MicroRNA-26a regulates glucose metabolism by direct targeting PDHX in colorectal cancer cells
© Chen et al.; licensee BioMed Central Ltd. 2014
Received: 16 April 2014
Accepted: 10 June 2014
Published: 16 June 2014
Reprogramming energy metabolism has been an emerging hallmark of cancer cells. MicroRNAs play important roles in glucose metabolism.
The targets of microRNA-26a (miR-26a) were predicted by bioinformatics tools. The efficacy of miR-26a binding the 3′-untranslated region (UTR) of pyruvate dehydrogenase protein X component (PDHX) mRNA was evaluated using a dual-luciferase reporter assay. The PDHX expression at the mRNA and protein level in several colon cancer cell lines was quantified with real-time PCR and Western blot analysis respectively. The effects of miR-26a on glucose metabolism were determined by detecting the content of glucose consumption, production of lactate, pyruvate, and acetyl-coenzyme A.
The expression of miR-26a is inversely associated with the level of its targeting protein PDHX in several colon cancer cell lines with different malignancy potentials. MiR-26a inhibits PDHX expression by direct targeting the 3′-UTR of PDHX mRNA. The glucose consumption and lactate concentration were both greatly increased in colon cancer cells than the normal colon mucosal epithelia under physiological conditions. The overexpression of miR-26a in HCT116 cells efficiently improved the accumulation of pyruvate and decreased the production of acetyl coenzyme A. Meanwhile the inhibition of miR-26a expression induced inverse biological effects.
MiR-26a regulates glucose metabolism of colorectal cancer cells by direct targeting the PDHX, which inhibits the conversion of pyruvate to acetyl coenzyme A in the citric acid cycle.
KeywordsMicroRNA-26a PDHX Colorectal cancer Glucose metabolism
Recent studies have shown that microRNAs (miRNAs) play important roles in energy metabolism , and thus in cancer cells the alterations of cellular metabolism are associated with miRNA dysregulation [2, 3]. MiRNAs participate in cell metabolism by regulating the expression of genes whose protein products either directly regulate metabolic machinery or indirectly modulate the expression of metabolic enzymes, serving as master regulators . For example, microRNA-195-5p  and microRNA-143  can repress the glucose uptake and glycolysis processing by inhibiting the expression of glucose transporter 3 (GLUT3) and hexokinase 2 respectively. And microRNA-143 could affect the glucose metabolism by regulating the AKT signaling pathway .
Reprogramming energy metabolism has been an emerging hallmark of cancer . The best characterized metabolic phenotype in cancer cells is the “Warburg effect”. Even in the presence of oxygen, cancer cells can reprogram their glucose metabolism, and thus the ATP generation shifts from oxidative phosphorylation to glycolysis, leading to a state termed “aerobic glycolysis” . Unlike normal cells, cancer cells usually derive a substantial amount of energy from aerobic glycolysis by converting most incoming glucose to lactate rather than metabolizing it through oxidative phosphorylation. Although ATP production via glycolysis can be more rapid than by oxidative phosphorylation, the ATP generated is far less for per unit of glucose consumed. As a result, this shift demands that cancer cells implement an abnormally high rate of glucose uptake to meet their increased energy and biosynthesis. By now, several studies have focused on miRNA contributions to the “Warburg effect” [1, 3], and many molecules regulated by miRNAs are investigated.
MicroRNA-26a (miR-26a) shows a higher expression level in colon cancer tissues than in normal colon tissues , and its expression is also elevated under hypoxia conditions . Meanwhile, miR-26a has been reported to play functions in cellular differentiation, cell growth, cell apoptosis and metastasis [12–15]. However, none of these studies on miRNA-26a focuses on energy metabolism. Several glycolysis genes, including glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase 1 and phosphoglycerate mutase 1, have up-regulation in colon cancer tissues , therefore colon cancer cells have a higher glycolytic rate compared with normal cells . In this study, we aim to discover the function of miR-26a on glucose metabolism in colorectal cancer cells. We have identified the pyruvate dehydrogenase protein X component (PDHX) as a direct target of miR-26a that is involved in the biological processes of glucose metabolism in colorectal cancer (CRC) cells.
The CRC cell lines including SW620, SW480 and HCT116 were ordered from American Type Culture Collection. The cell line NCM460, which is derived from normal human colon mucosal epithelium, was ordered from the INCELL Corporation, LLC, USA (http://www.incell.com). The cells were all cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum at 37°C in humidified atmosphere with 5% (v/v) CO2.
