Cervical Fibroblasts Research Articles

Predominant Contribution of IFN-.BETA. Expression to Apoptosis Induction in Human Uterine Cervical Fibroblast Cells by Influenza-Virus Infection

We have been investigating an apoptosis induction in human fetal membrane cells by influenza virus (IV) infection and the contribution of apoptosis induction to the viral infection-defense response between a fetus and the maternal body. For studying any role of uterine cells in the anti-viral response, we investigated the molecular mechanism of the apoptotic induction in human uterine cervical fibroblast cell line (HCF) by IV infection. IV type A and B infection induced DNA fragmentation in HCF. In IV-infected HCF, gene mRNA expression levels of interleukine (IL)-1beta, IL-6, tumor necrosis factor (TNF) alpha, Fas ligand, interferon regulatory factor (IRF)-1, interferon (IFN) alpha and IFN beta increased as compared with those in mock treatment cells, and the induction of mRNAs for double stranded RNA dependent protein kinase (PKR), indolamine 2,3-deoxygenase (IDO) and 2'-5' oligoadenylate synthetase (2-5 OAS) were indicated, which had a role for a host defense response induced by IFN-beta. The amount of IFN-beta protein increased by IV-infection, and DNA fragmentation was inhibited with anti-IFN-beta antibody and PKR inhibitor (2-aminopurine). Furthermore, a synthetic double stranded RNA, poly I : C, could induce almost the same phenomena as that induced by virus infection. We conclude that IV-infection induces the apoptosis in HCF cells through the IFN-beta expression regulated by double stranded RNA and IRF-1 induction, and suggest that the IFN-beta induction may be the predominant contribution to the IV infection induced HCF apoptosis.

Tumor–stromal cell contact promotes invasion of human uterine cervical carcinoma cells by augmenting the expression and activation of stromal matrix metalloproteinases

Objective. The augmentation of the expression and activation of matrix metalloproteinases (MMPs) is associated with tumor invasion and metastasis. In addition, tumor–stromal cell contact provides a crucial signal for regulating the pericellular proteolysis for the progression of tumor invasiveness. The present study evaluates the regulation of the expression and activation of MMPs and tissue inhibitors of metalloproteinases (TIMPs) by tumor–stromal cell contact in an in vitro co-culture model of human uterine cervical carcinoma cells and human uterine cervical fibroblasts. Methods. When human uterine cervical carcinoma SKG-II cells were co-cultured with human uterine cervical fibroblasts (HUCFs), the invasive activity of SKG-II cells was analyzed using an in vitro invasion assay using Matrigel. The production, mRNA expression and activation of MMPs and TIMPs were monitored by Western blot and Northern blot analyses and gelatin zymography. Results. SKG-II cells, which constitutively produced membrane-type 1 MMP (MT1-MMP) and a trace of proMMP-2 but neither TIMP-1 nor TIMP-2, showed poor invasiveness in vitro. Upon co-culturing with HUCFs, SKG-II cells were found to transform to the invasive phenotype by enhancing the production and mRNA expression of tumoral MT1-MMP. In addition, a sequential increase in the activation of fibroblast proMMP-2 was observed along with the formation of an MT1-MMP-TIMP-2-proMMP-2 complex on the tumor cell surface. Furthermore, the production and gene expression of fibroblast proMMP-1 and proMMP-3 were augmented under co-culture conditions, whereas mRNA expression of proMMP-2, TIMP-1 and TIMP-2 was unchanged. Moreover, we demonstrated the partial involvement of tumor-cell-derived soluble factors in the augmentation of the production of proMMP-1 and proMMP-3 in HUCFs. However, anti-integrin β1 and β3 antibodies failed to abolish the augmentation of fibroblast proMMP-3 production and proMMP-2 activation in the co-culture. Conclusion. Cell–cell contact between cervical carcinoma cells and peripheral stromal fibroblasts augments the production and activation of MMPs, and therefore the subsequent imbalance between MMPs and TIMPs may result in the progression of invasiveness of cervical carcinoma cells in vivo.

