In Silico Assessment of the Structural, Functional and Stability Impact of a Nonsense PRF1 Mutation with Uncertain Clinical Significance; Identified in 2 Unrelated Cypriot Triple-Negative Breast Cancer Patients.

The evolution of Next Generation Sequencing (NGS) technologies represents a significant advancement in the field of molecular genetics and has set the ground, for the discovery of novel variants which cannot be easily classified as deleterious or neutral. In-vitro and in-vivo characterization of these variants of uncertain clinical significance (VUS) should be followed; however, it is often not feasible to carry out the experimental interpretation for every single VUS. In silico tools have been crucial for the prediction of the impact of VUS on protein structure, stability and function. Our aim was to combine computational approaches to investigate the impact of VUS identified in a cohort of Cypriot Triple-Negative Breast Cancer (TNBC) patients by NGS. Using a combination of structural, functional and network-based bioinformatics approaches for the classification of a nonsense PRF1 mutation in association with BC susceptibility, we propose a possible triggered interaction of the mutant PRF1 protein with the CDKN2A protein, a product of a BC susceptibility gene. Additionally, our results support that the increased probability of interaction of the mutant counterpart of perforin with its top 10 predicted interactors, could play an important role in the obstruction of cellular processes related to carcinogenesis such as cell death, necrosis, DNA damage, immortality, UV stress, DNA repair and cell cycle control. We conclude that probably the nonsense PRF1 mutation could be associated with BC predisposition. However, although in silico tools provide an important tool for the interpretation of VUS, functional studies, co-segregation analyses and/or case-control association studies are needed to draw conclusions on variant classification.