Proteolytic activity of human lymphoid tumor cells. Correlation with tumor progression

Patterns of Gene Expression in Cutaneous T-Cell Lymphoma: Systematic Review of Transcriptomic Studies in Mycosis Fungoides

Mycosis fungoides (MF) is the most prevalent type of skin lymphoma. In its early stages, it has a favorable prognosis. However, in its late stages, it is associated with an increased risk of mortality. This systematic review aimed to identify the transcriptomic changes involved in MF pathogenesis and progression. A literature search was conducted using the database PubMed, followed by the extraction of 2245 genes which were further filtered to 150 recurrent genes that appeared in two or more publications. Categorization of these genes identified activated pathways involved in pathways such as cell cycle and proliferation, chromosomal instability, and DNA repair. We identified 15 genes implicated in MF progression, which were involved in cell proliferation, immune checkpoints, resistance to apoptosis, and immune response. In highlighting the discrepancies in the way MF transcriptomic data is obtained, further research can focus on not only unifying their approach but also focus on the 150 pertinent genes identified in this review.

Efficacy of doxycycline in the treatment of early stages of mycosis fungoides: a randomized controlled trial

BACKGROUND

Mycosis fungoides is the most common type of primary cutaneous T cell lymphomas. Doxycycline promoted apoptosis in different human malignant cell lines and in vivo models.

OBJECTIVES

To test for the therapeutic efficacy of doxycycline in comparison to PUVA in early stages of classic MF and its effect on T cell apoptosis.

METHODS

Thirty-six patients were randomized into either: doxycycline 200 mg daily (n = 18) or PUVA (3 weekly sessions) (n = 18) for 12 weeks. The primary outcome (therapeutic efficacy) was defined in terms of objective response rate (ORR) which was measured according to changes in the modified severity weighted assessment tool (mSWAT).

RESULTS

Doxycycline achieved significantly less ORR (partial response) in comparison to PUVA (11.1%, 50%, respectively, p = .016). The percent reduction in mSWAT, CAILS, histopathology score and CD3 expression was significantly less in the doxycycline group (p = .001, p = .001, p ˂ .001, and p = .004, respectively). Within the doxycycline group, changes in mSWAT and CAILS showed no correlation with changes in the CD3 or Bcl-2 expression. Gastric upset was significantly more encountered in the doxycycline group (p = .001).

CONCLUSION

Doxycycline is not suitable as a sole agent in the treatment of early stages of classic MF, acting mainly by anti-inflammatory rather apoptotic function.

REGISTER NUMBER

NCT03454945 (www.clinicaltrials.gov).

Exocellular extract of Fusarium oxysporum, fungus free, is able to permeate and act selectively in skin

The skin is an important gateway for Fusarium infection in humans. Our hypothesis is that metabolites produced by Fusarium oxysporum should change the barrier structure to permeate the skin. Male Wistar rats received a topical application of a solution (0.05 mg/mL) of Fusarium metabolites. The animals were euthanized 3, 6, 12, 24 h after and the skin was processed for immunostaining by laminin and E-cadherin to investigate whether the Fusarium metabolites can break the barrier of healthy skin. Other techniques were employed: H&E to study the morphology; metalloproteinase-9 (MMP-9), TUNEL, and PCNA immunostaining to evaluate the inflammation, cell death, and proliferation, respectively. There was an inflammatory response mainly centered in the dermis. Qualitatively, the skin of the experimental group showed reduced E-cadherin and laminin immunostaining at 3, 12, and 24 h. Higher intensity staining by TUNEL at 3 h, and PCNA at 6, 12, and 24 h. There was intense MMP-9 activity at 6, 12, and 24 h. None of analyses revealed any changes in the epidermis. It was concluded that the fraction was able to permeate the skin and act selectively in dermis, inducing inflammatory response, increasing MMP-9 immunostaining, inducing apoptosis, and reducing E-cadherin and laminin immunostaining.

