Thiberville L, Bourguignon J, Metayer J, Bost F, Diarra-Mehrpour M, Bignon J, Lam S, Martin J P, Nouvet G
INSERM U.295, Faculté de Médecine Pharmacie de Rouen, France.
Int J Cancer. 1995 Dec 20;64(6):371-7. doi: 10.1002/ijc.2910640604.
Previous loss of heterozygosity (LOH) studies of chromosome 3p loci have displayed a 60% deletion frequency in non-small-cell lung cancers (NSCLC), as opposed to small-cell lung cancers, in which the 3p deletion is consistently found. However, the high stromal-cell admixture found in NSCLC and the use of the Southern-blot method lead to under-evaluation of this frequency. In this study, we used a very precise microdissection technique followed by PCR amplification of 6 3p21-22 polymorphic genomic sequences to analyze LOH in 86 NSCLC and in normal adjacent tissue. We found the sensitivity of the microdissection-PCR-based LOH technique higher than the sensitivity of the Southern-blot technique: 87% of the squamous-cell carcinomas and 84% of the large-cell undifferentiated carcinomas showed a clear LOH for a 3p21-22 locus. All doubly informative cases but 4 showed concordant deletion at all 3p21-22 loci. The analysis of 3p microsatellite sequences displayed only 2 cases of genomic instability, one of them also displaying features of tumoral heterogeneity as regards the instability genotype. Four carcinomas in situ adjacent to these NSCLC showed the same allelic profile as the invasive tumors. The only prognostic factors in this study were the disease stage and histology. The 3p21-22 deletion was not related to the stage of the disease and did not appear to be a significant prognostic factor of survival. 3p21 loss appears, so far, to be the most frequent and the earliest genetic alteration described in NSCLC, but does not seem to carry significant prognostic information in invasive tumors.
先前针对3号染色体短臂（3p）位点的杂合性缺失（LOH）研究显示，非小细胞肺癌（NSCLC）中该区域的缺失频率为60%，与之形成对比的是小细胞肺癌，后者始终存在3p缺失。然而，NSCLC中存在的高基质细胞混合比例以及Southern杂交方法的使用导致该频率被低估。在本研究中，我们采用了一种非常精确的显微切割技术，随后对6个3p21 - 22多态性基因组序列进行PCR扩增，以分析86例NSCLC及其癌旁正常组织中的LOH情况。我们发现基于显微切割 - PCR的LOH技术的灵敏度高于Southern杂交技术：87%的鳞状细胞癌和84%的大细胞未分化癌在3p21 - 22位点显示出明显的LOH。除4例之外，所有具有双信息性（doubly informative）的病例在所有3p21 - 22位点均显示出一致的缺失。对3p微卫星序列的分析仅显示2例基因组不稳定情况，其中1例在不稳定基因型方面还表现出肿瘤异质性特征。与这些NSCLC相邻的4例原位癌显示出与浸润性肿瘤相同的等位基因谱。本研究中唯一的预后因素是疾病分期和组织学类型。3p21 - 22缺失与疾病分期无关，似乎也不是生存的显著预后因素。到目前为止，3p21缺失似乎是NSCLC中描述的最常见且最早的基因改变，但在浸润性肿瘤中似乎并不携带显著的预后信息。
