Protection against cell death and sustained tyrosine hydroxylase phosphorylation in hydrogen peroxide- and MPP+-treated human neuroblastoma cells with melatonin

Abstract:  Neuroprotective effects of melatonin against oxidative stress-induced neuronal cell degeneration in human SH-SY5Y neuroblastoma cells were investigated in this report. The results demonstrate that exogenous administration of H₂O₂ and 1-methyl, 4-phenyl, pyridinium ion (MPP⁺) significantly decreased cell viability in SH-SY5Y cultured cells. Desipramine, a monoamine uptake blocker was able to abolish the toxic effects of MPP⁺ but not H₂O₂ in reduction of cell viability. Conversely, melatonin reversed the toxic effects of H₂O₂ and MPP⁺ on cell viability. In addition, the reduction of phosphorylation of tyrosine hydroxylase, the rate limiting enzyme in dopamine synthesis, and phosphorylation of cyclic AMP responsive element-binding protein by H₂O₂ and MPP⁺ was also diminished by melatonin. These results demonstrate some effective roles of melatonin on neuroprotection and its action on the modulation of tyrosine hydroxylase phosphorylation.     

The protective effect of melatonin on methamphetamine‐induced calpain‐dependent death pathway in human neuroblastoma SH‐SY5Y cultured cells

Abstract: Methamphetamine (METH) is a potent psychostimulant drug that may cause neuronal cell degeneration. The underlying mechanisms of METH‐induced neuronal toxicity remains poorly understood. In this study, we investigated an important role of calpain‐dependent cascades in methamphetamine‐induced toxicity in human dopaminergic neuroblastoma SH‐SY5Y cultured cell lines. In addition, the protective effect of melatonin against METH‐induced calpain‐dependent death pathway was also investigated. The results of this study show that METH significantly decreased cell viability and tyrosine hydroxylase phosphorylation in SH‐SY5Y cultured cells. Melatonin reversed the toxic effect of METH by inducing cell viability. In addition, melatonin was able to restore the reduction in mitochondrial function and phosphorylation of tyrosine hydroxylase in SH‐SY5Y treated cells. An induction of calpain expression and activity but a reduction of calpain inhibitor (calpastatin) protein levels were observed in SH‐SY5Y cells treated with METH but these effects were diminished by melatonin. These results implicated calpain‐dependent death pathways in the processes of METH‐induced toxicity and also indicated that melatonin has the capacity to reverse this toxic effect in SH‐SY5Y cultured cells.     

Melatonin inhibits MPP+-induced caspase-mediated death pathway and DNA fragmentation factor-45 cleavage in SK-N-SH cultured cells

Neurodegenerative diseases such as Parkinson's disease are illnesses associated with high morbidity and mortality with few, or no effective, options available for their treatment. In addition, the direct cause of selective dopaminergic cell loss in Parkinson's disease has not been clearly understood. Taken together, several studies have demonstrated that melatonin has a neuroprotective effect both in vivo and in vitro. Accordingly, the effects of melatonin on 1-methyl, 4-phenyl, pyridinium ion (MPP(+))-treated cultured human neuroblastoma SK-N-SH cell lines were investigated in the present study. The results showed that MPP(+) significantly decreased cell viability. By contrast, an induction of phosphorylation of c-Jun, activation of caspase-3 enzyme activity, cleavage of DNA fragmentation factors 45 and DNA fragmentation were observed in MPP(+)-treated cells. These changes were diminished by melatonin. These results demonstrate the cellular mechanisms of neuronal cell degeneration induced via c-Jun-N-terminal kinases and caspase-dependent signaling, and the potential role of melatonin on protection of neuronal cell death induced by this neurotoxin.     

