相关实验视频
Updated: Jan 24, 2026

07:50
Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer
Published on: September 18, 2020
6.1K
在癌症患者中全基因组无细胞DNA碎片化
Stephen Cristiano1,2, Alessandro Leal1, Jillian Phallen1
1The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Nature
|May 31, 2019
概括
分析无细胞DNA碎片模式为癌症检测提供了一种新的非侵入性方法. 这种方法在识别各种癌症及其起源方面具有高度的敏感性和特异性,有助于早期诊断.
科学领域:
- 基因组学
- 分子生物学
- 生物化学
背景情况:
- 血液中的无细胞DNA (cfDNA) 是癌症诊断的一个有前途的非侵入性工具.
- 了解cfDNA的起源和分子特性对于其临床应用至关重要.
- 目前用于cfDNA分析的方法在全面描述其特征方面存在局限性.
研究的目的:
- 开发和验证一种分析全基因组cfDNA碎片化模式的方法.
- 评估cfDNA碎片化资料在癌症检测和来源识别中的有用性.
- 评估碎片化分析和基于突变的cfDNA分析的综合性能.
主要方法:
- 开发一种评估全基因组cfDNA分裂模式的方法.
- 对236名癌症患者 (乳腺癌,结肠直肠癌,肺癌,卵巢癌,胰腺癌,胃癌,胆道癌) 和245名健康患者的cfDNA碎片化概况的分析.
- 应用一种包含碎片化特征的机器学习模型,用于癌症检测和起源预测.
主要成果:
- 健康个体表现出cfDNA碎片化模式,反映出白细胞核细胞模式,与癌症患者不同.
- 机器学习模型在检测七种癌症类型时获得了高灵敏度 (57%~99%) 和98%的特异性 (AUC 0.94).
- 在75%的病例中,碎片化分析确定了癌症组织的起源,与突变检测相结合的分析达到91%的癌症检测.
结论:
- 全基因组cfDNA碎片化模式为癌症提供了宝贵的见解.
- 这种方法作为非侵入性癌症查,早期检测和监测的原则证明.
- 这种方法增强了cfDNA的诊断潜力,补充了现有的基于突变的分析.
相关概念视频
Genome-wide Association Studies-GWAS
15.4K
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
GWAS does not require the identification of the target gene involved in...
15.4K
Genomics
39.9K
Genomics is the science of genomes: it is the study of all the genetic material of an organism. In humans, the genome consists of information carried in 23 pairs of chromosomes in the nucleus, as well as mitochondrial DNA. In genomics, both coding and non-coding DNA is sequenced and analyzed. Genomics allows a better understanding of all living things, their evolution, and their diversity. It has a myriad of uses: for example, to build phylogenetic trees, to improve productivity and...
39.9K
Genomic DNA in Prokaryotes
48.4K
The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Genomic Diversity in Bacteria
Although bacterial genomes are much...
48.4K
Genomic DNA in Eukaryotes
52.7K
Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the nucleus. To achieve this, DNA is tightly wound around proteins called histones, which are packaged into nucleosomes that are joined by linker DNA and coil into chromatin fibers. Additional fibrous proteins further compact the chromatin, which is recognizable as chromosomes during certain phases of cell division.
52.7K
Habitat Fragmentation
21.2K
Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land conversion, as well as slower geological processes leading to changes in the physical environment, are the two leading causes of habitat fragmentation. The fragmentation process typically follows the same steps: perforation, dissection, fragmentation, shrinkage, and attrition.
21.2K
Genomic Imprinting and Inheritance
36.9K
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
36.9K

