THE ULTRASTRUCTURE OF SEPARATED AND CULTURED CELL OF PORPHYRA YEZOENSIS

There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monospores. But there are few investigations on the subcellular structure of the isolated vegetative cell for comparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, compared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formation, such as production of small and large fibrous vesicles, but was accompanied by vacuolation and starch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.

Alcohol Dehydrogenase Activity in Cultured Cells from Different Tobacco (Nicotiana tabacum L.) Varieties

The activity of alcohol dehydrogenase (ADH) in cultured cells of various tobacco was determined. It was found that significant differences existed in cells of different varieties cultured under normal conditions and as well after treated with exogenous ethanol. The ADH activity had positive relation with the ability of the cells to catabolize exogenous ethanol, indicating that the main function of the ADH in tobacco cells was in the direction of converting ethanol to acetaldehyde.

Sequential extraction of RNA,DNA and protein from cultured cells of the same group

BACKGROUND Efficient extraction of nucleic acids and proteins(ENAP)from cells is a prerequisite for precise annotation of gene function,and has become laboratory routine for revealing the mysteries of life.However,cell samples are often from different culture dishes,resulting in inevitable experimental errors and sometimes poor repeatability.AIM To explore a method to improve the efficiency of ENAP,minimizing errors in ENAP processes,enhancing the reliability and repeatability of subsequent experimental results.METHODS A protocol for the sequential isolation of RNA,DNA,and proteins from the same cultured HepG2 cells using RNAzol reagent is presented here.The first step involves culturing HepG2 cells to the exponential phase,followed by the sequential isolation of RNA,DNA,and proteins from the same cultured cells in the second step.The yield of nucleic acids and proteins is detected in the third step,and their purity and integrity are verified in the last step.RESULTS The procedure takes as few as 3-4 d from the start to quality verification and is highly efficient.In contrast to the existing kits and reagents,which are primarily based on independent isolation,this RNAzol reagent-based method is characterized by the sequential isolation of RNA,DNA,and proteins from the same cells,and therefore saves time,and has low cost and high efficiency.CONCLUSION The RNA,DNA,and proteins isolated using this method can be used for reverse transcription-polymerase chain reaction,polymerase chain reaction,and western blotting,respectively.

Current status and challenges for cell-cultured milk technology: a systematic review

Cellular agriculture is an innovative technology for manufacturing sustainable agricultural products as an alternative to traditional agriculture.While most cellular agriculture is predominantly centered on the production of cultured meat,there is a growing demand for an understanding of the production techniques involved in dairy products within cellular agriculture.This review focuses on the current status of cellular agriculture in the dairy sector and technical challenges for cell-cultured milk production.Cellular agriculture technology in the dairy sector has been classified into fermentation-based and animal cell culture-based cellular agriculture.Currently,various companies synthesize milk components through precision fermentation technology.Nevertheless,several startup companies are pursuing animal cell-based technology,driven by public concerns regarding genetically modified organisms in precision fermentation technology.Hence,this review offers an up-to-date exploration of animal cell-based cellular agriculture to produce milk components,specifically emphasizing the structural,functional,and productive aspects of mammary epithelial cells,providing new information for industry and academia.

Three-dimensional models:from cell culture to Patient-Derived Organoid and its application to future liposarcoma research

Liposarcoma is one of the most common soft tissue sarcomas,however,its occurrence rate is still rare compared to other cancers.Due to its rarity,in vitro experiments are an essential approach to elucidate liposarcoma pathobiology.Conventional cell culture-based research(2D cell culture)is still playing a pivotal role,while several shortcomings have been recently under discussion.In vivo,mouse models are usually adopted for pre-clinical analyses with expectations to overcome the issues of 2D cell culture.However,they do not fully recapitulate human dedifferentiated liposarcoma(DDLPS)characteristics.Therefore,three-dimensional(3D)culture systems have been the recent research focus in the cell biology field with the expectation to overcome at the same time the disadvantages of 2D cell culture and in vivo animal models and fill in the gap between them.Given the liposarcoma rarity,we believe that 3D cell culture techniques,including 3D cell cultures/co-cultures,and Patient-Derived tumor Organoids(PDOs),represent a promising approach to facilitate liposarcoma investigation and elucidate its molecular mechanisms and effective therapy development.In this review,we first provide a general overview of 3D cell cultures compared to 2D cell cultures.We then focus on one of the recent 3D cell culture applications,Patient-Derived Organoids(PDOs),summarizing and discussing several PDO methodologies.Finally,we discuss the current and future applications of PDOs to sarcoma,particularly in the field of liposarcoma.

