Figure 4

Loss of ICMT function obliterates the ability of established cancer cell lines carrying oncogenic mutant RAS to form tumors in vivo. (a) Schematic illustration of the predicted polypeptide sequences for each of the three alleles present in MiaPaca-2 cells expressing wild-type ICMT, as well as the truncated polypeptides predicted from each of the three mutant alleles in individual ICMT-null MiaPaCa-2 clones. The sequences of the mutated alleles are shown in Supplementary Table S2. The color scheme is the same as that in Figure 2b. (b) Growth of ICMT-wild-type MiaPaCa-2 xenografts. Tumor sizes were measured at 3–7 day intervals after implantation as shown; each trace denotes 1 tumor (n=3). (c) Measured sizes of ICMT-null MiaPaCa-2 implants from ICMT-null 1cr (n=3), ICMT-null 3cr (n=3), ICMT-null 4cr (n=3) cell lines. 3 × 106 cells were implanted for each MiaPaCa-2 xenograft, both ICMT wild-type and ICMT-null. (d) The mean final tumor size at the last measured time point for both ICMT wild-type and ICMT-null MiaPaCa-2 xenografts is shown. Two-tailed unpaired Welch’s t-test for unequal variances was performed; P=0.005 (**). (e) Photograph of a representative mouse showing the tumors at the time of killing. Red arrow: MiaPaCa-2-ICMT-wild-type tumor; blue arrow: remnant of the MiaPaCa-2-ICMT-null 4cr injection. (f) A similar schematic to (a) denoting the predicted polypeptide translated from each of the three alleles present in MDA-MB-231 expressing wild-type ICMT, as well as the truncated polypeptides translated from each of the three mutant alleles in individual MDA-MB-231 ICMT-null clones. The sequences of the mutated alleles are shown in Supplementary Table S2. Color scheme is the same as that in Figures 2b. (g) Growth of ICMT-wild-type MDA-MB-231 xenografts. Tumor sizes were measured every 3-7 days as indicated; each trace denotes 1 tumor (n=4). (h) Measured sizes of ICMT-null MDA-MB-231 xenografts resulting from the ICMT-null 1cr (n=4), ICMT-null 3cr (n=4), ICMT-null 4cr (n=4) lines. 1 × 107 cells were implanted for each MDA-MB-231 xenograft, both ICMT-wild-type or ICMT-null. (i) The mean final tumor size at the last measured time point for both ICMT-wild-type and ICMT-null MDA-MB-231 xenografts is shown. Two-tailed unpaired Welch’s t-test for unequal variances was performed; P<0.0001 (****). (j) Photograph of a representative mouse showing the tumors at the time of killing. Red arrow: MDA-MB-231-ICMT-wild-type tumor; blue arrow: MDA-MB-231-ICMT-null 4cr tumor.