Lactate-Modulated Induction of THBS-1 Activates Transforming Growth Factor (TGF)-beta2 and Migration of Glioma Cells In Vitro

Background

An important phenomenon observed in glioma metabolism is increased aerobic glycolysis in tumor cells, which is generally referred to as the Warburg effect. Transforming growth factor (TGF)-beta2, which we previously showed to be induced by lactic acid, is a key pathophysiological factor in glioblastoma, leading to increased invasion and severe local immunosuppression after proteolytic cleavage from its latency associated peptide. In this study we tested the hypothesis, that lactate regulates TGF-beta2 expression and glioma cell migration via induction of Thrombospondin-1 (THBS-1), a TGF-beta activating protein.

Methods

Lactate levels were reduced by knockdown of LDH-A using specific small interfering RNA (siRNA) and competitive inhibition of LDH-A by sodium oxamate. Knockdown of THBS-1 was performed using specific siRNA. Western Blot, qRT-PCR, and ELISA were used to investigate expression levels of LDH-A, LDH-B, TGF-beta2 and THBS-1. Migration of cells was examined by Spheroid, Scratch and Boyden Chamber assays.

Results

Knockdown of LDH-A with subsequent decrease of lactate concentration leads to reduced levels of THBS-1 and TGF-beta2 in glioma cells. Lactate addition increases THBS-1 protein, leading to increased activation of TGF-beta2. Inhibition of THBS-1 reduces TGF-beta2 protein and migration of glioma cells. Addition of synthetic THBS-1 can rescue reduced TGF-beta2 protein levels and glioma cell migration in siLDH-A treated cells.

Conclusion

We define a regulatory cascade between lactate, THBS-1 and TGF-beta2, leading to enhanced migration of glioma cells. Our results demonstrate a specific interaction between tumor metabolism and migration and provide a better understanding of the mechanisms underlying glioma cell invasion.     

New Aspects of an Old Drug – Diclofenac Targets MYC and Glucose Metabolism in Tumor Cells

Non-steroidal anti-inflammatory drugs such as diclofenac exhibit potent anticancer effects. Up to now these effects were mainly attributed to its classical role as COX-inhibitor. Here we show novel COX-independent effects of diclofenac. Diclofenac significantly diminished MYC expression and modulated glucose metabolism resulting in impaired melanoma, leukemia, and carcinoma cell line proliferation in vitro and reduced melanoma growth in vivo. In contrast, the non-selective COX inhibitor aspirin and the COX-2 specific inhibitor NS-398 had no effect on MYC expression and glucose metabolism. Diclofenac significantly decreased glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), and monocarboxylate transporter 1 (MCT1) gene expression in line with a decrease in glucose uptake and lactate secretion. A significant intracellular accumulation of lactate by diclofenac preceded the observed effect on gene expression, suggesting a direct inhibitory effect of diclofenac on lactate efflux. While intracellular lactate accumulation impairs cellular proliferation and gene expression, it does not inhibit MYC expression as evidenced by the lack of MYC regulation by the MCT inhibitor α-cyano-4-hydroxycinnamic acid. Finally, in a cell line with a tetracycline-regulated c-MYC gene, diclofenac decreased proliferation both in the presence and absence of c-MYC. Thus, diclofenac targets tumor cell proliferation via two mechanisms, that is inhibition of MYC and lactate transport. Based on these results, diclofenac holds potential as a clinically applicable MYC and glycolysis inhibitor supporting established tumor therapies.     

Bioactivity-Guided Identification and Cell Signaling Technology to Delineate the Lactate Dehydrogenase A Inhibition Effects of Spatholobus suberectus on Breast Cancer

Aerobic glycolysis is an important feature of cancer cells. In recent years, lactate dehydrogenase A (LDH-A) is emerging as a novel therapeutic target for cancer treatment. Seeking LDH-A inhibitors from natural resources has been paid much attention for drug discovery. Spatholobus suberectus (SS) is a common herbal medicine used in China for treating blood-stasis related diseases such as cancer. This study aims to explore the potential medicinal application of SS for LDH-A inhibition on breast cancer and to determine its bioactive compounds. We found that SS manifested apoptosis-inducing, cell cycle arresting and anti-LDH-A activities in both estrogen-dependent human MCF-7 cells and estrogen-independent MDA-MB-231 cell. Oral herbal extracts (1 g/kg/d) administration attenuated tumor growth and LDH-A expression in both breast cancer xenografts. Bioactivity-guided fractionation finally identified epigallocatechin as a key compound in SS inhibiting LDH-A activity. Further studies revealed that LDH-A plays a critical role in mediating the apoptosis-induction effects of epigallocatechin. The inhibited LDH-A activities by epigallocatechin is attributed to disassociation of Hsp90 from HIF-1α and subsequent accelerated HIF-1α proteasome degradation. In vivo study also demonstrated that epigallocatechin could significantly inhibit breast cancer growth, HIF-1α/LDH-A expression and trigger apoptosis without bringing toxic effects. The preclinical study thus suggests that the potential medicinal application of SS for inhibiting cancer LDH-A activity and the possibility to consider epigallocatechin as a lead compound to develop LDH-A inhibitors. Future studies of SS for chemoprevention or chemosensitization against breast cancer are thus warranted.     

