A. Parental cell line HCT116, as well as HCT116+Chr3 and HCT116+Chr3+DN2R cells were transfected with the 3TP-lux and pRL-TK reporter constructs, and treated with TGF-β1 (10ng/ml). TGF-_ mediated induction of the 3TP-Lux reporter is only apparent in the HCT116+Chr3 cell line. B. The effect of TGF-_ on DNA synthesis was evaluated in HCT116, HCT116+Chr3 and HCT116+Chr3+DN2R treated with TGF-β1 (10ng/ml) for 48h. All experiments were performed in triplicate. The bars correspond to S.E. TGF-_ suppression of thymidine incorporation is present only in the HCT116+Chr3 cell line. C. The effect of TGF-β on cell proliferation was assessed in HCT116, HCT116+Chr3 and HCT116+Chr3+DN2R treated as in 2B by measuring cell counts using a hematocytometer. All experiments were performed in triplicate. The bars correspond to S.E. TGF-β considerably reduces the proliferation of HCT116+Chr3 cells. Autocrine TGF-β signaling considerably reduces the proliferation of HCT116+Chr3 cells. The asterisks indicate statistically significant differences, p-value ≤ 0.05 as determined by the Student’s t-test.