Cervical Adenocarcinoma HeLa Cell Line Research Articles

Assessment of the biological activity of Marrubium friwaldskyanum Boiss. (Lamiaceae)

Present scientific evidences about the biological activity and potential medical application of extracts derived from Marrubium friwaldskyanum Boiss. are limited. Therefore, our study was undertaken to define several main characteristics in this regard – in vitro cytotoxicity and antitumor properties, antibacterial activity and immunomodulatory potential. Extracts were obtained from different aerial parts of Marrubium friwaldskyanum – stems, leaves and flowers. The in vitro cytotoxicity and antitumor activity of the samples were evaluated by tetrazolium salt reduction tests and Neutral red uptake assays using four human cell lines (a normal fibroblastic and three adenocarcinoma cell lines/A549, HeLa, HT-29/) and by experiments with HT-29 tumor spheroids. Antibacterial activity toward Gram-negative (Escherichia coli) and Gram-positive (Bacillus cereus) species was assessed based on estimation of minimal inhibitory and minimal bactericidal concentrations as well as longitudinal studies on bacterial viability. Ex vivo assays with normal leukocytes were performed to define potential immunomodulatory activity of the extracts. Our results demonstrated selective antitumor activity of the extracts directed against colon adenocarcinoma HT-29 cells and cervical adenocarcinoma HeLa cell line. Metabolic activity of A549 lung adenocarcinoma cells was affected only by the sample derived from flowers. M. friwaldskyanum leaf and flower extracts showed the highest activity, which included reduction of HT-29 tumor spheroid growth and viability. The studied samples exhibited antibacterial activity against both bacterial species tested. Treatment with M. friwaldskyanum extracts affected specific leukocyte populations (HLA+, CD19+, CD11b+, CD25+ cells). These results demonstrate for the first time complex biological effects of extracts derived from M. friwaldskyanum and their potential to serve as a source of valuable compounds for the pharmaceutical industry.

Antioxidant and Antitumor Potential of Micropropagated Balkan Endemic Sideritis scardica Griseb

Sideritis scardica Griseb. is a critically endangered Balkan endemic species, known for its antioxidant, neuroprotective and anti-inflammatory properties. The aim of the present study was to detail an efficient protocol for the micropropagation of S. scardica. In vitro cultures were initiated from the shoot tips of 40 days-old in vivo seedlings and the effects of different plant growth regulator treatments were examined. A Murashige and Skoog nutrient medium (MS) containing 1 mg/L zeatin and 0.1 mg/L indole-3-acetic acid (IAA) proved to be the most efficient for shoot multiplication as it produced quality, vigorous shoots with a mean number of six shoots per explant. For the first time, the antioxidant and antitumor activities of extracts from in vitro-obtained plants were evaluated. In vitro cultivated plants grown in the field revealed a higher total polyphenol content (3929.1 ± 112.2 mg GAE/100 g vs. 3563.5 ± 52.8 mg GAE/100 g) and higher ORAC antioxidant activity (1211.6 ± 27.3 µmol TE/g vs. 939.9 ± 52.4 µmol TE/g) than in situ cultivated plants. A comparison of the antitumor activities of extracts from in vitro propagated shoots, field-grown in vitro-obtained plants and in situ plants on HeLa (cervical adenocarcinoma), HT-29 (colorectal adenocarcinoma) and MCF-7 (breast cancer) human cancer cell lines showed that in vitro propagated shoots had a significant concentration-dependent cytotoxic effect on the cervical adenocarcinoma cell line HeLa, while the field-grown in vitro-obtained and in situ-collected samples induced the highest reduction in the viability of the mammary carcinoma cell line MCF-7. In both cases, the cells of the control non-tumor cell line, BALB/3T3, were significantly less affected. The results showed that the in vitro multiplication protocol ensured the obtainment of numerous plants with antioxidant and antitumor potential.

