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arXiv 1604.02487q-bio.GN
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来自大量肿瘤基因组数据的结构化混合物的自动解卷积

Automated deconvolution of structured mixtures from bulk tumor genomic data

Theodore Roman, Lu Xie, Russell Schwartz

摘要:

动机:随着癌症研究人员逐渐认识到肿瘤内异质性的重要性,许多注意力都集中在准确分析个体患者异质性的挑战上。直接分析单细胞基因组的实验技术正在迅速改进,但它们对于大规模采样仍然不切实际。批量基因组测定仍然是人群规模研究的标准,但混淆了遗传上不同的肿瘤,基质和浸润性免疫细胞的混合物的影响。许多计算方法已经被开发来解卷积这些混合样本和重建基因同质克隆亚群的基因组学。然而,所有这样的方法,仅限于重建粗略的近似几个主要的亚群。在以前的工作中,我们表明,可以通过一种称为单纯复杂推理的策略,利用细胞混合物中的子结构来改善基因组数据的去卷积。然而,这种策略也受到从稀疏的、有噪声的测定推断混合物结构的困难的限制。结果如下:我们通过引入增强功能来自动学习亚结构化基因组混合物,特别强调全基因组拷贝数变异(CNV)数据来改进过去的工作。我们介绍的方法,更好地分解混合模型子结构的维数估计,模糊聚类,以更好地识别子结构稀疏,嘈杂的数据,和自动模型推理方法的其他关键模型参数。我们表明,这些改进导致更准确的推断细胞群体和混合比例在模拟场景。我们进一步证明了它们在识别真实肿瘤CNV数据中的混合子结构中的有效性。可用性:源代码可在http://www.cs.cmu.edu/~russells/software/WSCUnmix.zip上获得

英文摘要:

Motivation: As cancer researchers have come to appreciate the importance of intratumor heterogeneity, much attention has focused on the challenges of accurately profiling heterogeneity in individual patients. Experimental technologies for directly profiling genomes of single cells are rapidly improving, but they are still impractical for large-scale sampling. Bulk genomic assays remain the standard for population-scale studies, but conflate the influences of mixtures of genetically distinct tumor, stromal, and infiltrating immune cells. Many computational approaches have been developed to deconvolute these mixed samples and reconstruct the genomics of genetically homogeneous clonal subpopulations. All such methods, however, are limited to reconstructing only coarse approximations to a few major subpopulations. In prior work, we showed that one can improve deconvolution of genomic data by leveraging substructure in cellular mixtures through a strategy called simplicial complex inference. This strategy, however, is also limited by the difficulty of inferring mixture structure from sparse, noisy assays. Results: We improve on past work by introducing enhancements to automate learning of substructured genomic mixtures, with specific emphasis on genome-wide copy number variation (CNV) data. We introduce methods for dimensionality estimation to better decompose mixture model substructure; fuzzy clustering to better identify substructure in sparse, noisy data; and automated model inference methods for other key model parameters. We show that these improvements lead to more accurate inference of cell populations and mixture proportions in simulated scenarios. We further demonstrate their effectiveness in identifying mixture substructure in real tumor CNV data. Availability: Source code is available at http://www.cs.cmu.edu/~russells/software/WSCUnmix.zip

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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