Apoptotic Effects of Hypocrellin A on HeLa Cells

Hypocrellin A（ HA）, a photosensitive perylenequinone compound of Hypocrella bambusae, inhibited the proliferation of several tumor cell lines. Human cervical cancer cells, HeLa ceils, were used as a model to elucidate the molecular mechanisms of HA-induced tumor cell death. The results show that HA can induce the oligonucleosomal fragmentation of DNA in HeLa cells and also can increase the expression of apoptosis inducer Bax mRNA and that it decreases the expression of apoptosis suppressor, Bcl-2 mRNA, in mitochondria. It can be concluded from the data that HA-induced apoptosis is related to the balance between Bcl-2 and Bax gene expressions.

Quercetin Suppresses HeLa Cells by Blocking PI3K/Akt Pathway

To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin- V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were ob- served under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related pro- teins in the HeLa cells were assessed by Western blotting. The results showed that quercetin signifi- cantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate ex- pression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix oancer.

TRICHOSTATIN A INHIBITS PROLIFERATION,INDUCES APOPTOSIS AND CELL CYCLE ARREST IN HELA CELLS

Objective： The histone deacetylase inhibitors （HDACIS） have been shown to inhibit cancer cell proliferation, stimulate apoptosis, an induce cell cycle arrest. Our purpose was to investigate the antiproliferative effects of a HDACI, trichostatin A （TSA）, against human cervical cancer cells （HeLa）. Methods： HeLa cells were treated in vitro with various concentrations of TSA. The inhibitory effect of TSA on the growth of HeLa cells was measured by MTT assay. To detect the characteristic of apoptosis chromatin condensation, HeLa cells were stained with Hoechst 33258 in the presence of TSA. Induction of cell cycle arrest was studied by flow cytometry. Changes in gene expression of p53, p21wafl and p27Kipl were studied by semiquantitative RT-PCR. Results： TSA inhibited cell growth in a time- and dose-dependent manner. Hoechst 33258 staining assay showed that TSA induced apoptosis. Cell cycle analysis indicated that treatment with TSA decreased the proportion of cells in S phase and increased the proportion of cells in G0/G1 and/or G2/M phases of the cell cycle. This was concomitant with overexpression of genes related to malignant phenotype, including an increase in p53, p21wall and p27Kipl. Conclusion： These results suggest that TSA is effective in inhibiting growth of HeLa cells in vitro. The findings raise the possibility that TSA may prove particularly effective in treatment of cervical cancers.

INHIBITION AND RADIATION SENSITIZING EFFECT OF INDOLEACETIC ACID COMBINED WITH HORSERADISH PEROXIDASE ON HELA CELLS

Objective To observe the inhibition and radiation-sensitizing effect of Indoleacetic acid (IAA) combined with horseradish peroxidase(HRP)on Hela cells. Methods Hela cells were cultured in vitro and classified into control group, drug group incubated with different doses of IAA(30, 60, 90μmol·L -1) plus 1.2μg·mL -1 HRP, radiation group (6MV-X, 4Gy ) and group of radiation plus IAA plus HRP(same dose as above). All the above were treated for 24-96 hours.The growth inhibition, radiation-sensitizing effect were observed with methyl thiazolyl tetrazolium (MTT) photocolorimetric assay and trypan blue dye assay. The-effect on cell proliferation cycle was determined by flow cytometry. Results The antiproliferation activities showed a significant time-effect and dose-effect relationship to some extent after Hela cells were treated with IAA combined with HRP. The group of radiation plus 60μmol·L -1 IAA plus 1.2μg·mL -1 HRP and radiation plus 90μmol·L -1 IAA plus 1.2μg·mL -1 HRP showed an obvious radiation sensitizing effect. After treatment with 90μmol·L -1 IAA plus 1.2 μg·mL -1 HRP for 72 hours, the determination of cell cycle showed that the percentages of the cells on stages G 2-M and S were all higher than those of the control group. For the group of radiation plus IAA combined with HRP, the percentages of the cells on stages G 2-M were higher than those of the radiation group. Conclusion The above findings suggest that IAA combined with HRP has an inhibitive and killing effect on Hela cells. The effect was stronger during the cell cycles of G 2-M and S. It also has a radiation sensitizing effect. Its mechanism might be that Hela cells were blocked on stages G 2-M, and it presents a collaborative killing effect during miototic time.

