A microRNA code for prostate cancer metastasis.

Although the development of bone metastasis is a major detrimental event in prostate cancer, the molecular mechanisms responsible for bone homing and destruction remain largely unknown. Here we show that loss of miR-15 and miR-16 in cooperation with increased miR-21 expression promote prostate cancer spreading and bone lesions. This combination of microRNA endows bone-metastatic potential to prostate cancer cells. Concomitant loss of miR-15/miR-16 and gain of miR-21 aberrantly activate TGF-ß and Hedgehog signaling, that mediate local invasion, distant bone marrow colonization and osteolysis by prostate cancer cells. These findings establish a new molecular circuitry for prostate cancer metastasis that was validated in patients' cohorts. Our data indicate a network of biomarkers and druggable pathways to improve patient treatment.

Lulwoana sp., a dark septate endophyte in roots of Posidonia oceanica (L.) Delile seagrass.

Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anchored on rock than on matte and sand. In root sections, an inter- and intracellular septate mycelium, producing intracellular microsclerotia, was detected from the rhizodermis to the vascular cylinder. Using isolation techniques, we obtained, from both sampling sites, sterile, slow-growing fungal colonies, dark in colour, with septate mycelium, belonging to the dark septate endophytes (DSEs). DNA sequencing of the internal transcribed spacer (ITS) region identified these colonies as Lulwoana sp. To our knowledge, this is the first report of Lulwoana sp. as DSE in roots of P. oceanica. Moreover, the highest fungal colonisation, detected in P. oceanica roots growing on rock, suggests that the presence of the DSE may help the host in several ways, particularly in capturing mineral nutrients through lytic activity.

TAZ is required for metastatic activity and chemoresistance of breast cancer stem cells.

Metastatic growth in breast cancer (BC) has been proposed as an exclusive property of cancer stem cells (CSCs). However, formal proof of their identity as cells of origin of recurrences at distant sites and the molecular events that may contribute to tumor cell dissemination and metastasis development are yet to be elucidated. In this study, we analyzed a set of patient-derived breast cancer stem cell (BCSC) lines. We found that in vitro BCSCs exhibit a higher chemoresistance and migratory potential when compared with differentiated, nontumorigenic, breast cancer cells (dBCCs). By developing an in vivo metastatic model simulating the disease of patients with early BC, we observed that BCSCs is the only cell population endowed with metastatic potential. Gene-expression profile studies comparing metastagenic and non-metastagenic cells identified TAZ, a transducer of the Hippo pathway and biomechanical cues, as a central mediator of BCSCs metastatic ability involved in their chemoresistance and tumorigenic potential. Overexpression of TAZ in low-expressing dBCCs induced cell transformation and conferred tumorigenicity and migratory activity. Conversely, loss of TAZ in BCSCs severely impaired metastatic colonization and chemoresistance. In clinical data from 99 BC patients, high expression levels of TAZ were associated with shorter disease-free survival in multivariate analysis, thus indicating that TAZ may represent a novel independent negative prognostic factor. Overall, this study designates TAZ as a novel biomarker and a possible therapeutic target for BC.

BTG2 loss and miR-21 upregulation contribute to prostate cell transformation by inducing luminal markers expression and epithelial-mesenchymal transition.

Prostate cancer is one of the leading causes of cancer-related death in men. Despite significant advances in prostate cancer diagnosis and management, the molecular events involved in the transformation of normal prostate cells into cancer cells have not been fully understood. It is generally accepted that prostate cancer derives from the basal compartment while expressing luminal markers. We investigated whether downregulation of the basal protein B-cell translocation gene 2 (BTG2) is implicated in prostate cancer transformation and progression. Here we show that BTG2 loss can shift normal prostate basal cells towards luminal markers expression, a phenotype also accompanied by the appearance of epithelial-mesenchymal transition (EMT) traits. We also show that the overexpression of microRNA (miR)-21 suppresses BTG2 levels and promotes the acquisition of luminal markers and EMT in prostate cells. Furthermore, by using an innovative lentiviral vector able to compete with endogenous mRNA through the overexpression of the 3'-untranslated region of BTG2, we demonstrate that in prostate tumor cells, the levels of luminal and EMT markers can be reduced by derepression of BTG2 from microRNA-mediated control. Finally, we show that the loss of BTG2 expression confers to non-tumorigenic prostate cells ability to grow in an orthotopic murine model, thus demonstrating the central role of BTG2 downregulaton in prostate cancer biology.

