New fluorescent 2-phenylindolglyoxylamide derivatives as probes targeting the peripheral-type benzodiazepine receptor: design, synthesis, and biological evaluation

Fluorescent ligands for the peripheral-type benzodiazepine receptor (PBR) featuring the 7-nitrobenz-2-oxa-1,3-diazol-4-yl moiety were synthesized, based on N,N-dialkyl-2-phenylindol-3-ylglyoxylamides, a potent, selective class of PBR ligands previously described by us. All the new ligands are moderately to highly potent at the PBR, with a complete selectivity over the central benzodiazepine receptor. Results from fluorescence microscopy showed that these probes specifically labeled the PBR at the mitochondrial level in C6 glioma cells.     

5-amino-2-phenyl[1,2,3]triazolo[1,2-a][1,2,4]benzotriazin-1-one: a versatile scaffold to obtain potent and selective A3 adenosine receptor antagonists

Binding assays on human A1, A2A, and A3 adenosine receptors (ARs) and functional studies on A2B ARs revealed that various 2-phenyl[1,2,3]triazolo[1,2-a][1,2,4]benzotriazin-1,5(6H)-diones VIII, previously reported as ligands at the central benzodiazepine receptor (BzR), possess nanomolar affinity at the A3 AR. Replacement of the amide of VIII with an amidine moiety gave the 5-amino-2-phenyl[1,2,3]triazolo[1,2-a][1,2,4]benzotriazin-1-ones IX, which maintain a nanomolar potency at the A3 AR with selectivity over the BzR. Insertion of a p-methoxybenzoyl at the 5-amino moiety enhanced A3 AR affinity and selectivity over the A1, A2A, and A2B ARs. The best result of our lead optimization efforts is 9-chloro-5-(4-methoxybenzoyl)amino-2-phenyl[1,2,3]triazolo[1,2-a][1,2,4]benzotriazin-1-one (23), which displayed a Ki of 1.6 nM at the A3 AR and no significant affinity at the other ARs or the BzR. Docking simulations on selected ligands into a model of the A3 AR allowed us to rationalize the structure-activity relationships of phenyltriazolobenzotriazindiones VIII and aminophenyltriazolobenzotriazinones IX at the molecular level.     

Simple enucleation for the treatment of renal angiomyolipoma

OBJECTIVES: To report on the role of simple enucleation for treating renal angiomyolipoma (AML) in a series of patients treated in our department. PATIENTS AND METHODS: We retrospectively reviewed the data of all 37 patients with a histopathological diagnosis of renal AML who had either radical nephrectomy (three) or nephron-sparing surgery by simple enucleation (34) between January 1986 and December 2005. Indications for intervention included either symptomatic AML or a tumour of >4 cm, regardless to the presence of symptoms or renal masses suspicious of malignancy. The patients' status was evaluated last in October 2006. RESULTS: The mean (sd, median, range) pathological tumour size was 5.2 (3.4, 4.8, 1.5-15) cm; five patients (15%) were affected by tuberous sclerosis. Simple enucleation was successful in all patients but in three (9%) a sharp dissection a few millimetres from the tumour was used during critical steps of the procedure where it seemed difficult to define the right plane of enucleation. Warm ischaemia was used in 79% of patients, with a mean ischaemic time of 11.2 min. Two patients (6%) required renal hypothermia. A simple parenchymal compression was used in five cases (15%). The mean (range) intraoperative blood loss was 170 (70-650) mL. None of the patients had postoperative bleeding requiring re-intervention but one (3%) required two units of blood after surgery. There were no major complications, e.g. prolonged acute tubular necrosis/chronic renal insufficiency and urinary leakage/urinoma, but two patients had urosepsis not associated with perirenal fluid collection and that required targeted antibiotic therapy. At a mean (median, range) follow-up of 56 (50.5, 10-120) months none of the patients had local tumour recurrence. Two patients had a small AML elsewhere in the operated kidney, detected 18 and 36 months after surgery, with a kidney recurrence rate of 6%. CONCLUSIONS: Our data confirm the optimum results of simple enucleation for renal AMLs; this technique provides excellent long-term local control and no patient had urinary leakage/fistula afterward.     

