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Several reports have attributed to green tea chemopreventive and therapeutic properties. Epidemiological studies have linked the regular use of green tea to a reduced incidence of breast and colon carcinomas. Tea contains several antioxidants, including polyphenols of the catechin (green tea) and theaflavin (black tea) groups. Green tea derivatives have been shown to act in vitro and in vivo as anti-inflammatory, anti-viral and anti-tumor drugs. Despite the extensive body of data only few studies have investigated the molecular mechanisms underlying these effects. In this brief review we focus on the inhibitory activity of catechins derived from green tea toward proteases involved in tumor invasion.

The HIV-1 Tat protein has been directly implicated in the pathogenesis of AIDS-related Kaposi's sarcoma (KS); however, its effects on KS spindle-shaped and endothelial cell apoptosis are largely unexplored. Since susceptibility to apoptosis is relevant for tumor development and response to therapy, we investigated the effects of Tat on KS and endothelial cell survival from apoptosis. The effect of Tat was evaluated in three KS cell lines (KS-imm, KS-C1, and KS-L3) exposed to the chemotherapy agent vincristine, currently used for the treatment of this tumor, and in human umbilical vein-derived endothelial cells (HUVECs) induced to undergo apoptosis by serum withdrawal. Apoptosis was assessed by enzymatic assays, microscopic examination of chromatin and cytoskeleton, evaluation of plasma membrane integrity and subdiploid DNA content, TUNEL assays, and measurement of caspase-3 activity. Tat, in a dose-dependent manner, protected the three KS cell lines and HUVECs from apoptosis induced by vincristine or serum starvation, respectively. This effect appeared to be independent of modulation of Fas, Bcl-2, or Bax expression. In contrast, Tat upregulated Bcl-X(L) expression and induced a relevant decrease in caspase-3 activity in vincristine-treated KS cells. Taken together, these results suggest that the HIV-1 Tat protein may factor KS development and progression by sustaining endothelial and transformed cell survival.

Following damage to skeletal muscle, satellite cells become activated, migrate towards the injured area, proliferate, and fuse with each other to form myotubes which finally mature into myofibers. We tested a new approach to muscle regeneration by incorporating myoblasts, with or without the exogenous growth factors bFGF or HGF, into three-dimensional gels of reconstituted basement membrane (matrigel). In vitro, bFGF and HGF induced C2C12 myoblast proliferation and migration and were synergistic when used together. In vivo, C2C12 or primary i28 myoblasts were injected subcutaneously together with matrigel and growth factors in the flanks of nude mice. The inclusion of either bFGF or HGF increased the vascularization of the gels. Gels supplemented with bFGF showed myogenesis accompanied by massive mesenchymal cell recruitment and poor organization of the fascicles. Samples containing HGF showed delayed differentiation with respect to controls or bFGF, with increased myoblast proliferation and a significantly higher numbers of cells in myotubes at later time points. HGF samples showed limited mesenchymal cell infiltration and relatively good organization of fascicles. The use of both bFGF and HGF together showed increased numbers of nuclei in myotubes, but with bFGF-mediated fibroblast recruitment dominating. These studies suggest that an appropriate combination of basement membrane components and growth factors could represent a possible approach to enhance survival dispersion, proliferation, and differentiation of myogenic cells during muscle regeneration and/or myoblast transplantation. This model will help develop cell therapy of muscle diseases and open the future to gene therapy approaches., (Copyright 2001 Wiley-Liss, Inc.)

In this study we analyse the frequency of testicular microlithiasis in a group of otherwise infertile healthy men, visited at the Andrology Service of Prato Hospital. Here the ultrasound machine is located in the ambulatory and it is possible to use it during the first visit of the patient, as we have done in 250 consecutive infertile men. This examination, easy and not invasive, has been performed to evaluate the pampiniform plexus to find possible varicocele, epydidimis for obstructive signs and testes for the presence or absence of parenchymal calcifications or masses. We found 106 positive sonographic records (42.4%) for scrotal diseases. Between them, two cases of testicular microlithiasis (0.8% of 250 consecutive ultrasound examinations and 1.7% in the last twelve months). Our data, although with a lower incidence than literature, show the importance of ultrasound examination in absence of specific diagnostic questions too, in the study of male infertility. Clinical management of testicular microlithiasis is difficult, due to loss of treatment and to cancer risk. A long term follow up is request, with periodical (6-12 months) sonographic controls. A classification (here we propose) can be useful for a more precise monitoring.