Signaling crosstalk between TGFß and Dishevelled/Par1b.

Crosstalk of signaling pathways is critical during metazoan development and adult tissue homeostasis. Even though the transforming growth factor-beta (TGFß) transduction cascade is rather simple, in vivo responsiveness to TGFß ligands is tightly regulated at several steps. As such, TGFß represents a paradigm for how the activity of one signaling system is modulated by others. Here, we report an unsuspected regulatory step involving Dishevelled (Dvl) and Par1b (also known as MARK2). Dvl and Par1b cooperate to enable TGFß/bone morphogenetic protein (BMP) signaling in Xenopus mesoderm development and TGFß responsiveness in mammalian cells. Mechanistically, the assembly of the Par1b/Dvl3/Smad4 complex is fostered by Wnt5a. The association of Smad4 to Dvl/Par1 prevents its inhibitory ubiquitination by ectodermin (also known as transcriptional intermediary factor 1 gamma or tripartite motif protein 33). We propose that this crosstalk is relevant to coordinate TGFß responses with Wnt-noncanonical and polarity pathways.

beta-Catenin initiates tooth neogenesis in adult rodent incisors.

beta-Catenin signaling is required for embryonic tooth morphogenesis and promotes continuous tooth development when activated in embryos. To determine whether activation of this pathway in the adult oral cavity could promote tooth development, we induced mutation of epithelial beta-catenin to a stabilized form in adult mice. This caused increased proliferation of the incisor tooth cervical loop, outpouching of incisor epithelium, abnormal morphology of the epithelial-mesenchymal junction, and enhanced expression of genes associated with embryonic tooth development. Ectopic dental-like structures were formed from the incisor region following implantation into immunodeficient mice. Thus, forced activation of beta-catenin signaling can initiate an embryonic-like program of tooth development in adult rodent incisor teeth.

Is quantitative histologic examination useful to predict nonorgan-confined prostate cancer when saturation biopsy is performed?

OBJECTIVES: To evaluate the role of quantitative histologic findings in predicting nonorgan-confined (non-OC) prostate cancer (PCa) in patients undergoing saturation prostate biopsy (SPBx). METHODS: A total of 69 patients who had undergone SPBx underwent radical retropubic prostatectomy. Their prostate-specific antigen level was <10 ng/mL, and 49 and 20 patients had T1c and T2 PCa, respectively. The following biopsy variables from the quantitative histologic examination were evaluated as predictive of OC vs non-OC PCa: Gleason score (6), total percentage of PCa (20%), greatest percentage of PCa (50%), number of PCa-positive cores (2), presence of PCa-positive cores in both lateral margins (yes vs no), and PCa localization (unilateral vs bilateral). The results obtained from patients who had undergone SPBx were compared with those of 183 patients who had undergone 12-core prostate biopsy before radical retropubic prostatectomy. RESULTS: Overall, 32 patients had non-OC PCa. Among the men with Stage T1c PCa, the quantitative histologic findings were predictive of non-OC PCa in 12 of 17 cases. The area under the receiver operating characteristic curve was 0.935 +/- 0.29, supporting the high accuracy of quantitative histologic examination in predicting for non-OC PCa. The sensitivity in patients who underwent SPBx vs the 12-core biopsy was 78.1% and 89.4%, respectively. Also, although the specificity of each histologic parameter was significantly lower in the SPBx group, it was equivalent using quantitative histologic examination (85.6% vs 86.5%). CONCLUSIONS: In the preoperative staging of patients with clinical Stage T1c-T2 PCa and a prostate-specific antigen level <10 ng/mL who had undergone SPBx, quantitative histologic examination demonstrated good accuracy in predicting for non-OC PCa only when all pathological variables were considered.

