The matrix metalloproteinases and their inhibitors in the treatment of pancreatic cancer

Phage-based peptides for pancreatic cancer diagnosis and treatment: alternative approach

Pancreatic cancer is a devastating disease with a high mortality rate and a lack of effective therapies. The challenges associated with early detection and the highly aggressive nature of pancreatic cancer have limited treatment options, underscoring the urgent need for better disease-modifying therapies. Peptide-based biotherapeutics have become an attractive area of research due to their favorable properties such as high selectivity and affinity, chemical modifiability, good tissue permeability, and easy metabolism and excretion. Phage display, a powerful technique for identifying peptides with high affinity and specificity for their target molecules, has emerged as a key tool in the discovery of peptide-based drugs. Phage display technology involves the use of bacteriophages to express peptide libraries, which are then screened against a target of interest to identify peptides with desired properties. This approach has shown great promise in cancer diagnosis and treatment, with potential applications in targeting cancer cells and developing new therapies. In this comprehensive review, we provide an overview of the basic biology of phage vectors, the principles of phage library construction, and various methods for binding affinity assessment. We then describe the applications of phage display in pancreatic cancer therapy, targeted drug delivery, and early detection. Despite its promising potential, there are still challenges to be addressed, such as optimizing the selection process and improving the pharmacokinetic properties of phage-based drugs. Nevertheless, phage display represents a promising approach for the development of novel targeted therapies in pancreatic cancer and other tumors.

Drug Delivery Strategies for the Treatment of Pancreatic Cancer

Pancreatic cancer is fast becoming a global menace and it is projected to be the second leading cause of cancer-related death by 2030. Pancreatic adenocarcinomas, which develop in the pancreas' exocrine region, are the predominant type of pancreatic cancer, representing about 95% of total pancreatic tumors. The malignancy progresses asymptomatically, making early diagnosis difficult. It is characterized by excessive production of fibrotic stroma known as desmoplasia, which aids tumor growth and metastatic spread by remodeling the extracellular matrix and releasing tumor growth factors. For decades, immense efforts have been harnessed toward developing more effective drug delivery systems for pancreatic cancer treatment leveraging nanotechnology, immunotherapy, drug conjugates, and combinations of these approaches. However, despite the reported preclinical success of these approaches, no substantial progress has been made clinically and the prognosis for pancreatic cancer is worsening. This review provides insights into challenges associated with the delivery of therapeutics for pancreatic cancer treatment and discusses drug delivery strategies to minimize adverse effects associated with current chemotherapy options and to improve the efficiency of drug treatment.

Microenvironmental Determinants of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) belongs to the most lethal solid tumors in humans. A histological hallmark feature of PDAC is the pronounced tumor microenvironment (TME) that dynamically evolves during tumor progression. The TME consists of different non-neoplastic cells such as cancer-associated fibroblasts, immune cells, endothelial cells, and neurons. Furthermore, abundant extracellular matrix components such as collagen and hyaluronic acid as well as matricellular proteins create a highly dynamic and hypovascular TME with multiple biochemical and physical interactions among the various cellular and acellular components that promote tumor progression and therapeutic resistance. In recent years, intensive research efforts have resulted in a significantly improved understanding of the biology and pathophysiology of the TME in PDAC, and novel stroma-targeted approaches are emerging that may help to improve the devastating prognosis of PDAC patients. However, none of anti-stromal therapies has been approved in patients so far, and there is still a large discrepancy between multiple successful preclinical results and subsequent failure in clinical trials. Furthermore, recent findings suggest that parts of the TME may also possess tumor-restraining properties rendering tailored therapies even more challenging.

Cancer-Associated Fibroblasts in Pancreatic Cancer: Should They Be Deleted or Reeducated?

Pancreatic ductal adenocarcinoma is characterized by an extensive stromal response called desmoplasia. Within the tumor stroma, cancer-associated fibroblasts (CAFs) are the primary cell type. CAFs have been shown to play a role in pancreatic cancer progression; they secrete growth factors, inflammatory cytokines, and chemokines that stimulate signaling pathways in cancer cells and modulate the cancer biology toward increased aggressiveness. Therefore, targeting CAFs may serve as a powerful weapon against pancreatic cancer and improve therapeutic effects. However, a previous study aiming to deplete CAFs by inhibiting sonic Hedgehog signaling failed to show any benefit in survival time of pancreatic cancer patients. We reported that the natural product curcumin reeducated CAFs in pancreatic cancer treatment. A low concentration of curcumin reversed the activation of fibroblasts without exhibiting growth suppression effects. In addition, curcumin suppressed CAF-induced pancreatic cancer cell migration and invasion in vitro and lung metastasis in vivo. The results of our study suggest that active CAFs can be inactivated by certain natural products such as curcumin. Reeducation of CAFs back to their normal state, rather than their indiscriminate depletion, may broaden our view in the development of therapeutic options for the treatment of pancreatic cancer.

Do anti-stroma therapies improve extrinsic resistance to increase the efficacy of gemcitabine in pancreatic cancer?

Pancreatic ductal adenocarcinoma (PDAC) is among the most devastating human malignancies, with approximately 20-30% of PDAC patients receiving the surgical resection with curative intent. Although many studies have focused on finding ideal "drug chaperones" that facilitate and/or potentiate the effects of gemcitabine (GEM) in pancreatic cancer, a significant benefit in overall survival could not be demonstrated for any of these combination therapies in PDAC. Given that pancreatic cancer is characterized by desmoplasia and the dual biological roles of stroma in pancreatic cancer, we reassess the importance of stroma in GEM-based therapeutic approaches in light of current findings. This review is focused on understanding the role of stromal components in the extrinsic resistance to GEM and whether anti-stroma therapies have a positive effect on the GEM delivery. This work contributes to the development of novel and promising combination GEM-based regimens that have achieved significant survival benefits for the patients with pancreatic cancer.

Molecular-Targeted Agents in Pancreatic Cancer

Background

Despite the acceptance of gemcitabine as the standard first-line agent for the treatment of advanced pancreatic cancer as well as the improved response rates seen with gemcitabine combinations, novel therapies are needed for this disease, which has one of the lowest survival rates. The growing understanding of the molecular basis of pancreatic cancer and the recent introduction of targeted therapeutic agents have initiated novel studies that have the potential to improve on existing treatments.

Methods

We review the rationale and the clinical studies of therapeutic agents that target some of the molecular abnormalities commonly found in pancreatic cancer.

Results

Matrix metalloproteinase inhibitors (MMPIs), farnesyltransferase inhibitors (FTIs), and tyrosine-kinase inhibitors and monoclonal antibodies against growth factors or their receptors are novel agents that have undergone phase II or III trials. Phase III studies of MMPIs, alone or in combination with gemcitabine, and phase III studies of FTIs have produced disappointing results. Other agents in earlier phases of clinical development remain promising.

Conclusions

Despite the negative studies of MMPIs and FTIs, the results of phase II trials of other drugs are encouraging. Targeted agents may improve the prognosis of pancreatic cancer.

Targeting stroma in pancreatic cancer: Promises and failures of targeted therapies

Desmoplasia or abundant fibrotic stroma is a typical property of most malignancies, which has a great effect on tumorigenesis, angiogenesis, and resistance to therapy. The activated stroma cells comprises several cell types including endothelial cells, nerve cells, inflammatory/macrophages cells, stellate cells, and extracellular matrix. In other word, the interactions of cancer-stroma modulate tumorigenesis, therapy resistance, and poor delivery of drugs. Therefore, targeting the tumor stroma in combination with conventional chemotherapeutic agents could provide a promising approach in the treatment of pancreatic cancer. This review summarizes the current knowledge about pancreatic stellate cells, targeting stroma compartments with particular emphasis on preclinical, and clinical trials on targeting of stroma as an option in pancreatic cancer treatment.