Synthesis, Structural Studies, and Biological Evaluation of Some Purine Substituted 1-Aminocyclopropane-1-carboxylic Acids and 1-Amino-1-hydroxymethylcyclopropanes

The novel purine derivatives of 1-aminocyclopropane-1-carboxylic acid (8 and 9) and 1-amino-1-hydroxymethylcyclopropane (12 and 13) with methylene spacer between the base and the cyclopropane ring were prepared by multistep synthetic route involving alkylation of adenine and 6-(N-pyrrolyl)purine with 2-hydroxymethyl-1-aminocyclopropane-1-carboxylic acid derivative 3 as a key reaction. All novel compounds were racemic. The N-9 substitution of the purine ring and the Z-configuration of the cyclopropane ring in 4–13 were deduced from their 1H and 13C NMR spectra by analyses of chemical shifts, H-H coupling constants and connectivities in two-dimensional homo- and heteronuclear correlation spectra. An unequivocal proof of the stereostructure of 1, 4 and 5 was obtained by their X-ray structure analysis. The novel compounds were evaluated on cytostatic and antiviral activities in several cell lines. The 6-(N-pyrrolyl)purine derivative of 1,2-aminocyclopropane alcohol 12 exhibited a more pronounced inhibitory activity against the proliferation of cervical carcinoma (HeLa) and human fibroblast (WI-38) cells than other types of tumor cell lines. None of the compounds showed inhibitory activities against cytomegalovirus, varicella-zoster virus or other viruses.

Antitumor principle constituents of Myrica rubra Var. acuminata.

Myrica rubra var. acuminata is a native shrub widely distributed and used as folk medicine in Taiwan for stomach disorders and diarrhea. Column chromatography combined with cytotoxic bioassay-guided fractionation was performed to isolate the antitumor principles from fresh leaves of M. rubravar. acuminata. The 20% MeOH eluate fraction of M. rubra var. acuminata inhibited the viability of HeLa and P-388 cells in an in vitro assay and an in vivo P-388 tumor-bearing CDF(1) mouse model. The percent increase in life span (%ILS) of 20% MeOH eluate fraction was greater than 125%. (-)-Epigallocatechin 3-O-gallate (1) and prodelphinidin A-2,3'-O-gallate (2) were isolated from D-20 as the antitumor principle components. Both compounds can inhibit the growth of HeLa cells, but 1 had lower cytotoxic effects in normal cervical fibroblasts than did 2. Moreover, pretreatment with a caspase-3 specific inhibitor prevented 1- and 2-induced poly(ADP-ribose) polymerase cleavage. In view of these results, we suggest that 1 and 2 can induce apoptosis in HeLa cells and that activation of caspase-3 may provide a mechanistic explanation for their cytotoxic effects. Therefore, we suggest that the 20% MeOH eluate fraction extract is good for health and that M. rubra var. acuminata is an economically valuable plant.

Interleukin-1beta induces glycosaminoglycan synthesis via the prostaglandin E2 pathway in cultured human cervical fibroblasts.

The aim of this study was to identify, in cultured human cervical fibroblasts, the mechanisms by which interleukin (IL)-1beta induces the synthesis of glycosaminoglycans (GAG) and to explore the putative role of prostaglandin E(2) (PGE(2)) in this process. Exposure of the cells for 24 h to IL-1beta induced a significant (P < 0.05) dose-dependent increase in GAG synthesis. IL-1beta (1 ng/ml) induced the expression of cyclooxygenase-2 (COX-2) protein 6 h after treatment, accompanied by a 7.5-fold increase in PGE(2) production. We confirmed that NS398, a selective COX-2 inhibitor, dose-dependently blocked PGE(2) augmentation following IL-1beta treatment. AH23848, the selective EP(4) receptor antagonist, completely abolished IL-1beta-induced GAG synthesis, whereas AH6809, an EP(2) receptor antagonist, had no effect on the stimulatory effects of IL-1beta. Furthermore, we demonstrated that 6 h exposure to IL-1beta induced a notable increase in EP(4) receptor mRNA expression and a decrease in EP(1) receptor mRNA but had no effect on the expression of EP(2) and EP(3) receptor transcripts. In conclusion, these findings indicate that IL-1beta not only induced GAG synthesis by increasing COX-2 protein expression and the subsequent PGE(2) production but also enhanced the responsiveness of cervical fibroblasts to PGE(2) by selectively up-regulating EP(4) receptor mRNA expression. These results suggest that PGE(2) may regulate human cervical ripening in an autocrine/paracrine manner via EP(4) receptors.

Cytotoxicity and apoptotic inducibility of Vitex agnus-castus fruit extract in cultured human normal and cancer cells and effect on growth.