Prediction of candidate miRNA targets
The alignment of the miR-26a seed region and 3′-untranslated regions (UTR) of PDHX mRNA of different species were analyzed as literatures described previously [6, 18]. The possible targets of miR-26a were screened by bioinformatics tools, Pictar (http://pictar.mdc-berlin.de) and TargetScan (http://www.targetscan.org).
Construction of expression plasmids
A 461-bp nucleotide fragments in pre-miR-26a sequences (Additional file 1: Table S1) were cloned into the pENTR-CMV-EGFP vector (ordered from Wuhan Cell marker Biotechnology Co., Ltd., Wuhan, P. R. China) between XhoI and EcoRI to construct miR-26a expression plasmid, pENTR-miR-26a. The empty vector pENTR-MIRNA was used as a control in the ectopic overexpression of miR-26a.
Cells treated with MiR-26a inhibitor
The miR-26a inhibitor was commercially available chemically modified antisense oligonucleotide inhibitor (Product ID: MH10249, Cat. #4464084, Life Technologies Corporation, USA). The non-targeting oligonucleotides (Cat. #4464076, Life Technologies Corporation, USA), as a negative control, were also ordered from this company.
The miR-26a inhibitor or the negative control was respectively transfected at a working concentration of 30 nM using Lipofectamine 2000 reagent (Cat. #11668-019, Invitrogen). The ratio of Lipofectamine 2000 reagent (μL) versus the oligonucleotides (pmol) was 18:1.
RNA extraction and real-time PCR
Total RNA was extracted using Trizol reagent (Cat. #15596-026, Invitrogen). The total RNA was dissolved with RNase-free water for use. The first-strand cDNA for miR-26a was generated using a cDNA synthesis kit (Cat. #K1622, Thermo Scientific). Specific primers were designed for the reverse transcription of miR-26a and U6. The primer sequences for miR-26a were TGTCAACGATACGCTACCTAACGGCATGACAGTGTCAGCCTA. And the primer for U6 was GAACGCTTCACGAATTTGC based on literature reports . For PDHX, random primers were used for mRNA reverse transcription (Cat. #170-8890, Bio-Rad).
The real-time PCR was performed to measure the relative expression using the Supermix-Bio-Rad kit (Cat. #172-5261, Bio-Rad) following the protocol. The U6 was used as an internal reference to calculate the relative expression level of miRNA, and the GAPDH mRNA level was taken as a comparison base for the target RNA expression. The relative RNA expression was calculated with the comparative CT method, which was normalized to the internal references. The forward RT-PCR primer for PDHX was 5′-GTCCCTCTAAAGCAGCTCAAAA-3′, and the reverse one was 5′-CTCCCTTCAAAAGATCCAACTG-3′. The forward one for miR-26a was 5′-CTGTCAACGATACGCTAC-3′, and its reverse was 5′-GTAATCCAGGATAGGCTG-3′. In addition, the forward RT-PCR primer for U6 was 5′-CTTCGGCAGCACATATAC-3′, meanwhile its reverse primer was 5′-GAACGCTTCACGAATTTGC-3′.
The miR-26a expression plasmid pENTR-miR-26a or the empty vector pENTR-MIRNA was respectively transfected at a working concentration of 100 nM using Lipofectamine 2000 reagent (Cat. #11668-019, Invitrogen). The ratio of DNA (μg) versus the Lipofectamine 2000 reagent (μL) was 1: 2.
For the promoter luciferase reporter assay, the plasmid pwt-PDHX or pmt-PDHX was co-transfected with the miR-26a expression vector pENTR-miR-26a or the empty vector pENTR-MIRNA into HEK293T cells. As mentioned above, Lipofectamine 2000 was used as the transfection reagent. The plasmid was used at a working concentration of 100 nM as well. The ratio of plasmid DNA (μg) versus the Lipofectamine 2000 reagent (μL) was 1: 2.
Western blot analysis
The protein PDHX was detected against its specific antibody by western blot. The PVDF membranes were respectively incubated with the primary antibody of PDHX (diluted 1:1000, Cat. # S0394, Epitomics, USA) at 4°C overnight, followed by incubating with a secondary HRP-conjugated antibody at 37°C for 1 h. Signal detection was performed with Luminata Crescendo Western HRP Substrate (Cat. # WBLUR0100, Millipore). The detection of GAPDH using its antibody (Cat. # sc-365062, Santa Cruz Biotechnology) was taken as a control.
