Proteomic Profiling of Endometriosis and Ovarian Endometrioid Carcinoma: A Preliminary Exploratory Study

IntroductionEndometriosis (EMs) is considered the precursor lesions of ovarian endometrioid carcinoma (OEC). This study aimed to identify differentially expressed proteins between OEC and EMs, and to explore the associated biological functional alterations.Materials and MethodsThis study conducted qualitative and quantitative label-free proteomic analysis on postoperative formalin-fixed paraffin-embedded (FFPE) specimens from 20 patients with EMs and 54 patients with OEC coexisting with EMs. A discovery set was established based on cluster random sampling, and differentially expressed proteins between the two groups were progressively screened. The identified candidates were then validated in an independent test cohort, followed by external validation using public transcriptomic datasets (GSE295399, GSE105764, GSE281569) from the Gene Expression Omnibus (GEO) database.ResultsThe OEC group exhibited a distinct protein expression profile compared to the EMs group. Seven differentially expressed hub proteins (SNRPD1, HNRNPC, NOP58, SRSF6, DHX9, SF3B3, and DHX15) were identified from the discovery cohort, all of which showed significantly altered expression in the test cohort (p < 0.0001). External transcriptomic validation confirmed consistent upregulation for five of the seven hub proteins in OEC compared to EMs (NOP58, SRSF6, DHX9, SF3B3, and DHX15; p < 0.001).ConclusionThis study identified and validated seven differentially expressed proteins associated with RNA splicing in OEC relative to EMs. These findings offer candidate molecules associated with the transition from benign endometriosis to ovarian endometrioid carcinoma; however, further functional studies are required to determine whether they may actively drive malignant transformation.