Phospho-BRCA1 (Ser1497) Antibody - #AF8204

FIGURE 6. Treatment of Oxaliplatin inhibits HR repair pathways via blocking CDK1-BRCA1 activities in Oxaliplatin resistance cell line. (A) Verification by WB on the effects of Olaparib + Oxaliplatin, Oxaliplatin, Olaparib, AG-02432 and cisplatin on CDK1 expression and its phosphorylation, BRCA1 expression and its phosphorylation, RAD51 expression in SNU719, MKN74, and AGS Oxaliplatin resistance strains. Drug action time was 36 h. (B) Histochemical results of protein phosphorylation in gastric cancer patients. (C,D) The effects of Olaparib + Oxaliplatin and cisplatin combined with CDK1 inhibitor Olaparib on colony formation of overexpressed PARP1 and normally expressed PARP1 cell lines in SNU719, MKN74, and AGS Oxaliplatin resistance strains. Colonies were stained with crystal violet. The Student’s t test was used for statistical analysis. Error bars indicate mean ± standard deviation. OXA, Oxaliplatin. OLP, Olaparib. CON, control group. CISP, cisplatin. PCDK1, CDK1 phosphorylation antibody. PBRCA1, BRCA1 phosphorylation antibody. AGSR, AGS Oxaliplatin resistance. SNU719R, SNU719 Oxaliplatin resistance. MKN74R, MKN74 Oxaliplatin resistance. ∗< 0.05. All experiments were repeated three times.

Fig. 3Induction of HRD with CDK1 inhibition followed by BRCA1 dephosphorylation in HRP ovarian cancer cells. Data are shown as mean ± SD. ***P < 0.001, **P < 0.01, *P < 0.05. (A) BRCA1 phosphorylation was examined in cells treated with PTX or transfected with siRNA CDK1. (B) BRCA1 foci formation in cells treated with PTX was detected by immunofluorescence focal microscopy analysis after γ-irradiation. (C) HR activity in OVISE cells cotransfected with siRNA BRCA1 and BRCA1 variants analyzed by ASHRA. (D) HR activity in PTX-treated OVISE cells cotransfected with siRNA BRCA1 and phosphorylation-mimetic BRCA1 variants analyzed by ASHRA. (E) Reversal of growth inhibition by PTX and olaparib combination treatment by the induction of phosphorylation-mimetic BRCA1 variants.