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Introduction: Calcium silicate (CS) dental cements have numerous clinical indications in dentistry including pulp capping, root end surgery, perforation repair and apexification/apexogenesis treatment. Materials and methods: Novel CS based dental cement with incorporation of SrCO3 radiopacifier named ALBO-DENT was used as an experimental cement material while Portland cement (Aalborg, Denmark) and ProRoot MTA (Tulsa Dental, USA) were used as controls. The radiopacity evaluation was performed using digital Trophy Radiographic system with an intention to precisely determine the minimum of radiopaque agent needed to confer to ISO radiopacity requirement. Thereafter, biocompatibility of material was tested in in vitro conditions in mouse fibrosarcoma L929 cell culture treated with materials' extracts. Cell morphology was observed using phase-contrast microscopy, while cell viability was measured using crystal violet (CV) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assays. Results: Radiopacity evaluation revealed that 30%wt addition of SrCO3 was necessary to achieve satisfactory radiopacity (3.45 mm Al). Cytotoxicity analysis using CV and MTT assays revealed that pure extracts of ALBO-DENT presented superior biocompatibility when compared to PC and MTA controls while serial dilutions of experimental cements' extracts as well as that of PC and MTA did not influence L929 cell viability. Conclusions Novel formulation of CS cement - ALBO-DENT presented satisfactory radiopacity and adequate biocompatibility.

Introduction: The accumulation of alpha-synuclein (ASYN) in susceptible neurons is considered to be a major contributing factor in pathogenesis of Parkinson's disease. Although ASYN was considered as an intracellular protein, recent data suggest that it can be detected extracellularly. Autophagy plays an important role in ASYN degradation; therefore, impairment of autophagy could be an important contributor to ASYN accumulation. ATG (autophagy-related genes) proteins function at several physiologically continuous steps in autophagy, and ATG7 is considered as essential in autophagosome formation and maturation. Aim: The aim of this study was to investigate the role of autophagy in neurotoxicity, caused by extracellular ASYN. Material and methods: All experiments were conducted in all-trans retinoic acid-differentiated human neuroblastoma SH-SY5Y cells, that were exposed to extracellular ASYN. The presence of extracellular ASYN and the expression of autophagy markers, beclin-1 and LC3-II, were monitored using immunoblotting. Transfection, with small interfering RNA (siRNA), was used to knock down ATG7 gene. Cell viability was assessed using crystal violet dye exclusion assay. Results: Extracellular ASYN caused significant loss of viability in differentiated SH-SY5Y cells, accompanied by the increase in expression of beclin-1 and in conversion of LC3-I to autophagosome-associated LC3-II. The RNA interference-mediated knock-down of ATG7 increased the sensitivity of SH-SY5Y cells to the extracellular ASYN-induced toxicity. Conclusion: Extracellular ASYN caused loss of viability in differentiated SH-SY5Y cells accompanied by autophagy induction. Having in mind that inhibition of autophagy, through ATG7 knock-down increased cell death, we can conclude that autophagy could have a protective role in the harmful effect of extracellular ASYN.

Numerous beneficial effects of food restriction on aging and age-related pathologies are well documented. It is also well-established that both short- and long-term food restriction regimens induce elevated circulating levels of glucocorticoids, stress-induced hormones produced by adrenal glands that can also exert deleterious effects on the brain. In the present study, we examined the effect of long-term food restriction on the glucocorticoid hormone/glucocorticoid receptor (GR) system in the cortex during aging, in 18- and 24-month-old rats. Corticosterone level was increased in the cortex of aged ad libitum-fed rats. Food restriction induced its further increase, accompanied with an increase in the level of 11β-hydroxysteroid dehydrogenase type 1. However, alterations in the level of GR phosphorylated at Ser 232 were not detected in animals on food restriction, in line with unaltered CDK5 level, the decrease of Hsp90, and an increase in a negative regulator of GR function, FKBP51. Moreover, our data revealed that reduced food intake prevented age-related increase in the levels of NFκB, gfap , and bax , confirming its anti-inflammatory and anti-apoptotic effects. Along with an increase in the levels of c-fos , our study provides additional evidences that food restriction affects cortical responsiveness to glucocorticoids during aging.

