News
Making breast cancer cells more visible to the immune system
Published on December 15, 2025
The team led by Pierre Thibault, Director of IRIC’s Proteomics and Mass Spectrometry Research Unit, has discovered that abemaciclib, used to treat hormone receptor-positive metastatic breast cancer, reprograms the antigenic profile of tumors—a characteristic that could be exploited to improve treatment efficacy. Led by doctoral student Robin Minati, this study has just been published in the journal Cell Reports. It is the result of a close collaboration with the team of Claude Perreault, Director of IRIC’s Immunobiology Research Unit.
The team led by Pierre Thibault, Director of IRIC’s Proteomics and Mass Spectrometry Research Unit, has discovered that abemaciclib, used to treat hormone receptor-positive metastatic breast cancer, reprograms the antigenic profile of tumors—a characteristic that could be exploited to improve treatment efficacy. Led by doctoral student Robin Minati, this study has just been published in the journal Cell Reports. It is the result of a close collaboration with the team of Claude Perreault, Director of IRIC’s Immunobiology Research Unit.
Abemaciclib “opens up” certain regions of DNA
Using a proteogenomic approach, researchers observed that treatment with abemaciclib increases the presentation and diversity of protein fragments, called tumor antigens, on the surface of breast cancer cells. This effect is particularly pronounced in hormone receptor-positive (HR+) breast cancer cells.
Where do these new antigens come from? The work of the Thibault laboratory shows that they derive from regions of DNA previously thought to be non-coding. Under the effect of abemaciclib on key regulatory proteins, such as retinoblastoma (Rb) and BET proteins, these regions become accessible to the cellular machinery and can then give rise to new antigens.
Increasing immune recognition of tumors
The new antigens produced by abemaciclib treatment trigger an immune response and are poorly expressed in healthy tissue. They therefore represent ideal targets for the development of more specific immunotherapies. By combining abemaciclib with immunotherapy approaches, it may be possible to make HR+ tumors more visible to the immune system and strengthen the antitumor immune response. This approach could also be extended to other types of cancer, particularly those regulated by Rb and BET proteins.
Cited study
Minati R, Cahuzac M, Perrault J, Lullier V, Apavaloaei A, Bonneil E, Courcelles M, Lanoix J, Kina E, Perreault C, Thibault P. CDK4/6 inhibition reprograms the breast cancer immunopeptidome via Rb-dependent chromatin and transcriptomic remodeling. Cell Rep. 2025 Dec 12;44(12):116676. doi: 10.1016/j.celrep.2025.116676.
