SEARCH · Search PubMed

Results for “HEK293 Cells”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed2005

Functional properties of endogenous receptor- and store-operated calcium influx channels in HEK293 cells.

Activation of phospholipase C (PLC)-mediated signaling pathways in non-excitable cells causes the release of calcium (Ca2+) from inositol 1,4,5-trisphosphate (InsP3)-sensitive intracellular Ca2+ stores and activation of Ca2+ influx via plasma membrane Ca2+ channels. The properties and molecular identity of plasma membrane Ca2+ influx channels in non-excitable cells is a focus of intense investigation. In the previous studies we used patch clamp electrophysiology to describe the properties of Ca2+ influx channels in human carcinoma A431 cell lines. Now we extend our studies to human embryonic kidney HEK293 cells. By using a combination of Ca2+ imaging and whole cell and single channel patch clamp recordings we discovered that: 1) HEK293 cells contain four types of plasma membrane Ca2+ influx channels: I(CRAC), Imin, Imax, and I(NS); 2) I(CRAC) channels are highly Ca2+-selective (P(Ca/Cs)>1000) and I(CRAC) single channel conductance is too small for single channel analysis; 3) Imin channels in HEK293 cells display functional properties identical to Imin channels in A431 cells, with single channel conductance of 1.2 pS for divalent cations, 10 pS for monovalent cations, and divalent cation selectivity P(Ba/K)=20; 4) Imin channels in HEK293 cells are activated by InsP3 and inhibited by phosphatidylinositol 4,5-bisphosphate, but store-independent; 5) when compared with Imin, Imax channels have higher conductance for divalent (17 pS) and monovalent (33 pS) cations, but less selective for divalent cations (P(Ba/K)=4), 6) Imax channels in HEK293 cells can be activated by InsP3 or by Ca2+ store depletion; 7) I(NS) channels are non-selective (P(Ba/K)=0.4) and display a single channel conductance of 5 pS; and 8) I(NS) channels are not gated by InsP3 but activated by depletion of intracellular Ca2+ stores. Our findings provide novel information about endogenous Ca2+ channels supporting receptor-operated and store-operated Ca2+ influx pathways in HEK293 cells.

Calcium↗

PubMed1997

Comparison of ouabain-sensitive and -insensitive Na/K pumps in HEK293 cells.

The Na/K pump current I(p) of single HEK293 cells either untransfected (endogenous I(p)) or transfected with the alpha1 subunit of the rat Na/K pump (exogenous I(p)) was investigated in Na-containing solution by means of whole-cell recording at 30 degrees C. The endogenous I(p) was irreversibly blocked by 10(-4) M ouabain or 2 x 10(-4) M dihydro-ouabain (DHO). Its density amounted to 0.33 pA pF(-1) at 0 mV and 5.4 mM K(o). It was half maximally activated at 1.5 mM K(o) and increased linearly with depolarization over the entire voltage range studied (-80 to +60 mV). In contrast, HEK293 cells stably transfected with cDNA for the cardiac glycoside-resistant alpha1 subunit of the rat Na/K pump showed an I(p) in the presence of 10(-4) M ouabain and 2 x 10(-4) M DHO, respectively. This exogenous I(p) was reversibly blocked by 10(-2) M ouabain. Half maximal activation of the exogenous I(p) occurred at 1.7 mM K(o). Its amplitude increased linearly with depolarization at negative voltages but remained almost constant at positive membrane potentials. Comparison with the I(p) of isolated rat cardiac ventricular myocytes strongly suggests that the exogenous I(p) in HEK293 cells is generated by the alpha1 subunit of the rat Na/K pump since it displays identical properties. Therefore, HEK293 cells represent an expression system well suited for the electrophysiological analysis of recombinant, cardiac glycoside-resistant Na/K pumps by means of whole-cell recording.

Animals↗

PubMed2004

Reduction of adenovirus E1A mRNA by RNAi results in enhanced recombinant protein expression in transiently transfected HEK293 cells.

