Bruna Scaggiante

Successful Therapy Of Niemann-pick Disease By Implantation Of Human Amniotic Membrane

In a patient with a lysosomal storage disorder, not involving the CNS, repeated implantations of human amniotic sheets have proved to provide a successful approach to enzyme replacement therapy. Implantation of pure epithelial cells, separated from the other cell types of the amnion, might markedly improve the procedure, avoiding some risks of host-versus-graft rejection.

Bortezomib arrests the proliferation of hepatocellular carcinoma cells HepG2 and JHH6 by differentially affecting E2F1, p21 and p27 levels.

Despite the broad anti-tumour potential of the proteasome inhibitor bortezomib, partial information is available with regard to its effects on hepatocellular carcinoma (HCC) cells. Here we studied the effects of bortezomib on two human HCC cell lines displaying a different phenotype, hepatocyte-like for HepG2 and undifferentiated for JHH6. Bortezomib induced a dose- and time-dependent increase in cell toxicity and decrease of cell viability, with JHH6 being less sensitive than HepG2. Moreover, a differential influence on major cell cycle regulatory genes was responsible for the observed decrease of S and increase of G(2)-M phase cells. In HepG2, bortezomib induced a post-transcriptional increase of cyclin E1 together with a transcriptional-mediated decrease of the transcription factor E2F1. This in turn resulted in the reduction of the hyper-phosphorylated form of pRB and in the transcriptional down-regulation of the E2F1 targets cyclin D1, cyclin A2 and CdK2 but not cyclin E1. Up-regulation of LRH1, a liver specific cyclin E1 transcription factor, accounted for the unvaried cyclin E1 mRNA levels. Additionally, bortezomib induced both transcriptional and post-translational increase of p21(waf1/cip1) and p27(kip1). In JHH6, an overall more contained variation in cell cycle mediators was observed with the reduction of E2F1, cyclin A2, LRH1 and the increase of p21(waf1/cip1) being the most evident. In conclusion, the presented data show the mechanisms regulating cell proliferation inhibition by bortezomib in two different HCC cell lines. Despite a certain phenotype-dependent effect, the potent action exerted by bortezomib makes this drug attractive for future experimentation in animal models, possibly leading to novel treatments for HCC.

Novel hepatocellular carcinoma molecules with prognostic and therapeutic potentials.

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is the sixth most common cancer worldwide and the third leading cause of cancer-related death. The difficulty to diagnose early cancer stages, the aggressive behaviors of HCC, and the poor effectiveness of therapeutic treatments, represent the reasons for the quite similar deaths per year and incidence number. Considering the fact that the diagnosis of HCC typically occurs in the advanced stages of the disease when the therapeutic options have only modest efficacy, the possibility to identify early diagnostic markers could be of significant benefit. So far, a large number of biomarkers have been associated to HCC progression and aggressiveness, but many of them turned out not to be of practical utility. This is the reason why active investigations are ongoing in this field. Given the huge amount of published works aimed at the identification of HCC biomarkers, in this review we mainly focused on the data published in the last year, with particular attention to the role of (1) molecular and biochemical cellular markers; (2) micro-interfering RNAs; (3) epigenetic variations; and (4) tumor stroma. It is worth mentioning that a significant number of the HCC markers described in the present review may be utilized also as targets for novel therapeutic approaches, indicating the tight relation between diagnosis and therapy. In conclusion, we believe that integrated researches among the different lines of investigation indicated above should represent the winning strategies to identify effective HCC markers and therapeutic targets.

Dissecting the expression of EEF1A1/2 genes in human prostate cancer cells: the potential of EEF1A2 as a hallmark for prostate transformation and progression

Background:In prostate adenocarcinoma, the dissection of the expression behaviour of the eukaryotic elongation factors (eEF1A1/2) has not yet fully elucidated.Methods:The EEF1A1/A2 expressions were investigated by real-time PCR, western blotting (cytoplasmic and cytoskeletal/nuclear-enriched fractions) and immunofluorescence in the androgen-responsive LNCaP and the non-responsive DU-145 and PC-3 cells, displaying a low, moderate and high aggressive phenotype, respectively. Targeted experiments were also conducted in the androgen-responsive 22Rv1, a cell line marking the progression towards androgen-refractory tumour. The non-tumourigenic prostate PZHPV-7 cell line was the control.Results:Compared with PZHPV-7, cancer cells showed no major variations in EEF1A1 mRNA; eEF1A1 protein increased only in cytoskeletal/nuclear fraction. On the contrary, a significant rise of EEF1A2 mRNA and protein were found, with the highest levels detected in LNCaP. Eukaryotic elongation factor 1A2 immunostaining confirmed the western blotting results. Pilot evaluation in archive prostate tissues showed the presence of EEF1A2 mRNA in near all neoplastic and perineoplastic but not in normal samples or in benign adenoma; in contrast, EEF1A1 mRNA was everywhere detectable.Conclusion:Eukaryotic elongation factor 1A2 switch-on, observed in cultured tumour prostate cells and in human prostate tumour samples, may represent a feature of prostate cancer; in contrast, a minor involvement is assigned to EEF1A1. These observations suggest to consider EEF1A2 as a marker for prostate cell transformation and/or possibly as a hallmark of cancer progression.