Luciferase reporter assay
Either the plasmid pwt-PDHX or pmt-PDHX was respectively co-transfected with the miR-26a expression vector pENTR-miR-26a into HEK293T cells, and cells were harvested for assessment of luciferase activity at 48 hours after transfection. The luciferase activities of cellular extracts were measured with a Dual Luciferase Reporter Assay System (Cat. #E1910, Promega). Both Renilla luciferase and firefly luciferase activities were measured. The luciferase signal was normalized to the firefly luciferase signal as described previously .
Measurement of glucose consumption and lactate production
Either the pENTR-miR-26a or miR-26a inhibitor was transfected into CRC cells. Cell culture media were collected after transfection for 48 h. Glucose uptake and lactate production were measured using Amplex® Red Glucose/Glucose Oxidase Assay Kit (Cat. #A22189; Invitrogen) and lactate assay kit (Cat. #MAK064; Sigma-Aldrich) respectively. The results were normalized on the basis of total cellular protein amounts.
The concentration of pyruvate in CRC cells, transfected with pENTR-miR-26a or miR-26a inhibitor, was respectively measured using pyruvate assay kit (Cat. #K609-100; BioVision). Briefly, cells were collected after transfection for 48 h and dissolved with 0.5 ml of pyruvate assay buffer. And 50 μl sample was added with 50 μl of reaction mixture to incubate at room temperature for 30 minutes. A standard curve covering a range of 10–0.1 nmol per well was used as control. Absorbance was measured at 570 nm. The pyruvate concentration, which was normalized on the basis of totally cellular protein amounts, was calculated relative to the standard curve.
To analyze the production of acetyl coenzyme A (acetyl-CoA), cell extracts were prepared using the perchloric acid approach as described previously, with minor modification . CRC cells, treated with pENTR-miR-26a or miR-26a inhibitor, were harvested and washed with phosphate-buffered saline. Cells were mixed in 1 mL of washing buffer (10 mM sodium phosphate [pH 7.5], 10 mM MgCl2, 1 mM EDTA), treated with 200 μL of 3 M ice-cold HClO4, and incubated on ice for 30 minutes. The mixture was centrifuged for 5 minutes at 10,000 × g at 4°C. The supernatant was neutralized with saturated KHCO3 and centrifuged as described above. The level of acetyl-CoA in the cell extraction was quantified using the acetyl-CoA assay kit (Cat. # K317-100; BioVision). Fluorescence was measured (Ex/Em = 535/589 nm), and the acetyl-CoA concentration was calculated based on the standard curve. The production of acetyl-CoA was normalized based on the total of cellular proteins.
Bioinformatics analysis for potential targets of miR-26a
MiR-26a level is inversely associated with the protein expression of PDHX
The expression level of miR-26a in NCM460, HCT116, SW480 and SW620 cells was examined using q-PCR analysis (Figure 2C). Compared with the normal epithelial cells NCM460, the expression of miR-26a was significantly increased to 1.3, 1.7 and 4.6-fold for the colon cancer cell lines HCT116, SW480 and SW620 respectively (p < 0.05). Generally, the expression level of miR-26a was significantly higher in malignant CRC cell lines HCT116, SW480 and SW620 than in a normal colorectal mucosal epithelial cell line NCM460 , especially it was almost increased over 4-fold in SW620 cells, which has high lymph node metastatic potentials . Among the three CRC cell lines, the expression levels of miR-26a were gradually increased from HCT116 to SW480 and SW620 cells. Compared with HCT116 cells, which is derived from a human colorectal adenocarcinoma , SW480 and SW620 cells are typical model systems for CRC metastasis. The SW480 is derived from the primary site of CRC and SW620 comes from the recurrent lymph node metastasis . Therefore, it has a positive correlation between the expression levels of miR-26a and the malignant degree of CRC cells.As miRNA expression is often inversely correlated with those of their specific target mRNAs, we further analyzed the protein expression of the miR-26a target —PDHX, in CRC cell lines. We found that the expression of PDHX was stepwise decreased in NCM460, HCT116, SW480 and SW620 cells (Figure 2D). The expression level of miR-26a in NCM460 was the lowest among the four cell lines (Figure 2C), but the protein level of PDHX exhibited the highest (Figure 2D). While in SW620 cells, the highest level of miR-26a expression and the lowest level of PDHX expression were observed. By comparing the expression levels of miR-26a and PDHX, an inverse correlation between them was observed in CRC cell lines, which supported the bioinformatics prediction on miR-26a target as above.