Human embryonic kidney 293 (HEK293) cells, a widely used host for large-scale transient expression of recombinant proteins, are transformed with the adenovirus E1A and E1B genes. Because the E1A proteins function as transcriptional activators or repressors, they may have a positive or negative effect on transient transgene expression in this cell line. Suspension cultures of HEK293 EBNA (HEK293E) cells were co-transfected with a reporter plasmid expressing the GFP gene and a plasmid expressing a short hairpin RNA (shRNA) targeting the E1A mRNAs for degradation by RNA interference (RNAi). The presence of the shRNA in HEK293E cells reduced the steady state level of E1A mRNA up to 75% and increased transient GFP expression from either the elongation factor-1alpha (EF-1alpha) promoter or the human cytomegalovirus (HCMV) immediate early promoter up to twofold. E1A mRNA depletion also resulted in a twofold increase in transient expression of a recombinant IgG in both small- and large-scale suspension cultures when the IgG light and heavy chain genes were controlled by the EF-1alpha promoter. Finally, transient IgG expression was enhanced 2.5-fold when the anti-E1A shRNA was expressed from the same vector as the IgG light chain gene. These results demonstrated that E1A has a negative effect on transient gene expression in HEK293E cells, and they established that RNAi can be used to enhance recombinant protein expression in mammalian cells.

Adenovirus E1A Proteins↗

PubMed1997

Stable expression of the human large-conductance Ca2+-activated K+ channel alpha- and beta-subunits in HEK293 cells.

We have generated HEK293 cell lines stably expressing high levels of either the human BK channel alpha-subunit alone or the BK channel alpha-subunit and beta-subunit together. For co-expression a plasmid with three expression cassettes was constructed. Patch-clamp recordings on inside-out patches from the transfected cells resulted in macroscopic currents reflecting the expression of 200-800 BK channels per patch. No decrease in channel expression could be detected in cells grown for more than 50 passages. The alpha-subunit when expressed alone conducted currents which were sensitive to intracellular Ca2+ in the physiological range. In the presence of the beta-subunit the steady-state activation curves were shifted by -20 to -30 mV and channel deactivation kinetics were slowed. The BK channel opener NS1608 (10 microM) shifted the steady-state activation curves for the alpha-subunit as well as for the alphabeta-subunits by -40 to -50 mV.

Calcium↗

PubMed1998

Characterization of human recombinant neuronal nicotinic acetylcholine receptor subunit combinations alpha2beta4, alpha3beta4 and alpha4beta4 stably expressed in HEK293 cells.

Human embryonic kidney (HEK293) cells were transfected with cDNA encoding the human beta4 neuronal nicotinic acetylcholine (ACh) receptor subunit in pairwise combination with human alpha2, alpha3 or alpha4 subunits. Cell lines A2B4, A3B4.2 and A4B4 were identified that stably express mRNA and protein corresponding to alpha2 and beta4, to alpha3 and beta4 and to alpha4 and beta4 subunits, respectively. Specific binding of [3H]epibatidine was detected in A2B4, A3B4.2 and A4B4 cells with Kd (mean +/- S.D. in pM) values of 42 +/- 10, 230 +/- 12 and 187 +/- 29 and with Bmax (fmol/mg protein) values of 1104 +/- 338, 2010 +/- 184 and 3683 +/- 1450, respectively. Whole-cell patch-clamp recordings in each cell line demonstrated that (-)nicotine (Nic), ACh, cytisine (Cyt) and 1, 1-dimethyl-4-phenylpiperazinium iodide (DMPP) elicit transient inward currents. The current-voltage (I-V) relation of these currents showed strong inward rectification. Pharmacological characterization of agonist-induced elevations of intracellular free Ca++ concentration revealed a distinct rank order of agonist potency for each subunit combination as follows: alpha2beta4, (+)epibatidine (Epi) > Cyt > suberyldicholine (Sub) = Nic = DMPP; alpha3beta4, Epi > DMPP = Cyt = Nic = Sub; alpha4beta4, Epi > Cyt = Sub > Nic > DMPP. The noncompetitive antagonists mecamylamine and d-tubocurarine did not display subtype selectivity. In contrast, the Kb value for the competitive antagonist dihydro-beta-erythroidine (DHbetaE) was highest at alpha3beta4 compared with alpha2beta4 or alpha4beta4 receptors. These data illustrate that the A2B4, A3B4.2 and A4B4 stable cell lines are powerful tools for examining the functional and pharmacological properties of human alpha2beta4, alpha3beta4 and alpha4beta4 neuronal nicotinic receptors.

Bridged Bicyclo Compounds, Heterocyclic↗

PubMed1996

Endogenous calcium channels in human embryonic kidney (HEK293) cells.

