改进《大学物理实验》预习教学方式

预习教学是指导学生自主学习实验技能,理解实验原理的重要一环。目前,多数学校现行的预习教学侧重于机械地讲解实验操作步骤,教学方式多为要求抄写实验指导书,教学实际效果较差,教师和学生付出许多时间却收获甚微。文中主要通过分析现有预习教学方式的问题,提出预习内容分层次,分阶段进行的概念。实际教学实验验证了此种教学方式的可行性及相应效果。

Two Modes of Cytoklnesis in the Generative Cells of Amaryllis

The cytokinesis process of generative cells in Amaryllis vitiata Ait. wasexamined with electron microscopy. Investigation of 14 pollen tubes showed that 70percent of the generative cells were divided by a cell plate, while the other, 30 percentshowed a cleavage furrow which occurred at the position where a cell plate should takeplace. The cell plate appeared at First as a subunit in late anaphase, which was assembledin the midzone of the phragmoplast and coalesced as one large continued unit in telophase.On the other hand, just in anaphase, as two identical chromosome masses were segregatedfrom each other, the plasma membrane of the generative cell were furrowing inside fromthe tWo sides in the interzonal region. In some instances, the cell was almost divided intotwo parts by the constriction furrow. The occurrence of cleavage seemed to be associatedwith the re-establishment of the nuclear envelope and the disorder of microtubular arrays,as well as the unusual behavior of the chromosomes.

Highly efficient differentiation of human ES cells and iPS cells into mature pancreatic insulin-producing cells

Human pluripotent stem cells represent a potentially unlimited source of functional pancreatic endocrine lineage cells. Here we report a highly efficient approach to induce human embryonic stem （ES） cells and induced pluripo- tent stem （iPS） cells to differentiate into mature insulin-producing cells in a chemical-defined culture system. The differentiated human ES cells obtained by this approach comprised nearly 25% insulin-positive cells as assayed by flow cytometry analysis, which released insulin/C-peptide in response to glucose stimuli in a manner comparable to that of adult human islets. Most of these insulin-producing cells co-expressed mature β cell-specific markers such as NKX6-1 and PDX1, indicating a similar gene expression pattern to adult islet β cells in vivo. In this study, we also demonstrated that EGF facilitates the expansion of PDXl-positive pancreatic progenitors. Moreover, our protocol also succeeded in efficiently inducing human iPS cells to differentiate into insuIin-producing ceils. Therefore, this work not only provides a new model to study the mechanism of human pancreatic specialization and maturation in vitro, but also enhances the possibility of utilizing patient-specific iPS cells for the treatment of diabetes.

On an Extension and a Refinement of Van der Corput's Inequality

By introducing a parameter α, we give an extension of Van der Corput＇s inequality. Also a new strengthened version of it is considered.

LY294002 potentiates the anti-cancer effect of oxaliplatin for gastric cancer via death receptor pathway

AIM:To examine the effects of combined treatment of oxaliplatin and phosphatidylinositol 3'-kinase inhibitor,2-(4-morpholinyl) -8-phenyl-4H-1-benzopyran-4-one(LY294002) for gastric cancer. METHODS:Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay.Apoptotic cells were detected by flow cytometric analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay.Western blotting and immuno-precipitation were used to examine protein expression and recruitment,respectively.Nuclear factorκB(NFκB) binding activities were investigated using electrophoretic mobility shift assay.Nude mice were used to investigate tumor growth. RESULTS:Treatment with combined oxaliplatin and LY294002 resulted in increased cell growth inhibi-tion and cell apoptosis in vitro,and increased tumor growth inhibition and cell death in the tumor mass in vivo.In MKN45 and AGS cells,oxaliplatin treatment promoted both protein kinase B(Akt) and NFκB activation,while pretreatment with LY294002 significantly attenuated oxaliplatin-induced Akt activity and NFκB binding.LY294002 promoted oxaliplatin-induced Fas ligand(FasL) expression,Fas-associated death domain protein recruitment,caspase-8,Bid,and caspase-3 activation,and the short form of cellular caspase-8/FLICEinhibitory protein(c-FLIPS) inhibition.In vivo,LY294002 inhibited oxaliplatin-induced activation of Akt and NFκB,and increased oxaliplatin-induced expression of FasL,inhibition of c-FLIPS,and activation of caspase-8,Bid,and caspase-3. CONCLUSION:Combination of oxaliplatin and LY294002 was therapeutically promising for gastric cancer treatment.The enhanced sensitivity of the combined treatment was associated with the activation of the death receptor pathway.