Reconstruction of the right atrium with pulmonary artery homograft after resection of right atrial lipomatosis

We present a case of large right atrial mass due to lipomatous hypertrophy of the interatrial septum and left lower lobe adenocarcinoma. Combined resections of the right atrial mass with reconstruction of the superior atriocaval junction and right atrial free wall defects with pulmonary artery homograft and wedge excision of the lung tumor were performed through median sternotomy.     

Thoracic endograft positioning and carotid-subclavian bypass grafting in a patient with a saccular aneurysm at the aortic arch

A 75-year-old man was referred to our hospital because of sudden thoracic pain. A saccular aneurysm of the aortic arch extending on the anterior surface of the aortic arch was found on computed tomographic arteriography. The patient was hemodynamically stable and he was programmed for a staged surgical and endovascular approach (hybrid approach). As a first stage and in order to prevent major cardiac complications due to the overstenting of the left subclavian artery (LSA) with the occlusion of the aortocoronary bypass, the patient underwent a polytetrafluoroethylene bypass graft (GORE-TEX, W.L. Gore & Associates, Flagstaff, AZ) between the LSA and the left carotid artery. Intraoperative arteriography revealed a good patency of the left carotid-subclavian bypass and of the left internal mammary bypass on the left anterior descending artery. As a second stage the endovascular procedure was accomplished 5 days later in the operating room. A Gore TAG stent graft (W.L. Gore & Associates) was deployed in the aortic arch 20 mm proximally to the aneurysmatic segment covering the ostium of the LSA. The postoperative course was uneventful and the patient was discharged on the fifth postoperative day in good general conditions. Hybrid procedures for treatment of aneurysms of the aortic arch or of the descending thoracic aorta are a promising alternative to open surgery especially in high-risk patients, with lower early morbidity and mortality rates. Long-term effectiveness remains to be fully elucidated.     

Induction of neural-like differentiation in human mesenchymal stem cells derived from bone marrow, fat, spleen and thymus

Mesenchymal stem cells (MSCs) from bone marrow (BM) and sub-cutaneous fat are known to differentiate into neural cells under appropriate stimuli. We describe here the neural-like differentiation of human MSCs obtained from spleen and thymus, induced either with chemical factors or with co-culture with human Schwann cells (Sc). Under the effect of neural differentiation medium, most MSCs from BM, fat, spleen and thymus acquired morphological changes suggestive of cells of astrocytic/neuronal and oligodendroglial lineages with general up-regulation of neural molecules not correlated with morphological changes. The process was transient and reversible, as MSCs recovered basal morphology and phenotype, as well as their multilineage differentiation potential. Thus, we hypothesized that chemical factors may prime MSCs for neural differentiation, by inducing initial and poorly specific changes. By contrast, co-cultures of MSCs of different origin with Sc induced long-lasting and Sc differentiation, i.e., the expression of Sc myelin proteins for up to 12 days. Our results show that a MSC reservoir is present in tissues other than BM and fat, and that MSCs of different origin have similar neural differentiation potential. This evidence provides new insights into BM-like tissue plasticity and may have important implications for future therapeutic interventions in chronic neuropathies.     

4E-binding protein 1: a key molecular "funnel factor" in human cancer with clinical implications

In an attempt to identify molecules that clearly reflect the oncogenic role of cell signaling pathways in human tumors, we propose a concept we term "funnel factor", a factor where several oncogenic signals converge and drive the proliferative signal downstream. In studies done in various tumor types, the expression of key cell signaling factors, including Her1 and Her2 growth factor receptors, as well as the RAS-RAF-mitogen-activated protein kinase and the phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin pathways was correlated with the associated clinicopathologic characteristics of these tumors. The downstream factors p70, S6, 4E-binding protein 1 (4E-BP1), and eukaryotic translation initiation factor 4E, which play a critical role in the control of protein synthesis, survival, and cell growth, were also analyzed. We found that phosphorylated 4E-BP1 (p-4E-BP1) expression in breast, ovary, and prostate tumors is associated with malignant progression and an adverse prognosis regardless of the upstream oncogenic alterations. Thus, p-4E-BP1 seems to act as a funnel factor for an essential oncogenic capability of tumor cells, self-sufficiency in growth signals, and could be a highly relevant molecular marker of malignant potential. Further investigation into this concept may identify additional funnel factors in the oncogenic pathways and provide potential therapeutic targets.     

