Active-MMP2 in cancer cell nests of oral cancer patients: correlation with lymph node metastasis

Expression of matrix metalloproteinases (MMPs)−2/-7/-9/-14 and tissue inhibitors of MMPs (TIMPs)−1/-2 in bovine cutaneous fibropapillomas associated with BPV-2 infection

Introduction

Bovine papillomaviruses −1/−2 (BPVs) are small non-enveloped double-stranded DNA viruses able to infect the skin of bovids and equids, causing development of neoplastic lesions such as bovine cutaneous fibropapillomas and equine sarcoid. Matrix metalloproteinases (MMPs) are a group of zinc-dependent endopeptidases that degrade basal membrane and extracellular matrix, whose function is essential in physiological processes such as tissue remodeling and wound healing. MMPs activity is finely regulated by a balancing with expression of tissue inhibitors of MMPs (TIMPs), a process that is impaired during tumour development. BPV infection is associated with upregulation of MMPs and /or their unbalancing with TIMPs, contributing to local invasion and impairment of extracellular matrix remodeling in equine sarcoid; however, studies regarding this topic in bovine fibropapillomas are lacking.

Methods

The aim of this study was to perform an immunohistochemical and biochemical analysis on a panel of MMPs and TIMPs in BPV-2 positive bovine cutaneous fibropapillomas vs. normal skin samples.

Results

Immunohistochemistry revealed a cytoplasmic expression of MMP-2 (15/19), a cytoplasmic and perinuclear immunoreactivity of MMP-7 (19/19) and MMP-9 (19/19), along with a cytoplasmic and nuclear pattern of MMP-14 (16/19), accompanied by a cytoplasmic expression of TIMP-1 (14/19) and TIMP-2 (18/19) in tumour samples; western blotting revealed an overexpression of MMP-2 (8/9), MMP-7 (9/9) and MMP-9 (9/9), and a decreased level of MMP-14 (9/9), TIMP-1 (9/9) and TIMP-2 (9/9) in tumour versus normal skin samples. Moreover, gelatine zymography confirmed the expression of pro-active MMP-2 (9/9) and MMP-9 (9/9) and, most importantly, indicated the presence and increased activity of their active forms (82 and 62 kDa, respectively) in tumour samples.

Discussion

This is the first study describing MMPs and TIMPs in bovine cutaneous fibropapillomas and our results suggest that their unbalanced expression in presence of BPV-2 may play a significant role in tumour development. A further analysis of supplementary MMPs and TIMPs could bring new important insights into the papillomavirus induced tumours.

Galectin-1-mediated tumor invasion and metastasis, up-regulated matrix metalloproteinase expression, and reorganized actin cytoskeletons

Galectin-1 (Gal-1) is a beta-galactose-binding lectin; its expression level has been reported to correlate with tumor progression. Gal-1 is highly expressed in the invasive front of primary tumors and in the cancer cells of metastatic lesions in the lymph nodes of patients with oral squamous cell carcinoma. However, the molecular mechanism of Gal-1 in tumor metastasis is not completely clear. We found that increased Gal-1 expression is closely associated with its high levels of invasion in lung adenocarcinoma and oral squamous cell carcinoma cell lines. Knocking down Gal-1 with small interfering RNA in highly invasive cancer cells reduced their invasion levels. Moreover, the invasion ability of poorly invasive cancer cells was significantly increased after Gal-1 overexpression of Gal-1. Mechanism studies revealed that Gal-1 promoted tumor invasion mainly by up-regulating matrix metalloproteinase (MMP)-9 and MMP-2 and by reorganizing actin cytoskeleton. Gal-1 enhanced the activation of Cdc42, a small GTPase and member of the Rho family, thus increasing the number and length of filopodia on tumor cells. Furthermore, Gal-1-overexpressing cells had higher metastatic abilities in tail vein metastasis assays in vivo. We conclude that Gal-1 is involved in tumor invasion and metastasis by increasing MMP expression and reorganizing cytoskeletons in oral cancers and lung adenocarcinoma.

Molecular pathogenesis of oral squamous cell carcinoma: implications for therapy

The development of oral squamous cell carcinoma (OSCC) is a multistep process requiring the accumulation of multiple genetic alterations, influenced by a patient's genetic predisposition as well as by environmental influences, including tobacco, alcohol, chronic inflammation, and viral infection. Tumorigenic genetic alterations consist of two major types: tumor suppressor genes, which promote tumor development when inactivated; and oncogenes, which promote tumor development when activated. Tumor suppressor genes can be inactivated through genetic events such as mutation, loss of heterozygosity, or deletion, or by epigenetic modifications such as DNA methylation or chromatin remodeling. Oncogenes can be activated through overexpression due to gene amplification, increased transcription, or changes in structure due to mutations that lead to increased transforming activity. This review focuses on the molecular mechanisms of oral carcinogenesis and the use of biologic therapy to specifically target molecules altered in OSCC. The rapid progress that has been made in our understanding of the molecular alterations contributing to the development of OSCC is leading to improvements in the early diagnosis of tumors and the refinement of biologic treatments individualized to the specific characteristics of a patient's tumor.

Tissue inhibitors of metalloproteinases (TIMPs): their biological functions and involvement in oral disease

Several families of enzymes are responsible for the degradation of extracellular matrix (ECM) proteins during the remodeling of tissues. An important family of such enzymes is that of the matrix metalloproteinases (MMPs). To control MMP-mediated ECM breakdown, tissue inhibitors of metalloproteinases (TIMPs) are able to inhibit MMP activity. A disturbed balance of MMPs and TIMPs is found in various pathologic conditions, such as cancer, rheumatoid arthritis, and periodontitis. The role of MMPs in pathology has been extensively described in the literature. The main focus of this review lies in the biological functions of TIMPs and their occurrence in disease, especially in the head and neck area. Their biological functions and their role in diseases like oral cancers and periodontitis, and in the development of cleft palate, will be discussed. Finally, the diagnostic and therapeutical opportunities of TIMPs will be evaluated.

