Characteristics and prognostic significance of polo‐like kinase‐1 (PLK1) expression in breast cancer

Abstract

AimPolo‐like kinase‐1 (PLK1) plays a crucial role in cell cycle progression, and it is considered a potential therapeutic target in many cancers. Although the role of PLK1 is well established in triple‐negative breast cancer (TNBC) as an oncogene, its role in luminal BC is still controversial. In this study, we aimed to evaluate the prognostic and predictive role of PLK1 in BC and its molecular subtypes.MethodsA large BC cohort (n = 1208) were immunohistochemically stained for PLK1. The association with clinicopathological, molecular subtypes, and survival data was analysed. PLK1 mRNA was evaluated in the publicly available datasets (n = 6774), including The Cancer Genome Atlas and the Kaplan–Meier Plotter tool.Results20% of the study cohort showed high cytoplasmic PLK1 expression. High PLK1 expression was significantly associated with a better outcome in the whole cohort, luminal BC. In contrast, high PLK1 expression was associated with a poor outcome in TNBC. Multivariate analyses indicated that high PLK1 expression is independently associated with longer survival in luminal BC, and in poorer prognosis in TNBC. At the mRNA levels, PLK1 expression was associated with short survival in TNBC consistent with the protein expression. However, in luminal BC, its prognostic value significantly varies between cohorts.ConclusionThe prognostic role of PLK1 in BC is molecular subtype‐dependent. As PLK1 inhibitors are introduced to clinical trials for several cancer types, our study supports evaluation of the pharmacological inhibition of PLK1 as an attractive therapeutic target in TNBC. However, in luminal BC, PLK1 prognostic role remains controversial.

Catalysts of Healing: A Symphony of Synthesis and Clinical Artistry in Small-Molecule Agents for Breast Cancer Alleviation

“…Bromodomain-containing protein 4 (BRD4) regulates gene transcription and has been implicated in breast cancer progression by promoting cell proliferation and survival [ 155 ]. Polo-like kinase 1 (PLK1) plays a crucial role in cell cycle regulation and its overexpression correlates with poor prognosis in breast cancer patients [ 156 ]. Programmed death-ligand 1 (PD-L1) expression on tumor cells enables immune evasion and is being targeted with immunotherapy in breast cancer treatment [ 157 ].…”

Single-cell analyses reveal evolution mimicry during the specification of breast cancer subtype

“…Within the domain of LP subtype breast cancers, PLK1 could function as a potential treatment target warranting further exploration. A recent research reported a molecular subtype-dependent prognostic role of PLK1 in breast cancer 56 . High PLK1 protein expression was remarkably related to a superior prognosis in the whole breast cancer cohort as well as the luminal subtype, but linked with a poor outcome in the triple-negative breast cancer (TNBC) subtype.…”