Copy number variation is highly correlated with differential gene expression: a pan-cancer study

• Published in: BMC medical genetics Vol. 20; no. 1; pp. 175 - 14
• Main Authors: Shao, Xin, Lv, Ning, Liao, Jie, Long, Jinbo, Xue, Rui, Ai, Ni, Xu, Donghang, Fan, Xiaohui
• Format: Journal Article
• Language: English
• Published: London BioMed Central 09.11.2019; BioMed Central Ltd; BMC
• Subjects: Biochemistry; Biomedical and Life Sciences; Biomedicine; Cancer; Cancer genetics; Cancer research; Cell Line, Tumor; Computational Biology; Concordance; Copy number variation; Cytogenetics; Development and progression; Differential gene expression; DNA Copy Number Variations; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Function; Genes; Genetic aspects; Genetic research; Human Genetics; Humans; Neoplasms - genetics; Neoplasms - metabolism; Neoplasms - pathology; Pan-cancer; Proteolysis; Reproducibility of Results; Research Article; Statistical genetics; Transcription (Genetics); Tumors; Copy number variation; Differential gene expression; Pan-cancer; Concordance
• ISSN: 1471-2350; 1471-2350
• DOI: 10.1186/s12881-019-0909-5

Background Cancer is a heterogeneous disease with many genetic variations. Lines of evidence have shown copy number variations (CNVs) of certain genes are involved in development and progression of many cancers through the alterations of their gene expression levels on individual or several cancer types. However, it is not quite clear whether the correlation will be a general phenomenon across multiple cancer types. Methods In this study we applied a bioinformatics approach integrating CNV and differential gene expression mathematically across 1025 cell lines and 9159 patient samples to detect their potential relationship. Results Our results showed there is a close correlation between CNV and differential gene expression and the copy number displayed a positive linear influence on gene expression for the majority of genes, indicating that genetic variation generated a direct effect on gene transcriptional level. Another independent dataset is utilized to revalidate the relationship between copy number and expression level. Further analysis show genes with general positive linear influence on gene expression are clustered in certain disease-related pathways, which suggests the involvement of CNV in pathophysiology of diseases. Conclusions This study shows the close correlation between CNV and differential gene expression revealing the qualitative relationship between genetic variation and its downstream effect, especially for oncogenes and tumor suppressor genes. It is of a critical importance to elucidate the relationship between copy number variation and gene expression for prevention, diagnosis and treatment of cancer.