Metabolic activation triggered by cAMP in MCF-7 cells generates lethal vulnerability to combined oxamate/etomoxir

BackgroundAltered energy metabolism is a biochemical fingerprint of cancer cells, widely recognized as one of the “hallmarks of cancer”. Cancer cells show highly increased rates of glucose uptake and glycolysis, after which the resulting pyruvate is converted to lactate. The maintenance of this metabolic asset is warranted by lactate dehydrogenase A (LDH-A) and for this reason the development of novel LDH-targeted anticancer therapeutics is underway. However, possible interference in cancer cell metabolism could also arise from cAMP signaling pathway, which could be activated by either oncogenic induction or exogenously, as a result of microenvironment-derived stimuli, increasing cellular cAMP levels. This study aimed at evaluating the impact of activated cAMP signaling pathway on the efficacy of an LDH-targeted anticancer approach.MethodsWe exogenously activated cAMP signaling in MCF-7 human breast cancer cells and explored the metabolic interplay between LDH-A and cAMP pathway.ResultsIn cAMP-activated cells, we evidenced changes in energy metabolism which reduced their response to LDH inhibition. Interestingly, these experiments also highlighted a potential vulnerability state of treated cells.ConclusionscAMP-induced metabolic changes made MCF-7 cells a preferential target of a drug combination treatment which should not affect normal cell viability.General significancecAMP is a well-recognized second messenger of the pro-inflammatory cascade. The obtained results are relevant in consideration of the crucial role played by inflammation in normal breast cell transformation and in cancer progression. Furthermore, they corroborate the idea of exploiting the metabolic changes observed in cancer cells to obtain a therapeutic advantage.     

ANXA2P2/miR-9/LDHA axis regulates Warburg effect and affects glioblastoma proliferation and apoptosis

BackgroundAerobic glycolysis is a unique tumor cell phenotype considered as one of the hallmarks of cancer. Aerobic glycolysis can accelerate tumor development by increasing glucose uptake and lactate production. In the present study, lactate dehydrogenase A (LDHA) is significantly increased within glioma tissue samples and cells, further confirming the oncogenic role of LDHA within glioma.MethodsHematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were applied for histopathological examination. The protein levels of LDHA, transporter isoform 1 (GLUT1), hexokinase 2 (HK2), phosphofructokinase (PFK) in target cells were detected by Immunoblotting. The predicted miR-9 binding to lncRNA Annexin A2 Pseudogene 2 (ANXA2P2) or the 3′ untranslated region (UTR) of LDHA was verified using Luciferase reporter assay. Cell viability or apoptosis were examined by MTT assay or Flow cytometry. Intracellular glucose and Lactate levels were measured using glucose assay kit and lactate colorimetric assay kit.ResultsThe expression of ANXA2P2 showed to be dramatically upregulated within glioma tissue samples and cells. Knocking down ANXA2P2 within glioma cells significantly inhibited cell proliferation and aerobic glycolysis, as manifested as decreased lactate and increased glucose in culture medium, and downregulated protein levels of glycolysis markers, GLUT1, HK2, PFK, as well as LDHA. miR-9 was predicted to target both lncRNA ANXA2P2 and LDHA. The overexpression of miR-9 suppressed the cell proliferation and aerobic glycolysis of glioma cells. Notably, miR-9 could directly bind to LDHA 3′UTR to inhibit LDHA expression and decrease the protein levels of LDHA. ANXA2P2 competitively targeted miR-9, therefore counteracting miR-9-mediated repression on LDHA. Within tissues, miR-9 exhibited a negative correlation with ANXA2P2 and LDHA, respectively, whereas ANXA2P2 and LDHA exhibited a positive correlation with each other.ConclusionsIn conclusion, ANXA2P2/miR-9/LDHA axis modulates the aerobic glycolysis progression in glioma cells, therefore affecting glioma cell proliferation.     