We investigated the interplay between the intracellular energy sensor AMP-activated protein kinase (AMPK), prosurvival kinase Akt, oxidative stress, and autophagy in the cytotoxicity of parkinsonian neurotoxin 1-methyl-4-phenyl piridinium (MPP+) towards SH-SY5Y human neuroblastoma cells. MPP+-mediated oxidative stress, mitochondrial depolarization, and apoptotic cell death were associated with rapid (within 2 h) activation of AMPK, its target Raptor, and prosurvival kinase Akt. Antioxidants N-acetylcysteine and butylated hydroxyanisole suppressed MPP+-induced cytotoxicity, AMPK, and Akt activation. A genetic or pharmacological inhibition of AMPK increased MPP+-triggered production of reactive oxygen species and cell death, and diminished Akt phosphorylation, while AMPK activation protected SH-SY5Y cells from MPP+. On the other hand, genetic or pharmacological inactivation of Akt stimulated MPP+-triggered oxidative stress and neurotoxicity, but did not affect AMPK activation. At later time-points (16-24 h), MPP+ inhibited the main autophagy repressor mammalian target of rapamycin, which coincided with the increase in the levels of autophagy marker microtubule-associated protein 1 light-chain 3B. MPP+ also increased the concentration of a selective autophagic target sequestosome-1/p62 and reduced the levels of lysosomal-associated membrane protein 1 and cytoplasmic acidification, suggesting that MPP+-induced autophagy was coupled with a decrease in autophagic flux. Nevertheless, further pharmacological inhibition of autophagy sensitized SH-SY5Y cells to MPP+-induced death. Antioxidants and AMPK knockdown reduced, whereas genetic inactivation of Akt potentiated neurotoxin-triggered autophagy. These results suggest that MPP+-induced oxidative stress stimulates AMPK, which protects SH-SY5Y cells through early activation of antioxidative Akt and late induction of cytoprotective autophagy., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Glioblastoma multiforme (GMB) is the most malignant of all brain tumors with poor prognosis. Anticancer potential of xanthones, bioactive compounds found in Gentiana dinarica, is well-documented. Transformation of G. dinarica roots with Agrobacterium rhizogenes provides higher xanthones accumulation, which enables better exploitation of these anticancer compounds., Hypothesis/purpose: The aim of this study was to investigate antiglioma effect of three different G. dinarica extracts: E1-derived from untransformed roots, E2-derived from roots transformed using A. rhizogenes strain A4M70GUS, and E3-derived from roots transformed using A. rhizogenes strain 15834/PI. Further, mechanisms involved in anticancer potential of the most potent extract were examined in detail, and its active component was determined., Methods: The cell viability was assessed using MTT and crystal violet test. Cell cycle analysis, the expression of differentiation markers, the levels of autophagy, and oxidative stress were analyzed by flow cytometry. Autophagy and related signaling pathways were assessed by immunoblotting., Results: E3, in contrast to E1 and E2, strongly reduced growth of U251 human glioblastoma cells, triggered cell cycle arrest in G 2 /M phase, changed cellular morphology, and increased expression of markers of differentiated astrocytes (glial fibrillary acidic protein) and neurons (β-tubulin). E3 stimulated autophagy, as demonstrated by enhanced intracellular acidification, increased microtubule-associated light chain 3B (LC3-I) conversion to autophagosome associated LC3-II, and decreased level of selective autophagy target p62. Induction of autophagy was associated with Akt-dependent inhibition of main autophagy suppressor mammalian target of rapamycin (mTOR). Both genetic and pharmacological inhibition of autophagy suppressed the expression of differentiation markers, but had no effect on cell cycle arrest in E3-treated cells. E3 stimulated oxidative stress, and antioxidants vitamin E and N-acetyl cysteine inhibited autophagy and differentiation of E3-treated U251 cells. The most prevalent compound of E3, xanthone aglycone norswertianin, also arrested glioblastoma cell proliferation in G 2 /M phase and induced glioblastoma cell differentiation through induction of autophagy and oxidative stress., Conclusion: These results indicate that E3 and its main active component norswertianin may serve as a potential candidate for differentiation therapy of glioblastoma., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

