Therapy-Induced Stromal Senescence Promoting Aggressiveness of Prostate and Ovarian Cancer.

Cancer progression is supported by the cross-talk between tumor cells and the surrounding stroma. In this context, senescent cells in the tumor microenvironment contribute to the development of a pro-inflammatory milieu and the acquisition of aggressive traits by cancer cells. Anticancer treatments induce cellular senescence (therapy-induced senescence, TIS) in both tumor and non-cancerous cells, contributing to many detrimental side effects of therapies. Thus, we focused on the effects of chemotherapy on the stromal compartment of prostate and ovarian cancer. We demonstrated that anticancer chemotherapeutics, regardless of their specific mechanism of action, promote a senescent phenotype in stromal fibroblasts, resulting in metabolic alterations and secretion of paracrine factors, sustaining the invasive and clonogenic potential of both prostate and ovarian cancer cells. The clearance of senescent stromal cells, through senolytic drug treatment, reverts the malignant phenotype of tumor cells. The clinical relevance of TIS was validated in ovarian and prostate cancer patients, highlighting increased accumulation of lipofuscin aggregates, a marker of the senescent phenotype, in the stromal compartment of tissues from chemotherapy-treated patients. These data provide new insights into the potential efficacy of combining traditional anticancer strategies with innovative senotherapy to potentiate anticancer treatments and overcome the adverse effects of chemotherapy.

Claisened Hexafluoro Inhibits Metastatic Spreading of Amoeboid Melanoma Cells.

Metastatic melanoma is characterized by poor prognosis and a low free-survival rate. Thanks to their high plasticity, melanoma cells are able to migrate exploiting different cell motility strategies, such as the rounded/amoeboid-type motility and the elongated/mesenchymal-type motility. In particular, the amoeboid motility strongly contributes to the dissemination of highly invasive melanoma cells and no treatment targeting this process is currently available for clinical application. Here, we tested Claisened Hexafluoro as a novel inhibitor of the amoeboid motility. Reported data demonstrate that Claisened Hexafluoro specifically inhibits melanoma cells moving through amoeboid motility by deregulating mitochondrial activity and activating the AMPK signaling. Moreover, Claisened Hexafluoro is able to interfere with the adhesion abilities and the stemness features of melanoma cells, thus decreasing the in vivo metastatic process. This evidence may contribute to pave the way for future possible therapeutic applications of Claisened Hexafluoro to counteract metastatic melanoma dissemination.

Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate/Urea Nitrogen Ratio in Urine.

In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2-3) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake ofPwas1086.5 ± 361.3mg/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P/UUN ratio (p < 0.018). Patients with the highest tertile of the P/UUN ratio >71.1 mg/g presented more abundant inorganic P intake (p < 0.038).The P/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.

ETV4 promotes late development of prostatic intraepithelial neoplasia and cell proliferation through direct and p53-mediated downregulation of p21.

BACKGROUND: ETV4 is one of the ETS proteins overexpressed in prostate cancer (PC) as a result of recurrent chromosomal translocations. In human prostate cell lines, ETV4 promotes migration, invasion, and proliferation; however, its role in PC has been unclear. In this study, we have explored the effects of ETV4 expression in the prostate in a novel transgenic mouse model. METHODS: We have created a mouse model with prostate-specific expression of ETV4 (ETV4 mice). By histochemical and molecular analysis, we have investigated in these engineered mice the expression of p21, p27, and p53. The implications of our in vivo findings have been further investigated in human cells lines by chromatin-immunoprecipitation (ChIP) and luciferase assays. RESULTS: ETV4 mice, from two independent transgenic lines, have increased cell proliferation in their prostate and two-thirds of them, by the age of 10 months, developed mouse prostatic intraepithelial neoplasia (mPIN). In these mice, cdkn1a and its p21 protein product were reduced compared to controls; p27 protein was also reduced. By ChIP assay in human prostate cell lines, we show that ETV4 binds to a specific site (-704/-696 bp upstream of the transcription start) in the CDKN1A promoter that was proven, by luciferase assay, to be functionally competent. ETV4 further controls CDKN1A expression by downregulating p53 protein: this reduction of p53 was confirmed in vivo in ETV4 mice. CONCLUSIONS: ETV4 overexpression results in the development of mPIN but not in progression to cancer. ETV4 increases prostate cell proliferation through multiple mechanisms, including downregulation of CDKN1A and its p21 protein product: this in turn is mediated through direct binding of ETV4 to the CDKN1A promoter and through the ETV4-mediated decrease of p53. This multi-faceted role of ETV4 in prostate cancer makes it a potential target for novel therapeutic approaches that could be explored in this ETV4 transgenic model.