In silico analysis of lncRNA-miRNA-mRNA signatures related to Sorafenib effectiveness in liver cancer cells

BACKGROUND Hepatocellular carcinoma(HCC)is the most common subtype of primary liver cancer with varied incidence and epidemiology worldwide.Sorafenib is still a recommended treatment for a large proportion of patients with advanced HCC.Different patterns of treatment responsiveness have been identified in differentiated hepatoblastoma HepG2 cells and metastatic HCC SNU449 cells.AIM To define the long non-codingRNA-microRNA-mRNA(lncRNA-miRNA-mRNA)predicted signatures related to selected hallmarks of cancer(apoptosis,autophagy,cell stress,cell dedifferentiation and invasiveness)in RNAseq studies using Sorafenib-treated HepG2 and SNU449 cells.Various available software analyses allowed us to establish the lncRNA-miRNA-mRNA regulatory axes following treatment in HepG2 and SNU449 cells.METHODS HepG2 and SNU449 cells were treated with Sorafenib(10μmol/L)for 24 hours.Total RNA,including small and long RNA,was extracted with a commercial miRNeasy kit.RNAseq was carried out for the identification of changes in lncRNA-miRNA-mRNA regulatory axes.RESULTS MALAT,THAP9-AS1 and SNGH17 appeared to coordinately regulate miR-374b-3p and miR-769-5p that led to upregulation of SMAD7,TIRARP,TFAP4 and FAXDC2 in HepG2 cells.SNHG12,EPB41 L4A-AS1,LINC01578,SNHG12 and GAS5 interacted with let-7b-3p,miR-195-5p and VEGFA in SNU449 cells.The axes MALAT1/hsamir-374b-3p/SMAD7 and MALAT1/hsa-mir-769-5p/TFAP4 were of high relevance for Sorafenib response in HepG2 cells,whereas PVT1/hsa-miR-195-5p/VEGFA was responsible for the differential response of SNU449 cells to Sorafenib treatment.CONCLUSION Critical lncRNAs acting as sponges of miRNA were identified that regulated mRNA expression,whose proteins mainly increased the antitumor effectiveness of the treatment(SMAD7,TIRARP,TFAP4,FAXDC2 and ADRB2).However,the broad regulatory axis leading to increased VEGFA expression may be related to the side effect of Sorafenib in SNU449 cells.

Efficacy of serum-free cultured human umbilical cord mesenchymal stem cells in the treatment of knee osteoarthritis in mice

BACKGROUND We investigated the efficacy of intra-articular injection of human umbilical cord mesenchymal stem cells(hUC-MSCs)for the treatment of osteoarthritis(OA)progression in the knee joint.Although many experimental studies of hUC-MSCs have been published,these studies have mainly used fetal bovine serumcontaining cultures of hUC-MSCs;serum-free cultures generally avoid the shortcomings of serum-containing cultures and are not subject to ethical limitations,have a wide range of prospects for clinical application,and provide a basis or animal experimentation for clinical experiments.AIM To study the therapeutic effects of serum-free hUC-MSCs(N-hUCMSCs)in a mouse model of knee OA.METHODS Fifty-five male C57BL/6 mice were randomly divided into six groups:The blank control group,model control group,serum-containing hUC-MSCs(S-hUCMSC)group,N-hUCMSC group and hyaluronic acid(HA)group.After 9 weeks of modeling,the serum levels of interleukin(IL)-1β and IL-1 were determined.Hematoxylin-eosin staining was used to observe the cartilage tissue,and the Mankin score was determined.Immunohistochemistry and western blotting were used to determine the expression of collagen type II,matrix metalloproteinase(MMP)-1 and MMP-13.RESULTS The Mankin score and serum IL-1 and IL-1β and cartilage tissue MMP-1 and MMP-13 expression were significantly greater in the experimental group than in the blank control group(P<0.05).Collagen II expression in the experimental group was significantly lower than that in the blank control group(P<0.05).The Mankin score and serum IL-1 and IL-1β and cartilage tissue MMP-1 and MMP-13 levels the experimental group were lower than those in the model control group(P<0.05).Collagen II expression in the experimental group was significantly greater than that in the model control group(P<0.05).CONCLUSION N-hUCMSC treatment significantly alleviate the pathological damage caused by OA.The treatment effects of the ShUCMSC group and HA group were similar.

