Objective  To test the expression levels of matrix metalloproteinases-7 mRNA(MMP-7), solubleMHC class I-related chain A(sMICA), vascular endothelial growth factor(VEGF) in the peripheral blood oflung cancer patients and determine their relationships with the invasion and metastasis and correspondingclinical significance.

Methods  The expression of MMP-7 mRNA was determined by reverse transcriptionpolymerasechain reaction (RT-PCR) and the levels of sMICA, VEGF were measured with enzymelinked-immunosorbent assay(ELISA). Totally 110 lung cancer patients were regarded as the experimentalgroup and 40 health persons as the control group.

Results  Compared with the control group, the levelsof MMP-7 mRNA, sMICA and VEGF in the experimental group were significantly increased (P<0.05).The overexpression of MMP-7 mRNA in lung cancer patients were related to clinical stages P<0.05),the high levels of VEGF were related to histopathological types as well as histological grades (P<0.05).The levels of sMICA had a perfect positive correlation with the levels of MMP-7 mRNA and VEGF,meanwhile, the overexpression of MMP-7 mRNA was favorably correlated to the high levels of VEGF in the peripheral blood of lung cancer patients(P<0.05); the levels of MMP-7 mRNA, sMICA and VEGF weresignificantly decreased by effective treatment including surgery and chemotherapy(P<0.05); the increasedexpressions of MMP-7 mRNA, sMICA and VEGF were found in lung cancer patients with recurrence andmetastasis(P<0.05).

Conclusion  MMP-7 mRNA, sMICA and VEGF which participate in the compositionof the tumor metastasis microenvironment might have an association with occurrence, development, invasionand metastasis of lung cancer.