10562

OLFM4

olfactomedin 4;OLFM4;olfactomedin 4

G-CSF-stimulated clone 1 protein|antiapoptotic protein GW112|olfactomedin-4

13q14.3

protein-coding

Distant metastasis of colorectal cancer (CRC) occurs mainly in the liver and is the major cause of death. This study explored the overexpression of liver metastasis-associated mRNAs in human CRC by using a well-established, weighted enzymatic chip array platform. Analysis of 10 CRC tissue specimens compared with their normal adjacent tissues revealed that ATP2A2, ELAVL4, hTERT, KCTD2, MUC1, OLFM4, S100B, and TM4SF4 genes were upregulated (gene expression ratio of cancer tissue to paired normal tissue was >2) by microarray and bioinformatics analysis. A gene chip including eight candidate genes was constructed to investigate the circulating tumor cells in blood specimens of 103 preoperative CRC patients and further validated by reverse transcriptase-polymerase chain reaction. Liver metastasis was significantly correlated with overexpression of S100B (p=0.001, OR=9.217), TM4SF3 (p=0.011, OR=4.385), and OLFM4 (p=0.015, OR=3.438). These results suggest that S100B, TM4SF3, and OLFM4 overexpression may affect metastatic behavior of tumor cells in Taiwanese CRC patients.

Olfactomedin 4 (OLFM4) is highly expressed in gastrointestinal cancers and has an anti-apoptotic function. The roles of OLFM4 in tumor growth and metastasis and how it functions in these processes remain elusive. We investigated the function of OLFM4 in tumor growth and metastasis using B16F10 mouse melanoma cells as an experimental system. Our results showed that OLFM4 had no positive effect on cell viability or cell cycle progression in B16F10 cells. However, it significantly suppressed the tumorigenicity of B16F10 cells, i.e., intradermal primary tumor growth and lung metastasis. OLFM4 also suppressed the migration and invasion of B16F10 cells in vitro. For further insight into the mechanisms underlying OLFM4-mediated suppression of tumor progression, we examined the effect of OLFM4 on the expression of integrin and matrix metalloproteinase (MMP), both of which are involved in tumor progression. Overexpression of OLFM4 clearly reduced the expression levels of integrin alpha1, integrin alpha4, integrin alpha5, integrin alpha6, and MMP9. Moreover, forced expression of MMP9 attenuated the inhibitory activity of OLFM4 on migration and invasiveness. Our findings provide the experimental evidence that OLFM4 may function as a tumor suppressor and an anti-metastatic gene during tumor progression.