MicroRNA expression profiles in non‑epithelial ovarian tumors.

Area of Science:

• Gynecologic Oncology
• Molecular Pathology
• Genomics

Background:

• Ovarian germ cell tumors (OGCTs) and sex cord stromal tumors (SCSTs) are rare gynecologic neoplasms.
• Their molecular pathogenesis remains poorly understood compared to epithelial ovarian cancers.

Purpose of the Study:

• To characterize microRNA (miRNA) expression profiles in OGCTs and SCSTs.
• To identify potential miRNA biomarkers for distinguishing tumor types and malignancy.

Main Methods:

• Small RNA sequencing was used to analyze miRNA expression in 9 OGCTs and 3 SCSTs.
• Quantitative reverse transcription PCR validated miRNA expression in an extended cohort (16 OGCTs, 7 SCSTs).
• Western blot analysis assessed Beclin 1 (BECN1) expression in relation to miRNA levels.

Main Results:

• Significant miRNA expression variations were observed across OGCTs and SCSTs.
• Malignant OGCTs showed higher expression of miR-373-3p, miR-372-3p, miR-302c-3p and lower expression of miR-199a-5p, miR-214-5p, miR-202-3p compared to benign OGCTs or SCSTs.
• SCSTs exhibited higher miR-202c-3p and miR-513c-5p than benign OGCTs. BECN1 expression was elevated in malignant OGCTs, inversely correlating with miR-199a-5p levels.

Conclusions:

• Specific miRNA signatures differentiate OGCTs and SCSTs, and correlate with malignancy in OGCTs.
• These miRNAs hold potential as diagnostic biomarkers for ovarian tumors.
• The findings offer insights into the molecular mechanisms underlying OGCT and SCST development.