A new polyphenol, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, isolated from cultured cells of Saussurea involucrata

The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl(DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1–5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.

Actomyosin is Involved in the Organization of the Microtubule Preprophase Band in Arabidopsis Suspension Cultured Cells

The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organization of PPBs in Arabidopsis suspension cultured cells was investigated by confocal laser scanning microscopy combined with pharmacological treatments of reagents specific for the cytoskeleton elements. Double staining of F-actin and microtubules （MTs） showed that actin filaments were arranged randomly and no colocalization with cortical MTs was observed in the interphase cells. However, cortical actin filaments showed colocalization with MTs during the formation of PPBs. A broad actin band formed with the broad MT band in the initiation of PPB and narrowed down together with the MT band to form the PPB. Nevertheless, broad MT bands were formed but failed to narrow down in cells treated with the F-actin disruptor latrunculin A. In contrast, in the presence of the F-actin stabilizer phalloidin, PPB formation did not exhibit any abnormality. Therefore, the integrity, but not the dynamics, of the actin cytoskeleton is necessary for the formation of normal PPBs. Treatment with 2, 3-butanedine monoxime, a myosin inhibitor, also resulted in the formation of broad MT bands, indicating that actomyosin may be involved in the rearrangement of MTs to form the PPBs. Double staining of MTs and myosin revealed that myosin concentrated on the PPB region during PPB formation. It is suggested that the actin cytoskeleton at the PPB site may serve as a rack to transport cortical MTs by using myosin when the broad MT band narrows down to form the PPB.

Antagonistic Effects of Tranilast on Proliferation and Collagen Synthesis Induced by TGF-β_2 in Cultured Human Trabecular Meshwork Cells

Whether tranilast had antagonistic effect on proliferation inhibition and collagen synthesis promotion induced by TGF-β 2 in cultured human trabecular meshwork cells was investigated. Suspension of 1×104 cultured human trabecular meshwork cells of 3—5 passage was distributed in each well of a 96-well disk and divided into control group and experimental group. After 24 h, 0 μg/ml (control), 12.5 μg/ml, 25 μg/ml, 50 μg/ml tranilast with 3.2 ng/ml TGF-β 2 were added into the incubation medium. Another 24 h later, proliferation and collagen synthesis in cultured human trabecular meshwork cells were examined respectively by using tetrazolium-based semiautomated colormetric (MTT) assay and 3H-proline incorporation with liquid scintillation technique. The results showed absorbance (A) values of the experimental groups were 0.9036±0.3017, 1.1361± 0.1352, 1.2457±0.1524 according to the different concentrations of tranilast, and 0.8956± 0.1903 of the control group. In comparison with the control group, 25 μg/ml (q'=3.23, P< 0.05), 50 μg/ml (q'=4.70, P<0.01) tranilast significantly antagonized the decrease of the A values induced by TGF-β 2 in the cultured human trabecular meshwork cells. In comparison with the control group [817.37±124.21 cpm/104 cells], 12.5 μg/ml (620.33±80.46 cpm/104 cells, q'= 4.26, P< 0.05), 25 μg/ml (594.58±88.13 cpm/104 cells, q'=4.81, P<0.01), 50 μg/ml (418.64±67.90 cpm/104 cells, q'=8.62, P<0.01) tranilast significantly inhibited the incorporation of 3H-proline into the cultured human trabecular meshwork cells promoted by TGF-β 2 in a dose-dependent manner. It was concluded that tranilast had the antagonistic effect on the proliferation inhibition and collagen synthesis promotion induced by TGF-β 2 in the cultured human trabecular meshwork cells.