PDHX is a direct target of miR-26a
Except to the gain and loss-of function studies, the direct regulatory effect of miR-26a on PDHX expression was also verified by Renilla luciferase reporter gene assays. Either the plasmid pwt-PDHX or pmt-PDHX was co-transfected with the miR-26a-expressing pENTR-miR-26a into HEK293T cells respectively. Cells were harvested for assessment of luciferase activity at 48 hours after transfection. Compared with the mutated reporter plasmid pmt-PDHX, when the wild type plasmid pwt-PDHX was co-transfected with the miR-26a-expressing plasmid pENTR-miR-26a, the ectopically expressing miR-26a bound to the 3′ UTR of the wild type plasmid pwt PDHX, then the fused luciferase and the 3′UTR of PDHX was cleaved and subsequently degraded, which resulted in an effective decrease of luciferase activity (Figure 1B). By contrast, in the case of the co-transfection of the mutant plasmid pmt-PDHX with the pENTR-miR-26a, the ectopically expressing miR-26a couldn’t bind to the 3′ UTR of the mutant type plasmid pmt-PDHX, furthermore the luciferase activity did not be decreased. These data showed that miR-26a modulates the PDHX expression by direct targeting the 3′UTR mRNA of PDHX.
MiR-26a affects cell glucose metabolism
The role of miR-26a in carcinogenesis appears to be a complicated one, in the sense that both oncogenic and tumor suppressive effects were reported in cancers. For example, miR-26a enhances lung cancer cell metastasis potential via activating AKT pathway by phosphatase and tensin homolog (PTEN) suppression . Other studies find that miR-26a suppresses cell growth and metastasis through IL-6-Stat3 signaling in hepatocellular carcinoma . Our study showed that miR-26a has an increased level in CRC cells, especially it has much higher expression in high-metastasis SW620 cells (Figure 2C). The finding indicates miR-26a has an oncogenic role in the carcinogenesis of CRC.
More importantly, we also discovered the molecular mechanism of miR-26a involved in glucose metabolism of colon cancer cells. The miR-26a inhibits the expression of PDHX by direct targeting the conserved miR-26a recognition motif of the 3′UTR of PDHX mRNA, which efficiently decreases the process of pyruvate-acetyl-CoA conversion and thus blocks the key step of glycolysis to the citric acid cycle in glucose metabolism. The PDHX is a non-catalytic subunit of the PDH complex, which is located in the mitochondrial matrix and is central to mitochondrial fuel metabolism . The PDH complex catalyzes the irreversible oxidation of pyruvate to acetyl CoA, a rate-limiting step under aerobic conditions for the oxidative removal of glucose and pyruvate and for other 3-carbon metabolites (alanine and lactate) in equilibrium with pyruvate . Except to the non-catalytic subunit PDHX, the PDH complex contains three catalytic subunits (pyruvate dehydrogenase E1, dihydrolipoamide transacetylase E2 and dihydrolipoamide dehydrogenase E3) and two regulatory subunits (E1 kinase and E1 phosphatase). It is known that PDHX is required for tethering E3 dimers to the E2 core and this specific binding is essential for a functional PDH complex. Our results provided experimental evidences to verify the bioinformatics speculation that miR-26a has a high possibility to regulate PDHX in lung cancer . So far, it is the first report to explore the miR-26a-regulated glucose metabolism via targeting PDHX in CRC, which is helpful for understanding miRNA functions in the biochemical processes of the Warburg effect in tumors.
Glucose utilization was changed significantly in HCT116 cells when miR-26a was ectopically overexpressed or inhibited. It seems that miR-26a might prompt glucose uptake to meet the need of energy and biosynthesis in cancer cells. Most mammalian cells import glucose by a process of facilitative diffusion mediated by members of GLUTs family . The effects of miR-26a on the expression and/or the translocation of the GLUT proteins could be very interesting to further investigate in our following research. Furthermore, growing evidence has shown that cancer cell metabolism is also controlled by external responses to the tumour microenvironment . For example, cancer-associated fibroblasts have been reported to undergo Warburg metabolism and mitochondrial oxidative stress . They are possibly correlated with metabolic reprogramming of cancer cells toward Warburg metabolism by rapidly expressing carbonic anhydrase IX, which could result in extracellular acidification . These factors will be considered in our further study.