Pancreatic cancer: Stroma and its current and emerging targeted therapies

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal human malignancies with a 5-year survival rate of 8%. Dense, fibrotic stroma associated with pancreatic tumors is a major obstacle for drug delivery to the tumor bed and plays a crucial role in pancreatic cancer progression. Targeting stroma is considered as a potential therapeutic strategy to improve anti-cancer drug efficacy and patient survival. Although numerous stromal depletion therapies have reached the clinic, they add little to overall survival and are often associated with toxicity. Furthermore, increasing evidence suggests the anti-tumor properties of stroma. Its complete ablation enhanced tumor progression and reduced survival. Consequently, efforts are now focused on developing stromal-targeted therapies that normalize the reactive stroma and avoid the extremes: stromal abundance vs. complete depletion. In this review, we summarized the state of current and emerging anti-stromal targeted therapies, with major emphasis on the role of miRNAs in PDAC stroma and their potential use as novel therapeutic agents to modulate PDAC tumor-stromal interactions.

Insights into the distinct roles of MMP-11 in tumor biology and future therapeutics (Review)

The biological processes of cancer cells such as tumorigenesis, proliferation, angiogenesis, apoptosis and invasion are greatly influenced by the surrounding microenvironment. The ability of solid malignant tumors to alter the microenvironment represents an important characteristic through which tumor cells are able to acquire specific functions necessary for their malignant biological behaviors. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with the capacity of remodeling extracellular matrix (ECM) by degrading almost all ECM proteins, which plays essential roles during the invasion and metastasis process of solid malignant tumors, including allowing tumor cells to modify the ECM components and release cytokines, ultimately facilitating protease-dependent tumor progression. MMP-11, also named stromelysin-3, is a member of the stromelysin subgroup belonging to MMPs superfamily, which has been detected in cancer cells, stromal cells and adjacent microenvironment. Differently, MMP-11 exerts a dual effect on tumors. On the one hand MMP-11 promotes cancer development by inhibiting apoptosis as well as enhancing migration and invasion of cancer cells, on the other hand MMP-11 plays a negative role against cancer development via suppressing metastasis in animal models. Overexpression of MMP-11 was discovered in sera of cancer patients compared with normal control group as well as in multiple tumor tissue specimens, such as gastric cancer, breast cancer, and pancreatic cancer. At present, some evidence supports that MMP-11 may work as a significant tumor biomarker for early detection of cancer, tumor staging, prognostic analysis, monitoring recurrence during follow-up and also a potential target for immunotherapy against cancer. In view of the importance of MMP-11 in modifying tumor microenvironment and potent antitumoral effects on solid tumors, there is an urgent need for a deeper understanding of how MMP-11 modulates tumor progression, and exploring its potential clinical application.

Systemic delivery of microencapsulated 3-bromopyruvate for the therapy of pancreatic cancer

PURPOSE

This study characterized the therapeutic efficacy of a systemically administered formulation of 3-bromopyruvate (3-BrPA), microencapsulated in a complex with β-cyclodextrin (β-CD), using an orthotopic xenograft mouse model of pancreatic ductal adenocarcinoma (PDAC).

EXPERIMENTAL DESIGN

The presence of the β-CD-3-BrPA complex was confirmed using nuclear magnetic resonance spectroscopy. Monolayer as well as three-dimensional organotypic cell culture was used to determine the half-maximal inhibitory concentrations (IC50) of β-CD-3-BrPA, free 3-BrPA, β-CD (control), and gemcitabine in MiaPaCa-2 and Suit-2 cell lines, both in normoxia and hypoxia. Phase-contrast microscopy, bioluminescence imaging (BLI), as well as zymography and Matrigel assays were used to characterize the effects of the drug in vitro. An orthotopic lucMiaPaCa-2 xenograft tumor model was used to investigate the in vivo efficacy.

RESULTS

β-CD-3-BrPA and free 3-BrPA demonstrated an almost identical IC50 profile in both PDAC cell lines with higher sensitivity in hypoxia. Using the Matrigel invasion assay as well as zymography, 3-BrPA showed anti-invasive effects in sublethal drug concentrations. In vivo, animals treated with β-CD-3-BrPA demonstrated minimal or no tumor progression as evident by the BLI signal as opposed to animals treated with gemcitabine or the β-CD (60-fold and 140-fold signal increase, respectively). In contrast to animals treated with free 3-BrPA, no lethal toxicity was observed for β-CD-3-BrPA.

CONCLUSION

The microencapsulation of 3-BrPA represents a promising step towards achieving the goal of systemically deliverable antiglycolytic tumor therapy. The strong anticancer effects of β-CD-3-BrPA combined with its favorable toxicity profile suggest that clinical trials, particularly in patients with PDAC, should be considered.

Stroma and pancreatic ductal adenocarcinoma: an interaction loop

Pancreatic ductal adenocarcinoma (PDA) has two exceptional features. First, it is a highly lethal disease, with a median survival of less than 6 months and a 5-year survival rate less than 5%. Second, PDA tumor cells are surrounded by an extensive stroma, which accounts for up to 90% of the tumor volume. It is well recognized that stromal microenvironment can accelerate malignant transformation, tumor growth and progression. More importantly, the interaction loop between PDA and its stroma greatly contributes to tumor growth and progression. We propose that the extensive stroma of PDA is closely linked to its poor prognosis. An improved understanding of the mechanisms that contribute to pancreatic tumor growth and progression is therefore urgently needed. Targeting the stroma may thus provide novel prevention, earlier detection and therapeutic options to this deadly malignancy. Accordingly, in this review, we will summarize the mechanism of PDA stroma formation, the role of the stroma in tumor progression and therapy resistance and the potential of stroma-targeted therapeutics strategies.

Grape-seed procyanidins inhibit the in vitro growth and invasion of pancreatic carcinoma cells

OBJECTIVES

Grape-seed procyanidins (GSPs) can inhibit cell proliferation and invasiveness in various human cancers. However, the effect of GSP on pancreatic carcinoma cells has not been investigated.

METHODS

Pancreatic carcinoma cell lines MIA PaCa-2 and BxPC-3 treated with GSP were assessed for viability by trypan blue exclusion, for cell cycle distribution by flow cytometry, for increased apoptosis by annexin V labeling, for their adhesion and invasion potential by evaluating their ability to penetrate through a matrix gel-coated Boyden chamber, and for changes in the levels of proteins involved in cellular events by immunoblotting.

RESULTS

Grape-seed procyanidin inhibited MIA PaCa-2 and BxPC-3 proliferation in a dose-dependent manner and induced G1-phase arrest of the cell cycle in BxPC-3 or mitochondria-mediated apoptosis in MIA PaCa-2. Grape-seed procyanidin also inhibited the adhesion and invasion potential of both cell lines in a dose-dependent manner, which are associated with the suppression of metalloproteases matrix metalloproteinase 9 or 2 (MMP-9 or -2) expression.

CONCLUSIONS

Grape-seed procyanidin inhibited the proliferation of pancreatic carcinoma cells by cell cycle blockage or apoptotic induction. The invasiveness was also suppressed by GSP through down-regulation of MMP-2 or MMP-9 in pancreatic carcinoma cells. Grape-seed procyanidin is a potential chemotherapeutic or preventive agent for pancreatic carcinoma.

Keratinocyte growth factor induces matrix metalloproteinase-9 expression and correlates with venous invasion in pancreatic cancer

Keratinocyte growth factor (KGF), also known as fibroblast growth factor-7, and KGF receptor (KGFR) play important roles in the growth of epithelial cells and are overexpressed in a variety of malignant epithelial tumors, including pancreatic ductal adenocarcinoma (PDAC). We previously reported that co-expression of KGF and KGFR in PDAC is associated with venous invasion, enhanced vascular endothelial growth factor A expression and poor prognosis. Matrix metalloproteinase-9 (MMP-9) is known to participate in the degradation of type IV collagen, which is a primary component of extracellular matrices in the vascular basement membrane. In the present study, we examined the expression and roles of KGF, KGFR and MMP-9 in human PDAC cell lines and tissues. Quantitative real-time polymerase chain reaction analysis demonstrated the expression of MMP-9 mRNA in all eight PDAC cell lines. KGF, KGFR and MMP-9 were, respectively, expressed in 27 (43%), 23 (37%) and 35 (56%) of 63 patients. Each expression of KGF, KGFR or MMP-9 correlated positively with venous invasion. Furthermore, expression of KGF or MMP-9 correlated positively with liver metastasis. KGF-positive cases exhibited shorter survival than KGF-negative cases, while KGFR and MMP-9 expression were unrelated to prognosis. Administration of recombinant human KGF increased MMP-9 expression in PDAC cells, while transient transfection with short hairpin RNAs targeting KGF transcripts reduced MMP-9 expression in PDAC cells. Moreover, recombinant human KGF significantly enhanced migration and invasion of PDAC cells. These findings suggest that KGF and KGFR promote venous invasion via MMP-9 in PDAC, and closely correlate with liver metastasis. The KGF/KGFR pathway may be a critical therapeutic target for PDAC metastasis.