Altered methionine metabolism and global DNA methylation in liver cancer: relationship with genomic instability and prognosis

Mounting evidence underlines the role of genomic hypomethylation in the generation of genomic instability (GI) and tumorigenesis, but whether DNA hypomethylation is required for hepatocellular carcinoma (HCC) development and progression remains unclear. We investigated the correlation between GI and DNA methylation, and influence of methionine metabolism deregulation on these parameters and hepatocarcinogenesis in c-Myc and c-Myc/Tgf-alpha transgenic mice and human HCCs. S-adenosyl-L-methionine/S-adenosylhomocysteine ratio and liver-specific methionine adenosyltransferase (MatI/III) progressively decreased in dysplastic and neoplastic liver lesions developed in c-Myc transgenic mice and in human HCC with better (HCCB) and poorer (HCCP) prognosis (based on patient's survival length). Deregulation of these parameters resulted in a rise of global DNA hypomethylation both in c-Myc and human liver lesions, positively correlated with GI levels in mice and humans, and inversely correlated with the length of survival of HCC patients. No changes in MATI/III and DNA methylation occurred in c-Myc/Tgf-alpha lesions and in a small human HCC subgroup with intermediate prognosis, where a proliferative activity similar to that of c-Myc HCC and HCCB was associated with low apoptosis. Upregulation of genes involved in polyamine synthesis, methionine salvage and downregulation of polyamine negative regulator OAZ1, was highest in c-Myc/Tgf-alpha HCCs and HCCP. Our results indicate that alterations in the activity of MAT/I/III, and extent of DNA hypomethylation and GI are prognostic markers for human HCC. However, a small human HCC subgroup, as c-Myc/Tgf-alpha tumors, may develop in the absence of alterations in DNA methylation.     

Identification and chromosome mapping of loci predisposing to colorectal cancer that control Wnt/beta-catenin pathway and progression of early lesions in the rat

Sporadic colorectal cancer (CRC) is a major health concern worldwide. Epidemiologic evidence suggests a polygenic predisposition to CRC, but the genes responsible remain unknown. Here, we performed genome-wide scanning of male (ACI/SegHsd x Wistar-Furth)F2 (AWF2) rats to map susceptibility genes influencing the evolution of early colorectal lesions to adenocarcinoma following 1,2-dimethylhydrazine administration. Phenotypic analysis revealed higher incidence/multiplicity and lower size of adenomas in ACI/SegHsd (ACI) and (ACI/SegHsd x Wistar-Furth)F1 (AWF1) than Wistar-Furth (WF) rats and higher incidence/multiplicity of poorly differentiated adenocarcinomas in WF than ACI rats, with intermediate values in AWF1 rats. Linkage analysis of 138 AWF2 rats identified three loci on chromosomes 4, 15 and 18 in significant linkage with lesion multiplicity that were identified as rat Colon cancer resistance (rCcr) 1, rCcr2 and rCcr3, respectively. Seven other loci on chromosomes 5, 6, 15, 17, 18 and 20 were in suggestive linkage with adenoma/adenocarcinoma multiplicity/surface area. Six of them were identified as rCcr4-9 and a locus on chromosome 5 was identified as a susceptibility locus, rCcs1. Significant interactions between rCcr3 and rCcr6, rCcr6 and rCcr8 and rCcr5 and rCcr9, and four novel epistatic loci controlling multiplicity/size of colorectal lesions were discovered. Apc, located at rCcr3, did not show functional promoter polymorphisms. However, influence of susceptibility/resistance genes on Wnt/beta-catenin pathway was shown by defective beta-catenin inactivation in WF but not in ACI and AWF1 rat adenocarcinomas. These data indicate that inheritance of predisposition to CRC depends on interplays of several genetic factors, and suggest a possible mechanism of polygenic control of CRC progression.