Membrane type 1 matrix metalloproteinase induces epithelial-to-mesenchymal transition in prostate cancer

By mining DNA microarray data bases at GenBank, we identified up-regulation of membrane type 1 matrix metalloproteinase (MT1-MMP) in human primary and metastatic prostate cancer specimens as compared with nonmalignant prostate tissues. To explore the role of up-regulated MT1-MMP in early stage cancer progression, we have employed a three-dimensional cell culture model. Minimally invasive human prostate cancer cells (LNCaP) were transfected with MT1-green fluorescent protein (GFP) chimeric cDNA as compared with GFP cDNA, and morphologic and phenotypic changes were characterized. GFP-expressing LNCaP cells formed multicellular spheroids with cuboidal-like epithelial morphology, whereas MT1-GFP-expressing cells displayed a fibroblast-like morphology and a scattered growth pattern in type I collagen gels. Cell morphologic changes were accompanied by decreased epithelial markers and enhanced mesenchymal markers, consistent with epithelial-to-mesenchymal transition. MT1-MMP-induced morphologic change and cell scattering were abrogated by target inhibition of either the catalytic domain or the hemopexin domain. We further demonstrated that MT1-MMP-induced phenotypic changes were dependent upon up-regulation of Wnt5a, which has been implicated in epithelial-to-mesenchymal transition. We conclude that MT1-MMP plays an important role in early cancer dissemination by converting epithelial cells to migratory mesenchymal-like cells.

[Prevention of nosocomial infections: surveillance based on microbiological data]

BACKGROUND

In the C. Poma Hospital of Mantua we have been using a system of continuous surveillance of nosocomial infections based on microbiological data for the past 4 years. This monitoring estimates the incidence of the microorganisms found in cultures, especially those at risk of causing nosocomial infections.

MATERIALS AND METHODS

Since June 2001 microbiological data have been registered using the Mercurio-Dianoema software and elaborated by means of Microsoft Excel in order to obtain information about isolated bacteria, especially those resistant to antibiotics.

RESULTS

Surveillance in "critical" wards revealed the presence of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans in the intensive care unit in the period 2003-2005. The most frequent bacteria in hemodialysis have been coagulase-negative Staphylococci and Staphylococcus aureus, with variable methicillin resistance.

CONCLUSION

The analysis of microbiological data has promoted effective measures to reduce the incidence of these bacteria (increased rules of good practice, hand washing, etc.). If nosocomial infections or high-risk microorganisms occur, assessments are carried out; monitoring of the antibiotic resistance of the bacteria is very important.

[Epidemiologic surveillance of multi-drug resistant Pseudomonas aeruginosa in Mantova Hospital (Italy)]

For the period 2002-2005 we verified and compared the data of the prevalence and resistance of Pseudomonas aeruginosa (PA) isolated in Mantova Hospital (Italy) with the data from the international database. From the first six-month period of 2004 a significant increase was found (9% vs 28.8%) in the prevalence of multi-drug resistant PA (MDR-PA). The principal wards involved were the Intensive Care Unit and the Department of Respiratory Diseases. A significant increase in resistance rates was observed for all antimicrobials tested, in particular for aztreonam, ceftazidime, ciprofloxacin, gentamycin and imipenem. The lowest dual resistance rates were observed between amikacina with piperacillin/tazobactam, while the highest were for those that included ciprofloxacin and beta-lactams (aztreonam, cefepime). In this study we confirm the importance of continuous surveillance of laboratory data and tightening local control measures for nosocomial infections in order to prevent the spread and selection of MDR-PA.

