Clinical and pharmacological phase I evaluation of Exherin (ADH-1), a selective anti-N-cadherin peptide in patients with N-cadherin-expressing solid tumours.

BACKGROUND: Upregulation of N-cadherin promotes dysregulated cell growth, motility, invasiveness, plus maintenance of vascular stability and is associated with cancer progression in several human tumour types. N-cadherin is expressed also on tumour cells and the anti-N-cadherin cyclic pentapeptide ADH-1, tested in the present study, can exert a direct antitumour effect. PATIENTS AND METHODS: Adult patients with advanced solid malignancies expressing N-cadherin on tumour biopsies carried out in the previous 12 months received escalating i.v. doses of ADH-1 given weekly (initially for 3 of 4 weeks, then every week). Plasma pharmacokinetics (PK) was studied at cycle 1. Blood flow changes were assessed after first dosing in all patients treated in the initial regimen. RESULTS: In all, 129 patients were screened, 65 (50%) were N-cadherin positive, and 30 were enrolled. The doses ranged from 150 to 2400 mg/m(2); no maximum tolerated dose was reached. Treatment was well tolerated with asthenia as the most frequent adverse event. Two patients with ovarian cancer showed prolonged disease stabilisation while one patient with fallopian tube carcinoma achieved a mixed response. PK was linear in the range of doses tested. CONCLUSION: ADH-1 is the first anti-N-cadherin compound tested in humans. In N-cadherin-positive patients, ADH-1 showed an acceptable toxicity profile, linear PK and hints of antitumour activity in gynaecological cancers.

Middle mesenteric artery: contraindication to endovascular repair of an abdominal aortic aneurysm?

Middle mesenteric artery has been described in 1923. We report the observation of a patient with an abdominal aortic aneurysm who had this rare artery arising from the anterior wall of the aneurysmal sac. His inferior mesenteric artery was occluded at its origin from the aorta and the middle and the distal colon was vascularized only by the middle mesenteric artery. Occlusion of this artery would have been necessary before endovascular repair of the aneurysm. We were concerned about the risk of colic ischemia after the occlusion of the middle mesenteric artery, so we abandoned this approach and operated on the patient via a laparotomy. Based on a case report, we here report a literature overview on the repair of abdominal aortic aneurysm in the presence of a middle mesenteric artery.

Extrahepatic arterioportal fistula: three-dimensional reconstruction of computerized tomodensitometric scan for diagnosis and morphologic assessment.

Arterioportal fistulae (APFs) are rare. An asymptomatic APF was suspected by computed tomography. Multiplanar, maximum intensity projection, and surface shaded display reconstructions showed its anatomy. To our knowledge, this is the first report using such reconstructions to analyze the architecture of an extrahepatic APF. Complete assessment of APF can be achieved noninvasively, and initial endovascular treatment can be planned.

Pelvimetry by magnetic resonance imaging as a diagnostic tool to evaluate dystocia.

OBJECTIVE: To test the clinical value of magnetic resonance imaging (MRI) pelvimetry for the diagnosis of cephalopelvic disproportion. METHODS: All deliveries from January 1993 through December 1994 were reviewed to identify 42 nulliparas at term with vertex presentation and cesarean delivery due to dystocia. Complete data were available for 41 women, and subjects were divided into the following two subgroups, according to clinical data: "cephalopelvic disproportion" (n = 28) and "failure to progress" (n = 13). Ten nulliparous women with uncomplicated vaginal delivery served as controls. Pelvimetry data from postpartum MRI were correlated with fetal and neonatal dimensions to evaluate various criteria for the diagnosis of cephalopelvic disproportion. RESULTS: Comparing both the fetal head volume derived from antepartum ultrasound assessment and the neonatal head volume (postpartum measurement) with maternal pelvic capacity determined by MRI, cephalopelvic disproportion (head volume exceeding pelvic capacity) indicated that 25 and 27, respectively, of the 28 women had been clinically diagnosed correctly with cephalopelvic disproportion, corresponding to sensitivities of 89% and 96%, respectively. Fetal head volume was not larger than pelvic capacity in any of the women in the control group. In seven of the 13 women diagnosed as "failure to progress," the fetal head volume exceeded the pelvic capacity. CONCLUSION: A fetal head volume estimate exceeding MRI-measured pelvic capacity is a frequent finding in nulliparas with cesarean birth due to cephalopelvic disproportion. An appropriate prospective study to determine the benefits of an antepartum diagnosis of cephalopelvic disproportion in high-risk nulliparas is warranted.

