Investigating Germ Cell Transition Genes in Breast Cancer: Exploring the Genesis of Cancer Testis-Associated Markers

Area of Science:

• Oncology
• Developmental Biology
• Genetics

Background:

• Cellular transition is crucial for tumorigenesis and phenotype development.
• Testis cancer antigens (TCAs) in breast carcinomas hint at potential male germ cell transitions.

Purpose of the Study:

• To investigate breast cancer cells expressing male germ cell development genes.
• To identify germline-associated genes within breast tumors and analyze cellular heterogeneity.

Main Methods:

• Re-analysis of published datasets to identify germline-associated genes.
• Quantitative RT-PCR validation in 28 breast tumor samples.
• Single-cell RNA sequencing (scRNA-seq) for tumor heterogeneity and cell clustering analysis.

Main Results:

• Identified 455 overexpressed genes linked to fetal primordial germ cells (PGCs), especially male gonad PGCs.
• Found significant overexpression of five genes (CCNB1, CCNB2, PTTG1, RACGAP1, UBE2C) in tumor samples.
• scRNA-seq revealed 14 distinct cell clusters with varied gene expression and cell cycle phases; breast tumor stromal cells implicated as the source.

Conclusions:

• Breast cancer exhibits characteristics of male germ cell transition.
• Stromal cells within breast tumors are a likely source of germline-associated genes.
• This study offers insights into molecular pathways of germ cell transition in breast carcinoma.