Group Activities to Promote Early Rehabilitation in an Acute Psychiatric Ward: A Relationship-Based Approach Focusing on Movies.

Our Psychiatry Institute has a long-standing tradition of providing training in the importance of relational and emotional skills and helping relationships. Here we describe techniques that are routinely used on our psychiatric ward (Maggiore della Carità Hospital, Novara, Italy) to promote early rehabilitation of acute psychiatric inpatients. We focus on the Cinema group, which is typical of our approach to informal, therapeutic group activity. Targeting social and relational issues as adjunct to treatment as usual is useful in acute settings and can begin at an early stage of hospitalization. Our intervention is designed to improve patients' coping strategies, relational and communication skills, and overall quality of life.

uPA/uPAR system activation drives a glycolytic phenotype in melanoma cells.

In this manuscript, we show the involvement of the uPA/uPAR system in the regulation of aerobic glycolysis of melanoma cells. uPAR over-expression in human melanoma cells controls an invasive and glycolytic phenotype in normoxic conditions. uPAR down-regulation by siRNA or its uncoupling from integrins, and hence from integrin-linked tyrosine kinase receptors (IL-TKRs), by an antagonist peptide induced a striking inhibition of the PI3K/AKT/mTOR/HIF1α pathway, resulting into impairment of glucose uptake, decrease of several glycolytic enzymes and of PKM2, a checkpoint that controls metabolism of cancer cells. Further, binding of uPA to uPAR regulates expression of molecules that govern cell invasion, including extracellular matrix metallo-proteinases inducer (EMPPRIN) and enolase, a glycolytyc enzyme that also serves as a plasminogen receptor, thus providing a common denominator between tumor metabolism and phenotypic invasive features. Such effects depend on the α5ß1-integrin-mediated uPAR connection with EGFR in melanoma cells with engagement of the PI3K-mTOR-HIFα pathway. HIF-1α trans-activates genes whose products mediate tumor invasion and glycolysis, thus providing the common denominator between melanoma metabolism and its invasive features. These findings unveil a unrecognized interaction between the invasion-related uPAR and IL-TKRs in the control of glycolysis and disclose a new pharmacological target (i.e., uPAR/IL-TKRs axis) for the therapy of melanoma.

Clinical Characteristics Associated with Suicide Attempts in Clinical Settings: A Comparison of Suicidal and Non-Suicidal Depressed Inpatients.

INTRODUCTION: Both psychiatrists and psychiatric nurses are involved in the psychiatric management of suicidal inpatients. One-to-one observation by qualified nurses and the accommodation of the patient in a room close to the infirmary are usually recommended. Suicidal risk should be reassessed periodically to check response to treatment. AIM: To compare the severity of depressive symptoms in depressed inpatients admitted after an attempted suicide and those admitted for any other reason and to assess the severity of suicide attempts and the management of suicidal risk in clinical settings. MATERIALS AND METHODS: We divided the sample into two subgroups: patients with a diagnosis of depression admitted because of a recent suicide attempt and depressed patients with no recent history of attempted suicide. Socio-demographic and clinical data were gathered; assessments included the Montgomery-Asberg Depression Rating Scale and the Nurses' Global Assessment of Suicide Risk (NGASR). RESULTS: Forty-six patients were recruited over a 1-year period: 20 were admitted to the hospital following a suicide attempt; the other 26 had not attempted suicide and were admitted for other depression-related reasons. Multivariate analysis revealed a correlation between use of antidepressants and recent attempted suicide. Attempting suicide was not related to the severity of depressive symptoms. In the recent suicide attempt subgroup, NGASR suicide risk levels were lower at discharge than at admission. Patients with a recent history of attempted suicide had a higher number of suicide attempts in their clinical history than patients with no recent history of attempted suicide. CONCLUSION: There were no correlations between psychiatric diagnosis, severity of depressive symptoms, and recent suicide attempt. Antidepressant therapy protected against suicide attempts. History of suicide attempts was one of the best predictors of recent attempted suicide. A more thorough understanding of the complex phenomenon of suicide and the reasons for suicidal behavior is needed.

