Expression profiles in surgically-induced carotid stenosis: a combined transcriptomic and proteomic investigation

Vascular injury aimed at stenosis removal induces local reactions often leading to restenosis. The aim of this study was a concerted transcriptomic-proteomics analysis of molecular variations in a model of rat carotid arteriotomy, to dissect the molecular pathways triggered by vascular surgical injury and to identify new potential anti-restenosis targets. RNA and proteins extracted from inbred Wistar Kyoro (WKY) rat carotids harvested 4 hrs, 48 hrs and 7 days after arteriotomy were analysed by Affymetrix rat microarrays and by bidimensional electrophoresis followed by liquid chromatography and tandem mass spectrometry, using as reference the RNA and the proteins extracted from uninjured rat carotids. Results were classified according to their biological function, and the most significant Kyoro Encyclopedia of Genes and Genomes (KEGG) pathways were identified. A total of 1163 mRNAs were differentially regulated in arteriotomy-injured carotids 4 hrs, 48 hrs and 7 days after injury (P < 0.0001, fold-change > or =2), while 48 spots exhibited significant changes after carotid arteriotomy (P < 0.05, fold-change > or =2). Among them, 16 spots were successfully identified and resulted to correspond to a set of 19 proteins. mRNAs were mainly involved in signal transduction, oxidative stress/inflammation and remodelling, including many new potential targets for limitation of surgically induced (re)stenosis (e.g. Arginase I, Kruppel like factors). Proteome analysis confirmed and extended the microrarray data, revealing time-dependent post-translational modifications of Hsp27, haptoglobin and contrapsin-like protease inhibitor 6, and the differential expression of proteins mainly involved in contractility. Transcriptomic and proteomic methods revealed functional categories with different preferences, related to the experimental sensitivity and to mechanisms of regulation. The comparative analysis revealed correlation between transcriptional and translational expression for 47% of identified proteins. Exceptions from this correlation confirm the complementarities of these approaches.

Pathophysiology of stem cells in restenosis

Recent evidence has shown that vascular function depends not only on cells within the vessels, but is also significantly modulated by circulating cells derived from the bone marrow. A number of studies indicate that an early reendothelialization by circulating endothelial precursors after vascular injury prevents excessive cell proliferation and restenosis. Conversely, other studies concluded that the homing of other cell fractions, consisting mainly of smooth muscle precursors, cause pathological remodelling. Different cell types have been identified and characterized so far as circulating precursors able to participate in vascular repair by homing and differentiating towards endothelial cells or smooth muscle cells. Among these, endothelial precursor cells, smooth muscle progenitor cells, mesenchymal stem cells and others have been described. The origins, the hierarchy, the role and the markers of these different cell populations are still controversial. Nevertheless, different strategies have been developed so far in animal models to induce the mobilization and the recruitment of stem cells to the injury site, based on physical training, hormone injection and application of stem cell-capturing coated stents. It should also be mentioned that the limited data currently available derived from clinical trials provide contrasting results about the effective role of vascular cell precursors in restenosis prevention, thus indicating that conclusions derived from studies in animal models cannot always be directly applied to humans and that caution should be used in the manipulation of circulating progenitor cells for therapeutic strategies.

Comparative evaluation of different DNA extraction procedures from food samples

Five methodologies for extracting DNA from food samples are described. The food products analyzed are from either soybean or maize. They were selected on the basis of the mechanical, thermal, and chemical treatments that they had been subjected to during industrial processing. DNA preparations were evaluated for purity, yield, and average fragment size. Two endogenous genes, soybean lectin gene and alcohol dehydrogenase gene (adh1), were used to assess the degree of DNA degradation at different stages of the transformation chain. The goal of this study was to determine the role that extraction methods play in DNA amplification in order to select the best protocol for a food sample. This comparative evaluation can be specifically useful for detection of genetically modified ingredients in a variety of food matrices.

RB and RB2/p130 genes demonstrate both specific and overlapping functions during the early steps of in vitro neural differentiation of marrow stromal stem cells

Marrow stromal stem cells (MSCs) are stem-like cells that are currently being tested for their potential use in cell therapy for a number of human diseases. MSCs can differentiate into both mesenchymal and nonmesenchymal lineages. In fact, in addition to bone, cartilage and fat, it has been demonstrated that MSCs are capable of differentiating into neurons and astrocytes. RB and RB2/p130 genes are involved in the differentiation of several systems. For this reason, we evaluated the role of RB and RB2/p130 in the differentiation and apoptosis of MSCs under experimental conditions that allow for MSC differentiation toward the neuron-like phenotype. To this end, we ectopically expressed either RB or RB2/p130 and monitored proliferation, differentiation and apoptosis in rat primary MSC cultures induced to differentiate toward the neuron-like phenotype. Both RB and RB2/P130 decreased cell proliferation rate. In pRb-overexpressing cells, the arrest of cell growth was also observed in the presence of the HDAC-inhibitor TSA, suggesting that its antiproliferative activity does not rely upon the HDAC pathway, while the addition of TSA to pRb2/p130-overexpressing cells relieved growth inhibition. TUNEL reactions and studies on the expression of genes belonging to the Bcl-2 family showed that while RB protected differentiating MSCs from apoptosis, RB2/p130 induced an increase of apoptosis compared to controls. The effects of both RB and RB2/p130 on programmed cell death appeared to be HDAC- independent. Molecular analysis of neural differentiation markers and immunocytochemistry revealed that RB2/p130 contributes mainly to the induction of generic neural properties and RB triggers cholinergic differentiation. Moreover, the differentiation potentials of RB2/p130 and RB appear to rely, at least in part, on the activity of HDACs.

