Collagenase-3 expression is associated with advanced local invasion in human squamous cell carcinomas of the larynx

Stage-specific expression analysis ofMMP-2 & MMP-9 in laryngeal carcinoma

Aim of the Study

Both matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) is involved in degradation of extracellular matrix and found to stimulate invasion and metastasis in cancer patients. However, studies on the stage-specific expression of MMPs at different stages of larynx carcinoma are still lacking. In the present study, we compare the expression level of MMP-2 and MMP-9 at different stages of laryngeal carcinoma.

Material and Methods

Tumor tissues samples were taken from larynx cancer patients by deep biopsy during direct laryngoscopy. Gene expression for MMP-2 and MMP-9 was analyzed using RT-PCR.

Results

Significantly high expression of MMP-2 was observed compared to the MMP-9 at stage IV compared to the less advanced stages of the disease.

Conclusion

Present study concluded that the MMP-2 expressed with a greater magnitude as compared to the MMP-9 in advance stages of laryngeal carcinoma.

Molecular mechanisms and clinical management of cancer bone metastasis

As one of the most common metastatic sites of malignancies, bone has a unique microenvironment that allows metastatic tumor cells to grow and flourish. The fenestrated capillaries in the bone, bone matrix, and bone cells, including osteoblasts and osteoclasts, together maintain the homeostasis of the bone microenvironment. In contrast, tumor-derived factors act on bone components, leading to subsequent bone resorption or excessive bone formation. The various pathways involved also provide multiple targets for therapeutic strategies against bone metastases. In this review, we summarize the current understanding of the mechanism of bone metastases. Based on the general process of bone metastases, we specifically highlight the complex crosstalk between tumor cells and the bone microenvironment and the current management of cancer bone metastases.

Septin 9 isoforms promote tumorigenesis in mammary epithelial cells by increasing migration and ECM degradation through metalloproteinase secretion at focal adhesions

The cytoskeletal interacting protein Septin 9 (SEPT9), a member of the septin gene family, has been proposed to have oncogenic functions. It is a known hot spot of retroviral tagging insertion and a fusion partner of both de novo and therapy-induced mixed lineage leukemia (MLL). Of all septins, SEPT9 holds the strongest link to cancer, especially breast cancer. Murine models of breast cancer frequently exhibit Sept9 amplification in the form of double minute chromosomes, and about 20% of human breast cancer display genomic amplification and protein over expression at the SEPT9 locus. Yet, a clear mechanism by which SEPT9 elicits tumor-promoting functions is lacking.

To obtain unbiased insights on molecular signatures of SEPT9 upregulation in breast tumors, we overexpressed several of its isoforms in breast cancer cell lines. Global transcriptomic profiling supports a role of SEPT9 in invasion. Functional studies reveal that SEPT9 upregulation is sufficient to increase degradation of the extracellular matrix, while SEPT9 downregulation inhibits this process. The degradation pattern is peripheral and associated with focal adhesions (FA), where it is coupled with increased expression of matrix metalloproteinases. SEPT9 overexpression induces MMP upregulation in human tumors and in culture models and promotes MMP3 secretion to the media at FAs. Downregulation of SEPT9 or chemical inhibition of septin filament assembly impairs recruitment of MMP3 to FAs. Our results indicate that SEPT9 promotes upregulation and both trafficking and secretion of MMPs near FAs, thus enhancing migration and invasion of breast cancer cells.

Osteoactivin regulates head and neck squamous cell carcinoma invasion by modulating matrix metalloproteases

Nearly 60% of patients with head and neck squamous cell carcinoma (HNSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell migration and invasion, which are in part dependent on extracellular matrix degradation by matrix metalloproteinases. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies, and has been shown to upregulate matrix metalloproteinase (MMP) expression and activity. To determine how OA modulates MMP expression and activity in HNSCC, and to investigate OA effects on cell invasion, we assessed effects of OA treatment on MMP mRNA and protein expression, as well as gelatinase and caseinolytic activity in HNSCC cell lines. We assessed the effects of OA gene silencing on MMP expression, gelatinase and caseinolytic activity, and cell invasion. OA treatment had differential effects on MMP mRNA expression. OA treatment upregulated MMP-10 expression in UMSCC14a (p = 0.0431) and SCC15 (p < 0.0001) cells, but decreased MMP-9 expression in UMSCC14a cells (p = 0.0002). OA gene silencing decreased MMP-10 expression in UMSCC12 cells (p = 0.0001), and MMP-3 (p = 0.0005) and -9 (p = 0.0036) expression in SCC25 cells. In SCC15 and SCC25 cells, OA treatment increased MMP-2 (p = 0.0408) and MMP-9 gelatinase activity (p < 0.0001), respectively. OA depletion decreased MMP-2 (p = 0.0023) and -9 (p < 0.0001) activity in SCC25 cells. OA treatment increased 70 kDa caseinolytic activity in UMSCC12 cells consistent with tissue type plasminogen activator (p = 0.0078). OA depletion decreased invasive capacity of UMSCC12 cells (p < 0.0001). OA's effects on MMP expression in HNSCC are variable, and may promote cancer cell invasion.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

Introduction

Several matrix metalloproteinases (MMPs) are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging.

Objective

To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma.

Methods

K-ras^LSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT) and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors.

Results

In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27), but in none of the non-invasive (0/4) (p=0.001).

Conclusion

MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer.

Overexpression of MMP13 is associated with clinical outcomes and poor prognosis in oral squamous cell carcinoma

Matrix metalloproteinase 13 (MMP13) plays a central role in the MMP activation cascade that enables degradation of the extracellular matrix and basement membranes, and it is identified as a potential driver in oral carcinogenesis. Therefore, this study aims to determine the copy number, mRNA, and protein expression of MMP13 in oral squamous cell carcinoma (OSCC) and to associate these expressions with clinicopathological parameters. Copy number, mRNA, and protein expression analysis of MMP13 were determined using real-time quantitative PCR and immunohistochemistry methods in OSCC samples. The correlations between MMP13 expressions and clinicopathological parameters were evaluated, and the significance of MMP13 as a prognostic factor was determined. Despite discrepancies between gene amplification and mRNA and protein overexpression rates, OSCC cases showed high amplification of MMP13 and overexpression of MMP13 at both mRNA and protein levels. High level of MMP13 protein expression showed a significant correlation with lymph node metastasis (P = 0.011) and tumor staging (P = 0.002). Multivariate Cox regression model analysis revealed that high level of mRNA and protein expression of MMP13 were significantly associated with poor prognosis (P < 0.050). Taken together, these observations indicate that the MMP13 protein overexpression could be considered as a prognostic marker of OSCC.

Increased circulating Lin(-/low) CD33(+) HLA-DR(-) myeloid-derived suppressor cells in hepatocellular carcinoma patients

AIM

Myeloid-derived suppressor cells (MDSC) can be induced or expanded in tumor-bearing mice and cancer patients. The frequency of MDSC denoted here as Lin(-/low) CD33(+) HLA-DR(-) was investigated in hepatocellular carcinoma (HCC) patients. The clinical relevance of MDSC and patients' characteristics were examined. Also, MDSC-related immune regulatory pathways in these patients were discussed.

METHODS

The quantity of MDSC was tested in peripheral blood of patients with HCC (n = 63) and healthy donors (n = 56). The expressions of interferon (IFN)-γ, vascular endothelial growth factor (VEGF), cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-13, nitric oxide synthase (NOS)-2 and arginase (ARG)-1 were analyzed. Co-culturing with anti-CD3/CD28-stimulated T lymphocytes was used to determine the suppressive effect of MDSC on the T lymphocytes.