Effect of Regulation of HSV-tk Gene Expression and Tumor Killed Activity with a Single Tetracycline-regulatable Plasmid Vector on HeLa Cells

To construct a single tetracycline-regulatable plasmid vector based on the double tetracycline-regulatable plasmid vector system for regulating HSV-tk gene expression so as to effectively kill HeLa cells. Two tetracycline operator（TetO2） was cloned into pcDNA3.1 and a cassette was made for a cytomegalovirus-type 2 tetracycline operator（CMV-TetO2） promoter, and the obtained vector was named pcDNA3.1-CMV-TetO2. Herpes simplex virus thymidine kinase（HSV-tk） gene and tetracycline repressor（TR） gene were cloned into pcDNA3.1-CMV-TetO2 and the two genes were linked with internal ribosome entry site（IRES） to gain a vector named pcDNA3.1-CMV-TetO2- HSV-tk-IRES-TR. The HeLa cells were stablly transfected with pcDNA3.1-CMV-TetO2-HSV-tk-IRES-TR plasmid. The expression of HSV-tk and TR were detected by RToPCR, the tumorcidal activity of HSV-tk/GCV was determined by MTT assay. In Hela cells transfected with the above plasmid vector, HSV-tk gene and TR gene can be expressed lowly and the concentration of GCV producing a 50% decrease in cell viability was about 50 lag/mL without adding deoxycycline; in contrast, the expessions of HSV-tk gene and TR gene increased significantly and the concentration of GCV producing a 50% decrease in cell viability was about 5 μg/mL with adding deoxycycline. Therefore tetracycline can regulate the expression and tumorcidal activity of HSV-tk gene in HeLa cells with this single plasmid vector.

Overexpression of inhibinα(1-32)fusion protein promotes apoptosis and cell cycle arrest in a cervical cancer cell model(Hela cells)

Inhibins play important roles in the reproductive system. To evaluate whether inhibin α (1-32) fusion protein plays a role in cervical cancer growth, the plasmid pVAX-inhα was constructed and its effect on proliferation and apoptosis of the human cervical cancer cell line (Hela) was checked by flow cytometry and real-time PCR. The expression and localization of inhibin α protein were detected by RT-PCR and confocal mi- croscopy which showed that inhibin α protein was expressed and localized in the nucleus of Hela cells. Over ex- pression of inhibin α gene significantly induced cell apoptosis and ceased S phase of cell cycle. Furthermore, cell proliferation was significantly suppressed 96 h post-transfection and mRNA level of anti-apoptosis genes (Bcl-2, NFκB) were decreased but pro-apoptosis genes (Bax, wild type p53) and inhibin co receptor (TGFβR3) were increased, indicating that inhibin, through its co-receptor, might activate apoptotic and cell growth cascades which regulate proliferation and apoptosis in Hela cells. These results suggest that inhibin α (1-32) fusion pro- tein, located in the cell nucleus, can regulate Hela cells growth and apoptosis by induction of apoptotic pathways such as NFκB, Bcl-2 and p53 families. These findings may have a significant impact on future research regarding cervical cancer cell lines.

The Effect of Fullerenol Combined with Cisplatin on the Proliferation of Cervical Cancer HeLa Cells

This study aimed to investigate the effect of fullerenol combined with cisplatin on the proliferation of cervical cancer HeLa cells in order to provide new ideas and laboratory theoretical basis for the clinical treatment of cervical cancer. Cervical cancer cell line HeLa cells in vitro were treated with different concentrations of fullerenol, different concentrations of cisplatin, and different concentrations of fullerenol combined with cisplatin, after 24 h, 48 h, 72 h, microscope changes in cell morphology;MTT assay was used to determine the effect of drugs on the proliferation of HeLa cells. Fullerenol and cisplatin alone can inhibit the proliferation of HeLa cells in a dose-dependent and time-dependent manner;compared with cisplatin alone, different concentrations of fullerenol combined with cisplatin significantly increased the apoptosis rate of HeLa cells (P < 0.05). The inhibition of fullerenol combined with cisplatin on HeLa cells in vitro is more significant, resulting in a stronger anti-cancer effect.