Report of a case of discoid lupus erythematosus localised to the oral cavity: immunofluorescence findings.

Discoid Lupus Erythematosus (DLE) is a chronic disease with a typical cutaneous involvement. This pathology rarely involves mucosa: oral cavity is interested in 20 percent of DLE patients. We describe a case of oral DLE in a 50-year-old woman with an anamnesis for autoimmune disorders. This study shows the helpful role of immunofluorescence in the diagnosis of autoimmune diseases. The first diagnostic step was the clinical observation of the oral mucosa: the lesion area was erythematous, atrophic and hyperkeratotic. The patient then underwent laboratory examination. We utilized human epithelial cells (Hep-2010) for Indirect Immuno-Fluorescence (IIF). Moreover, the biopsy site for Direct Immuno-Fluorescence (DIF) and histopathological analysis was the untreated oral lesion. IIF detected an increase of Anti-Nuclear Antibody (ANA) and positivity for SSA-RO. By DIF, we observed IgG/IgA/fibrinogen along basal layer. Multiple biopsies reported signs of chronic basal damage. Steroid systemic therapy induced a considerable lesion regression. We suggest the use of immunofluorescence with the integration of further data to improve diagnosis of rare diseases and to establish a suitable therapy.

A mutually stimulating loop involving emx2 and canonical wnt signalling specifically promotes expansion of occipital cortex and hippocampus.

The correct size of the different areas composing the mature cerebral cortex depends on the proper early allocation of cortical progenitors to their distinctive areal fates, as well as on appropriate subsequent tuning of their area-specific proliferation-differentiation profiles. Whereas much is known about the genetics of the former process, the molecular mechanisms regulating proliferation and differentiation rates within distinctive cortical proto-areas are still largely obscure. Here we show that a mutual stimulating loop, involving Emx2 and canonical Wnt signalling, specifically promotes expansion of the occipito-hippocampal anlage. Collapse of this loop occurring in Emx2-/- mutants leads progenitors within this region to slow down DNA synthesis and exit prematurely from the cell cycle, due to misregulation of cell cycle-, proneural- and lateral inhibition-molecular machineries, and eventually results in dramatic and selective size-reduction of occipital cortex and hippocampus. Reactivation of canonical Wnt signalling in the same mutants rescues a subset of molecular abnormalities and corrects differentiation rates of occipito-hippocampal progenitors.

Cerberus-like is a secreted BMP and nodal antagonist not essential for mouse development.

Mouse cerberus-like (cer-l) is a member of the Cerberus/Dan family of secreted factors. As other members of this family of proteins, Cer-l functions in the extracellular space, inhibiting signaling molecules. Here we show that the neural-inducing and mesoderm-inhibiting activities of Cer-l result from specific binding to BMP and Nodal molecules, respectively. These properties resemble the ones from the related factor Xenopus Cerberus. However, Xenopus Cerberus in addition to BMP4 and Nodal also binds to and inhibits Wnt proteins. We show that Cer-l does not directly inhibit Wnt signals. A null allele of the mouse Cer-l gene was generated by targeted inactivation in ES cells. Homozygous embryos show no anterior patterning defects, are born alive, and are fertile. Since mouse Cer-l and Xenopus Cerberus differ in biochemical activities, we propose the existence of additional members of this family of inhibitors, which may compensate for the loss of cer-l.

BMP-binding modules in chordin: a model for signalling regulation in the extracellular space.