Heterogeneity and plasticity of T helper cells

CD4 T helper （Th） cells play critical roles in adaptive immune responses. They recruit and activate other immune cells including B cells, CD8 T cells, macrophages, mast cells, neutrophils, eosinophils and basophils. Based on their functions, their pattern of cytokine secretion and their expression of specific transcription factors, Th cells, differentiated from naive CD4 T cells, are classified into four major lineages, Thl, Th2, Th17 and T regulatory （Treg） cells, although other Th lineages may exist. Subsets of the same lineage may express different effector cytokines, reside at different locations or give rise to cells with different fates, whereas cells from different lineages may secrete common cytokines, such as IL-2, IL-9 and IL-10, resulting in massive heterogeneity of the Th cell population. In addition, the pattern of cytokine secretion may switch from that of one lineage toward another under certain circumstances, suggesting that Th cells are plastic. Tregs are also more heterogeneous and plastic than were originally thought. In this review, we summarize recent reports on heterogeneity and plasticity of Th cells, and discuss potential mechanisms and implications of such features that Th cells display.

Exogenous phosphatidylethanolamine induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway

AIM: To investigate the signaling pathways implicated in phosphatidylethanolamine (PE)-induced apoptosis of human hepatoma HepG2 cells. METHODS: Inhibitory effects of PE on human hepatoma HepG2 cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle, apoptosis and mitochondrial transmembrane potential (ΔΨm) were analyzed by flow cytometry. Immunocytochemical assay and Western blotting were used to examine Bcl-2, Bax and caspase-3 protein levels in HepG2 cells treated with PE. RESULTS: PE inhibited the growth of HepG2 cells in a doseand timedependent manner. It did notaffect the cell cycle, but induced apoptosis. PE significantly decreased ΔΨm at 0.25, 0.5 and 1 mmol/L, respectively, suggesting that PE induces cell apoptosis by decreasing the mitochondrial transmembrane potential. The Bcl-2 expression level induced by different concentrations of PE was lower than that in control groups. However, the Bax expression level induced by PE was higher than that in the control group. Meanwhile, PE increased the caspase-3 expression in a doseand time-dependent manner. CONCLUSION: Exogenous PE induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway.

Influence of CDK1 and CDK2 siRNA interference on tumor cell cycle and cell apoptosis

Objective： We investigated the influence of CDK1 and CDK2 expression inhibited by cotransfection of CDK1 and CDK2 siRNA on cell cycle and apoptosis, explored the exact role of cell cycle master regulator in tumor cell apoptosis process. Methods： The siRNA targeting the CDK1 and CDK2 genes were synthesized and simultaneously cotransfected into Hela cells by lipofectamine 2000.48 or 60 h after the cotransfection, CDK1 and CDK2 protein expressions were examined by Western blot. Cell cycle distribution was analyzed by flow cytometry. Cell apoptosis was detected by the Annexin V/PI method. The changes of the transfected cell morphological under a microscope after Wright-Giemsa Staining were studied. Results： CDK1 and CDK2 protein expression was decreased at 48 or 60 h after cotransfection. The accumulation of the G2/M and S phase population in cell cycle of the cotransfected cells at 48 or 60 h after transfection was enhanced obviously compared with control. The ratio of apoptotic cell of cotransfected cells at 48 or 60 h after transfection was increased significantly compared with control. More binucleate or multinucleate ceJls among cotransfected cells were observed under the microscope. Conclusion： The decreased expression of CDK1 and CDK2 by cotransfection of CDK1 and CDK2 siRNA not only leads to tumor cell cycle arrest in S phase and G2/M phase, but also induces tumor cell apoptosis.

