目的:研究先天性肺畸形(CLMs)与恶性肿瘤的生物学关系。
方法:12个CPAM的活检,通过全基因组测序分析了6个叶内测序和2个叶外测序。来自10名患者的血液样本用于确认或排除躯体镶嵌。对于每个畸形样品调用推定的体细胞单核苷酸变体(SNV),并使用从血液中提取的对照DNA样品构建了一个常规小组。随后通过Sanger测序确认了这些变异,并进行了搜索,只要有可能,在病人的血液样本中.
结果:所有CLM,除了一个CLM,都通过具有基因突变的多个细胞簇表现出基因组不稳定性的特征。在6/20先天性肺畸形中检测到7种肿瘤转化相关SNV。在先前与TERT癌基因上游的5p15.33肺癌相关的区域中,发现了四种在普通人群中非常罕见的SNV。此外,我们发现了错义遗传变异,其致瘤作用是众所周知的,在RET中,FANCA和MET基因。
结论:95%的CLM基因组不稳定,其中30%与肿瘤发展有关的遗传变异,不管组织病理学如何,是恶性肿瘤的诱发因素,再加上接触致癌物,可能引发恶性肿瘤的发展,并解释CLM和肺癌之间的关联。
OBJECTIVE: To study the biological relationship between congenital lung malformations (CLMs) and malignancy.
METHODS: Biopsies of 12 CPAMs, 6 intralobar sequestrations and 2 extralobar sequestrations were analyzed through whole-genome sequencing. Blood samples from 10 patients were used to confirm or exclude somatic mosaicism. Putative somatic Single Nucleotide Variants (SNVs) were called for each malformed sample with a Panel of Normals built with control DNA samples extracted from blood. The variants were subsequently confirmed by Sanger sequencing and searched, whenever possible, in the blood samples of patients.
RESULTS: All CLMs but one presented a signature of genomic instability by means of multiple clusters of cells with gene mutations. Seven tumor transformation-related SNVs were detected in 6/20 congenital lung malformations. Four very rare in the general population SNVs were found in a region previously linked to lung cancer in 5p15.33, upstream of TERT oncogene. Furthermore, we identified missense genetic variants, whose tumorigenic role is well known, in the RET, FANCA and MET genes.
CONCLUSIONS: Genomic instability in 95% of CLMs and genetic variants linked to tumor development in 30% of them, regardless of histopathology, are predisposing factors to malignancy, that combined with exposure to carcinogens, might trigger the development of malignancy and explain the association between CLMs and lung cancer.