Abnormalities in alternative splicing of angiogenesis-related genes and their role in HIV-related cancers

Alternative splicing of mRNA leads to an increase in proteome biodiversity by allowing the generation of multiple mRNAs, coding for multiple protein isoforms of various structural and functional properties from a single primary pre-mRNA transcript. The protein isoforms produced are tightly regulated in normal development but are mostly deregulated in various cancers. In HIV-infected individuals with AIDS, there is an increase in aberrant alternative splicing, resulting in an increase in HIV/AIDS-related cancers, such as Kaposi’s sarcoma, non-Hodgkin’s lymphoma, and cervical cancer. This aberrant splicing leads to abnormal production of protein and is caused by mutations in cis-acting elements or trans-acting factors in angiogenesis-related genes. Restoring the normal regulation of alternative splicing of angiogenic genes would alter the expression of protein isoforms and may confer normal cell physiology in patients with these cancers. This review highlights the abnormalities in alternative splicing of angiogenesis-related genes and their implication in HIV/AIDS-related cancers. This allows us to gain an insight into the pathogenesis of HIV/AIDS-related cancer and in turn elucidate the therapeutic potential of alternatively spliced genes in HIV/AIDS-related malignancies.

Whole-exome sequencing of primary plasma cell leukemia discloses heterogeneous mutational patterns

Primary plasma cell leukemia (pPCL) is a rare and aggressive form of plasma cell dyscrasia and may represent a valid model for high-risk multiple myeloma (MM). To provide novel information concerning the mutational profile of this disease, we performed the whole-exome sequencing of a prospective series of 12 pPCL cases included in a Phase II multicenter clinical trial and previously characterized at clinical and molecular levels. We identified 1, 928 coding somatic non-silent variants on 1, 643 genes, with a mean of 166 variants per sample, and only few variants and genes recurrent in two or more samples. An excess of C > T transitions and the presence of two main mutational signatures (related to APOBEC over-activity and aging) occurring in different translocation groups were observed. We identified 14 candidate cancer driver genes, mainly involved in cell-matrix adhesion, cell cycle, genome stability, RNA metabolism and protein folding. Furthermore, integration of mutation data with copy number alteration profiles evidenced biallelically disrupted genes with potential tumor suppressor functions. Globally, cadherin/Wnt signaling, extracellular matrix and cell cycle checkpoint resulted the most affected functional pathways. Sequencing results were finally combined with gene expression data to better elucidate the biological relevance of mutated genes. This study represents the first whole-exome sequencing screen of pPCL and evidenced a remarkable genetic heterogeneity of mutational patterns. This may provide a contribution to the comprehension of the pathogenetic mechanisms associated with this aggressive form of PC dyscrasia and potentially with high-risk MM.

Prolyl-isomerase Pin1 controls Notch3 protein expression and regulates T-ALL progression

Deregulated Notch signaling is associated with T-cell Acute Lymphoblastic Leukemia (T-ALL) development and progression. Increasing evidence reveals that Notch pathway has an important role in the invasion ability of tumor cells, including leukemia, although the underlying molecular mechanisms remain mostly unclear. Here, we show that Notch3 is a novel target protein of the prolyl-isomerase Pin1, which is able to regulate Notch3 protein processing and to stabilize the cleaved product, leading to the increased expression of the intracellular domain (N3_IC), finally enhancing Notch3-dependent invasiveness properties. We demonstrate that the combined inhibition of Notch3 and Pin1 in the Notch3-overexpressing human leukemic TALL-1 cells reduces their high invasive potential, by decreasing the expression of the matrix metalloprotease MMP9. Consistently, Pin1 depletion in a mouse model of Notch3-induced T-ALL, by reducing N3_IC expression and signaling, impairs the expansion/invasiveness of CD4⁺CD8⁺ DP cells in peripheral lymphoid and non-lymphoid organs. Notably, in in silico gene expression analysis of human T-ALL samples we observed a significant correlation between Pin1 and Notch3 expression levels, which may further suggest a key role of the newly identified Notch3-Pin1 axis in T-ALL aggressiveness and progression. Thus, combined suppression of Pin1 and Notch3 proteins may be exploited as an additional target therapy for T-ALL.