We investigated the in vitro and in vivo anticancer effect of combining lysosomal membrane permeabilization (LMP)-inducing agent N-dodecylimidazole (NDI) with glycolytic inhibitor 2-deoxy-d-glucose (2DG). NDI-triggered LMP and 2DG-mediated glycolysis block synergized in inducing rapid ATP depletion, mitochondrial damage, and reactive oxygen species production, eventually leading to necrotic death of U251 glioma cells but not primary astrocytes. NDI/2DG-induced death of glioma cells was partly prevented by lysosomal cathepsin inhibitor E64 and antioxidant α-tocopherol, suggesting the involvement of LMP and oxidative stress in the observed cytotoxicity. LMP-inducing agent chloroquine also displayed a synergistic anticancer effect with 2DG, whereas glucose deprivation or glycolytic inhibitors iodoacetate and sodium fluoride synergistically cooperated with NDI, thus further indicating that the anticancer effect of NDI/2DG combination was indeed due to LMP and glycolysis block. The two agents synergistically induced ATP depletion, mitochondrial depolarization, oxidative stress, and necrotic death also in B16 mouse melanoma cells. Moreover, the combined oral administration of NDI and 2DG reduced in vivo melanoma growth in C57BL/6 mice by inducing necrotic death of tumor cells, without causing liver, spleen, or kidney toxicity. Based on these results, we propose that NDI-triggered LMP causes initial mitochondrial damage that is further increased by 2DG due to the lack of glycolytic ATP required to maintain mitochondrial health. This leads to a positive feedback cycle of mitochondrial dysfunction, ATP loss, and reactive oxygen species production, culminating in necrotic cell death. Therefore, the combination of LMP-inducing agents and glycolysis inhibitors seems worthy of further exploration as an anticancer strategy., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

We explored the interplay between the intracellular energy sensor AMP-activated protein kinase (AMPK), extracellular signal-regulated kinase (ERK), and autophagy in phorbol myristate acetate (PMA)-induced neuronal differentiation of SH-SY5Y human neuroblastoma cells. PMA-triggered expression of neuronal markers (dopamine transporter, microtubule-associated protein 2, β-tubulin) was associated with an autophagic response, measured by the conversion of microtubule-associated protein light chain 3 (LC3)-I to autophagosome-bound LC3-II, increase in autophagic flux, and expression of autophagy-related (Atg) proteins Atg7 and beclin-1. This coincided with the transient activation of AMPK and sustained activation of ERK. Pharmacological inhibition or RNA interference-mediated silencing of AMPK suppressed PMA-induced expression of neuronal markers, as well as ERK activation and autophagy. A selective pharmacological blockade of ERK prevented PMA-induced neuronal differentiation and autophagy induction without affecting AMPK phosphorylation. Conversely, the inhibition of autophagy downstream of AMPK/ERK, either by pharmacological agents or LC3 knockdown, promoted the expression of neuronal markers, thus indicating a role of autophagy in the suppression of PMA-induced differentiation of SH-SY5Y cells. Therefore, PMA-induced neuronal differentiation of SH-SY5Y cells depends on a complex interplay between AMPK, ERK, and autophagy, in which the stimulatory effects of AMPK/ERK signaling are counteracted by the coinciding autophagic response. Phorbol myristate acetate (PMA) induces the expression of dopamine transporter, microtubule-associated protein 2, and β-tubulin, and subsequent neuronal differentiation of SH-SY5Y neuroblastoma cells through AMP-activated protein kinase (AMPK)-dependent activation of extracellular signal-regulated kinase (ERK). The activation of AMPK/ERK axis also induces the expression of beclin-1 and Atg7, and increases LC3 conversion, thereby triggering the autophagic response that counteracts differentiation process., (© 2014 International Society for Neurochemistry.)

