GLUT3 is induced during epithelial-mesenchymal transition and promotes tumor cell proliferation in non-small cell lung cancer.

BACKGROUND: Alterations in glucose metabolism and epithelial-mesenchymal transition (EMT) constitute two important characteristics of carcinoma progression toward invasive cancer. Despite an extensive characterization of each of them separately, the links between EMT and glucose metabolism of tumor cells remain elusive. Here we show that the neuronal glucose transporter GLUT3 contributes to glucose uptake and proliferation of lung tumor cells that have undergone an EMT. RESULTS: Using a panel of human non-small cell lung cancer (NSCLC) cell lines, we demonstrate that GLUT3 is strongly expressed in mesenchymal, but not epithelial cells, a finding corroborated in hepatoma cells. Furthermore, we identify that ZEB1 binds to the GLUT3 gene to activate transcription. Importantly, inhibiting GLUT3 expression reduces glucose import and the proliferation of mesenchymal lung tumor cells, whereas ectopic expression in epithelial cells sustains proliferation in low glucose. Using a large microarray data collection of human NSCLCs, we determine that GLUT3 expression correlates with EMT markers and is prognostic of poor overall survival. CONCLUSIONS: Altogether, our results reveal that GLUT3 is a transcriptional target of ZEB1 and that this glucose transporter plays an important role in lung cancer, when tumor cells loose their epithelial characteristics to become more invasive. Moreover, these findings emphasize the development of GLUT3 inhibitory drugs as a targeted therapy for the treatment of patients with poorly differentiated tumors.

Differential prefrontal-like deficit in children after cerebellar astrocytoma and medulloblastoma tumor

BACKGROUND This study was realized thanks to the collaboration of children and adolescents who had been resected from cerebellar tumors. The medulloblastoma group (CE+, n = 7) in addition to surgery received radiation and chemotherapy. The astrocytoma group (CE, n = 13) did not receive additional treatments. Each clinical group was compared in their executive functioning with a paired control group (n = 12). The performances of the clinical groups with respect to controls were compared considering the tumor's localization (vermis or hemisphere) and the affectation (or not) of the dentate nucleus. Executive variables were correlated with the age at surgery, the time between surgery-evaluation and the resected volume. METHODS The executive functioning was assessed by means of WCST, Complex Rey Figure, Controlled Oral Word Association Test (letter and animal categories), Digits span (WISC-R verbal scale) and Stroop test. These tests are very sensitive to dorsolateral PFC and/or to medial frontal cortex functions. The scores for the non-verbal Raven IQ were also obtained. Direct scores were corrected by age and transformed in standard scores using normative data. The neuropsychological evaluation was made at 3.25 (SD = 2.74) years from surgery in CE group and at 6.47 (SD = 2.77) in CE+ group. RESULTS The Medulloblastoma group showed severe executive deficit (tumor's localization and dentate affectation showed different profile and level of impairment: moderate to slight for vermal and hemispheric patients respectively. The resected volume, age at surgery and the time between surgery-evaluation correlated with some neuropsychological executive variables. CONCLUSION Results suggest a differential prefrontal-like deficit due to cerebellar lesions and/or cerebellar-frontal diaschisis, as indicate the results in astrocytoma group (without treatments), that also can be generated and/or increased by treatments in the medulloblastoma group. The need for differential rehabilitation strategies for specific clinical groups is remarked. The results are also discussed in the context of the Cerebellar Cognitive Affective Syndrome.

A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation

BACKGROUND Phytopharmacological studies of different Calendula extracts have shown anti-inflammatory, anti-viral and anti-genotoxic properties of therapeutic interest. In this study, we evaluated the in vitro cytotoxic anti-tumor and immunomodulatory activities and in vivo anti-tumor effect of Laser Activated Calendula Extract (LACE), a novel extract of the plant Calendula Officinalis (Asteraceae). METHODS An aqueous extract of Calendula Officinalis was obtained by a novel extraction method in order to measure its anti-tumor and immunomodulatory activities in vitro. Tumor cell lines derived from leukemias, melanomas, fibrosarcomas and cancers of breast, prostate, cervix, lung, pancreas and colorectal were used and tumor cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of LACE on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in LACE-treated cells. In vivo anti-tumor activity was evaluated in nude mice bearing subcutaneously human Ando-2 melanoma cells. RESULTS The LACE extract showed a potent in vitro inhibition of tumor cell proliferation when tested on a wide variety of human and murine tumor cell lines. The inhibition ranged from 70 to 100%. Mechanisms of inhibition were identified as cell cycle arrest in G0/G1 phase and Caspase-3-induced apoptosis. Interestingly, the same extract showed an opposite effect when tested on PBLs and NKL cell line, in which in vitro induction of proliferation and activation of these cells was observed. The intraperitoneal injection or oral administration of LACE extract in nude mice inhibits in vivo tumor growth of Ando-2 melanoma cells and prolongs the survival day of the mice. CONCLUSION These results indicate that LACE aqueous extract has two complementary activities in vitro with potential anti-tumor therapeutic effect: cytotoxic tumor cell activity and lymphocyte activation. The LACE extract presented in vivo anti-tumoral activity in nude mice against tumor growth of Ando-2 melanoma cells.

