A study evaluating TIMP1 as a metastasis associated biomarker and its role in lung adenocarcinoma metastasis

• Main Authors: Fang-JuLiu, 劉芳菊
• Other Authors: Pao-Chi Liao
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/05110838193813084059

碩士 === 國立成功大學 === 環境醫學研究所 === 101 === Lung cancer is the leading cause of cancer death. Most lung cancer patients are diagnosed late; many while having distant metastatic disease; the survival rate drops to around 3.9%. Thus, a biomarker for early diagnosis of metastasis has important clinical implications and is important for anti-cancer drug discovery. The tissue inhibitor of metalloproteinases 1 (TIMP1) is a documented cancer cell invasion-related protein (by previous research). This study will focus on the role of TIMP1 in lung adenocarcinoma metastasis and its clinical implications. In the “mechanism” study, CL1-0 (low invasiveness) and CL1-5 (high invasiveness) cell lines were used as models. In the gelatin zymography test, there were four MMPs with statistically differential activity; this includes MMP2 (CL1-5：CL1-0=3.34) and MMP9 (CL1-0：CL1-5=2.31). MMP2 was of a higher level in CL1-5 (protein level-3.35 fold, mRNA level-6.12 fold). In contrast, MMP9 was of a higher level in CL1-0 (protein level-1.59 fold, mRNA level-3.13 fold). The difference in mRNA levels of TIMP1 for CL1-5 over CL1-0 was 80.94. Because of the higher expression of TIMP1 in CL1-5, we decreased the TIMP1 level in CL1-5 to serve as a model that would allow us to observe the influence on MMP2 and MMP9. Interestingly, the activity of MMP2 was significantly reduced (4.21 fold) but not MMP9 (1.28 fold). The same trend was observed in the protein and mRNA levels of MMP2 (decreased) and MMP9 (unchanged). Tissue samples (N=85) were studied and there was a statistically significant differential expression (p 〈 0.05) in distant metastasis (I~III and IV), each stage (I, II, III, IV), and lymph node metastasis stages (N0, N1, N2, N3) using tissue microarray (TMA) and immunohistochemistry (IHC). Furthermore, before having enzyme linked immunosorbent assays (ELISA) test, a differential expression of TIMP1 between the plasma of lung adenocarcinoma patients (N=7) and healthy controls (N=2) was observed using Western blot. The data showed that TIMP1 had higher levels in patients than control samples. Based on the results, we tested the plasma samples from 188 patients and 94 healthy controls. TIMP1 was higher in patients, overall stage I (N=97), early stage (I+II, N=129) and late stage (III+IV, N=59). We suggest that TIMP1 is a potential biomarker for the detection of metastasis in the tissue of lung adenocarcinoma patients and promotes cell metastasis through the regulation of MMP2.