Oncogene mutation analysis that uses malignant melanoma model mouse and mRNA analysis by ISH method.

我们分析了p16肿瘤抑制基因的突变和甲基化，使用UVB诱导xpa缺陷（-/-），干细胞因子转基因（SCF-Tg）小鼠黑色素瘤。方法：提取基因组DNA。通过PCR扩增外显子1和外显子2的全长，然后进行直接测序和甲基化特异性PCR。结果与讨论：10份NM样品中有5份（50%）p16基因完全缺失，其余NM样品未见点突变。在任何LMM， SCC或慢性uvb照射的皮肤样本中均未观察到突变。NM样品中10例中有3例（33%）检测到DNA甲基化，LMM样品中14例中有1例（7%）检测到DNA甲基化。这些结果提示p16基因的缺失和甲基化会导致我们模型小鼠NM型的癌变，而p16基因突变以外的其他因素可能参与了LMM型的癌变。

We analyzed the mutation and methylation of p16 tumor suppressor gene, using UVB induced melanoma in XPA-deficient (-/-), stem cell factor-transgenic (SCF-Tg) mice. Method : Genomic DNA was extracted. The full lengths of exon 1 and exon 2 were amplified by PCR, followed by the direct sequencing and methylation specific PCR. Results and discussion: The complete deletion of p16 gene was observed in 5 of 10 (50%) NM samples, and no point mutation was observed in other NM samples. No mutation was observed in any sample of LMM, SCC, or chronically UVB-irradiated skin. DNA methylation was detected in 3 of 10 (33%) in NM samples and 1 of 14 (7%) in LMM samples. These results suggest that the deletion and methylation of p16 gene would lead to the carcinogenesis of NM type in our model mouse, and the factor(s) other than p16 gene mutation would be involved in the carcinogensis of LMM type.