Effects of Livin Gene RNA Interference on Apoptosis of Cervical Cancer Hela Cells and Enhanced Sensitivity to Cisplatin

The recombinant plasmids pGenesil-1-BIRC71 and pGenesil-1-BIRC72 were transfected into Hela cells and cisplatin was added with different concentrations in order to study the inhibitory effects of Livin gene, increase the apoptosis induced by cisplatin, and detect the expression ofBcl-2, Bax, caspase-3, and survivin genes. The pGenesil-1-BIRC71 and pGenesil-1-BIRC72 were transfected into Hela cells, and the expression levels of Livin, Bcl-2, Bax, caspase-3, and survivin genes were detected by using fluorescence quantitative real-time PCR. Then cisplatin at different concentrations （3.0, 6.0 and 9.9 μg/mL） was added into the transfected Hela cells, and 24, and 48 h later, the apoptosis rate was measured by flow cytometry. After transfection of pGenesil-l-BIRC71 and pGenesil-1-BIRC72 into Hela cells, the expression level of Livin gene was obviously reduced, and the apoptosis rate was significantly increased in transfection group as compared with control group （P〈0.05）. Cisplatin could increase the apoptosis rate in a dose- and time-dependent manner. After cisplatin was added, the expression levels of Bcl-2 mRNA were reduced, and those of Bax, caspase-3, and survivin mRNA were increased in transfection group as compared with those in control group （P〈0.05）. It was concluded that shRNA expression vector targeting Livin gene could inhibit the expression of Livin gene in Hela cells and enhance the apoptosis induced by cisplatin, which was related to the decreased expression of Bcl-2 and activation of Bax and caspase-3. Survivin might play an important role as an antagonist in the process of apoptosis induction.

Ginsenoside Rh_2 Showing Ability to Induce Apoptosis in HeLa Cells

This paper deals with the inhibitory mechanisms of ginsenoside \{G Rh 2\} on the growth of tumor cells. \{G Rh 2\} significantly inhibited the proliferation of human cervical adenocarcinoma HeLa cells in a time and dose dependent manner. G Rh 2 induced apoptotic manifestations in HeLa cells as evidenced by the changes in the cell morphology, the DNA fragmentation and the activation of caspases. Caspase inhibitors, caspase family inhibitor, z Val Ala Asp fmk(z VAD fmk); caspase 1 inhibitor, Ac Tyr Val Ala Asp chloromethyl ketone(Ac YVAD cmk); caspase 3 inhibitor, z Asp Glu Val Asp fmk(z DEVE fmk) and caspase 8 inhibitor, \{z Ile \}Glu Asp fmk(z IETD fmk) effectively attenuated G Rh 2 induced cell death. The activities of caspase 1 and caspase 3 were increased in the G Rh 2 induced apoptotic process. However, caspase inhibitors can not inhibit G Rh - 2 induced cell death completely. These results suggest that G Rh 2 induced cell death is mediated by the activation of caspase cascade, but there might be some other pathways for induction of this apoptosis.

Immune Killing Activity of Lymphocytes on Hela Cells Expressing Interleukin-12 In Vitro

The killing effects of lymphocytes on Hela cells expressing interleukin-12 （IL-12） in vitro were explored. By using gene transfection technique, full length IL-12 gene was transfected into Hela cells. The expression of IL-12 in Hela cells was detected quantitatively by ELISA; Changes in killing effects of lymphocytes on Hela cells expressing IL-12 were observed by MTT. It was found that Hela cells could express IL- 12 between 24 h and 72 h after transfection. Killing activity of lymphocytes on Hela cells expressing IL-12 was significantly enhanced. It was concluded by cell transfection technique, Hela cells could express 1L-12 and were more easily killed by lymphocytes.