7-difluoromethoxyl-5,4'-di-n-octylgenistein inhibits growth of gastric cancer cells through downregulating forkhead box M1

AIM: To investigate whether the 7-difluoromethoxyl-5, 4'-di-n-octylgenistein (DFOG), a novel synthetic genistein analogue, affects the growth of gastric cancer cells and its mechanisms. METHODS: A series of genistein analogues were prepared by difluoromethylation and alkylation, and human gastric cancer cell lines AGS and SGC-7901 cultured in vitro were treated with various concentrations of genistein and genistein analogues. The cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were incubated by DFOG at different concentrations. The growth inhibitory effects were evaluated using MTT and clonogenic assay. The distribution of the phase in cell cycle was analyzed using flow cytometric analysis with propidium iodide staining. The expression of the transcription factor forkhead box M1 (FOXM1) was analyzed by reverse transcription-polymerase chain reaction and Western blotting. The expression levelsof CDK1, Cdc25B, cyclin B and p27KIP1 protein were detected using Western blotting. RESULTS: Nine of the genistein analogues had more effective antitumor activity than genistein. Among the tested analogues, DFOG possessed the strongest activity against AGS and SGC-7901 cells in vitro. DFOG significantly inhibited the cell viability and colony formation of AGS and SGC-7901 cells. Moreover, DFOG efficaciously arrested the cell cycle in G2/M phase. DFOG decreased the expression of FOXM1 and its downstream genes, such as CDK1, Cdc25B, cyclin B, and increased p27KIP1 at protein levels. Knockdown of FOXM1 by small interfering RNA before DFOG treatment resulted in enhanced cell growth inhibition in AGS cells. Up-regulation of FOXM1 by cDNA transfection attenuated DFOG-induced cell growth inhibition in AGS cells. CONCLUSION: DFOG inhibits the growth of human gastric cancer cells by down-regulating the FOXM1 expression.

Cardiotrophin-1 promotes cardiomyocyte differentiation from mouse induced pluripotent stem cells via JAK2/STAT3/Pim-1 signaling pathway

Background The induced pluripotent stem cell （iPSC） has shown great potential in cellular therapy of myocardial infarction （MI）, while its application is hampered by the low efficiency of cardiomyocyte differentiation. The present study was designed to investigate the effects of cardiotrophin-1 （CT-1） on cardiomyocyte differentiation from mouse induced pluripotent stem cells （miPSCs） and the underlying mechanisms involved. Methods The optimal treatment condition for cardiomyocyte differentiation from miPSCs was established with ideal concentration （10 ng/mL） and duration （from day 3 to day 14） of CT-1 administration. Up-regulated expression of cardiac specific genes that accounted for embryonic cardiogenesis was observed by quantitative RT-PCR. Elevated amount of a-myosin heavy chain （ct-MHC） and cardiac troponin I （cTn I） positive cells were detected by immunofluorescence staining and flow cytometry analysis in CT- 1 group. Results Transmission electron microscopic analysis revealed that cells treated with CT- 1 showed better organized sacromeric structure and more mitochondria, which are morphological characteristic of matured cardiomyocytes. Western blot demonstrated that CT-1 promotes cardiomyocyte differentiation from miPSCs partly via JAK2/STAT3/Pim-1 pathway as compared with control group. Conclusions These findings suggested that CT-1 could enhance the cardiomyocyte differentiation as well as the maturation of mouse induced pluripotent stem cell derived cardiomyocytes by regulating JAK2/STAT3/Pim-1 signaling pathway.

Vector refinement equation and subdivision schemes in Lp spaces

In this paper we will first prove that the nontrivial L p solutions of the vector refinement equation exist if and only if the corresponding subdivision scheme with a suitable initial function converges in L p without assumption of the stability of the solutions. Then we obtain a characterization of the convergence of the subdivision scheme in terms of the mask. This gives a complete answer to the existence of L p solutions of the refinement equation and the convergence of the corresponding subdivision schemes.