A crude extract was prepared with ethanol from dried ripened Vitex agnus-castus fruits growing in Israel (Vitex extract). Cytotoxicity of the extract against human uterine cervical canal fibroblast (HCF), human embryo fibroblast (HE-21), ovarian cancer (MCF-7), cervical carcinoma (SKG-3a), breast carcinoma (SKOV-3), gastric signet ring carcinoma (KATO-III), colon carcinoma (COLO 201), and small cell lung carcinoma (Lu-134-A-H) cells was examined. After culture for 24 h (logarithmic growth phase) or 72 h (stationary growth phase), the cells were treated with various concentrations of Vitex extract. In both growth phases, higher growth activity of cells and more cytotoxic activity of Vitex extract were seen. The cytotoxic activity against stationary growth-phase cells was less than that against logarithmic growth-phase cells. DNA fragmentation of Vitex extract-treated cells was seen in SKOV-3, KATO-III, COLO 201, and Lu-134-A-H cells. The DNA fragmentation in Vitex extract-treated KATO-III cells was inhibited by the presence of the antioxidative reagent pyrrolidine dithiocarbamate or N-acetyl-L-cysteine (NAC). Western blotting analysis showed that in Vitex extract-treated KATO-III cells, the presence of NAC also inhibited the expression of heme oxygenase-1 and the active forms of caspases-3, -8 and -9. It is concluded that the cytotoxic activity of Vitex extract may be attributed to the effect on cell growth, that cell death occurs through apoptosis, and that this apoptotic cell death may be attributed to increased intracellular oxidation by Vitex extract treatment.

Increased Expression of Matrix Metalloproteinases in the Uterine Cervix of Postmenopausal Women

OBJECTIVE.: To determine whether atrophy of the uterine cervix in menopausal women is associated with an increased expression of matrix metalloproteinases (MMP), a decrease in their counter regulatory proteins (tissue inhibitors of matrix metalloproteinase [TIMP]), and a decrease in type I collagen. MATERIALS AND METHODS.: A pilot study was performed on cervical stroma harvested from 10 premenopausal and 9 postmenopausal women undergoing a hysterectomy. The amount of pro-MMP-2 and pro-MMP-9 in protein extracts from the two groups was compared by gelatin zymography. The membrane-type (MT)1-MMP, TIMP-1, and TIMP-2 were quantitated by Western immunoblotting. Total collagen was estimated by measuring hydroxyproline content. A primary fibroblast culture was developed to study estrogen regulation of MMP expression in vitro. RESULTS.: Pro-MMP-2 and pro-MMP-9 were increased in postmenopausal extracts. No difference in the amount of MT1-MMP, TIMP-1, TIMP-2, or total collagen was detected. In primary cervical fibroblast cultures, only active MMP-2 was suppressed by estrogen. CONCLUSIONS.: The protein expression of pro-MMP-2 and pro-MMP-9 is increased in cervical stroma of postmenopausal women relative to premenopausal women.

Increased level of matrix metalloproteinases 2 and 9 in the ripening process of the human cervix.

The human uterine cervix is a fibrous organ with a high connective tissue content. An extensive remodeling of the connective tissue prior to parturition, i.e., cervical ripening, requires the presence of proteolytic enzymes. The exact mechanism of cervical ripening has not been clarified. We evaluated in vivo distribution and expression of matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) in the human cervix at term pregnancy and immediately after parturition compared with the nonpregnant state. Cervical biopsies were obtained from term pregnant, postpartum, and nonpregnant women. MMP-2 and MMP-9 proteins were localized by immunohistochemistry. Messenger RNA levels of MMP-2 and MMP-9 were evaluated by relative quantitative reverse transcription-polymerase chain reaction (RT-PCR) using an invariable internal standard. The mRNA levels of MMP-2 and MMP-9 were increased in the cervix at term pregnancy and postpartum compared with the nonpregnant state. Cervical stromal fibroblasts and smooth muscle cells were identified as main sources of MMP-2, whereas the MMP-9 protein was observed exclusively in invading leukocytes. These data indicate the involvement of MMP-2 and MMP-9 in the cervical ripening process.

Prostaglandin F(2alpha), cytokines and cyclic mechanical stretch augment matrix metalloproteinase-1 secretion from cultured human uterine cervical fibroblast cells.