Oxamate Improves Glycemic Control and Insulin Sensitivity via Inhibition of Tissue Lactate Production in db/db Mice

Oxamate (OXA) is a pyruvate analogue that directly inhibits the lactate dehydrogenase (LDH)-catalyzed conversion process of pyruvate into lactate. Earlier and recent studies have shown elevated blood lactate levels among insulin-resistant and type 2 diabetes subjects and that blood lactate levels independently predicted the development of incident diabetes. To explore the potential of OXA in the treatment of diabetes, db/db mice were treated with OXA in vivo. Treatment of OXA (350–750 mg/kg of body weight) for 12 weeks was shown to decrease body weight gain and blood glucose and HbA1c levels and improve insulin secretion, the morphology of pancreatic islets, and insulin sensitivity in db/db mice. Meanwhile, OXA reduced the lactate production of adipose tissue and skeletal muscle and serum lactate levels and decreased serum levels of TG, FFA, CRP, IL-6, and TNF-α in db/db mice. The PCR array showed that OXA downregulated the expression of Tnf, Il6, leptin, Cxcr3, Map2k1, and Ikbkb, and upregulated the expression of Irs2, Nfkbia, and Pde3b in the skeletal muscle of db/db mice. Interestingly, LDH-A expression increased in the islet cells of db/db mice, and both treatment of OXA and pioglitazone decreased LDH-A expression, which might be related to the improvement of insulin secretion. Taken together, increased lactate production of adipose tissue and skeletal muscle may be at least partially responsible for insulin resistance and diabetes in db/db mice. OXA improved glycemic control and insulin sensitivity in db/db mice primarily via inhibition of tissue lactate production. Oxamic acid derivatives may be a potential drug for the treatment of type 2 diabetes.     

LncRNA MYU对胶质瘤细胞周期分布、增殖、转移和凋亡以及PI3K/Akt信号通路的影响

摘要 目的：探讨长链非编码RNA（LncRNA）MYU对胶质瘤细胞周期分布、细胞增殖、迁移、侵袭和凋亡的影响,并初步探讨其作用机制。方法：实时荧光定量PCR（RT-qPCR）检测人脑正常胶质细胞HEB和胶质瘤细胞（U-251MG、A172、SHG139）中LncRNA MYU的表达情况。选取SHG139细胞,分为正常对照（NC）组、si-con组、si-LncRNA MYU组进行转染实验,行RT-qPCR检测转染效果。分别采用流式细胞术、细胞计数试剂盒（CCK-8）、Transwell实验检测沉默LncRNA MYU对SHG139细胞周期分布和凋亡、细胞增殖、细胞迁移和侵袭的影响。蛋白免疫印迹（Western blot）法检测基质金属蛋白酶2（MMP-2）、MMP-9、裂解的半胱氨酸天冬氨酸蛋白酶3（Cleaved caspase-3）、Cleaved caspase-9以及磷脂酰肌醇-3-羟激酶/蛋白激酶B（PI3K/Akt）信号通路相关蛋白表达情况。结果：LncRNA MYU在胶质瘤细胞株中比人脑正常胶质细胞中的表达水平显著升高（P＜0.05）,因此选择表达量最高的SHG139细胞进行转染实验。沉默LncRNA MYU能够显著诱导SHG139细胞G0-G1期阻滞、抑制细胞增殖、迁移和侵袭并诱导细胞凋亡（P＜0.05）。沉默LncRNA MYU可显著抑制MMP-2、MMP-9、p-PI3K和p-AKT表达并促进Cleaved caspase-3、Cleaved caspase-9表达（P＜0.05）。结论：沉默LncRNA MYU可诱导胶质瘤细胞G0-G1期阻滞,抑制细胞增殖、迁移和侵袭,促进细胞凋亡,其机制可能与抑制PI3K/AKT信号通路有关。     

A specific inhibitor of lactate dehydrogenase overcame the resistance toward gemcitabine in hypoxic mesothelioma cells,and modulated the expression of the human equilibrative transporter-1

