Putative binding sites for benzocaine on a human cardiac cloned channel (Kv1.5)

OBJECTIVES: It has been demonstrated that at nanomolar concentrations benzocaine increased, whereas at micromolar concentrations, it blocked hKv1.5 channels in a voltage-dependent manner and modified the voltage-dependence of channel activation. The present study was undertaken to localize the putative binding sites involved in the 'agonists' and blocking effects of benzocaine. METHODS: Experiments were carried out on wild-type and site directed mutated hKv1.5 channels stably expressed on Ltk(-) cells using the whole-cell patch-clamp. RESULTS: At 35 mM [K+](i) the voltage-dependent unblock produced by 500 microM benzocaine was preserved at both 4 and 140 mM [K+](o). Mutations located in the inner mouth of the pore (T477S, T505A, L508M and V512M) abolished the agonist but increased the blocking effects of benzocaine. Intracellular application of tetraethylammonium (3 mM) abolished the 'agonist' effects whereas the blocking effects of benzocaine remained unaltered. Block induced by benzocaine and intracellular tetraethylammonium was additive. In contrast, the combination of benzocaine and bupivacaine (>25 microM) produced less blockade than bupivacaine alone. However, mutation of the extracellular residue R485Y did not modify the effects of benzocaine. Extracellular application of tetraethylammonium (100 mM) did not modify the agonist effects of benzocaine, but abolished the voltage- and time-dependence of benzocaine-induced block. CONCLUSIONS: The results suggested that benzocaine binds with high affinity to an intracellular binding site to produce 'agonist' effects and to a low affinity subsite, which is also located in the inner mouth, to produce the blocking effects. Furthermore, benzocaine and extracellular K(+) interact to modify the voltage-dependence of channel opening.     

Water-soluble specific growth hormone binding sites from cultured human lymphocytes: preparation and partial characterization.

Cultured human lymphocytes (IM-9 cell line) have specific binding sites or receptors for human growth hormone (hGH). Under appropriate conditions, this specific binding material is spontaneously released into the incubation medium and is solubilized without the use of detergents. This water-soluble preparation binds [125I]iodo-hGH with the same specifictiy as receptors on the intact cell. Unlabeled hGH, but not porcine growth hormone or insulin, competes with labeled hGH for binding to the soluble preparation. Growth hormone preparations of varying purity compete for binding to the soluble binding preparation in the same rank order as they compete for binding to the intact IM-9 lymphocyte. [125I]iodo-hGH incubated with, but not bound to, the soluble preparation is partially degraded, while the [125I]iodo-hGH that is bound to the soluble preparation is protected from degradation, and its ability to rebind to fresh cells is enhanced. The [125I]iodo-hGH-soluble binding preparation complex can be dissociated by the addition of large quantities of unlabeled hGH or by lowering the pH, and [125I]iodo-hGH in both instances remains intact and undegraded. The soluble binding preparation did not sediment when centrifuged at 200,000 X g for 4 hours and was not retained on 0.20 micron Millipore filters. The soluble binding preparation was not retarded on Sephadex G-200. Binding activity was abolished by tryptic digestion. These studies demonstrate that hGH-binding sites, like previously reported insulin binding sites, can be spontaneously solubilized from cultured human lymphocytes, without the use of detergents; these soluble binding preparations are of high molecular weight and are, at least in part, protein in nature.     

beta-Endorphin: characterization of binding sites specific for the human hormone in human glioblastoma SF126 cells.

The established human glioblastoma cell line SF126 was found to bind tritiated human beta-endorphin (beta h-EP) in a saturable fashion. From displacement studies, the ED50 was estimated to be about 2.5 nM. The Kd was estimated as 1.9 X 10(-9) M and Scatchard analysis showed a biphasic pattern with a predominant low-affinity component. Binding reached a maximum at about 90 min at 22 degrees C and was instantaneously reversible. Tritiated [D-Ala2,D-Leu5]enkephalin and tritiated dihydromorphine did not bind to the cells. Sodium at a concentration of 150 mM decreased the specific binding by 80%. The interaction with the cellular binding site appeared to be mediated by the COOH-terminal segment of beta h-EP, as beta h-EP-(6-31) retained a high potency for displacing tritiated beta h-EP, and beta h-EP-(1-27) has no activity. Camel beta-EP was only about 1% as active as the human hormone.     

