Altered exosomal miRNA profiles in patients with paraneoplastic cerebellar degeneration.

Objective: Patients with ovarian cancer (OC) may develop anti-Yo-associated paraneoplastic cerebellar degeneration (PCD)-a cerebellar ataxia associated with tumor-induced autoimmunity against CDR2 and CDR2L proteins. Dysregulation of circulating exosomal microRNAs (miRNAs) occur in OC. Here, we investigated whether PCD is associated with changes in the exosomal miRNA profiles of OC patients.

Methods: Serum exosomes were isolated from patients with OC (n = 15), patients with OC and anti-Yo-associated PCD (n = 14) and healthy controls (HC, n = 15). Small RNA sequencing was used to identify differentially expressed miRNAs. Receiver operating characteristic curves were used to evaluate biomarker sensitivity and specificity, and miRNA target prediction analysis was employed to elucidate gene targets.

Results: OC patients with PCD exhibited a distinct exosomal miRNA expression profile. We detected 103 differentially expressed exosomal miRNAs in PCD patients compared to OC patients without PCD and 139 differentially expressed exosomal miRNAs compared to controls. Particularly miR-486-5p, miR-4732-5p, miR-98-5p and miR-21-5p exhibited notable sensitivity and specificity for discriminating PCD patients from both OC patients without PCD and healthy controls. miRNA target prediction showed that several of the differentially expressed miRNAs in PCD patients targeted the CDR2 and CDR2L genes.

Interpretation: Our results demonstrate that OC patients with anti-Yo-associated PCD exhibit a distinct exosomal miRNA profile compared to OC patients without PCD. Several of the differentially expressed exosomal miRNAs in PCD patients showed diagnostic potential and may hold relevance for understanding the pathogenesis of PCD.