Serum biomarker panels for the detection of pancreatic cancer

PURPOSE

Serum-biomarker based screening for pancreatic cancer could greatly improve survival in appropriately targeted high-risk populations.

EXPERIMENTAL DESIGN

Eighty-three circulating proteins were analyzed in sera of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC, n = 333), benign pancreatic conditions (n = 144), and healthy control individuals (n = 227). Samples from each group were split randomly into training and blinded validation sets prior to analysis. A Metropolis algorithm with Monte Carlo simulation (MMC) was used to identify discriminatory biomarker panels in the training set. Identified panels were evaluated in the validation set and in patients diagnosed with colon (n = 33), lung (n = 62), and breast (n = 108) cancers.

RESULTS

Several robust profiles of protein alterations were present in sera of PDAC patients compared to the Healthy and Benign groups. In the training set (n = 160 PDAC, 74 Benign, 107 Healthy), the panel of CA 19-9, ICAM-1, and OPG discriminated PDAC patients from Healthy controls with a sensitivity/specificity (SN/SP) of 88/90%, while the panel of CA 19-9, CEA, and TIMP-1 discriminated PDAC patients from Benign subjects with an SN/SP of 76/90%. In an independent validation set (n = 173 PDAC, 70 Benign, 120 Healthy), the panel of CA 19-9, ICAM-1 and OPG demonstrated an SN/SP of 78/94% while the panel of CA19-9, CEA, and TIMP-1 demonstrated an SN/SP of 71/89%. The CA19-9, ICAM-1, OPG panel is selective for PDAC and does not recognize breast (SP = 100%), lung (SP = 97%), or colon (SP = 97%) cancer.

CONCLUSIONS

The PDAC-specific biomarker panels identified in this investigation warrant additional clinical validation to determine their role in screening targeted high-risk populations.

X-ray irradiation and Rho-kinase inhibitor additively induce invasiveness of the cells of the pancreatic cancer line, MIAPaCa-2, which exhibits mesenchymal and amoeboid motility

Tumor cells can migrate and invade tissue by two modes of motility: mesenchymal and amoeboid. X-ray or γ-ray irradiation increases the invasiveness of tumor cells with mesenchymal motility through the induction of matrix metalloproteinases (MMP), and this increase is suppressed by MMP inhibitors (MMPI). However, the effects of X-ray or γ-ray irradiation on the invasiveness of tumor cells with amoeboid motility remain unclear. We investigated the effect of irradiation on amoeboid motility by using cells of the human pancreatic cancer line, MIAPaCa-2, which exhibits both modes of motility. The X-ray-induced invasiveness of MIAPaCa-2 cells was associated with the upregulation of MMP2 at both the RNA and protein levels and was inhibited by MMPI treatment. Amoeboid-mesenchymal transition was slightly induced after irradiation. The MMPI treatment caused mesenchymal-amoeboid transition without significant increase in invasiveness, while the ROCK inhibitor (ROCKI) stimulated amoeboid-mesenchymal transition and enhanced invasiveness under both non-irradiated and irradiated conditions. This ROCKI-induced transition was accompanied by the upregulation of MMP2 mRNA and protein. Exposure to both irradiation and ROCKI further enhanced MMP2 expression and had an additive effect on the invasiveness of MIAPaCa-2 cells. Additionally, exposure to MMPI led to significant suppression of both radiation-induced and the basal invasiveness of MIAPaCa-2 cells. This suggests that ROCKI treatment, especially with concomitant X-ray irradiation, can induce invasion of cancer cells and should be used only for certain types of cancer cells. Simultaneous use of inhibitors, ROCKI and MMPI may be effective in suppressing invasiveness under both X-ray-irradiated and non-irradiated conditions.

GSK3beta and beta-catenin modulate radiation cytotoxicity in pancreatic cancer

BACKGROUND

Knowledge of factors and mechanisms contributing to the inherent radioresistance of pancreatic cancer may improve cancer treatment. Irradiation inhibits glycogen synthase kinase 3beta (GSK3beta) by phosphorylation at serine 9. In turn, release of cytosolic membrane beta-catenin with subsequent nuclear translocation promotes survival. Both GSK3beta and beta-catenin have been implicated in cancer cell proliferation and resistance to death.

METHODS

We investigated pancreatic cancer cell survival after radiation in vitro and in vivo, with a particular focus on the role of the function of the GSK3beta/beta-catenin axis.

RESULTS

Lithium chloride, RNAi-medicated silencing of GSK3beta, or the expression of a kinase dead mutant GSK3beta resulted in radioresistance of Panc1 and BxPC3 pancreatic cancer cells. Conversely, ectopic expression of a constitutively active form of GSK3beta resulted in radiosensitization of Panc1 cells. GSK3beta silencing increased radiation-induced beta-catenin target gene expression as measured by studies of AXIN2 and LEF1 transcript levels. Western blot analysis of total and phosphorylated levels of GSK3beta and beta-catenin showed that GSK3beta inhibition resulted in stabilization of beta-catenin. Xenografts of both BxPC3 and Panc1 with targeted silencing of GSK3beta exhibited radioresistance in vivo. Silencing of beta-catenin resulted in radiosensitization, whereas a nondegradable beta-catenin construct induced radioresistance.

CONCLUSIONS

These data support the hypothesis that GSK3beta modulates the cellular response to radiation in a beta-catenin-dependent mechanism. Further understanding of this pathway may enhance the development of clinical trials combining drugs inhibiting beta-catenin activation with radiation and chemotherapy in locally advanced pancreatic cancer.

The pathogenesis of tendinopathy: balancing the response to loading

Tendons are designed to withstand considerable loads. Mechanical loading of tendon tissue results in upregulation of collagen expression and increased synthesis of collagen protein, the extent of which is probably regulated by the strain experienced by the resident fibroblasts (tenocytes). This increase in collagen formation peaks around 24 h after exercise and remains elevated for about 3 days. The degradation of collagen proteins also rises after exercise, but seems to peak earlier than the synthesis. Despite the ability of tendons to adapt to loading, repetitive use often results in injuries, such as tendinopathy, which is characterized by pain during activity, localized tenderness upon palpation, swelling and impaired performance. Tendon histological changes include reduced numbers and rounding of fibroblasts, increased content of proteoglycans, glycosaminoglycans and water, hypervascularization and disorganized collagen fibrils. At the molecular level, the levels of messenger RNA for type I and III collagens, proteoglycans, angiogenic factors, stress and regenerative proteins and proteolytic enzymes are increased. Tendon microrupture and material fatigue have been suggested as possible injury mechanisms, thus implying that one or more 'weak links' are present in the structure. Understanding how tendon tissue adapts to mechanical loading will help to unravel the pathogenesis of tendinopathy.

Chemoprevention by Pyrimethamine

The goal of the current research was to investigate the chemopreventive potency of an antimalaria drug, pyrimethamine, in in vitro conditions. The fibrosarcoma (WEHI-164) cell line was used for evaluating cytotoxicity, matrix metalloproteinase 2 (MMP-2) activity, and apoptosis. Pyrimethamine and methotrexate were used at concentrations of 0-8 microg/ml in triplicate and 2-fold dilutions. MMP-2 activity was assessed using zymoanalysis method. For assessment of apoptosis, the terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method was used. Cytotoxicity analysis of pyrimethamine showed a greater tolerability than methotrexate at concentrations of 1-8 microg/ml. The dose-dependent inhibitory effect of pyrimethamine on MMP-2 activity was significantly less than that of methotrexate at concentrations of 1-8 microg/ml. Moreover, the rate of apoptosis for pyrimethamine-treated cells at different doses (0.1, 1, and 10 microg/ml) was 3.30%, 9.42%, and 11.32%, respectively. Our data suggest that pyrimethamine enables suppression of MMP-2 activity and induces apoptosis that could be assumed for chemoprevention therapy.