Tumor-tropic endothelial colony forming cells (ECFCs) loaded with near-infrared sensitive Au nanoparticles: A "cellular stove" approach to the photoablation of melanoma.

In the photothermal treatments (PTs) of tumor, the localization of a high number of near-infrared (NIR) absorbing gold nanoparticles in the tumor mass is still a challenging issue. Here, we propose a promising strategy to deliver therapeutic chitosan-coated gold nanoparticles to tumor cells as hidden cargo of Endothelial Colony Forming Cells (ECFCs) endowed with an innate tumor-tropism. Remarkably, ECFC gold enrichement doesn't affect cell viability and preserves the endothelial lineage characteristics such as capillary morphogenesis and cell migration. We demonstrate that heavily Au-doped ECFCs are able to efficiently warm up the tumor environment, and kill the cancer cells via hyperthermic heating both in vitro as well as in vivo. Thus, we show an excellent thermotransductive property of gold enriched ECFCs and their capability to kill melanoma cells at moderate NIR light intensities.

HDAC1 controls CIP2A transcription in human colorectal cancer cells.

This work describes the effectiveness of HDAC-inhibitor (S)-2 towards colorectal cancer (CRC) HCT116 cells in vitro by inducing cell cycle arrest and apoptosis, and in vivo by contrasting tumour growth in mice xenografts. Among the multifaceted drug-induced events described herein, an interesting link has emerged between the oncoprotein histone deacetylase HDAC1 and the oncogenic Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) which is overexpressed in several cancers including CRCs. HDAC1 inhibition by (S)-2 or specific siRNAs downregulates CIP2A transcription in three different CRC cell lines, thus restoring the oncosuppressor phosphatase PP2A activity that is reduced in most cancers. Once re-activated, PP2A dephosphorylates pGSK-3ß(ser9) which phosphorylates ß-catenin that remains within the cytosol where it undergoes degradation. The decreased amount/activity of ß-catenin transcription factor prompts cell growth arrest by diminishing c-Myc and cyclin D1 expression and abrogating the prosurvival Wnt/ß-catenin signaling pathway. These results are the first evidence that the inhibition of HDAC1 by (S)-2 downregulates CIP2A transcription and unleashes PP2A activity, thus inducing growth arrest and apoptosis in CRC cells.

Immigrants' Pathways to Outpatient Mental Health: Are there Differences with the Native Population?

A poor use of mental health services has been described in immigrants. We compared the sociodemographic, clinical and treatment features of immigrants and natives attending a Community Mental Health Centre (CMHC). 191 immigrants and 191 randomly selected natives applying to the Borgomanero CMHC between 1 January 2003 and 31 August 2013 were compared. Our sample consisted mainly of the so-called "economic" immigrant. Adjustment disorders and reaction to stress were the most frequent diagnoses; in most cases symptoms onset occurred after migration. Although treatment features overlapped in the two groups (duration, number of contacts), immigrants showed a higher frequency of treatment dropout. While it is necessary to improve access to mental health services for immigrants, for the "economic" immigrant it may be more important to focus on establishing a therapeutic relationship that can be experienced as reliable and trustworthy. The finding of similar pathways to access the CMHC in natives and immigrants is encouraging.

The effectiveness of a new approach using movies in the training of medical students.

INTRODUCTION: The use of movies in medical (particularly psychiatric) education has been often limited to portraits of mental illness and psychiatrists. The Psychiatric Institute of the Università del Piemonte Orientale has a longstanding tradition of working with/on movies according to a method developed by Eugenio Torre, using dynamic images as educational incitements. Our aim is to describe the preliminary results on the impact of this intervention in medical students. METHODS: The cinemeducation project lasted 6 months, and included 12 meetings. Forty randomly selected participants were assessed with: Attitudes Towards Psychiatry Scale (ATP-30), Social Distance Scale (SDS), Interpersonal Reactivity Index (IRI), and Toronto Alexithymia Scale (TAS), both at baseline and after 6 months, when the workshop was concluded. RESULTS: A significant increase was found in the ATP-30 score, and a reduction of the SDS and IRI-Personal Distress scale scores. CONCLUSIONS: Informal feedback from participants was strongly positive. Preliminary results from the assessment of participants are encouraging. Students' attitudes towards psychiatry and ability to tolerate anxiety when experiencing others' distress improved, while stigma decreased. The evocative power of movie dynamic images, developed in the group and integrated with the help of the group leader, can enrich students' knowledge, both from a cognitive and emotional standpoint.

