Expression profiles of histone modification genes in gastric cancer progression.

Gastric cancer (GC) development can be attributed to several risk factors including atrophic gastritis (AG), intestinal metaplasia (IM), and the presence of Helicobacter pylori (HP). Also, histone modification is an epigenetic mechanism that plays a pivotal role in GC carcinogenesis. In this preliminary study, we aimed to describe the expression profiles of histone modification in the AG, IM, and GC patient groups. A total of 80 patients with AG (n = 27), IM (n = 25), and GC (n = 28) with an additional 20 control subjects were included in the study. Expression profiles of three histone phosphorylation genes (PAK1, NEK6, and AURKA) and five histone deacetylation genes (HDACs 1, 2, 3, 5, and 7) were examined based on the results of Real Time qPCR method. It was observed that AURKA and HDAC2 genes were significantly overexpressed in all groups compared to the control (P < 0.05). In GC patients, overexpression of HDAC2 gene was detected in the absence of metastasis, and overexpression of AURKA, HDAC2, and NEK6 genes was detected in the presence of metastasis. When cancer involvements were compared, significant overexpression of the HDAC2 gene was noted in overall and corpus involvements (P < 0.05). In addition, overexpression of AURKA, NEK6, HDAC1, and HDAC2 genes and underexpression of HDAC5 gene were detected in the antrum involvement (P < 0.05). In conclusion, decreased expression of HDAC5 in GC is reported for the first time in this study, while supporting the existing literature in AURKA, NEK6, HDAC1, and HDAC2 up regulations during GC development.

Overexpressions of RHOA, CSNK1A1, DVL2, FZD8, and LRP5 genes enhance gastric cancer development in the presence of Helicobacter pylori.

BACKGROUND AND STUDY AIMS: Intestinal metaplasia (IM), and Helicobacter pylori (HP) infection can be shown as risk factors in the development of gastric cancer (GC). WNT signaling pathway plays a critical role in carcinogenesis. However, the literature studies are limited on the significance of this pathway for the transition from IM to GC. PATIENTS AND METHODS: We aimed to investigate the importance of the genes of WNT signaling pathways diagnostic and prognostic markers in the presence and absence of HP in conversion from IM to GC. 104 patients, (GC group n = 35, IM group n = 45, control group n = 25) were included in this case-control study. Expression of genes in WNT signalling were searched in study groups with qRT-PCR array and qRT-PCR method. Data were analysed using PCR array data analysis software. RESULTS: Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was detected in the GC and IM groups compared to the control group (p < 0.05). Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was observed in patients with metastatic GC compared to patients with GC without metastasis (p < 0.05). It was found that the RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes were statistically significantly over-expressed in diffuse GC patients compared to non-diffuse GC patients (p < 0.05). Statistically significant overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes was detected in HP positive IM patients compared to HP negative IM patients (p < 0.05). CONCLUSION: Overexpression of RHOA, CSNK1A1, DVL2, FZD8 and LRP5 genes in IM may suggest that these genes are important markers in the development of IM and inflammation with HP. In addition, these genes are linked to tumor burden in the GC group. Consequently, we can conclude that these genes are poor prognosis biomarkers for GC and have the potential to be used as markers for future treatment monitoring.

Potential role of chromatin remodeling factor genes in atrophic gastritis/gastric cancer risk.

BACKGROUND/AIMS: Atrophic gastritis (AG), intestinal metaplasia (IM), and Helicobacter pylori (HP) are the risk factors for the development of gastric cancer (GC). Chromatin remodeling is one of the epigenetic mechanisms involved in the carcinogenesis of GC. The purpose of this study was to investigate the expression profiles of defined chromatin remodeling genes in gastric mucosal samples and their values as gastric carcinogenesis biomarkers. MATERIALS AND METHODS: In total, 95 patients were included in the study. Patients were divided into 3 groups as: GC group (n=34), AG group (n=36), and control group (n=25). AG group was further divided into subgroups based on the presence of HP and IM in gastric mucosa. Chromatin remodeling gene expressions were analyzed using real-time PCR (RT-PCR) array in all groups. Data were evaluated using the RT-qPCR primer assay data analysis software. RESULTS: EED, CBX3, and MTA1 were more overexpressed, whereas ARID1A, ING5, and CBX7 were more underexpressed in the AG and GC groups compared with the controls. No significant differences were observed between the AG and GC groups concerning the expression of these 6 genes, although the fold change levels of these genes in the GC group were well above than in the AG group. EED, CBX3, and MTA1 were significantly more overexpressed in HP- and IM-positive AG subgroup compared with the HP- or IM-negative AG subgroup. CONCLUSION: In conclusion, our results provide an evidence of epigenetic alterations in AG. Expressions of EED, CBX3, MTA1, ARID1A, ING5, and CBX7 may be considered as promising markers to be used in GC screening for patients with AG.