Cytotoxic activity of Galantamine hydrobromide against HeLa cell line

Cytotoxic activity of Galantamine HBr against human cervical adenocarcinoma cell line HeLa in different concentrations (1.875 μМ ÷ 30 μМ) was evaluated. Inhibition of HeLa cell growth after treatment with Galantamine HBr and index of cell viability were determined. From the experimental results was proven that the drug exerts cytotoxic activity towards HeLa cell line, with antiproliferative activity presented as the value of IC50 = 30 μM ± 0.22.

CDK6 increases glycolysis and suppresses autophagy by mTORC1-HK2 pathway activation in cervical cancer cells

ABSTRACT Cervical carcinoma is a leading malignant tumor among women worldwide, characterized by the dysregulation of cell cycle. Cyclin-dependent kinase 6 (CDK6) plays important roles in the cell cycle progression, cell differentiation, and tumorigenesis. However, the role of CDK6 in cervical cancer remains controversial. Here, we found that loss of CDK6 in cervical adenocarcinoma HeLa cell line inhibited cell proliferation but induced apoptosis as well as autophagy, accompanied by attenuated expression of mammalian target of rapamycin complex 1 (mTORC1) and hexokinase 2 (HK2), reduced glycolysis, and production of protein, nucleotide, and lipid. Similarly, we showed that CDK6 knockout inhibited the survival of CDK6-high CaSki but not CDK6-low SiHa cervical cancer cells by regulation of glycolysis and autophagy process. Collectively, our studies indicate that CDK6 is a critical regulator of human cervical cancer cells, especially with high CDK6 level, through its ability to regulate cellular apoptosis and metabolism. Thus, inhibition of CDK6 kinase activity could be a powerful therapeutic avenue used to treat cervical cancers.

Antiproliferative Activity of Cissus quadrangularis L. Extract Against Human Cervical Cancer Cells: In Vitro and In Silico Analysis.

Cervical cancer is the second leading cause of cancer in women, which necessitates safe and potential therapeutic agents. This study was designed to investigate the antiproliferative effect of ethanolic extract of Cissus quadrangularis L. (CQ) against human cervical adenocarcinoma HeLa cell line and in silico analysis of selected active agents against apoptosis executioner enzyme caspase-3. Cell viability was analyzed in HeLa cells at different concentrations (25-300 μg/ml) of CQ extract. Reactive oxygen species (ROS) generation, cellular apoptosis, cell cycle analysis and caspases-3 activation were evaluated. In silico, structure-based virtual screening analysis was carried out using AutoDock Vina and iGEMDOCK. Cell viability of HeLa cells was reduced significantly (p < 0.05) in a dose-dependent manner, however, CQ extract showed non-toxic to normal kidney epithelial NRK-52E cells. CQ extract induced the intracellular ROS level, nuclear condensation and reduced the mitochondrial membrane potential (MMP) with the induction of annexin V-FITC positive cells. CQ extract arrested cells in G0/G1 and G2/M checkpoints and activated caspase-3 activity significantly in HeLa cells. The molecular docking study showed a strong binding affinity of CQ phytocomponents against the caspase-3 (PDB ID: 1GFW) protein of human apoptosis. PASS analyses of selected active components using Lipinski's Rule of five showed promising results. Further, drug-likeness and toxicity assessment using OSIRIS Data Warrior V5.2.1 software exhibited the feasibility of phytocomponents as drug candidates with no predicted toxicity. This study suggested that active constituents in CQ extract can be considered as potential chemotherapeutic candidates in the management of cervical cancer.