Bee Venom, Immunostimulant or Immunosuppressor? Insight into the Effect on Matrix Metalloproteinases and Interferons

The current evidence has defined conflicting properties for bee venom. The goal of this study was to determine whether bee venom (BV) is an immunosuppressor or immunostimulant. The WEHI-164, HT-1080, and K562 cell lines were used for assaying toxicity, proliferative response, matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) activity, and interferon production. The Australian and Iranian BV (ABV and IBV) were used at concentrations of 0.025-1 microg/ml in triplicate and 2-fold dilutions. MMP-2 and -9 activities were evaluated using the zymography method. The production of interferons (IFN-alpha and IFN-beta) were assessed using enzyme-linked immunoassay procedure. Our results show no significant difference between two sources of honeybee venom (ABV and IBV) when they are added to an identified cell line, whereas the response of various cell lines against BV could be different. The increasing amounts of ABV and/or IBV (between doses 0.025-0.5 microg/ml) to human monocyte cell line (K562) exhibit a significant increase in proliferative response. Our data show that the immunomodulatory effect of ABV and/or IBV on MMP-2 and MMP-9 activity in both cell culture media, WEHI-164 and K562, is similar. The stimulatory effect of BV on MMP-2 and -9 activities is occurred between doses 0-0.05 microg/ ml. In contrast, the inhibitory effect of BV on these two MMPs is seen at concentrations of >0.05 microg/ml. The ABV and/or IBV has no influence on IFN-alpha production in cell culture media, whereas adding the BV to K562 cell line could significantly increase the production level of IFN-beta only on day 8 posttreatment. We conclude that time- and dose-dependent response as well as the type of treated cell line could determine the immunosuppressive and/or immunostimulant property of bee venom that could be effective in future therapeutic strategies.

Chondrocyte phenotype and ectopic ossification in collagenase-induced tendon degeneration

We report chondrocyte phenotype and ectopic ossification in a collagenase-induced patellar tendon injury model. Collagenase or saline was injected intratendinously in one limb. The patella tendon was harvested for assessment at different times. There was an increase in cellularity, vascularity, and loss of matrix organization with time after collagenase injection. The tendon did not heal histologically until week 32. Ectopic mineralization as indicated by von Kossa staining started from week 8. Tendon calcification was mediated by endochondral ossification, as shown by expression of type X collagen. viva CT imaging and polarization microscopy showed characteristic bony porous structures and collagen fiber arrangement, respectively, in the calcific regions. Marrow-like cells and blood vessels were observed inside calcific deposits. Chondrocyte-like cells as indicated by morphology, expression of type II collagen, and sox 9 were seen around and embedded inside the calcific deposits. Fibroblast-like cells expressed type II collagen and sox 9 at earlier times, suggesting that erroneous differentiation of healing tendon fibroblasts may account for failed healing and ossification in collagenase-induced tendon degeneration. Because this animal model replicates key histopathological changes in calcific tendinopathy, it can be used as a model for the study of its pathogenesis at the patellar tendon.

Proteomic analysis identifies MMP-9, DJ-1 and A1BG as overexpressed proteins in pancreatic juice from pancreatic ductal adenocarcinoma patients

Background

There is an urgent need to discover more sensitive and specific biomarkers to improve early diagnosis and screen high-risk patients for pancreatic ductal adenocarcinoma (PDAC). Pancreatic juice is an ideal specimen for PDAC biomarkers discovery, because it is an exceptionally rich source of proteins released from pancreatic cancer cells.

Methods

To identify novel potential biomarkers for PDAC from pancreatic juice, we carried out difference gel electrophoresis (DIGE) and tandem mass spectrometry (MS/MS) to compare the pancreatic juice profiling from 9 PDAC patients and 9 cancer-free controls. Of the identified differently expressed proteins, three up-regulated proteins in pancreatic cancer juice, matrix metalloproteinase-9 (MMP-9), oncogene DJ1 (DJ-1) and alpha-1B-glycoprotein precursor (A1BG), were selected for validation by Western blot and immunohistochemistry. Serum MMP-9 levels were also detected by enzyme linked immunosorbent assay (ELISA).

Results

Fourteen proteins were up-regulated and ten proteins were down-regulated in cancerous pancreatic juice compared with cancer-free controls. Increased MMP-9, DJ-1 and A1BG expression in cancerous pancreatic juice were confirmed by Western blot. Immunohistochemical study showed MMP-9, DJ-1 and A1BG positively expressed in 82.4%, 72.5% and 86.3% of pancreatic cancer tissues, significantly higher than that in normal pancreas tissues. Up-regulation of DJ-1 was associated with better differentiation (p < 0.05). Serum MMP-9 levels were significantly higher in PDAC (255.14 ng/ml) than those in chronic pancreatitis (210.22 ng/ml, p = 0.009) and healthy control (203.77 ng/ml, p = 0.027).

Conclusion

The present proteome analysis revealed MMP-9, DJ-1 and A1BG proteins as elevated in pancreatic juice from PDAC, which suggest their further utility in PDAC diagnosis and screening. This is the first time A1BG was identified as a potential biomarker in pancreatic cancer associated samples. The measurement of serum MMP-9 might be clinically useful for PDAC diagnosis.

Inhibitory effect of aerial parts of Scrophularia striata on matrix metalloproteinases expression

It has been shown that destruction of the extracellular matrix (ECM) by matrix metalloproteinases (MMPs) leads to tumor invasion, metastasis and angiogenesis. The aim of the present research was to verify the effects of a total extract and sequential extracts of Scrophularia striata Boiss (Scrophulariaceae) on MMPs activity. The fibro sarcoma cell line (wehi-164) was used to assess MMPs inhibitory effect. The MMPs activity was evaluated using a zymoanalysis method. The results of this study showed that the highest MMPs inhibitory effect (55.6%) was observed after treatment with 10 microg/mL of the high polarity methanol solution extract corresponding to its lowest cytotoxicity effect (4%). It is concluded that the aerial parts of S. striata might contain various polar compounds that inhibit MMPs.

Expression of matrix metalloproteinase-7 on cancer cells and tissue endothelial cells in renal cell carcinoma: prognostic implications and clinical significance for invasion and metastasis

PURPOSE

The expression of matrix metalloproteinase-7 (MMP-7) correlates with the malignant potential of various tumors and patient survival. We investigated the clinical and prognostic significance of MMP-7 expression in cancer cells and endothelial cells in human renal cell carcinoma (RCC).

EXPERIMENTAL DESIGN

We reviewed tissue samples of 156 patients with RCC who had undergone radical operation. MMP-7 expression was examined by immunohistochemistry. Sections containing MMP-7-positive vessels were also stained for CD34. The density of MMP-7-positive vessels was determined by a computer-aided image analysis system. Multivariate analysis was done to assess relevant variables for invasion, metastasis, and cause-specific survival.

RESULTS

The proportion of MMP-7-expressing tumor cells were significantly higher (P < 0.001) than that of normal cells. MMP-7-positive vessels were considered blood vessels based on staining for CD34, and their density was increased in tumor areas. The proportion of MMP-7-expressing cancer cells and density of MMP-7-positive vessels correlated with grade, pathologic tumor stage, and metastasis. Multivariate analysis showed that MMP-7 expression on cancer cells correlated with pathologic tumor stage only, whereas MMP-7-positive vessel density correlated with metastasis only. The elevated status of MMP-7 in cancer tissues was an independent predictor for cause-specific survival (odds ratio, 8.61; P = 0.040) by multivariate analysis.

CONCLUSIONS

Our results showed that MMP-7 influences tumor progression by regulating invasion and angiogenesis. Multivariate analysis showed that MMP-7 status of cancer tissues was strong predictor of poor prognosis. Our results suggest that MMP-7 targeting treatment may be a potential target against RCC.