RESULTS

Patients with treatment-naive HCC had an increased subpopulation of Lin(-/low) CD33(+) HLA-DR(-) cells in the peripheral blood mononuclear cells (PBMC) with characteristics of MDSC and associated to the stage (P = 0.0004). Patients with splenomegaly had a higher frequency of circulating MDSC. Also, COX-2, MMP-13 and VEGF were expressed differently associated with the alteration of MDSC.

CONCLUSION

Our study provides evidence showing an increased population of Lin(-/low) CD33(+) HLA-DR(-) MDSC in the peripheral blood of HCC patients. Our data also suggest that MMP-13 and COX-2 in PBMC may play a new important role companied with MDSC in HCC patients.

Interleukin-11 induces the expression of matrix metalloproteinase 13 in gastric cancer SCH cells partly via the PI3K-AKT and JAK-STAT3 pathways

Interleukin (IL)-11 is expressed in the majority of gastric carcinomas and has been associated with an aggressive phenotype and poor prognosis of gastric adenocarcinoma. Matrix metalloproteinase (MMP)-13 has been detected in numerous invasive malignant tumor types and exhibits a broad spectrum of activities on connective tissue components. In this study, we investigated whether IL-11 affects the expression of MMP-13 in human gastric cancer cells, as well as the underlying mechanism. Using western blot assays, we investigated the effect of recombinant human (rh) IL-11 on the expression of MMP-13 in gastric carcinoma cell lines. Using the PI3K inhibitor wortmannin and RNA interference to target the STAT3 gene, we investigated the effects of PI3K inhibition and/or STAT3 depletion on the expression of the MMP-13 protein. Results showed that IL-11 induced MMP-13 expression in a time- and concentration-dependent manner in SCH cells. IL-11 activated PI3K-AKT and JAK-STAT3 signal transduction. Wortmannin and depletion of STAT3 by means of small interfering RNA (siRNA) synergistically reduced the expression of MMP-13. These findings suggested that IL-11 induces the expression of MMP-13 in gastric cancer SCH cells partly via the PI3K-AKT and JAK-STAT3 pathways.

The transcription factor SPDEF suppresses prostate tumor metastasis

Emerging evidence suggests that the SAM pointed domain containing ETS transcription factor (SPDEF) plays a significant role in tumorigenesis in prostate, breast, colon, and ovarian cancer. However, there are no in vivo studies with respect to the role of SPDEF in tumor metastasis. The present study examined the effects of SPDEF on tumor cell metastasis using prostate tumor cells as a model. Utilizing two experimental metastasis models, we demonstrate that SPDEF inhibits cell migration and invasion in vitro and acts a tumor metastasis suppressor in vivo. Using stable expression of SPDEF in PC3-Luc cells and shRNA-mediated knockdown of SPDEF in LNCaP-Luc cells, we demonstrate for the first time that SPDEF diminished the ability of disseminated tumors cells to survive at secondary sites and establish micrometastases. These effects on tumor metastasis were not a result of the effect of SPDEF on cell growth as SPDEF expression had no effect on cell growth in vitro or subcutaneous tumor xenograft-growth in vivo. Transcriptional analysis of several genes associated with tumor metastasis, invasion, and the epithelial-mesenchymal transition demonstrated that SPDEF expression selectively down-regulated MMP9 and MMP13 in prostate cancer cells. Further analysis indicated that forced MMP9 or MMP13 expression rescued the invasive phenotype in SPDEF expressing PC3 cells in vitro, suggesting that the effects of SPDEF on tumor invasion are mediated, in part, through the suppression of MMP9 and MMP13 expression. These results demonstrate for the first time, in any system, that SPDEF functions as a tumor metastasis suppressor in vivo.

Prognostic significance of matrix metalloproteinase-2, -8, -9, and -13 in oral tongue cancer

BACKGROUND

Oral tongue squamous cell carcinoma (OTSCC) often metastasizes to cervical lymph nodes. Mechanisms of this disease progression are not fully known. We aimed at finding new predictive markers for diagnosis and disease monitoring.

METHODS

Seventy-three consecutive T1N0M0 and T2N0M0 OTSCC patients treated at Helsinki University Central Hospital, Helsinki, Finland, in 1992-2002 were included. Tissue array blocks were prepared from primary tumors and immunostained. Immunoexpression of matrix metalloproteinase (MMP)-2, -8, -9, and -13 was compared with patient characteristics and outcome.

RESULTS

Nuclear expression of MMP-13, but not cytoplasmic expression of MMP-2, -8, and -9, was associated with invasion depth (P = 0.017) and tumor size (P = 0.008). Furthermore, high nuclear MMP-13 expression was predictive of poor outcome (P = 0.042).

CONCLUSION

Our results suggest that especially MMP-13 may be regarded as a prognostic biomarker in OTSCC.

Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes

Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.

Expression of matrix metalloproteinases and their inhibitors in squamous cell carcinoma of the tonsil and their clinical significance

OBJECTIVES

To investigate expressions of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in squamous cell carcinoma of the tonsil and to correlate expression profiles with clinicopathological characteristics.

METHODS

Paraffin blocks were obtained from 45 tonsil squamous cell carcinoma (SCC) patients, who underwent surgery as an initial treatment between 1994 and 2004, and from 20 normal controls. Expressions of MMP-2, MMP-9, MMP-13, TIMP-1, and TIMP-2 were investigated immunohistochemically.

RESULTS

The expressions of MMPs (except MMP-2) and TIMPs were found to be significantly different in tonsil SCC and normal control tissues. Furthermore, MMP-13 expression was found to be correlated with tumor invasion (P=0.05), and the expressions of MMP-9 and TIMP-1 with nodal metastasis (P=0.048, 0.031). No relation was found between MMP or TIMP expression and recurrence. However, MMP-9 expression was found to be significantly associated with 5-year survival in tonsil SCC patients by multivariate analysis (hazard ratio, 3.853; P=0.013).

CONCLUSION

Significant overexpressions of multiple MMPs and TIMPs were found in tonsil SCC tissues. Furthermore, our findings suggest that MMP-9 expression might be a useful prognostic factor.

MMP-13 expression in keratocyst odontogenic tumour associated with NBCCS and sporadic keratocysts

OBJECTIVE

To investigate the matrix metalloproteinase (MMP)-13 expression in associated and non-nevoid basal cell carcinoma syndrome (NBCCS) Odontogenic Keratocysts (OCKs) in order to contribute to a better understanding of the differences in the growth pattern between them.

MATERIALS AND METHODS

Thirty-nine paraffin-embedded blocks of OCKs, 26 sporadic OCKs and 11 NBCCS-associated KCOTs were studied by immunohistochemistry to evaluate MMP-13 expression both in epithelial and stromal layers. A semi-quantitative scale was used to evaluate immunostaining. Obtained data were compared between the two groups, using Fischer's exact test and the chi-square test.

RESULTS

Only 13 of 26 sporadic OCKs showed a positive immunostaining, whilst 11 KCOTs resulted in positive labelling for MMP-13 expression. Moreover, syndromic cysts displayed a more intense and diffuse MMP-13 labelling of the stromal tissue. Instead, in non-syndromic forms, the staining pattern of MMP-13 in stromal tissue was completely absent. Fisher's exact test showed a statistically significant greater prevalence of KCOTs-immunolabelled cysts with respect to sporadic OCKs.

CONCLUSIONS

Results from this study point out that the biological behaviour of these cysts could be related not only to the epithelial layer but also to stromal tissue in that... MMP-13 overexpression in stromal tissue of NBCCS-associated KCOTs could clarify the higher aggressiveness of these cysts.

Phenotypic overlap between MMP-13 and the plasminogen activation system during wound healing in mice

BACKGROUND

Proteolytic degradation of extracellular matrix is a crucial step in the healing of incisional skin wounds. Thus, healing of skin wounds is delayed by either plasminogen-deficiency or by treatment with the broad-spectrum metalloproteinase (MP) inhibitor Galardin alone, while the two perturbations combined completely prevent wound healing. Both urokinase-type plasminogen activator and several matrix metallo proteinases (MMPs), such as MMP-3, -9 and -13, are expressed in the leading-edge keratinocytes of skin wounds, which may account for this phenotypic overlap between these classes of proteases.

