Spica Prunellae Extract Enhances Fluorouracil Sensitivity of 5-Fluorouracil-Resistant Human Colon Carcinoma HCT-8/5-FU Cells via TOP2α and miR-494

Figure 2

Overexpression of TOP2α mediates the 5-FU resistance. (a, b) Analysis of TOP2A expression levels in the GEPIA database and Mega-sampler in the TCGA database. (c) Detection of relative protein levels for HCT-8 and HCT-8/5-FU cells treated with or without 5-FU (3.2 mM) for 48 h by western blot and (d) quantification. (e) Real-time PCR evaluation of the mRNA levels of TOP2A. The data from western blot and real-time PCR are normalized to GADPH. Relative cell viability of HCT-8/5-FU cells transfected with (f) siRNA or (g) miR-494 and then treated with or without 5-FU (3.2 mM) for different time periods (1, 2, 3, and 4 days). (h) Cell colonies for HCT-8/5-FU cells transfected with siRNA or miR-494 and then treated with or without 5-FU (3.2 mM) for 48 h and (i, j) their relative numbers for cell colonies were analyzed. Compared with the negative control group, for siRNA or miR-494 transfection, , , and ; for negative control treatment with the 5-FU group (NC + 5-FU), , , and ; for siRNA or miR-494 transfection and treatment with the 5-FU group (NC + 5-FU), , , and .

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