1. We have identified endogenous calcium channel currents in HEK293 cells. Whole cell endogenous currents (ISr-HEK) were studied in single HEK293 cells with 10 mM strontium as the charge carrier by the patch clamp technique. The kinetic properties and pharmacological features of ISr-HEK were characterized and compared with the properties of a heterologously expressed chimeric L-type calcium channel construct. 2. ISr-HEK activated on depolarization to voltages positive of -40 mV. It had transient current kinetics with a time to peak of 16 +/- 1.4 ms (n = 7) and an inactivation times constant of 52 +/- 5 ms (n = 7) at a test potential of 0 mV. The voltage for half maximal activation was -19.0 +/- 1.5 mV (n = 7) and the voltage for half maximal steady-state inactivation was -39.7 +/- 2.3 mV (n = 7). 3. Block of ISr-HEK by the dihydropyridine isradipine was not stereoselective; 1 microM (+) and (-)-isradipine inhibited the current by 30 +/- 4% (n = 3) and 29 +/- 2% (n = 4) respectively. (+)-Isradipine and (-)-isradipine (10 microM) inhibited ISr-HEK by 89 +/- 4% (n = 5) and 88 +/- 8% (n = 3) respectively. The 7-bromo substituted (+/-)-isradipine (VO2605, 10 microM) which is almost inactive on L-type calcium channels also inhibited ISr-HEK (83 +/- 9%, n = 3) as was observed for 10 microM (-)-nimodipine (78 +/- 6%, n = 5). Interestingly, 10 microM (+/-)-Bay K 8644 (n = 5) had no effect on the current. ISr-HEK was only slightly inhibited by the cone snail toxins omega-CTx GVIA (1 microM, inhibition by 17 +/- 3%, n = 4) and omega-CTx MVIIC (1 microM, inhibition by 20 +/- 3%, n = 4). The funnel web spider toxin omega-Aga IVA (200 nM) inhibited ISr-HEK by 19 +/- 2%, n = 4). 4. In cells expressing ISr-HEK, maximum inward current densities of 0.24 +/- 0.03 pA/pF and 0.39 +/- 0.7 pA/ pF (at a test potential of -10 mV) were estimated in two different batches of HEK293 cells. The current density increased to 0.88 +/- 0.18 pA/pF or 1.11 +/- 0.2 pA/pF respectively, if the cells were cultured for 4 days in serum-free medium. 5. Co-expression of a chimeric L-type calcium channel construct revealed that ISr-HEK and L-type calcium channel currents could be distinguished by their different voltage-dependencies and current kinetics. The current density after heterologous expression of the L-type alpha 1 subunit chimera was estimated to be about ten times higher in serum containing medium (2.14 +/- 0.45 pA/pF) than that of ISr-HEK under the same conditions.

Calcium Channels↗

PubMed2006

Human Nogo-C overexpression induces HEK293 cell apoptosis via a mechanism that involves JNK-c-Jun pathway.

The neurite outgrowth inhibitor protein Nogo-A has been identified as an inhibitor of axonal regeneration, and Nogo-B as a regulator of vasculature remodeling, but the additional roles of Nogo isoforms, especially Nogo-C, have obtained little attention. Nogo-C is weakly expressed in liver and kidney compared to the high expression in skeletal muscle. Here we detected the weak expression of Nogo-C in human embryonic kidney cell line HEK293, and found that Nogo-C expressed in HEK293 could induce cell apoptosis. Further experiments demonstrated the activation of JNK/SAPK and c-Jun, but not p38 in Nogo-C expressed cells. And JNK-specific inhibitor SP600125 could reduce cell apoptosis induced by Nogo-C. Furthermore, the activation of caspase-3 and PARP, the expression and phosphorylation of p53 were also detected. The data first revealed Nogo-C expressed in HEK293 confers apoptosis by inducing caspase-3 and p53 activation through the JNK-c-Jun-dependent pathway.

Apoptosis↗

PubMed2003

Characterization of cAMP accumulation mediated by three alpha1-adrenoceptor subtypes in HEK293 cells.

AIM: To investigate the characterization of cAMP response mediated by alpha1-adrenoceptor (alpha1-AR) subtypes in HEK293 cells. METHODS: (1) Full-length cDNA encoding three alpha1-AR subtypes were transfected into HEK293 cells by the calcium phosphate precipitation method, respectively. (2) The densities of alpha1-AR subtypes expressed in HEK293 cells were measured by radioligand binding assay. (3) cAMP accumulation was measured by [3H]adenine prelabeling method. RESULTS: (1) Activation of each of three subtypes resulted in an increase of cAMP accumulation in HEK293 cells in a dose-dependent manner, which was inhibited by selective alpha1-AR antagonist prazosin. (2) Comparing the pharmacological property, the maximal responses of alpha1A-AR to agonists were the most potent, while the sensitivity of alpha1-AR subtypes to norepinephrine (NE) was the highest. CONCLUSION: Each of three alpha1-AR subtypes can mediate cAMP accumulation in HEK293 cell line, and there are differences in pharmacological property.

