Figure 5.

Effect of hPSC secretions and treatments on cancer cell functions in vitro: (n=5 separate hPSC preparations). For proliferation and migration studies, 0.1% SFM4MAb was used as the medium control and the results are expressed as the percentage of control. (A) Cancer cell proliferation: (i) AsPC-1 cells were incubated with medium control or medium treated with increasing concentrations (500–5000 pg ml⁻¹) of recombinant human HGF±AMG102. Compared with controls, rhHGF at 2000 pg ml⁻¹ induced maximal AsPC-1 proliferation (*P<0.005 vs medium control), and this effect was inhibited by AMG102. This experiment was performed as a ‘proof of concept' and to establish optimal concentrations of HGF to induce AsPC-1 cell functions (proliferation). (ii) AsPC-1 cells were incubated with medium control or untreated hPSC secretions or hPSC secretions pretreated either with AMG102 or gemcitabine or a combination of both. Compared with controls, hPSC secretions (Secr+IgG group) significantly induced AsPC-1 proliferation (**P<0.0001 vs control). This hPSC-induced AsPC-1 proliferation was significantly inhibited with AMG102 and gemcitabine as single agents (*P<0.05 vs Secr+IgG). However, the combination of both (Secr+Combn) did not have an inhibitory effect on AsPC-1 proliferation. (B) Cancer cell migration: hPSC secretions significantly induced AsPC-1 migration (Secr+IgG) when compared with medium control (*P<0.05 vs medium control). This hPSC-induced migration persisted in the presence of gemcitabine treatment (**P<0.01, *P<0.05 vs medium control) but was prevented with AMG102-treated secretions. (C) Cancer cell apoptosis: For apoptosis studies, AsPC-1 cells were serum starved in IMDM (Iscove's Modified Dulbecco's Medium) medium (medium control) to induce apoptosis or incubated with untreated hPSC secretions or hPSC secretions pretreated with AMG102, gemcitabine or AMG102+gemcitabine. Results were expressed as the percentage of control (medium control). hPSC secretions significantly inhibited AsPC-1 apoptosis (Secr+IgG) when compared with medium control (*P<0.01 vs medium control). The hPSC-induced antiapoptotic effect on AsPC-1 persisted in the presence of gemcitabine (Secr+Gem; *P<0.01 vs medium control) but not with AMG102 either as single agent (Secr+AMG102) or in combination with gemcitabine (Secr+Combn).