Vascular integrins in tumor angiogenesis: mediators and therapeutic targets.

The notion that tumor angiogenesis may have therapeutic implications in the control of tumor growth was introduced by Dr. Judah Folkman in 1971. The approval of Avastin in 2004 as the first antiangiogenic systemic drug to treat cancer patients came as a validation of this visionary concept and opened new perspectives to the treatment of cancer. In addition, this success boosted the field to the quest for new therapeutic targets and antiangiogenic drugs. Preclinical and clinical evidence indicate that vascular integrins may be valid therapeutic targets. In preclinical studies, pharmacological inhibition of integrin function efficiently suppressed angiogenesis and inhibited tumor progression. alphaVbeta3 and alphaVbeta5 were the first vascular integrins targeted to suppress tumor angiogenesis. Subsequent experiments revealed that at least four additional integrins (i.e., alpha1beta1, alpha2beta1, alpha5beta1, and alpha6beta4) might be potential therapeutic targets. In clinical studies low-molecular-weight integrin inhibitors and anti-integrin function-blocking antibodies demonstrated low toxicity and good tolerability and are now being tested in combination with radiotherapy and chemotherapy for anticancer activity in patients. In this article the authors review the role of integrins in angiogenesis, present recent development in the use of alphaVbeta3 and alpha5beta1 integrin antagonists as potential therapeutics in cancer, and discuss future perspectives.

Strategies for preventing late-onset cytomegalovirus disease in organ transplant recipients.

Objective: The incidence of late-onset cytomegalovirus disease (i.e. disease appearing after discontinuation of antiviral prophylaxis) in solid-organ transplant recipients remains excessively high. This review will focus on describing the several strategies that could potentially reduce the incidence of late-onset cytomegalovirus disease. Methods: We reviewed the literature and presented our own clinical experience in the field. Results: The incidence of late-onset cytomegalovirus disease in recent trials can be as high as 36% in high-risk patients (donor positive/recipient negative for cytomegalovirus). The extension of antiviral prophylaxis to six months has recently proven in a prospective randomized controlled trial to be effective for reducing late-onset cytomegalovirus disease. The monitoring of cytomegalovirus viral load by PCR after the discontinuation of prophylaxis seems to be of moderate usefulness in low/intermediate-risk patients. The use of low-dose valganciclovir could reduce drug toxicity and costs while maintaining similar efficacy, but further studies are needed. A potentially interesting approach to predict the individual risk for development of cytomegalovirus disease appears to be the assessment of specific cell-mediated immune response. If cell-mediated immunity assays become widely available in transplant centers in the future, these assays may possibly be used to tailor the cytomegalovirus preventive strategy on an individual basis. Finally, recent prospective trials have evaluated novel cytomegalovirus vaccines that merit further evaluation in the transplant setting, although currently there is no cytomegalovirus vaccine that has been approved for routine clinical use. Conclusions: Several studies have recently evaluated novel strategies to reduce the incidence of late-onset cytomegalovirus disease. It is therefore expected that this improvement in preventive strategies will allow to further reduce the negative effects of cytomegalovirus disease after transplantation.

Chemoradiotherapy in malignant glioma: standard of care and future directions.