Recently, microRNA molecules are already entering the clinic as potential diagnostic and prognostic biomarkers, as well as therapeutic targets or agents . The miRNAs as important regulators of metabolism have garnered much interest not only from a scientific point of view but also from a clinical perspective . The function of miRNAs on cellular metabolism reveals molecular strategies for controlling metabolic flux by miRNAs in living organisms, thus lighting up one aspect of miRNA therapeutics. The use of miRNAs, such as oligonucleotide complementary  or antisense oligonucleotides  in miRNA inhibition, to suppress cell metabolism altering will hopefully lead to a new therapeutic strategy for malignant cancer [36, 37]. A high rate of glycolysis to obtain energy is a commonly observed feature in cancers, and previous studies usually focus on miRNA roles in targeting the key enzymes of glycolysis, including hexokinase-2 , and pyruvate dehydrogenase kinase [38, 39]. Our data indicated that miR-26a also regulates the process of pyruvate-acetyl-CoA conversion which is the former reaction of entering the citric acid cycle. Previous studies have shown that miR-26a is significantly associated with disease progression and therapy response in CRC [39–42]. Therefore, the miR-26a is a potential cancer therapeutic target by regulating glucose metabolism in CRC, which also provides a promising anti-neoplasia strategy.
The expression levels of miR-26a are associated with the malignant degrees of CRC cells. MiR-26a has key roles in regulating glucose metabolism by direct targeting PDHX in CRC cells , which inhibits the conversion of pyruvate to acetyl CoA in tricarboxylic acid cycle. These novel findings are helpful for understanding the CRC development and indicate a promising anti-neoplasia strategy.
Pyruvate dehydrogenase protein X component
acetyl coenzyme A.
This work was financially supported by the grants from National Key Basic Research Program of China (2011CB910703, 2013CB911303), the National 863 High Tech Foundation (2014AA020608), National Natural Sciences Foundation of China (30970654, 31071235), grants for New Century Excellent Talents in University (NCET-10-0595) and specialized research fund for the Doctoral Program of Higher Education (20120181110025). The authors gratefully acknowledged the support of Sichuan Province Program (2010JQ0016, 2012SZ0002).
- Chen B, Li H, Zeng X, Yang P, Liu X, Zhao X, Liang S: Roles of microRNA on cancer cell metabolism. J Transl Med. 2012, 10 (1): 228-10.1186/1479-5876-10-228.View ArticlePubMedPubMed CentralGoogle Scholar
- Pucci S, Mazzarelli P: MicroRNA dysregulation in colon cancer microenvironment interactions: the importance of small things in metastases. Cancer Microenviron. 2011, 4 (2): 155-162. 10.1007/s12307-011-0062-y.View ArticlePubMedPubMed CentralGoogle Scholar
- Fang R, Xiao T, Fang Z, Sun Y, Li F, Gao Y, Feng Y, Li L, Wang Y, Liu X, Chen H, Liu X, Ji H: MicroRNA-143 (miR-143) regulates cancer glycolysis via targeting hexokinase 2 gene. J Biol Chem. 2012, 287 (27): 23227-23235. 10.1074/jbc.M112.373084.View ArticlePubMedPubMed CentralGoogle Scholar
- Singh PK, Brand RE, Mehla K: MicroRNAs in pancreatic cancer metabolism. Nat Rev Gastroenterol Hepatol. 2012, 9 (6): 334-344. 10.1038/nrgastro.2012.63.View ArticlePubMedPubMed CentralGoogle Scholar