Cell Line↗

PubMed2003

Specific detection of non-functional human P2X(7) receptors in HEK293 cells and B-lymphocytes.

P2X(7) receptor/channels mediate ATP-induced apoptosis in a range of cells including lymphocytes. HEK293 cells were transfected with wild-type human P2X(7) receptor or site-directed mutant constructs (K193A, K311A and E496A) known to be non-functional from measurements of barium/ethidium influx in the presence of ATP or 2',3'-O-(4-benzoylbenzoyl)-ATP. An antibody was designed against an epitope from a loop adjacent to the extracellular ATP site. The epitope was unavailable in cells expressing normal functional surface receptors. Non-functional surface receptors as well as intracellular receptors selectively bound the antibody. So did B-lymphocytes from chronic lymphocytic leukemia patients expressing non-functional (E496A) mutant receptor.

Adenosine Triphosphate↗

PubMed2005

Ca2+ participates in alpha1B-adrenoceptor-mediated cAMP response in HEK293 cells.

AIM: To investigate the alpha1B-adrenoceptor (alpha1B-AR)-mediated cAMP response and underlying mechanisms in HEK293 cells. METHODS: Full-length cDNA encoding alpha1B-AR was transfected into HEK293 cells using the calcium phosphate precipitation method, and alpha1B-AR expression and cAMP accumulation were determined by using the saturation radioligand binding assay and ion-exchange chromatography, respectively. RESULTS: Under agonist stimulation, alpha1B-AR mediated cAMP synthesis in HEK293 cells, and blockade by PLC-PKC or tyrosine kinase did not reduce cAMP accumulation induced by NE. Pretreatment with pertussis toxin (PTX) had little effect on basal cAMP accumulation as well as norepinephrine (NE)-stimulated cAMP accumulation. In addition, pretreatment with cholera toxin (CTX) neither mimicked nor blocked the effect induced by NE. The extracellular Ca2+ chelator egtazic acid (EGTA), nonselective Ca2+ channel blocker CdCl2 and calmodulin (CaM) inhibitor W-7 significantly reduced NE-induced cAMP accumulation from 1.59%+/-0.47% to 1.00%+/-0.31%, 0.78%+/-0.23%, and 0.90%+/-0.40%, respectively. CONCLUSION: By coupling with a PTX-insensitive G protein, alpha1BAR promotes Ca2+ influx via receptor-dependent Ca2+ channels, then Ca2+ is linked to CaM to form a Ca2+-CaM complex, which stimulates adenylyl cyclase (AC), thereby increasing the cAMP production in HEK293 cell lines.

Calcium↗

PubMed2000

Cell proliferation and Ca(2+)-calmodulin dependent protein kinase activation mediated by alpha 1A- and alpha 1B-adrenergic receptor in HEK293 cells.

AIM: To examine the ability of alpha 1-AR subtypes on proliferation and Ca(2+)-calmodulin dependent protein kinase (CCDPK, formerly called MAPK) activation in transfected human embryo kidney 293 (HEK293) cells. METHODS: pREP8/alpha 1A-AR, pREP4/alpha 1B-AR, and pREP9/alpha 1D-AR were transfected, respectively, into HEK293 cells by calcium phosphate precipitation. The expression of alpha 1-AR was detected by radioligand binding assays. DNA synthesis was measured by [3H]thymidine incorporation. CCDPK activity was determined by immunoprecipitation method and myelin basic protein was used as substrate. RESULTS: Three clonal HEK293 cell lines stably expressing alpha 1A- or alpha 1B- or alpha 1D-AR were chosen and characterized by radioligand binding assay with receptor densities of about 0.6 nmol.g-1. Treatment with norepinephrine (NE) in the presence of propranolol for 24 h increased DNA synthesis in HEK293/alpha 1A- or HEK293/alpha 1B-AR cells concentration-dependently, with EC50 values of 48.8 nmol.L-1 (95% confidence limits 9.7-246 nmol.L-1) and 8.4 nmol.L-1 (95% confidence limits 2.1-32.9 nmol.L-1), respectively. The increase of DNA synthesis induced by NE 10 mumol.L-1 was 201% +/- 28% and 269% +/- 44% of basal, and the activation of CCDPK was 171% +/- 84% and 292% +/- 92% of basal in HEK293/alpha 1A-AR and HEK293/alpha 1B-AR cells, respectively. Preincubation with prazosin completely abolished NE-induced CCDPK activation in HEK293/alpha 1A- and alpha 1B-AR cells. Those changes were not found in HEK293/alpha 1D-AR cells. CONCLUSION: The activation of alpha 1A- or alpha 1B-AR but not alpha 1D-AR induces cell proliferation.

