The 630-kb lung cancer homozygous deletion region on human chromosome 3p21.3: identification and evaluation of the resident candidate tumor suppressor genes. The International Lung Cancer Chromosome 3p21.3 Tumor Suppressor Gene Consortium.
The 630-kb lung cancer homozygous deletion region on human chromosome 3p21.3: identification and evaluation of the resident candidate tumor suppressor genes. The International Lung Cancer Chromosome 3p21.3 Tumor Suppressor Gene Consortium.
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发表时间：
2000-11
期刊：
影响因子：
11.2
通讯作者：
M. Lerman;J. Minna
中科院分区：
文献类型：
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作者：
M. Lerman;J. Minna
我们使用重叠和巢式纯合缺失，重叠群构建，基因组测序，物理和转录图谱，以进一步确定一个约630 kb的肺癌纯合缺失区，在染色体3p21.3上携带一个或多个肿瘤抑制基因（TSG）。这个位置是通过在肿瘤、癌细胞系和肺癌和乳腺癌前病变中的体细胞遗传图谱确定的，包括发现几个纯合缺失。分子手动方法和计算预测的结合使我们能够检测，分离，表征和注释一组25个基因，这些基因可能构成了这一约630 kb序列中完整的蛋白质编码基因。这些基因中的19个亚组被发现在约370-kb的缺失重叠区域内。该区域进一步细分嵌套200 kb乳腺癌纯合缺失成两个基因集：8个基因位于近端约120 kb的片段和11个基因位于远端约250 kb的片段。通过计算方法对这19个基因进行了广泛的分析，并通过手动方法对肺癌中的表达缺失和突变进行了测试，以从该组中鉴定候选TSGs。在非小细胞肺癌（CACNA 2D 2/alpha 2delta-2、SEMA 3B [以前称为SEMA（V）、BLU和HYAL 1]）或小细胞肺癌（SEMA 3B、BLU和HYAL 1）细胞系中，有四种基因表现出表达缺失或mRNA水平降低。我们发现其中6个基因具有两个或更多个氨基酸序列改变突变，包括BLU，NPRL 2/Gene 21，FUS 1，HYAL 1，FUS 2和SEMA 3B。然而，在肺癌样本中，测试突变的19个基因中没有一个显示出频繁（>10%）的突变率。这使我们排除了该区域中的几个基因作为散发性肺癌的经典肿瘤抑制因子。另一方面，该位置的推定肺癌TSG可能是由肿瘤获得性启动子超甲基化灭活的，或者属于一类新的单倍不足基因，其在半合子（+/-）状态下易患癌症，但在肿瘤中的剩余野生型等位基因中不显示第二突变。我们讨论的背景下，新的和经典的癌症基因模型，适用于肺癌发生的数据。通过基因转移和基因破坏策略对关键基因进行进一步的功能测试，应该可以鉴定出推定的肺癌TSG（s），LUCA，对大约630-kb序列的分析也提供了一个机会，以探测和了解这个相对基因丰富的区域的基因组结构，进化和功能组织。
We used overlapping and nested homozygous deletions, contig building, genomic sequencing, and physical and transcript mapping to further define a approximately 630-kb lung cancer homozygous deletion region harboring one or more tumor suppressor genes (TSGs) on chromosome 3p21.3. This location was identified through somatic genetic mapping in tumors, cancer cell lines, and premalignant lesions of the lung and breast, including the discovery of several homozygous deletions. The combination of molecular manual methods and computational predictions permitted us to detect, isolate, characterize, and annotate a set of 25 genes that likely constitute the complete set of protein-coding genes residing in this approximately 630-kb sequence. A subset of 19 of these genes was found within the deleted overlap region of approximately 370-kb. This region was further subdivided by a nesting 200-kb breast cancer homozygous deletion into two gene sets: 8 genes lying in the proximal approximately 120-kb segment and 11 genes lying in the distal approximately 250-kb segment. These 19 genes were analyzed extensively by computational methods and were tested by manual methods for loss of expression and mutations in lung cancers to identify candidate TSGs from within this group. Four genes showed loss-of-expression or reduced mRNA levels in non-small cell lung cancer (CACNA2D2/alpha2delta-2, SEMA3B [formerly SEMA(V), BLU, and HYAL1] or small cell lung cancer (SEMA3B, BLU, and HYAL1) cell lines. We found six of the genes to have two or more amino acid sequence-altering mutations including BLU, NPRL2/Gene21, FUS1, HYAL1, FUS2, and SEMA3B. However, none of the 19 genes tested for mutation showed a frequent (>10%) mutation rate in lung cancer samples. This led us to exclude several of the genes in the region as classical tumor suppressors for sporadic lung cancer. On the other hand, the putative lung cancer TSG in this location may either be inactivated by tumor-acquired promoter hypermethylation or belong to the novel class of haploinsufficient genes that predispose to cancer in a hemizygous (+/-) state but do not show a second mutation in the remaining wild-type allele in the tumor. We discuss the data in the context of novel and classic cancer gene models as applied to lung carcinogenesis. Further functional testing of the critical genes by gene transfer and gene disruption strategies should permit the identification of the putative lung cancer TSG(s), LUCA, Analysis of the approximately 630-kb sequence also provides an opportunity to probe and understand the genomic structure, evolution, and functional organization of this relatively gene-rich region.