The extracellular activities of the human immunodeficiency virus (HIV) transactivator protein (Tat) include induction of angiogenesis and stimulation of monocyte migration. Here it is shown that polymorphonuclear leukocytes (PMNL), mostly neutrophils, rapidly invade in response to Tat in vivo and initiate the formation of new vessels. In vitro, Tat was chemotactic for PMNL and induced calcium (Ca(2+)) mobilization. Tat proteins with inactivating substitutions in the arginine-glycine-aspartic acid or basic domain were still active in inducing PMNL migration, whereas Tat peptides mapped the migration and Ca(2+) mobilization activity to a cysteine-rich core domain, previously described as a Tat "chemokine-like" region (peptide CysL(24-51)). Tat and the CysL(24-51) peptide also induced PMNL superoxide production and the release of the angiogenic factors interleukin-8 and vascular endothelial growth factor from PMNL. CysL(24-51) did not induce endothelial cell migration but was angiogenic in vivo. These data indicate that the Tat activity on PMNL is mediated by its chemokine-like region and that PMNL recruitment by Tat is linked to angiogenesis.

Kaposi's sarcoma (KS) is an hyperplastic lesion whose main histological features are typical spindle shaped cells with a mixed endothelial-mesenchymal-macrophage phenotype, an intense vascularization and an inflammatory infiltrate. The etiology of KS appears to be linked to activation of a latent HHV8 infection. Sporadic and iatrogenic KS are slow progressing lesions that can undergo spontaneous regression. In contrast, KS, which is frequently associated with HIV infection, is found in a highly aggressive form in AIDS patients. The HIV-1 Tat has been shown to activate the VEGF receptor KDR in endothelial and KS spindle cells, suggesting this HIV protein could contribute to KS pathogenesis. We used primary 'reactive' KS cell culture from sporadic and epidemic KS, and an immortal KS-line (KS-Imm) isolated in our laboratory from a iatrogenic KS lesion, to verify if Tat-induced cell signaling is able to mediate cellular responses. We demonstrate that KS cells migrated in response to Tat and that VEGF is able to compete with the Tat chemotactic activity towards these cells. A function-blocking anti-KDR antibody was able to abrogate both VEGF and Tat-induced KS chemotactic response, indicating a direct involvement of this receptor. Our data show that HIV-Tat can also activate KS cells derived from sporadic or iatrogenic lesions, suggesting that in AIDS patients Tat could cooperate with VEGF in activation of KDS on KS precursor spindle and endothelial cells, and contribute to the aggressiveness of AIDS-KS lesions., (Copyright 2000 Academic Press.)

Certain chemokines inhibit HIV replication through binding to cell surface receptors which also act as viral coreceptors. Based on our previous observations that HIV-1 Tat can interact with alpha- and beta-chemokine receptors, we investigated the potential effect of extracellular Tat (ecTat) on infection and replication of CCR5-dependent (R5) and CXCR4-using (X4) HIV-1 strains in primary activated peripheral blood mononuclear cells (PBMC) of uninfected donors. Receptor desensitization and binding competition studies were used to determine chemokine receptor binding by ecTat. Standard HIV replication assays based on reverse transcriptase (RT) activity determination in culture supernatants of PBMC and real time PCR for HIV-1 gag DNA were used to determine potential effects on early (entry or RT) steps of infection. ecTat bound to CXCR4 expressing monocytes and mitogen-activated PBMC, and competed with the natural ligand of CXCR4, SDF-1alpha (stromal cell-derived factor-1alpha) in calcium mobilization assays. EcTat inhibited replication of the X4 HIV-1 (LAI/IIIB strain) in activated PBMC at concentrations close to those of SDF-1alpha, whereas it only modestly interfered with R5 HIV-1 (BaL) replication in PBMC. Both SDF-1alpha and ecTat inhibited accumulation of X4 HIV-1 gag DNA, indicating interference with viral entry and/or RT. Our data show the surprising and counter-intuitive observation that ecTat selectively represses X4 HIV replication. This could favour spreading of R5 viruses, a condition observed in vivo immediately after transmission and in the early asymptomatic phase of infection., (Copyright 2000 Academic Press.)