METHODOLOGY

To further test that hypothesis we generated Mmp13;Plau and Mmp13;Plg double-deficient mice in a cross between Mmp13- and Plau-deficient mice as well as Mmp13- and Plg-deficient mice. These mice were examined for normal physiology in a large cohort study and in a well-characterized skin wound healing model, in which we made incisional 20 mm-long full-thickness skin wounds.

PRINCIPAL FINDINGS

While mice that are deficient in Mmp13 have a mean healing time indistinguishable to wild-type mice, wound healing in both Plau- and Plg-deficient mice is significantly delayed. Histological analysis of healed wounds revealed a significant increase in keratin 10/14 immunoreactive layers of kerationcytes in the skin surface in Mmp13;Plau double-deficient mice. Furthermore, we observe, by immunohistological analysis, an aberrant angiogenic pattern during wound healing induced by Plau-deficiency, which has not previously been described.

CONCLUSIONS

We demonstrate a phenotypic overlap, defined as an additional delay in wound healing in the double-deficient mice compared to the individual single-deficient mice, between MMP-13 and the plasminogen activation system in the process of wound healing, but not during gestation and in postnatal development. Thus, a dual targeting of uPA and MMP-13 might be a possible future strategy in designing therapies aimed at tissue repair or other pathological processes, such as cancer invasion, where proteolytic degradation is a hallmark.

Matrix metalloproteinase (MMP)-13 regulates mammary tumor-induced osteolysis by activating MMP9 and transforming growth factor-beta signaling at the tumor-bone interface

The tropism of breast cancer cells for bone and their tendency to induce an osteolytic phenotype are a result of interactions between breast cancer cells and stromal cells and are of paramount importance for bone metastasis. However, the underlying molecular mechanisms remain poorly understood. We hypothesize that tumor-stromal interaction alters gene expression in malignant tumor cells and stromal cells creating a unique expression signature that promotes osteolytic breast cancer bone metastasis and that inhibition of such interactions can be developed as targeted therapeutics. Microarray analysis was performed to investigate gene expression profiling at the tumor-bone (TB) interface versus the tumor alone area from syngenic mice injected with three different syngenic mammary tumor cell lines that differ in their metastatic potential. We identified matrix metalloproteinase 13 (MMP13), receptor activator of NF-kappaB ligand (RANKL), and integrins binding sialoprotein to be genes upregulated at the TB interface and validated. To determine the functional role of MMP13 in tumor-induced osteolysis, mice with Cl66 mammary tumors were treated with MMP13 antisense oligonucleotides (MMP13-ASO) or control scrambled oligonucleotides (control-ASO). Knockdown of MMP13 expression at the TB interface leads to significant reduction in bone destruction and in the number of activated osteoclasts at the TB interface. Further analysis to evaluate the mechanism of MMP13-dependent osteolytic bone metastasis revealed that MMP13-ASO treatment decreased active MMP9, RANKL levels, and transforming growth factor-beta signaling at the TB interface. Together, our data indicate that upregulation of MMP13 at the TB interface is important in tumor-induced osteolysis and suggest that MMP13 is a potential therapeutic target for breast cancer bone metastasis.

Matrix metalloproteinase (MMP)-13 regulates mammary tumor-induced osteolysis by activating MMP9 and transforming growth factor-beta signaling at the tumor-bone interface

The tropism of breast cancer cells for bone and their tendency to induce an osteolytic phenotype are a result of interactions between breast cancer cells and stromal cells and are of paramount importance for bone metastasis. However, the underlying molecular mechanisms remain poorly understood. We hypothesize that tumor-stromal interaction alters gene expression in malignant tumor cells and stromal cells creating a unique expression signature that promotes osteolytic breast cancer bone metastasis and that inhibition of such interactions can be developed as targeted therapeutics. Microarray analysis was performed to investigate gene expression profiling at the tumor-bone (TB) interface versus the tumor alone area from syngenic mice injected with three different syngenic mammary tumor cell lines that differ in their metastatic potential. We identified matrix metalloproteinase 13 (MMP13), receptor activator of NF-kappaB ligand (RANKL), and integrins binding sialoprotein to be genes upregulated at the TB interface and validated. To determine the functional role of MMP13 in tumor-induced osteolysis, mice with Cl66 mammary tumors were treated with MMP13 antisense oligonucleotides (MMP13-ASO) or control scrambled oligonucleotides (control-ASO). Knockdown of MMP13 expression at the TB interface leads to significant reduction in bone destruction and in the number of activated osteoclasts at the TB interface. Further analysis to evaluate the mechanism of MMP13-dependent osteolytic bone metastasis revealed that MMP13-ASO treatment decreased active MMP9, RANKL levels, and transforming growth factor-beta signaling at the TB interface. Together, our data indicate that upregulation of MMP13 at the TB interface is important in tumor-induced osteolysis and suggest that MMP13 is a potential therapeutic target for breast cancer bone metastasis.

The usefulness of new serum tumor markers in head and neck squamous cell carcinoma

Objective: To determine the usefulness of specific and reliable serum biomarkers to predict cervical lymph node metastasis.

Methods: A cross-sectional study of cases and controls. Thirty-nine serum samples of head and neck squamous cell carcinoma were collected from patients during neoplasm resection. Another 10 serum samples were collected from healthy individuals as a control group. Selected serum biomarkers were E-cadherin, MMP-2, MMP-9, active MMP-13, and p53 autoantibodies.

Results: We found a correlation between active MMP-13 (>685 pg/mL; ROC curve analysis 95% CI for sensitivity 79.6-99.3; specificity 49.2-95.1; positive predictive value 65-100; and negative predictive value 36-100) as well as the presence of p53 autoantibodies and lymph node metastasis. Multimarker analysis using MMP-13 and p53 autoantibodies together provided better sensitivity (76%) and specificity (100%).

Conclusions: The combined determination of active MMP-13 and p53 autoantibodies could improve diagnosis of lymphatic metastasis in head and neck squamous cell carcinoma and aid therapeutic decision making.

Influence of persistent canine distemper virus infection on expression of RECK, matrix-metalloproteinases and their inhibitors in a canine macrophage/monocytic tumour cell line (DH82)

A morbillivirus infection of tumour cells is known to exert oncolytic activity, but the mechanism of this inhibitory action has not been well defined. Matrix metalloproteinases (MMPs) are important enzymes degrading the extracellular matrix and are often upregulated in malignant neoplasms. Recent studies have demonstrated that RECK may potently suppress MMP-2 and -9 activity, thus inhibiting angiogenesis and metastasis. In this study, real time quantitative polymerase chain reaction (RT-qPCR) was used to determine the effect of persistent infection with canine distemper virus (CDV) infection on the expression of MMPs and their inhibitors (TIMPS) in a canine macrophage/monocytic tumour cell line (DH82). The activity of proMMP-2 and proMMP-9 was also verified zymographically. Following CDV infection, MMP-2, TIMP-1 and TIMP-2 were down-regulated, while RECK was upregulated. These findings suggest that CDV infection restores RECK expression in tumour cells and may interfere with the intracellular processing of MMPs and TIMPs, thus possibly influencing tumour cell behaviour beneficially for the host. However, this needs to be verified in in vivo studies.

Is collagenase-3 (MMP-13) expression in chondrosarcoma of the jaws a true marker for tumor aggressiveness?

BACKGROUND

Matrix metalloproteinases (MMPs) play an important role in the modeling and remodeling of the extracellular matrix in both physiologic and pathologic states and thus plays an important role in tumor progression. Human collagenase-3 (MMP-13) is a member of matrix metalloproteinase family of enzymes that was originally identified in breast carcinomas and subsequently detected during fetal ossification and in arthritic processes.

