Liquid Biopsy Meets Assembloids: PSA/miRNA/IL in Prostate Cancer

Background: Clinical examination of prostate disorders includes PSA testing, which is organ- but not cancer-specific. MicroRNAs (miRs) contribute to pathological and physiological conditions of many organs. This study investigated PSA, miRs, and interleukins (ILs) and validated findings using prostate cell line-based assembloids. Methods: During a 10-year PSA-based observational study, the expression of miRs (-16, -141, -221, -222, and -375), IL-6, and IL-8 was analyzed in an exploratory cohort using digital PCR and chemiluminescent immunoassays. Prostate assembloids composed of epithelial and fibroblastic cell lines combined with healthy, BPH, or PCa cells were used for in vitro validation. Statistical analyses were performed using Kruskal-Wallis or ANOVA tests and ROC curve analysis. Results: We diagnosed PCa in 19 and BPH in 77 men. PSA and IL-8 levels significantly distinguished PCa from BPH and healthy controls. Serum miR-141 and -222 were reduced in BPH and slightly lower in the PCa group than in the healthy controls. PCa assembloids showed reduced miR-141 and elevated IL-6 and IL-8. ROC analysis showed that miR-141 and miR-222 discriminated BPH from healthy controls (AUCs 0.846 and 0.807), comparable to PSA, whereas PSA performed best for PCa. Conclusions: Our data suggest that miR-141 and miR-222 may complement PSA in prostate disorder diagnostics, showing comparable performance for BPH vs. healthy controls, while PSA performed best for PCa detection. However, given the limited sample size and the lack of external validation, our study should be considered exploratory and requires validation in larger, independent cohorts.