HIC1 Expression Distinguishes Intestinal Carcinomas Sensitive to Chemotherapy 12

Neoplastic growth is frequently associated with genomic DNA methylation that causes transcriptional silencing of tumor suppressor genes. We used a collection of colorectal polyps and carcinomas in combination with bioinformatics analysis of large datasets to study the expression and methylation of Hypermethylated in cancer 1 (HIC1), a tumor suppressor gene inactivated in many neoplasms. In premalignant stages, HIC1 expression was decreased, and the decrease was linked to methylation of a specific region in the HIC1 locus. However, in carcinomas, the HIC1 expression was variable and, in some specimens, comparable to healthy tissue. Importantly, high HIC1 production distinguished a specific type of chemotherapy-responsive tumors.