• Molecules and Cells
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• v.41 no.12
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• pp.1045-1051
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• 2018

The developmentally regulated GTP binding protein 2 (DRG2) is involved in the control of cell growth and differentiation. Here, we demonstrate that DRG2 regulates microtubule dynamics in HeLa cells. Analysis of live imaging of the plus-ends of microtubules with EB1-EGFP showed that DRG2 deficiency (shDRG2) significantly reduced the growth rate of HeLa cells. Depletion of DRG2 increased 'slow and long-lived' subpopulations, but decreased 'fast and short-lived' subpopulations of microtubules. Microtubule polymerization inhibitor exhibited a reduced response in shDRG2 cells. Using immunoprecipitation, we show that DRG2 interacts with tau, which regulates microtubule polymerization. Collectively, these data demonstrate that DRG2 may aid in affecting microtubule dynamics in HeLa cells.

• Journal of Photoscience
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• v.9 no.2
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• pp.479-481
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• 2002

UV-induced DNA damage causes cell killing and mutations leading to carcinogenesis. In normal human cells, UV damage such as cyclobutane pyrimidine dimers (CPDs) and primidine-prymidone (6-4) photoproducts are mainly repaired by nucleotide excision repair mechanism. The molecular processes have been well characterized recently. To know the influence of mitochondrial genome on the nucleotide excision repair mechanism against CPDs, we comparatively examined the production of CPDs by UVC irradiation and their repair kinetics in human cells completely lacking mitochondrial DNA (mtDNA) and the parental HeLa S cells. Whole DNA extracted from the cells exposed to UVC was treated with T4-endonuclease V to break the phosphodiester bond adjacent to CPDs. The DNA was electrophoresed in a denaturing agarose gel, which was visualized by ethidium bromide staining. The relative amount of CPDs was determined by image analysis using NIH Image software. MtDNA- less (rho-O) cells were apparently more sensitive to UVC than HeLa S cells, while the level of induction of CPDs in rho-O and HeLa cells was comparable. The repair of CPDs was less efficient in rho-O cells compared with HeLa cells. The residual amount of CPDs after 24-h repair was larger in rho-O cells than in HeLa cells where more than 90 % of CPDs were repaired by then. The non-repaired CPDs would lead to apoptosis in rho-O cells. These results suggest that mitochondrial genome may contribute to some ATP-dependent steps in nucletide excision repair by supplying sufficient ATP which is generated through a respiratory chain in mitochondria.

• Animal cells and systems
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• v.5 no.1
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• pp.77-83
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• 2001

The present study was conducted to elucidate whether the expression level of poly(ADP-ribose) polymerase (PARP) is related to the ultraviolet radiation (UV)-induced apoptosis. After treatment of the mammalian cell lines HeLa S3 and Chinese hamster ovary (CHO) with 50 J/m2 UV, induction of apoptosis was determined by several means during 24 h post-incubation. Incidence of apoptosis was much lower in CHO than HeLa S3 cells based on the percentage of apoptotic cells in terms of morphological changes in nucleus or direct counting of viable cells and qualitative or quantitative DNA fragmentation. Interestingly, when the expression level of PARP was measured by western blotting, the amounts of PARP that was retained at each time point inversely correlated with the incidences of apoptosis in these cells. Concomitant with generation of the 85 kDa fragment, 116 kDa PARP disappeared in HeLa S3 within 6 h after UV treatment, whereas a fair amounts of 116 kDa band was still retained in CHO cells at 36 h post-incubation. This inverse relationship was also observed in the adaptive response system, in which cells weve treated with a high dose of UV after pretreatment with a low dose. As expected, typical adaptive responses appeared in CHO cells but not in HeLa cells, showing greater cell viability and lesser DNA fragmentation. During the adaptive response in CHO cells, PARP was expressed at much higher level compared to the single, high dose-treated cells. Interestingly, even though PARP was induced at 6 h post-incubation In both cell types, its expression was more prominent in CHO cells. Thus, our data indicate that the retained level of intact PARP against UV damage inversely correlates with incidence of apoptosis in mammalian cells, and also suggest that a machinery to protect the PARP degradation against UV damage exists in CHO but not in HeLa S3 cells.

