Hughson M D, Meloni A, Dougherty S, Silva F G, Sandberg A A
Section of Pathology and Laboratory Medicine, Department of Veterans Affairs Medical Center, Northport, New York 11768-2290, USA.
Cancer Genet Cytogenet. 1996 Apr;87(2):133-9. doi: 10.1016/0165-4608(95)00274-x.
Nonpapillary renal cell carcinomas (RCCs) are characterized by deletions of the short arm of chromosome 3 (3p) and papillary RCCs by increased numbers of selected chromosomes. Although recent molecular genetic studies have reported some papillary RCCs to show loss of heterozygosity (LOH) on 3p, a 3p deletion has not been demonstrated in a papillary RCC by karyotype analysis. To investigate this apparent discrepancy between molecular methods and chromosomal changes in the genetic evaluation of RCC, a series of 13 papillary and nonpapillary RCCs was investigated for 3p LOH by PCR-based restriction fragment length polymorphism (PCR-RFLP) analysis and for 3p and 3q LOH by microsatellite analysis. Karyotypes were obtained in six cases. Loss of 3p but not of 3q alleles was found in 8 of 10 nonpapillary RCCs. The region of overlapping deletion was 3p14--p21, and in six cases the deletion involved 3pter loci. One papillary RCC displayed 3p and 3q LOH, but the tumor had two morphologically normal chromosomes 3 and several trisomies. This indicated that nondisjunction of a chromosome from one parent compensated a whole chromosome loss from the other parent during tumor development. LOH in this papillary RCC constituted a reduction of chromosome 3 alleles to homozygosity, but the karyotype change, consisting of an increased number of whole chromosomes and an absence of a structural chromosome 3 abnormality, is regarded as being more characteristic of papillary than nonpapillary RCC.
非乳头状肾细胞癌（RCC）的特征是3号染色体短臂（3p）缺失，而乳头状RCC的特征是特定染色体数量增加。尽管最近的分子遗传学研究报告称一些乳头状RCC在3p上显示杂合性缺失（LOH），但通过核型分析尚未在乳头状RCC中证实3p缺失。为了研究RCC基因评估中分子方法与染色体变化之间的这种明显差异，通过基于聚合酶链反应（PCR）的限制性片段长度多态性（PCR-RFLP）分析对一系列13例乳头状和非乳头状RCC进行了3p LOH检测，并通过微卫星分析对3p和3q LOH进行了检测。6例获得了核型。在10例非乳头状RCC中的8例中发现了3p等位基因缺失，但未发现3q等位基因缺失。重叠缺失区域为3p14 - p21，6例中缺失涉及3pter位点。1例乳头状RCC显示3p和3q LOH，但该肿瘤有两条形态正常的3号染色体和几条三体染色体。这表明在肿瘤发生过程中，来自一方亲本的染色体不分离补偿了另一方亲本的整条染色体缺失。该乳头状RCC中的LOH导致3号染色体等位基因减少至纯合性，但核型变化包括整条染色体数量增加且不存在3号染色体结构异常，被认为比非乳头状RCC更具乳头状特征。