hSHIP induces S-phase arrest and growth inhibition in cervical cancer HeLa cells

hSHIP, a human SH2-containing inositol-5-phosphatase, acts as a negative regulator of proliferation and survival in hematopoietic cells. Therefore, hSHIP may play a crucial role in suppression of cervical cancer HeLa cells. In this study, pcDNA3.1-hSHIP-GFP plas- mid was constructed and transfected into HeLa cells with Lipofectamine2000, stably transfected HeLa cells were established and their responses were investigated by Flow cytometry, MTT, tumorigenicity in nude mice, RT-PCR and ELISA assays. The results showed that the expression of hSHIP significantly induced S-phase arrest, cell growth inhibition, and down-regulation of Aktl/2 mRNA and p-Akt in HeLa cells. Our study supports an important role for hSHIP in suppression of cervical cancer HeLa cells, which may prove to be a novel therapeutic option for non-hematopoietic cancers.

Comparative study of the cytotoxicity of the nanosized and microsized tellurium powders on HeLa cells

To compare the cytotoxicity on HeLa cells induced by nanosized and microsized tellurium powders, HeLa cells were exposed to different concentrations of tellurium powders （0, 50, 100, 150 and 200 μg/mL） for 12 h. In this study, detection of a series of biomarkers, including reactive oxygen species （ROS）, glutathione （GSH）, 8-hydroxy-2＇- deoxyguanosine （8-OHdG）, in addition to DNA and protein crosslink （DPC） and MTT assay, were conducted to evaluate the cytotoxicity. It is indicated that compared with the control group, there was no significant difference in the induced cytotoxicity at concentrations lower than 50 μg/mL for both nanosized and microsized tellurium powders. While there appears a significant difference in the induced cytotoxicity for nanosized tellurium powders when the concentration is higher than 100 μg/mL as well as for microsized tellurium powders when the concentration is higher than 200 μg/mL. Moreover, it is found that the cytotoxicity induced on HeLa cells exhibits a certain dose-effect relationship with the concentration of tellurium powders. A conclusion has been reached that the toxicity on HeLa cells can be induced by both nanosized and microsized tellurium powders, and the toxicity of the nanosized tellurium powders is significantly greater than the microsized one.

PLGA nanoparticle encapsulated paclitaxol for sustained release and its anticancer effect for HeLa cells in vitro

Poly (D,L-lactide-co-glycolide) (PLGA) is a biodegradable and biocompatible polymer material for drug deliver system. The aim of this study is to synthesize drug-loaded

Involvement of the Mitochondrion-dependent and the Endoplasmic Reticulum Stress-signaling Pathways in Isoliquiritigenin-induced Apoptosis of HeLa Cell

Objective Isoliquiritigenin （ISL）, a licorice chalconoid, is considered to be a bioactive agent with chemopreventive potential. This study investigates the mechanisms involved in ISL-induced apoptosis in human cervical carcinoma HeLa cells. Methods Cell viability was evaluated using a 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyl-tetrazolium bromide （MTT） assay. Apoptosis was determined by flow cytometry using an Annexin V-FITC Apoptosis Detection Kit. The intracetlular ROS levels were assessed using a 2, 7-dichlorofluorescein probe assay. The mitochondrial membrane potential was measured with the dual-emission potential-sensitive probe 5, 5＇, 6, 6＇-tetra-chloro-1, 1＇, 3, 3＇-tetraethyl-imidacarbocyanine iodide （JC-1）. The degradation of poly-ADP-ribose polymerase （PARP） protein, the phosphorylation of PKR-like ER kinase （PERK）, the phosphorylation of the a-subunit of eukaryotic initiation factor 2 （elF2a）, the expression of the 78 kD glucose-regulated protein （GRP 78）, and the activation of caspase-12 were analyzed via western blot analysis. Results ISL significantly inhibited the proliferation, the increase in ROS levels and apoptotic rates of HeLa cells in a concentration-dependent manner. Moreover, ISL induced mitochondrial dysfunction, caspase activation, and PARP cleavage, which displayed features of mitochondria dependent on apoptotic signals. Besides, exposure of HeLa cells to ISL triggered endoplasmic reticulum （ER） stress, as indicated by the increase in p-elF2a and GRP78 expression, ER stress-dependent apoptosis is caused by the activation of ER-specific caspase-12. Conclusion The findings from our study suggest that ISL-induced oxidative stress causes HeLa cel apoptosis via the mitochondrion-dependent and the ER stress-triggered signaling pathways.

