Figure 5.

The suppressive effect of MANS peptide on cancer metastasis in vivo. (a) The nude mice bearing subcutaneous tumors were treated with intratumoral injections of PBS (Con), RNS or MANS peptide at the dosage of 50 nmol every 2 days. Top, representative hematoxylin and eosin (H&E)-stained sections of the lungs from nude mice (n = 6) with subcutaneous tumors. The black arrow indicates the micrometastasis of subcutaneous PC9 cells to the lung. Bottom, total numbers of lung micrometastatic colonies in individual mice were counted under the dissection scope (*P < 0.05 vs Con). (b, c) Dissociated PC9 cells were orthotopically injected to the left lobe of the mouse lung as described in Materials and methods. After a week, mice were injected intraperitoneally with 500 µl of PBS or with PBS containing either the RNS or MANS peptide (50 nmol) once every 3 days thereafter for a total of six injections up to day 25. At day 25, mice were killed, and the organs were removed and examined. (b), Gross (left) and H&E-stained (right) pictures of various organs removed from mice. The arrows indicate tumor nodules in the organ. Bar = 20 µm. (c) Quantification of the average pulmonary metastasis nodules from mice with injected cancer cells and treated with RNS or MANS peptide as described (*P < 0.05 vs Con).