Plasma matrix metalloproteinase-9 activity in cats with lymphoma

In this study, plasma MMP-9 activity was evaluated in cats with lymphoma. Plasma samples were obtained from 26 cats with lymphoma before treatment. From 13 of the included 26 cats, plasma samples were obtained 4 weeks after the initiation of treatment. Plasma samples were also obtained from 10 healthy cats as a control. Plasma MMP-9 activity was examined by gelatin zymography and semi-quantitative value (arbitrary unit; a.u.) for each sample was calculated. Relatively high levels of MMP-9 were observed in cats with lymphoma compared with those in healthy control cats. MMP-9 quantification through zymography showed significantly higher activity in cats with lymphoma (median, 0.63 a.u.; range, 0.23-3.24 a.u.) than in healthy controls (0.22 a.u.; 0.12-0.46 a.u.; P < 0.01). MMP-9 activities were significantly different before (0.73 a.u.; 0.30-3.24 a.u.) and after treatment (0.50 a.u.; 0.14-1.32 a.u.; P = 0.017). Measuring plasma MMP-9 activity in cats with lymphoma may become an appropriate monitoring tool for feline lymphoma.

The role of angiogenesis in human non-Hodgkin lymphomas

The role of angiogenesis in the growth of lymphomas and survival of patients with leukemias and other hematological malignancies has become evident since 1994. Angiogenic factors, such as vascular endothelial growth factor and its receptors together with other tumor microenvironment components, including myelo-monocytic cell, mast cells, endothelial progenitor cells, and circulating endothelial cells, have been shown to be important in the progression and maintenance of lymphoproliferative disorders. In this review article, we present an overview of the literature focusing on the relationship between angiogenesis and disease progression and the recent advantages in the antiangiogenic treatment in human non-Hodgkin lymphomas.

The role of vascular endothelial growth factor and matrix metalloproteinases in canine lymphoma: in vivo and in vitro study

BACKGROUND

Canine lymphoma represents the most frequent haematopoietic cancer and it shares some similarities with human non-Hodgkin lymphoma. Matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) play a coordinated role during invasion and proliferation of malignant cells; however, little is known about their role in canine haematologic malignancies. The aim of this study was to investigate the mRNA and protein expression of VEGF and the most relevant MMPs in canine lymphoma. Lymph node aspirates from 26 B-cell and 21 T-cell lymphomas were collected. The protein expression levels of MMP-9, MMP-2 and VEGF-A were evaluated by immunocytochemistry, and the mRNA levels of MMP-2, MMP-9, MT1-MMP, TIMP-1, TIMP-2, RECK, VEGF-A and VEGF-164 were measured using quantitative RT-PCR.

RESULTS

MT1-MMP, TIMP-1 and RECK mRNA levels were significantly higher in T-cell lymphomas than in B-cell lymphomas. Higher mRNA and protein levels of MMP-9 and VEGF-A were observed in T-cell lymphomas than in B-cell lymphomas and healthy control lymph nodes. A positive correlation was found between MMP-9 and VEGF-A in T-cell lymphomas. Moreover, MMP-9, MT1-MMP, TIMP-1 and VEGF-A were expressed at the highest levels in high-grade T-cell lymphomas.

CONCLUSIONS

This study provides new information on the expression of different MMPs and VEGF in canine lymphoma, suggesting a possible correlation between different MMPs and VEGF, immunophenotype and prognosis.

α2β1 integrin promotes chemoresistance against doxorubicin in cancer cells through extracellular signal-regulated kinase (ERK)

The role and the mechanisms by which β1 integrins regulate the survival and chemoresistance of T cell acute lymphoblastic leukemia (T-ALL) still are poorly addressed. In this study, we demonstrate in T-ALL cell lines and primary blasts, that engagement of α2β1 integrin with its ligand collagen I (ColI), reduces doxorubicin-induced apoptosis, whereas fibronectin (Fn) had no effect. ColI but not Fn inhibited doxorubicin-induced mitochondrial depolarization, cytochrome c release, and activation of caspase-9 and -3. ColI but not Fn also prevented doxorubicin from down-regulating the levels of the prosurvival Bcl-2 protein family member Mcl-1. The effect of ColI on Mcl-1 occurred through the inhibition of doxorubicin-induced activation of c-Jun N-terminal kinase (JNK). Mcl-1 knockdown experiments showed that the maintenance of Mcl-1 levels is essential for ColI-mediated T-ALL cell survival. Furthermore, activation of MAPK/ERK, but not PI3K/AKT, is required for ColI-mediated inhibition of doxorubicin-induced JNK activation and apoptosis and for ColI-mediated maintenance of Mcl-1 levels. Thus, our study identifies α2β1 integrin as an important survival pathway in drug-induced apoptosis of T-ALL cells and suggests that its activation can contribute to the generation of drug resistance.

