Polo-like Kinase 4: A Molecular Culprit in Skin Cancer Pathogenesis.

Skin cancer remains a significant global health challenge, with rising incidence and associated mortality in late-stage and drug-resistant cases. This underscores a continuing need for more effective novel therapeutic options that can be utilized for efficient management of skin cancers. A promising approach involves exploiting novel targets, which are dysregulated in skin cancer, either alone or in combination with existing therapeutics. Among these, polo-like kinases (PLKs), a family of serine/threonine kinases, has emerged as promising candidates due to their essential role in cell cycle and maintaining genomic stability, key hallmarks of cancer. Within this family, polo-like kinase 4 (PLK4) stands out as a structurally distinct member and the master regulator of centriole duplication, ensuring this process occurs only once per cell division. Dysregulation of PLK4 can disrupt genomic integrity, contributing to tumorigenesis, thus making it a promising target for cancer management. Notably, PLK4 is frequently overexpressed in several cancers, including skin cancer, and its precise role in skin cancer is an area of current investigation. Further, several small-molecule PLK4 inhibitors such as centrinone, YLZ-F5, CFI-400945, and RP-1664 have demonstrated efficacy in targeting PLK4. Among these, CFI-400945 has advanced to clinical trials, where it has shown modest anti-cancer activity. In this review, we provide a comprehensive overview of the known functions of PLK4 in skin cancer. Additionally, we discuss potential mechanistic insights into PLK4's involvement in skin cancer progression by extrapolating evidence from studies in other cancer types including colorectal cancer, thyroid cancer, lymphomas, leukemia, etc., while identifying gaps for future research.