Immunomodulatory role of melatonin: specific binding sites in human and rodent lymphoid cells

Abstract: This paper reviews the evidence that supports the hypothesis of the existence of specific binding sites for melatonin on immune cells. These binding sites have been described in human blood lymphocytes and granulocytes, and thymus, spleen, and bursa of Fabricius from different rodents and birds. The dissociation constant values of these binding sites are in the 0.1 -1 nM range, suggesting that melatonin may play a physiological role in lymphocyte regulation. Moreover, melatonin binding sites appear to be modulated by guanine nucleotides. Therefore, in addition to other mechanisms described for the regulation of immune function by melatonin, a direct mechanism of regulation can be involved via binding of melatonin by immunocompetent cells.     

Evidence for distinct calcium channel agonist and antagonist binding sites in intact cultured embryonic chick ventricular cells

To determine whether calcium channel agonists and antagonists bind to distinct pharmacologically active sites, the binding of dihydropyridine calcium channel agonists and antagonists was related to calcium flux and contractile state in primary monolayer cultures of spontaneously contracting chick embryo ventricular cells. Equilibrium binding studies using the antagonist (+)-[3H]PN200-110 demonstrated equilibrium binding to intact, beating cells consistent with a single class of binding sites (KD, 1.1 nM; Bmax, 40 fmol/mg protein). Membrane depolarization of the intact cells by incubation in 30 mM potassium caused a 91% increase in the apparent number of (+)-PN200-110 binding sites (Bmax 76 fmol/mg protein), but no significant change in the KD (1.2 nM). The (+)-PN200-110 produced a concentration-dependent decrease in calcium uptake (IC50 2.2 nM) and contractile amplitude (IC50 5.6 nM). The calcium channel agonist, (+/-)-[3H]BAY k 8644, bound to two distinct binding sites with high affinity (KD 1.0 nM) and low affinity (KD 1.9 microM). The (+/-)-BAY k 8644 produced biphasic modulation of calcium flux and contractile state. At concentrations of 100 nM or less, (+/-)-BAY k 8644 increased calcium flux and contractile amplitude, consistent with drug interaction with the high affinity agonist site. However, at higher concentrations, the stimulatory effect of (+/-)-BAY k 8644 on calcium flux and contractile amplitude was abolished, a finding that is consistent with drug interaction with the low affinity antagonist site.(ABSTRACT TRUNCATED AT 250 WORDS)     

Presence of a specific binding site of endothelin on cultured smooth muscle cells

The 21 amino-acids endothelium-derived peptide, endothelin, recently isolated by Yanagisawa et al. (Nature 1988; 33, 411-5) possesses potent vasoconstrictive properties in vivo and in vitro. In the present study, we investigated the binding of endothelin on cultured rat aortic smooth muscle cells using 125I-iodotyrosyl-endothelin labelled by the chloramine T method. 125I-endothelin bound to a single class of hight affinity binding sites in vascular smooth muscle cells. After 2 hours incubation at 37 degrees C, dissociation constant (Kd) was 1.2 +/- 0.3 nM and binding capacity (Bmax) was 59 +/- 11 fmol/10(6) cells (n = 5). 125I-endothelin was displaced by unlabelled endothelin with a inhibition constant (Ki) of 0.2 nM, whereas an absence of competition was observed with 1 microM of vasoactive substances such as angiotensin II, arg-vasopressin, atrial natriuretic factor, histamine, epinephrine and norepinephrine, and with the calcium entry blocks nifedipine, diltiazem and D 600. 125I-endothelin binding was not reversible by addition of unlabelled endothelin (1 microM) and not dissociable by acetic acid (10 mM) or trypsin (0.1 p. 100) treatment of the cells. Furthermore, preincubation of vascular smooth muscle cells with endothelin (1 nM) at 37 degrees C induced a rapid down-regulation of endothelin binding capacity by about 50 p. 100. These data indicate that specific endothelin bindind sites are present in smooth muscle cells, and suggest a tight binding or a rapid captation of endothelin into the cell membrane leading to contractile events.     

Effects of triiodothyronine (T3) and identification of specific nuclear T3-binding sites in cultured human fetal epiphyseal chondrocytes.