Adrenergic alpha-Agonists↗

PubMed2003

Effects of cannabinoids on endogenous K+ and Ca2+ currents in HEK293 cells.

Effects of cannabinoids on endogenous potassium and calcium currents in HEK293 cells were studied using the whole-cell variant of the patch-clamp technique. The cannabinoid agonists WIN 55,212-2, methanandamide, and anandamide (1 microM) decreased the calcium current by 53.1 +/- 2.6, 47.5 +/- 1.2, and 38.8 +/- 3.1%, respectively, after transfection of human CB1 cannabinoid receptor (hCB1) cDNA into HEK293 cells. The delayed rectifier-like current was not changed after application of these agonists, but the inward rectifier was increased by 94.0 +/- 3.6, 83.7 +/- 5.1, and 63.0 +/- 2.5% after application of WIN 55,212-2, methanandamide, and anandamide, respectively. The effects of the cannabinoid antagonists (AM251, AM281, and AM630) on the inward rectifier and calcium currents were the opposite of those seen with cannabinoid agonists; thus, these compounds act as inverse agonists in this preparation. These results suggest that endogenous inward rectifier and calcium currents are modulated by cannabinoids in HEK293 cells, and that some expressed receptors may be constitutively active.

Arachidonic Acids↗

PubMed1995

Characteristics of a human N-type calcium channel expressed in HEK293 cells.

The human alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel was stably expressed in HEK293 cells producing a human brain N-type voltage-dependent calcium channel (VDCC). Whole cell voltage-clamp electrophysiology and fura-2 based microfluorimetry have been used to study its characteristics. Calcium currents (ICa) recorded in transfected HEK293 cells were activated at potentials more depolarized than -20 mV with peak currents occurring at approx + 10 mV in 5 mM extracellular CaCl2. ICa and associated rises in intracellular free calcium concentrations ([Ca2+]i) were sensitive to changes in both the [Ca2+]o and holding potential. Steady-state inactivation was half maximal at a holding potential of -60 mV. Ba2+ was a more effective charge carrier than Ca2+ through the alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel and combinations of both Ba2+ and Ca2+ as charge carriers resulted in the anomalous mole fraction effect. Ca2+ influx into transfected HEK293 cells was irreversibly inhibited by omega-conotoxin-GVIA (omega-CgTx-GVIA; 10 nM-1 microM) and omega-conotoxin-MVIIA; 100 nM-1 microM) whereas 1 microM) whereas no reductions were seen with agents which block P or L-type Ca2+ channels. The inorganic ions, gadolinium (Gd3+), cadmium (Cd2+) and nickel (Ni2+) reduced the ICa under voltage-clamp conditions in a concentration-dependent manner. The order of potency of the three ions was Gd3+ > Cd2+ > Ni2+. These experiments suggest that the cloned and expressed alpha 1B-1 alpha 2b beta 1-2 Ca2+ channel subunits form channels in HEK293 cells that exhibit properties consistent with the activity of the native-N-type VDCC previously described in neurons.

Cadmium↗

PubMed2006

Different gene expression profiles of AD293 and HEK293 cell lines that show contrasting susceptibility to apoptosis induced by overexpression of Bim L.

Bim is a pro-apoptotic member of the Bcl-2 protein family. Overexpression of Bim proved to be highly cytotoxic for diverse cells. The AD293 cell line is derived directly from the HEK293 cell line but has been transfected with a gene that can improve cell adherence. We found that there was almost no apoptosis seen in Bim L-transfected AD293 cells, but more than half of Bim L-transfected HEK293 cells underwent apoptosis. Suppression subtractive hybridization was used to detect the different gene expression profile between these two cell lines. In 192 sequenced positive clones, there were 30 clones repeating twice or more. Ten genes were selected for identification by semi-quantitative RT-PCR. The transcripts of two adhesion-related genes (actin and parvin) and two apoptosis-related genes (cyclin 2 and protein phosphatase 1G) were up-regulated in AD293 cells. These results suggest that the high expression of cell adhesion-related proteins might be responsible for the different apoptosis status after the transfection of Bim L. Our data provide candidate genes responsible for the different apoptosis sensitivity of these two cell lines. Further investigation on the differential expression profile between AD293 and HEK293 might improve our understanding of cell apoptosis mechanism.

