic carcinogen, benzene induces human leukemia through its active metabolites such as benzoquinone, which may cause oxidative damage to cancer-related nuclear genes by increasing reactive oxygen species (ROS). Mitochondrion is the main regulatory organelle of ROS, genetic abnormality of mitochondrion can impede its regulation of ROS, leading to more severe oxidative damage. Mutations have been related to certain types of cancer in several mitochondrial genes, but they have never been completely analyzed genome-wide in leukemia. PATIENT CONCERNS: The patient was a 52-year-old female who had chronic exposure to benzene for several years. Her symptoms mainly included recurrent dizziness, fatigue, and they had lasted for nearly 8 years and exacerbated in recent weeks before diagnosis. DIAGNOSIS: Samples of peripheral blood were taken from the patient using evacuated tubes with EDTA anticoagulant on the second day of her hospitalization. At the same time blood routine and BCR/ABL genes of leukemic phenotype were tested. Platelets were isolated for mitochondrial DNA (mtDNA) extraction. The genetic analysis of ATP synthase Fo subunit 8 (complex V), ATP synthase Fo subunit 6 (complex V), cytochrome c oxidase subunit 1 (complex IV), cytochrome c oxidase subunit 2 (complex IV), cytochrome c oxidase subunit 3, Cytb, NADH dehydrogenase subunit 1 (complex I) (ND) 1, ND2, ND3, ND4, ND5, ND6, 12S-RNA, 16S-RNA, tRNA-Cysteine, A, N, tRNA-Leucine, E, displacement loop in platelet mtDNA were performed. All the detected gene mutations were validated using the conventional Sanger sequencing method. INTERVENTIONS: The patient received imatinib, a small molecule kinase inhibitor, and symptomatic treatments. OUTCOMES: After 3 months treatment her blood routine test indicators were restored to normal. CONCLUSION: A total of 98 mutations were found, and 25 mutations were frame shift. The ND6 gene mutation rate was the highest among all mutation points. Frame shifts were identified in benzene-induced leukemia for the first time. Many mutations in the platelet mitochondrial genome were identified and considered to be potentially pathogenic in the female patient with benzene-induced leukemia. The mutation rate of platelet mitochondrial genome in the benzene-induced leukemia patient is relatively high, and the complete genome analysis is helpful to fully comprehend the disease characteristics.