Expression Of Matrix Metalloproteinase-28 In Non-small Lung Cancer And Effect Of Antisense Ligodeoxynucleotide On Cell Biological Character Of Lung Cancer Cell A549

Lung cancer is the commonest cause of cancer death in the world. Non-small cell lung cancer (NSCLC) accounts for 75-80% of all new cases of lung cancer and the outcome of patients with NSCLC remains poor. Invasion and metastasis is one of the most important biological features of NSCLC and the key factor for survival of patients. Sensitive and specific biomarkers are required to predict which patients have more aggressive disease because these patients could benefit from adjuvant radiation therapy or chemotherapy and close monitoring for disease recurrence.Matrix metalloproteinases (MMPs) play a central role in many physiological or pathological functions, such as development, inflammation, tissue healing, anginogenesis, and tumor invasion. These enzymes have their ability to degrade all major protein components of the extracellular matrix (ECM) and basement membranes. MMP-28 (epilysin), structurally belonging to the MMP-19 subfamily, may represent the newest MMPs member and is expressed in a variety of normal and carcinoma tissues, such as pancreatic adenocarcinoma, ovarian carcinoma, and colon adenocarcinoma. However, studies suggest that MMP-28 expression status and biological role may differ among cancers. Expression of MMP-28 and its biological role in NSCLC has not been evaluated so far. To assess MMP-28 plays a role in NSCLC, we firstly examined the expression pattern of MMP-28 transcript in surgical specimens of tumor tissues and para-cancerous tissues by reverse transcript polymerase chain reaction (RT-PCR) and in situ hybridization. Distribution of MMP-28 protein was also analyzed by Western blot and IHC. To explore its possible functions, a NSCLC cell line A549 was subjected to specific inhibition of MMP-28 by antisense oligodeoxynucleotide (AODN) transfection. RT-PCR and Western blot were used to evaluate mRNA and protein level of MMP-28. The proliferative status of cells was measured by using methabenzthiazuron (MTT) assay and soft-agar colony formation assay. We also evaluated the therapeutic effect of AODN injection cells under skin in nude mice.The main results were as follows:1. The expression of MMP-28 mRNA and protein in NSCLC was significantly higher than para-cancerous normal tissues (P<0.01). Expression of MMP-28 in NSCLC significantly correlated with TNM stage, differentiation and lymphatic metastasis (P<0.05), but not sex, age, tumor diameter and histology (P>0.05).2. There was significant correlation between MMP-28 expression and MVD of NSCLC (P<0.01).3. The proliferative status and invasive power of A549 were inhibited significantly after antisense MMP-28 gene was transfected in vivo and in vitro.The main conclusions were as follows:1. MMP-28 might play an important role in the development, invasion and metastasis of NSCLC.2. Increased MMP-28 expression contributes to angiogenesis in NSCLC.3. MMP-28 might be a promising molecular target for treatment of NSCLC.