Table 1.
IGF-1R expression by HRS cells in relation to disease parameters, EBV status and treatment.
Figure 1.
IGF-1R expression in HRS cells.
A, Representative cHL case showing expression of IGF-1R in the vast majority of HRS cells. B, pIGF-1R positive HRS cell. C, IGF-1R expression in L428, showing positive staining in all cells with strong expression in mitotic cells, D, IGF-1R expression in L1236, showing weak staining in all cells and strong expression in mitotic cells and, E, IGF-1R expression in KM-H2, showing weak staining with more pronounced expression in mitotic cells.
Figure 2.
Kaplan-Meier curves for progression free survival (PFS) and overall survival (OS) in IGF-1R expression defined subgroups of cHL patients.
The overall survival was lower in the IGF-1R negative group (83%) as compared to the IGF-1R positive group (98%; P = 0.029). The 5-year PFS was lower in the IGF-1R negative group (77%) as compared to the IGF-1R positive group (93%; P = 0.047). Numbers below the graph are the number of patients for each group included at that time point.
Figure 3.
IGF-1R and IGF-1 expression and the effect of IGF-1 on growth in cHL cell lines.
A, Western blot showing expression of IGF-1R in L428, KM-H2 and L1236. The IGF-1R level was high in L428, moderate in L1236 and low in KM-H2. B, IGF1 protein levels in the culture supernatant of cHL cell lines. The IGF-1 protein levels were similar in the three cHL cell lines. C, IGF-1 treatment of L428 cells revealed a significant effect on cell growth. D, L1236 cells showed a significant effect on cell growth upon IGF-1 treatment. E, no effect was seen in KM-H2 cells upon treatment with IGF-1.
Figure 4.
The effect of PPP on growth of cHL cell lines.
A, L428 cells. B, L1236 cells. C, KM-H2 cells. Cell growth upon treatment with 2 µM PPP (black bars) for 1, 2 and 3 days was compared with untreated/DMSO control treatment (white bars). Cell growth was significantly decreased (P<0.001) in all three cell lines.
Figure 5.
The effect of PPP on cell cycle progression of cHL cell lines.
A, L428 cell cycle analysis. B, L1236 cell cycle analysis. C, KM-H2 cell cycle analysis. Flow cytometry histograms are given with a fitted analysis model, in which dark gray areas are calculated areas for cells in G0/G1 and G2 phase and the shaded area is the calculated area for cells in S phase. Cell cycle distribution upon treatment with PPP (2 µM)-treated for 24 hours revealed a clear G2/M cell cycle arrest in all cell lines. Representative figures are given. Results of triplicate experiments are given in supplementary figure 2.
Figure 6.
The effects of IGF-1 and PPP on IGF-1R autophosphorylation and on its downstream signalling proteins and cell cycle proteins in L428 cells.
A, pIGF-1R level was measured at different time points after stimulation with IGF-1 (50 ng/mL). Phosphorylation levels of IGF-1R, Akt and ERK were increased upon IGF-1 stimulation at 20 and 30 minutes. B, phosphorylation of IGF-1R, and Akt upon IGF-1 stimulation could be blocked by the pIGF-1R kinase inhibitor PPP in L428 cells. While phosphorylation of ERK was increased by PPP (C) PPP treatment induced a reduction of Cdc2 phosphorylation and upregulation of CyclinB1, consistent with the occurrence of a G2/M-phase cell cycle arrest.