Cell phenotypic variation in normal and damaged tendons

Injuries to tendons are common in both human athletes as well as in animals, such as the horse, which are used for competitive purposes. Furthermore, such injuries are also increasing in prevalence in the ageing, sedentary population. Tendon diseases often respond poorly to treatment and require lengthy periods of rehabilitation. The tendon has a unique extracellular matrix, which has developed to withstand the mechanical demands of such tensile-load bearing structures. Following injury, any repair process is inadequate and results in tissue that is distinct from original tendon tissue. There is growing evidence for the key role of the tendon cell (tenocyte) in both the normal physiological homeostasis and regulation of the tendon matrix and the pathological derangements that occur in disease. In particular, the tenocyte is considered to have a major role in effecting the subclinical matrix degeneration that is thought to occur prior to clinical disease, as well as in the severe degradative events that occur in the tendon at the onset of clinical disease. Furthermore, the tenocyte is likely to have a central role in the production of the biologically inadequate fibrocartilaginous repair tissue that develops subsequent to tendinopathy. Understanding the biology of the tenocyte is central to the development of appropriate interventions and drug therapies that will either prevent the onset of disease, or lead to more rapid and appropriate repair of injured tendon. Central to this is a full understanding of the proteolytic response in the tendon in disease by such enzymes as metalloproteinases, as well as the control of the inappropriate fibrocartilaginous differentiation. Finally, it is important that we understand the role of both intrinsic and extrinsic cellular elements in the repair process in the tendon subsequent to injury.

Expression of Matrix Metalloproteinase-10 in Renal Cell Carcinoma and Its Prognostic Role

OBJECTIVES

Matrix metalloproteinase (MMP)-10 is associated with malignant aggressiveness in various cancers, but its importance has not been investigated in conventional renal cell carcinoma (CRCC). The purpose of this study was to determine the clinical significance and malignant potential of MMP-10 in human CRCC tissues.

PATIENTS AND METHODS

Specimens were obtained from 103 CRCC patients who underwent radical surgery and were examined by immunohistochemistry for MMP-10 expression. The proportions of Ki-67-stained cells (proliferation index: PI) and densities of CD34-positive vessels (microvessel density: MVD) were measured by a computer-aided image analysis system. The relationships between MMP-10 expression and clinicopathologic features and various parameters including tumour size, PI, MVD, and survival were investigated by univariate and multivariate analyses.

RESULTS

MMP-10 expression was mainly detected in cancer cell cytoplasm, and 45 (43.7%) CRCCs were considered MMP-10-positive. MMP-10 expression correlated with grade (p=0.006) and pT stage (p<0.001), and it was a significant and independent factor for high pT stage in multivariate analysis model. MMP-10 expression was associated with MVD (p = 0.022) but not tumour size or PI. MMP-10 expression in CRCC was a significant predictor of poor outcome by log-rank test (p = 0.013) but not by multivariate analysis.

CONCLUSIONS

MMP-10 seems to play an important role in renal cancer cell invasion and is a potentially useful therapeutic target to prevent CRCC tumour progression.

Future strategies for targeted therapies and tailored patient management in pancreatic cancer

Pancreatic cancer represents the fourth leading cause of cancer-related mortality in the United States. The vast majority of patients are diagnosed at advanced stages of the disease, at which time gemcitabine-based chemotherapy is typically offered as the standard of care. However, as investigators have arrived at a greater understanding of pancreatic tumor biology, newer therapeutic agents that "target" specific pathways or molecules governing the growth, spread, and maintenance of tumor cells have gained considerable interest. Erlotinib, an orally bioavailable small molecule inhibitor of the epidermal growth factor receptor, is the first of these targeted compounds to be approved for use in combination with gemcitabine for patients with advanced pancreatic cancer. Other targeted agents, including monoclonal antibodies and small molecule inhibitors aimed at a variety of targets, also have been extensively evaluated, with limited success to date. A newer strategy worth pursuing involves tailoring an individual patient's therapy according to the molecular characteristics of both host and tumor, as has shown promise in other solid tumor types.

Inhibition of aggrecan turnover in short-term explant cultures of bovine tendon

The large aggregating proteoglycan, aggrecan, better known for its physiological role in articular cartilage where it serves to facilitate resistance of compressive forces during joint articulation, is also present within the distinct functional regions of tendon (i.e., compressed/fibrocartilaginous and tensional). Previous studies demonstrate that an increased turnover of aggrecan occurs in tendon, which is mediated principally by the 'aggrecanases' and, as such, these proteinases may play an important role in the normal functioning of the tissue. In the present study, utilising bovine tendon explant culture systems, we demonstrated that aggrecanase-mediated tendon aggrecan turnover may be modulated by generic metalloproteinase inhibitors (i.e., the aggrecanase inhibitor, actinonin and the broad-spectrum MMP inhibitor, marimistat). As expected, no MMP-generated aggrecan catabolites were detected in the culture system, suggesting that tendon aggrecanases may be inhibited by marimistat. Furthermore, immunohistochemical analyses revealed that aggrecan metabolites are present in the endotenon, surrounding the collagen fibre bundles, suggesting that aggrecan may provide functions of water imbibement and resistance of reversible and repeated compressive loads manifest between the collagen fibres; these functions, in turn, may be associated with increased aggrecan turnover in this tissue. Thus, inhibition of tendon aggrecanases and consequently aggrecan turnover in this tissue, may be related to some of the deleterious effects observed in the tendons of patients undergoing drug therapy with broad-spectrum MMP inhibitors for cancer and arthritis.

Two matrix metalloproteinases inhibitors from Ferula persica var. persica

Matrix metalloproteinases (MMPs) play a role in several physiologic and pathologic events. There is some evidence indicating the involvement of MMPs in tumor invasion and inflammatory diseases. Here we studied the chloroform extract of Ferula persica var. persica. The influence of these extracts vs. a reference drug, diclofenac sodium, on MMP production by the fibrosarcoma cell line was investigated using an in vitro cytotoxicity assay, sodium dodecyl sulfate-polyacrylamide, and gelatin zymography. The total extract of the roots was found to exhibit a selective inhibitory effect on tumor cell invasion. The bioactivity-guided fractionation of this extract led to the isolation of two compounds. These compounds showed highest MMP inhibitory effect at minimal toxic dose levels. Using conventional spectroscopy methods, the active fractions were identified as t-butyl 3-[(1-methylthiopropyl)dithio]-2-propenyl malonate (persicasulphide B) and umbelliprenin, previously isolated from F. persica var. latisecta. Since inhibition of MMP activity has been employed in modality therapy in diseases such as cancer, this compound might be promising in the preparation of anti-MMP therapeutic derivatives.

Inhibitory effect of acetylsalicylic acid on matrix metalloproteinase - 2 activity in human endothelial cells exposed to high glucose

Matrix metalloproteinases play a major role in the process of angiogenesis, an important feature of diabetes complications, cancer or rheumatoid arthritis. High glucose concentrations were reported to augment metalloproteinase-2 secretion in some cell types. In the present study we investigated the influence of acetylsalicylic acid on metalloproteinase- 2 secretion and expression in endothelial cells cultured for one week in high glucose conditions (25 mM and 33 mM). Metalloproteinase-2 activity was evidenced by gel zymography, the protein was identified by Western blotting, and the gene expression was quantitated by RT-PCR. The results indicated a marked inhibitory effect of acetylsalicylic acid at gene expression level (approximately 43%) and also at secretion level in samples of conditioned media (approximately 30%) and cellular homogenates (approximately 70%). This may suggest that acetylsalicylic acid could have a beneficial effect in preventing the angiogenic process that appears in diabetes complications.