Effect of Quercetin on Breeding and Apoptosis of Cervical Cancer HeLa Cell and on Growth of Transplanted Tumor in Nude Mice

Effect of quercetin on HeLa cell system of cervical cancer was studied by methods of MTT and Annexin V-FITC/PI. The results show that quercetin has functions of inhibiting breeding of HeLa cells and inducing apoptosis of the cells. The total apoptosis rate is positively proportional to reaction duration and concentration of quercetin used. The maximum apoptosis rate being （88.76±2.35）% was obtained when the concentration was 50.0 μmol/L and the cells were treated with quercetin for 72 hours. Based on establishing a model of tumor of cervical cancer transplanted into nude mice, quercetin of different concentrations was injected into abdominal cavity of nude mice and situation of tumor growth was reviewed. The result showed that with quercetin concent＇ration increasing from 0 to 100.0 μmol/L, the transplantation volume and weight of the tumors decreased from （279.59±70.58） mm^3 and （0.145±0.019） g to （128.72±36.12） mm^3 and （0.089± 0.019） g respectively, while apoptosis rate of the transplanted tumor increased from （9.63±1.85）% to （34,98±0.47）%, which proved that quercetin inhibited increment of volume and weight of transplanted tumor in nude mice bodies.

Shikonin from Chinese herbal medicine induces GSDME-controlled pyroptosis in tumor cells

Objective:To investigate the potential anti-tumor mechanisms of naphthoquinone compound shikonin(SKN)extracted from the root of Chinese herbal medicine plant lithospermum(Lithospermum erythrorhizon Sieb.&Zucc.).Methods:We first observed that SKN treatment led to swelling and bubbles in HeLa cells that were similar to the phenotype of cell pyroptosis.Subsequently,the HeLa cells experienced a pyroptotic process with SKN,and this was then assessed using lactate dehydrogenase(LDH)release and propidium iodide(PI)/Hoechst double staining experiments.Pyroptosis is defined as gasdermin-mediated programmed necroptosis.To identify the potential pyroptosis machinery,two strategies were utilized that included a genome-wide clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9 screening experiment and a pyroptosis reconstitution assay executed by each of the five known gasdermins(GSDMA-E).Moreover,endogenous cleavage was also detected in a panel of tumor cell lines.Results:Compared with the control,both the LDH release and PI/Hoechst double-staining experiments suggested that SKN induced perforation and enhancement of the permeability of the cell membranes that resulted in pyroptosis in HeLa cells(P=.028 and P=.032,respectively).In addition,the reconstitution assays in human embryonic kidney 293T(HEK-293T)cells and endogenous cleavage assays in HeLa cells indicated that the pyroptosis was controlled by GSDME.In addition,we also found SKN could trigger pyroptosis in a panel of tumor cell lines in which the cellular morphologies were proportional to the GSDME expression levels.Additionally,the cleavage of GSDME was also detected,and this was indicative of a similar GSDME-mediated mechanism.Conclusion:Our study not only explained the molecular mechanism of cytotoxicity of SKN to various tumor cells,but also provided additional information for the potential clinical application of natural naphthoquinone compounds against cancer.

