NGS Reveals the Phylogeny of Multi-Organ Metastatic Colon Cancer and Molecular Determinants of Metastasis

Background: The clinical manifestation of metastatic colorectal cancer (mCRC) varies from patient to patient, with the underlying genetic alterations and expression profiles deceptive. We aim to investigate the phylogenetic relationships of the multi-organ mCRC and the possible biomarkers of disease progression. Methods: Whole Extron Sequencing (WES) was performed in CRC and their matched multi-organ metastases from three patients with different clinical manifestations. Sciclone calculation between individual lesions illustrated the evolutionary origins of each metastatic sites. Genomic divergence between primary and metastatic sites were identified and their potential role in the metastatic process were annotated. Following the WES results, the significantly correlated genes were validated by immunohistochemistry. Findings: The evolutionary tree showed that the distant metastasis could originated from either the primary colon cancer or the other metastatic site. Organotropism exists in both mCRC and protein levels in terms of APOB and FLNC, and a number of driver mutations potentially decide the disease progression. Moreover, the expressive change of APOB between primary CRC and CRC liver metastasis indicates worse long-term outcomes. Interpetation: Metastatic routes of multi-organ mCRC are highly heterogeneous. We identified previously unreported gene alterations might facilitate metastatic and organotropic progression, providing potential biomarkers for diagnosis and treatment. Funding Statement: This work was funded by the National Science and Technology Major Project of China (2018ZX10723204, 2018ZX10302205), the National Natural Science Foundation of China (81874070, 81871991, 81772595), Guangzhou Science and Technology Plan Projects (Health Medical Collaborative Innovation Program of Guangzhou) (201803040019, 201400000001-4). Declaration of Interests: The authors have no conflict of interest to declare. Ethics Approval Statement: This study was approved by the ethical committee of our institute (GZR2019-014).