A number of genetic and molecular studies have implicated Chordin in the regulation of dorsoventral patterning during gastrulation. Chordin, a BMP antagonist of 120 kDa, contains four small (about 70 amino acids each) cysteine-rich domains (CRs) of unknown function. In this study, we show that the Chordin CRs define a novel protein module for the binding and regulation of BMPs. The biological activity of Chordin resides in the CRs, especially in CR1 and CR3, which have dorsalizing activity in Xenopus embryo assays and bind BMP4 with dissociation constants in the nanomolar range. The activity of individual CRs, however, is 5- to 10-fold lower than that of full-length Chordin. These results shed light on the molecular mechanism by which Chordin/BMP complexes are regulated by the metalloprotease Xolloid, which cleaves in the vicinity of CR1 and CR3 and would release CR/BMP complexes with lower anti-BMP activity than intact Chordin. CR domains are found in other extracellular proteins such as procollagens. Full-length Xenopus procollagen IIA mRNA has dorsalizing activity in embryo microinjection assays and the CR domain is required for this activity. Similarly, a C. elegans cDNA containing five CR domains induces secondary axes in injected Xenopus embryos. These results suggest that CR modules may function in a number of extracellular proteins to regulate growth factor signalling.

Cisplatin-epirubicin-paclitaxel weekly administration in advanced breast cancer: a phase I study of the Southern Italy Cooperative Oncology Group.

PURPOSE: Both cisplatin and epirubicin have been shown to enhance the antitumor activity of paclitaxel in vitro. Weekly administration could result in a substantial improvement in the therapeutic index of cisplatin and paclitaxel. This study was aimed at determining the MTDs of epirubicin and paclitaxel given weekly with a fixed dose of cisplatin. PATIENTS AND METHODS: Sixty-three breast cancer patients with advanced disease (24 locally advanced and 39 metastatic), who had not received prior chemotherapy (except adjuvant), received weekly cisplatin (CDDP) doses of 30 mg/m2 together with escalating doses of paclitaxel (PTX) and epirubicin (EPI) for a minimum of six cycles. The dose escalation was stopped if DLT occurred during the first six treatment cycles in > 33% of patients of a given cohort. RESULTS: Nine different dose levels were tested, for a total of 506 weekly cycles delivered. G-CSF support on days 3-5 of each week was also given in the last four cohorts (24 patients). An overall 11 patients showed DLT in the first six cycles. EPI and PTX doses up to 40 and 85 mg/m2/week, respectively, were safely delivered without G-CSF support. However, the actually delivered mean dose intensity was only 64% in this cohort. Therefore, the dose escalation continued with the addition of filgrastim from day 3 to day 5 each week. Doses of EPI and PTX up to 50 and 120 mg/m2/week were administered without observing DLT in the first six cycles in more than one third of the patients enrolled. No toxic deaths were observed. Only two patients had to be hospitalized because of sepsis. Grade 3-4 neutropenia, thrombocytopenia, and anemia occurred in 25, 9, and 16 patients, respectively. Alopecia was almost universal. Other nonhematologic toxicities were generally mild, being of grade 3-4 in only eight patients (fatigue and loss of appetite in two cases, diarrhoea in four cases, peripheral neuropathy and mucositis in one case). Fifteen complete and 37 partial responses have been registered for an 82% (95% CI = 71-91) overall clinical response rate (ORR). Eight complete and 14 partial responses occurred in the 24 patients with locally advanced disease, for a 92% (95% CI = 73-99) ORR, as compared to seven complete and 23 partial responses in the 39 women with metastatic disease, 77% (95% CI = 61-89). A clear dose-response relationship was not observed, since an overall response rate of at least 70% was achieved at all dose levels. However, the ORR increased to 92% in the last four cohorts which included patients who received higher doses of EPI and PTX with G-CSF support. All of the 24 patients with locally advanced disease underwent modified radical mastectomy with axillary dissection. Three of them showed no invasive cancer on pathologic examination, and in another five patients a tumor smaller than 1 cm was found in the surgical specimen of the breast. At a nine-month median follow-up (range 2-14), 11 patients have progressed and three have died. Twenty-three out of 24 patients who underwent surgery are still free from progression. The one-year projected progression-free survival is 77% for the whole population. CONCLUSIONS: The CDDP/EPI/PTX weekly administration is a well tolerated and very effective approach in advanced breast cancer patients. Full doses of all the three drugs can be delivered even in absence of G-CSF support. A very impressive increment of the dose-intensity can be obtained, however, by adding filgrastim. A phase II study is under way to better define the therapeutic efficacy of this regimen in patients with advanced breast cancer.

