Published in:
01-02-2019 | Original Article
Methylation Patterns of Lys9 and Lys27 on Histone H3 Correlate with Patient Outcome in Gastric Cancer
Published in: Digestive Diseases and Sciences | Issue 2/2019
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Background
Histone methylation has been considered as one of the epigenetic mechanisms of carcinogenesis and progression. Researches on the correlation between histone lysine methylation and gastric cancer (GC) will help in finding novel epigenetic biomarkers for monitoring cancers.
Aims
The study detected the expression patterns of histone 3 lysine 9 dimethylation (H3K9me2), histone 3 lysine 9 trimethylation (H3K9me3), and histone 3 lysine 27 trimethylation (H3K27me3) in GC tissues and evaluated their clinical merit for GC patients.
Methods
One hundred thirty-three paraffin-embedded GC samples were examined by immunohistochemistry for the histone markers: H3K9me2, H3K9me3, and H3K27me3. The relationship and clinicopathological significance of the three lysine methylations on histone H3 with GC were assessed by Paired t test, Chi-square test, Kaplan–Meier analysis with log-rank test, and Cox proportional hazard analyses.
Results
Strong positive immunostaining of H3K9me2, H3K9me3, and H3K27me3 was observed in cancerous tissues than in their counterpart non-cancer tissues. Higher expression patterns of H3K9me2, H3K9me3, and H3K27me3 significantly related to differentiation degree, lymph nodes metastases, and pathological TNM staging in GC. The GC patients with low scoring of the three markers implied long survival period and best prognosis. In contrast, the patients’ survival time was significantly shorter if their cancerous tissues presented high expression of the three markers.
Conclusions
H3K9me2, H3K9me3, and H3K27me3 expression patterns closely relate to clinicopathological features and may be the independent risk factors for the survival of GC patients. The combined pattern of the three markers rather than an individual marker is considered to more accurately evaluate the outcome of GC patients.