Rousseau A, Lim M S, Lin Z, Jordan R C
Faculty of Dentistry, University of Toronto, Toronto, Canada.
Oral Oncol. 2001 Apr;37(3):268-75. doi: 10.1016/s1368-8375(00)00114-7.
Amplification of the cyclin D1 gene has been identified in 17-55% of head and neck squamous cell carcinoma. In some tumors, this alteration has been associated with decreased survival and increased recurrence rates. In precancerous lesions of the mouth, the frequency of cyclin D1 gene amplification is not known. In addition, it is unknown whether amplification of the gene translates to overexpressed cyclin D1 protein in these lesions. We examined 59 formalin-fixed, paraffin embedded tissue biopsies of oral epithelial dysplasias (OED) and 25 oral squamous cell carcinoma (SCC) from the floor of the mouth for cyclin D1 gene and protein levels. Genomic DNA was extracted from laser microdissected lesional tissue and a duplex, quantitative PCR assay was used to determine the amplification of the cyclin D1 gene relative to interferon-gamma. Cyclin D1 protein expression was determined using immunohistochemistry and counting positive nuclei by computer image analysis. We found cyclin D1 gene amplification in 41% of mild, 45% of moderate and 24% of severe OEDs. Cyclin D1 was amplified in 36% of SCC. Overexpression of cyclin D1 protein was identified in 29% of mild, 47% of moderate, 29% of severe OED's, and in 32% of SCC. Overexpression of cyclin D1 protein was identified in similar proportions of all grades of dysplasia and SCC. There were statistically significant correlations identified between gene and protein levels in all categories of disease. We concluded that amplification of the cyclin D1 gene is frequent in OED and that duplex, quantitative polymerase chain reaction is a reliable method to detect this change in routinely processed biopsies. The strong correlation between cyclin D1 gene amplification and protein levels suggests that this method may be suitable to assess cyclin D1 gene status in tissues not suitable for protein analysis.
在17% - 55%的头颈部鳞状细胞癌中已发现细胞周期蛋白D1基因扩增。在一些肿瘤中，这种改变与生存率降低和复发率增加有关。在口腔癌前病变中，细胞周期蛋白D1基因扩增的频率尚不清楚。此外，在这些病变中该基因的扩增是否转化为细胞周期蛋白D1蛋白的过表达也不清楚。我们检测了59例口腔上皮发育异常（OED）的福尔马林固定、石蜡包埋组织活检标本以及25例来自口底的口腔鳞状细胞癌（SCC），以检测细胞周期蛋白D1基因和蛋白水平。从激光显微切割的病变组织中提取基因组DNA，并使用双链定量PCR测定法来确定细胞周期蛋白D1基因相对于干扰素-γ的扩增情况。使用免疫组织化学并通过计算机图像分析对阳性细胞核进行计数来确定细胞周期蛋白D1蛋白的表达。我们发现，在41%的轻度、45%的中度和24%的重度OED中存在细胞周期蛋白D1基因扩增。在36%的SCC中细胞周期蛋白D1被扩增。在29%的轻度、47%的中度、29%的重度OED以及32%的SCC中发现了细胞周期蛋白D1蛋白的过表达。在所有等级的发育异常和SCC中，细胞周期蛋白D1蛋白过表达的比例相似。在所有疾病类别中，基因和蛋白水平之间均存在统计学上的显著相关性。我们得出结论，细胞周期蛋白D1基因扩增在OED中很常见，并且双链定量聚合酶链反应是检测常规处理活检标本中这种变化的可靠方法。细胞周期蛋白D1基因扩增与蛋白水平之间的强相关性表明，该方法可能适用于评估不适合进行蛋白质分析的组织中的细胞周期蛋白D1基因状态。