We developed an in vivo gene therapy approach to characterize and optimize the anti-angiogenic activity of class I interferons (IFNs), using packaging cell lines producing an amphotropic LXSN-based retrovirus expressing either IFN-alpha1 (alpha1Am12), IFN-beta (betaAm12) murine cDNAs, or the vector alone (neoAm12). Pretreatment of endothelial-like Eahy926 cells in vitro with conditioned media (CM) from alpha1Am12 or betaAm12 cells for 48 hours significantly inhibited their migration and invasion as compared to neoAm12-CM-treated cells. betaAm12-CM also inhibited the formation of capillary-like structures on Matrigel by EAhy926 cells. In vivo, inclusion of the betaAm12 cells strongly inhibited, and alpha1Am12 partially inhibited, the angiogenic response in the Matrigel sponge model in both immune-competent and athymic nude mice. Electron microscopy showed a reduction of host cell infiltration in alpha1Am12- and betaAm12-containing sponges and reduction of invading tubular clefts of host cells as compared to controls. Finally, inoculation of either alpha1Am12 or betaAm12 cells (10%) along with a highly angiogenic Kaposi's sarcoma cell line (90%) resulted in a powerful reduction of tumor growth in nude mice in vivo, as did infection with the interferon-alpha-producing retroviruses. These data suggest that a gene therapy approach using class I interferons can effectively inhibit tumor angiogenesis and growth of vascular tumors.

A central role in tissue invasion is played by proteases that degrade extracellular matrices; in particular specific metalloproteases (MMPs) have been frequently correlated with the invasive potential of tumor cells and with the angiogenic process. MMPs are tightly regulated by molecules controlling their activation and by specific inhibitors of MMPs, known as the Tissue Inhibitors of MetalloProteases or TIMPs. Four TIMP family members are currently known. An imbalance between MMPs and TIMPs is linked to the degradation of the extracellular matrix associated with several physiologic and pathologic events including angiogenesis, invasion and metastasis. TIMPs are not only the 'guardians' of tissue degradation, they are able to control cell proliferation and cell survival as well. Given the critical role that TIMPs play, it is vital to know how the expression of TIMPs is controlled. Here we review the major biological properties and the molecular regulation of the TIMP expression.

Kaposi's sarcoma (KS), a neoplasm often associated with iatrogenic and acquired immunosuppression, is characterized by prominent angiogenesis. Angiogenic factors released by both KS and host cells, as well as HHV-8 and HIV viral products, have been implicated in the pathogenesis of this lesion. Angiogenesis is the result of imbalance among angiogenesis promoters and inhibitors, which disrupts homeostasis. The aim of this study was to investigate the expression and mechanism of KS control of thrombospondin-1 (TSP), a physiological inhibitor of angiogenesis. Immunohistochemical analysis of four KS lesions showed only spotty reactivity for TSP in the stroma and in less than 10 per cent of lesional blood vessels. In addition, the typical KS spindle cells were not stained. In agreement with these findings, decreased levels of TSP were measured with an ELISA assay in the supernatants of cultured KS cells, compared with endothelial cells. In vitro, TSP inhibited the endothelial cell proliferation and motility induced by KS cell supernatants. TSP also prevented endothelial cell motility induced by Tat, a product of HIV-1 endowed with angiogenic potential and implicated in the pathogenesis of AIDS-KS. In vivo, TSP inhibited the angiogenic activity exerted by Tat in the Matrigel sponge model. These results suggest that TSP down-regulation might be permissive for the development of KS-associated angiogenesis., (Copyright 1999 John Wiley & Sons, Ltd.)