Galanin receptor subtype GalR2 mediates apoptosis in SH-SY5Y neuroblastoma cells

Recently we have shown that galanin binding significantly correlates with survival in neuroblastoma patients, indicating a possible modulatory role of galanin receptors in neuroblastic tumor biology. However, the molecular mechanisms beyond this correlation have not been elucidated. Here, the cellular effects on activation of specific galanin receptor subtypes in human SH-SY5Y neuroblastoma cells were analyzed using a tetracycline-controlled expression system. Pharmacological studies confirmed the inducible expression of high affinity binding sites for galanin in SH-SY5Y cells transfected with the galanin receptors GalR1 (SY5Y/GalR1) and GalR2 (SY5Y/GalR2). Microphysiometry revealed that both receptor subtypes were able to mediate an intracellular signal upon galanin application. Interestingly, induction of receptor expression and treatment with 100 nm galanin resulted in a dramatic decrease in cell viability in SY5Y/GalR2 cells (93 +/- 3%) compared with a less pronounced effect in SY5Y/GalR1 cells (19 +/- 10%). The antiproliferative potency of galanin was 100-fold higher in SY5Y/GalR2 (50% effective concentration, 1.1 nm) than in SY5Y/GalR1 cells (50% effective concentration, 190 nm). Furthermore, activation of receptor expression and exposure to galanin resulted in apparent morphological changes indicative of apoptosis in SY5Y/GalR2 cells only. Induction of cell death by the apoptotic process was confirmed by poly-(ADP-ribose)-polymerase cleavage, caspase-3 activation, and the typical laddering of DNA. This study indicates that a high level of GalR2 expression is able to inhibit cell proliferation and induce apoptosis in neuroblastoma cells and therefore identifies GalR2 as a possible target for pharmacological intervention in neuroblastoma.     

Melatonin prevents hydrogen peroxide-induced Bax expression in cultured rat astrocytes

During oxidative stress, cell apoptosis is promoted through the mitochondrial death pathway. Increased reactive oxygen species (ROS) are linked to excess cell loss and mediate the induction of apoptosis in various cell types. However, the role of ROS in the apoptotic pathway has not been clearly established. The aims of this study were to investigate the biochemical and morphological responses of rat astrocytes to hydrogen peroxide-mediated cell death and to define the role that melatonin might play in the apoptotic cascade. Hydrogen peroxide (H2O2; 0.1-1.0 mM) significantly reduced cell viability. Astrocyte death was associated with enhanced ROS production in a dose-dependent manner, as measured by 2',7'-dichloro-fluorescein fluorescence. H2O2-induced cell death was found to be mediated through an apoptotic pathway as treated cells exhibited cell shrinkage, nuclear condensation and marked DNA fragmentation. H2O2 also triggered caspase-3 activation and Bax expression. The ability of different antioxidants to prevent H2O2-induced apoptosis was examined by pre-incubating rat astrocytes with N-acetylcysteine (10 mM), glutathione (0.5 mM) or melatonin (0.1 mM and 10 nM). Results showed that N-acetylcysteine and glutathion can protect astrocytes against ROS accumulation and caspase-3 activation, whereas 0.1 mM melatonin can inhibit H2O2-induced apoptosis by regulating Bax expression and by inhibiting caspase-3 activation. Antiapoptotic effect of 10 nM melatonin associated to inhibition of Bax expression, give rise to new therapeutic approaches.     

Inhibition of proliferation and induction of apoptosis by melatonin in human myeloid HL-60 cells

Melatonin is an indoleamine that is synthesized in the pineal gland and has an extensive repertoire of biological activities. In the present study, we found that melatonin reduced the growth of the human myeloid leukemia cells HL-60, inhibiting progression from G(1) to S phase of the cell cycle and increasing apoptotic cell death. Furthermore, melatonin treatment elevated cytochrome c release from mitochondria and augmented caspase-3 and caspase-9 activities. Upregulation of Bax and downregulation of Bcl-2 was also observed upon melatonin treatment. The effects of melatonin were found not to be mediated by membrane receptors for the indoleamine. Together, our results suggest that melatonin reduces the viability of HL-60 cells via induction of apoptosis primarily through regulation of Bax/Bcl-2 expression.     

Reactive Oxygen Species (ROS) Are Not a Key Determinant for Zika Virus-Induced Apoptosis in SH-SY5Y Neuroblastoma Cells

Introduction: ZIKV is a highly neurotropic virus that can cause the death of infected neuroprogenitor cells through mitochondrial damage and intrinsic apoptotic signaling. In this context, the role of reactive oxygen species (ROS) in neuronal cell death caused by ZIKV still remains elusive. Objective: We aimed at evaluating the role of these cellular components in the death of human undifferentiated neuroblastoma cell line infected with ZIKV. Results: ZIKV infection resulted in the extensive death of SH-SY5Y cells with the upregulation of several genes involved in survival and apoptotic responses as well as the colocalization of mitochondrial staining with ZIKV Envelope (E) protein. Notably, levels of intracellular reactive oxygen species (ROS) were not altered during ZIKV infection in undifferentiated SH-SY5Y cells, and consistent with these results, the treatment of infected cells with the widely studied ROS scavenger N-acetylcysteine (NAC) did not prevent cell death in these cells. Conclusion: Altogether, our results suggest that excessive ROS production is not the main trigger of SH-SY5Y cells death in ZIKV infection.     

