Polo-like kinase 1 Decrease During Induction Therapy Could Indicate Good Treatment Response, Favorable Risk Stratification, and Prolonged Survival in Pediatric Acute Lymphoblastic Leukemia.

OBJECTIVE: Polo-like kinase 1 (PLK1) modulates leukemia cell apoptosis, proliferation, and cell cycle arrest in the progression of acute lymphoblastic leukemia (ALL). This study intended to investigate the dysregulation of PLK1 and its association with induction therapy response and prognosis in pediatric ALL patients.

MATERIALS AND METHODS: Bone marrow mononuclear cell samples were collected from 90 pediatric ALL patients at baseline and on the 15th day of induction therapy (D15), as well as from 20 controls after enrollment, for the detection of PLK1 by reverse transcription-quantitative polymerase chain reaction.

RESULTS: PLK1 was increased in pediatric ALL patients compared with controls (P<0.001). In pediatric ALL patients, PLK1 decreased from baseline to D15 (P<0.001). Lower PLK1 at baseline was associated with a good prednisone response (P=0.002), while decreased PLK1 at D15 was related to good prednisone response (P=0.001), better bone marrow response (P=0.025), and favorable risk stratification (P=0.014). In addition, reduced PLK1 at baseline was linked with better event-free survival (EFS) (P=0.046), and decreased PLK1 at D15 was related to prolonged EFS (P=0.027) and overall survival (OS) (P=0.047). Moreover, PLK1 decline ≥25% was linked to favorable EFS (P=0.015) and OS (P=0.008). Further multivariate Cox proportional regression analysis revealed that PLK1 decline ≥25% was independently linked with prolonged EFS (hazard ratio (HR)=0.324, P=0.024) and OS (HR=0.211, P=0.019).

CONCLUSION: The reduction of PLK1 after induction therapy reflects a good treatment response and correlates with a favorable survival profile in pediatric ALL patients.