Novel insights into the role of interleukin-27 and interleukin-23 in human malignant and normal plasma cells

Multiple myeloma is a monoclonal postgerminal center tumor that has phenotypic features of plasmablasts and/or plasma cells and usually localizes at multiple sites in the bone marrow. The pathogenesis of multiple myeloma is complex and dependent on the interactions between tumor cells and their microenvironment. Different cytokines, chemokines, and proangiogenic factors released in the tumor microenvironment are known to promote multiple myeloma cell growth. Here, we report recent advances on the role of 2 strictly related immunomodulatory cytokines, interleukin-27 (IL-27) and IL-23, in human normal and neoplastic plasma cells, highlighting their ability to (i) act directly against multiple myeloma cells, (ii) influence the multiple myeloma microenvironment by targeting osteoclast and osteoblast cells, and (iii) modulate normal plasma cell function. Finally, the therapeutic implication of these studies is discussed.

Matrix metalloproteinase-2 promoter genotype as a marker of cutaneous T-cell lymphoma early stage

The aim of the study was to investigate the DNA polymorphic genotype in MMP-2 promoter gene as a potential candidate region for the development of the cutaneous T-cell lymphoma (CTCL) and/or its progression. A total of 89 Czech patients with CTCL (including 23 patients with large plaque parapsoriasis) were compared to 198 controls of similar age and sex distribution, without personal or family history of chronic skin diseases and without personal history of malignancy. The three selected polymorphisms in the promoter of MMP-2 gene (−1575G/A, −1306C/T, and −790T/G) were determined using the PCR-based methodology with RFLP. In our cohort, the associated GGCCTT MMP-2 promoter genotype was highly significantly more frequent in CTCL-Ia stage patients compared to patients with parapsoriasis, the tests having high sensitivity and specificity (78%, 83%, resp.). To conclude, use of associated MMP-2 promoter genotype as a DNA marker might make it possible to distinguish between the patients with parapsoriasis and those with CTCL stage Ia, which could substantially improve possibilities of clinical diagnostics, therapy design, and prognosis of this serious condition in the early stages.

Lack of prognostic value of MMP-9 expression and immunohistochemically defined germinal center phenotype in patients with diffuse large B-cell lymphoma treated with modern chemotherapy with or without CD20 antibody

Diffuse large B-cell lymphomas (DLBCLs) are a heterogeneous group of lymphomas, with no accepted biological prognostic markers in routine clinical practice. Previously, matrix metalloproteinase (MMP-9), tissue inhibitors of matrix metalloproteinase (TIMP)- 1 and non-germinal center (GC) phenotype have been shown to associate with poor prognosis in DLBCL patients. The aim of this study was to find out whether tissue expression of gelatinases (MMP-2 and MMP-9) or their tissue inhibitors (TIMP-1 and TIMP-2) or immunohistochemically defined GC phenotype could act as prognostic markers in patients treated with modern treatments. Additionally, correlations between these proteins and GC phenotype were investigated. GC phenotype and tissue expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 were analyzed by immunohistochemistry in tissue samples from 114 DLBCL patients. In this study, in patients treated with modern lymphoma treatments (5-year cause-specific survival 69.8%) MMP-2, MMP-9, TIMP-1 or TIMP-2 expression or GC phenotype did not correlate with survival. International Prognostic Index (IPI) and stage were the only factors, which retained their prognostic significance in this patient material. Gelatinases or TIMPs did not correlate with GC phenotype, either. Prognostic markers are dependent on the lymphoma treatments used. In DLBCL patients treated with modern chemotherapy with or without rituximab, MMP-9, TIMP-1 and GC phenotype seem to have lost their prognostic value.