Inhibition of insulin-like growth factor-I signaling by ethanol in neuronal cells

BACKGROUND: Ethanol inhibits insulin-like growth factor-I receptor (IGF-IR) activation. However, the potency of ethanol for inhibition of the IGF-IR and other receptor tyrosine kinases varies considerably among different cell types. We investigated the effect of ethanol on IGF-I signaling in several neuronal cell types. METHODS: IGF-I signaling was examined in SH-SY5Y neuroblastoma cells, primary cultured rat cerebellar granule neurons, and rat NG-108 neuroblastoma x glioma hybrids. The tyrosine phosphorylation of IGF-IR, IRS-2, Shc, and p42/p44 MAP kinase (MAPK), and the association of Grb-2 with Shc, were examined by immunoprecipitations and Western blotting. RESULTS: IGF-I-mediated tyrosine phosphorylation of MAPK was inhibited by ethanol in all cell lines. IGF-IR autophosphorylation was markedly inhibited by ethanol in SH-SY5Y cells, was only mildly inhibited in cerebellar granule neurons, and was unaffected in rat NG-108 cells. In vitro tyrosine autophosphorylation of immunopurified IGF-IR obtained from all cell lines was inhibited by ethanol. There was also differential ethanol sensitivity of IRS-2 and Shc phosphorylation, and the association of Shc with IRS-2, among the different cell types. CONCLUSIONS: The findings demonstrate that IGF-I-mediated MAPK activation is a sensitive target of ethanol in diverse neuronal cell types. The data are consistent with ethanol-induced inhibition of IGF-IR activity, although the extent of IGF-IR tyrosine autophosphorylation per se is a poor marker of the inhibitory action of ethanol on this receptor. Furthermore, despite uniform inhibition of MAPK in the different neuronal cell types, tyrosine phosphorylation of proximal mediators of the IGF-IR are differentially inhibited by ethanol.     

Attenuation of oxidative stress-induced neuronal cell death by Hydnophytum formicar-um Jack.

Objective: To investigate protective effects of Hydnophytum formicarum Jack.(H. formicarum) extracts via regulation of SIRT1-FOXO3a-ADAM10 signaling and antioxidant activity against H_2O_2-induced neurotoxicity in neuroblastoma SH-SY5Y cells. Methods: Cell viability and apoptosis of neuronal cells pretreated with H. formicarum Jack. extracts under oxidative stress were determined by MTT assay and flow cytometry. The intracellular reactive oxygen species(ROS) was performed using Carboxy-DCFDA assay. Additionally, a profile of protein expressions related to neuroprotection was detected by western blot analysis. Results: The plant extracts(methanol and ethyl acetate) elicited protective effects on the neuronal cell death as performed by the MTT assay and by apoptosis analysis via the activation of BCL-2. Both ethyl acetate and methanol extracts exerted inhibitory effects against H_2O_2-induced ROS generation in the SH-SY5Y cells. Furthermore, the possible mechanism of neuroprotection of H. formicarum Jack. was observed through its antioxidant properties by maintaining the levels of catalase and SOD2 proteins as well as activating SIRT1-FOXO3a pathway. Importantly, pretreatment of neuronal cells with H. formicarum Jack. significantly recovered the levels of ADAM10 protein compared with the H_2O_2 treatment alone. Conclusions: The recent findings suggest the protective effects of H. formicarum Jack. plant extracts on attenuating H_2O_2-induced neurotoxicity in human SH-SY5Y cells.     