- Fei X, Qi M, Wu B, Song Y, Wang Y, Li T: MicroRNA-195-5p suppresses glucose uptake and proliferation of human bladder cancer T24 cells by regulating GLUT3 expression. FEBS Lett. 2012, 586 (4): 392-397. 10.1016/j.febslet.2012.01.006.View ArticlePubMedGoogle Scholar
- Peschiaroli A, Giacobbe A, Formosa A, Markert EK, Bongiorno-Borbone L, Levine AJ, Candi E, D’Alessandro A, Zolla L, Finazzi Agro A, Melino G: miR-143 regulates hexokinase 2 expression in cancer cells. Oncogene. 2013, 32 (6): 797-802. 10.1038/onc.2012.100.View ArticlePubMedGoogle Scholar
- Jordan SD, Krüger M, Willmes DM, Redemann N, Wunderlich FT, Brönneke HS, Merkwirth C, Kashkar H, Olkkonen VM, Böttger T, Braun T, Seibler J, Brüning JC: Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism. Nat Cell Biol. 2011, 13 (4): 434-446. 10.1038/ncb2211.View ArticlePubMedGoogle Scholar
- Hanahan D, Weinberg RA: Hallmarks of cancer: the next generation. Cell. 2011, 144 (5): 646-674. 10.1016/j.cell.2011.02.013.View ArticlePubMedGoogle Scholar
- Cairns RA, Harris IS, Mak TW: Regulation of cancer cell metabolism. Nat Rev Cancer. 2011, 11 (2): 85-95. 10.1038/nrc2981.View ArticlePubMedGoogle Scholar
- Volinia S, Calin GA, Liu CG, Ambs S, Cimmino A, Petrocca F, Visone R, Iorio M, Roldo C, Ferracin M, Prueitt RL, Yanaihara N, Lanza G, Scarpa A, Vecchione A, Negrini M, Harris CC, Croce CM: A microRNA expression signature of human solid tumors defines cancer gene targets. Proc Natl Acad Sci U S A. 2006, 103 (7): 2257-2261. 10.1073/pnas.0510565103.View ArticlePubMedPubMed CentralGoogle Scholar
- Kulshreshtha R, Ferracin M, Wojcik SE, Garzon R, Alder H, Agosto-Perez FJ, Davuluri R, Liu CG, Croce CM, Negrini M, Calin GA, Ivan M: A microRNA signature of hypoxia. Mol Cell Biol. 2007, 27 (5): 1859-1867. 10.1128/MCB.01395-06.View ArticlePubMedPubMed CentralGoogle Scholar
- Zhang B, Liu XX, He JR, Zhou CX, Guo M, He M, Li MF, Chen GQ, Zhao Q: Pathologically decreased miR-26a antagonizes apoptosis and facilitates carcinogenesis by targeting MTDH and EZH2 in breast cancer. Carcinogenesis. 2011, 32 (1): 2-9. 10.1093/carcin/bgq209.View ArticlePubMedGoogle Scholar
- Chen L, Zheng J, Zhang Y, Yang L, Wang J, Ni J, Cui D, Yu C, Cai Z: Tumor-specific expression of microRNA-26a suppresses human hepatocellular carcinoma growth via cyclin-dependent and -independent pathways. Mol Ther. 2011, 19 (8): 1521-1528. 10.1038/mt.2011.64.View ArticlePubMedPubMed CentralGoogle Scholar
- Leeper NJ, Raiesdana A, Kojima Y, Chun HJ, Azuma J, Maegdefessel L, Kundu RK, Quertermous T, Tsao PS, Spin JM: MicroRNA-26a is a novel regulator of vascular smooth muscle cell function. J Cell Physiol. 2011, 226 (4): 1035-1043. 10.1002/jcp.22422.View ArticlePubMedPubMed CentralGoogle Scholar
- Liu B, Wu X, Wang C, Liu Y, Zhou Q, Xu K: MiR-26a enhances metastasis potential of lung cancer cells via AKT pathway by targeting PTEN. Biochim Biophys Acta. 2012, 1822 (11): 1692-1704. 10.1016/j.bbadis.2012.07.019.View ArticlePubMedGoogle Scholar
- Altenberg B, Greulich KO: Genes of glycolysis are ubiquitously overexpressed in 24 cancer classes. Genomics. 2004, 84 (6): 1014-1020. 10.1016/j.ygeno.2004.08.010.View ArticlePubMedGoogle Scholar
- Alcarraz-Vizan G, Sanchez-Tena S, Moyer MP, Cascante M: Validation of NCM460 cell model as control in antitumor strategies targeting colon adenocarcinoma metabolic reprogramming: Trichostatin A as a case study. Biochim Biophys Acta. 2013, 1840 (6): 1634-1639.View ArticlePubMedGoogle Scholar