Glioma has been considered resistant to chemotherapy and radiation. Recently, concomitant and adjuvant chemoradiotherapy with temozolomide has become the standard treatment for newly diagnosed glioblastoma. Conversely (neo-)adjuvant PCV (procarbazine, lomustine, vincristine) failed to improve survival in the more chemoresponsive tumor entities of anaplastic oligoastrocytoma and oligodendroglioma. Preclinical investigations suggest synergism or additivity of radiotherapy and temozolomide in glioma cell lines. Although the relative contribution of the concomitant and the adjuvant chemotherapy, respectively, cannot be assessed, the early introduction of chemotherapy and the simultaneous administration with radiotherapy appear to be key for the improvement of outcome. Epigenetic inactivation of the DNA repair enzyme methylguanine methyltransferase (MGMT) seems to be the strongest predictive marker for outcome in patients treated with alkylating agent chemotherapy. Patients whose tumors do not have MGMT promoter methylation are less likely to benefit from the addition of temozolomide chemotherapy and require alternative treatment strategies. The predictive value of MGMT gene promoter methylation is being validated in ongoing trials aiming at overcoming this resistance by a dose-dense continuous temozolomide administration or in combination with MGMT inhibitors. Understanding of molecular mechanisms allows for rational targeting of specific pathways of repair, signaling, and angiogenesis. The addition of tyrosine kinase inhibitors vatalanib (PTK787) and vandetinib (ZD6474), the integrin inhibitor cilengitide, the monoclonal antibodies bevacizumab and cetuximab, the mammalian target of rapamycin inhibitors temsirolimus and everolimus, and the protein kinase C inhibitor enzastaurin, among other agents, are in clinical investigation, building on the established chemoradiotherapy regimen for newly diagnosed glioblastoma.

Recombinant human tumor necrosis factor: an efficient agent for cancer treatment.

Recombinant human TNF (rhTNF) has a selective effect on endothelial cells in tumour angiogenic vessels. Its clinical use has been limited because of its property to induce vascular collapsus. TNF administration through isolated limb perfusion (ILP) for regionally advanced melanomas and soft tissue sarcomas of the limbs was shown to be safe and efficient. When combined to the alkylating agent melphalan, a single ILP produces a very high objective response rate. ILP with TNF and melphalan provided the proof of concept that a vasculotoxic strategy combined to chemotherapy may produce a strong anti-tumour effect. The registered indication of TNF-based ILP is a regional therapy for regionally spread tumours. In soft tissue sarcomas, it is a limb sparing neoadjuvant treatment and, in melanoma in-transit metastases, a curative treatment. Despite its demonstrated regional efficiency TNF-based ILP is unlikely to have any impact on survival. High TNF dosages induce endothelial cells apoptosis, leading to vascular destruction. However, lower TNF dosage produces a very strong effect that is to increase the drug penetration into the tumour, presumably by decreasing the intratumoural hypertension resulting in better tumour uptake. TNF-ILP allowed the identification of the role of alphaVbeta3 integrin deactivation as an important mechanism of antiangiogenesis. Several recent studies have shown that TNF targeting is possible, paving the way to a new opportunity to administer TNF systemically for improving cancer drug penetration. TNF was the first agent registered for the treatment of cancer that improves drug penetration in tumours and selectively destroys angiogenic vessels.

Recent advances in the epidermal growth factor receptor/ligand system biology on skin homeostasis and keratinocyte stem cell regulation.

The epidermal growth factor (EGF) receptor/ligand system stimulates multiple pathways of signal transduction, and is activated by various extracellular stimuli and inter-receptor crosstalk signaling. Aberrant activation of EGF receptor (EGFR) signaling is found in many tumor cells, and humanized neutralizing antibodies and synthetic small compounds against EGFR are in clinical use today. However, these drugs are known to cause a variety of skin toxicities such as inflammatory rash, skin dryness, and hair abnormalities. These side effects demonstrate the multiple EGFR-dependent homeostatic functions in human skin. The epidermis and hair follicles are self-renewing tissues, and keratinocyte stem cells are crucial for maintaining these homeostasis. A variety of molecules associated with the EGF receptor/ligand system are involved in epidermal homeostasis and hair follicle development, and the modulation of EGFR signaling impacts the behavior of keratinocyte stem cells. Understanding the roles of the EGF receptor/ligand system in skin homeostasis is an emerging issue in dermatology to improve the current therapy for skin disorders, and the EGFR inhibitor-associated skin toxicities. Besides, controlling of keratinocyte stem cells by modulating the EGF receptor/ligand system assures advances in regenerative medicine of the skin. We present an overview of the recent progress in the field of the EGF receptor/ligand system on skin homeostasis and regulation of keratinocyte stem cells.

Myocardial MIBG scintigraphy: a useful clinical tool? : A retrospective study in 50 parkinsonian patients.