Melatonin induces apoptosis in human neuroblastoma cancer cells

Low concentrations (nanomolar) of melatonin had been previously shown to inhibit cell proliferation in several cancer cell lines as well as in experimental animal models. Additionally, cell growth inhibition and differentiation of prostate cancer cell lines by high concentrations (micromolar to millimolar) of melatonin have been recently reported. In the present paper, we show the induction of apoptosis by high doses of melatonin in the human neuroblastoma cell line SK-N-MC. We found accumulation of cells in the G2/M cell cycle phase and induction of cellular death, measured as lactate dehydrogenase (LDH) released into the culture medium, under millimolar concentration of melatonin. Apoptosis was evaluated using 4,6-diamidino-2-phenylindole staining, DNA gel electrophoresis, electron microscopy, and annexin V binding. Apoptosis progressed through the classical pathway, which involves caspase-3 activation. Cell death was dose and time-dependent; the lowest effective concentration of melatonin was 100 microm. Treatment with 1 mm melatonin for 6 days induced cell death in 75% of the cells. This novel finding shows that a nontoxic natural indoleamine may be potential therapy for some types of human neuroblastomas.     

Melatonin prevents nitric oxide-induced apoptosis by increasing the interaction between 14-3-3beta and p-Bad in SK-N-MC cells.

The anti-apoptotic effect of melatonin has been described in vivo and in vitro. A previous report has revealed that melatonin suppresses nitric oxide (NO)-induced apoptosis via the induction of Bcl-2 expression in PGT-beta pineal cells. To investigate the protective mechanism of melatonin on NO donor S-nitroso-N-acetyl-penicillamine (SNAP)-induced apoptosis, we examined the anti-apoptotic upstream signaling pathway of Bcl-2 in the human neuroblastoma cell line SK-N-MC. The flow cytometry results revealed that apoptosis occurred in NO-treated cells, while cell death was inhibited by pretreatment with melatonin (100 microm). In addition, decreased Bax expression, increased Bcl-2 expression and a decreased release of cytochrome c into the cytosol were observed in the melatonin-pretreated SK-N-MC cells. We also found that melatonin treatment induced the activation of Akt/PKB and the phosphorylation of GSK3alpha/beta and Bad. Furthermore, melatonin treatment not only increased the protein-protein interactions between 14-3-3beta and p-Bad, but also decreased the release of cytochrome c from mitochondria into the cytosol. In summary, the protective effect of melatonin against NO-induced apoptosis was mediated by the inhibition of Bad translocation from the cytosol to the mitochondria by the induction of protein-protein interactions between 14-3-3beta and p-Bad.     

Gene transfer of the JNK interacting protein-1 protects dopaminergic neurons in the MPTP model of Parkinson's disease

Increasing evidence suggests that apoptosis may be the underlying cell death mechanism in the selective loss of dopaminergic neurons in Parkinson's disease. Because the inhibition of caspases provides only partial protection in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/1-methyl-4-phenylpyridinium (MPTP/MPP(+)) model of Parkinson's disease, we investigated the role of the proapoptotic c-Jun N-terminal kinase (JNK) signaling cascade in SH-SY5Y human neuroblastoma cells in vitro and in mice in vivo. MPTP/MPP(+) led to the sequential phosphorylation and activation of JNK kinase (MKK4), JNK, and c-Jun, the activation of caspases, and apoptosis. In mice, adenoviral gene transfer of the JNK binding domain of JNK-interacting protein-1 (a scaffold protein and inhibitor of JNK) inhibited this cascade downstream of MKK4 phosphorylation, blocked JNK, c-Jun, and caspase activation, the death of dopaminergic neurons, and the loss of catecholamines in the striatum. Furthermore, the gene transfer resulted in behavioral benefit. Therefore, inhibition of the JNK pathway offers a new treatment strategy for Parkinson's disease that blocks the death signaling pathway upstream of the execution of apoptosis in dopaminergic neurons, providing a therapeutic advantage over the direct inhibition of caspases.     

APP5肽类似物165对链脲佐菌素损伤SH-SY5Y细胞的保护作用

目的探讨体外APP5肽类似物165（下称P165）对链脲佐菌素（STZ）损伤SH-SY5Y细胞的保护作用。方法STZ0.8mmol/L作用于SH-SY5Y细胞的损伤模型。通过测定噻唑蓝（MTT）代谢率、乳酸脱氢酸（LDH）漏出率,瑞氏染色观察细胞形态,Western blot检测相关蛋白,观察P165的保护作用。结果与正常对照组细胞的MTT代谢率（1.00±0.01）和LDH漏出率（201.56±47.54）比较,STZ损伤组细胞MTT代谢率降低（0.84±0.01）,LDH漏出率升高（317.83±76.95）,差异有统计学意义（P〈0.05）,细胞胞体面积缩小,胰岛素信号通路相关蛋白IRS-1、PI3K表达减少;P16530μmol/L组细胞MTT代谢率升高（0.91±0.01）,LDH漏出率降低（228.53±35.65）,细胞形态恢复正常,胰岛素信号通路相关蛋白IRS-1、PI3K表达恢复正常。结论体外STZ与SH-SY5Y细胞共孵育,可能影响胰岛素/胰岛素受体信号转导系统对细胞的促生长作用,而P165可能通过激活该信号通路逆转这种损伤,可作为一种神经营养因子起到保护作用。     