Molecular prognostic markers in pancreatic cancer: a systematic review

Pancreatic cancer is one of the most lethal tumours of the gastrointestinal tract. The ability to predict which patients would benefit most from surgical intervention and/or chemotherapy would be a great clinical asset. Considerable research has focused on identifying molecular events in pancreatic carcinogenesis, and their correlation with clinicopathological variables of pancreatic tumours and survival. This systematic review examined evidence from published manuscripts looking at molecular markers in pancreatic cancer and their correlation with tumour stage and grade, response to chemotherapy and long-term survival. A literature search was undertaken using PubMed and MEDLINE search engines, using the keywords p53, p21, p16, p27, SMAD4, K-ras, cyclin D1, Bax, Bcl-2, EGFR, EGF, c-erbB2, HB-EGF, TGFbeta, FGF, MMP, uPA, cathepsin, heparanase, E-cadherin, laminins, integrins, TMSF, CD44, cytokines, angiogenesis, VEGF, IL-8, beta-catenin, DNA microarray, and gene profiling. A bewildering number of biomarkers are currently under evaluation. For the most part, the evidence regarding their application as prognostic indicators is conflicting. The advent of gene microarray and mass spectrometric protein profiling offers the potential to examine many different biomarkers simultaneously. This 'protein/gene signature' could revolutionise work in this field and allow researchers to develop accurate and reproducible predictions of survival based on protein or gene profiles.

Macrophage inflammatory protein-3alpha promotes pancreatic cancer cell invasion

BACKGROUND

Human CC chemokine Macrophage Inflammatory Protein-3alpha (MIP-3alpha) directs inflammatory cell migration through its binding to the transmembrane receptor CCR6. MIP-3alpha has recently been shown to promote tumor cell migration in pancreatic adenocarcinoma by up-regulation of matrix metalloproteinases (MMPs). We hypothesized that MIP-3alpha promotes pancreatic cancer invasion through the up-regulation of MMP-9, a Type 4 collagenase.

MATERIALS, METHODS, AND RESULTS

Immunohistochemistry and RT-PCR confirmed the presence of MIP-3alpha in PANC-1 cells, a human pancreatic adenocarcinoma cell line. MIP-3alpha stimulated the production of both latent and active forms of MMP-9 in PANC-1 by Western analysis. Tumor cell invasion was then evaluated using a modified Boyden chamber invasion assay. MIP-3alpha promoted a dose-dependent increase in pancreatic cancer cell invasion (P < 0.05) at 100 ng/ml. The activity at the putative MIP-3alpha receptor, CCR6, was demonstrated by receptor blockade. Anti-CCR6 antibody and anti-MMP-9 antibody inhibited MIP-3alpha-stimulated PANC-1 cell invasion of collagen to 37% and 35% of control, respectively (P < 0.05).

CONCLUSIONS

MIP-3alpha, through its CCR6 receptor, promotes tumor cell invasion by the up-regulation of MMP-9. Molecular based therapy aimed at the inhibition of MIP-3alpha activity through the CCR6 receptor may serve as a future target to prevent tumor cell invasion in pancreatic adenocarcinoma.

Role of Proteases in Pancreatic Carcinoma

Proteases play an important role in cancer invasion and metastasis. In this review we specifically discuss the role of these proteases in pancreatic carcinoma. Serine proteases and matrix metalloproteinases are the focus of intense research, as they appear to be related to the process of tumor progression. We discuss the diagnostic and prognostic value of these two groups of proteases. Lastly, we report on the current and recent clinical trials focusing on inhibition of these proteases.

Predictive value of lymph node and tumor matrix metalloproteinase expression in the analysis of metastatic periampullary tumors

BACKGROUND AND OBJECTIVES

Matrix metalloproteinases (MMP) are endogenous peptidases capable of degrading various components of the basement membrane. The ability of malignant epithelial cells to degrade extracellular matrix and basement membrane is an important step in the process of metastatic invasion. In this study, we prospectively compared the outcome of patients undergoing laparotomy for resection of periampullary malignancies with lymph node and tumor MMP expression to determine if there was a correlation between metalloproteinase expression and patient outcome.

METHODS

Sixteen patients undergoing operation were followed prospectively. Expression of MMP-2 and -9 and their inhibitors TIMP (tissue inhibitor of matrix metalloproteinase) -1 and -2 were measured in lymph node and tumor samples by semiquantitative PCR analysis.

RESULTS

All patients who died from their disease process had significantly greater MMP-2 expression in their lymph nodes relative to TIMP-2 expression. In contrast, patients with prolonged disease-free survival had decreased nodal MMP-2/TIMP-2 expression (P = 0.001). Patients with relatively higher MMP-2/TIMP-2 expression in their tumors also had a worse prognosis (P = 0.06).

CONCLUSION

The data demonstrate that the mRNA expression of MMPs and TIMPs in the draining lymph node of patients with periampullary adenocarcinomas may hold prognostic significance for patient survival. This prognostic information may be of use in patients when planning future adjuvant therapies.

Comprehensive analysis of matrix metalloproteinase and tissue inhibitor expression in pancreatic cancer: increased expression of matrix metalloproteinase-7 predicts poor survival

PURPOSE

To enable the design of improved inhibitors of matrix metalloproteinases (MMPs) for the treatment of pancreatic cancer, the expression profiles of a range of MMPs and tissue inhibitors of MMPs (TIMPs) were determined.

EXPERIMENTAL DESIGN

Nine MMPs (MMPs 1-3, 7-9, 11, 12, and 14) and three TIMPs (TIMPs 1-3) were examined in up to 75 pancreatic ductal adenocarcinomas and 10 normal pancreata by immunohistochemistry. Eighteen additional pancreatic ductal adenocarcinomas and an additional eight normal pancreata were also analyzed by real-time reverse transcription-PCR and additionally for MMP-15.

RESULTS

There was increased expression by immunohistochemistry for MMPs 7, 8, 9, and 11 and TIMP-3 in pancreatic cancer compared with normal pancreas (P < 0.0001, 0.04, 0.0009, 0.005, and 0.0001, respectively). Real-time reverse transcription-PCR showed a significant increase in mRNA levels for MMP-11 in tumor tissue compared with normal pancreatic tissue (P = 0.0005) and also significantly reduced levels of MMP-15 (P = 0.0026). Univariate analysis revealed that survival was reduced by lymph node involvement (P = 0.0007) and increased expression of MMP-7 (P = 0.005) and (for the first time) MMP-11 (P = 0.02) but not reduced by tumor grade, tumor diameter, positive resection margins, adjuvant treatment, or expression of the remaining MMPs and TIMPs. On multivariate analysis, only MMP-7 predicted shortened survival (P < 0.05); however, increased MMP-11 expression was strongly associated with lymph node involvement (P = 0.0073).

CONCLUSIONS

We propose that the principle specificity for effective inhibitors of MMPs in pancreatic cancer should be for MMP-7 with secondary specificity against MMP-11. Moreover, these studies indicate that MMP-7 expression is a powerful independent prognostic indicator and potentially of considerable clinical value.

TIMPs as multifacial proteins

Tissue inhibitors of metalloproteinases (TIMPs) are natural inhibitors of matrix metalloproteinases (MMPs) found in most tissues and body fluids. By inhibiting MMPs activities, they participate in tissue remodeling of the extracellular matrix (ECM). The balance between MMPs and TIMPs activities is involved in both normal and pathological events such as wound healing, tissue remodeling, angiogenesis, invasion, tumorigenesis and metastasis. The intracellular signalling controlling both TIMPs and MMPs expression begins to be elucidated and gaining insights into the molecular mechanisms regulated by TIMPs and MMPs could represent a new approach in the development of potential therapeutics. Numerous investigations have pointed out that TIMPs exhibit multifunctional activities distinct from MMP inhibition. In this review, we detailed the multiple activities of TIMPs in vivo and in vitro and we reported their implication in physiological and pathological processes. Further, we documented recent studies of their role in hematopoiesis and we itemized the different signalling pathways they induced.

Adenoviral vectors expressing fusogenic membrane glycoproteins activated via matrix metalloproteinase cleavable linkers have significant antitumor potential in the gene therapy of gliomas

BACKGROUND

Fusogenic membrane glycoproteins (FMG) such as the gibbon ape leukemia virus envelope (GALV) glycoprotein are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. Transfection of glioma cell lines with FMG expression constructs results in fusion with massive syncytia formation followed by cytotoxic cell death. Nevertheless, ubiquitous expression of the GALV receptor, Pit-1, makes targeting desirable in order to increase the specificity of the observed cytopathic effect. Here we report on use of matrix metalloproteinase (MMP)-cleavable linkers to target the cytotoxicity of FMG-expressing adenoviral vectors against gliomas.