Meta-iodbenzylguanidine scintigraphy (MIBG scintigraphy) shows reduced uptake in idiopathic Parkinson's disease (IPD), idiopathic REM sleep behavior disorder (IRBD) and Lewy body dementia (LBD), but not in other parkinsonian or dementia syndromes. We retrospectively reevaluated 50 patients. Concordance rate between last clinical diagnosis and scintigraphy diagnosis was only given in two-thirds of the patients. Confounding factors were: decreasing heart/mediastinum ratio (HMR) with progressive age, higher HMR in women and possibly interference with antihypertensive medication. Standardization of the methods and precise clinical guidelines are warranted for better clinical use.

Diagnosis of tuberculosis infection using interferon-γ-based assays

Interferon-γ-based assays, collectively known as IFN-γ release assays (IGRAs), have emerged as a reliable alternative to the old tuberculin skin test (TST) for the immunodiagnosis of tuberculosis (TB) infection. The 2 commercially available tests, the enzyme-linked immunosorbent assay (ELISA), QuantiFERON-TB Gold Intube (QFT-IT), and the enzyme-linked immunospot assay (ELISPOT), T-SPOT.TB, are more accurate than TST for the diagnosis of TB, since they are highly specific and correlate better with the existence of risk factors for the infection. According to the available data, T-SPOT.TB obtains a higher number of positive results than QFT-IT, while its specificity seems to be lower. Although the sensitivity of the IFN-γ -based assays may be impaired to some extent by cellular immunosuppression and extreme ages of life, they perform better than TST in these situations. Data from longitudinal studies suggest that IFN-γ-based tests are better predictors of subsequent development of active TB than TST; however this prognostic value has not been consistently demonstrated. This review focuses on the clinical use of the IFN-γ -based tests in different risk TB groups, and notes the main limitations and areas for future development.

The quest for surrogate markers of angiogenesis: a paradigm for translational research in tumor angiogenesis and anti-angiogenesis trials.

Inhibition of tumor angiogenesis suppresses tumor growth and metastatic spreading in many experimental models, suggesting that anti-angiogenic drugs may be used to treat human cancer. During the past decade more than eighty molecules that showed anti-angiogenic activity in preclinical studies were tested in clinical cancer trials, but most of them failed to demonstrate any measurable anti-tumor activity and none have been approved for clinical use. Recent results stemming from trials with anti-VEGF antibodies, used alone or in combination with chemotherapy, suggest that systemic anti-angiogenic therapy may indeed have a measurable impact on cancer progression and patient survival. From the clinical studies it became nevertheless clear that the classical endpoints used in anti-cancer trials do not bring sufficient discriminative power to monitor the effects of anti-angiogenic drugs. It is therefore necessary to identify and validate molecular, cellular and functional surrogate markers of angiogenesis to monitor activity and efficacy of anti-angiogenic drugs in patients. Availability of such markers will be instrumental to re-evaluate the role of tumor angiogenesis in human cancer, to identify new molecular targets and drugs, and to improve planning, monitoring and interpretation of future studies. Future anti-angiogenesis trials integrating biological endpoints and surrogate markers or angiogenesis will require close collaboration between clinical investigators and laboratory-based researchers.

Inhibition of tumor angiogenesis by non-steroidal anti-inflammatory drugs: emerging mechanisms and therapeutic perspectives.

Chronic intake of non steroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of developing gastrointestinal tumors, in particular colon cancer. Increasing evidence indicates that NSAID exert tumor-suppressive activity on pre-malignant lesions (polyps) in humans and on established experimental tumors in mice. Some of the tumor-suppressive effects of NSAIDs depend on the inhibition of cyclooxygenase-2 (COX-2), a key enzyme in the synthesis of prostaglandins and thromboxane, which is highly expressed in inflammation and cancer. Recent findings indicate that NSAIDs exert their anti-tumor effects by suppressing tumor angiogenesis. The availability of COX-2-specific NSAIDs opens the possibility of using this drug class as anti-angiogenic agents in combination with chemotheapy or radiotherapy for the treatment of human cancer. Here we will briefly review recent advances in the understanding of the mechanism by which NSAIDs suppress tumor angiogenesis and discuss their potential clinical application as anti-cancer agents.

