ABSTRACT
Monopolar spindle 1, also known as threonine and tyrosine kinase (TTK), is a key component of spindle assembly checkpoint (SAC). It is considered to be a monitoring mechanism to ensure mitotic fidelity and genomic stability. TTK is overexpressed in a variety of malignant tumors, and patients with low expression of TTK tend to have a longer survival time, suggesting that it may be used as a biomarker for diagnosis and prognosis. Abnormal expression of TTK often impairs the function of SAC, resulting in irregular mitosis, increased aneuploidy and mitotic disaster, thus promoting the occurrence of tumors. Current studies have shown that TTK inhibitors can inhibit the proliferation of tumor cells and increase the sensitivity of tumor cells to therapy in combination with chemotherapy or radiotherapy to achieve sensitization and attenuated effects. This article will review the research and application of TTK and its inhibitors in malignant tumors.