Background: The significance of Notch2 expression in colorectal cancer (CRC) has not been clearly investigated. We investigated the expression of Notch2 and its relationship with differentiation status and tumor stage by studying clinical CRC specimens with matched adjacent normal tissues and normal control colorectal specimens.
Methods: Immunohistochemistry, real-time polymerase chain reaction, and Western blot analysis were performed to assess the expression of Notch2 in clinical CRC specimens. Also, Notch2 levels in an induced differentiation model of CRC cell lines were investigated.
Results: It was found that Notch2 expression was decreased in cancer tissues compared with adjacent normal tissue and normal control tissues. Also, a tendency for decreased expression was observed when going from well to poorly differentiated carcinomas, as well as going from tumor, node, metastasis system stage I to stage IV. With the differentiation of colon cancer cells, the expression of Notch2 increased. To support this observation, colon cancer cell lines HT29 and SW620 were induced to differentiate in culture, and expression of Notch2 was investigated. A clear increase expression of Notch2 was observed.
Conclusions: Notch2 expression correlated closely with CRC and may play a role in tumor inhibition in colon carcinogenesis.