Figure 4: POH1 inhibition suppresses tumour cell growth in vitro and in vivo.

(a) Human liver tumour cells with or without transfection of control siRNA or POH1 siRNA were examined by colony-formation assay. The representative results of three independent experiments are presented. (b) Mouse LPC-Mig, LPC-Akt and LPC-c-Myc cells transfected with control siRNA or POH1 siRNA were cultured for the colony-formation assays. The representative results of three independent experiments are presented. (c) PLC/PRF/5 cells with or without stable expression of POH1-Flag were cultured in attached or detached conditions for 72 h. Cells were subjected to apoptosis analysis. Data shown are mean±s.d. (by t-test, P value is shown in the graph, n=3). (d) SK-Hep1 cells with an inducible Tet-On-sh-POH1 expression cassette (sh-POH1) and control cells (empty vector) were subcutaneously injected into the right flanks of male BALB/c nude mice. The mice of each group were then randomly divided into two sub-groups and provided with normal drinking water (n=6) or with water containing 2 mg ml⁻¹ doxycycline (Tet-On) (n=6). The graph indicates tumour growth in the mice at the end of the experiment. Tumour volumes were measured at the indicated time intervals. Data shown are mean±s.e.m. P values calculated by ANOVA test are shown in the graph. (e) The tumour weights were quantified. Data shown are mean ±s.e.m. P values calculated by t-test are shown in the graph. (f) A photograph of the tumours in each group is presented. (g,h) Tumour formation in male BALB/c nude mice (n=5 or 6) injected subcutaneously with PLC/PRF/5 cell lines as indicated, the photograph of the tumours in each group is shown in (g); the tumour weight was quantified in (h). Data shown are mean ±s.e.m. P values calculated by t-test are shown in the graphs.