Research Paper Advance Articles

Joint effect of RRP9 and DDX21 on development of colorectal cancer and keloid via verification of experiment

Hao Liu1, *, , Xiaoqian Chi2, *, , Ning Yang3, , Mengjie Shan1, , Yiding Xiao1, , Mingzi Zhang1, , Yan Hao1, , Shiyang Hou2, , Yabin Liu4, , Youbin Wang1, ,

  • 1 Department of Plastic Surgery, Peking Union Medical College Hospital, Beijing, China
  • 2 Department of General Surgery, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
  • 3 Department of General Surgery, The First Affiliated Hospital, Hebei Medical University, Shijiazhuang, China
  • 4 Department of General Surgery, The Fourth Affiliated Hospital, Hebei Medical University, Shijiazhuang, China
* Equal contribution

Received: May 31, 2023       Accepted: October 12, 2023       Published: November 20, 2023
How to Cite

Copyright: © 2023 Liu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Background: Colorectal cancer (CRC) is a common malignancy in the gastrointestinal tract. Keloid refers to abnormal scar tissue that forms on the skin or mucous membrane. The relationship between RRP9 and DDX21 and the two diseases is unclear.

Methods: Download the colorectal cancer dataset GSE134834, GSE206800, GSE209892 and keloid dataset GSE44270 from the GEO database. Differentially expressed genes (DEGs) were screened and weighted gene co-expression network analysis (WGCNA) was performed. The construction and analysis of protein–protein interaction (PPI) network, functional enrichment analysis, gene set enrichment analysis (GSEA). Gene expression heat map was drawn. The comparative toxicogenomics database (CTD) analysis was performed to find diseases most related to core genes. TargetScan screened miRNAs that regulated central DEGs. We conducted experimental validation using Western blotting and Polymerase Chain Reaction (PCR).

Results: In the colorectal cancer dataset and the scar tissue dataset, we identified 1380 DEGs and 1000 DEGs, respectively. The enrichment pattern for scar tissue was similar to that of colorectal cancer. We identified two core genes, RRP9 and DDX21. CTD analysis indicated that RRP9 and DDX21 are associated with proliferation, scar tissue, colorectal tumors, scleroderma, and inflammation. We found that the core genes (RRP9 and DDX21) were highly expressed in colorectal cancer and scar tissue samples, while their expression was lower in normal samples. This was further validated through Western blotting (WB) and Polymerase Chain Reaction (PCR).

Conclusions: The higher the expression of RRP9 and DDX21 in colorectal cancer and keloid, the worse the prognosis.


CRC: Colorectal cancer; GEO: gene expression omnibus; DEGs: differential epigenetic genes; WGCNA: weighted gene co-expression network analysis; PPI: protein-protein interaction; GSEA: Gene set enrichment analysis; CTD: Comparative Toxicogenomics Database; MAD: Median Absolute Deviation; TOM: topological overlap matrix; STRING: Search Tool for the Retrieval of Interacting Genes; GO: gene ontology; KEGG: Kyoto Encyclopedia of Gene and Genome; WB: western blotting; PCR: polymerase chain reaction.