Tissue Inhibitor of Matrix Metalloproteinase-1 Is Prognostic in Head and Neck Squamous Cell Carcinoma: Comparison of the Circulating and Tissue Immunoreactive Protein

PURPOSE

Tissue inhibitors of metalloproteinases (TIMP) are capable of inhibiting the matrix metalloproteinases, but they also possess other biological functions. Little is known about the role of TIMP-1 in the progression and spreading of cancer cells among patients with head and neck squamous cell carcinoma (HNSCC). In this study, the pretreatment serum levels of TIMP-1 or the overexpression of TIMP-1 immunoreactive protein in the primary tumor was correlated to the clinical course in patients with HNSCC.

EXPERIMENTAL DESIGN

The TIMP-1 immunoreactive protein was studied in 74 cases representing HNSCC. The tissue immunoreactive protein was evaluated from paraffin-embedded tumor sections in 68 cases using immunohistologic staining with a specific antibody, and in 68 cases the pretreatment serum levels of TIMP-1 were quantitatively measured by ELISA assay. The results were compared with the clinicopathologic factors of the disease and the patients' outcome.

RESULTS

A positive correlation was found between the size of the primary tumor (T) and the circulating TIMP-1 level (P = 0.021) or the positive immunoreaction of TIMP-1 in tumor (P = 0.039). The 5-year cause-specific survival was significantly lower in patients presenting with a high serum TIMP-1 level than in those with a low level of TIMP-1 (38% versus 64%, P = 0.034). They also had an unfavorable 5-year relapse-free survival rate (37% versus 56%, respectively). Similarly, the expression of TIMP-1 in tumor was prognostic for shortened survival, the 5-year cumulative relapse-free survival being 42% in patients with a TIMP-1-positive tumor versus 75% in cases with a negative tumor (P = 0.035). Tissue TIMP-1 positivity also seemed associated to the cause-specific survival (P = 0.075) and to be connected with later lymph node or hematogenic relapses.

CONCLUSIONS

This study shows for the first time that both circulating and tissue TIMP-1 immunoreactive protein predicts the clinical course and dissemination in HNSCC, suggesting that TIMP-1 might be related to both tumor growth and metastasis in HNSCC.

Expression of matrix metalloproteinase-9 in head and neck squamous cell carcinoma: a potential marker for prognosis

PURPOSE

Previous studies have shown that matrix metalloproteinase-9 (MMP-9) is expressed in malignant head and neck squamous cell carcinoma. The prognostic role of MMP-9 is still unclear. The aim of this study was to investigate the role of MMP-9 immunoreactive protein as a prognostic marker for survival in head and neck squamous cell carcinoma.

EXPERIMENTAL DESIGN

Overexpression of the immunoreactive protein for MMP-9 was evaluated in tissue sections of 74 primary head and neck carcinomas with a monoclonal antibody using a biotin-streptavidin immunohistochemical staining method. The staining results were compared with the clinical data and to the patients' outcome.

RESULTS

Positive immunostaining for MMP-9 was observed in 82% of the head and neck carcinomas, 39% of the cases being extensively positive. MMP-9 protein expression was independent of the stage or the grade of the tumor. The expression of MMP-9 was prognostic for shortened survival, the 5-year cause-specific survival being 45% in MMP-9 positive cases, and 92% in cases negative for MMP-9 (P = 0.013). MMP-9 positivity also correlated to the relapse-free survival (P = 0.019). At the 5-year follow-up, the cumulative relapse-free survival rate was 79% for patients with MMP-9-negative tumor and 42% for the patients with positive immunostaining for MMP-9. High expression of MMP-9 seemed to be linked with more aggressive relapses, appearing in 33% of the cases in local relapses, in 52% of cases with lymph node relapses, and in 60% of the cases with hematogenic relapses.

CONCLUSIONS

This is the first study with a long follow-up showing that the immunoreactive protein of MMP-9 in head and neck carcinoma is associated with shortened relapse-free and cause-specific survival, suggesting that MMP-9 has a role in tumor progression of head and neck carcinomas, as well as in estimation of the prognosis of these diseases.

MMP-9 activation by tumor trypsin-2 enhances in vivo invasion of human tongue carcinoma cells

Various human cancer cells express tumor-associated trypsinogen-2 (TAT-2), which can efficiently activate matrix metalloproteinases (MMPs) in vitro. MMP-2 and MMP-9 are particularly associated with the invasive malignant potential of several tumors. To investigate the role of TAT-2 in tumor invasion, we overexpressed TAT-2 in two malignant human squamous cell carcinoma cell lines of tongue and in non-malignant human papilloma virus transformed gingival keratinocytes. The TAT-2 overexpression significantly increased the levels of active MMP-9 in the most malignant cell line. TAT-2-transfected cells intravasated (invaded blood vessels) up to 60% more efficiently than did the control cells in an in vivo chick embryo chorioallantoic membrane invasion model. This increased intravasation was almost completely abolished by a specific tumor-associated trypsin inhibitor (TATI). These results indicate that TAT-2 has a role in the invasive growth of tumors, either alone or in cascade with gelatinases, especially by generating active MMP-9.