Eulophia macrobulbon – an orchid with significant anti-inflammatory and antioxidant effect and anticancerogenic potential exerted by its root extract

BackgroundThe Orchidaceae family is one of the largest families of flowering plants. Orchids are widely used for the traditional herbal medicine, acting as aphrodisiac, antisepic, antimicrobial, anti-cancer agent, etc. PurposeThis study was designed to elucidate the anti-inflammatory, antioxidant and cytotoxic potential of a 50% ethanolic extract of Eulophia macrobulbon roots (EME) in vitro, an orchid growing in Southern Asia. Furthermore, the main active compounds were isolated, and the bioactivity of the single constituents was determined. MethodsThe anti-inflammatory activity of EME and its compounds was evaluated by the secretion of pro- and anti-inflammatory cytokines and by the expression of inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated macrophage model, as determined by an enzyme linked immunosorbent assay (ELISA) and Western blot. Antioxidant activity was assessed using a DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) photometric assay. Cytotoxic effects were determined using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-assay. ResultsEME and its compounds significantly reduced the production of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), the expression of iNOS and subsequently increased the production of the anti-inflammatory cytokine interleukin 10 (IL-10) in LPS-stimulated macrophages. Additionally it could be demonstrated that EME is rich in radical scavengers. Furthermore, EME and its components showed notable cytotoxic effects on the human cervical adenocarcinoma cell line HeLa, the human colorectal adenocarcinoma cell line CaCo-2 and the human breast adenocarcinoma cell line MCF-7. The most active constituents were identified as 4-methoxy-9,10-dihydro-2,7-phenanthrenediol (8), 4-methoxy-2,7-phenanthrenediol (9), 1,5-dimethoxy-2,7-phenanthrenediol (10), 1,5,7-trimethoxy-2,6-phenanthrenediol (11), 1-(4-hydroxybenzyl)-4,8-dimethoxy-2,7-phenanthrenediol (15). ConclusionBased on this data, EME provides various beneficial anti-inflammatory, antioxidant and cytotoxic attributes and may be used as herbal remedy in the pharmaceutical or food industries.

Methotrexate induces DNA damage and inhibits homologous recombination repair in choriocarcinoma cells

ObjectiveThe objective of this study was to investigate the mechanism of sensitivity to methotrexate (MTX) in human choriocarcinoma cells regarding DNA damage response.MethodsTwo choriocarcinoma cancer cell lines, JAR and JEG-3, were utilized in this study. An MTX-sensitive osteosarcoma cell line MG63, an MTX-resistant epithelial ovarian cancer cell line A2780 and an MTX-resistant cervical adenocarcinoma cell line Hela served as controls. Cell viability assay was carried out to assess MTX sensitivity of cell lines. MTX-induced DNA damage was evaluated by comet assay. Quantitative reverse transcription polymerase chain reaction was used to detect the mRNA levels of BRCA1, BRCA2, RAD51 and RAD52. The protein levels of γH2AX, RAD 51 and p53 were analyzed by Western blot.ResultsRemarkable DNA strand breaks were observed in MTX-sensitive cell lines (JAR, JEG-3 and MG63) but not in MTX-resistant cancer cells (A2780 and Hela) after 48 h of MTX treatment. Only in the choriocarcinoma cells, the expression of homologous recombination (HR) repair gene RAD51 was dramatically suppressed by MTX in a dose- and time-dependent manner, accompanied with the increase in p53.ConclusionThe MTX-induced DNA strand breaks accompanied by deficiencies in HR repair may contribute to the hypersensitivity to chemotherapy in choriocarcinoma.

In vitro evaluation of cytotoxic activity of Trigonella foenum-graecum on human cervical cancer HeLa cells