Endothelial sphingosine kinase/SPNS2 axis is critical for vessel-like formation by human mesoangioblasts.

UNLABELLED: The interaction between endothelial cells and pericytes is crucial for the stabilization of newly formed vessels in angiogenesis. The comprehension of the mechanisms regulating pericyte recruitment might open therapeutical perspectives on vascular-related pathologies. Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid that derives from sphingomyelin catabolism and regulates biological functions in cell survival, proliferation, and differentiation. In this study, we aimed to identify the role of S1P axis in the intercellular communication between human mesenchymal progenitor mesoangioblasts (MAB) and endothelial cells (human microvascular endothelial cells (H-MVEC)) in the formation of capillary-like structures. We demonstrated that the S1P biosynthetic pathway brought about by sphingosine kinases (SK) SK1 and SK2 as well as spinster homolog 2 (SPNS2) transporter in H-MVEC is crucial for MAB migration measured by Boyden chambers and for the formation and stabilization of capillary-like structures in a 3D Matrigel culture. Moreover, the conditioned medium (CM) harvested from H-MVEC, where SK1, SK2, and SPNS2 were down-regulated, exerted a significantly diminished effect on MAB capillary morphogenesis and migration. Notably, we demonstrated that S1P1 and S1P3 receptors were positively involved in CM-induced capillary-like formation and migration, while S1P2 exerted a negative role on CM-induced migratory action of MAB. Finally, SK inhibition as well as MAB S1P1 and S1P3 down-regulation impaired H-MVEC-MAB cross-talk significantly reducing in vivo angiogenesis evaluated by Matrigel plug assay. These findings individuate novel targets for the employment of MAB in vascular-related pathologic conditions. KEY MESSAGE: • Down-regulation of SK1/2 in H-MVEC impaired vessel formation when cultured with MAB. • H-MVEC SPNS2 is critical for morphogenesis and migration induced by H-MVEC CM of MAB. • CM from SK1- and SK2-siRNA H-MVEC impaired morphogenesis and migration of MAB. • S1P1/3 were involved on CM-induced morphogenesis and migration of MAB. • Matrigel plug assay showed the role of S1P axis in MAB-endothelial cell interaction.

Suicide attempts and emergency room psychiatric consultation.

BACKGROUND: Suicidal behaviours are major public health concerns worldwide. They are associated with risk factors that vary with age and gender, occur in combination, and may change over time. The aim of our study was to investigate how frequently patients visiting a hospital emergency room (ER) require a psychiatric consultation for attempted suicide, and to outline the characteristics of this population. METHODS: Determinants of emergency room visits for psychiatric reasons were studied prospectively from 2008 to 2011 at the "Maggiore" Hospital in Novara. RESULTS: 280 out of 1888 patients requiring psychiatric consultation were referred to the ER because of suicide attempt. Suicide attempters were more often female. The rate of suicide attempters among Italian people was 14.2%, compared to 19.5% in foreigners. Subjects living with parents or own family and those having a permanent job had a higher frequency of suicide attempt. Suicide attempts were more frequent among patients with a history of psychiatric disorders; nonetheless, suicide attempts were more common among those who had not previously been hospitalized in a psychiatric ward or were not under the care of a psychiatrist. The multivariate analysis found that female gender was a risk factor for suicide attempt, while being in the colder months of the year and, surprisingly, unemployment were protective factors. CONCLUSIONS: A better understanding of patients referring to the ER due to attempted suicide may allow the identification of at-risk subjects and the implementation of targeted treatment approaches.

Psychopathology, personality and theory of mind in a sample of university students.

OBJECTIVE: To assess psychopathology, personality and theory of mind in a sample of university students, and to analyse their correlation with socio-demographic and academic factors. MATERIALS AND METHODS: Socio-demographic and academic data were collected from 228 students. They completed the Eysenck Personality Questionnaire-R, Symptom Checklist-90-R (SCL-90-L) and Theory of Mind (ToM) test. RESULTS: Elevated psychological distress was found in 38.6% of students; 30.3% had an abnormal ToM score. Students with an abnormal ToM score had a significantly lower probability than those with normal ToM test to repeat an exam three times or more. Not being married and receiving psychiatric care significantly influenced the probability of repeating an exam. Abnormal ToM students had specific features as far as major and SCL-90-R scores are concerned. CONCLUSIONS: A correlation was found among ToM performance and some indicators of academic performance. Students with ToM scores under the cut-off reported more psychopathological symptoms and distress. Implications are discussed

Melanoma cell therapy: Endothelial progenitor cells as shuttle of the MMP12 uPAR-degrading enzyme.

