Identification of the retinoic acid-inducible Gprc5a as a new lung tumor suppressor gene
Identification of the retinoic acid-inducible Gprc5a as a new lung tumor suppressor gene
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DOI：
10.1093/jnci/djm208
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发表时间：
2007-11-21
影响因子：
10.3
通讯作者：
Lotan, Reuben
中科院分区：
文献类型：
--
作者：
Tao, Qingguo;Fujimoto, Junya;Lotan, Reuben
背景肺癌的发生是通过多种遗传和表观遗传学改变，包括肿瘤抑制基因的失活。方法采用同源重组技术构建Gprc 5a基因敲除小鼠模型，通过肉眼观察和1 ~ 2岁小鼠胚胎及肺组织的显微组织学分析，研究Gprc 5a基因敲除小鼠的表型。通过逆转录-聚合酶链反应分析了18例人肺肿瘤和邻近正常组织的手术标本中GPRC 5A mRNA的表达，并分析了来自186例各种组织学类型的肺肿瘤组织和17例正常肺样本的先前发表的数据。用GPRC 5A表达载体或对照载体转染人胚肾、人非小细胞肺癌和小鼠肺腺癌细胞，并测定半固体培养基中的集落形成。结果纯合子基因敲除小鼠在1- 2岁时比杂合子（11%腺瘤）或野生型（10%腺瘤）小鼠发生更多的肺肿瘤（发病率：76%腺瘤和17%腺癌）。在大多数（18例中的11例[61%]）人肺肿瘤中，人GPRC 5A mRNA水平低于邻近正常组织。腺癌（n = 139）、鳞状细胞癌（n = 21）、小细胞肺癌（n = 6）和类癌（n = 20）组织中GPRC 5A mRNA的平均表达分别为46.2%（P= 0.014）、7.5%（P= 0.0001）和7.5%（P = 0.001）。
Background Lung cancers develop via multiple genetic and epigenetic changes, including inactivation of tumor suppressor genes. We previously cloned human G protein-coupled receptor family C type 5A (GPRC5A), whose expression is suppressed in some human lung carcinoma cells, and its mouse homolog Gprc5a.Methods We generated Gprc5a knockout mice by homologous recombination and studied their phenotype by macroscopic observation and microscopic histologic analysis of embryos and lungs of 1- to 2-year-old mice. GPRC5A mRNA expression was analyzed by reverse transcription-polymerase chain reaction in surgical specimens of 18 human lung tumors and adjacent normal tissues and by analyzing previously published data from 186 lung tumor tissues of a variety of histologic types and 17 normal lung samples. Human embryonic kidney, human non-small-cell lung cancer, and mouse lung adenocarcinoma cells were transfected with a GPRC5A expression vector or a control vector, and colony formation in semisolid medium was assayed. Statistical tests were two-sided.Results Homozygous knockout mice developed many more lung tumors at 1- 2 years of age ( incidence: 76% adenomas and 17% adenocarcinomas) than heterozygous (11% adenomas) or wild-type (10% adenomas) mice. Human GPRC5A mRNA levels were lower in most ( 11 of 18 [61%]) human lung tumors than in adjacent normal tissues. The mean GPRC5A mRNA level in adenocarcinoma (n = 139), squamous cell carcinoma ( n = 21), small-cell lung cancer ( n = 6), and carcinoid ( n = 20) tissues was 46.2% (P=.014), 7.5% ( P