Fig. 4.

Expression of PCTAIRE1 promotes resistance against paclitaxel-induced cell death. (A) Western blot showing confirmation of PCTAIRE1 overexpression cell lines in MDA-MB-468 background. (B) Crystal Violet staining of the PCTAIRE1-overexpressing MDA-MB-468 cell line in the presence of paclitaxel (43 ng/ml) and nocodazole (100 ng/ml), showing increased cell survival compared to the control MDA-MB-468 cells. Cells were harvested after 2 weeks of drug treatments. (C) Graphical representation of the Crystal Violet staining results shown in B. (D) Western blot showing confirmation of PCTAIRE1 overexpression cell lines in U2OS background. (E) Crystal Violet staining of PCTAIRE1-overexpressing U2OS cell lines in the presence of paclitaxel (26 ng/ml), showing a number of surviving colonies of cells compared to the controls. Cells were stained after 2 weeks of drug treatment. (F) Graphical representation of the Crystal Violet staining results shown in E. (G) Crystal Violet staining of PCTAIRE1-overexpressing U2OS cell lines in the presence of nocodazole (50 ng/ml), showing larger and increased number of foci compared to the controls. Cells were harvested after 2 weeks of drug treatment. (H) Graphical representation of the Crystal Violet staining results shown in G. (I) Western blot showing CRISPR/Cas9-mediated knockdown of PCTAIRE1 in MDA-MB-468 cells stably expressing inducible Cas9 (iCas9) by using the sgRNA sequence of PCTAIRE1 indicated as sgPCT4. pLKO.1-sgGFP was used as a control. (J) Crystal Violet staining of PCTAIRE1 knockdown MDA-MB-468 cell lines (pLKO.1-sgPCT4) in the presence of paclitaxel (9 ng/ml) and nocodazole (10 ng/ml), showing decreased cell survival compared to the controls. Cells were harvested after 4 days of drug treatment. (K) Graphical analysis of the Crystal Violet staining results shown in J. Experiments for this figure were repeated 2−3 times. Data are presented as mean±s.d.; *P<0.05, **P<0.01 (two-tailed unpaired Student's t-test).