Human uterine cervical tissue is composed mainly of fibroblast cells and the extracellular matrix in which collagen types I and III predominate. It is hypothesized that these collagens are degraded by matrix metalloproteinases (MMPs) in the initial step of uterine cervical ripening during parturition. Among the MMPs, MMP-1, -8 and -13 have substrate selectivity for collagen types I and III. In the present study, we examined the regulation of MMP-1 secretion from the human uterine cervix. Immunohistochemistry detected strong staining of MMP-1, but not of MMP-8 or -13, in stromal cells of the pregnant uterine cervix. The MMP-1 expression in the pregnant uterine cervix was further confirmed by Western blot analysis and RT-PCR. To clarify the regulation of MMP-1 production, we subsequently investigated the effects of prostaglandins, inflammatory cytokines and cyclic mechanical stretch on the secretion of MMP-1 from cultured human uterine cervical fibroblast cells. Treatment with prostaglandin (PG)F(2alpha) (10(-7) to 10(-5) mol/l) or interleukin (IL)-1alpha (0.01-1.0 ng/ml) or stimulation with cyclic mechanical stretch increased MMP-1 secretion from cultured human uterine cervical fibroblast cells, with maximal increases of 3.4-, 4.5- and 1.9-fold respectively (24 h of treatment, P < 0.05 for all comparisons). These data suggest that MMP-1 may play a significant role in the degradation of extracellular collagen types I and III in the pregnant uterine cervix during the process of cervical ripening, in response to various stimulations such as PGF(2alpha), IL-1alpha and mechanical stretch.

Camelliin B induced apoptosis in HeLa cell line

Gordonia axillaris (Roxb.) Dietrich (Theaceae) is a native to Taiwan and the leaves have been used as an astringent folk medicine. Camelliin B (CB), a macrocyclic hydrolyzable tannin, was isolated from G. axillaris and showed cytotoxic effects in human carcinoma cells. Among the target cells (SKHep-1, Ha-22T, DU-145, AGS, and HeLa), the cervical carcinoma cell line, HeLa, was more sensitive to CB than were Chang normal liver cells and primary-cultured normal gingival and cervical fibroblasts. Furthermore, the cytotoxic effects of CB showed dose-dependency at 3.2–100.0 μg/ml in HeLa for 1, 24, 48, and 72 h and with an IC 50 value of 46.3 μg/ml for 48 h. However, the IC 50 value of CB in primary-cultured normal cervical fibroblasts was 108.0 μg/ml. Therefore, the selectivity shown by CB was ascribed to the difference in growth speed between normal and tumor cells. HeLa cells and primary-cultured normal cervical fibroblasts were treated with 50.0 and 100.0 μg/ml CB for 48 h, respectively, and exhibited chromatin condensation, indicating the occurrence of apoptosis. Flow cytometric analysis demonstrated the presence of apoptotic cells with low DNA content, a decrease of cell population at the G 1 phase, and a concomitant increase of cell population at the G 2/M phase. CB also caused DNA fragmentation and inhibited PARP degradation in HeLa cells. However, CB did not significantly inhibit Bcl-2 expression in HeLa cells at 50.0 μg/ml, only at 100.0 μg/ml for 48 h. These results suggest that CB induced apoptosis, without direct inhibition of Bcl-2 expression in HeLa cells.

Nitric oxide increases matrix metalloproteinase-1 production in human uterine cervical fibroblast cells.

Since uterine cervical ripening is an active biochemical process similar in part to an inflammatory reaction, nitric oxide (NO) has been proposed as a key mediator of this event. However, the mechanism by which NO modulates human cervical ripening has not been fully elucidated. In the present study we investigated the presence of NO synthases in human uterine cervix by immunohistochemistry and reverse transcriptase-polymerase chain reaction analysis. Furthermore, we examined the presence of NO-mediated regulation of matrix metalloproteinase-1 (MMP-1) production in cultured human uterine cervical fibroblast cells using enzyme-linked immunosorbent assay and Northern blot analysis. Endothelial and inducible NO synthases were detected in the form of mRNA and protein expression in pregnant uterine cervix. Interleukin-1alpha (IL-1alpha) increased the expression of inducible NO synthase mRNA in cultured human uterine cervical fibroblast cells. IL-1alpha also increased MMP-1 secretion from the cultured cervical fibroblast cells. This IL-1alpha-augmented MMP-1 secretion was partially but significantly blocked by an NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester. On the other hand, NO donors increased MMP-1 production in the cultured cervical fibroblast cells. These findings together suggest that NO contributes to the process of cervical ripening via enhancement of MMP-1 production, and that IL-1alpha increases MMP-1 secretion from cervical fibroblasts at least in part via NO synthesis.

