Normal Breast-Derived Epithelial Cells with Luminal and Intrinsic Subtype-Enriched Gene Expression Document...

Area of Science:

• Oncology
• Cell Biology
• Genetics

Background:

• Cell-type origin influences tumor molecular features, but resources for studying this are limited.
• Previous breast cancer cell line models predominantly yielded basal-type cells.
• Generating diverse normal cell types from adult organs is technically challenging.

Purpose of the Study:

• To create and characterize a panel of immortalized normal breast cell lines representing diverse cell types.
• To validate the concept of cell-type origin impacting tumor characteristics.
• To provide a resource for studying interindividual variations in normal breast tissue.

Main Methods:

• Established immortalized cell lines from core breast biopsies of healthy women.
• Utilized 3D cultures to assess ductal structure formation and marker expression.
• Performed RNA-sequencing (RNA-seq) and PAM50 intrinsic subtype clustering.
• Conducted flow cytometry using markers like CD44/CD24 and CD201/EpCAM.
• Analyzed stemness, differentiation, and signaling pathway activity (NF-κB, AKT2, pERK, BRD4).

Main Results:

• Generated cell lines forming normal-like ductal structures and expressing key transcription factors (ERα-FOXA1-GATA3).
• Identified cell lines as normal counterparts for luminal A, basal, and normal-like breast cancer subtypes.
• Characterized cell lines for stem/basal, progenitor, differentiated, and hybrid cell populations.
• Observed interindividual heterogeneity in stemness, differentiation, and signaling pathway activity.

Conclusions:

• The developed cell lines serve as valuable resources for breast cancer research, particularly for investigating cell-type origin.
• Highlights significant interindividual differences in normal breast tissue.
• Emphasizes the necessity of using diverse normal cell controls to understand cancer-specific genomic aberrations.