Abstract
Purpose: :
To know the phenotype of ocular melanoma and its metastasis in the pigment epithelium-derived factor (PEDF) knockout mouse model.
Methods: :
B16LS9 cells were inoculated into the PEDF gene knockout homozygote and heterozygote mice, and gene background control C57BL6 mice. At the 7th day after inoculation, the eye was checked with histological methods, and the largest area of ocular tumor was measured under microscope with Image J. At the 28th day, the size of ocular tumor and the sizes and number of the hepatic micrometastasis were measured and counted.
Results: :
The average size of ocular melanoma in PEDF homozygote mice (674164 ± 105900 pixel2) was larger than one in PEDF heterozygote mice (546472 ± 86532 pixel2) and gene background control mice (410607 ± 70049 pixel2). There were significant statistical differences in the size of ocular tumor between two groups (P<0.01). The numbers of hepatic metastasis in the PEDF gene knockout homozygote and heterozygote mice, and gene background control C57BL6 mice were separately 153 ± 87, 108 ± 23, 108 ± 39. No significant difference was noted by a t-test between the two groups (P>0.1). Hepatic metastases which diameter was 3 mm were observed in the PEDF gene knockout homozygote mice. The micrometastases were merely surveyed in the gene background control mice. The average size of hepatic metastasis in the PEDF gene knockout heterozygote (3913 ± 5164 pixel2) was smaller than one in the PEDF gene knockout homozygote (82743 ± 319357 pixel2), but larger than one in the gene background control mouse (649 ± 719 pixel2). There were significant statistical differences in the sizes of metastases between the groups (P<0.01).
Conclusions: :
PEDF plays an important role in the growth and spreading of ocular melanoma. Loss of PEDF enhances the progression of ocular melanoma and its metastasis.
Keywords: melanoma • gene modifiers • transgenics/knock-outs