Fig. 3: Mtb promotes tumor cell proliferation, migration and invasion partially depending on MKI67.

a Representative images of EdU proliferation assays of A549 cells. Cells were transfected with NC or MKI67 siRNA for 24 h, and infected with or without Mtb for 24 h. The proliferating cells were labeled with incorporated EdU-594 (red), and nuclei were stained with Hoechst 33342 (blue). Scale bars, 50 µm. b Quantification of EdU-positive cells as in a. Five independent visual fields were examined. c, e Transwell migration (c) and invasion (e) assays of A549 cells. Cells were transfected with NC or MKI67 siRNA for 24 h and infected with or without Mtb, and were then allowed to migrate or invade for 12 h. The white arrow indicates the cell (stained with DAPI, blue) that had moved through the filter, and the yellow arrow indicates the cell that was still moving through a pore. The arrowhead indicates Mtb (stained with Alexa Fluor 488 succinimidyl ester, green). Scale bars, 50 µm. d, f Quantification of cells that had migrated (d) or invaded (f) through the filter. Four independent visual fields were examined. g Quantitative PCR analysis of MKI67 mRNA in A549 cells. Cells were infected with the indicated Mtb strains or not for 48 h. h Representative images of Ki-67 and PtpA immunohistochemical analysis of A549 cells treated as in g. Scale bars, 50 μm. i Quantitative analysis of Ki-67 expression as in h. Four independent visual fields were examined. P > 0.05, not significant (ns); *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 (mean ± s.e.m. of n = 5 in b, and n = 4 in d, f, g, and i, one-way ANOVA). All experiments were repeated at least three times independently.