Methods to improve the yield and quality of DNA from dried and processed figs

We describe here a molecular method that can be used to detect genome traits of a given horticultural item at each stage from the farm to the market. We developed a procedure to extract and amplify by PCR DNA obtained from complex matrixes, such as dried figs and fig jam. Few fragmented DNA molecules can be recovered from food products. However, we were able to increase the yield of PCR reactions by successfully applying an enzymatic repair protocol to retrieved DNA.

Small interfering RNAs and antisense oligonucleotides for treatment of neurological diseases

The complexity of the central nervous system (CNS) exposes it to a number of different diseases, often caused by only small variations in gene sequence or expression level. Antisense oligonucleotides and RNA interference-mediated therapies hold great promise for the treatment of CNS diseases in which neurodegeneration is linked to overproduction of endogenous protein or to synthesis of aberrant proteins coded by dominant mutant alleles. Nevertheless, difficulties related to the crossing of the blood-brain barrier, expression vectors, molecule design and to the choosing of the correct target, should be effectively solved. This review summarizes some of the most recent findings concerning the administration of potential nucleic acid-based therapeutic drugs, as well as the most promising studies performed both in vitro and in animal models of disease. Finally, some current clinical trials involving antisense oligonucleotides or silencing RNA for therapy of neurological disorders are illustrated. Results of current studies and clinical trials are exciting, and further results will be certainly reached with increasing knowledge of blood-brain barrier transporters, of genes involved in neurological disease and in new vectors for efficient delivery to brain.

Clinical trials of a new class of therapeutic agents: antisense oligonucleotides

Antisense oligodeoxynucleotides (ODNs) are short stretches of DNA complementary to a target mRNA. The ODNs selectively hybridise to their complementary RNA by Watson-Crick base pairing rules. In theory, the use of antisense ODNs provides a method to specifically inhibit the intracellular expression of any disorder whose genetic aetiology is well known. For this reason, researchers thought that if antisense drugs proved to be so specific there would be no side effects. However, toxicity-related problems arose in initial animal studies of antisense drugs in the early 1990s and since then companies have been using these compounds cautiously. In order to be useful therapeutically, an ODN must (a) exhibit reasonable stability in the physiological environment, (b) be taken up and retained in adequate quantities by the target cells, (c) specifically bind target mRNA with high affinity, (d) have an acceptable therapeutic ratio, free of unwanted toxic and non-specific side effects and (e) be easily synthesised in sufficient quantities to allow clinical use. Most of these criteria have already been met by ODNs recently used in this way. This review describes certain therapeutic applications of antisense techniques currently under investigation in oncology, haematopathology and inflammatory diseases.

EGF-responsive rat neural stem cells: molecular follow-up of neuron and astrocyte differentiation in vitro

Neural stem cells (NSCs) could be very useful for the "cell therapy" treatment of neurological disorders. For this reason basic studies aiming to well characterize the biology of NSCs are of great interest. We carried out a molecular and immunocytochemical analysis of EGF-responsive NSCs obtained from rat pups. After the initial growth of NSCs as floating neurospheres in EGF-containing medium, cells were plated on poly-L-ornithine-coated dishes either in the presence or absence of EGF. We followed cell differentiation and apoptosis for 21 days in vitro and analyzed the expression levels of some genes having a major role in these processes, such as pRB, pRB2/p130, p27, and p53. We observed that EGF impairs neuronal differentiation. Furthermore, in the absence of mitogens, apoptosis, which appeared to proceed through the "p53 network," was significantly lower than in the presence of EGF. The cyclin kinase inhibitor p27, while important for cell cycle exit, seemed dispensable for cell survival and differentiation.

Surgical injury of rat arteries: genetic control of the remodelling process

OBJECTIVES

Remodelling and restenosis are complex biological processes responsible for bypass and percutaneous transluminal coronary angioplasty failures which are likely to affect many hundreds of genes. We evaluated the effectiveness of topically applied antisense oligonucleotides in reducing the translation of the messenger RNA for the transcription factor c-myc and in reducing stenosis.

METHODS

Surgery was performed under sterile conditions; 60 Wistar-Kyoto male rats were anaesthetized by ketamine. The carotid arteries were isolated through a median incision in the anterior neck region. At the same point, 0.5 mm longitudinal incisions were performed. Haemostasis was obtained by an adventitial 8.0 stitch. Thirty animals were given 150 microg of c-myc antisense oligonucleotide (Group A) while the other 30 animals received 150 microg of c-myc control sense oligonucleotide (Group B). Oligo molecules were locally applied through 100 microl of 20% pluronic gel. Rats were sacrificed at 30 days; carotid arteries were explanted and stained. Qualitative histological analysis was performed in all cases; serial sections were made every 25 micro in seven consecutive rats for each group. Morphometric analysis was also performed, luminal and medial area values recorded and the ratio between the two areas calculated. Data from each animal were compared with the corresponding contralateral carotid artery and expressed as mean+/-standard deviation. Statistical comparison between the two groups was carried out by one-way ANOVA text.

RESULTS

Qualitative histological analysis showed marked remodelling with complete disarray of vessel wall, neointima accumulation and evidence of elastic fibres in the adventitia of all animals of Group B versus Group A. Morphometric analysis showed a significant reduction in the lumen area in Group A animals together with increased values of the medial area versus Group B animals. In addition, the ratio between the lumen and medial area was significantly higher in Group A than in Group B (2.61+/-0.18 versus 1.14+/-0.33, P<0.0001).