Melatonin prevents nitric oxide-induced apoptosis by increasing the interaction between 14-3-3β and p-Bad in SK-N-MC cells

Abstract:  The anti-apoptotic effect of melatonin has been described in vivo and in vitro. A previous report has revealed that melatonin suppresses nitric oxide (NO)-induced apoptosis via the induction of Bcl-2 expression in PGT-β pineal cells. To investigate the protective mechanism of melatonin on NO donor S -nitroso- N -acetyl-penicillamine (SNAP)-induced apoptosis, we examined the anti-apoptotic upstream signaling pathway of Bcl-2 in the human neuroblastoma cell line SK-N-MC. The flow cytometry results revealed that apoptosis occurred in NO-treated cells, while cell death was inhibited by pretreatment with melatonin (100 μ m ). In addition, decreased Bax expression, increased Bcl-2 expression and a decreased release of cytochrome c into the cytosol were observed in the melatonin-pretreated SK-N-MC cells. We also found that melatonin treatment induced the activation of Akt/PKB and the phosphorylation of GSK3α/β and Bad. Furthermore, melatonin treatment not only increased the protein–protein interactions between 14-3-3β and p-Bad, but also decreased the release of cytochrome c from mitochondria into the cytosol. In summary, the protective effect of melatonin against NO-induced apoptosis was mediated by the inhibition of Bad translocation from the cytosol to the mitochondria by the induction of protein–protein interactions between 14-3-3β and p-Bad.     

CCR5 mediates Fas- and caspase-8 dependent apoptosis of both uninfected and HIV infected primary human CD4 T cells

DESIGN: HIV Env interaction with the corresponding chemokine receptor dictates the molecular mechanism of death of both HIV-infected and uninfected primary CD4 T cells. CXCR4/T tropic HIV virus (X4) triggers CD4 T cell death through a caspase independent mechanism, whereas CCR5/M tropic HIV virus (R5) HIV triggers a caspase dependent death. In the present study, we have investigated the pathway whereby R5 Env-CR5 interactions lead to a caspase dependent cell death. METHODS: CD4 T cells were infected with X4 or R5 HIV strains, or were mock infected. After infection, cells were treated with caspase inhibitors or decoys of death receptor signaling pathways and cell viability was analyzed. The role of R5 HIV Env in induction of cell death of uninfected T cells was analyzed by co-culturing uninfected CD4 T cells with R5 Env expressing cells in the absence or presence of various inhibitors of death receptor signaling. RESULTS: Infection of CD4 T cells with R5, but not with X4 HIV strains results in the activation of caspase-8 and cell death that is reversed by a decoy of the Fas receptor. Isolated activation of CCR5 by membrane-bound, or soluble R5 Env causes a Fas- and caspase-8 dependent death also of uninfected CD4 T cells. Additional studies demonstrate that isolated CCR5 activation by R5 Env leads to both de novo expression of FasL and induction of susceptibility to Fas-mediated apoptosis in resting primary CD4 T cells. CONCLUSIONS: These results ascribe to CCR5 a novel role in activating the Fas pathway and caspase-8 as well as triggering FasL production when activated by R5 Env, ultimately causing CD4 T cell death.     

Antiproliferative effects of melatonin on the growth of rat pituitary prolactin-secreting tumor cells in vitro