Membrane type 1-matrix metalloproteinase promotes human prostate cancer invasion and metastasis

Development of metastases requires cancer cells to breach underlying basement membrane, migrate through interstitial stroma and gain access to blood or lymphatic vessels. Membrane type 1-matrix metalloproteinase (MT1-MMP) has been linked with these processes. Expression of MT1-MMP in human prostate cancer correlates with the stage of this disseminated disease. The mechanism underlying this observation, however, still remains to be understood. To study the role of MT1-MMP in prostate cancer dissemination, endogenous and recombinant MT1-MMP expressed in human prostate cancer cell lines (DU-145 and LNCaP) were examined. Using FITC-labeled Matrigel, a soluble basement membrane extract coated coverslips, LNCaP cells stably expressing a chimera of MT1-MMP and Green Fluorescent Protein (MT1-GFP) degraded Matrigel and readily migrated over degraded substrates. The degradation of Matrigel by LNCaP cells expressing MT1-GFP was sensitive to MMP inhibitors, CT-1746 and TIMP-2, but not TIMP-1. Cell migration was dramatically enhanced by expression of MT1-MMP. By employing surgical orthotopic implantation of LNCaP cells stably expressing MT1-GFP into the prostate gland of immunodeficient mice, we demonstrated that MT1-MMP promotes lymph node and lung metastasis of prostate cancer cells. Together, these results emphasize the pivotal role of MT1-MMP in prostate cancer dissemination and confirm that MT1-MMP is a suitable target to prevent cancer metastasis.

Cyclic mechanical strain-induced proliferation and migration of human airway smooth muscle cells: role of EMMPRIN and MMPs

Airway smooth muscle (ASM) proliferation and migration are major components of airway remodeling in asthma. Asthmatic airways are exposed to mechanical strain, which contributes to their remodeling. Matrix metalloproteinase (MMP) plays an important role in remodeling. In the present study, we examined if the mechanical strain of human ASM (HASM) cells contributes to their proliferation and migration and the role of MMPs in this process. HASM were exposed to mechanical strain using the FlexCell system. HASM cell proliferation, migration and MMP release, activation, and expression were assessed. Our results show that cyclic strain increased the proliferation and migration of HASM; cyclic strain increased release and activation of MMP-1, -2, and -3 and membrane type 1-MMP; MMP release was preceded by an increase in extracellular MMP inducer; Prinomastat [a MMP inhibitor (MMPI)] significantly decreased cyclic strain-induced proliferation and migration of HASM; and the strain-induced increase in the release of MMPs was accompanied by an increase in tenascin-C release. In conclusion, cyclic mechanical strain plays an important role in HASM cell proliferation and migration. This increase in proliferation and migration is through an increase in MMP release and activation. Pharmacological MMPIs should be considered in the pursuit of therapeutic options for airway remodeling in asthma.

Furin Directly Cleaves proMMP-2 in the trans-Golgi Network Resulting in a Nonfunctioning Proteinase

Proprotein convertases play an important role in tumorigenesis and invasiveness. Here, we report that a dibasic amino acid convertase, furin, directly cleaves proMMP-2 within the trans-Golgi network leading to an inactive form of matrix metalloproteinase-2 (MMP-2). Co-transfection of COS-1 cells with both proMMP-2 and furin cDNAs resulted in the cleavage of the N-terminal propeptide of proMMP-2. The molecular mass of cleaved MMP-2 (63 kDa), detected in both cell lysates and conditioned medium, is between the intermediate and fully activated forms of MMP-2 induced by membrane type 1-MMP. Furin-cleaved MMP-2 does not possess proteolytic activity as examined in a cell-free assay. Treatment of transfected cells with a furin inhibitor resulted in a dose-dependent inhibition of proMMP-2 cleavage; recombinant tissue inhibitor of metalloproteinase-2, which binds to the active site of membrane type 1-MMP, had no inhibitory effect. Site-directed mutagenesis of amino acids in the furin consensus recognition motif of proMMP-2(R69KPR72) prevented propeptide cleavage, thereby identifying the scissile bond and characterizing the basic amino acids required for cleavage. Other experimental observations were consistent with intracellular furin cleavage of proMMP-2 in the trans-Golgi network. The furin cleavage site in other proMMPs was examined. MMP-3, which contains the RXXR furin consensus sequence, was cleaved in furin co-transfected cells, whereas MMP-1, which lacks an RXXR consensus sequence, was not cleaved. In conclusion, we report the novel observation that furin can directly cleave the RXXR amino acid sequence in the propeptide domain of proMMP-2 leading to inactivation of the enzyme.