The effects of T3 on cultured human fetal epiphyseal chondrocytes were assessed by studying its effects on DNA synthesis and alkaline phosphatase activity. DNA synthesis was evaluated as follows: after 48-h incubation in Ham's F-12 serum-free medium, cultured chondrocytes were incubated with or without T3 (0.1-100 nM) in MCDB-104 serum-free medium for different periods of time (2-10 days), with the addition of [3H]thymidine (5 microCi/mL) for the last 24 h. Confluent cultured chondrocytes in 25-cm2 tissue culture flasks were incubated in Ham's F-12 serum-free medium for up to 9 days with or without T3 (0.1-100 nM); the cellular cytoplasmic fraction was obtained, and alkaline phosphatase activity was evaluated using paranitrophenylphosphate as a substrate. No significant effects of T3 (0.1-100 nM) on DNA-[3H]thymidine incorporation were observed in any experiment (n = 17) for any gestational age (12-39 weeks) or for any incubation period studied (2-10 days). However, a significant (P less than 0.025 or more) stimulatory effect of T3 (0.1-100 nM) on alkaline phosphatase activity was observed after 9 days of incubation. This effect was highest for 5 nM T3 and was present in cultured chondrocytes from human fetuses of all ages studied (13-40 weeks). Cultured human fetal epiphyseal chondrocytes from human fetuses 12-40 weeks old (n = 8) showed specific nuclear binding sites for T3. The binding capacity was 27.14 +/- 2.84 fmol/100 micrograms DNA, and the Kd was 0.66 +/- 0.14 x 0.1 nM (mean +/- SEM), with no significant differences among fetal ages. In conclusion, our results show that T3 elicits a biological response in cultured human fetal epiphyseal chondrocytes and has specific nuclear binding sites. Since alkaline phosphatase is closely related to the mineralization of epiphyseal cartilage, these results suggest that thyroid hormones could regulate this process.     

DNA binding activity from cultured human fibrolasts that is specific for partially depurinated DNA and that inserts purines into apurinic sites.

A protein of molecular weight approximately 120,000 was isolated from cultured human fibroblasts and HeLa cells on the basis of its ability to bind specifically to apurinic DNA. After separation from apurinic endonuclease activity, the protein was found to incorporate purine, but not pyrimidine, bases specifically into depurinated DNA so as to protect the apurinic sites from alkali. Purine base insertion activity was sensitive to heating and freezing as well as to caffeine and EDTA; it required K+ but not a divalent cation. Guanine, but not adenine, was incorporated into depurinated poly(dG-dC), whereas adenine, but not guanine, was incorporated into poly(dA-dT). After incorporation into depurinated DNA, guanine could be reisolated as dGMP. Although this activity suggests an alternative pathway for DNA repair that is independent of nucleotide excision, other functions for such an enzyme are possible.     

Increased potassium transport and ouabain binding in human Rhnull red blood cells.

Potassium (K+) influx and 3H-ouabain binding were studied in human red cells completely lacking the rhesus (Rh) antigens (Rhnull cells) and compared with normal Rh(D) red cells. The Rhnull cells, originally described by Seidl, Spielmann, and Martin (Vox Sang. 23:182, 1972) were normal in size, cation, and water content, indicating no significant increase in cell volume as occurs in young human red cells. However, the ouabain-insensitive K+ permeability, as well as the ouabain sensitive active K+ transport, were increased 1.6 1.8-and 1.4-1.5-fold, respectively, above the values found in Rh(D) control cells. The Na+K+ ATPase activity of membranes from Rhnull cells was also higher than from Rh(D) cells. Binding studies with 3H-ouabain revealed that at 100% K+ pump inhibition Rhnull cells bound 670 and Rh(D) cells 450-500 ouabain molecules per cell. Since the rate of ouabain binding was identical in Rhnull and Rh(D) control cells, we concluded that the Rhnull cell had about 35%-45% more cation pumps than the Rh(D) cell. These additional pumps in Rhnull cells appeared to be indistinguishable from those in control cells. Anti-D or the serum from the Rhnull individual did not alter cation permeability in Rh(D) red cells. The data suggested that the Rhnull cell, known for its hematologic malfunction, was not a young or prematurely released red cell, but had a pleiotropic membrane defect which also affected the passive and active cation transport system on the molecular level. Our finding precludes a structural identity of the rhesus antigen with the molecules composing the Na+K+ pump system.     

Location of monovalent cation binding sites in the gramicidin channel.

