Presence of Epstein-Barr virus latency type III at the single cell level in post- transplantation lymphoproliferative disorders and AIDS related lymphomas

AIMS: To investigate the expression pattern of Epstein-Barr virus (EBV) latent genes at the single cell level in post-transplantation lymphoproliferative disorders and acquired immunodefiency syndrome (AIDS) related lymphomas, in relation to cellular morphology. METHODS: Nine post-transplantation lymphoproliferative disorders and three AIDS related lymphomas were subjected to immunohistochemistry using monoclonal antibodies specific for EBV nuclear antigen 1 (EBNA1) (2H4), EBNA2 (PE2 and the new rat anti-EBNA2 monoclonal antibodies 1E6, R3, and 3E9), and LMP1 (CS1-4 and S12). Double staining was performed combining R3 or 3E9 with S12. RESULTS: R3 and 3E9 anti-EBNA2 monoclonal antibodies were more sensitive than PE2, enabling the detection of more EBNA2 positive lymphoma cells. Both in post-transplantation lymphoproliferative disorders and AIDS related lymphomas, different expression patterns were detected at the single cell level. Smaller neoplastic cells were positive for EBNA2 but negative for LMP1. Larger and more blastic neoplastic cells, sometimes resembling Reed-Sternberg cells, were LMP1 positive but EBNA2 negative (EBV latency type II). Morphologically intermediate neoplastic cells coexpressing EBNA2 and LMP1 (EBV latency type III), were detected using R3 and 3E9, and formed a considerable part of the neoplastic population in four of nine post-transplantation lymphoproliferative disorders and two of three AIDS related lymphomas. All samples contained a subpopulation of small tumour cells positive exclusively for Epstein-Barr early RNA and EBNA1. The relation between cellular morphology and EBV expression patterns in this study was less pronounced in AIDS related lymphomas than in post-transplantation lymphoproliferative disorders, because the AIDS related lymphomas were less polymorphic than the post-transplantation lymphoproliferative disorders. CONCLUSIONS: In post-transplantation lymphoproliferative disorders and AIDS related lymphomas, EBV latency type III can be detected by immunohistochemistry in a subpopulation of tumour cells using sensitive monoclonal antibodies R3 and 3E9. Our data suggest that EBV infected tumour cells in these lymphomas undergo gradual changes in the expression of EBV latent genes, and that these changes are associated with changes in cellular morphology

Improved blood tests for cancer screening: general or specific?

Diagnosis of cancer at an early stage leads to improved survival. However, most current blood tests detect single biomarkers that are of limited suitability for screening, and existing screening programmes look only for cancers of one particular type. A new approach is needed. Recent developments suggest the possibility of blood-based screening for multiple tumour types. It may be feasible to develop a high-sensitivity general screen for cancer using multiple proteins and nucleic acids present in the blood of cancer patients, based on the biological characteristics of cancer. Positive samples in the general screen would be submitted automatically for secondary screening using tests to help define the likelihood of cancer and provide some indication of its type. Only those at high risk would be referred for further clinical assessment to permit early treatment and mitigate potential overdiagnosis. While the assays required for each step exist, they have not been used in this way. Recent experience of screening for breast, cervical and ovarian cancers suggest that there is likely to be widespread acceptance of such a strategy

An Assessment of the Effectiveness of High Definition Cameras as Remote Monitoring Tools for Dolphin Ecology Studies.

Research involving marine mammals often requires costly field programs. This paper assessed whether the benefits of using cameras outweighs the implications of having personnel performing marine mammal detection in the field. The efficacy of video and still cameras to detect Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the Fremantle Harbour (Western Australia) was evaluated, with consideration on how environmental conditions affect detectability. The cameras were set on a tower in the Fremantle Port channel and videos were perused at 1.75 times the normal speed. Images from the cameras were used to estimate position of dolphins at the water’s surface. Dolphin detections ranged from 5.6 m to 463.3 m for the video camera, and from 10.8 m to 347.8 m for the still camera. Detection range showed to be satisfactory when compared to distances at which dolphins would be detected by field observers. The relative effect of environmental conditions on detectability was considered by fitting a Generalised Estimation Equations (GEEs) model with Beaufort, level of glare and their interactions as predictors and a temporal auto-correlation structure. The best fit model indicated level of glare had an effect, with more intense periods of glare corresponding to lower occurrences of observed dolphins. However this effect was not large (-0.264) and the parameter estimate was associated with a large standard error (0.113).The limited field of view was the main restraint in that cameras can be only applied to detections of animals observed rather than counts of individuals. However, the use of cameras was effective for long term monitoring of occurrence of dolphins, outweighing the costs and reducing the health and safety risks to field personal. This study showed that cameras could be effectively implemented onshore for research such as studying changes in habitat use in response to development and construction activities