AIM

The present study was designed to investigate the expression MMP-13 and to correlate its expression with clinicopathological parameters in chondrosarcoma of the jaws.

METHODS

Archival tumor tissues from 11 patients with chondrosarcoma of the jaws were analyzed by immunohistochemistry for the expression of MMP-13. Clinical information was obtained through the computerized retrospective database from the tumor registry between 1998 to 2006.

RESULTS

Eight of 11 cases (72.8 %) of chondrosarcomas showed a positive reaction for MMP-13, whereas two cases of normal cartilage were negative for this collagenase. As regard the clinicopathological parameters, there was no correlation between MMP-13 expression and sex, age and tumor site. While, there were significant associations between MMP-13 expression and both of mitotic counts and necrosis. On the other hand, there was a significant difference between low and high grade tumors (P < 0.05) regarding MMP-13 expression. Also, there was no significant correlation between MMP-13 expression in primary lesions and their local recurrence.

CONCLUSION

MMP-13 is expressed in the majority of chondrosarcoma of the jaws. It is also noteworthy that the expression of MMP-13 may be related to tumor biological aggressiveness and used to aid in predicting patient's poor prognosis.

Role of metalloproteins in the clinical management of head and neck squamous cell carcinoma

Metalloproteins are a group of catalytic proteins, which play significant roles in cell cycle and death. Matrix metalloproteinases (MMPs) are a family of endopeptidases that are capable of digesting extracellular matrix components. They have been implicated in carcinogenesis and recent developments have been made to use MMPs clinically to predict outcomes. In the future, selective inhibition of these proteins and their regulatory pathways may prove useful in anticancer therapeutics. We present a review article on the clinical applications of metalloproteins in head and neck squamous cell carcinoma (HNSCC). Metalopanstimulin is highlighted as a putative metalloprotein of interest for those treating HNSCC. Expression of particular metalloproteins has correlation with lymph node metastasis, tumor invasiveness, and overall prognosis in HNSCC.

Collagenase and surgical disease

Collagen types I, II, and III are the most abundant extracellular matrix (ECM) proteins. Collagenase is a member of the matrix metalloproteinase (MMP) family of enzymes, and is the principal enzyme involved with collagen degradation. Cellular-ECM interactions are vitally important to tissue structure and function. In this review, we summarize recent work that highlights the role of collagenase in ECM remodeling and repair, and further report that alterations of collagenase expression, function, and/or regulation are found in many diverse disease states, including aortic aneurysms, tumor invasiveness and their metastases, and hernias. Collagenase is intimately involved in many surgical diseases, and represents a potential target for therapy.

Association between high collagenase-3 expression levels and poor prognosis in patients with head and neck cancer

BACKGROUND

Squamous cell carcinoma of the head and neck (HNSCC) is a common cancer type. The ability for curative treatment with surgery and radiotherapy (RT) is usually highly dependent on tumor stage at the time of diagnosis.

METHODS

The purpose of this study was to determine whether the expression of a cancer-specific proteinase, collagenase-3 (matrix metalloproteinase-13 [MMP-13]), is associated with survival parameters in patients with HNSCC. We studied MMP-13 expression in tumors of 81 patients with stage I-IV HNSCC treated with surgery alone or in combination with radiotherapy.

RESULTS

We found a subgroup of patients with high MMP-13 expression level in their tumors (>/=90% MMP-13-positive tumor cells) associated with unfavorable prognosis (median overall survival [OS], 11.8 vs 19.6 months, p = .032). In addition, the median disease-specific survival (DSS) time was markedly reduced in this subgroup (13.8 months vs 40.7 months, p = .062). When the subgroup of patients treated with a curative intent was studied, the same association was found in OS (13.8 vs 24.6 months, p = .023) and DSS (p = .004). In addition, there was a trend for association between >/=90% MMP-13 positivity and a recurrent tumor (p = .078) in curatively treated patients.

CONCLUSIONS

The short survival time associated with high MMP-13 expression levels could not be predicted by tumor size or local lymph node invasion. These results show that a high MMP-13 expression level is associated with aggressiveness of HNSCC and may have prognostic value in patient evaluation.

Primary hyperparathyroidism and malignancy: "studies by nature"

The American Food and Drug Administration approval of parathyroid hormone (PTH) administration for osteoporosis as well as the possibility for its future therapeutic applications requires an examination of the suggested association between PTH and cancer, particularly osteosarcomas. The objective was to evaluate such a connection by collecting observational data from two groups of patients, designated as "studies by nature". Cohort 1: Medical records of all patients with primary hyperparathyroidism that were treated in a referral center during a 12-year period were retrospectively reviewed for malignancy before, at the time or after diagnosis. Cohort 2: Records of patients with osteosarcomas that were treated in referral centers during 15 years were retrospectively reviewed for hyperparathyroidism, as indicated by history or laboratory results. There were 582 patients with primary hyperparathyroidism. While 56 (9.6%) had malignancy, 47 (8%) developed cancer after diagnosis with hyperparathyroidism during 6.1 years of documentation. This rate did not exceed the incidence of developing cancer among the general population. Although thyroid cancer was about 4 times the incidence in the general population, this may be attributed to a high level of detection while work-up, treating and following the parathyroid disease. None had osteosarcoma. None of the 126 patients with osteosarcoma had documentation of primary hyperparathyroidism or had biochemical evidence of hyperparathyroidism. No obvious association was found between primary hyperparathyroidism and cancer. Similarly, there was no demonstrable relationship between osteosarcomas and hyperthyroidism biochemical stigmata. Since PTH may contribute to tumor invasiveness, screening for existing neoplasms, especially prostate and breast, before PTH treatment may be of importance.

Activation of Smad signaling enhances collagenase-3 (MMP-13) expression and invasion of head and neck squamous carcinoma cells

Squamous cell carcinoma (SCC) cells of the head and neck specifically express collagenase-3 (matrix metalloproteinase-13 (MMP-13)), the expression of which correlates with their invasion capacity. Transforming growth factor-beta (TGF-beta) enhances MMP-13 and collagenase-1 (MMP-1) expression and invasion of SCC cells via p38 mitogen-activated protein kinase. Here, we have examined the role of Smad signaling in regulating MMP-13 expression and in invasion of head and neck SCC cells. Treatment with TGF-beta resulted in activation of Smad2 and Smad3 in SCC cells, but had no effect on their proliferation or viability. Basal activation of Smad3 and p38 was noted in SCC cells without exogenous TGF-beta stimulation, and adenoviral delivery of Smad7 and dominant-negative Smad3 inhibited p38 activation in these cells. Adenoviral overexpression of Smad3 augmented the upregulatory effect of TGF-beta on MMP-13 expression by SCC cells. Disruption of Smad signaling by adenoviral expression of kinase-defective TGF-beta type I receptor (activin-receptor-like kinase-5), Smad7, and dominant-negative Smad3 potently suppressed the basal and TGF-beta-induced expression of MMP-13 and MMP-1 in SCC cells, and inhibited their basal and TGF-beta-induced invasion through Matrigel and type I collagen. Adenoviral overexpression of Smad7 in cutaneous and oral SCC cells significantly inhibited their implantation in skin of SCID mice and growth of xenografts in vivo, as compared to LacZ adenovirus-transduced control cells. Together, these results show that Smad signaling plays an important role in promoting the invasive phenotype of human head and neck SCC cells by upregulating their collagenase expression.

Collagenase-3 (MMP-13) expression in cutaneous malignant melanoma

BACKGROUND

Matrix metalloproteases (MMPs), enzymes with the ability to degrade the extracellular matrix, play an important role in tissue invasion by cutaneous malignant melanoma (CMM). One specific MMP, collagenase-3 (MMP-13), is thought to have a key function in the activation of MMP.