We investigated the ability of 19 recently synthesized arylpiperazine compounds to protect human SH-SY5Y neuroblastoma cells from the neurotoxin 6-hydroxydopamine (6-OHDA). The compound with the most potent neuroprotective action was N-{3-[2-(4-phenyl-piperazin-1-yl)-ethyl]-phenyl}-picolinamide (6b), which reduced 6-OHDA-induced apoptotic death through stabilization of mitochondrial membrane and subsequent prevention of superoxide production, caspase activation and DNA fragmentation. 6-OHDA-triggered autophagic response was also reduced by 6b, which prevented inactivation of the main autophagy repressor mTOR, upregulation of proautophagic beclin-1, conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to autophagosome-associated LC3-II, as well as intracytoplasmic acidification induced by 6-OHDA. The inhibition of autophagy using LC3β gene silencing or pharmacological autophagy blockers 3-methyladenine or bafilomycin A1, mimicked the cytoprotective effect of 6b. While the treatment with 6b had no effect on the phosphorylation of proapoptotic MAP kinases ERK and JNK, it markedly increased the phosphorylation of the prosurvival kinase Akt in 6-OHDA-treated cells. Akt inhibitor DEBC or RNA interference-mediated Akt silencing reduced the ability of 6b to block 6-OHDA-triggered apoptotic and autophagic responses, thus confirming their dependency on Akt activation. The cytoprotective effect of 6b was also observed in 6-OHDA-treated neuronal PC12 cells, but not in SH-SY5Y or PC12 cells exposed to 1-methyl-4-phenylpyridinium, indicating that the observed neuroprotection was dependent on the cytotoxic stimulus. Because of the ability to prevent 6-OHDA induced apoptotic/autophagic cell death through activation of Akt, the investigated arylpiperazines could be potential candidates for treatment of neurodegenerative diseases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The aim of the study was to investigate serum concentrations of interleukin (IL)-17 and IL-17-inducing cytokines IL-23 and transforming growth factor (TGF)-β, as well as IL-17 single nucleotide polymorphism (SNP) rs2275913 in patients with primary antiphospholipid syndrome (PAPS). We studied fifty patients with PAPS and fifty age- and sex-matched healthy controls. The cytokine levels were measured by ELISA, while the rs2275913 SNP located in promoter region of IL-17 gene was genotyped using real-time PCR. The significantly higher levels of IL-17 (p=0.002), IL-23 (p<0.001) and TGF-β (p=0.042) were found in PAPS patients (median 13.1, 9.4, and 125.6 pg/ml, respectively) compared to the control group (6.8, 4.9 and 44.4 pg/ml). There was a significant positive correlation between concentrations of IL-17 and IL-23 (r=0.540, p<0.001), but not between those of IL-17 and TGF-β. No statistically significant differences were observed in the distribution of genotypes and alleles of the IL-17 rs2275913 variants in patients with PAPS compared to healthy subjects. The blood concentrations of IL-17 did not differ in subjects with different rs2275913 genotypes or patients with or without antiphospholipid antibodies. Finally, a trend toward higher IL-17 levels (p=0.063) and the significantly higher IL-17 concentrations (p=0.012) were observed in PAPS patients with deep vein thrombosis and thrombocytopenia, respectively. These data demonstrate that IL-23/IL-17 axis, stimulated independently of TGF-β increase IL-17A gene polymorphism and antiphospholipid antibody production, might contribute to vascular manifestations of PAPS., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

The role of the main intracellular energy sensor adenosine monophosphate (AMP)-activated protein kinase (AMPK) in the induction of autophagic response and cell death was investigated in SH-SY5Y human neuroblastoma cells exposed to the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA). The induction of autophagy in SH-SY5Y cells was demonstrated by acridine orange staining of intracellular acidic vesicles, the presence of autophagosome- and autophagolysosome-like vesicles confirmed by transmission electron microscopy, as well as by microtubule-associated protein 1 light-chain 3 (LC3) conversion and p62 degradation detected by immunoblotting. 6-OHDA induced phosphorylation of AMPK and its target Raptor, followed by the dephosphorylation of the major autophagy inhibitor mammalian target of rapamycin (mTOR) and its substrate p70S6 kinase (S6K). 