Actins↗

PubMed2005

[Construction of eukaryotic expression vector for HPC2 and its expression in HEK293 cells].

OBJECTIVE: To construct the eukaryotic expression vector for HPC2 for expression in HEK293 cells. METHODS: HPC2 from pcDNA3/HPC2 were inserted into the flag-tagged vector pcDNA3-flag by subcloning method. The recombinant plasmid pcDNA3-flag/HPC2 was then transfected into HEK293 cells using a routine lipofectamine method. The cell lysate was used for Western blotting to examine the expression of the target protein. RESULTS AND CONCLUSION: Double restriction enzyme digestion and DNA sequencing indicated successful construction of the eukaryotic expression vector for HPC2 and the fusion protein was highly expressed in HEK293 cells, which provides an important basis for functional study of HPC2.

Cell Line↗

PubMed2005

Caffeine induced Ca2+ release and capacitative Ca2+ entry in human embryonic kidney (HEK293) cells.

The potential role of endogenous ryanodine receptor (RyR) in modulating Ca2+ handling in HEK293 cells is controversial. Using Fura2/AM, here we provide evidence that caffeine can induce Ca2+ release from inositol 1,4,5-trisphosphate receptor-sensitive stores and Ca2+ entry in early passage numbers of HEK293 cells, but not in late passage ones. Ryanodine blocks caffeine-mediated effect, whereas 4-chloro-m-cresol can mimic these effects. In contrast, an increase in cyclic AMP or activation of voltage-dependent Ca2+ channels does not induce detectable alteration in intracellular Ca2+. Importantly, immunoblotting and staining have revealed that endogenous RyR expression is more abundant in the early than in the late passage cells. Additionally, similar to carbachol, Ca2+ entry in response to caffeine is blocked by capacitative Ca2+ entry inhibitors. These results indicate that the endogenous RyR in HEK293 cells can function as Ca2+ release channels and mediate capacitative Ca2+ entry, but they may be reduced due to cell passage.

Animals↗

PubMed2006

[Effects of hydrodynamic on aggregates formation, growth and metabolism of HEK293 cells in suspension culture].

By using the size distribution of cell aggregates, viable cell density, cell viability, specific consumption rate of glucose (q(glc)), specific production rate of lactate (q(lac)) and lactate transform rate (Y(lac/glc)) as the evaluation indexes, the effects of hydrodynamic on aggregates formation, growth and metabolism of HEK293 cells in suspension culture were examined in 250mL spinner-flasks by setting the agitation rates at 25, 50, 75 and 100r/min, respectively. It was found that agitation plays an important role in HEK293 cell aggregates formation and cell aggregates size distribution. After 7d cultivation in spinner-flasks operated at 50r/min and 75r/min, the average diameter of HEK293 cell aggregates was 201 microm and 175 microm, respectively, with the fraction of aggregates larger than 225 microm less than 10%. The cell viability was kept above 90% with the metabolic indexes, including q(glc), q(lac) and Y(lac/glc) kept constant. These results demonstrated that hydrodynamic derived from the proper agitation play a decisive role in controlling the formation and size distribution of HEK293 cell aggregates, and provided sufficient mass transfer to support the normal growth and metabolism of HEK293 cells in suspended aggregates.

Bioreactors↗

PubMed2005

[Interleukin-6 is involved in the enhanced proliferation of HEK293 cells by the tumor specific antigen of HCA520].

OBJECTIVE: To investigate the effect of tumor specific antigen of HCA520 on the proliferation of HEK293 cells and to obtain some functional implications for HCA520. METHODS: MTT assay was performed with HEK293 stable cell lines transfected with pcDNA3-HCA520-flag construct. Cytokines probably involved in HCA520 enhanced proliferation were screened by RT-PCR, and effect of these cytokines on the HEK293 cell proliferation was further confirmed by MTT assay. RESULTS: HCA520 significantly promoted the proliferation of HEK293 cells, which was at least partially attributed to the up-regulation of IL-6 in HEK293 cells by HCA520. CONCLUSION: HCA520 might accelerate tumorigenesis by promoting proliferation of cancerous cells.

Calcium-Binding Proteins↗