AIMS

To evaluate the expression of MMP-13 in CMM and assess its possible relationship to clinical and pathological parameters.

METHODS

MMP-13 expression was analyzed in 51 paraffin-embedded tumor samples from patients with invasive CMM, ten samples from in situ melanomas, and in eight samples from benign lesions (three dermal melanocytic nevi, three compound melanocytic nevi and two atypical melanocytic nevi) using immunohistochemical techniques. The median follow-up period in patients with invasive CMM was 50 months.

RESULTS

Benign lesions were consistently negative for MMP-13, whereas three of the ten in situ melanomas (30%) and 23 of the 51 invasive CMMs (45%) showed positive immunostaining for MMP-13. The percentage of MMP-13-positive tumors correlated significantly and positively with the mitotic index (p=0.002) in invasive CMM. However, our results did not show any significant association between tumoral MMP-13 expression and relapse-free survival in patients with invasive CMM.

CONCLUSIONS

MMP-13 appears to be a factor associated with tumor aggressiveness in CMM. It seems to eliminate an important barrier not only against tumoral invasion but also against proliferation.

Confirmation of a linkage between H-Ras and MMP-13 expression as well as MMP-9 by chemical genomic approach

As farnesylation of the Ras protein by farnesyl transferase is a critical step for the Ras functional activity, the farnesyl transferase inhibitor could affect H-Ras functions and the inhibitors such as arteminolide, SCH66336 and LB42908 completely inhibited Ras-farnesylation. However, they did not induce apoptosis of H-Ras-transformed cells with concentration for blocking H-Ras farnesylation. To determine the antitumor effects of the inhibitors, it was analyzed through the expression profile of genes, regulated by activated H-Ras or FTIs by using cDNA microarray. On the basis of the results, the relationship between H-Ras and MMPs expression was confirmed by RT-PCR, Western bolt, zymographic analysis and angiogenesis assay. Our results suggested that activation of MMP-13 as well as MMP-9 induced by H-Ras is involved in angiogenesis and with farnesyl transferase inhibitors, in part, exerts their anticancer effects. We confirmed that MMP-13 is a critical H-Ras target gene through chemical genomic approaches with farnesyl transferase inhibitors.

Collagenases in cancer

Three mammalian collagenases (MMP-1, MMP-8, and MMP-13) belong to family of matrix metalloproteinases and are the principal secreted endopeptidases capable of cleaving collagenous extracellular matrix. In addition to fibrillar collagens, collagenases can cleave several other matrix and non-matrix proteins including growth factors, and this way regulate cell growth and survival. Collagenases are important proteolytic tools for extracellular matrix remodeling during organ development and tissue regeneration, but they also apparently play important roles in many pathological situations and tumor progression and metastasis. Because of their potentially destructive characteristics the expression and activity of collagenases are strictly controlled. Synthesis of collagenases is regulated by extracellular signals via cellular signal transduction pathways at transcriptional and post-transcriptional level. Collagenases are synthesized as inactive pro-forms, and once activated, their activity is inhibited by specific tissue inhibitors of metalloproteinases, TIMPs, as well as by non-specific proteinase inhibitors. In this review we discuss the current view on the role of collagenases in tumor growth, invasion, and metastasis, as a basis for their feasibility in diagnosis and prognostication, as well as therapeutic targets in cancer patients.

Piperine is a potent inhibitor of nuclear factor-kappaB (NF-kappaB), c-Fos, CREB, ATF-2 and proinflammatory cytokine gene expression in B16F-10 melanoma cells

Immune regulation, induction of various inflammatory and growth regulatory genes such as IL-1beta, IL-6, TNF-alpha and GM-CSF require activation of transcription factors such as nuclear factor-kappaB (NF-kappaB), activated transcription factor (ATF-2), c-Fos and cAMP response element-binding protein (CREB). Untreated B16F-10 cells produce very high amount of proinflammatory cytokines such as IL-1beta, IL-6, TNF-alpha and GM-CSF. Piperine treatment significantly reduced the above proinflammatory cytokines. We also found that piperine could reduce the expression of IL-1beta, IL-6, TNF-alpha, GM-CSF and IL-12p40 genes. Piperine at a concentration of 2.5, 5 and 10 microg/ml inhibited the collagen matrix invasion of B16F-10 melanoma cells in a dose-dependent manner. Piperine could inhibit the matrix metalloproteinase production which was demonstrated by zymographic analysis. We found that the nuclear translocation of p65, p50, c-Rel subunits of NF-kappaB and other transcription factors such as ATF-2, c-Fos and CREB were inhibited by the treatment of piperine.

Overexpression of MMP-2 in laryngeal squamous cell carcinoma: a potential indicator for poor prognosis

OBJECTIVES

To investigate the expression and clinical significance of gelatinases (MMP-2 and MMP-9) in patients with laryngeal squamous cell carcinoma (LSCC).

STUDY DESIGN AND SETTING

In a retrospective study of 72 consecutive patients with LSCC hospitalized in a single cancer center, immunohistochemistry was used to examine the expression of MMP-2 and MMP-9 in surgical samples. The results were compared to clinicopathological features and prognosis.

RESULTS

The positive expression of MMP-2 and MMP-9 in patients with LSCC was 50% (36/72) and 73.6% (53/72), respectively. According to the expression scale, there were 36 patients of -, 26 patients of +, 7 patients of ++, and 3 patients of +++ expression of MMP-2; 19 patients of -, 26 patients of +, 16 patients of ++, and 11 patients of +++ expression of MMP-9. There was no significant relationship found between the expression of MMP-2 or MMP-9 and clinicopathological features of LSCC, such as histological grade, primary site, T stage, N stage, and clinical stage. The 5-year overall survival (OS) and disease-free survival (DFS) rate calculated by Kaplan-Meier method in patients with negative and positive expression of MMP-9 and MMP-2 was 73.68%, 50.94%, 73.68%, and 49.06% in MMP-9 and 72.22%, 41.67%, 72.22%, and 38.89% in MMP-2, respectively. Significant 5-year survival difference was found between patients with negative and positive expression of MMP-2 (log rank = 6.74, P = 0.0094). There was significant lower survival rate in patients with higher positive expression of MMP-2 (log rank = 11.77, P = 0.0028). In glottic laryngeal cancer, positive expression of MMP-2 could predict poor survival and was more likely to present primary recurrence.

CONCLUSION

The expression of MMP-2 could be used as a potential predictor for poor prognosis in patients with LSCC.

Expression of Matrix Metalloproteinases in Supraglottic Carcinoma and Its Clinical Implication for Estimating Lymph Node Metastases

OBJECTIVE

Twenty to 30% of clinically node-negative patients with squamous cell carcinoma (SCC) of supraglottic larynx were pathologically confirmed with occult lymph node metastasis after operation. Therefore, preoperative judgment on the neck node metastasis should be very important for making an appropriate surgical plan. The purpose of this study is to explore the role of matrix metalloprotineases (MMPs) in the metastatic potential of supraglottic carcinoma in this regard.

STUDY DESIGN

Examination of MMPs expression in supraglottic carcinoma and establishment of the mathematic model for diagnosis of occult lymph node metastases in a prospective manner.

METHODS

Thirty-two patients with supraglottic SCC underwent supraglottic horizontal partial laryngectomy and neck dissection, and the samples of primary cancer and the corresponding adjacent non-neoplastic tissues were evaluated for both mRNA and protein expression of MMP-1, MMP-2, MMP-7, MMP-8, MMP-9, and MMP-10 using reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. In addition, cervical lymph nodes were examined by routine histopathology to determine whether there was any evidences of node metastasis. RT-PCR and immunohistochemical data were analyzed by multivariate logistic regression, and then two mathematical models were established according to the multivariate logistic regression analysis.