6-OHDA treatment failed to suppress mTOR/S6K phosphorylation and to increase LC3 conversion, p62 degradation and cytoplasmatic acidification in neuroblastoma cells in which AMPK expression was downregulated by RNA interference. Transfection of SH-SY5Y cells with AMPK or LC3β shRNA, as well as treatment with pharmacological autophagy inhibitors suppressed, while mTOR inhibitor rapamycin potentiated 6-OHDA-induced oxidative stress and apoptotic cell death. 6-OHDA induced phosphorylation of p38 mitogen-activated protein (MAP) kinase in an AMPK-dependent manner, and pharmacological inhibition of p38 MAP kinase reduced neurotoxicity, but not AMPK activation and autophagy triggered by 6-OHDA. Finally, the antioxidant N-acetyl cysteine antagonized 6-OHDA-induced activation of AMPK, p38 and autophagy. These data suggest that oxidative stress-mediated AMPK/mTOR-dependent autophagy and AMPK/p38-dependent apoptosis could be valid therapeutic targets for neuroprotection., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Purpose: To investigate the ability of chloroquine, a lysosomotropic autophagy inhibitor, to enhance the anticancer effect of nutrient deprivation., Methods: Serum-deprived U251 glioma, B16 melanoma and L929 fibrosarcoma cells were treated with chloroquine in vitro. Cell viability was measured by crystal violet and MTT assay. Oxidative stress, apoptosis/necrosis and intracellular acidification were analyzed by flow cytometry. Cell morphology was examined by light and electron microscopy. Activation of AMP-activated protein kinase (AMPK) and autophagy were monitored by immunoblotting. RNA interference was used for AMPK and LC3b knockdown. The anticancer efficiency of intraperitoneal chloroquine in calorie-restricted mice was assessed using a B16 mouse melanoma model., Results: Chloroquine rapidly killed serum-starved cancer cells in vitro. This effect was not mimicked by autophagy inhibitors or LC3b shRNA, indicating autophagy-independent mechanism. Chloroquine-induced lysosomal accumulation and oxidative stress, leading to mitochondrial depolarization, caspase activation and mixed apoptotic/necrotic cell death, were prevented by lysosomal acidification inhibitor bafilomycin. AMPK downregulation participated in chloroquine action, as AMPK activation reduced, and AMPK shRNA mimicked chloroquine toxicity. Chloroquine inhibited melanoma growth in calorie-restricted mice, causing lysosomal accumulation, mitochondrial disintegration and selective necrosis of tumor cells., Conclusion: Combined treatment with chloroquine and calorie restriction might be useful in cancer therapy.

We investigated the cytotoxicity of recently synthesized (S,S)-ethylendiamine-N,N'-di-2-(3-cyclohexyl)propanoic acid esters toward human leukemic cell lines and healthy blood mononuclear cells. Cell viability was assessed by acid phosphatase assay, apoptosis, and differentiation were analyzed by flow cytometry and electron microscopy, while intracellular localization of apoptosis-inducing factor (AIF) was determined by immunoblotting. It was demonstrated that methyl, ethyl, and n-propyl esters were toxic to HL-60, REH, MOLT-4, KG-1, JVM-2, and K-562 leukemic cell lines, while the nonesterified parental compound and n-butyl ester were devoid of cytotoxic action. The ethyl ester exhibited the highest cytotoxic activity (IC₅₀ 10.7 μM-45.4 μM), which was comparable to that of the prototypical anticancer drug cisplatin. The observed cytotoxic effect in HL-60 cells was associated with an increase in superoxide production and mitochondrial membrane depolarization, leading to apoptotic cell death characterized by phosphatidylserine externalization and DNA fragmentation in the absence of autophagic response. DNA fragmentation preceded caspase activation and followed AIF translocation from mitochondria to nucleus, which was indicative of caspase-independent apoptotic cell death. HL-60 cells treated with subtoxic concentration of the compound displayed morphological signs of granulocytic differentiation (nuclear indentations and presence of cytoplasmic primary granules), as well as an increased expression of differentiation markers CD11b and CD15. The cyclohexyl analogues of ethylenediamine dipropanoic acid were also toxic to peripheral blood mononuclear cells of both healthy controls and leukemic patients, the latter being more sensitive. Our data demonstrate that the toxicity of the investigated cyclohexyl compounds against leukemic cell lines is mediated by caspase-independent apoptosis associated with oxidative stress, mitochondrial dysfunction, and AIF translocation.