Ultra-fast recovery from right neglect after 'awake surgery' for slow-growing tumor invading the left parietal area

It is now possible to perform resections of slow-growing tumors in awake patients. Using direct electrical stimulation, real-time functional mapping of the brain can be used to prevent the resection of essential areas near the tumor. Simple clinical observations of patients with a resection of slow-growing tumors have demonstrated substantial recovery within a few days of such 'awake surgery'. The aim of this study was to investigate the kinetics of recovery following the resection of slow-growing tumors invading the left parietal area and to focus mainly on its rapidity. Two patients were assessed by standard line bisection tests and compared with eight healthy individuals. Independently of the pure nature of the symptoms, we report that the patients rapidly and substantially recovered from pronounced right neglect. They were tested 48 hours after the surgery and the recovery was significant for both patients after less than 4 hours. Strikingly, for one patient, recovery was ultra fast and substantial in the first practice session within less than 7 minutes: it occurred without verbal feedback and was substantially retained during the following testing session. Its rapidity suggests a process of unmasking redundant networks. With the slow growth of the lesion, the contralesional hemisphere is probably progressively prepared for rapid unmasking of homologue networks. These results have major clinical implications. For patients with an invading left-side tumor, it is now clear that line bisections are required before, during, and after awake surgery to: plan the surgery, control the quality of the resection, and also optimize the rehabilitation of the patient

Notch tumor suppressor function

Cancer development results from deregulated control of stem cell populations and alterations in their surrounding environment. Notch signaling is an important form of direct cell-cell communication involved in cell fate determination, stem cell potential and lineage commitment. The biological function of this pathway is critically context dependent. Here we review the pro-differentiation role and tumor suppressing function of this pathway, as revealed by loss-of-function in keratinocytes and skin, downstream of p53 and in cross-connection with other determinants of stem cell potential and/or tumor formation, such as p63 and Rho/CDC42 effectors. The possibility that Notch signaling elicits a duality of signals, involved in growth/differentiation control and cell survival will be discussed, in the context of novel approaches for cancer therapy

Long circulating half-life and high tumor selectivity of the photosensitizer meta-tetrahydroxyphenylchlorin conjugated to polyethylene glycol in nude mice grafted with a human colon carcinoma.

In a mode of nude mice bearing a human colon carcinoma xenograft, the biodistribution and tumor localization of metatetrahydroxyphenylchlorin (m-THPC) coupled to polyethylene glycol (PEG) were compared with those of the free form of this photosensitizer used in photodynamic therapy (PDT). At different times after i.v. injection of both forms of 125I-labeled photosensitizer, m-THPC-PEG gave on average a 2-fold higher tumor uptake than free m-THPC. In addition, at early times after injection, m-THPC-PEG showed a 2-fold longer blood circulating half-life and a 4-fold lower liver uptake than free m-THPC. The tumor to normal tissue ratios of radioactivity concentrations were always higher for m-THPC-PEG than for free m-THPC at any time point studied from 2 to 96 hr post-injection. Significant coefficients of correlation between direct fluorescence measurements and radioactivity counting were obtained within each organ tested. Fluorescence microscopy studies showed that m-THPC-PEG was preferentially localized near the tumor vessels, whereas m-THPC was more diffusely distributed inside the tumor tissue. To verify whether m-THPC-PEG conjugate remained phototoxic in vivo, PDT experiments were performed 72 hr after injection and showed that m-THPC-PEG was as potent as free m-THPC in the induction of tumor regression provided that the irradiation does for m-THPC-PEG conjugate was adapted to a well-tolerated 2-fold higher level. The overall results demonstrate first the possibility of improving the in vivo tumor localization of a hydrophobic dye used for PDT by coupling it to PEG and second that a photosensitizer conjugated to a macromolecule can remain phototoxic in vivo.