The HIV-1 Tat protein is a potent chemoattractant for monocytes. We observed that Tat shows conserved amino acids corresponding to critical sequences of the chemokines, a family of molecules known for their potent ability to attract monocytes. Synthetic Tat and a peptide (CysL24-51) encompassing the "chemokine-like" region of Tat induced a rapid and transient Ca2+ influx in monocytes and macrophages, analogous to beta-chemokines. Both monocyte migration and Ca2+ mobilization were pertussis toxin sensitive and cholera toxin insensitive. Cross-desensitization studies indicated that Tat shares receptors with MCP-1, MCP-3, and eotaxin. Tat was able to displace binding of beta-chemokines from the beta-chemokine receptors CCR2 and CCR3, but not CCR1, CCR4, and CCR5. Direct receptor binding experiments with the CysL24-51 peptide confirmed binding to cells transfected with CCR2 and CCR3. HIV-1 Tat appears to mimic beta-chemokine features, which may serve to locally recruit chemokine receptor-expressing monocytes/macrophages toward HIV producing cells and facilitate activation and infection.

Objective and Design: Extracellular Tat released from HIV-1-infected cells is a mitogenic and motogenic factor for endothelial and Kaposi's sarcoma (KS)-derived cells and is angiogenic in vivo. Here we show for the first time that Tat induces migration of human dendritic cells in a concentration-dependent manner and that the Arg-Gly-Asp (RGD) and basic Tat peptides contribute to dendritic and monocyte cell migration. In vivo, Tat stimulates invasion of macrophages into a matrigel sponge., Methods: Monocyte and dendritic cell chemotaxis was assessed using the Boyden chamber assay., Results: Tat induced migration of monocyte-derived dendritic cells at the same levels as the N-formyl-Met-Leu-Phe peptide, and of monocytes at levels comparable to RANTES. Peptide mapping of the chemotactic activity of Tat showed that the RGD domain, which has been shown to support integrin-mediated cell migration, and the basic domain which binds and activates the tyrosine kinase receptor KDR on endothelial cells, both had activity. Antibody-blocking experiments indicate that responses to the RGD domain was inhibited by beta1 and alpha vbeta3 integrin blocking antibodies. Combination of the Tat RGD and basic peptides did not show additive effects; however, Tat co-operated with macrophage-chemotactic protein or RANTES in inducing monocyte migration., Conclusions: Our results show that Tat can act as a chemoattractant for dendritic cells, and that both the RGD and basic domains are involved in this response. These same domains attract monocytes. The alpha vbeta3 and beta1 integrins are equally involved in Tat-induced monocyte migration, while the alpha vbeta3 integrin largely mediates the dendritic cell response to Tat.

Objective: Kaposi's sarcoma (KS), a condition often associated with HIV infection, is more common in men than in women; pregnancy and sex hormones could be involved. Urinary human chorionic gonadotrophin (hCG) has been reported to inhibit the growth of KS cell lines, with great variability among preparations. Urinary hCG often contains free forms of the hCG subunits and a fragment of the free beta-subunit, the beta-core, which may have biological activity. We compared the effect of the beta-core fragment, the beta-subunit, recombinant and urinary hCG on KS immortal and spindle cells., Design and Methods: A new immortal KS cell line was phenotypically and karyotypically characterized. The effects on growth of this cell line and of primary KS spindle cells by hCG and its purified derivatives were tested. Induction of apoptosis was demonstrated using acridine orange/ethidium bromide staining., Results: The beta-core fragment harboured the most potent growth inhibitory activity on a molar basis. After 72 h of treatment with the beta-core, 60-70% of KS cells show apoptotic nuclei. No effects were observed on endothelial cells., Conclusions: The beta-core fragment of hCG proved to be the most effective part of the hCG molecule, inducing growth inhibition and apoptosis of KS cells. Thus, the beta-core could be the most appropriate hCG derivative for the therapy of KS.

