Autocrine transforming growth factor-α is associated with modulation of a 130 kD RB protein species and 116/110 Rb as revealed by an antisense TGFα expression vector

Specific RB protein species modulated by autocrine TGFα are unknown. HCT116 cells transfected with TGFα antisense expression vector were compared with control HCT116 NEO for mitogenesis and modulation of high MW (130, 120 kD) and low MW (116, 110, 105 kD) RB species. Nutrients alone (N) induced maximal mitogenesis in HCT116 NEO and modulated both 130 kD and 116 kD/110 kD RB species. TGFα antisense transfected clones required nutrients plus growth factors (GF) for maximal mitogenesis and both 130 kD/120 kD as well as 116 kD/110 kD species were modulated. Thus, autocrine TGFα (HCT116) was associated with 130 kD and 116/110 kD modulation while its suppression allowed modulation of a 120 kD species as well.