Transcriptome analysis of colorectal cancer liver metastasis: The importance of long non-coding RNAs and fusion transcripts in the disease pathogenesis.

Background: Despite several attempts to define the many genomic aspects of colorectal cancer liver metastasis (CRC-LM), there is still a lack of a complete and accurate picture of the cancer transcriptome and its function in the generation of metastasis.

Methods: Cancer Genome Atlas Sequence Read Archive (SRA) was used to get RNA sequencing data for CRC-LM and primary CRC. The CDseqR deconvolution method followed by the edgeR statistical approach was employed to accurately find differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA) was used to determine the long non-coding RNA (lncRNA) and mRNA pairs in CRC-LM etiology. Three alternative methods were used to explore fusion transcripts to anticipate the potential driver chimeras.

Results: Multiple cancer-related pathways were enriched in the up-regulated genes, including cell cycle, DNA replication, and RNA transport. SPP1 was the most up-regulated gene important in the cellular proliferation and migration and CCDC152 was the most down-regulated gene known in the metastatic spread of CRC. There were seven distinct lncRNAs discovered, two of which were novel (LOC107984834 and LOC107985040) and associated with metastatic related pathways such as the extracellular matrix-receptor interaction. Overall survival analysis demonstrated that SPP1 and LOC107985040 were significantly associated with poor prognosis outcomes. Seven new fusion transcripts were found in seven CRC-LM patients (22.5%) anticipated to have potential driver functions in cancer.

Conclusion: The newly discovered dysregulated genes and other transcriptome abnormalities could contribute to a better understanding of the CRC-LM underlying mechanism, leading to the development of new diagnostic, prognostic, and therapeutic molecular options for personalized medicine.