CALR = calreticulin, siNC = nonspecific siRNA, siAPP = APP siRNA, and Cas = caspase 3. The single and double asterisks indicate p<0.05 and 0.01, respectively. (A) Co-immunoprecipitation of amyloid precursor protein (APP) with PCOLCE and CALR. (B–D) Inhibition in the transwell invasion (48 hr) (n=5) and scratch-based migration (24 hr) (n=4) of TT2 osteosarcoma (OS) cells by silencing the APP. (E) Suppression of PCOLCE (n=4) and CALR (n=5)-driven decrease in MTT-based viability of TT2 OS cells by partial deletion of APP. (F) Suppression of PCOLCE-induced changes of p-Src and cleaved caspase 3 (c-Cas) in TT2 cells by silencing APP. (G) Schematic diagram for the regulatory mechanism of tumor-suppressing action of CW008-treated MSC CM. (Scale bar, 200 µm, error bars indicate standard deviation.)