CONCLUSIONS

c-myc antisense oligonucleotides applied intraoperatively can reduce post-operative stenosis.

Gene expression and morphological changes in surgically injured carotids of spontaneously hypertensive rats

The expression profiles of genes involved in cell proliferation, differentiation and programmed death were investigated in carotids of spontaneously hypertensive rats (SHR) treated with a model of surgical injury that mimics events occurring during arterial grafts, endarterectomy and organ transplantation. The mRNA level of the c-myc, angiotensin II receptor 1 (AT1), Rb/p105, Rb2/p130, Bcl-2 and Bax-alpha genes was assessed by a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) technique at different times up to 48 h after injury, while the morphological changes were evaluated 30 days after injury. The proliferation marker c-myc increases almost immediately, peaks after 4 h and returns to basal levels after 24 h; the AT1 receptor mRNA reaches its maximal level 48 h after injury. The level of cell cycle exit markers Rb/p105 and Rb2/p130 gradually decreases after injury. The apoptosis marker Bcl-2/Bax-alpha ratio shows a significant reduction only 4 h after injury, resuming the initial value after 24 and 48 h. Morphological analysis reveals that surgical injury in SHR induces adventitial and medial constrictive remodeling changes rather than intima proliferation as in balloon angioplasty. Both molecular and histological data show substantial differences with respect to normotensive rats.

RB2/p130 ectopic gene expression in neuroblastoma stem cells: evidence of cell-fate restriction and induction of differentiation

The activity of the RB2/p130 gene, which is a member of the retinoblastoma gene family, is cell-cycle-regulated and plays a key role in growth inhibition and differentiation. We used neuroblastoma cell lines as a model for studies on neural crest progenitor cell differentiation. We show that Rb2/p130 ectopic protein expression induces morphological and molecular modifications, promoting differentiation of intermediate (I) phenotype SK-N-BE(2)-C neuroblastoma cells towards a neuroblastic (N) rather than a Schwann/glial/melanocytic (S) phenotype. These modifications are stable as they persist even after treatment with an S-phenotype inducer. Rb2/p130 ectopic expression also induces a more differentiated phenotype in N-type SH-SY-5Y cells. Further, this function appears to be independent of cell-cycle withdrawal. The data reported suggest that the Rb2/p130 protein is able to induce neuronal lineage specification and differentiation in neural crest stem and committed neuroblastoma cells, respectively. Thus, the Rb2/p130 protein seems to be required throughout the full neural maturation process.

pRb2/p130 gene overexpression induces astrocyte differentiation

There are many data on the activity of the RB gene in neural differentiation and apoptosis, but the role of pRb2/p130 in neuronal and glial maturation has been far less investigated. To elucidate the role of pRb2/p130 in astrocyte development we overexpressed this protein in astrocytoma and normal astrocyte cultures by adenoviral-mediated gene transfer. In astrocytoma cells, p130/RB2 overexpression resulted in a significant reduction of cell growth and in an increased G(0)/G(1) cell population. We did not observe any induction of programmed cell death as determined by TUNEL reaction. Interestingly, pRb2/p130 overexpression induced astrocyte differentiation. Astrocyte cell cycle arrest and differentiation seemed to proceed through a way distinct from the p53 pathway.

Molecular analysis of arterial stenosis in rat carotids

A new model of surgical injury for the induction and development of stenosis in common rat carotids is described. This model differs from balloon angioplasty or vein graft systems currently applied on animals to develop stenosis, since it involves the entire vessel wall layers and mimics the injury occurring during arterial grafts, endarterectomy or organ transplantation. At different times following arterial damage, the pattern of expression of genes already known to be involved in the proliferation, differentiation, and apoptosis of smooth muscle cells (c-myc, Angiotensin II receptor 1, Bcl-2 and Bax alpha), as well as of Rb and Rb2 genes, whose pattern of expression after arterial injury has not yet been reported, was analyzed by semi-quantitative reverse transcription-polymerase chain reaction technique. Histological and histochemical analysis on carotid sections shows the morphological changes which occurred 30 days after surgical injury in the vessel wall. Molecular and histological data demonstrate that this model of surgical injury induces neointimal proliferation in about 30% of rats. In about 70% of the remaining rats, it induces the processes responsible for negative remodelling, namely the significant accumulation of extracellular matrix and fibers and disorganization of arterial tunics. This model is therefore available for further studies on the expression of genes involved in the arterial stenotic process, as well as for testing drugs aimed at limiting this recurrent pathophysiological phenomenon.

Serum tumour necrosis factor-alpha levels in cancer patients are discontinuous and correlate with weight loss

BACKGROUND

Tumour necrosis factor-alpha (TNF) has been regarded as a potential mediator of cancer cachexia. Assessment of TNF circulating levels in cancer patients and their correlation with weight loss has led to controversial results.

MATERIALS AND METHODS

We measured TNF circulating levels in 28 patients with gastrointestinal cancer and 29 controls with benign gastrointestinal diseases at different times (08.00 h, 14.00 h, 20.00 h) before operation.