Six syntheses of gramicidin A have been carried out, each with 90% 13 C enrichment of a single carbonyl carbon these being the formyl, Val-1, Trp-9, Trp-11, Trp-13, and Trp-15 carbonyl carbons. Each gramicidin A was incorporated as the channel state into phospholipid structures, and the chemical shift of the carbonyl carbon resonance was monitored by 13C NMR as a function of ion concentration. Plots of Na+- and Tl+-induced chemical shifts as a function of carbonyl location in the channel indicate two symmetrically related binding sites centered at the tryptophan carbonyls and separated by 23 A. The absence of ion-induced chemical shifts for the formyl and Val-1 carbonyl carbon resonances indicates that there is no binding site midway through the channel but rather a central free-energy barrier for ion transit through the channel. Ion induced chemical shifts of the tryptophan carbonyl carbon resonances at 100 mM Na+ verify that the tight binding constant (Kbt congruent to 70 M-1), observed with 23Na NMR, results from binding within the channel. This observation and the lateral, triangular distribution of the coordinating Trp-9, -11, and -13 carbonyls combine to provide an experimental demonstration that the carbonyls of the walls of the channel directly coordinate the ion, successfully competing with the polar solvent. With the binding sites verified and localized, it is possible to conclude that the transport mechanism for Na+ is well represented by the case of the two-site model [D. W. Urry, Venkatachalam, C. M., Spisni, A., Läuger, P. & Khaled, M. A. (1980) Proc. Natl. Acad. Sci. USA 77, 2028--2032].     

Characterization of specific low-density lipoprotein binding sites in human term placental microvillous membranes

Purified microvillous membranes prepared from normal term human placenta were studied for their ability to bind specifically low-density lipoprotein (LDL). Electron microscopic examination of the membrane preparations revealed essentially microvilli-like structures, and the enzyme analyses a 14-17-fold enrichment in the membrane markers 5'-nucleotidase and alkaline phosphatase. The binding of [125I]LDL was dependent on time, temperature, pH and protein concentration; it was saturable with a low capacity (130.4 +/- 22.2 ng/mg of membrane protein) and presented a high affinity (apparent Ka 6.12 +/- 1.32 micrograms protein per ml). These high-affinity binding sites were specific for LDL (high-density lipoprotein induced less competition than unlabelled LDL) and were sensitive to pronase digestion. Unlike the binding of LDL to other tissues, the [125I]LDL binding to microvillous membranes did not require divalent cations. The presence of specific LDL receptors on the placental microvillous membranes, located at the effective site of exchange between the maternal blood and the placental tissue, supports the concept that human placenta utilizes LDL-cholesterol for its progesterone synthesis.     

Properties of hepatic binding sites for prolactin in ring doves (Streptopelia risoria)

Specific binding of 125I-labeled ovine prolactin (125I-oPRL) was detected in crude membrane fractions prepared from ring dove (Streptopelia risoria) liver homogenates. In characterization studies, specific binding was found to depend upon pH, incubation time, incubation temperature, and membrane protein concentration. Competitive inhibition of specifically bound 125I-oPRL was observed with human growth hormone, human and rat prolactin, and dove pituitary extract but not with turkey prolactin, human placental lactogen, and several nonlactogenic hormone preparations. Dove liver membranes showed high affinity (Kd = 3 X 10(-10) M) for binding to oPRL but had relatively low binding capacity (Bmax less than 20 fmol/mg protein). PRL binding activity in pooled liver fractions from breeding doves during early stages of incubation prior to crop sac growth did not differ markedly from that observed in doves sampled at the end of incubation when crop sac weight and serum PRL were elevated. However, binding activity was higher in pooled male liver fractions than in pooled female liver fractions at both reproductive stages. A two- to threefold increase in binding capacity was observed in pooled liver fractions from late-incubating doves following MgCl2-induced binding site desaturation. The MgCl2 treatment did not eliminate the differences in specific binding observed between male and female liver fraction pools, thus suggesting the possibility of sex-specific mechanisms of hepatic PRL binding site regulation in this species. It is concluded that the dove liver possesses specific binding sites for PRL with properties similar, but not identical, to those found in other vertebrate target tissues.     