Effects of platelet-activating factor on cytokine production by human uterine cervical fibroblasts.

Platelet-activating factor (PAF), a lipid that acts as a potent proinflammatory mediator, is involved in several reproductive processes including parturition. To investigate the effects of PAF on expression of various cytokines by cultured human uterine cervical fibroblasts obtained at term prior to labour, Northern blot analyses and enzyme-linked immunosorbent assays were performed. C-PAF, a stable analogue of PAF, increased expression of interleukin-6 and -8 mRNA in a dose-dependent manner (10(-10) to 10(-8) mol/l of C-PAF), and the expression peaked within 4 h. The corresponding protein concentrations were increased in culture media. Monocyte chemoattractant protein-1 mRNA showed marked induction by 10(-8) mol/l of C-PAF; this peaked by 4 h and was followed by an increase in the protein concentration. Another cytokine, RANTES (regulated upon activation, normal T cell expressed and secreted) showed marked mRNA induction by 10(-8) mol/l of C-PAF, and continued to increase in a time-dependent manner until 24 h. The protein concentration was correspondingly increased in the medium. The PAF-induced cytokine production was abolished by co-incubation with WEB 2170, a specific PAF receptor antagonist. PAF may stimulate local production of cytokines which may induce migration of leukocytes and accelerate collagenolysis in the uterine cervix, thus contributing to cervical ripening during parturition.

Hormonal regulation of PGE2 and COX-2 production in rabbit uterine cervical fibroblasts.

Prostaglandins (PGs) cause uterine contraction to initiate labor at term. We investigated the effect of progesterone and 17beta-estradiol on the production of PGE2 in rabbit uterine cervical fibroblasts. When the cervical fibroblasts were treated with interleukin-1alpha (IL-1alpha), the level of PGE2 was augmented in a time- and dose-dependent manner. The IL-1alpha-augmented PGE2 level was almost completely suppressed by progesterone and 17beta-estradiol at the physiological concentration (0.01 microM), whereas a slight decrease in the basal level of PGE2 was observed in the cervical fibroblasts treated with both hormones at a pharmacological concentration (1 microM). In addition, the level of PGE2 augmented by IL-1alpha was due to the increase of cyclooxygenase (COX) activity, which was inhibited by progesterone and 17beta-estradiol as well as by indomethacin and a specific COX-2 inhibitor, NS-398, but not by the well-known COX-1 inhibitor, aspirin. Furthermore, progesterone and 17beta-estradiol suppressed the IL-1alpha-augmented COX-2 production but not the constitutive production of COX-1 in rabbit uterine cervical fibroblasts. These results suggest that progesterone and 17beta-estradiol prevent the initiation of labor by inhibiting PGE2 production after the suppression of COX-2 production during pregnancy in the rabbit.

EP(4) receptors mediate prostaglandin E(2)-stimulated glycosaminoglycan synthesis in human cervical fibroblasts in culture.

The aim of this study was to determine the prostaglandin E (EP) receptors and second messengers implicated in glycosaminoglycan (GAG) synthesis by human cervical fibroblasts in culture. Human cervical fibroblasts were obtained from cervical biopsies in pre-menopausal, cycling women. Cultured cells were incubated with prostaglandin E(2) (PGE(2)) and an array of agonists and antagonists. Glycosaminoglycan synthesis was assayed after extraction by measuring the [(3)H]glucosamine and [(35)S]sulphate incorporated into GAG and cAMP production was determined by radioimmunoassay. PGE(2) significantly stimulated GAG synthesis. Neither 17-phenyl-trinor-PGE(2), the EP(1) selective agonist, nor sulprostone, an EP(3) agonist, had any effect on GAG production. Butaprost, the EP(2) selective agonist, also failed to increase GAG synthesis. AH6809, an EP(2) antagonist, had no effect on PGE(2)-stimulated GAG production. AH23848, an EP(4) antagonist, inhibited the GAG synthesis provoked by PGE(2). PGE(2) and butaprost significantly increased cAMP production. Both AH6809 and AH23848 inhibited the PGE(2)-stimulated cAMP production. H89, a cAMP-dependent protein kinase (PKA) inhibitor, did not inhibit PGE(2)-stimulated GAG synthesis and Sp-cAMPS, a selective PKA activator, failed to increase GAG production. In conclusion, both EP(4) and EP(2) receptors are present and functional in human cervical fibroblasts. Only EP(4) receptors mediate PGE(2) stimulated GAG synthesis in a PKA-independent pathway.

