口腔鳞癌中抑癌基因的失活

The Devitalization of Tumor Suppressor Genes in Oral Squamous Cell Carcinoma

目的 :探讨同一口腔鳞癌标本中 3种抑癌基因失活情况。方法 :2 7例口腔鳞癌标本行ABC免疫组织化学染色 ,一抗分别为鼠抗人nm2 3 ,P5 3单克隆抗体及P16多克隆抗体。以癌细胞着色 30 %为判断高低表达的界值。结果 :p16基因失活率最高 ,为 6 6 7% ;2种以上基因同时失活为 5 1 9% ,其中p16和nm2 3占 6 4 2 % (9 14)。结论 :p16基因失活是口腔鳞癌中发生频率最高的分子事件 ;口腔鳞癌中抑癌基因的失活为非单一基因失活 ,其意义值得探讨 ;同时提示 ,研究口腔鳞癌其基因表达及意义时 ,应注意抑癌基因失活的复杂性。

Objective:To study the expression of anti oncogenes nm23,P16, P53 of squamous cell carcinoma within one sample.Methods: A total of 27 cases of oral squamous cell carcinoma came from our the First Clinical College, China Medical University from 1997 to 1998, and none of them had the history of radioactivity therapy or chemical therapy. In them, 8 cases were in the early period, and 19 cases were in the late period. 15 cases were male and 12 cases were female. The samples were fixed in formaldehyde solution, embedded with paraffin, sliced in 5μm, and analysed by ABC immunohistochemistry staining. The first antibodies were anti P16, anti nm23, anti P53 respectively. The criteria of judgment were the following: For nm23,the case that cytoplasm or nuclea were buffy particles or ball was positive. For P16, the case that nuclea were brown was positive ,while the case with the light brown cytoplasm and unstained nuclea was negative. The stained nuclea of interstitial cells were treated as the control. For p53,the positive protein product was assembled in the carcinoma cell nuclea ,so the nucleus with buffy or brown particles was positive. According to the criteria, 5 high power sights were selected from each case, more than one hundred cells were counted. The case that the positive cells was more than 30 percentage was high expression, and less than 30 percentage was low expression. Two doctors completed the procedure respectively, and only the same results could be qualified.Results: In the 27 cases , the devitalization of nm23 and p16 was showed in low expression, p53 in high expression. The devitalization rate: p16 was 66 7% ,nm23 was 48 1%, and p53 was 25 9%. In 14 cases, combined mutation of two inhibitory genes were seen. 9 cases were p16 and nm23,among them, 4 cases had transferred to cervical lymph nodes ( In all the cases, there were 6 cases who had cervical lymph node transference).Conclusion: p16 genetic changes are more often detected in oral squamous cell carcinoma than the other genetic changes; In a large portion of cases, there were combined genetic changes instead of single gene mutation.\;