Growth of control and NAT1 knock-down cells <i>in vivo</i>.

<p>(<b>A</b>) Female Balb/c nude mice were injected subcutaneously with parental HT-29 cells (◊), Control 4 cells (•), or shRNA3.2 cells (○). Tumor volume was determined as outlined in the Methods. Results are mean ± SEM (<i>n</i> = 7–8). (<b>B</b>) Representative H&E staining of tumors (upper panels) from Control 4 (left panel) or shRNA 3.2 (right panel) showing large areas of necrosis (*) along with loosely organized columnar cells (small arrows). In the tumors derived from the shRNA 3.2 cells, more organized glandular structures were evident (large arrow). Representative immunohistochemistry for Ki67 in Control 4 and shRNA 3.2 tumors is shown in the middle and lower panels. (<b>C</b>) NAT1 activity in individual tumors from Control 4 and shRNA3.2 tumor tissue. The results are mean ± SEM (<i>n</i> = 3). (<b>D</b>) Real-time PCR of human NAT1 mRNA in individual tumors from Control 4 and shRNA3.2 tumor tissues. Results were normalized to β-actin and then expressed relative to Control 4. The results are mean ± SEM (<i>n</i> = 3).