Effect of Transforming Growth Factor-β_2 on Phagocytosis in Cultured Bovine Trabecular Meshwork Cells

The effect of transforming growth factor β 2 (TGF β 2) on phagocytosis in bovine trabecular meshwork cells in vitro was investigated. After the cultured bovine trabecular meshwork cells were treated with 0 ng/ml, 0.32 ng/ml, 1 ng/ml, 3.2 ng/ml TGF β 2 for 24 h, latex beads were added into the incubation medium, and the numbers of the latex beads in 20 adjacent cells were counted under a microscope 24 h later, after treatment with Wright's stain. Our results showed that the average numbers of the latex beads in the trabecular meshwork cells treated with TGF β 2 of different concentrations were 53.1±1.7 beads/cell, 56.4±2.9 beads/cell and 77.9±6.5 beads/cell respectinvely, in comparison with 45.5±3.3 beads/cell of the control group. TGF β 2 significantly increased the number of the latex beads phagocytosed by cultured bovine trabecular meshwork cells in a dose dependent manner. TGF β 2 could promote the phagocytosis of bovine trabecular meshwork cells in vitro . It may be involved in the cellularity decrease of the trabecular meshwork in the patients of primary open angle glaucoma through promoting the phagocytosis of trabecular meshwork cells.

METABOLISM -OF LOW DENSITY LIPOPROTEIN-DEPENDENT UNSATURATED FATTY ACID IN CULTURED CELLS

The traditional view of the regulation of eicosanoid formation holds that agonists have to activate receptor-coupled phospholipases before eicosanoid syntheiss can be initiated. Action of phospholipases results in an increase in the intracellular concentration of unesterified arachidonic acid (AA). Once unesterified AA is present in sufficient amounts it can be metabolized by a variety of enzymes that catalyze

Expression of Inositol 1,4,5-trisphosphate Receptor mRNA in Myocardium of Spontaneous Hypertension Rats and Cultured Vascular Smooth Muscle Cells of Rats

Objective\ To investigate expression of inositol 1,4,5 trisphosphate receptor (IP\-3R) mRNA on sacroplasmic reticular in myocardium of spontaneous hypertension rats (SHRs) and cultured vascular smooth muscle cells (VSMC) of rats and effects of perindopril and urapidil on them. Methods\ SHRs were orally given perindopril (1.0 mg·kg\+\{ 1\}·d\+\{ 1\}) or urapidil (15 mg·kg\+\{ 1\}·d\+\{ 1\}) for 24 weeks, respectively. Expression of IP\-3R mRNA was examined by semi quantitative reverse transcription polymers chain reaction (RT PCR) using three oligonuclotide primers for each subtype of IP\-3R with β actin as internal label. Results\ All subtypes of IP\-3R were expressed in myocardium of SHR, WKY and cultured VSMC. Expression of IP\-3R mRNA in left ventricle of SHR was markedly enhanced. Urapidil could down regulate expression of IP\-3R Ⅰand IP\-3R Ⅲ, perindopril slightly increased expression of IP\-3R Ⅱ and decreased expression of IP\-3R Ⅰand IP\-3R Ⅲ in myocardium of SHR. Conclusion\ Our results suggest that expression of IP\-3R mRNA in cardiovascular system could be regulated by urapidil and perindopril.

