Objective   To investigate the effects of cell adhesion on interferon (IFN) and 5-fluorouracil (FU) induced cell apoptosis.    Methods   HepG

2

and HEK293 cells were classified into the 5 groups. Cells in group A were seeded into blank plates and not treated. Cells in group B were seeded into polylysine precoated plates followed by 5-Fu (250 μg/ml 4.2 μl) or IFN (500 U/ml 1.7 μl) treatment in 6 h after seeding. Cells in group C were seeded into blank plates and treated with 5-Fu or IFN in 6 h after seeding. Cells in group D were seeded into blank plates and treated with 5-Fu or IFN immediately after seeding. Cells in group E were seeded into blank plates and treated with anti-fibronectin antibody (500 μg/ml

1 μl) immediately after seeding

and then treated with 5-Fu or IFN in 6 h after seeding. Cell proliferation was detected by MTT assay

and cell apoptosis was detected by DNA fragmentation ELISA assay. Western blotting was used to detected PKR content in IFN-induced groups.    Results   Polylysine precoating plates decreased the drug sensitivity of cells. MTT assay showed that IFN on HepG

2

cells

the proliferation of B and C groups was inhibited by (27.24±31.77)% and (39.04±14.88)% respectively (P0.05); 5-Fu on HepG

2

cells

the proliferation of B and C groups was inhibited by (30.61±11.26)% and (32.94±20.93)% respectively (P0.05); IFN on 293 cells

the proliferation of B and C groups was inhibited by (32.02±23.48)% and (46.22±25.20)% respectively (P0.05); 5-Fu on 293 cells

the proliferation of B and C groups was inhibited by (14.07±21.

91)% and (31.61±31.49)% respectively (P0.05). DNA fragmentation ELISA indicated IFN on HepG

2

cells

the apoptosis of B and C groups was (0.425±0.038) and (0.535±0.039) respectively (P0.05); 5-Fu on HepG

2

cells

the apoptosis of B and C groups was (0.337±0.016) and (0.417±0.075) respectively (P0.05); IFN on 293 cells

the apoptosis of B and C groups was (0.394±0.033) and (0.499±0.018) respectively (P0.05); 5-Fu on 293 cells

the apoptosis of B and C groups was (0.406±0.024) and (0.504±0.069) respectively (P0.05). However

blocking the antifibronectin antibody (Fn) enhanced the drug sensitivity to cells. MTT assay showed that IFN on HepG

2

cells

the proliferation of D and E groups was inhibited by (49.90±11.90)% and (66.86±24.66)% respectively (P0.05); 5-Fu on HepG

2

cells

the proliferation of D and E groups was inhibited by (45.96±21.27)% and (68.76±31.41)% respectively (P0.05); IFN on 293 cells

the proliferation of D and E groups was inhibited by (58.98±32.96)% and (76.72±21.69)% respectively (P0.05); 5-Fu on 293 cells

the proliferation of D and E groups was inhibited by (47.02±26.84)% and (62.60±29.79)% respectively (P0.05). DNA fragmentation ELISA indicated IFN on HepG

2

cells

the apoptosis of D and E groups was (0.699±0.023) and (0.801±0.040) respectively (P0.05); 5-Fu on HepG

2

cells

the proliferation of D and E groups was (0.581±0.023) and (0.721±0.027) respectively (P0.05); IFN on 293 cells

the proliferation of D and E groups was (0.555±0.011) and (0.686±0.040) respectively (P0.05); 5-Fu on 293 cells

the proliferation of D and E groups was (0.590±0.062) and (0.704±0.011) respectively (P0.05). Western blot analysis showed PKR was decreased in blank group compared with the other groups respectively (P0.05)

however

there was no significant difference among B

C

D and E groups (P0.05).    Conclusion   Repression of cell adhesion enhances the sensitivity of cells to IFN and 5-Fu treatment. IFN enhances the phosphorylation of PKR

but has n

o relationship with cell adhesion.