Trigonella foenum-graecum L. (fenugreek) is a plant of the Fabaceae family. The species contains steroidal saponins, flavonoids, polysaccharides and phenolic acids, which are pharmacological active compounds with anti-inflammatory, antioxidant and hypoglycemic properties. This study reports on the evaluation of cytotoxic effects of the plant methanolic and aqueous extracts, flavonoid fraction and isolated flavonoids -orientin, isoorientin, vicenin-1, -2, and -3- on human cervical adenocarcinoma cell line HeLa. The antiproliferative activity was estimated on the cells with MTT assay and the xCELLigence system (Roche), which allows continuous monitoring of cell viability. The obtained data show that both methanolic and aqueous extracts, as well as the flavonoid fraction have significant cytotoxic activity on the cells with IC50 values of 13.47 ± 0.62 µg/mL, 17.43 ± 0.30 µg/mL and 3.91 ± 0.03 µg/mL, respectively. The flavonoids did not exhibit activity on the cells (IC50> 50 µg/mL). Additionally, HeLa cells treated with the fraction were stained with annexin V and analyzed on the Muse Cell Analyzer (Merck Millipore). The flow cytometry analysis shows that the fraction induces apoptosis in the tested cells in a dose-dependent manner. To confirm induction of apoptosis in HeLa cells incubated with the fraction, we stained the cells with Hoechst 33342 dye and observed the chromatin condensation and nuclear fragmentation in the cells.

Pennogenyl Saponins from Paris quadrifolia L. Induce Extrinsic and Intrinsic Pathway of Apoptosis in Human Cervical Cancer HeLa Cells.

Pennogenyl saponins are the active compounds of large number of plant species and consequently many polyherbal formulations. Hence, great interest has been shown in their characterization and in the investigation of their pharmacological and biological properties, especially anticancer. This present study reports on the evaluation of cytotoxic effects and explanation of the molecular mechanisms of action of the two pennogenyl saponins (PS 1 and PS 2) isolated from Paris quadrifolia L. rhizomes on human cervical adenocarcinoma cell line HeLa. To determine the viability of the cells treated with the compounds we used real-time cell proliferation analysis and found that the pennogenyl saponins PS 1 and PS 2 strongly inhibited the tumor cells growth with IC50 values of 1.11 ± 0.04 μg/ml and 0.87 ± 0.05 μg/ml, respectively. The flow cytometry analysis indicated that the two compounds induced apoptosis in a dose-dependent manner and decreased mitochondrial membrane potential in HeLa cells in the early stage of apoptosis. Quantitative PCR and Western Blot analysis showed that the two saponins significantly increased mRNA expression of FADD and BID as well as induced caspase-8 via increased of procaspase-8 processing in the treated cells. The results of this study suggest that both the extrinsic death receptor and intrinsic mitochondrial pathways are involved in the programmed cell death.

PEGylated graphene oxide as a nanocarrier for podophyllotoxin

Graphene, a two-dimensional nanomaterial, has become a hot spot of research at the interface of nanotechnology and biomedicine. In this study, the oxidized form of graphene, graphene oxide (GO), was functionalized with 6-armed polyethylene glycol (PEG), which rendered it stable and biocompatible in physiological solution. The successful synthesis of PEGylated graphene oxide (GO-PEG) nanocarrier with low toxicity was confirmed by UV–Vis spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy, and thermogravimetric analysis. By dynamic light scattering (DLS), the size distribution of the nanoparticles were shown to be 60–200 nm. Furthermore, a complex by loading an aromatic anticancer compound, podophyllotoxin (PPT), onto GO-PEG (GO-PEG/PPT) via π–π stacking and hydrophobic interactions was investigated. It was demonstrated that GO-PEG/PPT showed remarkably high cytotoxicity compared to free PPT in both the human cervical adenocarcinoma HeLa cell line and human hepatoma SMMC-7721 cell line. The loading and delivery of anticancer drugs using this kind of graphene-based nanocarrier may find potential application in biomedicine.

Synthesis of novel pyrazolo[3,4-d]pyrimidinone derivatives as cytotoxic inhibitors