RESULTS

TNF activity was not detected in any of controls at any times. In cancer patients, TNF circulating levels were detectable in 18 cases (64.3%) and appeared to be discontinuous. TNF levels above the limit of detection were present in 15 patients (53.6%) at 08.00 h, in 14 (50%) at 014.00 h and in nine (32.1%) at 20.00 h. Mean TNF levels were 14.3 +/- 4 pg mL(-1) at 08.00 h, 16.7 +/- 4.6 pg mL(-1) at 14.00 h (P = 0.05) and 18.5 +/- 10.2 pg mL(-1) at 20.00 h (P < 0.05 vs. 08.00 h and 14.00 h). According to Spearman's analysis, the sum of TNF concentrations at the three times significantly correlated with the severity of weight loss (Spearman's correlation coefficient = - 0.420; P = 0.026). TNF concentrations were consistently and significantly higher in patients with severe weight loss than in those with moderate or light weight loss at 08.00 h (26.3 +/- 8.3, 8.9 +/- 4.2, 3.8 +/- 2.1, respectively; P = 0.04 at one-way ANOVA). TNF levels were higher in anorectic than in nonanorectic patients at any hour, but the differences were not statistically significant.

CONCLUSIONS

The present study demonstrates that TNF is intermittently or discontinuously detectable in patients with gastrointestinal cancer and that its levels correlate with the severity of weight loss.

[Pathogenetic and therapeutic aspects of secondary anorexia]

Anorexia is an often underrated symptom in the clinical management of patients suffering from chronic diseases. Moreover, the anorexia accompanying chronic diseases (secondary anorexia) is often confused with anorexia nervosa, a typically neuropsychiatric disorder involving completely different pathogenic mechanisms and therapeutic strategies. Secondary anorexia is one of the main factors responsible for the development of malnutrition, which in turn negatively affects patient morbidity and mortality. Different mechanisms have been proposed to explain the pathogenesis of secondary anorexia. However, consistent experimental and clinical evidence seems to point to hypothalamic serotonergic system hyperactivity as a preeminent cause; this hyperactivity appears to be triggered by enhanced brain availability of tryptophan, the aminoacid precursor of serotonin. The hyperactive hypothalamic serotonergic system might also represent the final effector where different regulatory and modulating pathways, including cytokines, converge. The involvement of tryptophan and the hypothalamic serotonergic system is further supported by the effectiveness of a therapeutic strategy, based on the inhibition of tryptophan entry into the brain, in increasing the food intake of anorectic patients. Although these results represent an encouraging approach to the treatment of secondary anorexia, with possible beneficial effects on the nutritional status of patients, they need to be validated in larger trials.

Effect of cisplatin and paclitaxel on plasma free tryptophan levels. An in vitro study

Emesis is a common side effect of some antineoplastic drugs. Cisplatin (CP) induces a biphasic pattern of emesis referred to as acute (AE) and delayed (DE) emesis. The serotonergic system plays a major role in the pathogenesis of CP-induced AE, as suggested by the therapeutic efficacy of 5HT3 receptor antagonists. The pathogenesis of CP-induced DE are not clear. To date, there are no pharmacological agents which satisfactorily control DE. We hypothesize that increased availability of tryptophan (TRP) for the synthesis of brain serotonin (5-HT) could, at least in part, contribute to CP-induced DE. In fact, within 2-4 hrs of administration, CP is largely bound to albumin (ALB) with consequent possible displacement of TRP which circulates in plasma mostly (90% of total plasma TRP) bound to its natural carrier, ALB. To test this hypothesis, we studied in vitro the effect of increasing doses of cisplatin on F-TRP in plasma obtained from healthy volunteers. We also tested the effects of therapeutic amounts of paclitaxel, an antineoplastc agent which does not cause emesis.

RESULTS

F-TRP concentrations increased in a dose-dependent manner following incubation with cisplatin, in contrast to paclitaxel (PTX).

CONCLUSIONS

The preliminary data obtained suggest that CP, but not PTX, at therapeutic doses, increases plasma F-TRP concentrations. This increase has likely negligible relevance in CP-induced AE, which is induced by the 5-HT released by the enterochromaffin cell system, while it might play a role in the pathogenesis of CP-induced DE. In fact, CP binding to ALB is stable for 4-5 days following administration, thus suggesting long-term TRP displacement from ALB and enhanced brain 5-HT synthesis and release. Whether increased TRP availability for 5-HT synthesis might be the pathogenic mechanism for CP-induced DE in vivo, is currently being tested.

Detection of DNA in ancient bones using histochemical methods

We describe histochemical techniques for detecting DNA within the osteocytic lacunae of ancient bones. The bones examined were fragments of femurs from two human individuals found in the Pompeian C. I. Polybius house and fragments of metacarpals from two horses (Equus sp.) found in the Pompeian "Casti Amanti" house. Both buildings were buried by the 79 A. D. Vesuvius eruption. Fragments of femurs from a modern horse, a modern swine and a modern amphibian also were studied as controls. Some bone sections were stained with two different DNA-specific fluorochromes, 4'-'6-diamidino-2-phenylindole (DAPI) and chromomycin A3 (CMA), while others were stained by the Feulgen reaction. All of the techniques gave a positive reaction within the osteocytic lacunae. Histological analysis of the undecalcified, ground and unstained sections agreed well with results of bone sections stained with either the fluorochromes or the Feulgen reaction. Bones showing good histology also were positive by our DNA-specific stain. Histochemical and histological analyses correlated well with the success of DNA extraction and amplification. Using conventional DNA-specific histochemical techniques in conjunction with histological analysis can be useful in the study of DNA extracted from ancient bone remains while reducing both the amount of time and cost.