Bone marrow angiogenesis in multiple myeloma

Angiogenesis is a constant hallmark of multiple myeloma (MM) progression and has prognostic potential. It is induced by plasma cells via angiogenic factors with the transition from monoclonal gammopathy of undetermined significance (MGUS) to MM, and probably with loss of angiostatic activity on the part of MGUS. The pathophysiology of MM-induced angiogenesis is complex and involves both direct production of angiogenic cytokines by plasma cells and their induction within the microenvironment. The latter are secreted by stromal cells, endothelial cells (EC) and osteoclasts, and promote plasma cell growth, survival and migration, as well as paracrine cytokine secretion and angiogenesis in the bone marrow milieu. Angiogenesis is also supported by inflammatory cells following their recruitment and activation by plasma cells. Finally, circulating EC and endothelial precursor cells (EPC) contribute to the neovascularization, and the presence of EPC suggests that vasculogenesis (new vessel formation from EPC) may also contribute to the full MM vascular tree.

Increased matrix-metalloproteinase-2 and matrix-metalloproteinase-9 expression in the brain of dystrophic mdx mouse

Brain edema and severe alterations of the glial and endothelial cells have recently been demonstrated in the dystrophin-deficient mdx mouse, an experimental model of Duchenne muscular dystrophy, and an increase in microvessel density in patients affected by Duchenne muscular dystrophy has also been shown. In order to further elucidate the mechanisms underlying the angiogenetic processes occurring in Duchenne muscular dystrophy, in this study we analyzed matrix-metalloproteinase-2 and -9 expression in the brain of 20-month-old mdx and control mice by means of immunohistochemistry, in situ hybridization, immunoblotting and gelatin zymography. Moreover, we studied vascular endothelial growth factor expression by means of Western blot and immunohistochemistry, and by dual immunofluorescence using anti-vascular endothelial growth factor and anti matrix-metalloproteinase-2 and-9 antibodies. Ultrastructural features of the brain choroidal plexuses were evaluated by electron microscopy. Spatial relationships between endothelium and astrocyte processes were studied by confocal laser microscopy, using an anti-CD31 antibody as a marker of endothelial cells, and anti-glial fibrillary acidic protein (GFAP) as a marker of glial cells. The results demonstrate that high expression of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 protein content occurs in mdx brain and in choroidal plexuses where, by in situ hybridization, matrix-metalloproteinase-2 and matrix-metalloproteinase-9 mRNA was localized in the epithelial cells. Moreover, matrix-metalloproteinase-2 mRNA was found in both mdx perivascular astrocytes and blood vessels, while matrix-metalloproteinase-9 mRNA was localized in mdx vessels. Through zymography, increased expression of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 was found in mdx brain compared with the controls. These enhanced matrix-metalloproteinase levels in mdx mice were found to be associated with increased vascular endothelial growth factor expression, as determined by immunoblotting and immunocytochemistry and with ultrastructural alterations of the mdx choroidal epithelial cells and brain vessels, as previously reported [Nico B, Frigeri A, Nicchia GP, Corsi P, Ribatti D, Quondamatteo F, Herken R, Girolamo F, Marzullo A, Svelto M, Roncali L (2003) Severe alterations of endothelial and glial cells in the blood-brain barrier of dystrophic mdx mice. Glia 42:235-251]. Indeed, in the mdx epithelial cells of the plexuses, the apical microvilli were located on the lateral membranes, whereas in the controls they were uniformly distributed over the free ventricular surface. Moreover, by dual immunofluorescence, a colocalization of vascular endothelial growth factor and matrix-metalloproteinase-2 and matrix-metalloproteinase-9 was found in the ependymal and epithelial cells of plexuses in mdx mice and, under confocal laser microscopy, mdx CD-31 positive vessels were enveloped by less GFAP-positive astrocyte processes than the controls. Overall, these data point to a specific pathogenetic role of matrix-metalloproteinase-2 and matrix-metalloproteinase-9 in neurological dysfunctions associated with Duchenne muscular dystrophy.

The role of matrix metalloproteinase 9 in the pathogenesis of chronic lymphocytic leukaemia

