Fig. 2.

Normal tissue-derived organoids exhibited some tumor-like features at the transcriptome level. A Expression patterns of differentially expressed genes (DEGs) of in vivo tumor and adjacent normal tissues. Colors from blue to red represent low to high expression. Short, short-term culture; Long, long-term culture. Patient number in black, blue, and orange represent cells collected from in vivo tissues, in vitro chemical-defined medium, and conditioned medium. The detail description for some of these genes can be found in Additional file 4: Table S3. Many of tumor highly specifically expressed genes were reported to play important roles in colorectal cancer metastasis and progression (such as TGFBI, SCD, TESC, CEACAM6), while some of normal tissue highly expressed genes were well-known intestinal cell-type-specific marker genes, such as SI, CA1, and PYY. B Immunostaining of CEACAM6 in the adjacent normal and tumor tissues in vivo. Scale bar, 100 μm. C Immunostaining of CEACAM6 in the in vitro normal-tissue- and tumor-derived organoids. Scale bar, 50 μm