de Boer C J, Kluin-Nelemans J C, Dreef E, Kester M G, Kluin P M, Schuuring E, van Krieken J H
Department of Pathology, University of Leiden, The Netherlands.
Ann Oncol. 1996 Mar;7(3):251-6. doi: 10.1093/oxfordjournals.annonc.a010568.
Previous results suggested increased mRNA expression of CCND1 in hairy cell leukemia (HCL). The CCND1 gene is involved in the t(11;14)(q13;q32) chromosomal rearrangement, a characteristic abnormality in mantle cell lymphoma (MCL). We and others reported that, in contrast to other B-cell lymphomas, almost all MCL have over-expression of the CCND1 gene with a good correlation between RNA and protein analysis. Recent studies showed that overexpression of the cyclin D1 protein can be easily detected by immunohistochemistry (IHC) on formalin-fixed, paraffin embedded tissues.
To investigate whether the CCND1 gene is involved in HCL, we performed IHC on a series of 22 cases using formalin-fixed paraffin embedded splenectomy specimens. For IHC the sections were boiled in citrate buffer. The presence of rearrangements within the BCL-1 locus and the CCND1 gene was analyzed in 13 of 22 cases by Southern blot analysis using all available break-point probes. Expression of CCND1 was analyzed at the mRNA level (Northern blot) and protein level (IHC).
Overexpression of the cyclin D1 protein using IHC was observed in all cases, with strong expression in 5 cases. Pre-existing B- and T-cell areas of the spleen did not express significant levels of the cyclin D1 protein. Seven of 9 cases analyzed by both IHC and Northern blotting showed overexpression of the CCND1 gene with both methods. No genomic abnormalities were observed in any of the 13 cases studied by Southern blot analysis. Additionally, no 11q13 abnormalities were detected by banding analysis of 19 of 22 cases.
The elevated levels of CCND1 mRNA and protein in conjunction with the absence of overt rearrangements within the BCL-1 locus distinguish HCL from MCL and other B-cell malignancies. This suggests that activation of the CCND1 gene in HCL is due to mechanisms other than chromosomal rearrangement.
先前的研究结果表明，毛细胞白血病（HCL）中CCND1的mRNA表达增加。CCND1基因参与t(11;14)(q13;q32)染色体重排，这是套细胞淋巴瘤（MCL）的特征性异常。我们和其他人报告称，与其他B细胞淋巴瘤不同，几乎所有MCL都有CCND1基因的过表达，RNA和蛋白质分析之间具有良好的相关性。最近的研究表明，通过免疫组织化学（IHC）在福尔马林固定、石蜡包埋的组织上可以很容易地检测到细胞周期蛋白D1蛋白的过表达。
为了研究CCND1基因是否参与HCL，我们使用福尔马林固定石蜡包埋的脾切除标本对一系列22例病例进行了IHC检测。对于IHC，切片在柠檬酸盐缓冲液中煮沸。使用所有可用的断点探针，通过Southern印迹分析对22例中的13例进行了BCL-1基因座和CCND1基因内重排的检测。在mRNA水平（Northern印迹）和蛋白质水平（IHC）分析CCND1的表达。
所有病例均观察到使用IHC检测的细胞周期蛋白D1蛋白过表达，5例为强表达。脾脏先前存在的B细胞和T细胞区域未表达显著水平的细胞周期蛋白D1蛋白。通过IHC和Northern印迹分析的9例病例中有7例两种方法均显示CCND1基因过表达。Southern印迹分析研究的13例病例中均未观察到基因组异常。此外，22例中的19例通过带型分析未检测到11q13异常。
CCND1 mRNA和蛋白质水平升高，以及BCL-1基因座内无明显重排，可将HCL与MCL和其他B细胞恶性肿瘤区分开来。这表明HCL中CCND1基因的激活是由染色体重排以外的机制引起的。