Hypoxia-stimulated expression of angiogenic growth factors in cervical cancer cells and cervical cancer-derived fibroblasts.

It is generally accepted that local growth of solid tumors and their ability to establish distant metastases are dependent on the formation of new blood vessels arising from preexisting ones (angiogenesis). The angiogenic response of the host is mediated by angiogenic molecules that are released from cancer and normal stroma cells, especially fibroblasts. The goal of the present study was to quantitatively compare the expression of the two most important angiogenic growth factors (VEGF, angiogenin) of cervical cancer cells (HeLa and Me-180) with that of cervical cancer-derived fibroblasts (from one tumor/patient) under defined normoxic and hypoxic conditions in vitro. The growth kinetics of cervical cancer cells (HeLa and Me-180) and tumor-derived fibroblasts were evaluated in vitro under normoxic and hypoxic conditions. Growth factor concentrations in the cell culture medium were measured by ELISA and the secretion rates per cell were calculated. Under normoxic conditions, both the cervical cancer cells as well as the tumor-derived fibroblasts released VEGF and angiogenin. The secretion rate of both angiogenic factors was significantly higher in the stroma cells than in the tumor cells (P < 0.05). VEGF and angiogenin secretion is significantly higher in the stroma cells under hypoxia than in the tumor cells investigated (P < 0.05). The presented data support the concept that in cervical cancer non-neoplastic fibroblasts could play a pivotal role in the complex process of tumor angiogenesis.

Hypoxia-stimulated expression of angiogenic growth factors in cervical cancer cells and cervical cancer-derived fibroblasts

Abstract. Pilch H, Schlenger K, Steiner E, Brockerhoff P, Knapstein P, Vaupel P. Hypoxia-stimulated expression of angiogenic growth factors in cervical cancer cells and cervical cancer-derived fibroblasts. It is generally accepted that local growth of solid tumors and their ability to establish distant metastases are dependent on the formation of new blood vessels arising from preexisting ones (angiogenesis). The angiogenic response of the host is mediated by angiogenic molecules that are released from cancer and normal stroma cells, especially fibroblasts. The goal of the present study was to quantitatively compare the expression of the two most important angiogenic growth factors (VEGF, angiogenin) of cervical cancer cells (HeLa and Me-180) with that of cervical cancer-derived fibroblasts (from one tumor/patient) under defined normoxic and hypoxic conditions in vitro. The growth kinetics of cervical cancer cells (HeLa and Me-180) and tumor-derived fibroblasts were evaluated in vitro under normoxic and hypoxic conditions. Growth factor concentrations in the cell culture medium were measured by ELISA and the secretion rates per cell were calculated. Under normoxic conditions, both the cervical cancer cells as well as the tumor-derived fibroblasts released VEGF and angiogenin. The secretion rate of both angiogenic factors was significantly higher in the stroma cells than in the tumor cells (P < 0.05). VEGF and angiogenin secretion is significantly higher in the stroma cells under hypoxia than in the tumor cells investigated (P < 0.05). The presented data support the concept that in cervical cancer non-neoplastic fibroblasts could play a pivotal role in the complex process of tumor angiogenesis.

Hypoxia-stimulated expression of angiogenic growth factors in cervical cancer cells and cervical cancer-derived fibroblasts

It is generally accepted that local growth of solid tumors and their ability to establish distant metastases are dependent on the formation of new blood vessels arising from preexisting ones (angiogenesis). The angiogenic response of the host is mediated by angiogenic molecules that are released from cancer and normal stroma cells, especially fibroblasts. The goal of the present study was to quantitatively compare the expression of the two most important angiogenic growth factors (VEGF, angiogenin) of cervical cancer cells (HeLa and Me-180) with that of cervical cancer-derived fibroblasts (from one tumor/patient) under defined normoxic and hypoxic conditionsin vitro.The growth kinetics of cervical cancer cells (HeLa and Me-180) and tumor-derived fibroblasts were evaluatedin vitrounder normoxic and hypoxic conditions. Growth factor concentrations in the cell culture medium were measured by ELISA and the secretion rates per cell were calculated. Under normoxic conditions, both the cervical cancer cells as well as the tumor-derived fibroblasts released VEGF and angiogenin. The secretion rate of both angiogenic factors was significantly higher in the stroma cells than in the tumor cells (P&lt; 0.05). VEGF and angiogenin secretion is significantly higher in the stroma cells under hypoxia than in the tumor cells investigated (P&lt; 0.05). The presented data support the concept that in cervical cancer non-neoplastic fibroblasts could play a pivotal role in the complex process of tumor angiogenesis.