The protective ability of novel arylpiperazine-based dopaminergic ligands against nitric oxide (NO)-mediated neurotoxicity is investigated. The most potent neuroprotective arylpiperazine identified during the study was N-{4-[2-(4-phenyl-piperazin-1-yl)ethyl]-phenyl}picolinamide, which protected SH-SY5Y human neuron-like cells from the proapoptotic effect of NO donor sodium nitroprusside (SNP) by decreasing oxidative stress, mitochondrial membrane depolarization, caspase activation and subsequent phosphatydilserine externalization/DNA fragmentation. The protective effect was associated with the inhibition of proapoptotic (JNK, ERK, AMPK) and activation of antiapoptotic (Akt) signaling pathways, in the absence of interference with intracellular NO accumulation. The neuroprotective action of arylpiperazines was shown to be independent of dopamine receptor binding, as it was not affected by the high-affinity D₁/D₂ receptor blocker butaclamol. These results reported support the further study of arylpiperazines as potential neuroprotective agents., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The in vitro and in vivo anti-melanoma effect of antidiabetic drug metformin was investigated using B16 mouse melanoma cell line. Metformin caused a G(2)/M cell cycle arrest associated with apoptotic death of melanoma cells, as confirmed by the flow cytometric analysis of cell cycle/DNA fragmentation, phosphatidylserine exposure and caspase activation. Metformin-mediated apoptosis of melanoma cells was preceded by induction of oxidative stress and mitochondrial membrane depolarization, measured by flow cytometry in cells stained with appropriate fluorescent reporter dyes. The expression of tumor suppressor protein p53 was increased, while the mRNA levels of anti-apoptotic Bcl-2 were reduced by metformin, as revealed by cell-based ELISA and real-time RT-PCR, respectively. Treatment with metformin did not stimulate expression of the cycle blocker p21, indicating that p21 was dispensable for the observed cell cycle arrest. The activation of AMP-activated protein kinase (AMPK) was not required for the anti-melanoma action of metformin, as AMPK inhibitor compound C completely failed to restore viability of metformin-treated B16 cells. Metformin induced autophagy in B16 cells, as demonstrated by flow cytometry-detected increase in intracellular acidification and immunoblot-confirmed upregulation of autophagosome-associated LC3-II. Autophagy inhibitors ammonium chloride and wortmannin partly restored the viability of metformin-treated melanoma cells. Finally, oral administration of metformin led to a significant reduction in tumor size in a B16 mouse melanoma model. These data suggest that anti-melanoma effects of metformin are mediated through p21- and AMPK-independent cell cycle arrest, apoptosis and autophagy associated with p53/Bcl-2 modulation, mitochondrial damage and oxidative stress., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Metformin is an antidiabetic drug with anticancer properties, which mainly acts through induction of AMP-activated protein kinase (AMPK). In the present study we investigated the influence of metformin on the in vitro anticancer activity of the well-known chemotherapeutic agent cisplatin. Cell viability was determined by MTT and LDH release assay, oxidative stress and apoptosis (caspase activation, DNA fragmentation, and phosphatidylserine exposure) were assessed by flow cytometry, while activation of AMPK and Akt was analyzed by immunoblotting. Although metformin reduced the number of tumour cells when applied alone, it surprisingly antagonized the cytotoxicity of cisplatin towards U251 human glioma, C6 rat glioma, SHSY5Y human neuroblastoma, L929 mouse fibrosarcoma and HL-60 human leukemia cell lines. Only in B16 mouse melanoma cells metformin augmented the cytotoxicity of cisplatin. In U251 glioma cells metformin suppressed cisplatin-induced apoptotic cell death through inhibition of oxidative stress and caspase activation. The observed cytoprotection was apparently AMPK-independent, as metformin did not further increase cisplatin-induced AMPK activation in U251 cells and other pharmacological AMPK activators failed to block cisplatin-mediated apoptosis. On the other hand, metformin induced Akt activation in cisplatin-treated cells and Akt inhibitor 10-DEBC hydrochloride or phosphoinositide 3-kinase/Akt inhibitor LY294002 abolished metformin-mediated antioxidant and antiapoptotic effects. In conclusion, the antidiabetic drug metformin reduces cisplatin in vitro anticancer activity through AMPK-independent upregulation of Akt survival pathway. These data warrant caution when considering metformin for treatment of diabetic cancer patients receiving cisplatin or as a potential adjuvant in cisplatin-based chemotherapeutic regimens., (Copyright © 2010. Published by Elsevier B.V.)