RESULTS

Among the six kinds of MMPs, both mRNA and protein expression of MMP-2, MMP-7, and MMP-9 were found up-regulated in more than 63% of the tumor tissues as compared with the adjacent non-neoplastic tissues, and this was significantly correlated with lymph node metastasis (all P < .05). Twenty patients, including seven cases with N0, were pathologically confirmed as having cervical lymph node metastasis. Using RT-PCR and immunohistochemical data of MMP-2, MMP-7, and MMP-9, two mathematic models were tested, and their diagnostic efficiencies for lymph node metastasis were 84% and 88%, respectively.

CONCLUSION

Expressions of MMP-2, MMP-7, and MMP-9 are up-regulated in supraglottic carcinoma tissues, suggesting that MMPs may be useful in the detection of occult lymph node metastasis but that more research is needed.

Extracellular S100A4(mts1) stimulates invasive growth of mouse endothelial cells and modulates MMP-13 matrix metalloproteinase activity

S100A4(mts1) protein expression has been strongly associated with metastatic tumor progression. It has been suggested as a prognostic marker for a number of human cancers. It is proposed that extracellular S100A4 accelerates cancer progression by stimulating the motility of endothelial cells, thereby promoting angiogenesis. Here we show that in 3D culture mouse endothelial cells (SVEC 4-10) respond to recombinant S100A4 by stimulating invasive growth of capillary-like structures. The outgrowth is not dependent on the stimulation of cell proliferation, but rather correlates with the transcriptional modulation of genes involved in the proteolytic degradation of extracellular matrix (ECM). Treatment of SVEC 4-10 with the S100A4 protein leads to the transcriptional activation of collagenase 3 (MMP-13) mRNA followed by subsequent release of the protein from the cells. Beta-casein zymography demonstrates enhancement of proteolytic activity associated with MMP-13. This observation indicates that extracellular S100A4 stimulates the production of ECM degrading enzymes from endothelial cells, thereby stimulating the remodeling of ECM. This could explain the angiogenic and metastasis-stimulating activity of S100A4(mts1).

Targeted inhibition of human collagenase-3 (MMP-13) expression inhibits squamous cell carcinoma growth in vivo

Squamous cell carcinomas (SCCs) of the head and neck are characterized by a high tendency for local invasion and metastasis to lymph nodes. Collagenase-3 (MMP-13) is specifically expressed by tumor cells in SCCs of the head and neck and its expression correlates with their invasion capacity. To specifically examine the role of MMP-13 in the growth and invasion of SCC, we constructed a hammerhead ribozyme targeted against human MMP-13 mRNA. The anti-MMP-13 ribozyme effectively cleaved MMP-13 transcripts in vitro. Adenoviral delivery of the anti-MMP-13 ribozyme to cutaneous metastatic SCC cells in culture resulted in potent and specific inhibition of the production of proMMP-13 and markedly suppressed invasion of SCC cells through Matrigel. In addition, adenoviral delivery of anti-MMP-13 ribozyme promoted apoptosis in SCC cells within 72 h. Intratumoral injection of anti-MMP-13 ribozyme coding adenovirus into human SCC xenografts established in SCID mice potently suppressed tumor growth, inhibited MMP-13 expression and gelatinolytic activity and reduced the number of proliferating cells within the tumors. These results provide evidence for an important role for MMP-13 in SCC growth and invasion and identify MMP-13 as a promising target for ribozyme-based therapy of SCC in vivo.

Functional significance of metastasis-inducing S100A4(Mts1) in tumor-stroma interplay

Causal implication of S100A4 in inducing metastases was convincingly shown previously. However, the mechanisms that associate S100A4 with tumor progression are not well understood. S100A4 protein, as a typical member of the S100 family, exhibits dual, intracellular and extracellular, functions. This work is focused on the extracellular function of S100A4, in particular its involvement in tumor-stroma interplay in VMR (mouse adenocarcinoma cell line) tumor cells, which exhibit stroma-dependent metastatic phenotype. We demonstrated the reciprocal influence of tumor and stroma cells where tumor cells stimulate S100A4 secretion from fibroblasts in culture. In turn, extracellular S100A4 modifies the cytoskeleton and focal adhesions and triggers several other events in tumor cells. We found stabilization of the tumor suppressor protein p53 and modulation of its function. In particular, extracellular S100A4 down-regulates the pro-apoptotic bax and the angiogenesis inhibitor thrombospondin-1 genes. For the first time, we demonstrate here that the S100A4 protein added to the extracellular space strongly stimulates proteolytic activity of VMR cells. This activity most probably is associated with matrix metalloproteinases and, in particular, with matrix metalloproteinase-13. Finally, the application of the recombinant S100A4 protein confers stroma-independent metastatic phenotype on VMR tumor cells. In conclusion, our results indicate that metastasis-inducing S100A4 protein plays a pivotal role in the tumor-stroma environment. S100A4 released either by tumor or stroma cells triggers pro-metastatic cascades in tumor cells.

Differential expression of matrilysin-1 (MMP-7), 92 kD gelatinase (MMP-9), and metalloelastase (MMP-12) in oral verrucous and squamous cell cancer

Squamous cell carcinoma (SCC) of the oral cavity is a highly invasive tumour of stratified squamous epithelium that spreads through degradation of the basement membrane (BM) and extracellular matrix (ECM). There are currently no reliable tissue or serum markers to predict whether the tumour has metastasized at the time of diagnosis. Verrucous carcinoma (VC) of the oral cavity is a rare low-grade variant of oral SCC that penetrates into the subepithelial connective tissue. Many matrix metalloproteinases (MMPs), such as MMP-1, -2, -7, -9, -13, and -14, as well as integrin receptors have been implicated in cancer invasion. Integrin alphavbeta6 is induced in SCC and appears to be involved in up-regulation of MMP-9 expression by oral keratinocytes and promotion of their migration. The aim of this study was to investigate whether the pattern of MMP expression or that of alphavbeta6 integrin contributes to the differences in the biological behaviour of oral SCC and VC. The results show that the less aggressive nature of oral VC may be connected to its MMP expression profile. Typically, VCs were devoid of epithelial MMP-3, -7, -9, -12 and -13 expression, compared with SCCs. MMP-19 was expressed by epithelial keratinocytes in hyperproliferative areas of verrucous hyperplasia, VC, and SCC, but was absent in the invasive cancer cell nests of SCC. MMP-26 was expressed by hyperproliferative keratinocytes in VC as well as by invasive cancer cells in SCCs. MMP-10 was expressed widely in the epithelium of all SCC specimens. alphavbeta6 integrin expression was also detected in some cases of epithelial hyperplasia but was significantly more abundant in cancers at the invasive front. The absence of MMP-7, -9 and -12 from epithelial cells may serve as a good prognostic marker of non-invasive oral carcinoma. Blocking the activity of invasion-specific MMPs or alphavbeta6 integrin might offer novel therapeutic modalities in early-stage oral carcinoma.

Identification and differential expression of human collagenase-3 mRNA species derived from internal deletion, alternative splicing, and different polyadenylation and transcription initiation sites

OBJECTIVE

Collagenase-3 is a metalloprotease that plays a role in tissue remodeling and pathological processes including arthritis. The human gene is transcribed into major (3.0 and 2.5 kb) and minor (2.2/2.0 kb) transcripts, as seen in Northern blot assays. We investigated the possibility that other transcripts, not detectable by Northern blot, were synthesized as either coding or regulatory RNAs that would modulate collagenase-3 expression and function/activity.

DESIGN

We screened a cDNA library and total RNA from human chondrocytes by plaque hybridization and RT-PCR, and expressed the transcripts in a cellular environment. The levels of expression of each transcript in normal and osteoarthritic joint cells and cartilage were monitored by RT-PCR.

