Influences of Melatonin on the Growth of HeLa Cells

Aim To investigate the influences of melatonin (MT) on the growth of HeLa cells in vitro. Methods Theantiprolfferation activities of MT were evaluated in HeLa cells by means of trypan blue dye exclusion and MTT vital staining.The morphological changes of HeLa cells induced by MT were observed under transmission electronic microscope. Cell divisioncycle influenced by MT was assessed by a flow cytometry. Results MT produced a certain inhibition of HeLa cells at the con-centration of 2 mmol@ L-1 and prolonged the TD. The fraction of cells inhibited was 61.0%. The IC. so of HeLa cells exposed toMT for 96 h was 2.039 mmol@ L- 1. The flow cytometric analyses showed that exposure to MT for 72 h reduced the number ofHeLa cells in phase S. Under electronic microscope, the HeLa cells exposed to MT for 72 h displayed morphological changesof necrosis, apoptosis, more hetero-chromosome and less somatic chromosome. Conclusion MT showed certain influences onthe growth of HeLa cells. Its mechanism may probably be attributable to reduction of the number of cells in phase S.

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.

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.

Effects of antisense oligonucleotides targeting VEGF on radio sensitivity of uterine cervix cancer Hela cells

Objective： To determine the impact of antisense oligonucleotides targeting vascular endothelial growth factor （VEGF） on radiosensitivity of uterine cervix cancer Hela cells. Methods： VEGF antisense oligodeoxynucleotides （ASODN） was transfected into Hela cells by liposome-mediated method. Cells transfected with the oligodeoxynuclecotide and saline were used as control groups. Cells were irradiated by 6 MV X ray at the dose of 0 Gy, 2 Gy, 4 Gy and 6 Gy respectively. The expression of VEGF mRNA was determined by RT-PCR. Apoptosis were evaluated using FCM. Cloning efficiency was determined by colony formation assay. Results： The expression of VEGF mRNAwas inhibited by ASODN （P 〈 0.01） in Hela cells. The inhibited activation which was influenced by radiation resulted in increasing apoptosis （P 〈 0.01） and inhibiting plating efficiency （P 〈 0.01）. Conclusion： The expression of VEGF induced by X irradiation in Hela cells can be blocked by VEGF ASODN. Treatment with VEGF might increase apoptosis in HeLa cells and enhance radiosensitivity.

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.

Effect of aspirin alone or combined with cisplatin on human cervical carcinoma HeLa cells

Objective： To study the effect and mechanism of aspirin alone or combined with cisplatin （DDP） on human cervical carcinoma HeLa cells. Methods： HeLa cells were treated by different concentrations of aspirin, DDP alone or both. The inhibitory effect on cell growth was analyzed by MTT and colony-forming assay. Cell apoptosis was measured with flow cytometry. The mRNA levels ofBcl-2, Bax and NF-κB（P65） were studied by RT-PCR. Results： MTT assay showed that aspirin inhibited HeLa cell proliferation in a time-and dose-dependant maoner. Aspirin decreased clone numbers in colony formation assay. Aspirin also induced apoptosis of HeLa cells in a dose- and time-dependent manner as detected by flow cytometry. The inhibition effects on proliferation, colony formation and apoptosis were significantly enhanced when cells were treated with both aspirin and DDP. RT-PCR demonstrated that aspirin decreased the transcription of Bcl-2 and NF-κB, and increased expression of Bax gene. Conclusion： Aspirin can induce apoptosis in HeLa cells. Combination of aspirin and DDP displays a synergistic effect. The possible mechanism might be that aspirin downregulates the mRNA levels of Bcl-2 and NF-κB gene and upregulates the expression of Bax.

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.

Cell-cycle-dependent variation in UV absorption spectrum of Hela cells treated with Trichostatin A

Objective： The aim of our study was to discovery the different cell cycle arrest effect after different densities HeLa cells treated with Trichostatin A （TSA）. In addition, this study would find some important relationship between cycle arrest effect and UV absorption spectrum of cell. Methods： 0.2 IJM TSA was applied to act on HeLa cells of different density. Then, the cycle arrest effect and UV absorption spectrum of cells were investigated, which provide support to analyze the effect of TSA on cancer cells. Results： Cell cycle arrest effect in G0/G1 of the lower density cells was more obvious than that in other groups. The other discovery in this work was that the cellular UV absorption value was higher when the density of cultured cell was lower. Conclusion： This experiment would guide the clinical study on early or late stage cancer patients in the future. On the other hand, this work indicates when cells were arrested in G0/G1 phase, the cellular absorption value increased at the same time, so UV absorption spectrum could characterize the change of cell cycle.

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.

Effects of trichostatin A(TSA)on growth and gene expression in HeLa cells

Objective： To investigate the expressions of p53, RB1, Fas, c-fos, Ras, EGFR mRNA in human cervical cancer （HeLa） cell in response to the trichostatin A （TSA）. Methods： We took count of HeLa cells in different incubation times with TSA （0.2μm/L）. The result indicated that HeLa cells changed evidently when HeLa cells were incubated for 36 h. Then, we investigated the genes expression （mRNA levels） of HeLa cells after treatment for 36 h using SYBR green real-time PCR. Results： We demonstrated that trichostatin A （TSA） could make human cervical cancer （HeLa） cell morphological change and induce HeLa cell apoptosis. Furthermore, the data suggest that TSA-induced down-regulation of p53, RB1, Fas, but upregulated c-fos gene expression after treatment for 36 h, and Ras, EGFR did not show obvious response to TSA treatments. Conclusion： TSA has different effects on gene expression.

Induction of Apoptosis in HeLa Cells by Methanolic Extract of Litsea cubeba Fruit Residue from Essential Oil Extraction

Anticancer activity in vitro ofLitsea cubeba fruit extracts was investigated, focusing on the fruit residue from essential oil extraction. The methanol extract was fractionated by an Amberlite XAD-7 column. Cell viability, cell proliferation and cell death were determined using conversion of WST-8, BrdU incorporation and measurement of released LDH, respectively. Activation of caspase-3/-7 was detected using Z-DEVD-R substrate and morphological characteristics of apoptotic cells were revealed by DAPI staining. It was found that 80-100% methanol fractions （RME-4B, -5A, -5B and -5C） were effective against HeLa cell viability and also promoted cell death. RME-SA and -5B were highly effective in suppressing DNA replication （IC50 4.89 and 3.26 g/mL at 48 h） and also in activation of caspase-3/-7 （9 and 17 times of untreated population at 12 h）. The presence of apoptotic bodies was clearly observed. The results of this study suggested that L. cubeba fruit residue has remarkable apoptosis induction potential for further use in cancer drug research and for waste management in the essential oil industry.

Protective effects of Rad23 protein on ultraviolet damage to HeLa cells

Protein Rad23, a nucleotide excision repair factor, mainly involves in repairing the DNA damage from environment, such as UV light. The function of Rad23 protein involved in DNA damage repair from many environmental factors has been studied extensively, but it is not clear from ultraviolet irradiation. To further investigate the photo-protective function of Rad23 protein on HeLa cells damaged from UV light irradiation, firstly, HeLa cells were irradiated by UV light and incubated with the fusion protein of pCold-Rad23, then the cell viability and apoptosis rate were detected by MTT and Hoechst33342/Pl fluorescent staining, respectively. The results show that the recombinant Rad23 protein can protect the HeLa cells from UV irradiation, and inhibit the apoptosis of HeLa cell by UV irradiation.

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