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ABSTRACT: Background
Metastasis is the primary cause of cancer mortality accounting for 90% of cancer deaths. Our understanding of the molecular mechanisms driving metastasis is rudimentary.Results
We perform whole exome sequencing (WES), RNA sequencing, methylation microarray, and immunohistochemistry (IHC) on 8 pairs of non-small cell lung cancer (NSCLC) primary tumors and matched distant metastases. Furthermore, we analyze published WES data from 35 primary NSCLC and metastasis pairs, and transcriptomic data from 4 autopsy cases with metastatic NSCLC and one metastatic lung cancer mouse model. The majority of somatic mutations are shared between primary tumors and paired distant metastases although mutational signatures suggest different mutagenesis processes in play before and after metastatic spread. Subclonal analysis reveals evidence of monoclonal seeding in 41 of 42 patients. Pathway analysis of transcriptomic data reveals that downregulated pathways in metastases are mainly immune-related. Further deconvolution analysis reveals significantly lower infiltration of various immune cell types in metastases with the exception of CD4+ T cells and M2 macrophages. These results are in line with lower densities of immune cells and higher CD4/CD8 ratios in metastases shown by IHC. Analysis of transcriptomic data from autopsy cases and animal models confirms that immunosuppression is also present in extracranial metastases. Significantly higher somatic copy number aberration and allelic imbalance burdens are identified in metastases.Conclusions
Metastasis is a molecularly late event, and immunosuppression driven by different molecular events, including somatic copy number aberration, may be a common characteristic of tumors with metastatic plasticity.
SUBMITTER: Lee WC
PROVIDER: S-EPMC7640699 | biostudies-literature | 2020 Nov
REPOSITORIES: biostudies-literature
Lee Won-Chul WC Reuben Alexandre A Hu Xin X McGranahan Nicholas N Chen Runzhe R Jalali Ali A Negrao Marcelo V MV Hubert Shawna M SM Tang Chad C Wu Chia-Chin CC Lucas Anthony San AS Roh Whijae W Suda Kenichi K Kim Jihye J Tan Aik-Choon AC Peng David H DH Lu Wei W Tang Ximing X Chow Chi-Wan CW Fujimoto Junya J Behrens Carmen C Kalhor Neda N Fukumura Kazutaka K Coyle Marcus M Thornton Rebecca R Gumbs Curtis C Li Jun J Wu Chang-Jiun CJ Little Latasha L Roarty Emily E Song Xingzhi X Lee J Jack JJ Sulman Erik P EP Rao Ganesh G Swisher Stephen S Diao Lixia L Wang Jing J Heymach John V JV Huse Jason T JT Scheet Paul P Wistuba Ignacio I II Gibbons Don L DL Futreal P Andrew PA Zhang Jianhua J Gomez Daniel D Zhang Jianjun J
Genome biology 20201104 1
<h4>Background</h4>Metastasis is the primary cause of cancer mortality accounting for 90% of cancer deaths. Our understanding of the molecular mechanisms driving metastasis is rudimentary.<h4>Results</h4>We perform whole exome sequencing (WES), RNA sequencing, methylation microarray, and immunohistochemistry (IHC) on 8 pairs of non-small cell lung cancer (NSCLC) primary tumors and matched distant metastases. Furthermore, we analyze published WES data from 35 primary NSCLC and metastasis pairs, a ...[more]