RESULTS

We identified five different collagenase-3 RNA species derived from alternative polyadenylation sites (COL3-APS), internal deletion (COL3-DEL), alternative splicing (COL3-9B/COL3-9B-2), and different transcription initiation site (COL3-ATS and COL3-ATS-INT). Each transcript could be translated in a cellular environment. Interestingly, the proteins translated from the COL3-DEL and COL3-9B-2 transcripts had a modified hemopexin-like domain, suggesting altered collagenolytic activities. The transcript types COL3-APS, COL3-9B-2, and COL3-ATS were up-regulated in the osteoarthritic samples and expressed in the chondrosarcoma cell line SW1353.

CONCLUSION

Our data show that the human collagenase-3 gene is subjected to different levels of regulation and constitutes a more complex system than was originally thought.

Prognostic value of MMP-2, -9 and TIMP-1,-2 immunoreactive protein at the invasive front in advanced head and neck squamous cell carcinomas

In head and neck cancer as well as in other carcinomas, tumor expansion and spread to distant sites require the secretion of destructive enzymes that degrade the extracellular matrix. A variety of proteases contribute to matrix destruction. Characteristics of the invasive tumor front may reflect tumor prognosis better than do other parts of the tumor. Therefore, it was the aim of the present study to (i) compare central and peripheral tumor zones for differences in the expression of matrix-metalloproteinases (MMP) -2 and -9 and their naturally occurring inhibitors (tissue inhibitor of matrix-metalloproteinases (TIMP) -1 and -2), (ii) examine the morphological potential of malignancy, and (iii) correlate these findings with clinicopathological parameters. The study population consisted of 106 surgical specimens of advanced head and neck squamous cell carcinomas. The invasive front was graded for malignancy, and immunohistochemical staining with MMP-2, MMP-9, TIMP-1 and TIMP-2 antibodies was performed. Both MMP-2 and MMP-9 were found to be significantly overexpressed at the tumor front. The MMP-2-positive invasive front exhibited diminished overall survival times. In multivariate analysis, MMP-2 expression retained its correlation with overall survival in addition to nodal status and total malignancy score. Expression of TIMP-2 correlated with local tumor invasion. We conclude that the expression of MMP-2 at the invasive front is a marker of poor survival and appears to be associated with early recurrence in initially lymph node-negative patients.

Imidazole ring-opened DNA purines and their biological significance

Fragmentation of purine imidazole ring and production of formamidopyrimidines in deoxynucleosides (Fapy lesions) occurs upon DNA oxidation as well as upon spontaneous or alkali-triggered rearrangement of certain alkylated bases. Many chemotherapeutic agents such as cyclophosphamide or thiotepa produce such lesions in DNA. Unsubstituted FapyA and FapyG, formed upon DNA oxidation cause moderate inhibition of DNA synthesis, which is DNA polymerase and sequence dependent. Fapy-7MeG, a methylated counterpart of FapyG-, a efficiently inhibits DNA replication in vitro and in E.coli, however its mutagenic potency is low. This is probably due to preferential incorporation of cytosine opposite Fapy-7MeG and preferential extension of Fapy-7MeG:C pair. In contrast, FapyA and Fapy-7MeA possess miscoding potential. Both lesions in SOS induced E.coli preferentially mispair with cytosine giving rise to A-->G transitions. Fapy lesions substituted with longer chain alkyl groups also show simult aneous lethal and mutagenic properties. Fapy lesions are actively eliminated from DNA by repair glycosylases specific for oxidized purines and pyrimidines both in bacteria and eukaryotic cells. Bacterial enzymes include E.coli formamidopyrimidine-DNA-glycosylase (Fpg protein), endonuclease III (Nth protein) and endonuclease VIII (Nei protein).

Roles of matrix metalloproteinases in tumor metastasis and angiogenesis

Matrix metalloproteinases (MMPs), zinc dependent proteolytic enzymes, cleave extracellular matrix (ECM: collagen, laminin, firbronectin, etc) as well as non-matrix substrates (growth factors, cell surface receptors, etc). The deregulation of MMPs is involved in many diseases, such as tumor metastasis, rheumatoid arthritis, and periodontal disease. Metastasis is the major cause of death among cancer patients. In this review, we will focus on the roles of MMPs in tumor metastasis. The process of metastasis involves a cascade of linked, sequential steps that involve multiple host-tumor interactions. Specifically, MMPs are involved in many steps of tumor metastasis. These include tumor invasion, migration, host immune escape, extravasation, angiogenesis, and tumor growth. Therefore, without MMPs, the tumor cell cannot perform successful metastasis. The activities of MMPs are tightly regulated at the gene transcription levels, zymogen activation by proteolysis, and inhibition of active forms by endogenous inhibitors, tissue inhibitor of metalloproteinase (TIMP), and RECK. The detailed regulations of MMPs are described in this review.

A critical evaluation of DNA adducts as biological markers for human exposure to polycyclic aromatic compounds

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention or chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria: i. adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined. iii. sources of interand intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAHexposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with nonexposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intraindividual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurements may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurements as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

Activity of matrix metalloproteinases-2 and -9 in advanced laryngeal cancer

OBJECTIVES

Matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) are proteolytic enzymes that digest collagen type IV and other components of the basement membrane. They play a key role in local invasion and the formation of distant metastases by malignant tumors. The aim of this study was to evaluate the activity of MMP-2 and MMP-9 in stage III and IV laryngeal cancers.

STUDY DESIGN

In the study we used specimens of laryngeal cancer and surrounding normal mucosa obtained from 23 patients undergoing surgical treatment as a primary therapy. After extraction of MMP-2 and MMP-9 from tissue samples, their activity was assessed with zymography.

RESULTS

Greater activity of MMP-2 and MMP-9 and a higher active/latent MMP-2 ratio were found in cancer compared with normal mucosa. Moreover, N2 tumors revealed greater activity of MMP-2 in comparison with N1 and N0 tumors.

CONCLUSIONS

Results of the study indicate that both MMP-2 and MMP-9 may be involved in the expansion of laryngeal cancer. MMP-2 may also play an important role in the lymphatic spread of some laryngeal tumors.

[Expression and clinical significance of collagenase-3 (MMP-13) in gastric cancer]

BACKGROUND

MMP-13 (collagenase-3) is a metalloproteinase with potent degradative activity against a variety of elements of the extracellular matrix. Its expression has been described in some human carcinomas, where it seems to play a role in tumor progression and metastasis. The objective of this study was to investigate the expression and clinical significance of MMP-13 in gastric carcinomas.

PATIENTS AND METHOD

MMP-13 expression was analyzed by immunohistochemistry in resected specimens from 44 patients with gastric adenocarcinoma. The mean ( standard error) follow-up period was 21.4 3.2 months.

RESULTS

A total of 14 gastric carcinomas (31.8%) showed positive immunostaining for MMP-13. The percentage of MMP-13-positive tumors was significantly (p = 0.009) higher in stage IV carcinomas (69.2%) than in lower stages (I: 22.2%; II: 12.5%; and III: 14.3%), as well as in nonresectable tumors (R1 and R2) (61.5%) than in resectable carcinomas (R0) (19.4%) (p = 0.017). Likewise, MMP-13 tumor expression was significantly associated with shortened overall survival in both the entire group of patients (p = 0.0006) and in the subgroup of patients with resectable tumors (p = 0.018).

CONCLUSIONS

Our results suggest that, in patients harboring gastric adenocarcinoma, MMP-13 tumor expression is associated with higher tumor aggressiveness and a poor prognosis.

Molecular analysis of surgical margins in head and neck squamous cell carcinoma patients

OBJECTIVES/HYPOTHESIS

Molecular analysis of surgical margins is playing an increasingly important role in establishing surgical margins. Most markers lack the sensitivity and ease of applicability for effective clinical use. To date, the proto-oncogene eIF4E (4E) is elevated in 100% of head and neck squamous cell carcinoma tumors and is of prognostic value in predicting recurrence. In a retrospective study, 4E overexpression in the margins appeared to be a more sensitive predictor of recurrence when compared with p53. The goal was to confirm this finding in a prospective study and also to compare the expression of matrix metalloproteinase-9 (MMP-9) to 4E expression in tumors and margins. Other objectives were to determine which of these markers have prognostic significance in predicting recurrence and elucidate whether there is any additional benefit to analysis of surgical margins with a combination of the three molecular markers.