Casticin-induced apoptosis involves death receptor 5 upregulation in hepatocellular carcinoma cells

AIM:To investigate the apoptotic activities of casticin in hepatocellular carcinoma(HCC) cells and its molecular mechanisms.METHODS:PLC/PRF/5 and Hep G2 cell lines were cultured in vitro and the inhibitory effect of casticin on the growth of cells was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolim bromide(MTT) assay.The apoptotic cell death was examined using the cell apoptosis enzyme linked immunosorbent assay(ELISA) detection kit,flow cytometry(FCM) after propidium iodide(PI) staining and DNA agarose gel electrophoresis.The caspase activities were measured using ELISA.Reactive oxygen species(ROS) production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCFH-DA) probe labeling.Intracellular glutathione(GSH) content was measured using a glutathione assay kit.The expression of death receptor(DR)4 and DR5 proteins was analyzed by Western blotting and FCM.RESULTS:Casticin significantly inhibited the growth of human HCC(PLC/PRF/5 and Hep G2) cells in a dosedependent manner(P < 0.05).Casticin increased the percentage of the sub-G1 population in HCC cells in a concentration-dependent manner.The potency of casticin to PLC/PRF/5 cells was higher than that of 5-flurouracil(26.8% ± 4.8% vs 17.4% ± 5.1%) at 10 μmol/L for 24 h.Casticin increased the levels of Histone/DNA fragmentation and the levels of active caspase-3,-8 and-9 in a concentration-dependent manner(P < 0.05).Treatment with 30 μmol/L casticin for 24 h resulted in the formation of a DNA ladder.Casticin reduced the GSH content(P < 0.05),but did not affect the level of intracellular ROS in PLC/PRF/5 and Hep G2 cells.The thiol antioxidants,acetylcysteine(NAC) and GSH restored GSH content and attenuated casticin-induced apoptosis.In contrast,the nonthiol antioxidants,butylated hydroxyanisole and mannitol failed to do so.In the HCC cells treated with casticin for 24 h,DR5 protein level was increased.The expression of DR5 protein induced by casticin was inhibited by NAC.Pretreatment with DR5/Fc chimera protein,a blocking antibody,effectively attenuated the induction of apoptosis by casticin.CONCLUSION:Casticin-induced apoptosis of HCC cells is involved in GSH depletion and DR5 upregulation.

Upregulated CD133 expression in tumorigenesis of colon cancer cells

AIM: To analyze the upregulated CD133 expression in tumorigenesis of primary colon cancer cells. METHODS: Upregulated CD133 expression in tumorigenesis of colorectal cancer cell lines (Lovo, Colo205, Caco-2, HCT116 and SW620) was analyzed by flow cytometry. Human colon cancer tissue samples were stained with anti-human CD133. SW620 cells were sorted according to the CD133 expression level measured by fluorescence-activated cell sorting. Spheroids of colorectal cancer cells were cultured with the hanging drop. Expression of CD133 and Lgr5 in spheroids of colorectal cancer cells and monolayer culture was detected by RT-qPCR. Spheroids of colorectal cancer cells were analyzed using anti-human CD133 with immunohistochemical staining. RESULTS: CD133 antigen was expressed in colorectal cancer cell lines (Lovo, Colo205, Caco-2, HCT116 and SW620) as well as in primary and metastatic human colon cancer tissues. However, the CD133 was differently expressed in these cell lines and tissues. The expression levels of CD133 and Lgr5 were significantly higher in spheroids of parental, CD133hi and CD133-cells than in their monolayer culture at the mRNA level (P < 0.05). Immunohistochemical staining of spheroids of CD133-cells showed that CD133 was highly expressed in colorectal cancer cell lines. CONCLUSION: Upregulated CD133 expression plays a role in tumorigenesis colorectal cancer cells, which may promote the expression of other critical genes that can drive tumorigenesis.