The head inducer Cerberus is a multifunctional antagonist of Nodal, BMP and Wnt signals.

Embryological and genetic evidence indicates that the vertebrate head is induced by a different set of signals from those that organize trunk-tail development. The gene cerberus encodes a secreted protein that is expressed in anterior endoderm and has the unique property of inducing ectopic heads in the absence of trunk structures. Here we show that the cerberus protein functions as a multivalent growth-factor antagonist in the extracellular space: it binds to Nodal, BMP and Wnt proteins via independent sites. The expression of cerberus during gastrulation is activated by earlier nodal-related signals in endoderm and by Spemann-organizer factors that repress signalling by BMP and Wnt. In order for the head territory to form, we propose that signals involved in trunk development, such as those involving BMP, Wnt and Nodal proteins, must be inhibited in rostral regions.

Cell type-specific transcription of the alpha1(VI) collagen gene. Role of the AP1 binding site and of the core promoter.

Analysis of the chromatin of different cell types has identified four DNase I-hypersensitive sites in the 5'-flanking region of the alpha1(VI) collagen gene, mapping at -4.6, -4.4, -2.5, and -0.1 kilobase (kb) from the RNA start site. The site at -2.5 kb was independent from, whereas the other three sites could be related to, alpha1(VI) mRNA expression. The site at -0.1 kb was present in cells expressing (NIH3T3 and C2C12) but absent in cells not expressing (EL4) the mRNA; the remaining two sites were apparently related with high levels of mRNA. DNase I footprinting and gel-shift assays with NIH3T3 and C2C12 nuclear extracts have located a binding site for transcription factor AP1 (activator protein 1) between nucleotides -104 and -73. When nuclear extracts from EL4 lymphocytes were used, the AP1 site-containing sequence was bound by proteins not related to AP1. The existence of the hypersensitive site at -0.1 kb may be related to the binding of AP1 and of additional factors to the core promoter (Piccolo, S., Bonaldo, P., Vitale, P., Volpin, D., and Bressan, G. M. (1995) J. Biol. Chem. 270, 19583-19590). The function of the AP1 binding site and of the core promoter in the transcriptional regulation of the Col6a1 gene was investigated by expressing several promoter-reporter gene constructs in transgenic mice and in cell cultures. The results indicate that regulation of transcription of the Col6a1 gene by different cis-acting elements (core promoter, AP1 binding site and enhancers) is not completely modular, but the final output depends on the specific interactions among the three elements in a defined cell type.

[The head inducer Cerberus in a multivalent extracellular inhibitor]. / L'inducteur céphalique Cerberus est un inhibiteur multivalent extracellulaire.

Cerberus encodes for a secreted protein which when overexpressed ventrally in a Xenopus embryo induces head differentiation without trunk (Bouwmeester et al., 1996). We have recently shown that Cerberus can bind BMP-4 (Bone Morphogenetic Protein-4), Xnr-1 (Xenopus Nodal-related 1) and Xwnt-8 in the extracellular space (Piccolo et al., 1999). We present here studies showing that Cerberus does not have a receptor nor a dedicated transduction pathway but rather acts as an extracellular inhibitor. Our results suggest that the action of Cerberus in head induction can be explained by an inhibitory activity upstream of the Nodal-related and BMP-4 receptors. In addition, using dominant negative receptor mutants which block both the Xnr-1 and BMP-4 transduction pathways, we show that this double inhibition is sufficient for head induction in ventral mesoderm explants.

Collagen VI deficiency induces early onset myopathy in the mouse: an animal model for Bethlem myopathy.