Extracellular tumor-related mRNA in plasma of lymphoma patients and survival implications.

BACKGROUND We studied anomalous extracellular mRNAs in plasma from patients with diffuse large B-cell lymphoma (DLBCL) and their survival implications. mRNAs studied have been reported in the literature as markers of poor (BCL2, CCND2, MYC) and favorable outcome (LMO2, BCL6, FN1) in tumors. These markers were also analyzed in lymphoma tissues to test possible associations with their presence in plasma. METHODOLOGY/PRINCIPAL FINDINGS mRNA from 42 plasma samples and 12 tumors from patients with DLBCL was analyzed by real-time PCR. Samples post-treatment were studied. The immunohistochemistry of BCL2 and BCL6 was defined. Presence of circulating tumor cells was determined by analyzing the clonality of the immunoglobulin heavy-chain genes by PCR. In DLBCL, MYC mRNA was associated with short overall survival. mRNA targets with unfavorable outcome in tumors were associated with characteristics indicative of poor prognosis, with partial treatment response and with short progression-free survival in patients with complete response. In patients with low IPI score, unfavorable mRNA targets were related to shorter overall survival, partial response, high LDH levels and death. mRNA disappeared in post-treatment samples of patients with complete response, and persisted in those with partial response or death. No associations were found between circulating tumor cells and plasma mRNA. Absence of BCL6 protein in tumors was associated with presence of unfavorable plasma mRNA. CONCLUSIONS/SIGNIFICANCE Through a non-invasive procedure, tumor-derived mRNAs can be obtained in plasma. mRNA detected in plasma did not proceed from circulating tumor cells. In our study, unfavorable targets in plasma were associated with poor prognosis in B-cell lymphomas, mainly MYC mRNA. Moreover, the unfavorable targets in plasma could help us to classify patients with poor outcome within the good prognosis group according to IPI.

Tumor necrosis-like weak inducer of apoptosis as a proinflammatory cytokine in human adipocyte cells: up-regulation in severe obesity is mediated by inflammation but not hypoxia.

CONTEXT Adipose tissue hypoxia and endoplasmic reticulum (ER) stress may link the presence of chronic inflammation and macrophage infiltration in severely obese subjects. We previously reported the up-regulation of TNF-like weak inducer of apoptosis (TWEAK)/fibroblast growth factor-inducible 14 (Fn14) axis in adipose tissue of severely obese type 2 diabetic subjects. OBJECTIVES The objective of the study was to examine TWEAK and Fn14 adipose tissue expression in obesity, severe obesity, and type 2 diabetes in relation to hypoxia and ER stress. DESIGN In the obesity study, 19 lean, 28 overweight, and 15 obese nondiabetic subjects were studied. In the severe obesity study, 23 severely obese and 35 control subjects were studied. In the type 2 diabetes study, 11 type 2 diabetic and 36 control subjects were studied. The expression levels of the following genes were analyzed in paired samples of sc and visceral adipose tissue: Fn14, TWEAK, VISFATIN, HYOU1, FIAF, HIF-1a, VEGF, GLUT-1, GRP78, and XBP-1. The effect of hypoxia, inflammation, and ER stress on the expression of TWEAK and Fn14 was examined in human adipocyte and macrophage cell lines. RESULTS Up-regulation of TWEAK/Fn14 and hypoxia and ER stress surrogate gene expression was observed in sc and visceral adipose tissue only in our severely obese cohort. Hypoxia modulates TWEAK or Fn14 expression in neither adipocytes nor macrophages. On the contrary, inflammation up-regulated TWEAK in macrophages and Fn14 expression in adipocytes. Moreover, TWEAK had a proinflammatory effect in adipocytes mediated by the nuclear factor-kappaB and ERK but not JNK signaling pathways. CONCLUSIONS Our data suggest that TWEAK acts as a pro-inflammatory cytokine in the adipose tissue and that inflammation, but not hypoxia, may be behind its up-regulation in severe obesity.

The tumor necrosis factor-related apoptosis-inducing ligand receptors TRAIL-R1 and TRAIL-R2 have distinct cross-linking requirements for initiation of apoptosis and are non-redundant in JNK activation.