Flow cytometric characterizations of leukocyte subpopulations in the peripheral blood of northern pig-tailed macaques （Macaca leonina）

Pig-tailed macaques(Macaca nemistrina group) have been extensively used as non-human primate animal models for various human diseases in recent years, notably for AIDS research due to their sensitivity to HIV-1. Northern pig-tailed macaques(M. leonina) are distributed in China and other surrounding Southeast Asia countries. Although northern pig-tailed macaques have been bred on a large scale as experimental animals since 2012, the reference value of normal levels of leukocytes is not available. To obtain such information, 62 blood samples from male and female healthy northern pig-tailed macaques at different ages were collected. The normal range of major leukocyte subpopulations, such as T lymphocytes, B lymphocytes, natural killer(NK) cells, monocytes, and the expression levels of activation or differentiation related molecules(CD38, HLA-DR, CCR5, CD21, IgD, CD80 and CD86) on lymphocytes were analyzed by flow cytometry. The counts of B cells decreased with age, but those of CD8+ T cells and NK cells and the frequency of CD38+HLA-DR+CD4+ T cells were positively correlated with age. The counts of leukocyte subpopulations were higher in males than those in females except for CD4+ T cells. Males also showed higher expression levels of Ig D and CD21 within B cells. This study provides basic data about the leukocyte subpopulations of northern pig-tailed macaques and compares this species with commonly used Chinese rhesus macaques(M. mulatta), which is meaningful for the biomedical application of northern pig-tailed macaques.

Morphology and ontogeny of dendritic cells in rats at different development periods

AIM： To study the morphology and ontogeny of dendritic cells of Peyer＇s patches in rats at different development periods. METHODS： The morphometric and flow cytometric analyses were performed to detect all the parameters of villous-crypts axis and the number of OX62＋DC, OX62＋CD4＋SIRP＋DC, and OX62＋CD4-SIRP-DC in the small intestine in different groups of rats. The relationship between the parameters of villous-axis and the number of DC and DC subtype were analyzed. RESULTS： All morphometric parameters changed significantly with the development of pups in the different age groups （F = 10.751, 12.374, 16.527, 5.291, 3.486; P = 0.000, 0.000, 0.000, 0.001, 0.015）. Villous height levels were unstable and increased from 115.24μm to 140.43 μm as early as 3 wk postpartum. Villous area increased significantly between 5 and 7 wk postpartum, peeked up to 13817.60 tam2 at 7 wk postpartum. Villous height and crypt depth ratios were relatively stable and increased significantly from 2.80 ＋ 1.01 to 4.54 =1= 1.56, 9-11 wk postpartum. The expression of OX62＋DC increased from 33.30%±5.80% to 80%± 17.30%, 3-11 wk postpartum （F =5.536, P = 0.0013）. OX62＋CD4＋SIRP＋DC subset levels detected in single-cell suspensions of rat total Peyer＇s patch dendritic cells （PP-DCs） increased significantly from 30.73% ± 5.16% to 35.50% ± 4.08%, 5-7 wk postpartum and from 34.20% ±1.35% to 43.60% ± 2.07% 9-11 wk postpartum （F = 7.216, P = 0.005）. CONCLUSION： This study confirms the agerelated changes in villous-crypt axis differentiation in the small intestine. Simultaneously, there are also development and maturation in rat PP-DCs phenotypic expression. Furthermore, the morphological changes of intestinal mucosa and the development of immune cells （especially DC） peaked at 9-11 wk postpartum, indicating that the intestinal mucosae reached a relatively mature state at 11 wk postpartum.

MicroRNA-15a/b are up-regulated in response to myocardial ischemia/reperfusion injury

Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion （I/R） injury.Methods Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo,while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation （H/R）.Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.Results Compared to those of the controls,I/R or H/R induced apoptosis of cardiomyocytes was significantly iucreased both in vivo （24.4％ ± 9.4％ vs.2.2％ ± 1.9％,P ＜ 0.01,n =5） and in vitro （14.12％ ±0.92％ vs.2.22％ ± 0.08％）.The expression of miR-15a and miR-15b,but not miR-16,was increased in the mice I/R model,and the results were consistent in the H/R model.Conclusions Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury,therefore,down-regulation of miR- 15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.