Possible involvement of integrin-mediated signalling in oocyte activation: evidence that a cyclic RGD-containing peptide can stimulate protein kinase C and cortical granule exocytosis in mouse oocytes

BACKGROUND: Mammalian sperm-oocyte interaction at fertilization involves several combined interactions between integrins on the oocyte and integrin ligands (disintegrins) on the sperm. Recent research has indicated the ability of peptides containing the RGD sequence that characterized several sperm disintegrins, to induce intracellular Ca2+ transients and to initiate parthenogenetic development in amphibian and bovine oocytes. In the present study, we investigate the hypothesis that an integrin-associated signalling may participate in oocyte activation signalling by determining the ability of a cyclic RGD-containing peptide to stimulate the activation of protein kinase C (PKC) and the exocytosis of cortical granules in mouse oocytes. METHODS: An In-Vitro-Fertilization assay (IVF) was carried in order to test the condition under which a peptide containing the RGD sequence, cyclo(Arg-Gly-Asp-D-Phe-Val), was able to inhibit sperm fusion with zona-free mouse oocytes at metaphase II stage. PKC activity was determined by means of an assay based on the ability of cell lysates to phosphorylate MARKS peptide, a specific PKC substrate. Loss of cortical granules was evaluated by measuring density in the oocyte cortex of cortical granules stained with LCA-biotin/Texas red-streptavidin. In all the experiments, effects of a control peptide containing a non RGD sequence, cyclo(Arg-Ala-Asp-D-Phe-Val), were evaluated. RESULTS: The IVF assay revealed that the fusion rate declined significantly when insemination was carried out in the presence of cyclic RGD peptide at concentrations > or = 250 microM (P < 0.05, Student-Newman-Keuls Method). When the peptide was applied to the oocytes at these concentrations, a dose-dependent increase of PKC activity was observed, in association with a loss of cortical granules ranging from 38+/-2.5 % to 52+/-5.4 %. Evaluation of meiotic status revealed that cyclic RGD peptide was ineffective in inducing meiosis resumption under conditions used in the present study. CONCLUSION: The presents results provide evidence that a cyclic RGD peptide highly effective in inhibiting sperm-oocyte interaction stimulates in mouse oocytes the activation of PKC and the exocytosis of cortical granules. These data support the view that RGD-binding receptors may function as signalling receptors giving rise integrated signalling not sufficient for a full oocyte activation response. This study may contribute to the understanding of possible negative effects of skipping gamete interaction in IVF techniques

A selective eradication of human nonhereditary breast cancer cells by phenanthridine-derived polyADP-ribose polymerase inhibitors

INTRODUCTION: PARP-1 (polyADP-ribose polymerase-1) is known to be activated in response to DNA damage, and activated PARP-1 promotes DNA repair. However, a recently disclosed alternative mechanism of PARP-1 activation by phosphorylated externally regulated kinase (ERK) implicates PARP-1 in a vast number of signal-transduction networks in the cell. Here, PARP-1 activation was examined for its possible effects on cell proliferation in both normal and malignant cells. METHODS: In vitro (cell cultures) and in vivo (xenotransplants) experiments were performed. RESULTS: Phenanthridine-derived PARP inhibitors interfered with cell proliferation by causing G2/M arrest in both normal (human epithelial cells MCF10A and mouse embryonic fibroblasts) and human breast cancer cells MCF-7 and MDA231. However, whereas the normal cells were only transiently arrested, G2/M arrest in the malignant breast cancer cells was permanent and was accompanied by a massive cell death. In accordance, treatment with a phenanthridine-derived PARP inhibitor prevented the development of MCF-7 and MDA231 xenotransplants in female nude mice. Quiescent cells (neurons and cardiomyocytes) are not impaired by these PARP inhibitors. CONCLUSIONS: These results outline a new therapeutic approach for a selective eradication of abundant nonhereditary human breast cancers

Growth regulation of simian and human AIDS-related non-Hodgkin's lymphoma cell lines by TGF-β1 and IL-6