During endochondral bone formation, avascular cartilage differentiates to hypertrophic cartilage that then undergoes erosion and vascularization leading to bone deposition. Resting cartilage produces inhibitors of angiogenesis, shifting to production of angiogenic stimulators in hypertrophic cartilage. A major protein synthesized by hypertrophic cartilage both in vivo and in vitro is transferrin. Here we show that transferrin is a major angiogenic molecule released by hypertrophic cartilage. Endothelial cell migration and invasion is stimulated by transferrins from a number of different sources, including hypertrophic cartilage. Checkerboard analysis demonstrates that transferrin is a chemotactic and chemokinetic molecule. Chondrocyte-conditioned media show similar properties. Polyclonal anti-transferrin antibodies completely block endothelial cell migration and invasion induced by purified transferrin and inhibit the activity produced by hypertrophic chondrocytes by 50-70% as compared with controls. Function-blocking mAbs directed against the transferrin receptor similarly reduce the endothelial migratory response. Chondrocytes differentiating in the presence of serum produce transferrin, whereas those that differentiate in the absence of serum do not. Conditioned media from differentiated chondrocytes not producing transferrin have only 30% of the endothelial cell migratory activity of parallel cultures that synthesize transferrin. The angiogenic activity of transferrins was confirmed by in vivo assays on chicken egg chorioallantoic membrane, showing promotion of neovascularization by transferrins purified from different sources including conditioned culture medium. Based on the above results, we suggest that transferrin is a major angiogenic molecule produced by hypertrophic chondrocytes during endochondral bone formation.

The HIV-1 Tat protein transactivates HIV, viral and some host cell genes. Tat can be released by infected cells and acts extracellularly in the microenvironment, regulating functions of immunocompetent and mesenchymal cells. One of the most striking effects of Tat is the induction of a functional program in vascular cells related to angiogenesis and inflammation (migration, proliferation and expression of plasminogen activator inhibitor-1 and E selectin). Tat induces growth of Kaposi's sarcoma (KS) spindle cells and is angiogenic in vivo and in transgenic mice10-12. We previously reported that Tat is a direct angiogenic factor and noted the Tat arginine- and lysine-rich sequence is similar to that of other potent angiogenic growth factors, such as vascular endothelial growth factor-A (VEGF-A). It is possible that Tat mimics one of these factors by interacting with its growth factor tyrosine kinase receptor. Here we demonstrate that Tat specifically binds and activates the Flk-1/kinase insert domain receptor (Flk-1/KDR), a VEGF-A tyrosine kinase receptor (for review see ref. 13), and that Tat-induced angiogenesis is blocked by agents blocking the Flk-1/KDR receptor. Endothelial cell stimulation by Tat occurs in the absence of activation of FLT-1, another VEGF-A tyrosine kinase receptor.

Abundant vasculature with increased permeability is a prominent histological feature of Kaposi's sarcoma (KS), a multifocal, cytokine-regulated tumor. Here we report on the role of vascular endothelial growth factor (VEGF) in AIDS-KS angiogenesis and vascular permeability. We demonstrate that different cytokines, which were previously shown to be active in KS development, modulate VEGF expression in KS spindle cells and cooperate with VEGF on the functional level. Northern blot analysis as well as studies on single cells using in situ hybridization revealed that VEGF expression in cultivated AIDS-KS spindle cells is up-regulated by platelet-derived growth factor-B and interleukin-1 beta. Western blot and enzyme-linked immunosorbent assay analysis of cell culture supernatants demonstrated that the VEGF protein is secreted by stimulated AIDS-KS spindle cells in sufficiently high amounts to activate proliferation of human dermal microvascular endothelial cells. Basic fibroblast growth factor did not increase VEGF expression but acted synergistically with VEGF in the induction of angiogenic KS-like lesions in a mouse model in vivo. Angiogenesis and cellularity of KS-like lesions were clearly increased when both factors were injected simultaneously into the flanks of mice, compared with separate injection of each factor. A comparable angiogenic reaction as obtained by simultaneous injection of basic fibroblast growth factor and VEGF was observed when cell culture supernatants of AIDS-KS spindle cells were used for these experiments. Finally, analysis of primary human AIDS-KS lesions revealed that high amounts of VEGF mRNA and protein were present in KS spindle cells in vivo. These data provide evidence that VEGF, in concert with platelet-derived growth factor-B, interleukin-1 beta, and basic fibroblast growth factor, is a key mediator of angiogenesis and vascular permeability in KS lesions in vivo.