Improvement of Separation Method of Fragmented DNA from an Apoptotic Cell DNA Sample for the Quantitation Using Agarose Gel Electrophoresis.

In order to quantify fragmented DNA extracted from apoptotic cells, we devised a separation method which condenses fragmented DNA into a small band, separating it from larger-size DNA with agarose gel electrophoresis. Calf thymus DNA and standard fragmented DNA were loaded onto 1.0% gel for 0.5, 1.0, 1.5 and 2.0 cm length, and onto 0.7, 1.0, 1.5 and 2.0% of gels for 1 cm length. DNA was then extracted from gel slices with the UltraClean 15 DNA Purification Kit, and estimated by measuring fluorescence intensity using Hoechst No.33258 dye. DNA recovery from the gel showed constant values regardless of the amount of loaded DNA up to 1 microg/assay, and a plot of loaded DNA amounts vs. the DNA amount yielded resulted in a strait line in any gel concentration used. Our results show the best conditions to estimate DNA fragmentation rates in apoptotic cells in which fragmented DNA was separated from thymus DNA by loading on 1.0% gel for 1.0 cm length. We used our method to estimate fragmentation rates in DNA fractions extracted from apoptotic human cervical fibroblast, amnion epithelial and chorion laeve trophoblast cells by stimulation with actinomycin D. The results show that DNA fragmentation rates in these cells were consistent with the electrophoretic patterns of the DNA samples shown by their photographs.

Effects of progesterone on prostaglandin E(2)-induced changes in glycosaminoglycan synthesis by human cervical fibroblasts in culture.

Prostaglandins are known to induce cervical ripening and this effect may be mediated by an increase in glycosaminoglycan (GAG) concentration. The aim of this study was to assess the effects of progesterone on prostaglandin E(2) (PGE(2))-induced changes in GAG synthesis by human cervical cells in culture. Human cervical fibroblasts were obtained by cervical biopsies in hormonally active women and cultured. Cells were submitted to an incubation with progesterone or control medium. A second incubation was then performed with increasing concentrations of PGE(2). GAG synthesis by the cervical cells was assayed after extraction, by incorporation of [(3)H]-glucosamine and [(35)S]-sulphate into GAGs. It was found that progesterone alone induced a dose-dependent increase in GAG synthesis. After pre-incubation with progesterone, PGE(2) further increased [(3)H]-glucosamine and [(35)S]-sulphate uptake. However, when expressed as percentage of stimulation, the stimulatory effect of PGE(2) on GAG synthesis was inhibited at high progesterone concentrations. Therefore we concluded that, although high concentrations of progesterone increase the overall synthesis of GAG, they may also play a preventative role against PGE(2)-induced changes in GAG production during pregnancy.

Platelet-Activating Factor Induces an Imbalance Between MatrixMetalloproteinase-1 and Tissue Inhibitor of Metalloproteinases-1 Expressionin Human Uterine Cervical Fibroblasts

Platelet-activating factor (PAF) is involved in such reproductive processes as parturition. We investigated the effect of PAF on the expression of matrix metalloproteinase-1 (MMP-1) and that of tissue inhibitor of metalloproteinases-1 (TIMP-1) in human uterine cervical fibroblasts. Uterine cervical tissue was obtained from patients who underwent cesarean section at term. Collagenase-dispersed fibroblasts were cultured and used in the experiments. PAF receptor was identified in the uterine cervical fibroblasts by use of reverse transcription-polymerase chain reaction and Southern blot analysis. Northern blot analysis showed that PAF increased the expression of MMP-1 mRNA in a time-dependent manner, whereas expression of TIMP-1 mRNA was not affected by PAF. Concentration of MMP-1 protein in the PAF-treated culture media significantly exceeded that in control cultures. The PAF-induced production of MMP-1 protein was abolished by treatment with WEB 2170, a specific PAF receptor antagonist. Results suggest that PAF may accelerate collagenolysis in the human uterine cervix by inducing an imbalance in the activity between MMP-1 and TIMP-1, thus contributing to the cervical ripening during parturition.