Frequent alterations of cell-cycle regulators in astrocytic tumors as detected by molecular genetic and immunohistochemical analyses.
Frequent alterations of cell-cycle regulators in astrocytic tumors as detected by molecular genetic and immunohistochemical analyses.
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DOI：
10.1007/bf02478888
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发表时间：
1998-01-01
影响因子：
3.3
通讯作者：
Sakaki, T
中科院分区：
文献类型：
--
作者：
Nakamura, M;Konishi, N;Sakaki, T
采用分子遗传学和免疫组织化学相结合的方法，研究CDKN2A、Rb和细胞周期蛋白D1基因及其产物在星形细胞肿瘤中的表达变化。此外，还评估了基因状态与临床结果的关系。应用聚合酶链式反应-单链构象多态分析、直接测序和Western blotting分析30例皮损中CDKN2A和Rb基因的改变。用甲基化特异性聚合酶链式反应检测CDKN2A启动子的甲基化。应用免疫组织化学方法检测94例患者肿瘤组织中基因产物的表达，并对患者的临床结果进行评估。CDKN2A基因分析发现12个纯合子或半合子缺失，1个外显子1突变，3个启动子甲基化。30例中18例未检测到p16蛋白表达。4例(13%)Rb基因突变导致pRb蛋白表达缺失，其中6例免疫组织化学检测为阴性。在94例乳腺癌中，有51例(54%)有细胞周期蛋白D1过表达。PRb阴性肿瘤患者的早期死亡风险显著高于p16和细胞周期蛋白D1改变的患者，p16和pRb免疫组织化学提供了有用的互补信息，并可能在筛查中提供有价值的预测信息。对细胞控制通路上的单个成分解除管制的生物学后果是不平等的，这可能反映了它们在G1检查点中的等级角色。
Alterations of CDKN2A, RB, and cyclin D1 genes and expression of their products in astrocytic tumors were studied using a combination of molecular genetic and immunohistochemical assays. In addition, the association of gene status with clinical outcome was evaluated. Alterations of CDKN2A and RB gene in 30 lesions were analyzed by single-strand conformation polymorphism of polymerase chain reaction (PCR-SSCP), direct sequencing, and Western blotting. Methylation of the CDKN2A promoter was detected by methylation-specific PCR. Immunohistochemistry was applied to determine the expression of gene products in tumors from 94 patients for whom clinical outcome was also evaluated. Analyses of the CDKN2A gene revealed 12 homozygous or hemizygous deletions, one mutation in exon 1, and three methylations in the promoter. Expression of p 16 protein was not detected in 18 of 30 cases. RB mutations leading to loss of expression of the pRb were found in four (13%) cases, and six were immunohistochemically negative for this protein. Overexpression of cyclin D1 was obtained in 51 (54%) of 94 cases. Patients with pRb-negative tumors had a significantly greater risk of earlier death than those with p16 and cyclin D1 alterations, Both p16 and pRb immunohistochemistry provides useful complementary information and may provide valuable predictive information in screening. The biological consequences of deregulating individual components along cell control pathways are unequal, perhaps reflecting their hierarchical roles in the G1 checkpoint.