Fig 2: Fangchinoline enhances cisplatin efficacy in ovarian cancer cells. Aurora A expression was observed in cisplatin-treated ovarian cancer cells. The ovarian cancer cell lines OVCAR-3, SK-OV-3, ES-2, and MDAH 2774 were treated with 10 µM cisplatin for 48 h, and Aurora A expression was detected by Western blotting (A). The quantification of the Aurora A expression (B). To investigate the effects of fangchinline treatment on cisplatin–DNA adduct formation in ovarian cancer cells, OVCAR-3 cells were treated with fangchinoline and cisplatin (CIS; 10 µM) for 48 h, and cisplatin–DNA adduct levels were detected using an anti-cisplatin-modified DNA antibody, followed by flow cytometry. Data are presented as the mean ± SD (n = 3). *** p < 0.001 compared to cisplatin group (C).

Fig 3: PP1, PPP1R2, pR2, and AURKA are localized at the midbody. a ARPE-19 cells were fixed and stained for the indicated endogenous proteins (green) localized relative to α-tubulin of the central spindle (red). b Average intensity from the green channel along the central spindle was measured in 10–0.87 μm2 square regions spanning the length of the central spindle in 30 dividing cells and is plotted in (c). Size bar equals 5 μm. Asterisks indicate statistical significance compared to control (*p ≤ 0.001, **p ≤ 0.001) and error bars represent standard error of the mean

Fig 4: Protein detection in tumor tissue. Tumors were collected on Day22. Aurora A activation was observed by detecting Aurora A and phospho (p)-Aurora A protein expressions in tumor tissue (A). Apoptosis and proliferation were evaluated by detecting cleaved caspase 3 and Ki67 protein expressions, respectively (B). Immunohistochemical staining was performed. Proteins were observed with brown staining. Original magnification, ×100. Scale bar: 200 µm.

Fig 5: PPP1R2 interaction with both PP1 and AURKA affects centrosome number and is phosphorylation dependent. a Schematics of the PPP1R2 mutants used for transfection. The left schematic shows the position of phosphorylation site mutants involving the Thr73 residue including both the threonine to alanine phosphonull mutation PPP1R2A (R2A) and threonine to glutamic acid phosphomimetic mutation PPP1R2E (R2E). The right schematic indicates position of PPP1R2 truncations which included PPP1R2 plasmids truncated at either the N-terminus PPP1R2?N (R2?N), deleting the PP1 binding site, or the C-terminus PPP1R2?C (R2?C), removing the AURKA binding site. These mutants were tested for their affect on centrosome number (c-f). Cells were transfected with the indicated proteins, fixed, and stained with anti-?-tubulin (green) and anti-a-tubulin (red). Size bar equals 10 µm. Insets show the region containing centrosomes. g Quantitation of the percentage of cells with supernumerary centrosomes after transfection with the indicated constructs. Statistically significant differences among groups are indicated by differing letter notations above the bars at p = 0.05 (*p = 0.01, **p = 0.001)