ABSTRACT

Malignant pleural mesothelioma (MPM) is a very hypoxic malignancy, and hypoxia has been associated with resistance towards gemcitabine. The muscle-isoform of lactate dehydrogenase (LDH-A) constitutes a major checkpoint for the switch to anaerobic glycolysis. Therefore we investigated the combination of a new LDH-A inhibitor (NHI-1) with gemcitabine in MPM cell lines. Under hypoxia (O₂ tension of 1%) the cell growth inhibitory effects of gemcitabine, were reduced, as demonstrated by a 5- to 10-fold increase in IC₅₀s. However, the simultaneous addition of NHI-1 was synergistic (combination index < 1). Flow cytometry demonstrated that hypoxia caused a G1 arrest, whereas the combination of NHI-1 significantly increased gemcitabine-induced cell death. Finally, the mRNA expression levels of the human equilibrative transporter-1 (hENT1) were significantly down-regulated under hypoxia, but treatment with NHI-1 was associated with a recovery of hENT1 expression. In conclusion, our data show that hypoxia increased MPM resistance to gemcitabine. However, cell death induction and modulation of the key transporter in gemcitabine uptake may contribute to the synergistic interaction of gemcitabine with the LDH-A inhibitor NHI-1 and support further studies for the rational development of this combination.     

TCTP在辐射诱导胶质瘤细胞旁效应中的作用及机制研究

目的:研究肿瘤翻译控制蛋白(TCTP)在辐射诱导胶质瘤细胞旁效应中的作用及机制。方法:给予不同剂量的X射线照射U87、SHG44两种胶质瘤细胞,观察U87以及SHG44细胞的克隆形成率,并在给予最佳照射剂量后,通过Western Blot检测TCTP蛋白表达水平。将经过最佳X射线照射剂量的U87以及SHG44两种胶质瘤细胞与未经过辐射照射的细胞放在一起共培养,通过MTT实验检测胶质瘤细胞的增殖率,Western Blot检测共培养的胶质瘤细胞与经过辐射的胶质瘤细胞中Caspase3蛋白表达水平。结果:U87以及SHG44两种胶质瘤细胞的克隆形成率随着X射线照射剂量增加而显著性降低(P0.05),给予最佳X射线照射剂量后,与未经过X射辐射照射后的细胞相比,其TCTP蛋白表达水平明显升高(P0.05)。经过辐射照射与未经过辐射照射的胶质瘤细胞经过共培养后,与经过辐射的胶质瘤细胞相比,细胞的增殖率明显升高,同时共培养的胶质瘤细胞与经过辐射的胶质瘤细胞相比,Caspase3的蛋白表达明显降低(P0.05)。结论:TCTP的表达增高能够诱导未经过辐射的U87以及SHG44两种胶质瘤细胞的抗凋亡作用增强,其作用机制可能与Caspase3的表达降低有关。     

Proteomic analysis in NSAIDs-treated primary cardiomyocytes

NSAIDs (non-steroidal anti-inflammatory drugs) are widely used for the treatment of a variety of inflammatory diseases, but many of them were withdrawn from the market due to their cardiovascular toxicity. In this study, we tried to identify proteins responding to the cellular toxicity in NSAIDs-treated primarily cultured cardiomyocytes using 2-D proteomic analysis. We used seven different NSAIDs (celecoxib, rofecoxib, valdecoxib, diclofenac, naproxen, ibuprofen, and meloxicam) possessing each different degree of cardiovascular risk. Overall protein spots were similar in all NSAIDs-treated cells although numbers of decreased proteins were about 2-fold higher in celecoxib or rofecoxib-treated cells than in cells incubated with other NSAIDs. Many stress-related proteins, cardiac muscle movement proteins and proteins involved in membrane organization have been isolated. Among them, Septin-8, a filament scaffolding protein, showed its specific expression pattern depending on the extent of drug toxicity. Its expression level was low in cells treated by relatively high toxic drugs such as celecoxib, diclofenac, valdecoxib, and rofecoxib. On the contrary, Septin-8 was similarly expressed in control cells in the presence of less toxic drugs such ibuprofen, naproxen, and meloxicam. This data suggests that Septin-8 differentially responds to each NSAID.     

Cyclooxygenase inhibitors induce apoptosis in oral cavity cancer cells by increased expression of nonsteroidal anti-inflammatory drug-activated gene

We have investigated whether NAG-1 is induced in oral cavity cancer cells by various NSAIDs and if apoptosis induced by NSAIDs can be linked directly with the induction of NAG-1. NAG-1 expression was increased by diclofenac, aceclofenac, indomethacin, ibuprofen, and sulindac sulfide, in the order of NAG-1 induction, but not by acetaminophen, piroxicam or NS-398. Diclofenac was the most effective NAG-1 inducer. Incubation with diclofenac inhibited cell proliferation and induced apoptosis. The expression of NAG-1 was observed in advance of the induction of apoptosis. Conditioned medium from NAG-1-overexpressing Drosophila cells inhibited SCC 1483 cells proliferation and induced apoptosis. In summary, some NSAIDs induce NAG-1 expression in oral cavity cancer cells and the induced NAG-1 protein appears to mediate apoptosis. Therefore, NSAIDs may be considered as a possible chemopreventive agent against oral cavity cancer.     

