CL-43, a New Inhibitor of HSF1 Activity, Inhibits Epithelial-Mesenchymal Transition of DLD1 Colon Cancer Cells

Abstract

Colorectal cancer is highly metastatic. In a quarter of patients with tumors of this type, liver metastases are detected already at the time of diagnosis. Therefore, the search for drugs that can reduce the metastatic activity of cells is an important task. A tumor experiences constant stress, resulting in an increased activity of the transcription factor HSF1, which is able to trigger the synthesis of heat shock proteins. This increases the resistance of cancer cells to both stress and antitumor therapy. It has been shown recently that HSF1 plays a critical role in the process of the epithelial–mesenchymal transition (EMT) underling the formation of metastases. Here, we show that a new inhibitor of HSF1 activity, CL-43, is capable of suppressing EMT that is induced by TGFβ1. CL-43 significantly reduced the migration and proliferative potency of DLD1 cells treated with TGFβ1. Analysis of vimentin level showed that cell treatment with CL-43 cells reduced this EMT marker and returned the expression and localization of E-cadherin in the cells to the original pattern. These findings suggest that CL-43 has therapeutic potential for treatment of colorectal tumors.