ZM-66, a New Podophyllotoxin Derivative Inhibits Proliferation and Induces Apoptosis in K562/ADM Cells

Objective To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM. Methods The K562/ADM cells were treated with varying concentrations （0, 1, 2, 4×10^-3 mmol/L） of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt （SRB） assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein （P-gp）, P53 and Bax protein in K562/ADM cells were detected by Western blot assay. Results SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 （1, 2, 4×10^-3 mmol/L） had significantly inhibitory effect on K562/ADM cells （all P〈0.01）. The acridine orange/propidium iodide dual staining showed that there were typical condensation of chromatin and nuclear fragmentation nuclei with red color in ZM-66 treated cells. Flow cytometric analysis showed that there was a significantly increase of apoptotic cells i~ K562/KDM cells after treated with ZM-66. RT-PCR showed that the p53 and bax mRNA expression levels in K562/ADM cells treated with ZM-66 at 1, 2, 4×10^-3 mmol/L were higher than those in the cell without treatment. Western blot showed that the P53 and Bax protein expression levels in K562/ADM cells treated with ZM-66 at 2, 4x 10 s mmol/L were higher than those in the cell without treatment. But the P-gp protein expression level in K562/ADM cells treated with ZM-66 at 2, 4×10^-3 mmol/L was gradually lower than those in the cell without treatment. Conclusion ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of theapoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.

Mechanism Analyses for Elucidating the Role of LOXL2 Silencing in Hepatocellular Carcinoma

The paper aimed to study the effect of lysyl oxidase-like 2 （LOXL2） on hepatocellular carcinoma （HCC） and explore the biological mechanisms of tumorigenicity and progression in HCC. The authors used four HCC cell lines to identify LOXL2. A lentiviral vector containing LOXL2-siRNA was constructed to silence the LOXL2 gene in SMMC-7721 cell line, and mRNA of the target gene was detected by real-time polymerase chain reaction （RT-PCR）. The effect of LOXL2 silencing on the growth of SMMC-7721 cells was explored with flow cytometry profiling and BrdU labeling. Downstream genes of LOXL2 were selected by microarray and verified by Western Blotting. In the results, LOXL2 expression was significantly up-regulated in four types of HCC cell lines, therefore, SMMC-7721 cell line was selected for further exploration. When SMMC-7721 cell line was infected with LOXL2-siRNA, the expression of LOXL2 mRNA decreased. The silencing of LOXL2 resulted in the cell cycle arrest at the G 1-phase, the increased apoptosis and the decreased growth of SMMC-7721 cells on the indicated days by BrdU. Moreover, the MDM2, BIRC3, CDC42, FOS and TGFBR2 genes were selected and verified to be the downstream genes of LOXL2. In conclusion, LOXL2 contributes to the genesis and progression of HCC cells and works by regulating downstream genes of LOXL2 in certain pathways. Therefore, LOXL2 may play an important role in the progression and prognosis of HCC.

Proliferation inhibition of human cervical cancer HeLa cells by Casticin in vitro

Objective： The aim of the study was to investigate the effect of Casticin on proliferation inhibition of human cervical cancer HeLa cells in vitro and to unravel the associated mechanisms. Methods： Human cervical HeLa cells were cultured in vitro. The inhibitory effect of Casticin on the viability of human cervical cancer HeLa ceils was evaluated by the MTT assay. The colony formation ability was detected by plate colony formation assay. Distribution of cell cycle was analyzed by flow cytometry. The protein expression levels were analyzed by Western blot. Results： Casticin significantly inhibited the growth of human cervical cancer HeLa cells in a dose- and time-dependent manner, and the IC50 was 2.82 μg/mL. The colony-forming rate was reduced drastically compared with control group （P 〈 0.05）. The cells were markedly arrested at G2/M phase after the treatment of Casticin for 48 h. Western blot showed that the expression of p21 protein was up-regulated and protein level of Cyctin B1 was depressed by Casticin in a concentration dependent manner. Conclusion： Casticin could inhibit the cell growth and lead to cell arrest in human cervical cancer HeLa cells, and the down-regulation of Cyclin B1 protein expression and activation of p21 protein might contribute to Casticin induced cell arrest in human cervical cancer HeLa cells.