FtMt promotes glioma tumorigenesis and angiogenesis via lncRNA SNHG1/miR-9-5p axis

ObjectiveThis study is to investigate the effects and the mechanisms of mitochondrial ferritin (FtMt) on the glioma tumorigenesis and angiogenesis.MethodsFtMt expression was detected in glioma tissues and cells as well as in nude mouse tissues. Cell proliferation and apoptosis rate were observed following transfection of LV-FtMt or sh-FtMt in glioma cell line. Moreover, glioma cells with FtMt over-expression/knockdown were co-cultured with human umbilical vein endothelial cells (HUVECs) to observe its function on HUVEC proliferation, angiogenic ability and the vascular endothelial growth factor (VEGF) content. Gain and loss of function of small nucleolar RNA host gene 1 (SNHG1) and miR-9-5p were performed in glioma cells and GBM nude mice to observe its effect on glioma cell proliferation and HUVEC angiogenic ability. Luciferase reporter gene and RIP assay were employed to inspect the interactions among SNHG1, FtMt and miR-9-5p. Additionally, a xenograft mouse model was applied to determine the role of FtMt in glioma.ResultsIn this work, FtMt was strongly expressed in glioma tissues and cells as well as in nude mouse tumor tissues. The employment of the loss-of and gain-of functions assays illustrated that FtMt enhanced glioma tumorigenesis and angiogenesis. Mechanistically, our findings showed that FtMt positively related to SNHG1 while negatively correlated with miR-9-5p, and both SNHG1 and FtMt can competitively bind with miR-9-5p. Besides, the inhibition effects of sh-FtMt on glioma were surveyed in vivo experiments.ConclusionEvidence in this study suggested that FtMt promotes glioma tumorigenesis and angiogenesis via SNHG1 mediated miR-9-5p expression, which may provide a theoretical basis for glioma treatment.     

Tyrosine phosphorylation of lactate dehydrogenase A is important for NADH/NAD(+) redox homeostasis in cancer cells

The Warburg effect describes an increase in aerobic glycolysis and enhanced lactate production in cancer cells. Lactate dehydrogenase A (LDH-A) regulates the last step of glycolysis that generates lactate and permits the regeneration of NAD(+). LDH-A gene expression is believed to be upregulated by both HIF and Myc in cancer cells to achieve increased lactate production. However, how oncogenic signals activate LDH-A to regulate cancer cell metabolism remains unclear. We found that the oncogenic receptor tyrosine kinase FGFR1 directly phosphorylates LDH-A. Phosphorylation at Y10 and Y83 enhances LDH-A activity by enhancing the formation of active, tetrameric LDH-A and the binding of LDH-A substrate NADH, respectively. Moreover, Y10 phosphorylation of LDH-A is common in diverse human cancer cells, which correlates with activation of multiple oncogenic tyrosine kinases. Interestingly, cancer cells with stable knockdown of endogenous LDH-A and rescue expression of a catalytic hypomorph LDH-A mutant, Y10F, demonstrate increased respiration through mitochondrial complex I to sustain glycolysis by providing NAD(+). However, such a compensatory increase in mitochondrial respiration in Y10F cells is insufficient to fully sustain glycolysis. Y10 rescue cells show decreased cell proliferation and ATP levels under hypoxia and reduced tumor growth in xenograft nude mice. Our findings suggest that tyrosine phosphorylation enhances LDH-A enzyme activity to promote the Warburg effect and tumor growth by regulating the NADH/NAD(+) redox homeostasis, representing an acute molecular mechanism underlying the enhanced lactate production in cancer cells.     