In vivo effects of partial phosphorothioated AT1 receptor antisense oligonucleotides in spontaneously hypertensive and normotensive rats

Partial phosphorothioate (PS) antisense oligodeoxynucleotides (ODNs) targeted against rat AT1 receptor mRNA have been used to control blood pressure in normotensive (WKY) and spontaneously hypertensive (SHR) rats. Molecules were injected intracerebroventricularly (i.c.v., right lateral ventricle) in freely moving animals. The antisense ODN lowered the mean arterial pressure (MAP) 24 hours (-43 mmHg+/-10) and 48 hours (-30 mmHg+/-13) after injection, while the control ODN molecule had no significant effects. The observed decrease of blood pressure was due to a specific inhibition of AT1 receptor gene expression, since the level of its mRNA, monitored by reverse transcription (RT)- polymerase chain reaction (PCR), was significantly reduced by antisense molecule (-40%), compared to sense one. In normotensive rats no effect on MAP have been observed, while AT1 receptor gene expression is reduced (-40%) by antisense treatment. It is known that SHRs have an enhanced basal activity of the central renin-angiotensin system that induces an increase in central sympathetic outflow. Instead in WKY rats the central sympathetic outflow is not conditioned by the enhanced activity of brain renin-angiotensin system. Therefore in normotensive rats although partial PS ODN reduces the AT1 mRNA level this will not result in a modification of the sympathetic outflow and no change in MAP level would be observed.

Antisense oligonucleotides as therapeutic agents

Antisense oligonucleotides can block the expression of specific target genes involved in the development of human diseases. Therapeutic applications of antisense techniques are currently under investigation in many different fields. The use of antisense molecules to modify gene expression is variable in its efficacy and reliability, raising objections about their use as therapeutic agents. However, preliminary results of several clinical studies demonstrated the safety and to some extent the efficacy of antisense oligodeoxynucleotides (ODNs) in patients with malignant diseases. Clinical response was observed in some patients suffering from ovarian cancer who were treated with antisense targeted against the gene encoding for the protein kinase C-alpha. Some hematological diseases treated with antisense oligos targeted against the bcr/abl and the bcl2 mRNAs have shown promising clinical response. Antisense therapy has been useful in the treatment of cardiovascular disorders such as restenosis after angioplasty, vascular bypass graft occlusion, and transplant coronary vasculopathy. Antisense oligonucleotides also have shown promise as antiviral agents. Several investigators are performing trials with oligonucleotides targeted against the human immunodeficiency virus-1 (HIV-1) and hepatitis viruses. Phosphorothioate ODNs now have reached phase I and II in clinical trials for the treatment of cancer and viral infections, so far demonstrating an acceptable safety and pharmacokinetic profile for continuing their development. The new drug Vitravene, based on a phosphorothioate oligonucleotide designed to inhibit the human cytomegalovirus (CMV), promises that some substantial successes can be reached with the antisense technique.

Antisense oligonucleotides as therapeutic agents

Antisense oligonucleotides can block the expression of specific target genes involved in the development of human diseases. Therapeutic applications of antisense techniques are currently under investigation in many different fields. The use of antisense molecules to modify gene expression is variable in its efficacy and reliability, raising objections about their use as therapeutic agents. However, preliminary results of several clinical studies demonstrated the safety and to some extent the efficacy of antisense oligodeoxynucleotides (ODNs) in patients with malignant diseases. Clinical response was observed in some patients suffering from ovarian cancer who were treated with antisense targeted against the gene encoding for the protein kinase C-alpha. Some hematological diseases treated with antisense oligos targeted against the bcr/abl and the bcl2 mRNAs have shown promising clinical response. Antisense therapy has been useful in the treatment of cardiovascular disorders such as restenosis after angioplasty, vascular bypass graft occlusion, and transplant coronary vasculopathy. Antisense oligonucleotides also have shown promise as antiviral agents. Several investigators are performing trials with oligonucleotides targeted against the human immunodeficiency virus-1 (HIV-1) and hepatitis viruses. Phosphorothioate ODNs now have reached phase I and II in clinical trials for the treatment of cancer and viral infections, so far demonstrating an acceptable safety and pharmacokinetic profile for continuing their development. The new drug Vitravene, based on a phosphorothioate oligonucleotide designed to inhibit the human cytomegalovirus (CMV), promises that some substantial successes can be reached with the antisense technique.

Histological analysis and ancient DNA amplification of human bone remains found in caius iulius polybius house in pompeii

Thirteen skeletons found in the Caius Iulius Polybius house, which has been the object of intensive study since its discovery in Pompeii 250 years ago, have provided an opportunity to study either bone diagenesis by histological investigation or ancient DNA by polymerase chain reaction analysis. DNA analysis was done by amplifying both X- and Y-chromosomes amelogenin loci and Y-specific alphoid repeat locus. The von Willebrand factor (vWF) microsatellite locus on chromosome 12 was also analyzed for personal identification in two individuals showing alleles with 10/11 and 12/12 TCTA repeats, respectively. Technical problems were the scarcity of DNA content from osteocytes, DNA molecule fragmentation, microbial contamination which change bone structure, contaminating human DNA which results from mishandling, and frequent presence of Taq DNA polymerase inhibiting molecules like polyphenols and heavy metals. The results suggest that the remains contain endogenous human DNA that can be amplified and analyzed. The amplifiability of DNA corresponds to the bone preservation and dynamics of the burial conditions subsequent to the 79 A.D. eruption.