The receptor for the urokinase-type plasminogen activator (uPAR) accounts for many features of cancer progression, and is therefore considered a target for anti-tumoral therapy. Only full length uPAR mediates tumor progression. Matrix-metallo-proteinase-12 (MMP12)-dependent uPAR cleavage results into the loss of invasion properties and angiogenesis. MMP12 can be employed in the field of "targeted therapies" as a biological drug to be delivered directly in patient's tumor mass. Endothelial Progenitor Cells (EPCs) are selectively recruited within the tumor and could be used as cellular vehicles for delivering anti-cancer molecules. The aim of our study is to inhibit cancer progression by engeneering ECFCs, a subset of EPC, with a lentivirus encoding the anti-tumor uPAR-degrading enzyme MMP12. Ex vivo manipulated ECFCs lost the capacity to perform capillary morphogenesis and acquired the anti-tumor and anti-angiogenetic activity. In vivo MMP12-engineered ECFCs cleaved uPAR within the tumor mass and strongly inhibited tumor growth, tumor angiogenesis and development of lung metastasis. The possibility to exploit tumor homing and activity of autologous MMP12-engineered ECFCs represents a novel way to combat melanoma by a "personalized therapy", without rejection risk. The i.v. injection of radiolabelled MMP12-ECFCs can thus provide a new theranostic approach to control melanoma progression and metastasis.

Sex differences in first-admission psychiatric inpatients with and without a comorbid substance use disorder.

OBJECTIVES: We assessed sex differences in a sample of first-admission psychiatric inpatients with and without comorbid substance use disorder (SUD) to identify possible risk factors and targets for sex-tailored treatment interventions. METHODS: A retrospective study of first admissions to the University Psychiatry Ward, "Maggiore della Carità" Hospital, Novara, Italy, between 2003 and 2012 was accomplished. The clinical charts of patients with (N = 362) and without comorbid SUD (N = 1111) were reviewed. RESULTS: Differences in employment, educational, and marital statuses were found between male and female psychiatric patients with and without comorbid SUD. Having a degree was a protective factor for males, whereas it was a risk factor for females. Being divorced and having family problems were both risk factors for comorbidity in females. Regarding the diagnosis, results overlapped in males and females, and both affective and other disorders were risk factors for a comorbid SUD. CONCLUSIONS: A significant difference between male and female psychiatric patients with a comorbid SUD was the males' overall poorer psychosocial functioning. Marital status and family problems were risk factors for comorbid SUD in females. Both males and females showed various pathways of access to and choices of substances and, eventually, experienced different impacts on their lives. Hospitalization might help to set up a targeted intervention for patients with comorbidity, while accounting for sex differences. With respect to males, a treatment approach focused on the substance alone might help improve their functioning; females might have a greater benefit from a treatment approach focused on distress, family problems, and relational issues.

[Consultation-liaison psychiatry: strategy for care, opportunity for training]. / Psychiatrie de liaison: stratégie de soins, occasion de formation.

The liaison psychiatry defines itself as way to comprehend the psychological aspects in any situation of care, and in particular in the context of somatic care. The identification of the psychic processes, which can influence the diagnosis and the outcome of a somatic disease, is essential to adequately and globally take care of the individual. At the same time, training in the Help relationship allows to identify the difficulties of nursing, which is very often source of exhaustion and burn-out.

An observational study of Venlafaxine and CYP2D6 in clinical practice.

