Oferta TFM | ID 05

Inactivating germline mutations in a single BRCA2 allele increase the risk of breast and ovarian cancer. Although tumorigenesis typically requires loss of the wild-type allele (loss of heterozygosity, LOH), up to 40% of BRCA2-mutant breast tumors retain it, supporting a role for BRCA2 haploinsufficiency. In these cases, the mutant allele may promote chromosomal instability and facilitate additional alterations that drive transformation. We hypothesize that distinct heterozygous BRCA2 variants differentially influence tumorigenic potential.

To test this, we will perform a genome-wide CRISPR knockout screen in isogenic, non-tumorigenic BRCA2 mut/+ breast epithelial cells (MCF10A), with and without PARP inhibitor (PARPi) treatment, to identify genes that modulate tumorigenesis and PARPi sensitivity. Experiments will be conducted in the Aura Carreira laboratory, with analysis in collaboration with Aleix Bayona-Feliu (Univ. Barcelona).

Top candidate genes will be cross-referenced with datasets from BRCA2-mutant tumors and validated individually in multiple BRCA2-mutant cell lines. Tumorigenic potential will be assessed using soft agar assays and 3D organoid growth.

We expect to identify and validate candidate “second hits” that promote transformation in monoallelic BRCA2-mutant mammary epithelial cells.