Fig. 4

Increased expression of YB-1 and ABCB-1 in sunitinib-resistant compared to sunitinib-sensitive phenotypes. a Western blot and RT-PCR results show significant increase in YB-1 and ABCB-1 protein and mRNA levels in Caki-1 DC compared to Caki-1WT. b Increased YB-1 and ABCB-1 was also observed by immunofluorescence staining evaluation. c Immunohistochemical staining of YB-1 and ABCB-1 in our acquired sunitinib-resistant mouse model (n = 3–4) and patient samples (n = 5–7). d Western blot and RT-PCR results of YB-1 knockdown in Caki-1WT and Caki-1 DC showing significant downregulation of YB-1 protein and mRNA levels. The protein expression of its downstream target, ABCB-1, also decreased but the mRNA level remained unchanged. Data are mean ± SEM. Immunohistochemical images at scale bar 100 μm. Results are representative of three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.0005, ****p < 0.0001