Matrix metalloproteinases (MMPs) are important for the pathogenesis and progression of different tumours. MMPs-2 and -9 are the principal MMPs produced by lymphocytes; these enzymes can degrade a number of matrix proteins but are the two main MMPs that digest type IV collagen, the major component of basement membranes. Therefore, these enzymes are potentially important for tissue invasion and remodelling by malignant lymphocytes. This study showed that chronic lymphocytic leukaemia (CLL) cells produce and secrete variable amounts of pro-MMP-9, but no MMP-2 or tissue inhibitor of metalloproteinase 1 (TIMP-1). The pro-enzyme was found in monomeric and dimeric forms and also complexed with lipocalin. Moreover, a small fraction of secreted monomer became associated with the cell surface and activated upon cell adhesion to insolubilized type IV collagen. High levels of intracellular MMP-9 were associated with advanced (stage C) disease and with poor patient survival. Immunohistochemical studies demonstrated that MMP-9 was associated with areas of tissue invasion and remodelling. The relatively specific MMP-9 inhibitors, Ro31-9790 (3 micromol/l) and TIMP-1, reduced CLL-cell migration through type IV collagen and through endothelial monolayers suggesting that the enzyme may also be important in malignant cell entry and egress to and from involved tissue. Our data raise the possibility that MMP-9 modulation may have therapeutic potential in advanced CLL.

Prognostic value of matrix metalloproteinases (MMP-2 and MMP-9) in Hodgkin's and non-Hodgkin's lymphoma

Matrix metalloproteinases (MMPs) are responsible for the degradation of extracellular matrix and have an important role in tumour metastases. We investigated the role of MMP-2 and MMP-9 in Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). The serum samples of patients with HD (n = 12), NHL (n = 30) and healthy control (n = 22) were analysed for MMP-2 and MMP-9. An immunoassay method was used for the determination of MMP-2 and MMP-9 levels. No statistical significance was found between HD and NHL groups for levels of MMP-2. There were no relation between MMP-2, MMP-9 levels and clinical characteristics of patients. The mean MMP-9 levels were found to be 555.6 +/- 140 ng/ml, 446.6 +/- 53.6 ng/ml and 111.2 +/- 10.3 ng/ml in HD, NHL and control groups, respectively. Our results suggest that MMP-9 levels are substantially increased in HD and NHL when compared with controls and may probably be used for distinguishing the benign diseases from malign lymphomas.

Evidence for the role of promoter methylation in the regulation of MMP-9 gene expression

Several studies have reported that elevated MMP-9 expression in lymphoma tissues correlated with tumor stage, grade, or prognosis. Because the DNA methylation pattern is critical for gene expression, detailed methylation analysis using genomic bisulfite sequencing was performed on a series of lymphoma cell lines. We found an inverse correlation between level of methylation of the MMP-9 promoter and the level of MMP-9 expression. Treating lymphoma cells with a DNA methylation inhibitor decreased MMP-9 promoter methylation and increased MMP-9 messenger RNA and protein secretion. This increased expression was potentiated by PMA, a known stimulus of MMP-9 in lymphoma cells. Finally, experiments using in vitro methylated MMP-9 promoter constructs confirmed the fact that DNA methylation exerts suppression on transcriptional activity. The results thus indicate that methylation may contribute to the transcriptional activity of the MMP-9 promoter.

Matrix metalloproteinase-2 in pancreatic juice for diagnosis of pancreatic cancer

INTRODUCTION

Matrix metalloproteinase-2 (MMP-2) has an activity to degrade type IV collagen and is associated with invasion angiogenesis of malignant tumor.

AIM

A diagnostic value of MMP-2 in pancreatic juice was studied in the diagnosis of pancreatic cancer.

METHODOLOGY

Using gelatin zymography, active MMP-2 and proMMP-2 were determined in pancreatic juice obtained endoscopically from 12 patients with pancreatic cancer, 11 with chronic pancreatitis, and 7 control subjects.

RESULTS

ProMMP-2 was detected in 12 of 12 patients (100%) with pancreatic cancer, 6 of 11 (54.5%) with chronic pancreatitis, and 3 of 7 (42.9%) controls. Active MMP-2 was detected in 11 patients (91.6%) with pancreatic cancer, 2 (18.2%) with chronic pancreatitis, and none of the control subjects. An activation ratio of MMP-2 (active MMP-2/total MMP-2) in pancreatic juice is significantly higher in pancreatic cancer (23.4 +/- 4.4%, mean +/- SE) than in chronic pancreatitis (2.1 +/- 1.7%) and controls (0%) (p < 0.01). Active MMP-2 was also detected in pancreatic juice from three cases of small pancreatic cancer (tumor <2 cm in diameter).

CONCLUSION

Our observation suggests that detection of active MMP-2 in pancreatic juice using gelatin zymography may be useful for the diagnosis of pancreatic cancer.