STUDY DESIGN

A prospective study was performed on all patients who consecutively underwent primary surgical resection between 1998 and 1999 for head and neck squamous cell carcinoma. Patient and tumor characteristics were reviewed, and time to recurrence was noted.

METHODS

Paraffin-embedded sections of tumors and all histologically tumor-free margins were analyzed for the presence or absence of 4E, p53, and MMP-9 with immunohistochemical analysis. Patients were followed according to the institution's head and neck cancer protocol, and time to recurrence was noted.

RESULTS

Ninety-eight percent of tumors overexpressed 4E, 65% overexpressed p53, and 92% overexpressed MMP-9. Of the 52 patients with tumor-free margins, 52%, 46%, and 54% had positive margins for 4E, p53, and MMP-9, respectively. Although no significant correlation between 4E and p53 expression was seen in the margins (P =.16), a significant correlation between 4E and MMP-9 expression was noted (P =.0002). However, when expression of 4E and p53 in the margins of only the patients who overexpressed p53 in the tumors was compared (n = 34), there was a significant correlation (P =.04). There was also a significant difference in the disease-free interval between patients with 4E-positive and 4E-negative margins (P =.003). This difference in time to recurrence was not significant for the p53-positive versus the p53-negative group (P =.18) but approached significance when MMP-9 was used as a marker (P =.07). Although the univariate analysis showed that stage, nodal disease, grade, and 4E expression in the margins were significantly associated with disease-free interval, in the Cox multiple regression analysis, only 4E expression in the margin was significantly associated with disease-free interval (P =.01).

CONCLUSIONS

The era for molecular analysis of surgical margins is here. Although a significant correlation was seen between 4E and MMP-9, overexpression of 4E appears to be a significant predictor of recurrence when compared with the well-studied tumor suppressor gene p53 and a relatively novel marker, MMP-9.

Expression of matrix metalloproteinase 1, matrix metalloproteinase 2, and matrix metalloproteinase 9 in carcinoma of the head and neck

BACKGROUND

Numerous reports have documented a direct involvement of matrix metalloproteinase (MMP) overexpression in the development and progression of head and neck squamous cell carcinoma (HNSCC). In this study, the authors examined whether the expression of MMPs in HNSCC is correlated with other steps involved in tumor growth and metastasis, like angiogenesis, activation the nitric oxide (NO) pathway, and alteration of the p53 tumor suppressor gene.

METHODS

MMP-1, MMP-2, and MMP-9 expression levels were examined immunohistochemically in samples from 43 patients with HNSCC. Microvessel density (MVD) was determined by immunostaining of endothelial cells with anti-CD31 monoclonal antibody. Inducible nitric oxide synthase (iNOS) activity and cyclic guanosine monophosphatate (cGMP) levels were assessed in fresh tumor samples, whereas exons 5-9 of the p53 gene were analyzed by reverse transcriptase-polymerase chain reaction, single-strand conformation polymorphism analysis and were sequenced.

RESULTS

MMP-1 overexpression (>10% of tumor cells) was identified in 32 tumors (74.5%), whereas elevated levels of MMP-2 and MMP-9 were detected in 17 tumors (39.5%) each. Tumors with MMP-9 overexpression were characterized by significantly higher MVD (P = 0.05) and significantly higher iNOS activity and cGMP levels (P = 0.005 and P = 0.02, respectively). Moreover, p53 mutation was associated strongly with MMP-9 overexpression (P = 0.004). Conversely, no correlation was found between MMP-1 and MMP-2 expression, angiogenesis, iNOS activity, cGMP levels, and p53 mutation in this series.

CONCLUSIONS

This study documents the existence of a correlation between MMP-9 expression, activity of the iNOS pathway, p53 status, and angiogenesis in patients with HNSCC. This raises the possibility that p53 mutation, which frequently is present in HNSCC, may result in increased angiogenesis and invasiveness related to increased nitric oxide and MMP production by tumor cells, ultimately contributing to tumor progression.

Matrix metalloproteinase 13 activity is associated with poor prognosis in colorectal cancer

AIMS

The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes collectively capable of degrading all extracellular matrix components, in particular fibrillar collagen. The importance of this group of proteins in the processes of tumour invasion and metastasis is now widely acknowledged. MMP-13 (collagenase 3) has a central role in the MMP activation cascade. The purpose of this study was to investigate the presence and activity of MMP-13 in colorectal cancer and relate these to clinicopathological features.

METHODS

Immunohistochemistry for MMP-13 was performed on formalin fixed, paraffin wax embedded sections of a large series of colorectal cancers (n = 249), all of which had uniform clinical and pathological information available. Immunoreactivity to MMP-13 was detected with a monoclonal antibody to MMP-13 using a Dako TechMate 500 automated immunostaining system. The presence and cellular localisation of MMP-13 was assessed using a semiquantitative scoring system. Gelatin zymography was used to detect and measure MMP-13 activity. The zymography was performed on a subset of the cases studied by immunohistochemistry using two groups of 10 paired Dukes's C tumours and normal samples, selected by either having "good" or "poor" survival.

RESULTS

Immunoreactivity to MMP-13 was identified in 91% of cases and immunoreactivity was localised to the cytoplasm of tumour cells. A high MMP-13 staining score showed a trend towards poorer survival. Tumours had significantly greater MMP-13 activity compared with normal colonic mucosa (p < 0.001). Furthermore, the tumour to normal tissue ratio was significantly higher in the poor survival group (p = 0.02).

CONCLUSIONS

These results show that MMP-13 is frequently present and active in colorectal cancer and suggest that the activity of MMP-13 is associated with poorer survival in colorectal cancer.

Immunohistochemical analysis of matrix metalloproteinase-1, -3, and -13 in naturally occurring cartilaginous tumors of dogs

OBJECTIVE

To determine immunoreactivity of matrix metalloproteinase (MMP)-1, -3, and -13 in cartilaginous tumors of dogs, correlate expression of MMP with histologic grade of tumors and clinical outcome of dogs, and compare MMP immunoreactivity between chondrosarcomas and chondromas.

SAMPLE POPULATION

Formalin-fixed, paraffin-embedded tissues obtained from samples of naturally occurring chondrosarcomas (n = 31) and chondromas (8) of dogs that were submitted to our veterinary medical diagnostic laboratory.

PROCEDURE

Histologic sections from each sample were stained with H&E and monoclonal antibody to MMP-1, -3, and -13 by use of an avidin-peroxidase immunohistochemical technique. For each section, histologic grade (I, II, or III) and immunohistochemical expression (0, 1, 2, or 3) were evaluated. Clinical outcome was obtained from medical records or interviews with referring veterinarians and scored as a good outcome, moderate outcome, or poor outcome. Correlations among variables and differences between chondrosarcomas and chondromas were analyzed.

RESULTS

Samples from chondrosarcomas had significantly higher immunoreactivity of MMP-1 and -13, compared with immunoreactivity in samples from chondromas. In chondrosarcomas, a significant positive correlation (r, 0.386) was found between MMP-1 and -13 immunoreactivities, and a significant negative correlation (r, -0.390) was detected between MMP-3 and -13 immunoreactivities.

CONCLUSIONS AND CLINICAL RELEVANCE

A significant increase in expression of collagenases (MMP-1 and -13) in chondrosarcomas, compared with expression in chondromas, suggests that collagenases may play an important role in tumor progression, and possibly metastasis, in chondrosarcomas of dogs.