Stratégies thérapeutiques pour le traitement des gliomes [Therapeutic strategies for the management of gliomas]

The management of gliomas remains challenging and requires a multidisciplinary approach that involves neurosurgeons, radiation therapists and oncologists. For patients with glioblastomas, progress has been made in recent years with the introduction of a combined modality treatment associating radiation therapy and concomitant chemotherapy with the novel alkylating agent temozolomide. This combination resulted in a significant prolongation of survival and increase in the number of patients with survival well beyond two years. Since then, interest in developing new agents in this disease has dramatically increased. In parallel, molecular markers, such as methylation status of MGMT or identification of the translocation of 1p and 19q in oligodendrogliomas have allowed to identify distinct subtypes with exquisite response to treatment or different prognosis. These developments have implications for the development of clinical trials of new potential drug treatments. In this article, we provide a review of the current management of low- and high-grade gliomas, including astrocytomas, oligodendrogliomas and glioblastomas and provide an outlook into future potential therapies.

The need for combination antihypertensive therapy to reach target blood pressures: what has been learned from clinical practice and morbidity-mortality trials?

Pharmacological treatment of hypertension represents a cost-effective way for preventing cardiovascular and renal complications. To benefit maximally from antihypertensive treatment blood pressure (BP) should be brought to below 140/90 mmHg in every hypertensive patient, and even lower (< 130/80 mmHg) if diabetes or renal disease co-exists. Most of the time such targets cannot be reached using monotherapies. This is especially true in patients who exhibit a high cardiovascular risk. The co-administration of two agents acting by different mechanisms considerably increases BP control. Such preparations are not only efficacious, but also well tolerated, and some fixed low-dose combinations have a tolerability profile similar to placebo. This is for instance the case for the preparation containing the angiotensin-converting enzyme inhibitor perindopril (2 mg) and the diuretic indapamide (0.625 mg), a fixed low-dose combination that has recently been shown in controlled interventional trials to be more effective than monotherapies in reducing albuminuria, regressing cardiac hypertrophy and improving macrovascular stiffness. Fixed-dose combinations are becoming more and more popular and are even proposed by current hypertension guidelines as a first-line option to treat hypertensive patients.

Role of trabectedin in the treatment of soft tissue sarcoma.

Interest in marine natural products has allowed the discovery of new drugs and trabectedin (ET-743, Yondelis), derived from the marine tunicate Ecteinascidia turbinata, was approved for clinical use in 2007. It binds to the DNA minor groove leading to interferences with the intracellular transcription pathways and DNA-repair proteins. In vitro antitumor activity was demonstrated against various cancer cell lines and soft tissue sarcoma cell lines. In phase I studies tumor responses were observed also in osteosarcomas and different soft tissue sarcoma subtypes. The most common toxicities were myelosuppression and transient elevation of liver function tests, which could be reduced by dexamethasone premedication. The efficacy of trabectedin was established in three phase II studies where it was administered at 1.5 mg/m2 as a 24 h intravenous infusion repeated every three weeks, in previously treated patients. The objective response rate was 3.7%-8.3% and the tumor control rate (which included complete response, partial response and stable disease) was obtained in half of patients for a median overall survival reaching 12 months. In nonpretreated patients the overall response rate was 17%. Twenty-four percent of patients were without progression at six months. The median overall survival was almost 16 months with 72% surviving at one year. Predictive factors of response are being explored to identify patients who are most likely to respond to trabectedin. Combination with other agents are currently studied with promising results. In summary trabectedin is an active new chemotherapeutic agents that has demonstrated its role in the armamentarium of treatments for patients with sarcomas.

