Figure 6From: Novel synergistic antitumor effects of rapamycin with bortezomib on hepatocellular carcinoma cells and orthotopic tumor model In vivo mechanism of antitumor activity of rapamycin and bortezomib in xenograft model. (A) Ex vivo immunohistochemistry staining of Akt, p-Akt, PCNA, CD31 or TUNEL in HCCLM3-R xenografts (magnification, ×200). The staining of p-Akt was increased in rapamycin-treated tumors, but inhibited in bortezomib- or the combination-treated tumors. (B) The increase of p-Akt in rapamycin-treated tumors and the decrease in bortezomib-treated tumors were also observed by Western blot analysis. Rapamycin-induced Akt phosphorylation was abrogated by bortezomib in the combination-treated tumors. (A, C) Quantitation of PCNA positive cells demonstrated that rapamycin or bortezomib significantly inhibited tumor growth, as compared with control (* P < 0.05), which was markedly enhanced by the combination of both agents (** P < 0.01, versus control group and †P < 0.01 versus monotherapy). (A, D) The average number of CD31-positive vessels was significantly reduced in tumors from the rapamycin monotherapy group (* P < 0.05, versus control group), which was further enhanced by the combined therapy of rapamycin and bortezomib (** P < 0.01, versus control group; and # P < 0.05, versus rapamycin group). (A, E) The number of TUNEL-positive cells in tumors was significantly elevated in bortezomib treatment group (** P < 0.01, versus control group) and the combined treatment group (** P < 0.01, versus control group or rapamycin group).Back to article page