The effect of the chemotherapeutic drug VP-16 on poly(ADP-ribosylation) in apoptotic HeLa cells.

We have studied the effect of the chemotherapeutic drug VP-16 (etoposide) on the metabolism of HeLa cells by analysing different cellular parameters; in particular we have focused on changes in cellular morphology that are considered as markers of apoptosis. By immunofluorescence experiments we have shown that VP-16 causes the complete disruption of nucleoli and induces chromatin margination and fragmentation. Agarose gel electrophoresis of DNA from cells treated with 10-100 microM VP-16 showed the appearance of a characteristic ladder due to the internucleosomal DNA cleavage. The effect of etoposide on DNA integrity was not prevented by preincubation of cells with the protein synthesis inhibitor cycloheximide. These results provide experimental evidence indicating that the typical features of apoptosis are visible in HeLa cells exposed to VP-16. In this experimental system we have investigated whether the ADP-ribosylation process could be regulated by the presence of DNA fragments. By means of the activity gel technique, which allows the direct evaluation of automodified poly(ADP-ribose)polymerase, we have observed that in extracts from cells where etoposide-induced DNA fragmentation occurred, the autoribosylated form of the enzyme is greatly increased. Ribosylated poly(ADP-ribose)polymerase has been isolated by affinity chromatography on boronate column from cells permeabilized and labelled with [32P]NAD. Drug exposure caused a strong augmentation of modified enzyme. These observations suggest that activation of ADP-ribosylation process occurs in cells that show the typical features of apoptosis.

DNA topoisomerase II beta: stability and distribution in different animal cells in comparison to DNA topoisomerase I and II alpha.

DNA topoisomerase I and the isoforms alpha and beta of DNA topoisomerase II were analyzed in different animal cells using a panel of monoclonal antibodies (MoAbs). The beta isoform is a most unstable enzyme. We investigated conditions to stabilize beta isoform because its variability changes according to the derivation of cells. We describe two MoAbs specific to DNA topoisomerase I: the first one recognizes the enzyme in all the species tested including fish; the second one, in contrast, recognizes an epitope present only in mammalian cells. We also found that eight of eight MoAbs against DNA topoisomerase II alpha and five of six against the beta isoform recognize the respective enzymes in all the species tested excluding fish. In addition, MoAbs to the alpha isoform are specific to epitopes not present in the carboxyl third of the enzyme.

Multiple DNA-protein interactions at the CpG island of the human pseudoautosomal gene MIC2.

The human MIC2 gene is pseudoautosomal and in females it escapes X inactivation. At the 5' end of the gene a 1.2-kb-long CpG island has been identified that is unmethylated on the active X, the inactive X, and on the Y chromosome. We have demonstrated by 5' RACE experiments that this region contains the transcription start site of the gene. To better characterize this CpG island, we have investigated the interaction between this region and nuclear proteins in vitro by using DNA gel mobility shift and DNase I footprinting techniques. Band shift experiments with HeLa cell nuclear extract have indicated that all the island is involved in multiple interactions with nuclear proteins. Experiments with a eukaryotic purified Sp1 protein have shown that this factor specifically binds to several sites of the island. Three DNase I protected footprints have been identified in the region between nucleotides -122 and +34 with respect to the transcription initiation site. By using a recombinant Sp1 protein, we have shown that all the footprints are due to the binding of Sp1. The sequences of two footprints correspond to the decanucleotide binding site for Sp1, the sequence of the third one does not contain any published Sp1 recognition site.

DNA binding properties of FCE24517, an electrophilic distamycin analogue.

The distamycin derivative FCE24517 binds both reversibly and irreversibly to DNA. At 37 degrees C, the drug originates reversible complexes that are strong enough to survive to the electrophoretic separation of the substrate. These complexes slowly evolve to covalent adducts (10(-4) adducts/bp/h) that eventually degenerate to single-strand breaks (1.5 x 10(-5) nicks/bp/h). The site of attack by the drug can be any base in the vicinity of AT-rich regions of the double helix. Rapidly reassociating duplex DNA molecules, indicative of the presence of cross-links, are observed only upon boiling of DNA with FCE24517. While the low rates of formation of covalent adducts and DNA breaks could be relevant for the long-term biological effects of FCE24517, the specific formation of strong but still reversible complexes with DNA could be matched to the drastic and sudden reduction of thymidine incorporation induced by this electrophilic distamycin.