EFFECT OF QUERCETIN ON CULTURED HUMAN VASCULAR ENDOTHELIAL CELLS

Objective To study the effects of quercetin (Que) on the release of endothelin-1 (ET-1) and prostacylin(PGI2) by normal human vascuiar endothelial cell (VEC). Methods Radioimmunoassay(RIA) was used to assess the amount of ET-1 and PGI2 produced by VEC. VEC prollferation was assessed by tetrazolium(MTT) assay. Results Que increased the normal VEC prollferation at the concentration or 5, 2o, 4o, 8o, 1oompol/L and increased the production of PG12 and inhibits the release of ET by the normal VEC at the concentratiou or 5, 2o and 8ompol/L. Que at the concentration of 5, 2o and 8omol/L had no direct effect on morphology of the normal VEC. ConcIusion Que can stimulate the proliferation of VEC and inhibit tbe reIease of ET-1 and increase the formation of PGI2. The data suggest that Que might be beneficial for the prevention and treatment of vascular endothelial injury-related cardiovascular diseases, such as atherosclerosls and thromboembolism diseases.

Biological Characteristics of Human Bone Marrow Mesenchymal Stem Cell Cultured in Vitro

Some biological characteristics of human bone marrow mesenchymal stem cells (MSCs) cultured in vitro were observed. hMSCs were isolated from bone marrow and purified by density gradient centrifugation method, and then cultured in vitro. The proliferation and growth characteristics of hMSCs were observed in primary and passage culture. MSCs of passage 3 were examined for the purify by positive rate of CD29 and CD44 through flow cytometry. Human bone marrow MSCs showed active proliferation capacity in vitro. The purify of MSCs separated by our method was higher than 90 %. It was concluded that hMSCs have been successfully cultured and expanded effectively. It provided a foundation for further investigation and application of MSCs.

An Efficient Rice Mutagenesis System Based on Suspension-Cultured Cells

Plant mutants are important bio-resources for crop breeding and gene functional studies. Conventional methods for generating mutant libraries by mutagenesis of seeds with physical or chemical agents are of low efficiency. Here, we developed a highly-efficient ethyl methanesulfonate （EMS） mutagenesis system based on suspension-cultured cells, with rice （Oryza sativa L.） as an example. We show that treatment of suspension-cultured tiny cell clusters with 0.4% EMS for 18-22 h followed by differentiation and regeneration produced as high as 29.4% independent mutant lines with visible phenotypic variations, including a number of important agronomic traits such as grain size, panicle size, grain or panicle shape, tiller number and angle, heading date, male sterility, and disease sensitivity. No mosaic mutant was observed in the mutant lines tested. In this mutant library, we obtained a mutant with an abnormally elongated uppermost internode. Sequencing and functional analysis revealed that this is a new allelic mutant of eui （elongated uppermost internode） caused by two point mutations in the first exon of the EUI gene, representing a successful example of this mutagenesis system.

Expression of Transforming Growth Factor-β in Cultured Normal Human Lens Epithelia Cells

Summary: In order to investigate whether cultured normal human lens epithelial cells (LEC) express transforming growth factor β (TGF-β), reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical methods were used for detection of TGF-β mRNA and protein in cultured normal human LEC. The results showed that a single RT-PCR amplified product about 310bp was obtained, and the sequence was homologous to the known sequence. TGF-β immunostain was positive in the plasma of LEC. It was suggested that normal human LEC could produce TGF-β, and LEC could be affected by TGF-β through autocrine action.

Transplantation of primary cultured embryonic mesencephalic neural precursor cells for treating Parkinsonian rats