Experimental Studies on Cyclooxygenase-2 Inhibitor Induced Cervical Cancer Hela Cell Apoptosis and Its Molecular Mechanism

Objective To investigate the Hela cells growth inhibition and apoptosis possible molecular mechanisms. Methods Hela cells were treated with various concentrations （100μmol/L,200μmol/L, 300 μmol/L, 400 μmol/L） of NS-398 （selective for COX-2 inhibition）. Cell growth was measured by MTT （Thiazolyl blue）. Apoptosis was detected by double staining flow cytometry （FCM）. Levels of PGE： were measured by radioimmunoassay. The expressions of COX-2 protein were also examined by Western blot analysis. Results After treated with different concentrations of NS-398, the growth of Hela cells was suppressed significantly in a dose-and time-dependent manner （P〈0.01）. The NS-398 can induce apoptosis with the apoptosis rates at 8.53%-43.46% by FCM in a dose-dependent manner. The release of PGE2 was reduced in Hela cells with the values of 69.26 ± 2.13, 47.46 ± 2.18, 28.15 ± 1.64 and 17.01 ± 1.12, respectively, there was significant difference compared with control group （83.78 ± 1.11） （P〈0.01）. The NS-398 could inhibit the activity and expression of COX-2 in a dose- dependent manner and down-regulated the expression of COX-2 protein greatly. Conclusion NS-398 could inhibit the proliferation and increase apoptosis in human Hela cells. These effects may be depended on the inhibition of the expression of COX-2 and PGE2 by NS-398.

STUDY OF ENHANCED IMMUNOGENECITY OF B7-1 GENE TRANSFECTED HUMAN HELA CELL LINE

This work was supposed by CMB (No. 96—635) This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Although cervical carcinoma cells may express the human papillomavirus protein E6 and E7, they fail to induce an effective specific cytotoxic T lymphocyte response. Recent studies suggest that expression of CD 80 (B7 1) on tumor cells is effective to induce antitumor immune responses. 1,2 In our study, CD 80 gene was transfected into human Hela cell line with a CD 80 expression plasmid (B7 1 +pcDNA 3) by electroporation, then the immunogenecity of the modified Hela cell was tested in TLMC (tumor lymphocyte mixed culture) system. Thymidine lymphocyte proliferation assays showed that the response of human peripheral blood lymphocytes (PBLS) to CD 80 positive Hela cells demonstrated a substantial increase in cell proliferation compared to the response to control cells. Cocultivation of allogeneic PBLs with CD 80 positive tumor cells for three days can induce an increased secretion of IL 2. Our results demonstrate an immunostimulatory effect of CD 80 expression on cervical cancer cells, which provides a basis for the development of a therapeutic tumor vaccine.

STUDY ON THE ULTRASTRUCTURE OF SINGLE HeLa CELL TREATED WITH HpD PLUS LASER MICROIRRADIATION

A method is described which permits transmission electron microscope of single cells treated with HpD plus laser microirradiation. The preselected single cell that was irradiated by laser under light microscope and followed fixation, embedded and sectioning is examined under electron microscope. The results demonstrated that at the light dose of 1.88 ml/μm2 not only the irradiated nucleolus appeared transparent region, but the other parts such as non-irradiated mitochondria in cytoplasm can also be damaged. When partial cytoplasm is irradiated with the light dose of 4.50 ml/μm2, the damages appear in all cytoplasm, but there is little change in the nucleus. The experimental results also demonstrate that cytoplasm is more sensitive than nucleus. It is the mitochondria in cytoplasm that are very sensitive to HpD plus laser.

A New Glance on Energy Metabolism Investigation in Cultured Cells

The aim of the study was to analyze the input of cytosolic and oxidative pathways of energy metabolism in ATP production of cultured cells by using FLIM and routine biochemical techniques. Fluorescent imaging of endogenous cofactors NADH and FAD demonstrated a more pronounced oxidative redox status of fibroblasts compared to tumor cells and significant differences in metabolic processes in which FAD is involved. Analysis of glucose and lactate content and absorption showed that tumor cells not only absorb glucose more intensively from the environment, but also use it more intensively during anaerobic glycolysis. Lower energy efficiency of glycolysis and FAD oxidative path and greater energy consumption is the reason for the lower concentration of ATP in tumor cells. Presumably, the prevalence of glycolytic metabolism in tumor cells could be largely determined by their hypoxic reprogramming through the PI3K/AKT/mTOR signal pathway. The results of the study suggest that correlation between intracellular consumption of glucose and cytosolic concentration of NADH may contribute to the characteristic of energy metabolism state of cultured cells and serve as the biosensor of malignant cell transformation.