Seven candidate genes were selected for validation based on their differential expression between metastases and primary tumors and a correlation between expression and surgical outcome: lumican; tissue inhibitor metalloproteinase 1; basic helix-loop-helix domain containing class B2; fibronectin; transmembrane 4 superfamily member 1; mitogen inducible gene 6 (MIG-6); and serpine 2.
In accordance with these observations, in GC cells co-cultured with CAFs in which Lumican had been knocked down, decreased gastric tumor growth and metastasis in vivo was apparent.
Validation of the results was performed by paired and unpaired t test in primary GCTB and corresponding metastases, which proved that the differential expression of LUM and DCN is tumor specific rather than location specific.
The possible role of the small leucine-rich proteoglycan, lumican, in the growth and metastasis of various cancer types has recently been investigated.