Baur A S, Shaw P, Burri N, Delacrétaz F, Bosman F T, Chaubert P
Institut Universitaire de Pathologie, Lausanne, Switzerland.
Blood. 1999 Sep 1;94(5):1773-81.
The methylation status of p15(INK4b) (MTS2), p16(INK4a) (MTS1) and p14(ARF) (p16beta) was analyzed in 56 lymphomas by restriction-enzyme related polymerase chain reaction (PCR) (REP), methylation-specific PCR (MSP), and bisulfite genomic sequencing (BGS). Methylation of the p15 and p16 genes was detected, respectively, in 64% and 32% of the B-cell lymphomas, in 44% and 22% of the T-cell lymphomas, and in none of the 5 reactive lymph nodes analyzed. Both p15 and p16 genes were methylated more often in the high-grade (78% and 50%, respectively) than in the low-grade B-cell lymphomas (55% and 21%, respectively). For 5 cases, mapping of the methylated CpGs of the p16 promoter region confirmed the results of REP and MSP. In addition, a large variation in the methylation patterns of p16 exon 1 was observed, not only from one lymphoma to another, but also within a given tumor. Methylation of p15 and p16 was associated with an absence of gene expression, as assessed by reverse transcription-PCR. The p14 gene was unmethylated and normally expressed in all 56 tumors. We found no mutations of p15, p16, or p14 in any of the 56 lymphomas. Our results suggest a role for p15 and p16 gene methylation during lymphomagenesis and a possible association between p15 and p16 inactivation and aggressive transformation in B-cell and T-cell lymphomas.
采用限制性内切酶相关聚合酶链反应（PCR，即REP）、甲基化特异性PCR（MSP）和亚硫酸氢盐基因组测序（BGS），对56例淋巴瘤中p15（INK4b，即MTS2）、p16（INK4a，即MTS1）和p14（ARF，即p16β）的甲基化状态进行了分析。在B细胞淋巴瘤中，分别有64%和32%检测到p15和p16基因甲基化；在T细胞淋巴瘤中，分别有44%和22%检测到甲基化；而在所分析的5个反应性淋巴结中均未检测到甲基化。在高级别B细胞淋巴瘤中，p15和p16基因甲基化的频率更高（分别为78%和50%），而在低级别B细胞淋巴瘤中甲基化频率分别为55%和21%。对于5例病例，p16启动子区域甲基化CpG的定位证实了REP和MSP的结果。此外，不仅在不同淋巴瘤之间，而且在同一肿瘤内部，均观察到p16外显子1甲基化模式存在很大差异。通过逆转录PCR评估，p15和p16甲基化与基因表达缺失相关。在所有56个肿瘤中，p14基因均未甲基化且正常表达。在56例淋巴瘤中，未发现p15、p16或p14有任何突变。我们的结果提示p15和p16基因甲基化在淋巴瘤发生过程中发挥作用，并且p15和p16失活与B细胞和T细胞淋巴瘤的侵袭性转化之间可能存在关联。