Production of infectious genotype 1a hepatitis C virus (Hutchinson strain) in cultured human hepatoma cells

Infections with hepatitis C virus (HCV) are marked by frequent viral persistence, chronic liver disease, and extraordinary viral genetic diversity. Although much has been learned about HCV since its discovery, progress has been slowed by a lack of permissive cell culture systems supporting its replication. Productive infections have been achieved recently with genotype 2a virus, but cirrhosis and liver cancer are typically associated with genotype 1 HCV, which is more prevalent and relatively resistant to IFN therapy. We describe production of infectious genotype 1a HCV in cells transfected with synthetic RNA derived from a prototype virus (H77-S). Viral proteins accumulated more slowly in H77-S transfected cells than in cells transfected with genotype 2a (JFH-1) RNA, but substantially more H77-S RNA was secreted into supernatant fluids. Most secreted RNA was noninfectious, banding in isopycnic gradients at a density of 1.04-1.07 gm/cm(3), but infectivity was associated with H77-S particles possessing a density of 1.13-1.14 gm/cm(3). The specific infectivity of H77-S particles (5.4 x 10(4) RNA copies per focus-forming unit) was significantly lower than JFH-1 virus (1.4 x 10(2) RNA copies per focus-forming unit). Infection with either virus was blocked by CD81 antibody. Sera from genotype 1a-infected individuals neutralized H77-S virus, but had little activity against genotype 2a virus, suggesting that these genotypes represent different serotypes. The ability of this genotype 1a virus to infect cultured cells will substantially benefit antiviral and vaccine discovery programs.     

Conjugation of 1-naphthol in human gastric epithelial cells.

The biotransformation of xenobiotics is essential to the maintenance of the body's integrity. Mucosal biotransformation has been well documented in the small and large intestine of animals and humans but whether the gastric mucosa plays a role in detoxifying ingested compounds remains largely unknown. The conjugation of the model phenolic compounds, 1-naphthol, by human gastric epithelial cells was assessed in vitro. Freshly isolated and cultured epithelial cells were prepared from surgical specimens obtained from patients undergoing total gastrectomy for cancer. Cell preparations were incubated with 1- 14C-naphthol over 1 hour and the glucuronide and sulphate conjugates formed were separated by thin-layer chromatography. Conjugation of 1-naphthol was observed with both freshly isolated and cultured cells. In freshly isolated cells, the 1 hour turnover of 1 microM 1-naphthol to its glucuronide and sulphate conjugates averaged 19% and 10% respectively. At higher 1-naphthol concentrations, both types of conjugate were formed at about the same rate, up to saturation (apparent Vmax = 0.07 nmol/mg protein/minute, and apparent Km = 40 microM). In cultured cells, the 1 hour turnover of 1 microM 1-naphthol to its glucuronide and sulphate conjugates averaged 35% and 8% respectively. These results suggest that the human gastric mucosa is a detoxifying organ, and that its role with regard to chemical carcinogenesis and drug first pass metabolism deserves further assessment.     

Somatostatin analog induces insulin-like growth factor binding protein-1 (IGFBP-1) expression in human hepatoma cells.

As the somatostatin analog octreotide suppresses pituitary GH secretion and circulating IGF-1 levels, we examined its effects on human hepatoma (hep G2) cells which selectively express IGFBP-1. Octreotide (60 nM) stimulated IGFBP-1 up to 4.1-fold (p < 0.001 after 24 hrs). Induction of IGFBP-1 was first detectable after 12 hrs of 6 nM octreotide (1.5-fold, p < 0.03), and was confirmed by ligand blotting. Cholera toxin and forskolin induced IGFBP-1 independently and were also additive with octreotide. IGFBP-1 mRNA expression was induced 2.7-fold by octreotide. Thus, octreotide induces basal and stimulated IGFBP-1 in hepatocytes independently of insulin and GH. As IGFBP-1 may regulate peripheral IGF-1 action, induction of IGFBP-1 represents a novel pituitary-independent mechanism for octreotide action.     

Distribution and movement of anionic cell surface sites in cultured human vascular endothelial cells.

Cell surface anionic sites on primary and transformed cultures of human vascular endothelium were studied using cationized ferritin (CF) as an ultrastructural marker. The native distribution of anionic sites on the upper (free) surfaces of cells, fixed in situ with glutaraldehyde, was uniform. Binding of the polycationic ligand, CF, in unfixed cells induced redistribution of anionic sites. Rapid formation of discrete patches of CF particles was followed by reappearance of binding between patches, movement of surface-bound CF into intercellular clefts, and endocytosis, over the next 30 min. Aldehyde-fixed cells, detached from the culture surface, bound CF on both upper and lower surfaces. The distribution and mobility of negatively charged membrane components in vascular endothelium may have relevance for thrombosis, atherogenesis, and vascular permeability.     