Effect of unmodified triple helix‐forming oligodeoxyribonucleotide targeted to human multidrug‐resistance gene mdr1 in MDR cancer cells

The human mdr1 gene encodes a transmembrane glycoprotein the over‐expression of which is associated with development of multidrug resistance in human tumor cells. A negative modulation of human mdr1 has been attempted via a 27‐mer unmodified triple helix‐forming oligonucleotide, named 1D, targeted to a homopurine sequence in the coding region of the gene. By administering 10 μM of 1D we could find a significant reduction in MDR1 mRNA levels in the human drug‐resistant cell line CEM‐VLB 100. This effect appears to be specific and due to a transient block of RNA polymerase mediated by triple helix formation.

Improving siRNA bio-distribution and minimizing side effects.

The RNA interference (RNAi) is a biological process by which a double stranded RNA (dsRNA also called small interfering RNA - siRNA) triggers the sequence-dependent degradation of a target RNA within the cellular environment. Thus siRNAs can be used to combat the expression of deleterious gene(s) causing disease or to destroy invading pathogen RNAs. Despite their enormous therapeutic potential, the use of siRNA as drugs presents two major problems: the difficulties to identify optimal delivery systems and the possible induction of different unwanted side effects. In this review, after presenting an overview about the mechanisms ruling the process of RNAi, we focus the attention on the description of the strategies developed to optimise systemic siRNA delivery; in this sense, considerations about the attempts to improve siRNA stability in the biological environment, the development of synthetic vectors for siRNA delivery, the siRNA bio-distribution and pharmacokinetics together with the selection of siRNA targeted delivery systems, are discussed. Since in the optimisation of the siRNA delivery systems the minimization of siRNA side effects should not be neglected, in the last part of the review we consider the problems related to the possible induction of siRNA mediated side effects focusing on the so called microRNA like off-targeting.

Effects of E2F1-cyclin E1-E2 circuit down regulation in hepatocellular carcinoma cells

BACKGROUND No effective therapy is available for hepatocellular carcinoma. To identify novel therapeutic strategies, we explored the effects of the depletion of E2F1, cyclin E1-E2 whose inter-relationships in hepatocellular carcinoma cell proliferation have never been defined. METHODS siRNA-mediated depletion of the targets was studied in the hepatocellular carcinoma cells HepG2, HuH7 and JHH6 characterized by high, medium and low hepatocyte differentiation grade, respectively; a model of normal human hepatocytes was also considered. RESULTS The depletion of each target mRNA reduced the levels of the other two mRNAs, thus demonstrating a close regulatory control, also confirmed by over-expression experiments. At the protein level, an exception to this trend was observed for cyclinE1 whose amount increased upon cyclin E2 (HepG2, HuH7, JHH6) and E2F1 (HepG2) depletion. In HepG2, reduced cyclinE1 proteolysis accounted for this observation. Additionally, cyclin E1-E2-E2F1 targeting decreased the levels of cyclin A2 mRNA and of the hyper-phosphorylated form of pRb thus leading to an S-phase cell decrease; migration was impaired as well. Finally, the model of human hepatocytes used was clearly less affected by target mRNAs depletion than hepatocellular carcinoma cells. CONCLUSION Our data provide novel mutual relationships amongst cyclin E1-E2-E2F1 and indicate their role in sustaining hepatocellular carcinoma cell proliferation/migration, validating the concept of an anti-cyclin E1-E2-E2F1 therapeutic approach for hepatocellular carcinoma.

Interaction of G‐rich GT oligonucleotides with nuclear‐associated eEF1A is correlated with their antiproliferative effect in haematopoietic human cancer cell lines

G‐rich GT oligonucleotides with a different content of G clusters have been evaluated for their ability to exert cytotoxicity and to bind to nuclear‐associated proteins in T‐lymphoblast CCRF‐CEM cells. Only the oligomers that did not form G‐based structures or had a poor structure, under physiological conditions, were able to exert significant cellular growth inhibition effect. The cytotoxicity of these oligomers was related to their binding to the nuclear‐associated eEF1A protein, but not to the recognition of nucleolin or other proteins. In particular, GT oligomers adopting a conformation compatible with G‐quadruplex, did not exert cytotoxicity and did not bind to eEF1A. The overall results suggest that the ability of oligomers to adopt a G‐quadruplex‐type secondary structure in a physiological buffer containing 150 mm NaCl is not a prerequisite for antiproliferative effect in haematopoietic cancer cells. The cytotoxicity of G‐rich GT oligomers was shown to be tightly related to their binding affinity for eEF1A protein.