BACKGROUND： Choosing proper donor cells is one of keys in experimental and clinical studies on cell replacement therapy （CRT） for treating Parkinson disease （PD）. Embryonic mesencephalic precursor cells （MPCs） can stably differentiate into dopaminergic neuron after in vitro proliferated culture. As compared with embryonic stem cell and neural stem cell strains, cell composition of embryonic MPCs after primary culture is also the most close to that of embryonic mesencephalic ventral cell suspension without proliferated culture. Successful experience accumulated in the latter suggests that primary cultured embryonic MPCs might be the most potential donor cells in clinical application with CRT for treating PD so far. OBJECTIVE： To investigate the feasibility of primary cultured embryonic precursor cells cultured primarily as donor cells in CRT for treating PD in rats. DESIGN ： A randomized and controlled trial taking SD rats as experimental animals.SETTING： Department of Neurosurgery, Huashan Hospital Affiliated to Fudan University.MATERIALS： This experiment was carried out at the Institute of Neuroscience, Shanghai Institute for Biological Science, Chinese Academy of Sciences from July 2003 to June 2004. Totally 26 female SD rats, with body mass of 200 to 220 g, were provided by Shanghai Experimental Animal Center of Chinese Academy of Sciences. METHODS ： Stereotaxic injection of 6-hydroxydopamine into the medial forebrain bundle were perfored to develop PD model rat. Among 26 SD rats, 20 rats achieved a more than 5 turns/min in apomorphine induced rotation test, reaching the standard of PD model rats. Immunohistochemical detection was performed on 1 out of 20 model rats after execution, and the other 19 rats were randomly divided into control group （n=5）, sham transplantation group （n=5）and cell grafted group （n=9）. Primary cultured E12 MPC cell suspension （1.2×10^11 L^-1）were used as donor cells. 4μL primary cultured E12 MPC cell suspension prepared freshly was injected into the lesioned corpus striatum of rats in cell grafted group, and 4μL D-Hank＇s solution was injected in sham transplantation group in the same way. There was no injection in control group. Apomorphine-induced rotation rate of PD rats were recorded respectively in cell grafted group and sham transplantation group pre-operation （initial value） and at postoperative 2, 4, 6 and 16 weeks. Apomorphine-induced rotation rate of PD rats was recorded in control group at postoperative 2 months （initial value） and following 2,4,6 and 16 weeks. To determine TH antigen with immunohistological ABC method （DAB developing） at 6 months post-transplantation to investigate the differentiation and survival of donor cells in the host body.MAIN OUTCOME MEASURES： Apomorphine-induced rotation behavior before and after transplantation and the survival and differentiation of implanted cells in the host body at 6 months post-transplantation. RESULTS： Among 19 model rats, one rat died after transplantation respectively in the cell grafted group and sham transplantation group; finally 17 model rats entered the stage of result analysis. Relative apomorphine-induced rotation rate was significantly decreased in the cell grafted group as compared with that before transplantation , with significant difference （P 〈 0.01 .P 〈 0.05）;the mean value of relative apomorphine-induced rotation rate was significantly decreased at postoperative 16 weeks in cell grafted group as compared with that of corresponding relative rotation rate in control group , also with significant difference （P 〈 0.05）.Immunohistological results showed that donor cells could differentiate into large and multi-polar dopaminergic neurons in the host body. CONCLUSION ： Primary cultured embryonic MPCs can be used as the donor cells in CRT for treating PD.

Isolation of Cultured Endothelial Progenitor Cells in vitro from PBMCs and CD133^+ Enriched Cells

Two isolation methods for sorting of endothelial progenitor cells(EPCs):from peripheral blood mononuclear cells(PBMCs)and CD133+ enriched cells were compared,by defining the cell morphology,phenotype,reproductive activities and function in vitro,to provide a reference for clinical application of EPCs.PBMCs from healthy subjects were used either directly for cell culture or for CD133+ sorting.The two groups of cells were cultured in complete medium 199(M199)for 7 to 14 days and the phenotypes of EPCs were an...

Hexabromocyclododecane-induced Genotoxicity in Cultured Human Breast Cells through DNA Damage

To investigate the genotoxicity and reveal the potential toxicological mechanisms of Hexabromocyclododecane （HBCD）, human breast cells HBL-100 were exposed to a sequence of HBCD concentrations （0, 5, 10, and 50 mg/L） for 24 h. With a series of zymology and molecular biology methods, we found that HBCD induced dose-dependent oxidative stress on HBL-100 DNA. As revealed in q RT-PCR, activated prognostic factor ATM down-regulated tumor suppressor gene BRCA1 and prompted DNA repair genes h OGG1 and h MTH1 expression in lower concentrations of HBCD （〈 10 mg/L）. However, DNA repair were inhibited as well as cell proliferation rate by higher concentrations of HBCD （50 mg/L）. The results inferred that the genotoxicity of HBCD was dose-dependent and related to DNA repair pathway.