Molecular Drivers of Lung Cancer in Hispanics

项目摘要 肺癌是拉美裔/拉丁裔(H/L)男性癌症死亡的主要原因，排名第二 男/L女子1.虽然H/L在全国范围内作为少数民族超过了非裔美国人，但他们占了 在癌症基因组图谱(TCGA)2中只有3%(总共149名)的患者具有特征，只有0.4%的患者- 已有的肿瘤学模型。在肺癌患者中，与高加索人相比，H/LS(1) 不吸烟者的死亡率是不吸烟者的两倍4-8；(2)更频繁地出现在晚期疾病7，9；(3) 由于缺乏适当的基因组，通常不被确定为靶向治疗的候选者 他们的肺癌的特征10-12。为了解决肺癌方面的这些差异，我们 收集163例H/L患者的肺肿瘤标本，进行外显子组测序。值得注意的是，我们 观察到的H/L肺腺癌患者KRAS和STK11突变的发生率非常低，而A EGFR突变的高流行率--WE13和其他14发现与土著有关的模式 美国血统。我们对登记的48名患者进行了研究，这些患者缺乏KRAS或EGFR 驱动RNA测序的突变以评估已知或未知的融合事件是否可能解释肺 在这个研究不足的人群中发现癌症。在48例患者标本中，有10例(21%)具有潜在性 致癌转录融合。这些患者中有一半(5)已知MET融合或表示已知 MET的致癌亚型。值得注意的是，其他五名患者样本表达了ADCK4-NUMBL融合 转录本(三份外显子15：外显子2融合和两份外显子15：外显子3融合)。脱氧核糖核酸 测序不能揭示基因融合；然而，ADCK4和NUMBL基因在 19号染色体支持ADCK4(外显子15)与NUMBL(外显子)基因间的顺式剪接假说 2)促进ADCK4-NUMBL嵌合转录本的表达。在少数几个国家也发现了类似的文字记录 细胞系，但在通过TCGA获得的大量RNA测序数据中没有观察到，这表明这些 转录本通常只在H/L患者样本中表达。基于有限文献15-18，我们 假设ADCK4与NUMBL基因间剪接驱动ADCK4-NUMBL嵌合表达 转录本和这些转录本表达具有独特生物学特性的癌蛋白。为了测试这些 假设，我们将1)确定ADCK4-NUMBL嵌合蛋白的表达如何影响细胞 生物学，2)建立新的H/L从不吸烟的患者来源的细胞系，3)探索 导致顺式剪接ADCK2-NUMBL转录本表达的机制。我们预计， 这些研究的结果将为肺癌死亡率上升的机制提供洞察力。 在不吸烟和确定新的治疗靶点的H/L中。

Project Summary Lung malignancies are the leading cause of cancer death among Hispanic/Latino (H/L) men and second among H/L women1. While H/L have surpassed African Americans as a minority nationally, they account for only 3% (149 total) of patients characterized in the Cancer Genome Atlas (TCGA)2 and only 0.4% of patient- derived oncological models in existence3. Among lung cancer patients, compared to Caucasians, H/Ls (1) have double the mortality among never-smokers4-8; (2) present more frequently with late-stage disease7, 9; (3) and are often not identified as being candidates for targeted therapy due to the lack of proper genomic characterization of their lung cancers10-12. To address these disparities with respect to lung cancer, we collected 163 lung tumor samples from H/L patients and subjected them to exome sequencing13. Notably, we observed H/L lung adenocarcinoma patients have a very low prevalence of KRAS and STK11 mutations and a high prevalence of EGFR mutations - a pattern that we13 and others14 find associated with Indigenous American ancestry. We subjected 48 patients of those patients from the registry that lacked KRAS or EGFR driver mutations to RNA sequencing to assess if known or unknown fusion-events might account for lung cancer in this understudied population. Out of the 48 patient specimens, ten (21%) harbored potential oncogenic transcript fusions. Half (5) of these patients had known MET fusions or expressed known oncogenic isoforms of MET. Notably, the other five patient specimens expressed ADCK4-NUMBL fusion transcript (three copies of Exon 15: Exon 2 fusions and two copies of Exon 15: Exon 3 fusions). DNA sequencing does not reveal gene fusion; however, the ADCK4 and NUMBL genes are aligned head-to-tail in chromosome 19 supporting the hypothesis that intergenic cis-splicing of ADCK4 (Exon 15) with NUMBL (Exon 2) drives expression of ADCK4-NUMBL chimeric transcripts. Similar transcripts have been detected in a few cell lines but are not observed in the vast RNA sequencing data available via the TCGA, suggesting that these transcripts are expressed commonly only in H/L patient samples. Based on the limited literature15-18, we hypothesize that intergenic splicing of ADCK4 with NUMBL drives expression of ADCK4-NUMBL chimeric transcripts and that these transcripts express oncoproteins with unique biological properties. To test these hypotheses, we will 1) determine how expression of ADCK4-NUMBL chimeric proteins influence cell biology, 2) establish novel patient-derived cell lines from H/L never smokers and 3) explore the mechanisms leading to the expression of cis-spliced ADCK2-NUMBL transcripts. We anticipate that the results of these studies will provide insight into the mechanisms driving the elevated lung cancer mortality among H/Ls who do not smoke and identify novel therapeutic targets.