BACKGROUND: Venlafaxine (V) is a serotonin-norepinephrine selective reuptake inhibitor, mainly metabolized by cytochrome P4502D6 (CYP2D6). CYP2D6 polymorphisms result in a variety of phenotypes: poor (PMs), intermediate (IMs), extensive (EMs), and ultrarapid metabolizers (UMs). PMs usually show poor tolerance to drugs metabolized by CYP2D6, while UMs need greater doses. The aim of this study was to evaluate the impact of CYP2D6 genotype on V dosage, therapeutic response, and side effects in a clinical outpatient setting. METHODS: 47 patients with Major Depressive Disorder, treated with V 75 - 300 mg/day, underwent CYP2D6 genotyping using the INFINITI-CYP2D6 assay. Duration of treatment and clinical outcome (Clinical Global Impression [CGI] effectiveness index) were assessed. RESULTS: CGI assessment was performed after 6 weeks, 6 months, and 1 year of treatment with a V median dose of 150 mg/day. CYP2D6 genotyping resulted in 1 PM, 3 IMs, 42 EMs, and 1 UM. The UM took the greatest V dose (375 mg) without side effects; IMs/PMs took moderate/high doses of V (150 - 300 mg) without adverse effects; EMs displayed high response variability. CONCLUSIONS: PM/IM patients responded to V differently than expected according to genotype. However, the UM patient responded to a dosage higher than the usual therapeutic range and without developing side effects, suggesting an association between CYP2D6 gene duplication and the therapeutic efficacy of venlafaxine. The CYP2D6 genotyping may thus provide clinicians with a potential explanation for those patients requiring greater doses of CYP2D6 substrates in order to obtain the same therapeutic efficacy.

Contribution of acidic melanoma cells undergoing epithelial-to-mesenchymal transition to aggressiveness of non-acidic melanoma cells.

Tumor cell plasticity largely depends on epithelial-to-mesenchymal transition (EMT) and its reversion. It was ascertained that EMT characterizes disease progression, including melanoma malignancy. As most solid tumors, melanoma shows extracellular acidosis, we analyse the impact of acidic environment on the EMT development in human melanoma cells. Melanoma cells were exposed to an acidic extracellular environment (pH 6.7) and tested for EMT markers. We found that acidic cells express a significant up-regulation of mesenchymal markers (N-cadherin, Vimentin), transcription factors (Twist, NF-κB) and a significant, although modest, reduction of E-cadherin expression. Acidic cell also express an increased invasiveness through Matrigel associated with an up-regulation of MMP-9 activity. When we injected acidic cells intravenously into immunodeficient animals, we found a number of lung micrometastases not different from non-acidic cells. Indeed, they show a partial G1 cell cycle arrest, which might interfere with the growth of lung colonies. When we investigated the in vitro invasiveness and lung colonization of a mixed population of acidic and non acidic melanoma cells, we found that acidic cells promote in vitro invasiveness of non-acidic cells and this cooperation leads to an higher migration rate than acidic cells. Moreover, acidic cells cooperate for a better lung colonization of non-acidic cells, that represent the greater part of cells participating to lung micrometastases. We found evidence that acidity triggers in melanoma cells an EMT program, which although "incomplete", potentiates migration rate and development of lung colonies into immunodeficient host of cells grown in standard pH.

Hypoxia-resistant profile implies vulnerability of cancer stem cells to physiological agents, which suggests new therapeutic targets.

We have previously shown that peculiar metabolic features of cell adaptation and survival in hypoxia imply growth restriction points that are typical of embryonic stem cells and disappear with differentiation. Here we provide evidence that such restrictions can be exploited as specific antiblastic targets by physiological factors such as pyruvate, tetrahydrofolate, and glutamine. These metabolites act as powerful cytotoxic agents on cancer stem cells (CSCs) when supplied at doses that perturb the biochemical network, sustaining the resumption of aerobic growth after the hypoxic dormant state. Experiments were performed in vivo and in vitro using CSCs obtained from various anaplastic tumors: human melanoma, leukemia, and rat hepatoma cells. Pretreatment of melanoma CSCs with pyruvate significantly reduces their self-renewal in vitro and tumorigenicity in vivo. The metabolic network underlying the cytotoxic effect of the physiological factors was thoroughly defined, principally using AH130 hepatoma, a tumor spontaneously reprogrammed to the embryonic stem stage. This network, based on a tight integration of aerobic glycolysis, cellular redox state, and folate metabolism, is centered on the cellular NADP/NADPH ratio that controls the redox pathway of folate utilization in purine synthesis. On the whole, this study indicates that pyruvate, FH 4, and glutamine display anticancer activity, because CSCs are committed to survive and maintain their stemness in hypoxia. When CSC need to differentiate and proliferate, they shift from anaerobic to aerobic status, and the few mitochondria available makes them susceptible to the injury of the above physiological factors. This vulnerability might be exploited for novel therapeutic treatments.