Roles of osteopontin and matrix metalloproteinase-7 in occurrence, progression, and prognosis of nonsmall cell lung cancer

Abstract

Background: This study detected osteopontin (OPN) and matrix metalloproteinase-7 (MMP-7) expressions to explore the roles of OPN and MMP-7 in the occurrence, progression, and prognosis of nonsmall cell lung cancer (NSCLC). Materials and Methods: A retrospective study was conducted on NSCLC tissues (n = 152; case group) and adjacent nonneoplastic lung parenchyma (adjacent to tumor >5 cm; n = 152; control group) collected from 152 NSCLC patients. The protein expressions of OPN and MMP-7 were detected by immunohistochemistry. OPN and MMP-7 messenger RNA (mRNA) expressions were detected by reverse transcription polymerase chain reaction (RT-PCR). Results: The protein and mRNA expressions of OPN and MMP-7 in NSCLC tissues were evidently higher than those in adjacent nonneoplastic lung parenchyma (all P < 0.05). OPN protein and mRNA expression were associated with the degree of differentiation, tumor node metastasis (TNM) staging, and lymph node metastasis in NSCLC (all P < 0.05). MMP-7 protein expression was associated with TNM staging and lymph node metastasis (both P < 0.05) while MMP-7 mRNA expression was associated with the degree of differentiation, TNM staging, and lymph node metastasis (all P < 0.05). A significantly positive relativity was revealed between OPN expression and MMP-7 expression (protein: r = 0.789, P < 0.001; mRNA: r = 0.377, P < 0.001). Lymph node metastasis, TNM staging, OPN, and MMP-7 protein expressions were independent risk factors for the prognosis of NSCLC (all P < 0.05). Conclusion: High MMP-7 and OPN protein expressions are closely related to the occurrence, progression, and prognosis of NSCLC, and can be served as unfavorable prognostic factors for NSCLC.

Key words: Lymph node metastasis, matrix metalloproteinase-7 (MMP-7), nonsmall cell lung cancer (NSCLC), osteopontin (OPN), prognosis, tumor node metastasis (TNM) staging