Bortezomib effect on E2F and cyclin family members in human hepatocellular carcinoma cell lines

AIM To evaluate the effects of the proteasome inhibitor bortezomib (BZB) on E2Fs and related genes in hepatocellular carcinoma (HCC) cells. METHODS The mRNA levels of the E2F family members (pro-proliferative: E2F1-3 and anti-proliferative: E2F4-8) and of their related genes cyclins and cyclin-dependent kinases (cdks) were evaluated in two HCC cell lines following a single BZB administration. mRNA levels of the epithelial-mesenchymal transition (EMT) genes were also measured in both cell lines after BZB treatment. The BZB concentration (40 nmol/L) used was chosen to stay well below the maximal amount/cm² recommended for in vivo application, and 2 d incubation was chosen as this time point has been found optimal to detect BZB effects in our previous studies. The HCC cell lines, HepG2 and JHH6, were chosen as they display different phenotypes, hepatocyte-like for HepG2 and undifferentiated for JHH6, thus representing an in vitro model of low and high aggressive forms of HCC, respectively. The mRNA levels of the target genes were measured by two-color microarray-based gene expression analysis, performed according to Agilent Technologies protocol and using an Agilent Scan B. For the E2F family members, mRNA levels were quantified by real-time reverse transcription polymerase chain reaction (RT-PCR). Using small interfering RNAs, the effects of E2F8 depletion on cell number was also evaluated. RESULTS After BZB treatment, microarray analysis of the undifferentiated JHH6 revealed a significant decrease in the expression of the pro-proliferative E2F member E2F2. Quantitative RT-PCR data were in keeping with the microarray analysis, and showed a significant increase and decrease in E2F8 and E2F2 mRNA levels, respectively. In contrast, BZB treatment of the hepatocyte-like HCC cell line HepG2 had a significant impact on mRNA levels of 5 of the 8 E2F members. In particular, mRNA levels of the pro-proliferative E2F members E2F1, E2F2, and of the anti-proliferative member E2F8, decreased over 80%. Notably, a reduction in E2F8 expression in HepG2 and JHH6 cells following siRNA treatment had no impact on cell proliferation. As observed with JHH6, BZB treatment of HepG2 cells induced a significant increase in mRNA levels of an anti-proliferative E2F member, E2F6 in this case. As was observed with E2Fs, more dramatic changes in mRNA levels of the E2F related genes cyclins and Cdks and EMT genes were observed after BZB treatment of HepG2 compared to JHH6. CONCLUSION The differential expression of E2Fs and related genes induced by BZB in diverse HCC cell phenotypes contribute to bortezomibs mechanism of action in hepatocellular carcinoma.

Therapeutic Potential of Nucleic Acid-Based Drugs in Coronary Hyper- Proliferative Vascular Diseases

The thickening of the vessel wall (intimal hyperplasia) is a pathological process which often follows revascularization approaches such as transluminal angioplasty and artery bypass graft, procedures used to re-vascularize stenotic artery. Despite the significant improvements in the treatment of intimal hyperplasia obtained in the last years, the problem has not completely solved. Nucleic acid based-drugs (NABDs) represent an emergent class of molecules with potential therapeutic value for the treatment of intimal hyperplasia. NABDs of interest in the field of intimal hyperplasia are: ribozymes, DNAzymes, antisense oligonucleotides, decoy oligonucleotides, small interfering RNAs and micro interfering RNAs. These molecules can recognize, in a sequencespecific fashion, a target which, depending on the different NABDs, can be represented by a nucleic acid or a protein. Upon binding, NABDs can down-modulate the functions of the target (mRNA/proteins) and thus they are used to impair the functions of disease-causing biological molecules.In spite of the great therapeutic potential demonstrated by NABDs in many experimental model of intima hyperplasia, their practical use is hindered by the necessity to identify optimal delivery systems to the vasculature. In the first part of this review a brief description of the clinical problem related to intima hyperplasia formation after revascularization procedures is reported. In the second part, the attention is focused on the experimental evidences of NABD therapeutic potential in the prevention of intimal hyperplasia. Finally, in the third part, we will describe the strategies developed to optimize NABD delivery to the diseased vessel.