Purpose: Highly expressed in cancer protein 1 (Hec1) is an oncogene and a promising molecular target for novel anticancer drugs. The purpose of this study was to evaluate the potential of a Hec1 inhibitor, TAI-95, as a treatment for primary liver cancer.
Methods: In vitro and in vivo methods were used to test the activity of TAI-95. Gene expression analysis was used to evaluate clinical correlation of the target.
Results: In vitro growth inhibition results showed that TAI-95 has excellent potency on a wide range of primary liver cancer cell lines (hepatoblastoma or hepatocellular carcinoma) (GI(50) 30-70 nM), which was superior to sorafenib and other cytotoxic agents. TAI-95 was relatively inactive in non-cancerous cell lines (GI(50) > 10 μM). TAI-95 disrupts the interaction between Hec1 and Nek2 and leads to degradation of Nek2, chromosomal misalignment, and apoptotic cell death. TAI-95 showed synergistic activity in selected cancer cell lines with doxorubicin, paclitaxel, and topotecan, but not with sorafenib. TAI-95 shows excellent potency in a Huh-7 xenograft mouse model when administered orally. Gene expression analysis of clinical samples demonstrated increased expression of Hec1/NDC80 and associated genes (Nek2, SMC1A, and SMC2) in 27 % of patients, highlighting the potential for using this therapeutic approach to target patients with high Hec1 expression.
Conclusion: Inhibition of Hec1 using small molecule approach may represent a promising novel approach for the treatment of primary liver cancers.