3-Bromopyruvate antagonizes effects of lactate and pyruvate, synergizes with citrate and exerts novel anti-glioma effects

Oxidative stress-energy depletion therapy using oxidative stress induced by D-amino acid oxidase (DAO) and energy depletion induced by 3-bromopyruvate (3BP) was reported recently (El Sayed et al., Cancer Gene Ther., 19, 1–18, 2012). Even in the presence of oxygen, cancer cells oxidize glucose preferentially to produce lactate (Warburg effect) which seems vital for cancer microenvironment and progression. 3BP is a closely related structure to lactate and pyruvate and may antagonize their effects as a novel mechanism of its action. Pyruvate exerted a potent H₂O₂ scavenging effect to exogenous H₂O₂, while lactate had no scavenging effect. 3BP induced H₂O₂ production. Pyruvate protected against H₂O₂-induced C6 glioma cell death, 3BP-induced C6 glioma cell death but not against DAO/D-serine-induced cell death, while lactate had no protecting effect. Lactate and pyruvate protected against 3BP-induced C6 glioma cell death and energy depletion which were overcome with higher doses of 3BP. Lactate and pyruvate enhanced migratory power of C6 glioma which was blocked by 3BP. Pyruvate and lactate did not protect against C6 glioma cell death induced by other glycolytic inhibitors e.g. citrate (inhibitor of phosphofructokinase) and sodium fluoride (inhibitor of enolase). Serial doses of 3BP were synergistic with citrate in decreasing viability of C6 glioma cells and spheroids. Glycolysis subjected to double inhibition using 3BP with citrate depleted ATP, clonogenic power and migratory power of C6 glioma cells. 3BP induced a caspase-dependent cell death in C6 glioma. 3BP was powerful in decreasing viability of human glioblastoma multiforme cells (U373MG) and C6 glioma in a dose- and time-dependent manner.     

GPC3对肝癌细胞糖酵解的调控作用研究

目的:探讨GPC3(glypican 3)在肝癌细胞糖酵解中的调控作用。方法:采用si RNA(small interfering RNA)干扰肝癌细胞中GPC3的表达后,采用q PCR(quantitative PCR)与Western blot实验检测肿瘤糖酵解关键调控分子Glut1(glucose transporter-1)、HK2(hexokinase 2)与LDH-A(Lactate Dehydrogenase A)的表达,通过检测培养液中葡萄糖的减少量分析GPC3对细胞葡萄糖摄取情况,通过检测培养液中乳酸含量与PH值分析GPC3对细胞乳酸产生的影响,通过检测细胞的氧耗速率,分析GPC3对线粒体氧化磷酸化功能的影响。结果:干扰肝癌细胞中GPC3的表达可抑制糖酵解关键调控分子Glut1、HK2与LDH-A表达,降低肝癌细胞葡萄糖摄取速率和细胞氧耗速率,且细胞培养液PH升高,乳酸产生减少。结论:肝癌细胞中GPC3高表达通过上调糖酵解关键调控分子Glut1、HK2与LDH-A表达而促进肝癌细胞糖酵解效应,同时抑制线粒体氧化磷酸化活性。这些结果进一步提示糖代谢重编程可能是GPC3促进肝癌增殖与转移的重要机制。     

Suppression of FAM83D Inhibits Glioma Proliferation,Invasion and Migration by Regulating the AKT/mTOR Signaling Pathway

ObjectiveTo explore the mechanism by which the family with sequence similarity 83, member D (FAM83D)-mediated AKT/mTOR signaling pathway activation affects the proliferation and metastasis of glioma cells.MethodsFAM83D protein expression in glioma cells and tissues was detected by western blotting. Glioma U87 and U251 cells were selected and divided into the Mock, siNC, siFAM83D, FAM83D, MK2206 and FAM83D + MK2206 groups. Cell proliferation was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and clone formation assays, while invasion and migration were evaluated by Transwell assays and wound healing tests. The protein expression of members of the AKT/mTOR pathway was determined via western blotting. Xenograft models were also established in nude mice to observe the in vivo effect of FAM83D on the growth of glioma.ResultsFAM83D was upregulated in glioma patients, especially in those with Stage III-IV. In addition, cells treated with siFAM83D had significant downregulation of p-AKT/AKT and p-mTOR/mTOR, with decreased proliferation and colony numbers, as well as decreased invasion and migration compared to the Mock group. However, FAM83D overexpression could activate the Akt/mTOR pathway and promote the proliferation, invasion and migration of glioma cells. Moreover, treatment with MK2206, an inhibitor of AKT, reversed the promoting effect of FAM83D on the growth of glioma cells. The in vivo experiments demonstrated that silencing FAM83D could inhibit the in vivo growth of glioma cellsConclusionFAM83D was upregulated in glioma and silencing FAM83D suppressed the proliferation, invasion and migration of glioma cells via inhibition of the AKT/mTOR pathway.