Suberoyl bis-hydroxamic acid activates Notch1 signaling and induces apoptosis in anaplastic thyroid carcinoma through p53.

Anaplastic thyroid cancer (ATC), usually derived from well-differentiated thyroid cancers is one of the most lethal human endocrine malignancies. In the present study, we report that in human ATC tumor tissue samples exist undetectable Notch1 and the active Notch1 intracellular domain could not be detected in ATC-CAL-62 cells. Interesting, suberoyl bis-hydroxamic acid (SBHA) administration could induce Notch1 intracellular domain levels in a dose-dependent manner, coupled with the increase of p53 and p21. Furthermore, ectopic expression of Notch1 or deletion of p53 with small-interfering RNA was able to abolish the effects of SBHA to elevation of Notch1 and p53 in ATC cells. As a result, SBHA treatment efficiently induced ATC cell apoptosis. These results indicate that SBHA may play antitumor functions via regulating Notch1/p53 signals, and highlight that SBHA could have clinical potential to benefit the therapy of ATC patients.