METHODS

Replication-defective adenoviruses (Ad) were constructed expressing the hyperfusogenic version of the GALV glycoprotein linked to a blocking ligand (C-terminal extracellular domain of CD40 ligand) through either an MMP-cleavable linker (AdM40) or a non-cleavable linker (AdN40). Both viruses also co-expressed the green fluorescent protein (GFP) via an internal ribosomal entry site.

RESULTS

The glioma cell lines U87, U118, and U251 characterized by zymography and MMP-2 activity assay as high, medium and low MMP expressors, respectively, the MMP-poor cell lines TE671 and normal human astrocytes were infected with AdM40 and AdN40 at different multiplicities of infection (MOIs) from 1-30. Fusion was quantitated by counting both number and size of syncytia. Infection of these cell lines with AdN40 did not result in fusion or cytotoxic cell death, despite the presence of infection, as demonstrated by GFP positivity, therefore indicating that the displayed CD40 ligand blocked GALV-induced fusion. Fusion was restored after infection of glioma cells with AdM40 at an MOI as low as 1 to an extent dependent on MMP expression and coxsackie adenovirus receptor (CAR) expression in the specific cell line. Western immunoblotting demonstrated the presence of the cleaved CD40 ligand in the supernatant of fused glioma cells. Use of the MMP inhibitors 1,10 phenanthroline and N-hydroxy-5,5-dimethylpiperazine-2-carboxamide completely abolished AdM40-induced fusion, while the non-specific serine protease inhibitor soybean trypsin inhibitor did not affect it, thus demonstrating specificity of the observed effect. Intratumoral treatment of BalbC/nude mice bearing subcutaneous U87 glioma xenografts with AdM40 at a total dose of 1.2 x 10(10) plaque-forming units (pfu) resulted in statistically significant tumor regression as compared with control animals either treated with AdN40 (p = 0.01) or untreated animals (p = 0.01). Treatment with AdM40 also resulted in survival improvement as compared with AdN40-treated animals (p = 0.006) or untreated animals (p = 0.001). Histopathologic examination of treated tumors demonstrated extensive syncytia formation.

CONCLUSIONS

Our data indicate that AdM40, a replication-defective adenovirus expressing the GALV fusogenic glycoprotein, attached to a blocking ligand via an MMP-cleavable linker, can target the cytotoxicity of GALV in MMP-overexpressing glioma lines and xenografts, and maintain significant antitumor activity both in vitro and in vivo. Given the high frequency of MMP overexpression in gliomas, AdM40 represents a potentially promising agent in the gene therapy of these tumors.

Comparison of gemcitabine versus the matrix metalloproteinase inhibitor BAY 12-9566 in patients with advanced or metastatic adenocarcinoma of the pancreas: a phase III trial of the National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To compare the selective matrix metalloproteinase inhibitor BAY 12-9566 with the nucleoside analog gemcitabine in the treatment of advanced pancreatic cancer.

METHODS

Patients with advanced pancreatic adenocarcinoma who had not previously received chemotherapy were randomly assigned to receive BAY 12-9566 800 mg orally bid continuously or gemcitabine 1,000 mg/m2 administered intravenously on days 1, 8, 15, 22, 29, 36, and 43 for the first 8 weeks, and then days 1, 8, and 15 of each subsequent 28-day cycle. The primary end point was overall survival; secondary end points were progression-free survival, tumor response, quality of life, and clinical benefit. The planned sample size of the study was 350 patients. Two formal interim analyses were planned.

RESULTS

The study was closed to accrual after the second interim analysis on the basis of the recommendation of the National Cancer Institute of Canada Clinical Trials Group Data Safety Monitoring Committee. There were 277 patients enrolled onto the study, 138 in the BAY 12-9566 arm and 139 in the gemcitabine arm. The rates of serious toxicity were low in both arms. The median survival for the BAY 12-9566 arm and the gemcitabine arm was 3.74 months and 6.59 months, respectively (P <.001; stratified log-rank test). The median progression-free survival for the BAY 12-9566 and gemcitabine arms was 1.68 and 3.5 months, respectively (P <.001). Quality-of-life analysis also favored gemcitabine.

CONCLUSION

Gemcitabine is significantly superior to BAY 12-9566 in advanced pancreatic cancer.

Targeting the cytotoxicity of fusogenic membrane glycoproteins in gliomas through protease-substrate interaction

Fusogenic membrane glycoproteins (FMG) are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. FMG expression constructs caused massive syncytia formation followed by cytotoxic cell death in glioma cell lines, and antitumor activity has been shown in glioma xenografts. FMG-induced fusion in glioma cells can involve heterologous cell lines including normal astrocytes and fibroblasts, therefore making targeting important. Here we report on the use of matrix metalloproteinase (MMP) cleavable linkers to target cytotoxicity of FMGs against gliomas. Expression constructs were made expressing the hyperfusogenic version of the Gibbon Ape Leukemia Virus envelope glycoprotein (GALV) linked to a blocking ligand (the C-terminal extracellular domain of CD40 ligand) via either an MMP cleavable linker (GALV M40), a factor Xa protease cleavable linker (GALV X40), or a noncleavable linker (GALV N40). Unmodified GALV expressing constructs were used as positive controls. The glioma cell lines U87, U118, and U251 previously characterized by zymography and MMP-2 activity assay as high, medium, and low MMP expressors, respectively; normal human astrocytes and the MMP-poor cell line TE671 were transfected with the GALV, GALV N40, GALV X40, and GALV M40 constructs. In contrast to unmodified GALV constructs, transfection with GALV X40 and GALV N40 constructs blocked fusion and cytotoxic cell death. Fusion occurred, however, after transfection with constructs containing MMP cleavable linkers to an extent dependent on MMP expression in the specific cell line. Use of the broad-spectrum MMP inhibitors, 1,10-phenanthroline and N-hydroxy-piperazine-carboxamide completely abolished the ability of MMP constructs to induce fusion. In cell mixing experiments, mixing of MMP-poor cell lines transfected with GALV M40 constructs with the MMP overexpressing untransfected U87 glioma cells led to partial restoration of fusion. Use of U87 supernatant did result in a similar effect. Establishment of stable tranfectants expressing the membrane-type MMPs, MT-1 MMP and MT-2 MMP did restore fusion in the MMP-poor cell line TE671 after transfection with GALV M40, thus indicating that both membrane-type MMPs and soluble MMPs activate the MMP cleavable constructs. In addition, the GALV M40 construct retained its cytotoxic activity against U87 cells in vivo, although less effectively as compared to unmodified GALV. Our data indicate that GALV-induced cytotoxicity in glioma cell lines can be blocked by display of the CD40 ligand. Incorporation of an MMP cleavable linker can selectively restore cytotoxicity in MMP expressing glioma cell lines both in vitro and in vivo, while sparing normal human astrocytes. Given the high frequency of MMP overexpression in gliomas, this represents a promising targeting strategy.

