Abstract
BACKGROUND: H3.3 histone is a replacement histone subtype that is express in entire cell cycle phases and overexpress in transcriptionally active regions, promoter regions, and intergenic or intragenic regulatory elements. This histone encoded by two genes termed H3.3A (H3F3A) and H3.3B (H3F3B). Mutations of these two genes lead to some human cancers such as chondroblastoma, osteosarcoma, and epithelial ovarian cancer. The aims of this study were to quantitatively examine the expression of H3.3B gene in colorectal cancer (CRC) and to correlate their expression level with demographics and clinicopathological characteristics. METHODS: We investigated H3.3B gene expression in CRC by relative quantitative real-time polymerase chain reaction (real-time PCR) technique for the first time. For this purpose, total RNA extracted, then cDNA synthesized and H3.3B gene expression was evaluated with specific primers by real-time PCR in tumoral tissues and adjacent normal tissues of 36 patients with CRC, then statistical analysis was performed using SPSS software. RESULTS: The results of this study indicated that H3.3B gene significantly overexpressed in tumoral tissue than adjacent normal tissue. Furthermore, statistical analysis represented the significant correlation between the H3.3B gene expression and some of the clinicopathological characteristics. CONCLUSIONS: Our study showed that H3.3B gene expression changes can be useful as a probable prognosis biomarker in the early stages of CRC before it metastasized.