Alteration of histone H3 lysine 9 dimethylation in peripheral white blood cells of septic patients with trauma and cancer

The present study aimed to investigate the clinical significance of histone methylation in sepsis. A total of 43 blood samples from trauma and esophageal cancer patients with or without sepsis were collected. Immunofluorescence staining of isolated peripheral white blood cells (WBCs) was conducted. Co-stained 293T cells served as a reference, to allow the levels of histone methylation in different types of WBCs from patients to be determined. Immunostaining analyses revealed different levels of histone 3 lysine 9 dimethylation (H3K9me2) in neutrophils (Neu), lymphocytes (Lym), and monocytes (Mon) from trauma patients. Compared with trauma patients, the levels of H3K9me2 were elevated in the three types of WBCs from cancer patients. When combined with sepsis, trauma patients demonstrated increased H3K9me2 levels in Neu (P=0.0005) and Mon (P=0.0002), whereas cancer patients had a significant decrease of H3K9me2 levels in the three types of WBCs (Neu, P=0.0003; Lym, P=0.007; Mon, P=0.007). The H3K9me2 alterations in patients with trauma and cancer were different with the occurrence of sepsis. A larger cohort study is warranted to explore the diagnostic significance and prognostic implications of altered histone methylation in septic patients.