Evaluation of vascular endothelial growth factor blockade and matrix metalloproteinase inhibition as a combination therapy for experimental human pancreatic cancer

Blockade of vascular endothelial growth factor (VEGF) and inhibition of matrix metalloproteinases (MMP) are promising therapies for cancer. This study assessed the effects of a neutralizing anti-VEGF antibody (A4.6.1) and an MMP inhibitor (BB-94) on pancreatic cancer (PaCa) in vivo. Five million cells of two human PaCa cell lines (AsPC-1 and HPAF-2) were injected subcutaneously into nude mice; 1 mm(3) fragments of the resulting tumors were implanted into the pancreas of other mice. Animals were randomized into a control group and three treatment groups: A4.6.1 (100 microg intraperitoneally twice weekly); BB-94 (50 mg/kg every other day); and combination (A4.6.1 plus BB-94). Treatment was started after 3 days and continued for 14 weeks. Tumor volume, local and distant spread (score), and ascites were determined at autopsy. Microvessel density as a parameter of neoangiogenesis was analyzed in CD31-stained tumor sections. Both monotherapies reduced tumor volume (HPAF-2: -89% by A4.6.1 and -75% by BB-94; AsPC-1: -48% by A4.6.1 and -72% by BB-94), spread (HPAF-2: -76% by A4.6.1 and -58% by BB-94; AsPC-1: -32% by A4.6.1 and -54% by BB-94), and microvessel density (HPAF-2: -75% by A4.6.1 and -30% by BB-94; AsPC-1: -59% by A4.6.1 and -30% by BB-94), resulting in a tendency toward increased survival (HPAF-2: 8 of 8 animals by A4.6.1 or BB-94 vs. 4 of 8; AsPC-1: 3 of 8 by A4.6.1, 4 of 8 by BB-94 vs. 1 of 8). Combination therapy yielded additional effects in the HPAF-2 group with regard to tumor volume (-95%) and development of ascites (0 of 8 vs. 2 of 8 by A4.6.1 or BB-94 vs. 5 of 8 control mice). Both VEGF blockade and MMP inhibition reduce primary tumor size, metastasis, and angiogenesis, thereby increasing survival in experimental pancreatic cancer. Combination treatment results in additive effects in moderately differentiated HPAF-2 tumors.

Expression and prognostic significance of matrix metalloproteinases and their tissue inhibitors in primary neuroendocrine carcinoma of the skin

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been implicated in the development and progression of many tumors, but data for primary neuroendocrine carcinoma (PNC) of the skin are lacking. The aim of the study was to assess the expression of MMPs and TIMPs in PNC and to evaluate their prognostic significance. Expression of MMP-1, MMP-2, MMP-3, MMP-9, MMP-11, MMP-13, and MMP-14 and TIMP-1, TIMP-2, and TIMP-3 was evaluated by immunohistochemistry on 23 samples of PNC of the skin. The results were matched with clinical features and patient survival. In the 23 specimens of PNC, high (>20% of positive neoplastic cells) MMP-1 expression was found in 13 (56.5%) cases. MMP-2 was evidenced in 12 (52.1%) cases, 8 (34.7%) of which showed high expression in neoplastic cells. MMP-3 was detected in 11 cases (47.8%), with high expression in 9 (39.1%) of them. High MMP-9 expression was observed in 3 (13%) cases, whereas high MMP-14 expression was detected in 11 (47.8%) specimens. Expression of TIMP-1 by neoplastic cells was found in 8 (34.7%) cases, with high expression in 3 cases, whereas high TIMP-3 expression was detected in 21 (91.3%) cases. No immunoreactivity for MMP-11, MMP-13, or TIMP-2 was found. Statistical analysis failed to identify a significant correlation between MMP/TIMP expression and clinical parameters. By univariate analysis, stage >I (P = 0.01), high expression of MMP-1 (P = 0.04) and MMP-3 (P = 0.01) resulted significant negative prognostic factors, whereas by multivariate analysis, stage was the only factor that affected survival (P = 0.02). Our results suggest that MMP-1 and MMP-3 may influence the invasive and metastatic potential of PNCs. It is conceivable that future attempts to specifically block MMP-1 and MMP-3 activity may provide a novel means to inhibit invasiveness and distant spread in selected patients with PNC.

Anti-invasive and metastatic activities of evodiamine

We have recently reported that evodiamine can suppress in vitro invasion and lung metastasis by colon 26-L5 carcinoma cells. To extend our study, we examine here the anti-invasive and metastatic effects of evodiamine on Lewis lung carcinoma (LLC) and B16-F10 melanoma in addition to colon 26-L5 carcinoma. Critical structures of evodiamine for the activities were also evaluated by comparison with compounds possessing structures similar to that of evodiamine. Evodiamine concentration-dependently inhibited the invasion of B16-F10, LLC and colon 26-L5 cells with IC(50) values of 2.4 micro M, 4.8 micro M and 3.7 micro M, respectively. Pre-treatment of colon 26-L5 cells with evodiamine before inoculation into mice caused significant suppression of the liver metastasis as well as the lung metastasis. Lung metastasis by LLC is also inhibited significantly by pre-exposure to evodiamine. When the anti-migratory activity of evodiamine was compared with that of evodiamine-like compounds, rutaecarpine lacking a methyl group at N-14 and a hydrogen at C-13 b exhibited much less effect than evodiamine. In addition, reserpine, having beta-configurated hydrogen at C-13 b, inhibited tumor cell migration more potently than yohimbine, having alpha-configurated hydrogen at the same position. These results suggest that evodiamine may be useful as a leading compound for agents in tumor metastasis therapy. Also, the presence of a methyl group at N-14 and the configuration of hydrogen at C-13 b may be responsible for the inhibitory activities of evodiamine.

Matrix metalloproteinases and their role in pancreatic cancer: a review of preclinical studies and clinical trials

Matrix metalloproteinases (MMPs) have received much attention in recent years for their role in a variety of malignancies. Pancreatic cancer is no exception; MMP-2 and MMP-9 show high levels of expression in clinical and experimental models. Inhibition of MMPs has shown great promise with synthetic inhibitors, such as BB-94, as tumorostatic agents in preclinical models, particularly when these are combined with gemcitabine. These findings have led to several clinical trials using the MMP inhibitors Marimastat and BAY12-9566. Herein, we discuss the roles of MMPs and their inhibition in pancreatic cancer.

Perioperative matrix metalloproteinase inhibition therapy does not impair wound or anastomotic healing

Matrix metalloproteinases (MMPs) catalyze the degradation of collagen and extracellular matrix. They play a role in pathologic states including malignancy, in which they facilitate invasion and metastasis. MMP inhibition has been shown to block neoplastic invasion and improve survival in animal models of malignancy. Concern about the effects of MMP inhibitors on wound and anastomotic healing may limit their potential use in the perioperative period to prevent local and systemic showering of cancer cells from surgical manipulation. We sought to assess the safety of perioperative administration of an MMP inhibitor (BB-94) with respect to skin and bowel healing in a rat model. Absorption of BB-94 was confirmed through high-pressure liquid chromatography and mass spectroscopy of sera from treated animals. Bowel bursting pressure in all animals increased almost 10-fold between 4 and 14 days. Two-way analysis of variance showed no significant difference in bowel bursting pressure between control and treatment animals over time. There was a significant increase in the collagen content of skin specimens of all animals combined between 4 and 28 days. Similarly, all animals showed an increase in bowel collagen between 4 and 28 days. There was no significant difference in skin or bowel collagen concentrations between control and treatment animals over time. Perioperative treatment with MMP inhibition does not impair wound or enteric healing in a rat model of laparotomy and small bowel resection. MMP inhibitors are safe for use as adjuvant therapy after resection for cancer.

Update on pancreatic cancer

Pancreatic cancer is one of the commonest causes of cancer death worldwide. Patients with pancreatic cancer benefit from resectional surgery (improved quality of life) and adjuvant treatment (enhanced survival). This review covers advances in the understanding of the development of pancreatic cancer, state-of-the-art clinical management and, finally, novel treatment and screening techniques.

Selective cleavage of human IgG by the matrix metalloproteinases, matrilysin and stromelysin

We have shown that two of the matrix metalloproteinases (MMPs), matrilysin and stromelysin-1, are capable of cleaving all of the human IgG subclasses. The cleavage occurs at a conserved site in the CH(2) domain of the heavy chain of IgG, releasing a single chain Fc-like fragment. We have not been able to demonstrate cleavage of IgA, IgD, IgM or IgE classes, which lack the cleavage site, nor could we show cleavage of IgG by collagenase, gelatinase, macrophage metalloelastase or membrane-type (MT)-MMP. This cleavage of IgG, by separating the antigen-binding (Fabprime prime or minute)(2) from the Fc portion, will remove much of the immunoglobulins' functionality, e.g. complement fixation, Fc receptor binding. In the context of a tumour producing matrilysin or stromelysin, this may represent a way in which the tumour protects itself from ADCC. In inflamed or damaged tissues where plasma protein leakage occurs, degradation by MMPs may be a mechanism for clearance of IgG.