Structural basis of action for a human ether-a-go-go-related gene 1 potassium channel activator

Activation of human ether-a-go-go-related gene 1 (hERG1) K(+) channels mediates cardiac action potential repolarization. Drugs that activate hERG1 channels represent a mechanism-based approach for the treatment of long QT syndrome, a disorder of cardiac repolarization associated with ventricular arrhythmia and sudden death. Here, we characterize the mechanisms of action and the molecular determinants for binding of RPR260243 [(3R,4R)-4-[3-(6-methoxy-quinolin-4-yl)-3-oxo-propyl]-1-[3-(2,3,5-trifluoro-phenyl)-prop-2-ynyl]-piperidine-3-carboxylic acid] (RPR), a recently discovered hERG1 channel activator. Channels were heterologously expressed in Xenopus laevis oocytes, and currents were measured by using the two-microelectrode voltage-clamp technique. RPR induced a concentration-dependent slowing in the rate of channel deactivation and enhanced current magnitude by shifting the voltage dependence of inactivation to more positive potentials. This mechanism was confirmed by demonstrating that RPR slowed the rate of deactivation, but did not increase current magnitude of inactivation-deficient mutant channels. The effects of RPR on hERG1 kinetics and magnitude could be simulated by reducing three rate constants in a Markov model of channel gating. Point mutations of specific residues located in the S4-S5 linker or cytoplasmic ends of the S5 and S6 domains greatly attenuated or ablated the effects of 3 microM RPR on deactivation (five residues), inactivation (one residue), or both gating mechanisms (four residues). These findings define a putative binding site for RPR and confirm the importance of an interaction between the S4-S5 linker and the S6 domain in electromechanical coupling of voltage-gated K(+) channels.     

Function of chloride intracellular channel 1 in gastric cancer cells

AIM: To investigate the effect of chloride intracellular channel 1 (CLIC1) on the cell proliferation, apoptosis, migration and invasion of gastric cancer cells.METHODS: CLIC1 expression was evaluated in human gastric cancer cell lines SGC-7901 and MGC-803 by real time polymerase chain reaction (RT-PCR). Four segments of small interference RNA (siRNA) targeting CLIC1 mRNA and a no-sense control segment were designed by bioinformatics technology. CLIC1 siRNA was selected using Lipofectamine 2000 and transfected transiently into human gastric cancer SGC-7901 and MGC-803 cells. The transfected efficiency was observed under fluorescence microscope. After transfection, mRNA expression of CLIC1 was detected with RT-PCR and Western blotting was used to detect the protein expression. Proliferation was examined by methyl thiazolyl tetrazolium and apoptosis was detected with flow cytometry. Polycarbonate membrane transwell chamber and Matrigel were used for the detection of the changes of invasion and migration of the two cell lines.RESULTS: In gastric cancer cell lines SGC-7901 and MGC-803, CLIC1 was obviously expressed and CLIC1 siRNA could effectively suppress the expression of CLIC1 protein and mRNA. Proliferation of cells transfected with CLIC1 siRNA3 was enhanced notably, and the highest proliferation rate was 23.3% (P = 0.002) in SGC-7901 and 35.55% (P = 0.001) in MGC-803 cells at 48 h. The G2/M phase proportion increased, while G0/G1 and S phase proportions decreased. The apoptotic rate of the CLIC1 siRNA3 group obviously decreased in both SGC-7901 cells (62.24%, P = 0.000) and MGC-803 cells (52.67%, P = 0.004). Down-regulation of CLIC1 led to the inhibition of invasion and migration by 54.31% (P = 0.000) and 33.62% (P = 0.001) in SGC-7901 and 40.74% (P = 0.000) and 29.26% (P = 0.002) in MGC-803. However, there was no significant difference between the mock group cells and the negative control group cells.CONCLUSION: High CLIC1 expression can efficiently inhibit proliferation and enhance apoptosis, migration and invasion of gastric cancer cells in vitro. CLIC1 might be a promising target for the treatment of gastric cancer.