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目的应用偏最小二乘法,并结合Fisher精确检验实现原发性肝癌细胞遗传学异常区域的识别。方法利用Chen等发布在SMD上的原发性肝癌基因表达数据库,运用偏最小二乘法中的变量投影重要性(Variable mportance inthe Project,VIP)指标筛选肝癌异常表达基因,根据基因在染色体上的定位,计算每条染色体上的上调、下调基因以及正常表达基因,运用Fisher精确检验识别有统计学意义的细胞遗传学异常区域。结果得到基因表达增强区域7个(1q,5q,6p,8q,12q,17q,20q),表达下调区域为8个(4q,8p,9p,12p,13q,16q,17p,21q),15个异常区域已全部由实验方法证实。结论与传统的实验方法和一些预测算法相比,偏最小二乘法结合Fisher精确检验能够有效、快速地识别染色体基因异常表达区域,灵敏度有了较大提高。
Objective To apply Partial Least Squares method and Fisher’s exact test to identify the abnormal gene regions in primary hepatocellular carcinoma. Methods The primary hepatocellular carcinoma gene expression database published on Chen et al. Was used to screen the abnormal expression of hepatocellular carcinoma (HCC) gene by using the variable mportance inthe project (VIP) in partial least squares. According to the location of the gene on the chromosome , Calculating the up-regulation, down-regulation genes and normal expression genes on each chromosome, and using Fisher’s exact test to identify statistically significant cytogenetic abnormalities. Results Seven regions (1q, 5q, 6p, 8q, 12q, 17q and 20q) were found in the region of enhanced gene expression. The expression of downregulation region was 8 (4q, 8p, 9p, 12p, 13q, 16q, 17p and 21q) Abnormal areas have all been confirmed by experimental methods. Conclusion Compared with traditional experimental methods and some prediction algorithms, PLS combined with Fisher’s exact test can effectively and quickly identify abnormal expression regions of chromosomal genes, and the sensitivity has been greatly improved.