ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of human alpha-mannosidase Man2c1 transgene on tumor growth and metastasis in mice.</p><p><b>METHODS</b>Hepatoma cell H22 or squamous epithelial carcinoma cell S180 was subcutaneously inoculated into the right armpit of mice (wild type mice and 28#, 35#, and 54# transgenic mice). Tumor size was measured every week. Mice were sacrificed on day 9 or 10 and then the tumors were exercised and weighted. Tumors and lungs were fixed in formaldehyde and sectioned. The sections were stained with hematoxylin/eosin and examined under microscope. The red blood cells in spleen were destroyed by Tris-NH4Cl. Natural killer (NK) cell activity was detected with Yac-1 cell as target.</p><p><b>RESULTS</b>H22 and S180 tumors grew faster in all the three transgenic mice (28#, 35#, and 54#) than in wild type mice. The average size and weight of tumors between the transgenic mice and wild type mice were significantly different (P<0.05). Most tumors in the transgenic mice invaded the surrounding tissues. In contrast, nearly all the tumors in wild type mice were capsulized. Three of 10 28# transgenic mice, 5 of 10 35# transgenic mice, 3 of 10 54# transgenic mice, and 1 of 10 wild type mice showed lung metastasis of H22 tumor. Two of 6 28# transgenic mice, 3 of 6 35# transgenic mice, 1 of 6 54# transgenic mice, and 0 of 6 wild type mice showed lung metastasis of S180 tumor. No difference of NK activity in spleen cells was observed between the transgenic mice and wild type mice.</p><p><b>CONCLUSIONS</b>hMan2c1 transgene promotes growth, invasion, and metastasis of transplanted H22 and S180 tumors in mice. hMan2cl transgene does not affect NK activity in splenocytes.</p>