Fig 1.
Quercetin combined with 2-ME enhanced inhibition of PC-3 xenograft tumor growth.
(A) PC-3 xenograft tumors were smaller in Que or 2-ME treatment group than vehicle control, and the inhibition was more remarkable in Que and 2-ME co-treatment group. Tumor weight (B) and tumor volume (C) were reduced significantly by combination therapy, more obvious than Que or 2-ME alone. There was no significant difference in mouse weight between groups (D). Data are represented as means ± SD. *P<0.05 compared with control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 2.
Quercetin combined with 2-ME enhanced inhibition of LNCaP xenograft tumor growth.
(A) LNCaP xenograft tumors were smaller in Que or 2-ME treatment group than vehicle control, and the inhibition was more notable in combination treatment group. Que and 2-ME combination therapy reduced tumor weight (B) and tumor volume (C) greatly, more effective than Que or 2-ME alone. No significant influence on mouse weight was observed between groups (D). Data are represented as means ± SD. *P<0.05 compared with control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 3.
Quercetin combined with 2-ME increased Bax/Bcl-2 ratio in PC-3 and LNCaP xenograft tumor tissues.
(A) Western blot detected Bax and Bcl-2 protein expression. (B, C) Bax/Bcl-2 ratio was represented as means ± SD (mean in triplicate). *P<0.05 compared to untreated control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 4.
Quercetin combined with 2-ME increased cleaved caspase-3/caspase-3 ratio in PC-3 and LNCaP xenograft tumor tissues.
(A) Western blot detected cleaved caspase-3 and caspase-3 protein expression. (B, C) Cleaved caspase-3/caspase-3 ratio was represented as means ± SD (mean in triplicate). *P<0.05 compared to untreated control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 5.
Quercetin combined with 2-ME inhibited proliferation and promoted apoptosis in PC-3 and LNCaP xenograft tumor tissues.
(A, D) Immunohistochemical detection showed Ki67 and caspase-3 positive cells in both PC-3 and LNCaP xenograft tumor. Number of Ki67 (B, C) and caspase-3(E, F) positive cells were represented as means ± SD, number was from three random high powered fields per slide (light microscopy, hpf, 400×). *P<0.05 compared to control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 6.
Quercetin combined with 2-ME decreased pAKT protein expression in PC-3 and LNCaP xenograft tumor tissues.
(A) pAKT and AKT protein expression were examined by western blot. Values of pAKT (B, C) and AKT (D, E) were represented as means ± SD (values from three independent experiments). *P<0.05 compared to untreated control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 7.
Quercetin combined with 2-ME decreased VEGF protein and mRNA in PC-3 and LNCaP xenograft tumor tissues.
VEGF protein (A) and mRNA (D, E) expression were examined by western blot and quantitative real time PCR. Values of VEGF protein (B, C) and mRNA (D, E) were represented as means ± SD (values from three independent experiments). *P<0.05 compared to untreated control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.
Fig 8.
Quercetin combined with 2-ME decreased microvessel density in PC-3 and LNCaP xenograft tumor tissues.
(A, D) Immunohistochemical examination exhibited CD31 and CD34 positive vessels in both PC-3 and LNCaP xenograft tumor tissue. Number of CD31 (B, C) and CD34 (E, F) positive vessels were represented as means ± SD, number was from three random high powered fields per slide (light microscopy, hpf, 400×). *P<0.05 compared to control, #P<0.05 denotes a significant difference between combination treatment group and quercetin treated group, ※P<0.05 denotes a significant difference between combination treatment group and 2-ME treated group.