1. Figure1 HER2 SKBr3 PC3 A

2. SKBr3 cells Figure1 0 0.03 0.3 3 30 (µM) 120 100 80 60 40 20 0 Penetratin control % of control 0 0.03 0.3 3 30 (µM) 120 100 80 60 40 20 0 Peptidimer- c % of control 120 100 80 60 40 20 0 0 0.03 0.3 3 30 (µM) % of control 120 100 80 60 40 20 0 0 0.03 0.3 3 30 (µM) % of control PC3 cells Irrelevant peptide 0 1 3 10 30(µM) 120 100 80 60 40 20 0 B C D E F

3. A C Figure 2 % of colonies/control value D Untreated cells Peptidimer-c 0.03µM Docetaxel 0.03nM Peptidimer-c 0.03µM + Docetaxel 0.03nM Docetaxel 0.03nM + vector 0.03µM B Untreated cells Peptidimer-c 0.03µM Docetaxel 0.03nM Peptidimer-c 0.03µM + Docetaxel 0.03nM Docetaxel 0.03nM + vector 0.03µM SKBr3 cells PC3 cells SKBr3 cells

4. C P D P+D V+D V p44 p42 Figure 3 C: control P: peptidimer-c D: docetaxel V: Vector Total AKT Total ERK ½ p44 p42 Total Shc Actin Phospho-AKT Phospho-ERK 1/2 Phospho-Shc Seed cells peptidimer-c 30µM Days docetaxel 10nM Lysis Docetaxel 24h Peptidimer-c 48h D1D2D3D4D5 200 100 0 A B C D E 0 80 40 60 20 100 0 80 40 60 20

5. C P D P+ D PARP 116 kDa Cleaved PARP 85 kDa Figure 4 C: control P: peptidimer-c D: docetaxel Actin Seed of cells peptidimer-c 30µM Days docetaxel 10nM Lysis Docetaxel 48h Peptidimer-c 72h D1D2D3D4D5D6

6. Figure 5A * * * * p<0.05 Days after beginning of treatment Relative tumor volume 0 1 2 3 4 5 6

7. Figure 5B 1 2 3 4 pERK1/2 Actin Peptidimer-c Penetratin 120 100 80 60 40 20 0 % pERK1/2 / Actin D 0 D 2

8. Relative tumor volume Days after beginning of treatment Peptidimer-c 1.5 mg/kg i.p. control Figure 5C

9. Relative tumor volume control Peptidimer-c 1.5 mg/kg i.p. Docetaxel 20mg/kg i.p. Peptidimer-c 1.5mg/kg + docetaxel 20mg/kg Days after beginning of treatment * * * * p<0.05 Docetaxel 15mg/kg i.p. Peptidimer-c 1.5mg/kg + docetaxel 15 mg/kg * * * Figure 6 0 1 2 3 4 5 6