To gain insight into the function of type VI collagen, the col6a1 gene was inactivated by targeted gene disruption in the mouse. The homozygous mutants lacked collagen VI in the tissues and showed histological features of myopathy such as fiber necrosis and phagocytosis and a pronounced variation in the fiber diameter. Muscles also showed signs of stimulated regeneration of fibers. Necrotic fibers were particularly frequent in the diaphragm at all ages examined. Similar, although milder, alterations were detected in heterozygous mutant mice, indicating haploinsufficiency of the col6a1 gene function. The data led us to conclude that collagen VI is necessary for maintenance of the integrity of muscle fibers and that the col6a1 -deficient mouse can be considered an animal model of Bethlem myopathy.

Scintimammography with 99mTc-MDP: experience of the National Cancer Institute of Naples.

The role of scintimammography with 99mTc-MDP was investigated in patients with mammographic or clinical evidence of breast lesions, suspicious for malignancy, in our Department at the National Cancer Institute of Naples. The end-point of the study was to assess the uselfulness of this test in diagnosing or ruling out breast cancer in more than 2000 women. Scintimammography results were compared with those of mammography and ultrasound and categorized according to histological findings. Overall sensitivity was 92%, specificity was 90%, and accuracy 91%. Sensitivity was affected by the lesions exceeding 12 mm and specificity by sclerotic and/or hyaline or myxoid fibroadenomas, which may be positive. The major advantages of scintimammography appeared in the study of calcifications without a mass and of the indirect mammographic signs of breast cancer, such as distortion and asymmetry. Scintimammography with 99mTc-MDP is a reliable, safe and highly cost-effective procedure to diagnose or to rule out breast cancer, after mammography and ultrasound have yielded questionable results.

Cleavage of Chordin by Xolloid metalloprotease suggests a role for proteolytic processing in the regulation of Spemann organizer activity.

The Xolloid secreted metalloprotease, a tolloid-related protein, was found to cleave Chordin and Chordin/BMP-4 complexes at two specific sites in biochemical experiments Xolloid mRNA blocks secondary axes caused by chordin, but not by noggin, follistatin, or dominant-negative BMP receptor, mRNA injection. Xolloid-treated Chordin protein was unable to antagonize BMP activity. Furthermore, Xolloid digestion released biologically active BMPs from Chordin/BMP inactive complexes. Injection of dominant-negative Xolloid mRNA indicated that the in vivo function of Xolloid is to limit the extent of Spemann's organizer field. We propose that Xolloid regulates organizer function by a novel proteolytic mechanism involving a double inhibition pathway required to pattern the dorsoventral axis: [formula in text].

Scintimammography with 99mTc-MDP in the detection of primary breast cancer.

MATERIALS AND METHODS: The diagnostic accuracy of scintimammography with 99mTc-MDP was evaluated in 400 consecutive women with clinical or mammographic suspicion of breast cancer, candidate to surgery and/or excisional biopsy. Lateral views of both glands were acquired, in prone position, 5-10 min after the injection of 550-740 MBq of 99mTc-MDP. The scintigraphic results were compared to mammograms and classified using the histological findings as gold standard. RESULTS: Mammography was suggestive for cancer in 231 (57%), suspicious in 49 (12%) and indeterminate in 120 (31%) patients. Breast carcinoma was histologically proven in 330 women, benign breast diseases in 70. The tumor size ranged from 4 x 5 to 50 x 60 mm. 99mTc-MDP visualized as foci of increased uptake 305/330 cancers (92%). In particular, in women with indeterminate mammograms the SMM had a diagnostic accuracy of 84%, correctly characterizing 101/120 lesions. Twenty missed cancers had largest diameter < or = 10 mm, 5 < or = 15 mm. Lack of 99mTc-MDP uptake occurred in 64 out of 70 benign lesions. These lesions were classified as truly negative. Conversely, 3 fibroadenoma and 3 epithelial hyperplasia with moderate or severe atypia were falsely positive. The overall specificity was 91.5%; the accuracy was 92%, the positive and negative predictive values were respectively 98% and 72%. CONCLUSIONS: The results obtained in this study suggest that 99mTc-MDP scintimammography accurately detects breast carcinomas with largest diameter > 10 mm; it differentiates malignant from benign lesions, and it shows promising insights in characterizing breast abnormalities mammographically indeterminate.