Earlier studies showed that melatonin reduced the growth of 17-beta-estradiol (E(2))-induced rat pituitary prolactin-secreting tumor (prolactinoma) in vivo. The mechanisms of melatonin's inhibitory action on the prolactin-secreting tumor were further explored by investigating the in vitro effects of melatonin on the growth of pituitary prolactin-secreting tumor cells. Primary cultured prolactinoma cells from E(2)-induced rat pituitary prolactin-secreting tumor were treated with 10(-5), 10(-4) or 10(-3) m melatonin for 5 days. Apoptosis was evaluated using flow cytometry and the TdT-mediated dUTP nick-end labeling (TUNEL) method. In addition, cell viability was analyzed by (3,4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It was found that incubation of prolactinoma cells with 10(-5), 10(-4) or 10(-3) m melatonin for 5 days inhibited cell growth and increased cell apoptosis. Furthermore, melatonin increased caspase-3 activity, Bax mRNA expression, and cytochrome c protein expression. Conversely, Bcl-2 mRNA expression and mitochondrial membrane potential were inhibited by melatonin treatment. Our results further suggest that melatonin inhibits tumor growth by inducing apoptosis of rat pituitary prolactin-secreting tumor directly via the damage of mitochondria.     

川陈皮素抑制Aβ25~35诱导的SH-SY5Y细胞氧化应激与凋亡作用

目的探讨川陈皮素对β淀粉样蛋白(Aβ)25~35诱导的SH-SY5Y细胞损伤的保护作用及潜在机制。方法SH-SY5Y细胞培养至对数生长期,分为正常对照组、Aβ_25~35损伤组及川陈皮素25、50、100μmol/L组,培养24 h后检测细胞存活率、氧化应激水平、凋亡率、凋亡相关基因及磷酸化-蛋白激酶B(p-Akt)、磷酸化-雷帕霉素靶蛋白(p-mTOR)蛋白表达等指标。结果与Aβ_25~35损伤组比较,川陈皮素各浓度处理组SH-SY5Y细胞的存活率显著增加(P<0.05),而乳酸脱氢酶(LDH)活性显著降低(P<0.05);与Aβ_25~35损伤组比较,川陈皮素各浓度处理组SH-SY5Y细胞谷胱甘肽过氧化酶(GSH-Px)、过氧化氢酶(CAT)活性显著增加(P<0.05),而丙二醛(MDA)含量显著降低(P<0.05);给予不同浓度川陈皮素处理后,与Aβ_25~35损伤组比较,SH-SY5Y细胞凋亡率、Bax mRNA表达显著降低(P<0.05),而Bcl-2 mRNA、Bcl-2/Bax值、p-Akt及p-mTOR蛋白表达显著增加(P<0.05)。结论川陈皮素可以通过调控Akt/mTOR通路抑制Aβ_25~35诱导的SH-SY5Y细胞氧化应激及凋亡,进而对Aβ_25~35诱导的SH-SY5Y细胞损伤产生保护作用。     

Long noncoding RNA HAND2-AS1 reduced the viability of hepatocellular carcinoma via targeting microRNA-300/SOCS5 axis

BackgroundHepatocellular carcinoma (HCC) is one of the most prevalent human cancers with high mortality. Long non-coding RNA heart and neural crest derivatives expressed 2 anti-sense 1 (HAND2-AS1) is down-regulated in several cancers including HCC, yet the precise mechanisms how HAND2-AS1 regulates cell survival in HCC remains poorly understood.MethodsThe expression levels of HAND2-AS1 and miR-300 were measured using quantitative real-time PCR. The protein levels of suppressor of cytokine signaling 5 (SOCS5), Bcl-2, Bax and cleaved caspase-3 were determined by Western blot. Cell viability and cell proliferation were assessed using cell counting kit-8 and clone formation assay, respectively. Cell apoptosis was detected using flow cytometry. The interactions between HAND2-AS1 and miR-300, miR-300 and SOCS5 were validated using luciferase reporter assay.ResultsHAND2-AS1 was down-regulated in HCC tissues and cell lines, and the expression level of HAND2-AS1 was positively correlated to patient survival. HAND2-AS1 over-expression reduced viability and proliferation in HCC cells. Elevated HAND2-AS1 level induced apoptosis in HCC cells, accompanied with increased Bax and cleaved caspase-3 levels and decreased Bcl-2 level. We also validated that HAND2-AS1 acted as a sponge of miR-300, and there was a negative correlation between expression levels of HAND2-AS1 and miR-300 in HCC tissues. Furthermore, we found that SOCS5 was a downstream target of miR-300. In addition, miR-300 mimics abolished HAND2-AS1-mediated inhibition of cell viability and proliferation. miR-300 mimics also reversed the HAND2-AS1-induced apoptosis in HCC cells.ConclusionlncRNA HAND2-AS1 inhibits proliferation in HCC through regulating miR-300/SOCS5 axis.