Fig 2: NTS contributes TTK-mediated cell proliferation. (A) NTS reversed cell proliferation inhibition (A), but not cell migration, as determined by wound healing (B) and the transwell system (C) by TTK knockdown. The cell proliferation of A549 or TTK knockdown A549 cells was determined by WST-1 after 72 h incubation. Control shRNA or TTK shRNA plasmid transfected A549 were seeded in the upper insert in serum-free medium with or without NTS. The complete culture medium was added into the lower well to act as a chemo-attractant for 24 h. The migratory cells were quantified by crystal violet staining. (D) NTS prevented the decrease of cyclin A and cdk2 regulated by TTK inhibition. NTS were added to A549 or TTK knockdown A549 cells for 24 h, the expression of various proteins was determined by an Immunoblot. (E) The relation of NTS with overall survival rate of lung cancer patients. The overall survival rate of lung cancer was obtained from the KM plotter website. All experiments were performed independently at least three times. * Significant difference between the two test groups (p < 0.05).

Fig 3: The gene profile of TTK-knockdown A549 cells. (A) The heat-map. The gene profile of TTK knockdown A549 cells was established by a microarray. (B) The decrease genes of TTK knockdown A549 cells. The expressions of various mRNAs were measured by qRT-PCR. Knockdown of TTK decreased neurotensin (NTS; C) and DYPSL3 (D) expression protein levels. The level of NTS in the supernatants of control or TTK knockdown A549 cells was determined by ELISA after 48 h incubation. The expression of DYPSL3 was assessed by an Immunoblot. All experiments were performed independently at least three times. * Significant difference when comparing with control group (p < 0.05).