Relationship between the protein expression of ARID1A, ARID1B and ARID2 with the clinicopathological characteristics of colorectal cancer.

The SWitch/sucrose non-fermentable chromatin remodeling complex functions as a tumor suppressor by regulating gene expression and thus various cellular processes. Key subunits of this complex, including the AT-rich interactive domain (ARID)-containing proteins ARID1A, ARID1B and ARID2, are frequently mutated in cancer, including colorectal cancer (CRC). However, their protein expression and prognostic significance in CRC remain unclear. The present study investigated the ARID1A, ARID1B and ARID2 expression levels in CRC tissues and their relationship with the clinicopathological characteristics of patients. Bioinformatics analysis of The Cancer Genome Atlas-colon adenocarcinoma cohort revealed frequent mutations, positive mRNA correlations among the ARID genes and increased promoter methylation levels. Immunohistochemical analysis of 63 CRC tissue samples demonstrated significantly decreased ARID1A, ARID1B and ARID2 protein expression in cancerous areas compared with adjacent non-cancerous areas of the tissues. Low ARID1A and ARID1B expression levels were significantly associated with advanced clinicopathological characteristics in Thai patients with CRC. All three ARIDs showed a trend towards an association with the 5-year progression-free survival of Thai patients with CRC. Kaplan-Meier plotter database analysis further demonstrated that low expression of all three ARID genes was associated with a shorter overall survival time in patients with CRC; however, only ARID1A expression showed a statistically significant prognostic relevance. In conclusion, the ARID1A, ARID1B and ARID2 expression levels were shown to be positively correlated, and their reduced expression was associated with worse clinicopathological characteristics in patients with CRC. These findings suggest the potential of ARIDs as prognostic biomarkers, warranting further investigation to validate their clinical significance.