Overexpression of the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptors, TRAIL-R1 and TRAIL-R2, induces apoptosis and activation of NF-kappaB in cultured cells. In this study, we have demonstrated differential signaling capacities by both receptors using either epitope-tagged soluble TRAIL (sTRAIL) or sTRAIL that was cross-linked with a monoclonal antibody. Interestingly, sTRAIL was sufficient for induction of apoptosis only in cell lines that were killed by agonistic TRAIL-R1- and TRAIL-R2-specific IgG preparations. Moreover, in these cell lines interleukin-6 secretion and NF-kappaB activation were induced by cross-linked or non-cross-linked anti-TRAIL, as well as by both receptor-specific IgGs. However, cross-linking of sTRAIL was required for induction of apoptosis in cell lines that only responded to the agonistic anti-TRAIL-R2-IgG. Interestingly, activation of c-Jun N-terminal kinase (JNK) was only observed in response to either cross-linked sTRAIL or anti-TRAIL-R2-IgG even in cell lines where both receptors were capable of signaling apoptosis and NF-kappaB activation. Taken together, our data suggest that TRAIL-R1 responds to either cross-linked or non-cross-linked sTRAIL which signals NF-kappaB activation and apoptosis, whereas TRAIL-R2 signals NF-kappaB activation, apoptosis, and JNK activation only in response to cross-linked TRAIL.

Notch signaling in the integrated control of keratinocyte growth/differentiation and tumor suppression.

Oncogenesis is closely linked to abnormalities in cell differentiation. Notch signaling provides an important form of intercellular communication involved in cell fate determination, stem cell potential and differentiation. Here we review the role of this pathway in the integrated growth/differentiation control of the keratinocyte cell type, and the maintenance of normal skin homeostasis. In parallel with the pro-differentiation function of Notch1 in keratinocytes, we discuss recent evidence pointing to a tumor suppressor function of this gene in both mouse skin and human cervical carcinogenesis. The possibility that Notch signaling elicits signals with a duality of growth positive and negative function will be discussed.

Role of gene methylation in antitumor immune response: Implication for tumor progression

Cancer immunosurveillance theory has emphasized the role of escape mechanisms in tumor growth. In this respect, a very important factor is the molecular characterization of the mechanisms by which tumor cells evade immune recognition and destruction. Among the many escape mechanisms identified, alterations in classical and non-classical HLA (Human Leucocyte Antigens) class I and class II expression by tumor cells are of particular interest. In addition to the importance of HLA molecules, tumor-associated antigens and accessory/co-stimulatory molecules are also involved in immune recognition. The loss of HLA class I antigen expression and of co-stimulatory molecules can occur at genetic, transcriptional and post-transcriptional levels. Epigenetic defects are involved in at least some mechanisms that preclude mounting a successful host-antitumor response involving the HLA system, tumor-associated antigens, and accessory/co-stimulatory molecules. This review summarizes our current understanding of the role of methylation in the regulation of molecules involved in the tumor immune response.

Sevelamer hydrochloride: A novel treatment of hyperphosphatemia associated with tumor lysis syndrome in children

Background. Sevelamer is a phosphate-binder used effectively for the treatment of hyperphosphatemia in patients treated with dialysis. Objectives. To describe the safety of sevelamer in children with hyperphosphatemia secondary to tumor lysis syndrome and the serum phosphate concentrations observed following its administration. Procedure. A retrospective chart review of all children with leukemia/lymphoma diagnosed between November 2002 and April 2004 who received sevelamer during their initial admission was conducted. We monitored the effects of sevelamer on serum phosphate concentration, calcium/phosphate product and renal function at hours 24, 48, and 72 from sevelamer initiation. Results. Thirteen patients received sevelamer during the Study period. Their median age was 13 years (range 2.7-17.9) and eight were boys. Nine children had acute lymphoblastic leukemia, one had acute myeloid leukemia and 3 had non-Hodgkin's lymphoma. The most frequently used dose of sevelamer was 400 mg orally twice daily. The median duration of sevelamer therapy was 2 days (range 1 -7). Two children were excluded from the efficacy analysis due to concurrent use of dialysis. Mean serum phosphate levels decreased after sevelamer administration, in eleven patients, from a baseline 2.2 mmol/L +/- 0.4 (95% Cl, 1.7-3.1) to 1.1 mmol/L +/- 0.2 at hour 72 (95%Cl, 0.6-1.5). The only toxicity attributed to sevelamer was mild vomiting in three patients. Conclusions. Sevelamer appears to be effective and tolerable for the treatment of hyperphosphatemia associated with tumor lysis syndrome.