- Krek A, Grun D, Poy MN, Wolf R, Rosenberg L, Epstein EJ, MacMenamin P, da Piedade I, Gunsalus KC, Stoffel M, Rajewsky N: Combinatorial microRNA target predictions. Nat Genet. 2005, 37 (5): 495-500. 10.1038/ng1536.View ArticlePubMedGoogle Scholar
- Jiang S, Zhang LF, Zhang HW, Hu S, Lu MH, Liang S, Li B, Li Y, Li D, Wang ED, Liu MF: A novel miR-155/miR-143 cascade controls glycolysis by regulating hexokinase 2 in breast cancer cells. EMBO J. 2012, 31 (8): 1985-1998. 10.1038/emboj.2012.45.View ArticlePubMedPubMed CentralGoogle Scholar
- Sze CW, Li C: Inactivation of bb0184, which encodes carbon storage regulator A, represses the infectivity of Borrelia burgdorferi. Infect Immun. 2011, 79 (3): 1270-1279. 10.1128/IAI.00871-10.View ArticlePubMedGoogle Scholar
- Moyer MP, Manzano LA, Merriman RL, Stauffer JS, Tanzer LR: NCM460, a normal human colon mucosal epithelial cell line. In Vitro Cell Dev Biol Anim. 1996, 32 (6): 315-317. 10.1007/BF02722955.View ArticlePubMedGoogle Scholar
- Bhattacharyya NP, Skandalis A, Ganesh A, Groden J, Meuth M: Mutator phenotypes in human colorectal carcinoma cell lines. Proc Natl Acad Sci U S A. 1994, 91 (14): 6319-6323. 10.1073/pnas.91.14.6319.View ArticlePubMedPubMed CentralGoogle Scholar
- Xue H, Lü B, Zhang J, Wu M, Huang Q, Wu Q, Sheng H, Wu D, Hu J, Lai M: Identification of serum biomarkers for colorectal cancer metastasis using a differential secretome approach. J Proteome Res. 2009, 9 (1): 545-555.View ArticleGoogle Scholar
- Tajir M, Arnoux JB, Boutron A, Elalaoui SC, De Lonlay P, Sefiani A, Brivet M: Pyruvate dehydrogenase deficiency caused by a new mutation of PDHX gene in two Moroccan patients. Eur J Med Genet. 2012, 55 (10): 535-540. 10.1016/j.ejmg.2012.06.006.View ArticlePubMedGoogle Scholar
- Mine M, Brivet M, Schiff M, de Baulny HO, Chuzhanova N, Marsac C: A novel gross deletion caused by non-homologous recombination of the PDHX gene in a patient with pyruvate dehydrogenase deficiency. Mol Genet Metab. 2006, 89 (1–2): 106-110.View ArticlePubMedGoogle Scholar
- Huse JT, Brennan C, Hambardzumyan D, Wee B, Pena J, Rouhanifard SH, Sohn-Lee C, le Sage C, Agami R, Tuschl T, Holland EC: The PTEN-regulating microRNA miR-26a is amplified in high-grade glioma and facilitates gliomagenesis in vivo. Genes Dev. 2009, 23 (11): 1327-1337. 10.1101/gad.1777409.View ArticlePubMedPubMed CentralGoogle Scholar
- Yang X, Liang L, Zhang XF, Jia HL, Qin Y, Zhu XC, Gao XM, Qiao P, Zheng Y, Sheng YY, Wei JW, Zhou HJ, Ren N, Ye QH, Dong QZ, Qin LX: MicroRNA-26a suppresses tumor growth and metastasis of human hepatocellular carcinoma by targeting interleukin-6-Stat3 pathway. Hepatology. 2013, 58 (1): 158-170. 10.1002/hep.26305.View ArticlePubMedGoogle Scholar
- Stacpoole PW: The pyruvate dehydrogenase complex as a therapeutic target for age‒related diseases. Aging Cell. 2012, 11: 371-377. 10.1111/j.1474-9726.2012.00805.x.View ArticlePubMedGoogle Scholar
- Margineantu DH, Brown RM, Brown GK, Marcus AH, Capaldi RA: Heterogeneous distribution of pyruvate dehydrogenase in the matrix of mitochondria. Mitochondrion. 2002, 1 (4): 327-338. 10.1016/S1567-7249(01)00033-2.View ArticlePubMedGoogle Scholar
- Thorens B, Mueckler M: Glucose transporters in the 21st century. Am J Physiol Endocrinol Metab. 2010, 298: E141-E145. 10.1152/ajpendo.00712.2009.View ArticlePubMedGoogle Scholar