Distinct Roles for the Catalytic and Hemopexin Domains of Membrane Type 1-Matrix Metalloproteinase in Substrate Degradation and Cell Migration

Substrate degradation and cell migration are key steps in cancer metastasis. Membrane-type 1-matrix metalloproteinase (MT1-MMP) has been linked with these processes. Using the fluorescein isothiocyanate (FITC)-labeled fibronectin degradation assay combined with the phagokinetic cell migration assay, structure-function relationships of MT1-MMP were studied. Our data indicate that MT1-MMP initiates substrate degradation and enhances cell migration; cell migration occurs as a concurrent but independent event. Using recombinant DNA approaches, we demonstrated that the hemopexin-like domain and a nonenzymatic component of the catalytic domain of MT1-MMP are essential for MT1-MMP-mediated cell migration. Because the cytoplasmic domain of MT1-MMP was not required for MT1-MMP-mediated fibronectin degradation and cell migration, it is proposed that cross-talk between the hemopexin domain of MT1-MMP and adjacent cell surface molecules is responsible for outside-in signaling. Employing cDNAs encoding dominant negative mutations, we demonstrated that Rac1 participates in the MT1-MMP signal transduction pathway. These data demonstrated that each domain of MT1-MMP plays a distinct role in substrate degradation and cell migration.

Morphological analysis of nevoid melanoma: a study of 20 cases with a review of the literature

Nevoid melanoma is a rare variant of melanoma characterized by deceptive morphologic features reminiscent of a benign melanocytic nevus. Twenty (13 nodular, 7 verrucous) nevoid melanomas were reviewed with the goal of identifying the predominant architectural patterns, cytologic features, and prognostic indicators. Although at scanning magnification, many lesions showed a strong resemblance to banal compound or dermal nevi, careful inspection in all cases demonstrated subtle pleomorphism and impaired maturation with depth, invariably accompanied by multiple dermal mitoses. Four tumors recurred and three metastasized, with subsequent death of the patients. Follow-up information for a period of at least 3 years was available in eight cases. In this group, mortality was 37.5%, the metastasis rate was 37.5%, and the local recurrence rate was 75%, with an average tumor thickness of 2.5 mm. We conclude that nevoid melanoma may be distinguished from a benign melanocytic nevus by a high index of suspicion, a careful analysis of architecture, and attention to cytologic features. Our data and a review of the literature do not support the notion that nevoid melanoma has a better prognosis than ordinary melanoma.

Cyclin D3 expression in normal, reactive and neoplastic tissues

Cyclin D3 immunohistochemical expression was investigated in normal, reactive, and neoplastic human embryonal and adult tissues. In the fetus, cyclin D3 was expressed in selected developmental phases of a limited number of cell systems. In normal adult tissues, cyclin D3 showed two patterns of distribution: in lymphoid tissues it was expressed in proliferative compartments, while in most other tissues it was expressed by terminally differentiated/quiescent cells. This dual role in proliferation and differentiation was partially conserved in neoplasms. In non-Hodgkin lymphomas, cyclin D3 immunolabelling was correlated with proliferative activity and progression; a significant exception was seen in cyclin D1-positive mantle cell lymphomas, which were cyclin D-negative. Benign endocrine tumours were frequently strongly cyclin D3-positive, while high-grade (small cell) neuroendocrine carcinomas were always negative. In most other epithelial neoplasms, cyclin D3 immunostaining was heterogeneous. In breast carcinomas, no relationship was seen between ER status and MIB1 labelling; cyclins D3 and D1 were frequently expressed in the same tumour, while occasional tumours showed an inverse quantitative relationship between cyclins D1 and D3, and rare tumours were negative for both. In soft tissue neoplasms, cyclin D3 was consistently expressed in some tumours, such as stromal tumours of the gastrointestinal tract and embryonal rhabdomyosarcomas. Our data suggest that cyclin D3 has a dual role in proliferation and differentiation in normal tissues and in some neoplastic conditions; that the cyclin D3 expression pattern is different from cyclin D1, suggesting non-redundant functions; that cyclin D3 expression is strong in endocrine cells secreting steroid hormones, and in their neoplastic counterparts; and that cyclin D3 deregulation may be of pathogenetic relevance in lymphomagenesis and could be diagnostically useful.