BACKGROUND: AIDS-related non-Hodgkin's lymphoma (AIDS-NHL) is the second most frequent cancer associated with AIDS, and is a frequent cause of death in HIV-infected individuals. Experimental analysis of AIDS-NHL has been facilitated by the availability of an excellent animal model, i.e., simian Acquired Immunodeficiency Syndrome (SAIDS) in the rhesus macaque consequent to infection with simian immunodeficiency virus. A recent study of SAIDS-NHL demonstrated a lymphoma-derived cell line to be sensitive to the growth inhibitory effects of the ubiquitous cytokine, transforming growth factor-beta (TGF-beta). The authors concluded that TGF-beta acts as a negative growth regulator of the lymphoma-derived cell line and, potentially, as an inhibitory factor in the regulatory network of AIDS-related lymphomagenesis. The present study was conducted to assess whether other SAIDS-NHL and AIDS-NHL cell lines are similarly sensitive to the growth inhibitory effects of TGF-beta, and to test the hypothesis that interleukin-6 (IL-6) may represent a counteracting positive influence in their growth regulation. METHODS: Growth stimulation or inhibition in response to cytokine treatment was quantified using trypan blue exclusion or colorimetric MTT assay. Intracellular flow cytometry was used to analyze the activation of signaling pathways and to examine the expression of anti-apoptotic proteins and distinguishing hallmarks of AIDS-NHL subclass. Apoptosis was quantified by flow cytometric analysis of cell populations with sub-G1 DNA content and by measuring activated caspase-3. RESULTS: Results confirmed the sensitivity of LCL8664, an immunoblastic SAIDS-NHL cell line, to TGF-beta1-mediated growth inhibition, and further demonstrated the partial rescue by simultaneous treatment with IL-6. IL-6 was shown to activate STAT3, even in the presence of TGF-beta1, and thereby to activate proliferative and anti-apoptotic pathways. By comparison, human AIDS-NHL cell lines differed in their responsiveness to TGF-beta1 and IL-6. Analysis of a recently derived AIDS-NHL cell line, UMCL01-101, indicated that it represents immunoblastic AIDS-DLCBL. Like LCL-8664, UMCL01-101 was sensitive to TGF-beta1-mediated inhibition, rescued partially by IL-6, and demonstrated rapid STAT3 activation following IL-6 treatment even in the presence of TGF-beta1. CONCLUSION: These studies indicate that the sensitivity of immunoblastic AIDS- or SAIDS-DLBCL to TGF-beta1-mediated growth inhibition may be overcome through the stimulation of proliferative and anti-apoptotic signals by IL-6, particularly through the rapid activation of STAT3

A Novel Classification of Lung Cancer into Molecular Subtypes

The remarkably heterogeneous nature of lung cancer has become more apparent over the last decade. In general, advanced lung cancer is an aggressive malignancy with a poor prognosis. The discovery of multiple molecular mechanisms underlying the development, progression, and prognosis of lung cancer, however, has created new opportunities for targeted therapy and improved outcome. In this paper, we define “molecular subtypes” of lung cancer based on specific actionable genetic aberrations. Each subtype is associated with molecular tests that define the subtype and drugs that may potentially treat it. We hope this paper will be a useful guide to clinicians and researchers alike by assisting in therapy decision making and acting as a platform for further study. In this new era of cancer treatment, the ‘one-size-fits-all’ paradigm is being forcibly pushed aside—allowing for more effective, personalized oncologic care to emerge

Assessing Predation Risk to Threatened Fauna from their Prevalence in Predator Scats: Dingoes and Rodents in Arid Australia

The prevalence of threatened species in predator scats has often been used to gauge the risks that predators pose to threatened species, with the infrequent occurrence of a given species often considered indicative of negligible predation risks. In this study, data from 4087 dingo (Canis lupus dingo and hybrids) scats were assessed alongside additional information on predator and prey distribution, dingo control effort and predation rates to evaluate whether or not the observed frequency of threatened species in dingo scats warrants more detailed investigation of dingo predation risks to them. Three small rodents (dusky hopping-mice Notomys fuscus; fawn hopping-mice Notomys cervinus; plains mice Pseudomys australis) were the only threatened species detected in <8% of dingo scats from any given site, suggesting that dingoes might not threaten them. However, consideration of dingo control effort revealed that plains mice distribution has largely retracted to the area where dingoes have been most heavily subjected to lethal control. Assessing the hypothetical predation rates of dingoes on dusky hopping-mice revealed that dingo predation alone has the potential to depopulate local hopping-mice populations within a few months. It was concluded that the occurrence of a given prey species in predator scats may be indicative of what the predator ate under the prevailing conditions, but in isolation, such data can have a poor ability to inform predation risk assessments. Some populations of threatened fauna assumed to derive a benefit from the presence of dingoes may instead be susceptible to dingo-induced declines under certain conditions