PLK1 as a cooperating partner for BCL2-mediated antiapoptotic program in leukemia

The deregulation of BCL2 family proteins plays a crucial role in leukemia development. Therefore, pharmacological inhibition of this family of proteins is becoming a prevalent treatment method. However, due to the emergence of primary and acquired resistance, efficacy is compromised in clinical or preclinical settings. We developed a drug sensitivity prediction model utilizing a deep tabular learning algorithm for the assessment of venetoclax sensitivity in T-cell acute lymphoblastic leukemia (T-ALL) patient samples. Through analysis of predicted venetoclax-sensitive and resistant samples, PLK1 was identified as a cooperating partner for the BCL2-mediated antiapoptotic program. This finding was substantiated by additional data obtained through phosphoproteomics and high-throughput kinase screening. Concurrent treatment using venetoclax with PLK1-specific inhibitors and PLK1 knockdown demonstrated a greater therapeutic effect on T-ALL cell lines, patient-derived xenografts, and engrafted mice compared with using each treatment separately. Mechanistically, the attenuation of PLK1 enhanced BCL2 inhibitor sensitivity through upregulation of BCL2L13 and PMAIP1 expression. Collectively, these findings underscore the dependency of T-ALL on PLK1 and postulate a plausible regulatory mechanism.

Automated summary

Deregulation of BCL2 family proteins is critical in leukemia development, and inhibiting these proteins has become a common treatment for the disease. However, resistance to this treatment has compromised its effectiveness. In this study, a drug sensitivity prediction model was developed to assess the sensitivity of T-cell acute lymphoblastic leukemia (T-ALL) patients to the drug venetoclax. The results showed that PLK1 is a cooperating partner for the BCL2-mediated antiapoptotic program, and concurrent treatment using venetoclax and PLK1 inhibitors demonstrated a greater therapeutic effect on T-ALL.