• Journal of dental hygiene science
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• v.2 no.1
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• pp.15-19
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• 2002

In this study, we investigated the cytotoxicity of ethyl acetate subfraction of Sophora flavescens Ait.(EASS) on cancer cells using MTT quantitative analysis. The EASS was cytotoxicity from the concentration of 6.25 g/ml to KB, B16, HeLa, and MCF-7 cancer cells and the cytotoxicity was significant, (p < 005) increased as the concentrations of EASS were increased, (12.5, 25, 50, 100 g/ml). The IC for KB, B16, HeLa, and MCF-7 were 56.58, 65.43, 83.95, and 106.65 g/ml, respectively. Conclusively, the EASS inhabited the growth of cancer cells and the order of potency of cytotoxicity was KB > B16 > HeLa > MCF-7.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5659-5663
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• 2012

To investigate the expression of hPOT1 in the HeLa cell line and screen point mutations of hpot1 in different tumor tissues a two step osmotic method was used to extract nuclear proteins. EMSA was performed to determine the expression of hPOT1 in the HeLa cell line. PCR was also employed to amplify the exon14 sequence of the hpot1 gene in various of cancer tissues. A SV gel and PCR clean-up system was performed to enrich PCR products. DNAStar was used to analyse the exon14 sequence of the hpot1 gene. hPOT1 was expressed in the HeLa cell line and the signal was gradually enhanced as the amount of extracted nuclear proteins increased. The DNA fragment of exon14 of hpot1 was successfully amplified in the HeLa cell line and all cancer tissues, point mutations being observed in 2 out of 3 cases of endometrial cancer (66.7%) despite the hpot1 sequence being highly conserved. However, the sequence of hpot1 exon14 do not demonstrate point mutations in most cancer tissues. Since hPOT1 was expressed in HeLa cell and the probability of gene point variants was obviously higher in endometrial cancer than other cancers, it may be involved in the pathogenesis of gynecological cancers, especially in cervix and endometrium.

• Molecules and Cells
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• v.23 no.1
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• pp.30-38
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• 2007

Dipyrithione (2, 2'-dithiobispyridine-1, 1'-dioxide, PTS2), a pyrithione derivate, is highly bactericidal and fungicidal. In this study we examined its apoptotic effect on HeLa cells. PTS2 induced HeLa cell death in a dose and time dependent manner. ERK1/2 and p38 were markedly activated, but little JNK1/2 activation was detected. Suppression of p38 activation by SB203580 reduced the extent of apoptosis of the HeLa cells and also prevented induction of p21, release of cytochrome c, and cleavage of caspase-3 and PARP. Inhibition of ERK1/2 with PD98059 increased apoptosis, indicating that ERK1/2 activation has an anti-apoptotic effect on PTS2-induced HeLa cell apoptosis. PTS2 also inhibited murine sarcoma 180 and hepatoma 22 tumor growth in an animal tumor model. Our findings indicate that PTS2 possesses anti-tumor activity, that caspase-3 and poly (ADP-ribose) polymerase (PARP) are involved in PTS2-induced HeLa cell apoptosis and that ERK1/2 and p38 have opposing effects on this apoptosis.

• Journal of KIISE
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• v.42 no.10
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• pp.1239-1246
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• 2015

Cell counting is extensively used to analyze cell growth in biomedical research, and as a result automated cell counting methods have been developed to provide a more convenient and means to analyze cell growth. However, there are still many challenges to improving the accuracy of the cell counting for cells that proliferate abnormally, divide rapidly, and cluster easily, such as cancer cells. In this paper, we present an automated cell counting method for HeLa cells, which are used as reference for cancer research. We recognize and classify the morphological conditions of the cells by using a cell segmentation algorithm based on cell membrane extraction, and we then apply a cell back-tracking algorithm to improve the cell counting accuracy in cell clusters that have indistinct cell boundary lines. The experimental results indicate that our proposed segmentation method can identify each of the cells more accurately when compared to existing methods and, consequently, can improve the cell counting accuracy.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.234-241
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• 2001