Induction of apoptosis and differentiation in neuroblastoma and astrocytoma cells by the overexpression of Bin1, a novel Myc interacting protein

Bin1 is a novel protein that specifically binds Myc and inhibits, at least in part, Myc transactivation. Bin1 seems to play a role in cell cycle control, acting as a tumor suppressor gene. Since MYC family genes play a regulatory role in the proliferation, differentiation, and apoptosis of the nervous system, we studied the effects of the overexpression of the Myc-interacting protein, Bin1, in neuroblastoma and astrocytoma cell lines, which were chosen as neural cell system models. The major effects of BIN1 overexpression observed in undifferentiated neuroblastoma and astrocytoma cells were a significant reduction of cell growth, an increase in the G(0)/G(1) cell population and the induction of apoptosis. The trigger of programmed cell death by Bin1 is described for the first time. Bin1 overexpression in undifferentiated cells did not induce any maturation process as neither neuronal nor astrocyte differentiation markers were upregulated in neuroblastoma and astrocytoma cells, respectively. On the other side, the effects of Bin1 overproduction in neuroblastoma and astrocytoma cells committed towards neuronal and astrocyte differentiation, respectively, were different from those observed in undifferentiated cells. Although we did not evidence any triggering of programmed cell death, we did notice a further induction towards more differentiated phenotypes. Our studies suggest that Bin1 overexpression in neuroblastoma and astrocytoma cells can result in one of the following pathways: (1) suppressed cell proliferation, (2) induced differentiation, or (3) apoptosis. Thus, it appears that Bin1 operates through different pathways that involve activation of different genes: the chosen pathway however will depend on the proliferating or differentiated state of the cell.

Antisense inhibitory effect: a comparison between 3'-partial and full phosphorothioate antisense oligonucleotides

Phosphorothioate (PS) antisense oligonucleotides are currently used to inhibit many cell functions both in vivo and in vitro. However, these modified oligos provide reasonable sequence specificity only within a narrow concentration range. To overcome such a limitation we synthesized antisense oligomers, partially phosphorothioated, targeted against the human N-myc mRNA. We utilized such modified oligomers in a human neuroblastoma cell line where the N-myc gene expression was very high, and compared them to full phosphorothioate oligonucleotides. Both full PS and partial PS antisense oligos produced a maximum reduction in target mRNA after 6 h of treatment. They were able to maintain a good level of inhibition for 20 h only at high concentration. While partial PS oligos produced a dose dependent and sequence specific inhibition of N-myc mRNA, full PS molecules suffer from some disadvantages at the highest concentration used. Our results showed that partial PS molecules were capable of reducing gene expression showing a greater sequence specificity over a far broader concentration range. For this reason we conclude that partial PS antisense oligos, with respect to full PS antisense oligos, might be particularly useful for studying gene function.

Differentiation and apoptosis of neuroblastoma cells: role of N-myc gene product

To clarify the role and function of the N-myc product in cell differentiation and apoptosis, we used the antisense oligonucleotide technique to inhibit N-myc gene expression in neuroblastoma cells with different phenotypes: intermediate (I) and neuronal (N), or Schwann-glia (S), respectively. The results suggest that N-myc operates along different pathways. Inhibiting N-myc gene expression either results in suppression of cell proliferation or in induction of differentiation and/or apoptosis.

Plasma amino acid concentrations in patients with acute myelogenous leukemia

Changes in plasma-free amino acid (PFAA) concentrations in the presence of solid tumors have been widely described. Conversely, the PFAA profile in patients with acute leukemias is less well defined. The aim of the present study was to clarify whether the PFAA profile is altered in patients with acute myeloid leukemia (AML), whether the profile differs from the PFAA profile of solid tumors, and whether it may predict outcome of AML. Fasting PFAA were measured in 40 untreated, normally nourished patients with AML (17 males, 23 females), ages 22-78 y, with white blood cell (WBC) counts ranging from 1.08 to 276.5 x 10(3)/cm2, and in 24 healthy volunteers. Plasma concentrations (mu mol/L, mean +/- SE) of glutamic acid (GLU), free tryptophan (FTRP), ornithine (ORN), and glycine (GLY) were significantly higher in AML (GLU: 90.2 +/- 6.1 versus 37 +/- 8; FTRP: 7.0 +/- 0.6 versus 4.8 +/- 0.3, P < 0.005; ORN: 108.7 +/- 5.8 versus 78 +/- 6, P < 0.001; GLY: 295.0 +/- 14.8 versus 239 +/- 9, P < 0.01), whereas serine (SER), methionine (MET), and taurine (TAU) were significantly lower in AML than in controls (SER: 109.0 +/- 5.8 versus 130 +/- 4, P < 0.03; MET: 25.5 +/- 1.3 versus 33 +/- 3, P < 0.03; TAU: 46.5 +/- 3.5 versus 81 +/- 2, P < 0.001), and tended to be even lower in patients who had not responded to chemotherapy or had relapsed within 18 mo of enrollment. Such changes were unrelated to age, sex, and WBC count. Changes in PFAA that occur in AML are only in part similar to those observed in solid tumors. The reduction of TAU appears to be a typical feature of AML and might be secondary to the deficiency of its precursors SER and MET. Further studies are under way aimed at clarifying whether PFAA might predict prognosis in AML, whether PFAA is normalized by remission induction, and if its correction may be of any benefit for patients with hematologic malignancies.

Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients

OBJECTIVE

In obese patients, brain serotonergic stimulation via orally administered 5-hydroxy-tryptophan (5-HTP), the precursor of serotonin, causes decreased carbohydrate intake and weight loss. Since diabetes mellitus is associated with depressed brain serotonin, hyperphagia and carbohydrate craving, we hypothesized that in diabetic patients, orally administered 5-HTP stimulates brain serotonergic activity and thus normalizes eating behaviour. To test this hypothesis, we investigated whether in diabetic patients: 1) predicted brain serotonin concentrations are depressed as a result of decreased availability of the precursor, tryptophan; and 2) oral 5-HTP is effective in reducing energy and carbohydrate intake.

SUBJECTS AND METHODS

25 overweight non-insulin dependent diabetic outpatients were enrolled in a double-blind, placebo-controlled study, and randomized to receive either 5-HTP (750 mg/d) or placebo for two consecutive weeks, during which no dietary restriction was prescribed. Energy intake and eating behaviour, as expressed by macronutrient selection, were evaluated using a daily diet diary. Plasma amino acid concentrations and body weight, as well as serum glucose, insulin and glycosylated haemoglobin were assessed.

RESULTS

20 patients (nine from the 5-HTP group and 11 from the Placebo group) completed the study. Brain tryptophan availability in diabetic patients was significantly reduced when compared to a group of healthy controls. Patients receiving 5-HTP significantly decreased their daily energy intake, by reducing carbohydrate and fat intake, and reduced their body weight.

CONCLUSIONS

These data confirm the role of the serotonergic system in reducing energy intake, by predominantly inhibiting carbohydrate intake, and suggest that 5-HTP may be safely utilized to improve the compliance to dietary prescriptions in non-insulin dependent diabetes mellitus.

Ancient DNA in human bone remains from Pompeii archaeological site

aDNA extraction and amplification procedures have been optimized for Pompeian human bone remains whose diagenesis has been determined by histological analysis. Single copy genes amplification (X and Y amelogenin loci and Y specific alphoid repeat sequences) have been performed and compared with anthropometric data on sexing.

Antisense oligonucleotides and myotonin gene expression in C2 mouse cells

By describing the behavior of myotonin mRNA levels, from the quiescent to the differentiated state in C2 mouse myoblasts, we produced evidence bearing on the role of myotonin gene product in the control of cell growth and differentiation. To study the role of myotonin in myotonic dystrophy (DM) pathogenesis, we developed a suitable cellular model where myotonin gene expression was modulated by phosphorothioate antisense oligonucleotides in C2 cultured cells. Furthermore, an isoform of the gene product, similar to that described in humans and not yet described in the mouse, was found.

[Energy metabolism in cancer patients]

The presence of cachexia as defined by a series of clinical symptoms, such as anorexia, weight loss, muscular atrophy, tissue wasting, altered organ function, is frequently observed in cancer and makes a decisive contribution to morbidity and mortality. The onset of neoplastic cachexia is characterized by two events: the presence of primary or secondary anorexia and alterations of the host's intermediate metabolism. Among the most frequent metabolic alterations described in cancer patients is an absolute or relative increase in basal energy consumption with lack of adaptation to fasting. The causes of increased energy consumption in cancer patients are still not clear. Numerous studies on glucose, fat and protein metabolism induced by cancer have significantly contributed to our understanding of the phenomenon. The main alterations of the glucose metabolism are increased glucose turnover and reduced peripheral utilization, both of which probably depend on the presence of the tumour, as shown by their normalization after treatment. Increased gluconeogenesis, from lactate and from gluconeogenetic AA, is the main factor responsible for increased glucose turnover. The main alterations of the fat metabolism are increased mobilization of lipids from adipose tissues, reduced use of exogenous triglycerides and increased oxidation of free fatty acids that cannot be suppressed by glucose. The main alterations of protein metabolism are increased protein turnover with reduced synthesis and increased degradation of muscular proteins and increased hepatic protein synthesis. Knowledge of the pathogenesis of neoplastic cachexia represents a valuable aid for its effective prevention and treatment.

CTG repeat number in the nonaffected allele of myotonic dystrophy patients is not critical for disease expression

To investigate whether unusual allele segregation might explain the dominant negative effect of the expanded allele for myotonic dystrophy on myotonin protein kinase mRNA metabolism, which is suggested to cause the disease, we determined the number of CTG repeats at the DM locus in the nonaffected alleles of 64 DM (dystrophia myotonia) patients. The relative distribution was then compared with the distributions obtained from alleles of the normal parents and normal siblings of DM patients. Comparison was also made with the allele distribution of normal subjects from the same geographic area. It appears that the CTG repeat number of the nonaffected allele in DM patients is not critical for the expression of the disease.

Plasma tryptophan levels and anorexia in liver cirrhosis

OBJECTIVE

Increased brain tryptophan (TRP) availability for serotonin synthesis may play a role in the pathogenesis of anorexia. Since in chronic liver failure, increased plasma and cerebrospinal fluid TRP concentrations are characteristically reported, we hypothesize that also in liver cirrhosis increased brain TRP availability may constitute the pathogenic mechanism of anorexia. To test this hypothesis, the association between anorexia and plasma TRP was investigated.

METHODS

Anorexia and plasma amino acid concentrations were evaluated in 16 patients with liver cirrhosis and compared with those obtained in 13 healthy volunteers.

RESULTS

According to a questionnaire, 11 cirrhotic patients were considered as anorectic. In these patients, brain TRP availability was significantly higher than in nonanorectic patients and controls.

