Fig. 3.

Compound 6 blocks CTSS mediated MC38 cell invasion and HUVEC endothelial tube formation. a Compound 6 attenuates MC38 invasion Left: Treatment of MC38 cells with 1000 nM compound 6 significantly reduced tumor cell invasion as determined by measuring invaded cells per field of view (pfv) (**P<0.01). Right: representative images. To evaluate compound 6 selectivity in a cellular assay, murine colorectal cell line MC38 was transfected with either a non-targeting construct (NTC) or CTSS knock-down construct (sh835). b Diminished CTSS expression was confirmed by RT-PCR. c The invasiveness of the MC38 NTC and sh835 cells was analysed by transwell assay. MC38 sh835 cells demonstrated reduced invasive potential compared to the MC38 NTC cells (***P<0.001). Treatment of MC38 NTC cells with compound 6 (1000 nM) resulted in a significant reduction in invasion (***P<0.001). No further effect was observed with treatment of MC38 sh835 cells with compound 6 (1000 nM). d Left: Compound 6 significantly reduced HUVEC endothelial tube formation approximately 10 % from 100 nM (***P<0.001). Right: representative images