Figure 1.

CD45 expression is increased in surviving CRC epithelial cells after CRT. (A) Identification of potential therapy resistance-related genes using gene expression data from patients with CRC. The DEG list identified in residual tumors after CRT (upregulated: 116, downregulated: 64, |fold change| ≥2, p-value< 0.05) was compared with that of metastatic tumors (upregulated: 311, downregulated: 222, |fold change| ≥1.5, p-value< 0.0005). In patients with rectal cancer who underwent preoperative CRT (GSE93375), DEGs were obtained by comparing the residual primary cancer tissues after CRT (n = 9) with the pretreated tissues (n = 13). In patients with colon cancer (GSE68468), DEGs were acquired by comparing nonmetastatic colon cancer (n = 183) and metastatic colon cancer (n = 58) residing in the liver or lung. (B and C) RT-qPCR validation of therapy resistance genes in multiple CRC cells at 48 h after (B) 5-FU or (C) radiation treatment. The mRNA expression levels of the indicated genes are presented in a heatmap with p-values. (D) The scRNA-seq data of CRC tumors were obtained from the GEO web server (GSE81861). Distribution of the expression of PTPRC and epithelial and leukocyte markers in the indicated subsets. (E) Triple-staining FACS analyses were performed in CRC tumor tissues as follows: (i) CD3, EpCAM, and CD45; (ii) CD4, EpCAM, and CD45; and (iii) CD8, EpCAM, and CD45. The dot blot shows the percentage of the indicated cellular population in tissues from patients with CRC (P#20051910, P#20051914, P#20052910, and P#20052914). (F) H&E and immunofluorescence staining of normal and cancerous tissues obtained from patients with CRC. (G) RT-qPCR and Western blot analysis of CD45 (PTPRC) expression in various CRC cells (n = 3 per group). (H) FACS plots show the increase in levels of the CD45 protein in CRC epithelial cells at 48 h after 5-FU or radiation treatment. ** and *** indicate p-values < 0.01 and < 0.001, respectively.