Although the pooled results demonstrated that BAP1 mutation was a negative indicator of overall survival (hazard ratio = 1.73; 95% confidence interval = 1.23-2.42) and disease-free survival (hazard ratio = 2.25; 95% confidence interval = 1.47-3.45), this prognostic value was only applicable to uveal melanoma and clear cell renal cell carcinoma, but not to malignant pleural mesothelioma or cholangiocarcinoma.
Recent work has focused on the frequent somatic inactivation of two tumor suppressor genes in MPM-NF2 (Neurofibromatosis type 2) and the recently identified BAP1 (BRCA associated protein 1).
Recent reports have also focused upon germline mutations in the BRCA1-associated protein 1 (BAP1), not only in cases of familial mesothelioma, but also BAP1 deletion in sporadic MM.
Here we report mRNA splicing analysis on a homozygous substitution mutation, BAP1 c. 2054 A&T (p.Glu685Val), identified in an MPM cell line derived from a mesothelioma patient.
The top hypomethylated single-CpG (cases versus controls effect size less than -0.15, p<sub>fdr</sub> < 0.05 in both the training and test sets) was detected in FOXK1 (Forkhead-box K1) gene, an interactor of BAP1 which was found mutated in MPM tissue and as germline mutation in familial MPM.
Assessment of the frequency and pattern of BAP1 gene mutations in Egyptian patients with advanced sporadic MPM in relation to disease progression and survival rates in order to identify a novel therapeutic target for MPM.
We report here a new pathogenic germline variant in BAP1: c.783 + 2 T > C. The prevalence of pathogenic germline variants in BAP1 was 7.7% among patients with familial MPM (3/39).
Taking into account previous similar screenings, the prevalence of germline BAP1 mutations in sporadic MPM patients can be estimated around 1-2%, suggesting a minor role of germline BAP1 mutation in the pathogenesis of sporadic MPM.
We examined the expression of the 9p21.3-related proteins (p14, p15, p16, and methylthioadenosine phosphorylase (MTAP)) and BAP1 using IHC in 51 MPM and 25 RMH cases, and assessed their correlation with HD of p16 detected by FISH.
CCDC6 (coiled-coil domain containing 6) is a player of the HR response to DNA damage and has been predicted to interact with BAP1, another HR-DNA repair gene highly mutated in Malignant Pleural Mesothelioma (MPM), an aggressive cancer with poor prognosis.
Identification of BRCA1-associated protein 1 (BAP1) and cyclin-dependent kinase inhibitor 2A (CDKN2A) gene mutations in MPM have led to the development of new ancillary tests that can streamline the diagnostic pathway.
Negative nuclear staining for BAP1 occurred in 62% of MPMs (including 27% with a cytoplasmic pattern) and was significantly associated with the presence of BAP1 mutation, epithelioid subtype, and a better prognosis.
A series of 123 formalin-fixed, paraffin-embedded tissue samples with clinical annotations were retrospectively tested with a commercial library kit (Ion AmpliSeq Cancer Hotspot Panel v.2, Life Technologies, Grand Island, NY) to investigate 50 genes plus other two, BRCA1-associated protein-1 (BAP-1) and neurofibromatosis-2 (NF2), frequently altered in MPM.
Whereas recent epidemiological data demonstrated that the incidence of MPM-related death continued to increase in United States between 2009 and 2015, new insight into the molecular pathogenesis and the immunological tumor microenvironment of MPM, for example, regarding the role of BRCA1 associated protein 1 and the expression programmed death receptor ligand 1, are highlighting new potential therapeutic strategies.
Our observations reveal a potential clinical application where BAP1 status could serve as predictive or stratification biomarker for RNR inhibition-based therapy in MPM.