Furthermore, significantly upregulated genes in SRCCs were enriched for epithelial-mesenchymal transition genes, and accumulation of mucin in intracytoplasm was associated with the overexpression of MUC2.
Immunohistochemical staining for MUC-1 and MUC-2 glycoproteins showed a distinct difference; lung SRCC was positive for MUC-1 but negative for MUC-2, whereas colon SRCC and colorectal-type gastric SRCC were negative for MUC-1 but positive for MUC-2.Thus, by a combination of mucin-histochemistry and MUC-1 and MUC-2 immunohistochemistry, primary lung SRCC can be distinguished from metastatic lung SRCC originating in the gastrointestinal tract.