Gene expression profile of human colorectal cancer identified NKTR as a biomarker for liver metastasis.

SAM yielded showed 256 up-regulated and 224 down-regulated differentially differently expressed genes. Seven genes were identified by using ADA, tools and four genes were verified by using qRT-PCR. Three genes (metastasis associated lung adenocarcinoma transcript 1 (MALAT1), nuclear factor I/B (NKTR), and nuclear factor I/B (NFIB)) showed a statistically significant considerabley difference between CRC with and liver metastasis and CRC without liver metastasis. Immunohistochemical analysis showed that NKTR expression was much lower in primary CRC with liver metastasis than that in primary CRC without liver metastasis. The NKTR protein plays a role in the lytic function of natural killer (NK) cells and it has been rarely studied in the CRC. The down-regulation of NKTR by shRNA interference in CRC cells increased cell proliferation, migration, and invasion .