HpSS: a new silver staining method for Helicobacter pylori

AIMS

To verify whether the proposed new silver staining method compares favourably with other well established methods in the detection of Helicobacter pylori in gastric biopsies.

METHODS

One hundred and forty pairs of antral and fundic biopsies, routinely formalin fixed and paraffin wax embedded, from 70 consecutive unselected patients were stained with haematoxylin and eosin, modified Giemsa, and the proposed H pylori silver stain (HpSS). H pylori immunodetection was performed in the same material with a polyclonal antiserum against H pylori.

RESULTS

H pylori was detected in 89 biopsies from 48 patients with haematoxylin and eosin; in a further five biopsies (one antral and four fundic) with Giemsa stain, thereby identifying one more H pylori infected patient. The new silver staining method was positive in all the cases detected by these two methods and detected three extra infected patients (five more positive biopsies). Immunohistochemistry detected one more positive case (two positive biopsies) not identified by any of the other methods.

CONCLUSIONS

The HpSS method proposed is highly sensitive in detecting H pylori; it is simple and it compares well with other methods used routinely for evaluating gastric biopsies for H pylori.

Calretinin: a novel immunocytochemical marker for mesothelioma

Immunohistochemistry is a powerful diagnostic adjunct in the differential diagnosis between malignant mesothelioma (especially of the epithelial type) and adenocarcinoma metastatic to the serous membranes. Most of the immunological probes commonly used, however, recognize antigens expressed by the epithelial malignancies and absent from mesothelial cells and mesotheliomas. Probes suitable for the positive identification of mesotheliomas are comparatively scarce and much less commonly used because of their reduced sensitivity and specificity, their unsuitability for staining routinely fixed and embedded tissues, or their lack of commercial availability. We now document that two different polyclonal antisera to calretinin consistently immunostain mesothelial cells and malignant mesotheliomas both in routinely fixed and embedded tissue sections and in cytological preparations of serous effusions. The diagnostic sensitivity of this novel immunocytochemical approach reached 100%, allowing immunostaining of all 44 mesotheliomas investigated, which included five biphasic and three sarcomatoid types. The specificity of calretinin immunoreactivity was checked against 294 adenocarcinomas of different origin (19 serosal metastases and 275 primary tumors potentially able to metastatize to serosal membranes) relevant for the discussion of the differential diagnosis with malignant mesothelioma: only 28 cases showed focal immunoreactivity for calretinin. We conclude that calretinin is a most useful marker for the positive identification of malignant mesotheliomas.

Clinically silent inflammatory gut lesions in undifferentiated spondyloarthropathies

Gastrointestinal inflammation or infection can be associated with various forms of arthritis, such as, acute reactive arthritis triggered by enteritis due to gram-negative bacteria or ankylosing spondylitis and peripheral arthritis in relation to Crohn's disease and ulcerative colitis. Using colonoscopy, we have found a high prevalence of clinically silent inflammatory lesions in 38 patients (24 males and 14 females) affected by undifferentiated spondyloarthropathies (SpA). Microscopic inflammatory lesions were present in all the patients. Three patterns of nonspecific chronic inflammatory alterations were observed. No difference was noted between patients taking or not taking nonsteroidal anti-inflammatory drugs. Direct immunofluorescence demonstrated the presence of IgG, IgA, IgM, C3, C4 and fibrinogen in 75% of the specimens examined. The finding of chronic inflammatory gut lesions hypothesizes that a local activation of the immune system depending on the persistence of intestinal microbial antigens or toxins, due to impaired elimination or increased exposition, may have a part in the pathogenesis of SpA.

Improving pictures in dermatopathology

We have found that a remarkable improvement in the resolution of the details and in the richness of halftones can be obtained using 4" x 5" black-and-white professional films specifically prepared for scientific and documentary photography. Through modification of the developing time and developer dilution, a close control of the contrast and gray tones is also possible. Using this large-format film, a contact print can be made and top-quality pictures obtained even for a subject as difficult as skin pathology.