The C-terminal 393 bp region of the human interleukin-16 (IL-16) gene was cloned and expressed in E. coli along with mammalian cell lines. Recombinant IL-16 expressed from E. coli was 22 kDa on SDS-PAGE and showed 260% of chemoattractant activity at a concentration of $0.1\;{\mu}g/ml$. HeLa, COS, and Neuro-2a cells were transduced by recombinant retrovirus vector pLNC/IL-16/IRES/TK and the intracellular and secreted amounts of IL-16 produced by HeLa/IL-16/TK, COS/IL-16/TK, and Neuro-2a/IL-16/TK cells were determined by enzyme-linked immunosorbent assay (ELISA). HeLa/IL-16/TK $(1{\times}10^5)$ and COS/IL-16/TK $(1{\times}10^5)$ cells secreted 36.1 and 13.3 ng of IL-16 for 48 h, respectively. Forty-nine ng and 86.4 ng of IL-16 remained in the cell lysates of HeLa/IL-16/TK and COS/IL-16/TK. Intracellular and secreted amounts of IL-16 from Neuro-2a/IL-16/TK $(5{\times}10^5)$ cells during 24 h cultivation were 50 ng and 3.3 ng, respectively. Also, HeLa and COS cells wee stably transfected with mammalian expression vector pCRIII/IL-16. Both culture media and cell lysates prepared from HeLa/IL-16 cells and COS/IL-16 cells showed chemoattractant activity ranging from 190% to 460% as compared to the control experiment. Expression of the herpes simplex virus thymidine kinase (HSV0tk) gene in pLNC/IL-16/ IRES/TK bicistronic retroviral expression vector was verified by performing a genciclovir (GCV) sensitivity assay. Finally, IL-16 repressed Tat-transactivated human immunodeficiency virus type 1 long terminal repeat (HIV-1 LTR) promoter activity.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.2
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• pp.139-154
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• 2007

Purpose: This study examined the Cell differentiation and the anti-oxidative effect of Dioscoreae Rhizoma on HeLa cells. We are interested in whether Dioscoreae Rhizoma is capable of causing apoptosis processes on HeLa cell, and whether cotreatment of NCS with Dioscoreae Rhizoma reduces cell viability. Methods: We used aqueous extract to treat HeLa cell with different concentrations treated with a water or a MeOH extract of Dioscoreae Rhizoma (0, x10, x20, x40, x80). The MTT (3, (4, 5-dimethyl-thiazol) 2, 5-diphenyl-tetraxolium bromide) reduction assay was employed to quantify the differences in cell activity and viability. Cells were stained with DAPI and visualized by fluorescent Microscope. The caspase-3, Bcl-2, PARP, p53 expression level was monitored using western-blotting techniques. The patterns of the changes in expression were scanned and analyzed. Results: The survival rate of cells treated with Dioscoreae Rhizoma extracts increased by 20% at specific concentration. The other side Dioscoreae Rhizoma extracts induced apoptotic features including chromatin condensation and fragmentation. And Dioscoreae Rhizoma extracts increased the expression of caspase-3, p53 and the cleavage of PARP protein. However, co-treatment with Dioscoreae Rhizoma with NCS attenuated the activations of p53 and PARP protein that were mediated by NCS treatment alone. This is indicated Dioscoreae batatas extracts attenuated cytotoxicity induced by oxidative agents including NCS. Conclusion: Our results suggest Dioscoreae Rhizoma extracts induce cell differentiation or apoptosis connected with concentration. Further elucidation of concentration of Dioscoreae Rhizoma awaits many other biochemical investigative studies.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.276-280
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• 2003

Background: Peroxidases (Prx) of the peroxiredoxin family reduce hydrogen peroxide and alkyl hydroperoxides to water and alcohol respectively. Hydrogen peroxide is implicated as an intracellular messenger in various cellular responses such as proliferation and differentiation. And Prx I activity is regulated by Cdc-2 mediated phosphorylation. This work was undertaken to investigate the proliferation role of peroxiredoxin III as a member of Prx family in Prx III overexpressed HeLa cell line. Methods: To provide further evidence of proliferation, we selected Prx III stably expressed HeLa Tet-off cell lines. Cell proliferation was examined by using proliferation reagent WST-1 in the presence or absence of doxycycline. Prx III, 2-cys Prx enzymes exist as homodimer. The activation of Prx III heterodimer with induced and endogenous Prx III was examined by immunoprecipitation. Results: Immunoprecipitation analysis of the induced and endogenous Prx III with anti-myc showed that the induced wild type (WT) and dominant negative (DN) Prx III from HeLa Prx III Tet-off stable cell heterodimerized with endogenous Prx III each other. And the expression level of induced Prx III was examined after addition of doxycycline. By 72 hr, the expression level of induced Prx III was diminished gradually and the half-life of the induced wild type Prx III was approximately 17 hr. The proliferation experiment demonstrated that the relative proliferation value of induced and endogenous WT Prx III stable cell has no changes but the DN Prx III induced HeLa Tet-off stable cells were lower than endogenous Prx III. Conclusion: In conclusion, the HeLa dominant negative Prx III Tet-off stable cells were decreased the proliferation.