We have analyzed by PCR skin lesions from classic, endemic and AIDS-related Kaposi's sarcoma (KS), as well as from KS-derived cell lines, the presence of ubiquitous transforming viruses. BK virus (BKV), a transforming human papovavirus which has been associated with human tumors, was detected in 100% of KS skin lesions and 75% of KS cell lines. KS specimens contained a full-length, intact BKV early region, but minor rearrangements were observed in some tumors. BKV was also detected with a high prevalence (57-67%) in genital tissues and sperm, thus fulfilling the role of a sexually transmitted agent in KS. The closely related JC virus (JCV), which has never been associated with human malignancies, was present in 11-20% of KS specimens and was detected with a low prevalence (0-21%) in genital tissues and sperm. Simian virus 40 (SV40) was not detected in any KS lesions. Herpes simplex virus (HSV) DNA sequences were detected in 20-25% of KS lesions. Malignant human papillomavirus (HPV) types 16 and 18 and benign HPV types 6 and 11 were detected in KS specimens with a similar prevalence of 11-83%, suggesting that the presence of HPV-transforming sequences is not a specific trait of HPV interaction with KS tissue. Furthermore, JCV, SV40, HSV and HPV DNA sequences were not detected in KS cell lines, suggesting that these viruses are not associated to KS neoplastic cells in KS tissue. KS cell lines were also negative for DNA sequences of KS-HV, the novel herpesvirus detected in primary KS lesions. The constant association of BKV DNA with KS lesions and KS cell lines suggests that BKV-transforming functions may participate in the development of KS.

Objective: To characterize the T53 cell line and its clones derived from an adenocarcinoma of BK virus (BKV)/tat transgenic mice and to establish the role of native Tat in tumorigenicity, induction of metastases and angiogenesis., Design and Methods: Tat was quantified by flow cytometry and chloramphenicol acetyltransferase (CAT) assays. Tumorigenicity and metastatic ability of cell lines were assayed in nude mice. Production of proteases was evaluated by a plasmin chromogenic assay and gelatinase zymography. The angiogenic effect was studied in vivo with conditioned medium from tumour cell lines., Results: Tat protein was detected in tumour cell lines in amounts from 600-7000 molecules/cell. Conditioned medium from tumour cell lines was able to transactivate an LTR-CAT in HL3T1 cells, indicating release of extracellular Tat. Tumour cell lines, inoculated into nude mice induced angiogenic tumours with remarkable recruitment of host endothelial cells. Metastases were detected in lymph nodes, lungs, kidneys, and heart. Cell lines produced relevant amounts of proteases. Conditioned medium implanted in mice with matrigel induced an angiogenic response, enhanced by addition of heparin. Preincubation with an anti-Tat antibody abolished the angiogenic effect., Conclusions: Tat from cells from BKV/tat transgenic mice promotes tumorigenesis and formation of metastases and induces angiogenic activity. Angiogenesis occurs at physiological concentrations of Tat lower than 20 ng/ml. The effects of Tat on induction of metastases and angiogenesis appear to be mediated by activation of proteases.

Transgenic animal studies have linked the expression of the HIV-1 tat gene to the appearance of Kaposi's sarcoma (KS)-like lesions. We have recently shown that recombinant tat is angiogenic in vivo, and that tat angiogenic response is enhanced by heparin. Also in the rabbit cornea model, recombinant HIV-1 tat alone is poorly angiogenic, but gives a good response when combined with heparin. Like many angiogenic growth factors, tat has a basic domain similar to that of several heparin binding angiogenic factors, including FGF, VEGF and HGF, suggesting that this region is important in endothelial cell activation. We show that tat binds heparin sepharose with a high affinity, similar to bFGF. Binding of tat to the cell surface is also modulated by heparin. Biological activities of tat, such as induction of endothelial cell growth, migration and invasion in vitro are all enhanced by low concentrations and inhibited by high concentrations of heparin, as has been shown for other heparin-binding angiogenic factors. Heparan sulfate is also effective, whereas the unsulfated polysaccharide K5 does not enhance tat activity. Furthermore, a peptide encompassing the tat basic domain is able to induce growth and migration of endothelial cells, while an adjacent peptide is not. Our data indicate that the tat basic domain plays a key role in its vascular cell activation properties, and strongly suggest that extracellular HIV-tat is essentially a 'new' heparin-binding angiogenic factor.

