High Expression of KIF22/Kinesin-Like DNA Binding Protein (Kid) as a Poor Prognostic Factor in Prostate Cancer Patients

Background: Kid (kinesin-like DNA binding protein), a member of microtubule-dependent molecular motor proteins, also known as KIF22, is reported to be associated with carcinogenesis and cancer progression in different types of malignant tumor, but the biologic behavior and clinical outcome of KIF22 in prostate cancer (PCa) has not been well studied. This study aimed to analyze the association between KIF22 and clinical outcome in PCa patients. Material/Methods: The expression of KIF22 in tumor specimens compared with paired paracancerous tissue from 114 patients undergoing radical prostatectomy was detected by immunohistochemistry; results were verified using The Cancer Genome Atlas (TCGA) database. Subsequently, the relationship between KIF22 expression and clinical prognosis of PCa patients was then statistically analyzed. Results: Both immunohistochemistry and database analysis showed that KIF22 was obviously overexpressed in PCa tis- sues compared with paracancerous tissue. The overexpression of KIF22 at the protein level was significantly related to higher clinical stage (P=0.025), Gleason score (P=0.002), seminal vesicle invasion (P=0.007), and lymph node metastasis (P=0.009). Furthermore, with the overexpression of KIF22 mRNA level in PCa patients, the ontological prognosis of PCa patients was much poorer. Conclusions: High-level expression of KIF22 was related to both tumor progression and adverse clinical outcome. For this reason, KIF22 may become a potential prognostic factor for PCa.