Clinical significance of matrix metalloproteinase-7 and Ets-1 gene expression in patients with lung cancer

Background. Matrix metalloproteinase-7 (MMP-7) is a member of the MMP family and has a wide variety of substrate spectra. Ets domain transcription factors are reported to play an important role in carcinoma invasion and metastasis. The regulatory role of Ets-1 has been shown in several MMPs. We have hypothesized that MMP-7 and Ets-1 mRNA levels could be predictors of the development and invasion of lung cancer. Methods. The study included 73 lung cancer cases. The mRNA levels were quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR) using a LightCycler. Results. No significant difference in MMP-7 and Ets-1 mRNA levels was found among gender, age, and pathological subtype. The MMP-7 mRNA levels were elevated in tumor tissues from stage II-IV lung cancer (1.629 +/- 2.267) compared to those from stage I lung cancer (0.762 +/- 1.463) (P = 0.0290). There was a tendency toward higher MMP-7 mRNA expression levels in tumors with lymph node metastasis (1.728 +/- 2.432) compared to those without lymph node metastasis (1.141 +/- 1.838) (P = 0.1076). Thus, MMP-7 mRNA levels may serve as a marker of higher stages in lung cancer. No significant difference in Ets-1 mRNA levels was found among clinical stages and T-status. The Ets-1 mRNA levels were elevated in tumors from N2 patients (7.512 +/- 13.306) compared to those from N0 patients (2.525 +/- 4.719) (P = 0.0209). Ets-1 mRNA levels showed a positive correlation with MMP-7 expression (P = 0.0042). Conclusions. Using the LightCycler RT-PCR assay, the determination of MMP-7 and Ets-1 mRNA levels might provide a potential marker for advanced lung cancer. However, further studies and a longer follow-up are needed to confirm the impact of MMP-7 in the biological behavior of the tumor. (C) 2001 Elsevier Science.