New insights into dendritic cell biology and histiocytosis through a transgenic tumor model

SUMMARY The effective development of an immune response depends on the careful interplay and the regulation between innate and adaptive immunity. As the dendritic cells (DCs) are equipped with many receptors, such as Toll-like receptors, which can detect the presence of infection by recognizing different component of bacteria, fungi and even viruses, they are the among the first cells to respond to the infection. Upon pathogen challenge, the DCs interpret the innate system activation as a maturation signal, resulting in the migration of the DCS to a draining lymph node site. There, activated DCs present efficiently antigens to naïve T cells, which are in turn activated and initiate adaptive immunity. Therefore, DCs are the main connectors between innate and adaptive immune systems. In addition to be the most efficient antigen- presenting cells, DCs play a central role in the regulation of immune responses and immune tolerance. Despite extensive research, many aspects related to DC biology are still unsolved and/or controversial. The low frequency of DCs in vivo often hamper study of DC biology and in vitro-derived DCs are not suited to address certain questions, such as the development of DC. We sought of transforming in vivo the DCs through the specific expression of an oncogene, in order to obtain unlimited numbers of these cells. To achieve this goal, transgenic mouse lines expressing the SV40 Large T oncogene under the control of the CD1 1 c promoter were generated. These transgenic mice are healthy until the age of three to four months without alterations in the DC biology. Thereafter transgenic mice develop a fatal disease that shows features of a human pathology, named histiocytosis, involving DCs. We demonstrate that the disease development in the transgenic mice correlates with a massive accumulation of transformed DCs in the affected organs. Importantly, transformed DCs are immature and fully conserve their capacity to mature in antigen presenting cells. We observe hyperproliferation of transformed DCs only in the sick transgenic mice. Surprisingly, transformed DCs do not proliferate in vitro, but transfer of the transformed DCs into immunodeficient or tolerant host leads to tumor formation. Altoghether, the transgenic mouse lines we have generated represent a valuable tumor model for human histiocytosis, and provide excellent tools to study DC biology. RESUME Le développement d'une réponse immunitaire efficace dépend d'une minutieuse interaction et régulation entre l'immunité innée et adaptative. Comme les cellules dendritiques (DCs) sont équipées de nombreux récepteurs, tels que les récepteurs Toll-like, qui peuvent détecter la présence d'une infection en reconnaissant différents composants bactériens, issus de champignons ou même viraux, elles sont parmi les premières cellules à répondre à l'infection. Suite à la stimulation induite par le pathogène, les DCs interprètent l'activation du système immunitaire inné comme un signal de maturation, résultant dans la migration des DCs vers le ganglion drainant le site d'infection. Là, les DCs actives présentent efficacement des antigènes aux cellules T, qui sont à leur tour activées et initient les systèmes d'immunité adaptative. Ainsi, les DCs forment le lien principal entre les réponses immunitaires innées et adaptatives. En plus d'être les cellules présentatrices d'antigènes les plus efficaces, les DCs jouent un rôle central dans la régulation du système immunitaire et dans le phénomène de tolérance. Malgré des recherches intensives, de nombreux aspects liés à la biologie des DCs sont encore irrésolus et/ou controversés. La faible fréquence des DCs in vivo gêne souvent l'étude de la biologie de ces cellules et les DCs dérivées in vitro ne sont pas adéquates pour adresser certaines questions, telles que le développement des DCs. Afin d'obtenir des quantités illimitées de DCs, nous avons songé à transformer in vivo les DC grâce à l'expression spécifique d'un oncogène. Afin d'atteindre ce but, nous avons généré des lignées de souris transgéniques qui expriment l'oncogène SV40 Large T sous le contrôle du promoter CD1 le. Ces souris transgéniques sont saines jusqu'à l'âge de trois à quatre mois et ne présentent pas d'altération dans la biologie des DCs. Ensuite, les souris transgéniques développent une maladie présentant les traits caractéristiques d'une pathologie humaine nommée histiocytose, qui implique les DCs. Nous montrons que le développement de cette maladie corrèle avec une accumulation massive des DCs transformées dans les organes touchés. De plus, les DCs transformées sont immatures et conservent leur capacité à différencier en cellules présentatrices d'antigène. Nous observons une hyper-prolifération des DCs transformées seulement dans les souris transgéniques malades. Etonnament, les DC transformées ne prolifèrent pas in vitro, par contre, le transfert des DCs transformées dans des hôtes immuno-déficients ou tolérant conduit à la formation de tumeurs. Globalement, les lignées de souris transgéniques que nous avons générées représentent un modèle valide pour l'histiocytose humaine, et de plus, offrent d'excellents outils pour étudier la biologie des DCs.