Various α-fonctionalized iminoethers 2 were easily prepared from ethyl 5-amino-3-substituted-1-phenyl-1H-pyrazole-4-carboxylate 1. The reaction of iminoethers 2 with ammonia afforded 3-substitued-1-phenyl-1H-pyrazolo[3,4-d] pyrimidin-4(5H)-ones 3 which were also synthesized by the addition of formamide to ethyl 5-amino-3-substituted-1-phenyl-1H-pyrazole-4-carboxylate 1. The 5-amino-3-substitued-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones 4 were obtained from hydrazonolysis of iminoethers 2. Otherwise, the condensation of these intermediates 2 with a series of some primary amines and hydroxylamine led respectively, to the corresponding 3,5-disubstitued-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-ones 5 and the 3-substitued-5-hydroxy-1-phenyl-1H-pyrazolo[3,4-d] pyrimidin-4-(5H)-ones 6. The synthesized compounds 1-6 were completely characterized by 1H NMR, 13C NMR, IR and HRMS. Some synthesized compounds were evaluated for their cytotoxic effect using the Human cervical adenocarcinoma Hela cell line.

Poly(ethylene glycol)-Modified PAMAM-Fe3O4-Doxorubicin Triads with the Potential for Improved Therapeutic Efficacy: Generation-Dependent Increased Drug Loading and Retention at Neutral pH and Increased Release at Acidic pH

Polyamidoamine (PAMAM) dendrimer-coated magnetic nanoparticles are a promising drug-delivery system that can enhance the therapeutic effects of chemotherapy drugs, such as doxorubicin (DOX), with minimized side effects. This work explores the optimization of the potential therapeutic efficiency of PAMAM-Fe3O4-DOX triads. Different generations (G3, G5, and G6) of PAMAMs were synthesized and modified with poly(ethylene glycol) (PEG) and then used to encapsulate glutamic acid-modified Fe3O4 nanoparticles. The Fe3O4-dendrimer carriers (Fe3O4-DGx where x = the generation 3, 5, or 6 of dendrimers) were electrostatically conjugated with drug DOX. The loading and releasing efficiencies of DOX increased with the PAMAM generation from 3 to 6. The loading efficiencies of DOX molecules were 87, 93, and 96% for generations 3, 5, and 6, respectively. At pH 5, the DOX release efficiencies within 24 h were approximately 60, 68, and 80% for generations 3, 5, and 6, respectively. At pH 7.4, the DOX releasing efficiency was as low as ∼ 15%. Compared to the negative control, the PAMAM-Fe3O4-DOX triads showed only mild toxicity against human cervical adenocarcinoma cell line HeLa at pH 7.4, which indicated that DOX can be fairly benignly carried and sparingly released until PAMAM-Fe3O4-DOX is taken up into the cell.

Inhibition of Signal Transducer and Activator of Transcription 3 and Cyclooxygenase-2 Is Involved in Radiosensitization of Cepharanthine in HeLa Cells

To investigate the radiosensitizing effects of cepharanthine (CEP) in the human cervical adenocarcinoma HeLa cell line and to examine the underlying mechanisms. Survival of HeLa cells after treatment with or without ionizing radiation (IR) and CEP administration was investigated. MTT assays and apoptosis analysis were used to assess cytotoxicity. Nude mouse xenografts were established to evaluate the antitumor effects of CEP and IR in vivo. Expression of signal transducer and activator of transcription 3 (STAT3) and its downstream signaling molecules as well as cyclooxygenase-2 (COX-2) were examined by Western blot analysis. Clonogenic assays showed that treatment with CEP and IR resulted in significant radiosensitization. Cepharanthine and IR treatment achieved maximum cytotoxic effects on HeLa cells with regard to apoptosis induction. Cepharanthine efficiently decreased IR-induced STAT3 and COX-2 activation. The STAT3 target genes, including the antiapoptotic Bcl-2 and the cell cycle regulator c-Myc, were decreased concomitantly. In vivo administration of CEP (20 mg/kg every 2 days) combined with radiation in HeLa xenografts enhanced tumor growth delay and apoptosis (indicated by activated caspase-3 Western blot analysis), with reduced expression of STAT3, Bcl-2, c-Myc, and COX-2. Cepharanthine was shown to induce radiation sensitization in HeLa cells in vitro and in vivo. The inhibitory effects of CEP on STAT3 signaling pathway and COX-2 help us to better understand the radiosensitization of CEP.