Genetic association analyses reveal a role for vitamin D insufficiency in hepatitis C virus-associated hepatocellular carcinoma development

Background: V itamin D insufficiency has been associated with the occurrence of various types of cancer, but causal relationships remain elusive. Methods: Associations between t he r isk o f HCV-related HCC development and CYP2R1 , GC, and DHCR7 genotypes, which are genetic determinants of reduced 25-OH-vitamin D3 (25[OH]D3) serum levels, were determined. Results: A t otal of 5604 HCV-infected patients, 1279 with a nd 4325 without progression to HCC, w ere identified. The well-known association between 25(OH)D3 s erum levels and variations in CYP2R1 ( rs1993116, rs10741657), GC ( rs2282679), a nd DHCR7 ( rs7944926, rs12785878) g enotypes was also apparent in patients w ith chronic hepatitis C. The same genotypes of t hese single nucleotide polymorphisms (SNPs), w hich are associated with reduced 25(OH)D3 s erum levels, were significantly associated with HCV-associated HCC (P=0.07 [OR=1.13] for CYP2R1 , P=0.007 [OR=1.56] for GC, P=0.003 [OR=1.42] for DHCR7; ORs for risk genotypes). In contrast, no association between t hese genetic variations and the o utcome of antiviral therapy with pegylated interferon-α and ribavirin ( P>0.2 for e ach SNP) or liver fibrosis progression rate (P>0.2 for each SNP) was observed, s uggesting a specific influence o f the genetic d eterminants of 25(OH)D3 s erum levels o n hepatocarcinogenesis. Conclusions: Our data suggest a relatively weak but functionally relevant role for vitamin D in the prevention of HCV-related HCC development. Controlled clinical trials to assess the benefit of vitamin D supplementation in HCVinfected patients with advanced liver fibrosis or cirrhosis are warranted.

Neuropeptide Y and corticotropin-releasing hormone in CSF mark response to antidepressive treatment with citalopram.

Neuropeptides appear to play a role in the pathophysiology of depression and electroconvulsive treatment and lithium affect these compounds in human cerebrospinal fluid (CSF) and rodent brain. Consequently, we investigated whether long-term treatment with the selective serotonin reuptake inhibitor (SSRI) citalopram (Cit) would also affect neuropeptides in CSF of depressed patients. Changes in CSF monoamine metabolites were also explored. CSF concentrations of corticotropin-releasing hormone (CRH)-like immunoreactivity (-LI), neuropeptide Y (NPY)-LI, and Cit were determined in 21 patients with major depression. Lumbar puncture was performed in the morning at baseline and was repeated after at least 4 wk of Cit treatment (40 mg/d). The severity of depression was assessed by the Hamilton Rating Scale for Depression (HAMD). Cit treatment was associated with a significant increase in NPY-LI and decrease in CRH-LI. An evaluation of the relationship between changes in concentrations of NPY-LI, CRH-LI, and the clinical response showed significant correlations between these parameters. Significant NPY and CRH changes in CSF following treatment as well as correlations to changes in HAMD support the hypothesis that these two peptides play a role in affective disorders and are markers of therapeutic response.

Emerging paradigms and questions on pro-angiogenic bone marrow-derived myelomonocytic cells.

Cancer-related inflammation has emerged in recent years as a major event contributing to tumor angiogenesis, tumor progression and metastasis formation. Bone marrow-derived and inflammatory cells promote tumor angiogenesis by providing endothelial progenitor cells that differentiate into mature endothelial cells, and by secreting pro-angiogenic factors and remodeling the extracellular matrix to stimulate angiogenesis though paracrine mechanisms. Several bone marrow-derived myelonomocytic cells, including monocytes and macrophages, have been identified and characterized by several laboratories in recent years. While the central role of these cells in promoting tumor angiogenesis, tumor progression and metastasis is nowadays well established, many questions remain open and new ones are emerging. These include the relationship between their phenotype and function, the mechanisms of pro-angiogenic programming, their contribution to resistance to anti-angiogenic treatments and to metastasis and their potential clinical use as biomarkers of angiogenesis and anti-angiogenic therapies. Here, we will review phenotypical and functional aspects of bone marrow-derived myelonomocytic cells and discuss some of the current outstanding questions.