Positivity of patch tests in cutaneous reaction to diclofenac. Two case reports

Immune-mediated reactions to NSAIDs are unusual. We have observed two cases of maculopapular eruptions occurring 48-72 h after administration of diclofenac sodium. Patch tests performed with diclofenac were positive. The histopathologic findings resembled those of contact dermatitis with different degrees of dermal involvement. Clinical, allergologic, and histopathologic patterns strongly suggest a type IV mechanism of hypersensitivity. Patch tests play an important role in the assessment of possible immunologic mechanisms underlying cutaneous reactions to drugs.

The prevalence of BCL-2 immunoreactivity in breast carcinomas and its clinicopathological correlates, with particular reference to oestrogen receptor status

BCL-2 protein plays a pivotal role in overriding programmed cell death (apoptosis), thus favouring a prolonged survival of normal and neoplastic cells. Expression of the bcl-2 gene has been documented in some human tumours (non-Hodgkin's lymphomas and prostatic adenocarcinomas), but findings in breast carcinomas have not been reported. We have used the monoclonal antibody 124 to investigate BCL-2 expression in 212 breast carcinomas, and to correlate it with the oestrogen (ER), progesterone (PR) and epidermal growth factor receptor (EGFR) status, and with other clinicopathological variables including tumour type, grade, stage, growth fraction (as evaluated by Ki-67 immunostaining), and p53 accumulation. Of the 212 carcinomas, 173 (81.6%) exhibited BCL-2 immunoreactivity in more than 25% of the neoplastic cells. BCL-2 immunoreactivity was strongly correlated with ER and PR expression (P < 0.00001), with the lobular type (P = 0.012) and with better differentiated neoplasms (P = 0.00003), whereas it was inversely correlated with EGFR (P < 0.00001), p53 (P = 0.0004) and Ki-67 (P = 0.0002) immunoreactivities. No association was found with tumour stage (T and N categories). We conclude that bcl-2 expression in breast cancers is related to the oestrogen-dependent transcription pathway.

[Mucocutaneous lichen planus with esophageal involvement. A clinical case]

The paper reports the case of a 58-year-old woman suffering from mucosal and cutaneous lichen planus (LP) with esophageal and oral involvement, who had complained of dysphagia for approximately the past two years. The diagnosis of esophageal LP was made using esophagoscopy with mucosal biopsy. The differential diagnosis between LP and progressive systemic sclerosis is discussed; a cold-test, plethysmography of the limbs, an anti-ENA Sci-70 antibody assay, X-rays of soft tissues and esophagomanometry were performed for this purpose, and all proved normal. The presence of conditions implicated in the etiopathogenesis of LP (psychic disorders and the administration of psychoactive drugs, anti-hypertensives and FANS) were observed, together with an already known association with arterial hypertension. Altered hepatic function (with an increase in cholestasis enzymes) was also noted which is probably attributable to the prolonged use of psychoactive drugs (hepatic biopsy showed severe steatosis).

[Histological simulators of Kaposi's sarcoma in the initial phase]

Early Kaposi's sarcoma might be simulated by many different conditions, especially when the vascular component is prominent. the criteria suggested to differentiate early Kaposi's simulators are discussed. We found that these criteria are high in sensibility but low in specificity, therefore, we suggest using these criteria only when they are found in clusters.

The examination of illicit cocaine

A laboratory system of examination of illicit cocaine exhibits is described. Separation and identification of many of the components in exhibits are achieved by the use of capillary column gas chromatography and a Finnigan ion trap detector. Further examination and quantitation of the components of exhibits is achieved using two high performance liquid chromatographic (HPLC) systems. Both of these systems use identical reverse phase C8 columns. System 1 employs a solvent composed of 40% acetonitrile, 10% tetrahydrofuran and 50% 0.1% v/v aqueous triethylamine. The eluant is monitored at 280 nm. This system is preferred for routine quantitative analysis of cocaine and related alkaloids in exhibits. System 2 employs a solvent composed of 30% acetonitrile and 70% 0.05M phosphate buffer (pH = 5.0). The eluant from this system is monitored at both 220 and 280 nm. This system offers advantages in sensitivity. The relative retention times of a number of relevant substances as determined with gas chromatography and the two HPLC systems are given. The utility of the methodology for the identification and comparison of exhibits is demonstrated.