Loss of VOPP1 overexpression in squamous carcinoma cells induces apoptosis through oxidative cellular injury

The vesicular overexpressed in cancer prosurvival protein 1 (VOPP1) gene product (previously known as GASP and ECOP) has a poorly characterized functional role in cancer cells, although its expression levels are known to be elevated in many cancer types. To determine the role that VOPP1 has in human squamous cell carcinoma (SCC), a series of siRNA-mediated expression knockdown experiments were performed in carcinoma-derived model systems with confirmed endogenous VOPP1 overexpression (three SCC-derived cell lines: SCC-9, FaDu, and H2170, as well as the cervical adenocarcinoma HeLa cell line, which has been examined in relevant previous reports). The data indicate that VOPP1 knockdown induces cell death at 72 h post-transfection and this is caused by the induction of apoptosis via the intrinsic pathway. Analysis of microarray gene expression profiling showed that genes whose expression was affected by VOPP1 knockdown exhibited enrichment in annotations of oxidative stress and mitochondrial dysfunction. Reporters of reactive oxygen species (ROS) and mitochondrial membrane potential show that ROS levels become elevated and mitochondrial dysfunction occurs with VOPP1 knockdown at time points before the activation of effector caspases and cell death seen at later time points. Furthermore, the introduction of the antioxidant N-acetyl cysteine was able to abrogate the induction of apoptosis observed with VOPP1 knockdown in a dose-responsive manner. Reporter constructs for NF-κB-mediated transcription are not affected in SCC cell lines by VOPP1 knockdown. Taken together, these data support the hypothesis that VOPP1 overexpression in cancer participates in the control of the intracellular redox state, and that its loss leads to oxidative cellular injury leading to cell death by the intrinsic apoptotic pathway.

Comparative analysis of the nucleosome structure of cell nuclei by small-angle neutron scattering

The nucleosome structure in native nuclei of normal (chicken erythrocyte and rat leukocyte nuclei) and anomalously proliferating (the human cervical adenocarcinoma cell line HeLa and the Chinese hamster fibroblast cell line A238) cells has been investigated using small-angle neutron scattering. The experimental results obtained allow one to make the inference that the parameters of the nucleosome structure for the chicken erythrocyte and rat leukocyte nuclei (on average over the nucleus) are close to the universally accepted values and that the distance distribution function is bimodal. The bimodality of the distance distribution function reflects a narrow distribution of distances between nucleosomes (on average over the nucleus) at the fibril level of the chromatin organization. The histone core of the nucleosome structure in the nuclei of the HeLa and A238 cells (on average over the nucleus) is considerably less compact than that in the chicken erythrocyte and rat leukocyte nuclei, and the distance distribution function does not exhibit indications of the bimodality.

CCDC132 is highly expressed in atopic dermatitis T cells

The analysis of genes preferentially expressed in the peripheral blood cells of atopic dermatitis patients may provide information on the molecular pathogenesis of the disease. We employed differential display PCR to clone a new gene (AB100163) with 99% homology to coiled-coil domain containing 132, transcript variant 1 (CCDC132) (NM_017667) (aliases, FLJ20097, FLJ23581, KIAA1861 and MGC176659). Full-length CCDC132 of approximately 4 kbp encodes mRNA expressed in almost all tissues, in particular brain tissue and skeletal muscle. A homologous gene has also been identified in mice. Using Western blot analysis, 111 kDa CCDC132 protein was detected in two human T-cell lines, MOLT-4 and Jurkat, and in the human cervical adenocarcinoma cell line HeLa. Quantitative RT-PCR revealed transcription levels of CCDC132 in the T cells of atopic dermatitis patients to be higher than in those of normal individuals. This suggests that changes in CCDC132 expression may be involved in the course of atopic dermatitis.

