3'RNA Sequencing Accurately Classifies Formalin-Fixed Paraffin-Embedded Uterine Leiomyomas

Area of Science:

• Gynecologic Oncology
• Molecular Pathology
• Genomics

Background:

• Uterine leiomyomas are common benign tumors in women of reproductive age.
• Most leiomyomas have specific genetic alterations: MED12 mutations, HMGA2 overexpression, or FH loss.
• Current classification methods are complex, costly, and resource-intensive.

Purpose of the Study:

• To evaluate RNA sequencing as a universal, cost-effective, and scalable method for classifying uterine leiomyomas.
• To determine if RNA sequencing can accurately classify formalin-fixed paraffin-embedded (FFPE) leiomyoma samples.
• To assess the potential of 3'RNA sequencing for leiomyoma subtyping.

Main Methods:

• Performed 3'RNA sequencing on 44 leiomyoma and 5 myometrium FFPE samples.
• Analyzed gene expression patterns to identify leiomyoma subtypes.
• Validated findings using a publicly available fresh-frozen leiomyoma dataset.

Main Results:

• FFPE leiomyoma samples clustered according to the mutation status of MED12, HMGA2, and FH.
• RNA sequencing successfully identified distinct leiomyoma subtypes.
• Results were confirmed in an independent fresh-frozen dataset.

Conclusions:

• Targeted 3'RNA sequencing is a cost-effective and robust tool for stratifying both FFPE and fresh-frozen leiomyomas.
• RNA sequencing offers a promising approach for analyzing archived FFPE tissues in hospital collections.
• This method provides a scalable solution for leiomyoma classification.