Genetic Alterations in Lung Cancer

肺癌的基因改变

• 批准号: 8763105
• 负责人: Jonathan Scott Wiest
• 金额: $ 21.75万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8763105
• 关键词: Accounting; Amino Acids; Antibodies; CDKN2A gene; Cancer Etiology; Cancer Patient; Cancer cell line; Cause of Death; Cell Line; Cells; Cellular Stress; Cessation of life; Chromosome Arm; Chromosomes; Clinical; Colon Carcinoma; Data; Development; Disease; Disease Management; Distant Metastasis; Down-Regulation; Early Diagnosis; Environmental Risk Factor; Genes; Genetic Markers; Genetic Transcription; Health; Homeostasis; Human; Immunoprecipitation; In Vitro; Individual; Knockout Mice; Laboratories; Lead; Lung Neoplasms; Malignant Neoplasms; Malignant neoplasm of lung; Malignant neoplasm of prostate; Measures; Mutation; Newly Diagnosed; Nodule; Non-Small-Cell Lung Carcinoma; Northern Blotting; Open Reading Frames; Outcome; Pathway interactions; Patients; Peptides; Play; Polyadenylation; Population Group; Primary Neoplasm; Protein Binding; Protocols documentation; Public Health; Reaction; Relative Risks; Role; Signal Transduction; Smoker; Southern Blotting; Survival Rate; Systemic Therapy; Time; Tobacco smoking; Transcript; Tumor Biology; Tumor Cell Line; Tumor Suppressor Genes; United States; Woman; Yeasts; disorder risk; high risk; human tissue; improved; in vivo; lung small cell carcinoma; lung tumorigenesis; malignant breast neoplasm; men; mortality; mouse model; novel; outcome forecast; protein expression; screening; smoking cessation; tumor; tumorigenesis; yeast two hybrid system

Lung cancer is the leading cause of cancer related mortality in both men and women and continues to be a major health issue. More than 159,000 individuals will die from lung cancer in the coming year, more than breast, prostate and colon cancer combined. The majority of lung cancer cases is attributable to tobacco smoking and in some cases other environmental risk factors. Although the relative risk of developing lung cancer declines dramatically in smokers who quit, former smokers remain at risk for the disease. Several recent studies show that greater than 50% of newly diagnosed lung cancers occur in former smokers. It is estimated that there are approximately equal numbers of smokers and former smokers in the United States. Since smoking cessation is a major public health initiative, former smokers will increasingly account for a higher percentage of lung cancer cases. Thus, two high-risk population groups exist for lung cancer and improved disease management can be beneficial to both current and former smokers. Chromosome 9p genetic alterations occur frequently and often include the p16/CDKN2 locus. However, we identified a region of homozygous deletion on the short arm of chromosome 9p at the marker D9S126 and proposed the existence of a tumor suppressor gene important in lung tumorigenesis in this region. We refined the region of deletion by analyzing 30 non-small cell lung cancer and 12 small cell lung cancer cell lines by screening with 55 genetic markers to identify new regions of homozygous deletion on chromosome 9p. Three novel non-contiguous homozygously deleted regions were detected. One of these regions at D9S126 led to the identification of a gene identified as TUSC1. Multiplex PCR and Southern blot confirmed the homozygous deletion of TUSC1 and Northern blot analysis of TUSC1 demonstrated two transcripts of approximately 2 and 1.5 kb that are likely generated by alternative polyadenylation signals. Both transcripts are expressed in several human tissues and share an open reading frame encoding a peptide of 209 amino acids. Analyzing lung cancer cell lines for RNA and protein expression demonstrated down regulation of TUSC1 in several cell lines further suggesting TUSC1 may play a role in tumorigenesis. Studies using lung tumor cell lines stably transfected with TUSC1 show reduced proliferation in vitro and reduced tumor formation in vivo. Taken together, these data suggest that chromosome 9p may contain other tumor suppressor genes important in lung tumorigenesis and that TUSC1 may be a candidate TSG. Recent studies utilized yeast two hybrid protocols and identified potential protein binding partners for TUSC1. These interactions are being validated using immunoprecipitation and will lead to information concerning the pathways in which TUSC1 interacts. Antibody development for TUSC1 will also lead to the examination of multiple human tumors to detect expression levels in the primary tumors. The expression levels can then be compared to clinical outcome to further establish TUSC1 as a tumor suppressor gene. Our laboratory has also analyzed a set of primary lung tumors and has evidence for the dysregulation of TUSC1 expression. Subsequent analysis of clinical outcomes should yield important information concerning the role of TUSC1 in tumorigenesis.

肺癌是男性和女性癌症相关死亡的主要原因，并且仍然是一个主要的健康问题。未来一年将有超过15.9万人死于肺癌，超过乳腺癌、前列腺癌和结肠癌死亡人数的总和。大多数肺癌病例可归因于吸烟，在某些情况下可归因于其他环境风险因素。虽然戒烟者患肺癌的相对风险大大降低，但曾经吸烟的人仍然有患肺癌的风险。最近的几项研究表明，超过50%的新诊断的肺癌发生在前吸烟者中。据估计，在美国，吸烟者和戒烟者的人数大致相等。由于戒烟是一项重大的公共卫生倡议，前吸烟者在肺癌病例中所占的比例将越来越高。因此，存在两个肺癌高危人群，改善疾病管理对现在和以前的吸烟者都是有益的。染色体9p遗传改变经常发生，通常包括p16/CDKN2位点。然而，我们在染色体9p短臂上的标记D9S126上发现了一个纯合缺失区域，并提出在该区域存在一个在肺肿瘤发生中重要的肿瘤抑制基因。我们对30例非小细胞肺癌和12例小细胞肺癌细胞系进行了55个遗传标记筛选，对缺失区域进行了细化，在9p染色体上发现了新的纯合缺失区域。检测到三个新的非连续纯合缺失区域。其中一个位于D9S126的区域导致鉴定出一个被鉴定为TUSC1的基因。多重PCR和Southern blot证实了TUSC1的纯合缺失，而TUSC1的Northern blot分析显示了两个大约2和1.5 kb的转录本，可能是由替代的多聚腺酰化信号产生的。这两个转录本在几种人体组织中表达，并共享一个开放阅读框，编码209个氨基酸的肽。分析肺癌细胞系的RNA和蛋白表达，发现TUSC1在一些细胞系中下调，进一步提示TUSC1可能在肿瘤发生中发挥作用。用稳定转染TUSC1的肺肿瘤细胞系进行的研究表明，TUSC1在体外降低了肿瘤的增殖，在体内降低了肿瘤的形成。综上所述，这些数据表明染色体9p可能含有其他在肺肿瘤发生中重要的肿瘤抑制基因，TUSC1可能是一个候选的TSG。最近的研究利用酵母两种杂交方案，确定了TUSC1的潜在蛋白结合伙伴。这些相互作用正在使用免疫沉淀进行验证，并将获得有关TUSC1相互作用途径的信息。针对TUSC1的抗体开发也将导致对多个人类肿瘤的检查，以检测原发肿瘤中的表达水平。然后可以将表达水平与临床结果进行比较，以进一步确定TUSC1作为肿瘤抑制基因。我们的实验室也分析了一组原发性肺肿瘤，并有证据表明TUSC1表达失调。后续的临床结果分析应该会得到关于TUSC1在肿瘤发生中的作用的重要信息。