Figure 6

Restoration of MAOA expression inhibits cholangiocyte proliferation. Proliferative capacity was assessed in a cell line overexpressing MAOA (Mz-MAOA+) compared with the control cell line (Mz-pCMV6) by immunoblotting for PCNA (a). Data are expressed as average±s.d. (n=4) after normalization for loading with β-Actin. (*P<0.05 compared with Mz-pCMV6 cells). Representative PCNA immunoblots are shown; β-Actin is shown as a loading control. Cell-cycle progression was assessed by flow cytometry and the percentage of cells in the G0/G1, S and G2 phases determined (b). In vivo, Mz-MAOA+ and Mz-pCMV6 cells were injected into the flank of athymic mice. After tumors were established (12 days), tumor volume was measured for a further 50 days (n=6; c). In our human samples, PCNA mRNA expression for each sample was then correlated with the MAOA mRNA expression levels from each sample (d) and was significantly correlated (P=0.024) with a correlation coefficient of r=−0.59696. The invasive capacity of Mz-pCMV6 and Mz-MAOA+ cells was assessed using a commercially available invasion assay. The invasion index was determined as the percentage of invading cells in the invasion chamber compared with the invading cells in the control chambers (e). Data are expressed as average±s.d. (*P<0.05).