DISCUSSION

Increased brain TRP availability is also associated with anorexia in liver cirrhosis, and supports the hypothesis that increased serotonergic activity may constitute the common pathogenic mechanism for anorexia associated with different diseases.

Plasma tryptophan levels and anorexia in liver cirrhosis

OBJECTIVE

Increased brain tryptophan (TRP) availability for serotonin synthesis may play a role in the pathogenesis of anorexia. Since in chronic liver failure, increased plasma and cerebrospinal fluid TRP concentrations are characteristically reported, we hypothesize that also in liver cirrhosis increased brain TRP availability may constitute the pathogenic mechanism of anorexia. To test this hypothesis, the association between anorexia and plasma TRP was investigated.

METHODS

Anorexia and plasma amino acid concentrations were evaluated in 16 patients with liver cirrhosis and compared with those obtained in 13 healthy volunteers.

RESULTS

According to a questionnaire, 11 cirrhotic patients were considered as anorectic. In these patients, brain TRP availability was significantly higher than in nonanorectic patients and controls.

DISCUSSION

Increased brain TRP availability is also associated with anorexia in liver cirrhosis, and supports the hypothesis that increased serotonergic activity may constitute the common pathogenic mechanism for anorexia associated with different diseases.

Myotonic dystrophy: antisense oligonucleotide inhibition of DMPK gene expression in vitro

Antisense phosphorothioate oligonucleotides, targeted against the first codon starting region of DMPK mRNA, were successfully used in K562 and HepG2 cells to decrease DMPK expression. The most effective antisense oligo, MIO1, when added to K562 cells, shows a 75% reduction of the DMPK gene expression 6 hours after addition. The same molecule, when encapsulated in liposomes, delays myotonin mRNA decrease at 24 hours after cell treatment. This considerable success with such inhibition in vitro could be utilised to generate a cell model to study myotonic dystrophy (DM) chemio-physiological alterations.

Cancer anorexia: new pathogenic and therapeutic insights

During tumor growth, anorexia and reduced food intake markedly contribute to the development of malnutrition, thus worsening overall patients' survival. A better understanding of the pathophysiology of eating behavior may lead to new and more effective therapies, aiming at counteracting the detrimental effects of anorexia and reduced food intake on nutritional status and survival in cancer patients. Brain tryptophan and serotonin concentrations seem to play a pivotal role in the regulation of eating behavior. Increased brain serotonin activity is indeed associated with a reduction of food intake. It has been recently hypothesized that increased availability of tryptophan to the brain and the consequent increased serotonin activity may represent the pathogenic mechanism for cancer-associated anorexia. According to this hypothesis, the modulation of brain serotonin activity may result in an improvement of anorexia. Reducing brain tryptophan availability represents a possible mechanism to restore brain serotonin activity to normal. There is evidence that the oral administration of neutral amino acids competing with tryptophan for brain entry results in a significant improvement of cancer anorexia. The same treatment may also be effective in improving secondary anorexia, which is associated with other chronic illnesses, including renal and liver failure, sepsis, and so forth, sharing a similar pathogenic mechanism.

Tumor-induced changes in host metabolism: a possible marker of neoplastic disease

A large number of "biologic markers" for cancer have been described, including tumor-associated antigens, ectopic hormones, enzymes, and effects of tumor on the host's metabolism. Although tumors may metabolically differ from each other, they may induce similar derangements in glucose, lipid, and protein metabolism in the host. In particular, changes in carbohydrate metabolism may induce glucose intolerance that may be early and easily detected using an oral glucose tolerance test. Hypertriglyceridemia and reduced exogenous lipid clearance may represent an early marker of deranged lipid metabolism. Changes in protein metabolism, as reflected by plasma amino acid profile, may also represent a new diagnostic tool for cancer. Among other amino acids, free tryptophan seems to be the best candidate as a new useful marker for monitoring neoplastic disease. It is conceivable that, based on the understanding of the differences in plasma amino acid profiles, more specific and rational antineoplastic strategies may arise.

Plasma amino acid imbalance in patients with lung and breast cancer

In order to evaluate whether different solid tumors may specifically influence plasma free amino acid (PFAA) profile, PFAA were analysed in seventy-four patients with lung (41 patients) and breast cancer (33 patients) and 28 healthy subjects. In lung cancer patients a significant reduction of gluconeogenic amino acids, threonine, serine, glycine and a significant increase of free tryptophan and glutamic acid was found. In breast cancer patients a significant increase of ornithine, glutamic acid and free tryptophan was found. The comparison of PFAA profiles between lung and breast cancer suggests that different tumors have a different influence on the host's PFAA pattern.

Bacteriophage T4 gene 28

The complete nucleotide sequence of bacteriophage T4D gene 28 has been determined. Gene 28 product is a structural component of the viral baseplate for which an enzymatic activity has also been proposed.

Cytokines, tryptophan and anorexia in cancer patients before and after surgical tumor ablation

Serotoninergic system activity and cytokine production have been both implicated in the pathogenesis of cancer anorexia. To verify the existence of relationships between tryptophan, cytokines and anorexia, twenty cancer and six non-neoplastic patients were studied. Plasma amino acid concentration, including tryptophan, and spontaneous and LPS stimulated tumor necrosis factor and interleukin-1 release from peripheral blood mononuclear cells were determined before and after surgery in both groups of patients. A close relationship between plasma free tryptophan concentration and anorexia was observed, whereas no relationship between cytokine production and either anorexia or plasma tryptophan was found in cancer patients.