Figure 6

Activation of phosphor-FAK and STAT1 is associated with PAFR in BRCA1 mutant ovarian epithelial cells. (A) The specific phosphorylation of FAK in BRCA1-mutant at-risk HOSE-642 and HOSE-636 cells but not in wild type HOSE-E6E7 cells. (B) Summary of total FAK protein and phosphor-FAK protein induced by PAF treatment in wild type and BRCA1-mutant ovarian epithelial cells. The significant increases (*p < 0.05, **p < 0.01) were compared to the control cells treated with equal volume of DMSO (as 100%). (C) Protein-protein interaction between PAFR and FAK was detected by co-immune precipitation. Antibodies against PAFR and FAK were used for immune precipitation and incubated with protein lysate of HOSE-642 cells with 10 nm PAF treatment, and non-specific IgG was used as negative control. The immune precipitated protein complex was separated on SDS gels and detected by FAK and PAFR antibodies, respectively. (D). Protein-protein interaction between FAK and STAT1 was detected either by immune depletion assay or by co-immune precipitation with phosphor- and non-phospho antibodies of STAT1 and FAK. (E) Simplified scheme to show the integrative signal cascade and activation of PAFR, FAK, and STAT1 as early events of malignant transformation in BRCA1-mutant at-risk ovarian epithelium, particularly under the inflammatory conditions mediated lipid signaling (i.e. PAF).