Secretion of angiogenesis inhibitors and stimulators is modulated during in vitro differentiation of embryonic chick growth plate chondrocytes. Supernatants from dedifferentiated cells undergoing maturation to hypertrophic chondrocytes in suspension progressively inhibited vascular cell random migration and invasion of basement membrane matrix by endothelial cells. Maximal inhibition was exhibited by conditioned medium from hypertrophic chondrocytes. The same medium also repressed vascular cell migration induced by highly angiogenic Kaposi's sarcoma cell supernatants and prevented formation of an anastomosed network of tube-like structures by endothelial cells plated on matrigel. On the contrary, when the suspension culture of hypertrophic chondrocytes was supplemented with ascorbic acid, a condition leading to the formation of a mineralized tissue similar to calcified cartilage, a dramatic switch to production of angiogenic activity was observed. Medium conditioned by osteoblast-like cells derived from hypertrophic chondrocytes also induced vascular cell migration and invasion of basement membrane matrix. The presence of angiogenic activity in the conditioned medium was assessed also by an in vivo assay in mice using reconstituted basement membrane associated with heparin. Therefore, interactions of chondrocytes with their extracellular matrix are an absolute requirement for the expression of angiogenic activities by hypertrophic chondrocytes at late developmental stages.

Oncostatin M (OM) is a polypeptide cytokine that induces autocrine and paracrine effects on AIDS-Kaposi's sarcoma (KS) cells (Nair et al., Science, 255, 1430-1432, 1992; Miles et al., Science, 255, 1432-1434, 1992). The signalling pathways underlying this activation are largely unknown. We have found that OM binding to KS cell lines in vitro identifies a higher affinity binding site (Kd 10-20 pM) with a lower affinity (Kd 1.5 nM), high capacity binding site. The binding of OM to its receptor at the KS cell surface stimulates a rapid tyrosine phosphorylation of multiple proteins, including the p85 regulatory subunit of phosphatidylinositol-3-kinase (PI3K). In addition OM can stimulate the in vivo activation of PI3K and increases the PI3K activity in anti-phosphotyrosine and anti-src kinase family antibody directed immunoprecipitates. Genistein, an inhibitor of tyrosine kinases, inhibits the synthesis of phosphatidylinositol 3,4-biphosphate and the growth of KS cells. Finally, OM enhances tyrosine kinase activity in immune complex kinase assay performed with antibody anti-src kinase family. These data suggest that in KS cells OM can stimulate formation of tyrosine kinase co-ordinate signalling complexes, containing at least src kinase family and PI3K, which can drive the accumulation of the putative second-messengers D3-phosphorylated phosphoinositides.

Adenomatoid tumor of the epididymis is an uncommon lesion accounting for approximately 30% of all the paratesticular neoplasms. One case observed in this Urological Department is reported and a review of our series of paratesticular neoplasms treated in the last 10 years has been considered.

Retinoic acid (RA) is a potent inhibitor of the malignant phenotype and of tumour cell growth. We observed that in vitro RA treatment of a highly metastatic lung carcinoma cell line (C87) induced a marked reduction in the amount of the beta 4 integrin subunit. The downregulation of this adhesion molecule was assessed by immunofluorescence, immunoprecipitation, and northern analysis. In order to investigate the effects of RA on the malignant phenotype in C87 cells we performed morphological and functional analysis after RA treatment. We found that RA was able to produce marked changes in C87 cell shape, increasing the number of flat cells (90% of the total cell population), and significantly inhibiting the malignant and invasive phenotype of C87 cells. RA treatment suppressed their clonogenic potential in soft agar (control, 20 +/- 5; RA, 0), and strongly reduced their chemotactic and chemoinvasive capacity (chemotaxis: control, 231 +/- 5; RA, 28 +/- 0; chemoinvasion: control, 132 +/- 11; RA = 2 +/- 1). FACS analysis and cell count, however, indicated that RA reduced the growth of C87 cells only partially. After 72 h of treatment we observed only a 10% reduction in the S phase fraction of the cell population. Finally, the reduced lung colony-forming ability, observed after i.v. injection of RA-treated cells (lung foci/animal: RA-treated cells, 1 +/- 0.1; untreated, 8.5 +/- 0.8), further supports the conclusion that in this murine lung carcinoma cell line a marked reduction in the expression of the beta 4 integrin subunit is associated with a marked inhibition of the malignant phenotype.