Vitamin E (α-tocopherol) enhances the PDT action of hematoporphyrin derivatives on cervical cancer cells

Objective: The effect of antioxidant vitamin E (VE) on PDT (a mainly reactive oxygen species-driven process) has in the past shown contradicting results. Hence, we studied the effect of different concentrations and different incubation periods of VE on the PDT cytotoxicity of the cervical adenocarcinoma HeLa cell line. Materials and methods: HeLa cells were incubated with 25mg/ml of hematoporphyrin derivatives (HpD) for 25 min (1st PDT regimen) or 24 h (2nd PDT regimen), then irradiated with visible light (total light dose of 10 J/cm 2 ) either with or without different concentrations of VE (1–1000mM) which had been incubated with the cells for 1 h or 24 h prior to PDT. After irradiation, viability was measured using MTT assay. Results: The results obtained showed that PDT is effective against cervical cancer cells. Incubation of HpD for 24 h leads to improved PDT action. Higher concentrations of VE incubated in HeLa cells for 1 h before the 2nd PDT regimen significantly enhanced cytotoxicity of PDT and the maximal enhancement was at 1000mM of VE. The cytotoxic effect of VE on HeLa cells after incubation for 24 h before PDT is enhanced by the PDT action. Conclusion: In conclusion 1000mM of VE can be used 1 h before PDT to enhance its effect on cervical adenocarcinoma, a disease which is steadily increasing in young women. It is well-known that the cervical adenocarcinoma is resistant to anticancer agents and radiotherapy and it was previously considered to be HpD-PDT resistant.

On the mechanism of phenotypic conversion of human cervical adenocarcinoma HeLa cells surviving infection by influenza B virus: Potential implications for biological management of adenocarcinomas

We infected HeLa cells with low (10 −9 units), medium (10 −6 units), and high (10 −2 units) influenza B titers and compared the resulting human papilloma virus (HPV), retinoic acid receptor α subunit (RAR α) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA content of surviving infected hosts with that of their uninfected precursors by semi-quantitative reverse transcriptase/polymerase chain reaction amplification (RT/PCR). This comparison revealed a moderate and drastic dependence of HPV and RAR α mRNA content, respectively, but a complete independence of GAPDH mRNA expression on viral titer. A mechanism of adoptive replacement of tolerable cellular with viral gene expression was proposed to explain these findings. We conclude that the reported ability of influenza B viruses to specifically target and eliminate the cervical adenocarcinoma HeLa cell line studied may find practical applications in biological cancer management.

Characterization and localization of mitochondrial oligopeptidase (MOP) (EC 3.4.24.16) activity in the human cervical adenocarcinoma cell line HeLa.

In this study we describe the partial purification and characterization of the HeLa cell oligopeptidase M or endopeptidase 3.4.24.16. The HeLa enzyme was isolated initially by its ability to hydrolyse a nonapeptide substrate (P9) which was cognate to the N-terminal cleavage site of preproTGF alpha. The enzyme was shown to be a metalloprotease as it was inhibited by Zn(2+)-chelating agents and DTT, and had an approximate molecular weight of 55-63 kD determined by gel filtration. Neurotensin, dynorphin A1-17 and GnRH1-9 were rapidly degraded by the enzyme while GnRH1-10 and somatostatin were not. Neurotensin was cleaved at the Pro10-Tyr11 bond, leading to the formation of neurotensin (1-10) and neurotensin (11-13). The K(m) for neurotensin cleavage was 7 microM and the Ki for the specific 24.16 dipeptide inhibitor (Pro-ile) was 140 microM which were similar to those observed from the human brain enzyme [Vincent et al. (1996): Brain Res 709:51-58]. Through the use of specific antibodies, the purified HeLa enzyme was shown to be oligopeptidase M. This enzyme and its closely related family member thimet oligopeptidase were shown to co-elute during the isolation procedure but were finally separated using a MonoQ column. Oligopeptidase M is located mainly in mitochondria though it was detected on the plasma membrane in an inactive form. The results obtained demonstrate the first recorded instance of this enzyme in human tissue cultured cells, and raise the issue of its function therein.