RHBDD2: a 5-fluorouracil responsive gene overexpressed in the advanced stages of colorectal cancer.

In previous studies, we identified rhomboid domain containing 2 (RHBDD2) gene to be markedly overexpressed in breast cancer patients that developed recurrence of the disease. In this study, we evaluated for the first time RHBDD2 gene expression in colorectal cancer (CRC). Five public available DNA microarray studies were compiled in a homogeneous dataset of 906 colorectal samples. The statistical analysis of these data showed a significant increase of RHBDD2 expression in the advanced stages of CRC (p < 0.01). We validated these findings by immunohistochemistry on 130 colorectal tissue samples; RHBDD2 protein overexpression was also observed in the advanced stages of the disease (p < 0.001). In addition, we investigated RHBDD2 expression in response to the chemotherapy agent 5-fluorouracile (5FU). We detected a significant increase of RHBDD2 mRNA and protein after 5FU treatment (20-40 μM; p < 0.001). Overall, these results showed that RHBDD2 overexpression might play a role in colorectal cancer progression.