- Fiaschi T, Marini A, Giannoni E, Taddei M, Gandellini P, De Donatis A, Lanciotti M, Serni S, Cirri P, Chiarugi P: Reciprocal metabolic reprogramming through lactate shuttle coordinately influences tumor-stroma interplay. Cancer Res. 2012, 72: 5130-5140. 10.1158/0008-5472.CAN-12-1949.View ArticlePubMedGoogle Scholar
- Fiaschi T, Giannoni E, Taddei M, Cirri P, Marini A, Pintus G, Nativi C, Richichi B, Scozzafava A, Carta F, Torre E, Supuran CT, Chiarugi P: Carbonic anhydrase IX from cancer-associated fibroblasts drives epithelial-mesenchymal transition in prostate carcinoma cells. Cell Cycle. 2013, 12: 1791-1801. 10.4161/cc.24902.View ArticlePubMedPubMed CentralGoogle Scholar
- Jansson MD, Lund AH: MicroRNA and cancer. Mol Oncol. 2012, 6 (6): 590-610. 10.1016/j.molonc.2012.09.006.View ArticlePubMedGoogle Scholar
- Lanford RE, Hildebrandt-Eriksen ES, Petri A, Persson R, Lindow M, Munk ME, Kauppinen S, Orum H: Therapeutic silencing of microRNA-122 in primates with chronic hepatitis C virus infection. Science. 2010, 327 (5962): 198-201. 10.1126/science.1178178.View ArticlePubMedGoogle Scholar
- Stenvang J, Petri A, Lindow M, Obad S, Kauppinen S: Inhibition of microRNA function by antimiR oligonucleotides. Silence. 2012, 3 (1): 1-10.1186/1758-907X-3-1.View ArticlePubMedPubMed CentralGoogle Scholar
- Rossi JJ: New hope for a microRNA therapy for liver cancer. Cell. 2009, 137 (6): 990-992. 10.1016/j.cell.2009.05.038.View ArticlePubMedGoogle Scholar
- Pereira DM, Rodrigues PM, Borralho PM, Rodrigues CM: Delivering the promise of miRNA cancer therapeutics. Drug Discov Today. 2013, 18 (5–6): 282-289.View ArticlePubMedGoogle Scholar
- El Ouaamari A, Baroukh N, Martens GA, Lebrun P, Pipeleers D, van Obberghen E: miR-375 targets 3′-phosphoinositide-dependent protein kinase-1 and regulates glucose-induced biological responses in pancreatic beta-cells. Diabetes. 2008, 57 (10): 2708-2717. 10.2337/db07-1614.View ArticlePubMedPubMed CentralGoogle Scholar
- Kluza J, Corazao-Rozas P, Touil Y, Jendoubi M, Maire C, Guerreschi P, Jonneaux A, Ballot C, Balayssac S, Valable S, Corroyer-Dulmont A, Bernaudin M, Malet-Martino M, de Lassalle EM, Maboudou P, Formstecher P, Polakowska R, Mortier L, Marchetti P: Inactivation of the HIF-1alpha/PDK3 signaling axis drives melanoma toward mitochondrial oxidative metabolism and potentiates the therapeutic activity of pro-oxidants. Cancer Res. 2012, 72 (19): 5035-5047. 10.1158/0008-5472.CAN-12-0979.View ArticlePubMedGoogle Scholar
- Iorio MV, Croce CM: MicroRNA dysregulation in cancer: diagnostics, monitoring and therapeutics. A comprehensive review. EMBO Mol Med. 2012, 4 (3): 143-159. 10.1002/emmm.201100209.View ArticlePubMedPubMed CentralGoogle Scholar
- Boni V, Zarate R, Villa JC, Bandres E, Gomez MA, Maiello E, Garcia-Foncillas J, Aranda E: Role of primary miRNA polymorphic variants in metastatic colon cancer patients treated with 5-fluorouracil and irinotecan. Pharmacogenomics J. 2011, 11 (6): 429-436. 10.1038/tpj.2010.58.View ArticlePubMedGoogle Scholar
- Di Leva G, Briskin D, Croce CM: MicroRNA in cancer: new hopes for antineoplastic chemotherapy. Ups J Med Sci. 2012, 117 (2): 202-216. 10.3109/03009734.2012.660551.View ArticlePubMedPubMed CentralGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2407/14/443/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.