In the initial phases of angiogenesis, endothelial cells must degrade and cross the vessel basement membrane, as do tumor cells during invasion and metastasis formation. Various metalloproteinases have been implicated in tumor cell invasion, in particular MMP-2 (72 kDa collagenase IV, gelatinase A), which has been demonstrated to be associated with tumor metastasis formation. Supernatants from AIDS-Kaposi sarcoma (KS) cells induce normal endothelial cells to invade through a reconstituted basement membrane (Matrigel) in vitro, which correlates with the angiogenic potential of KS cells in vivo. Here we demonstrate that two specific inhibitors of MMP-2, TIMP-2 and a peptide from the MMP-2 propeptide region (peptide 74), inhibit endothelial cell invasion induced by AIDS-KS cell supernatants. Smooth muscle cells were much less sensitive to these inhibitors. These data suggest that MMP-2 activation is a key event in endothelial cell invasion, the initial phase of tumor-associated neoangiogenesis. Inhibition of this enzyme could be an effective treatment for KS and tumor-associated angiogenesis.

The Authors present the preliminary results of a feasibility study on the use of adjuvant radiotherapy (6 Gy single fraction, postoperatively, "flash") as a new treatment modality for superficial bladder cancer (Ta-T1, N0, M0, previously relapsed or not, G I-III). The rationale for this study derives mainly from the favourable results obtained with external beam radiotherapy, when applied before interstitial radiotherapy as a method to avoid scar relapses. Data regarding 55 cases treated with the "flash" are compared retrospectively with those regarding more than 100 cases treated with different types of "conventional" adjuvant therapy at the INRCA Center of Urology, during the last 3-4 years. The Authors stress the need for a prospective, randomized study of selected cases, to clarify if an adjuvant therapeutic modality is superior to the others. The radiotherapeutic option ("flash"), however, clearly produces less iatrogenic damage than the others, and is simpler and cheaper.

A hospital-based case-control study on bladder and lower urinary tract cancers was conducted in the Prato area, where the textile industry is the main manufacturing sector (about 50,000 employees). "Cases" were male subjects, aged over 15 years in whom urothelial cancer had been diagnosed in the period 1980-1985; controls (two for each case) were subjects of the same sex and age with other urological diseases or cancer of the prostate or testis. Cases and controls were interviewed via a questionnaire on occupational history and personal habits. A positive association was found for subjects who had worked in the textile industry (O.R. = 1.42; C.I. = 1.0-2.0). Analysis by job titles showed positive association for "rag selectors" (O.R. = 4.09; C.I. = 1.39-11.96), whereas no association was found for dyers (O.R. = 0.74; C.I. = 0.29-1.87).

The aetiopathogenesis and clinical picture of 3 cases of priapism are described, along with the treatment employed. The first patient suffered from thalassaemia minor, whereas in the second case priapism was a manifestation of aneurysm of the abdominal aorta perforated in the cava. In the last case, erection was a sequela of surgery for hydrocoele performed under peridural anaesthesia.

Acetate in predilution in bicarbonate dialysis with AN69 S. The purpose of this work was to assess whether bicarbonate dialysis, with infusion of acetate in predilution, using an AN69-S filter, offered some advantage over bicarbonate and acetate dialysis. In a period of 16 months we analysed 11 patients with this method, comparing them with one group of 7 patients in bicarbonate dialysis and another of 11 in acetate dialysis. The following parameters were investigated: acid-basic balance, HCT, weight and the intradialytic symptoms. There was some improvement in both objective and subjective parameters in patients treated by this method compared to patients in the control groups and the results were lasting.