Cyclic nucleotide phosphodiesterase 4 subtypes are differentially expressed by primary keratinocytes and human epidermoid cell lines

The monoclonal antibody 5B5 reacts with the beta subunit of proline-4-hydroxylase, the enzyme which catalyses the formation of 4-hydroxyl proline in collagen and other proteins with collagen-like amino acid sequences. This study aims to assess the production and tissue distribution of this enzyme in normal and diseased synovia from patients with various joint diseases, on the basis that it is a putative marker of collagen-producing cells and, therefore, in this context, of fibroblasts. Sections from five normal, 10 osteoarthritic (OA) and 26 rheumatoid arthritic (RA) synovia were labelled with a mouse monoclonal antibody to proline-4-hydroxylase. The enzyme was found to be expressed by a proportion of synovial intimal cells and by fibroblasts in the underlying connective tissue in normal, OA and RA synovia. Labelling was more pronounced in OA and RA cases. The intimal cells labelling positively showed type B synoviocyte morphology, which was confirmed by subsequent double immunolabelling with 5B5 and antibody against type IV collagen using immunocytochemistry and immunoelectron microscopy.     

Distinct P-cadherin expression in cultured normal human keratinocytes and squamous cell carcinoma cell lines

A thermal threshold measurer (TTM) apparatus was developed and tested in 12 dry, nonpregnant, culled cows with the purpose of measuring the thermal nociceptive threshold and of finding the response to morphine sulphate dosages. The cows received a cumulative dose (from 0.00 to 0.40 mg/kg BW) of morphine sulphate through a catheter in the jugular vein. The interval between doses was 20 min, and a nociceptive test was performed 15 min after each injection. The TTM device consisted of a 60 W halogen bulb mounted in a 15 cm PVC tube, with a 0.6 s response time probe attached to its end, connected to a thermocouple. The probe measured the response temperature on the skin over the middle phalanges on the dorsum of the forefoot. The radiating heat stimulus from the bulb was instantaneously terminated with the foot-lift response of the tested animal. The nociceptive response to the 0.00 mg/kg dose was considered the baseline and subsequent measurements were expressed in difference from it. Data were evaluated in a regression analysis using the GLM procedure. A significant elevation (P < 0.0001) in the nociceptive threshold of the cows with cumulative dosing of morphine sulphate was noticed. A high variability (P < 0.0001) in the response among animals was also detected, suggesting that a 2-step dose of morphine sulphate is necessary to achieve a certain degree of induced analgesia in all cows. The nociceptive assay described, using the TTM device, was able to detect an elevation of the thermal threshold of cows due to morphine sulphate induced analgesia. An increase in locomotory behaviour or other side effects due to morphine sulphate were not noticed.     

Dose-dependent induction of IL-12 but not IL-10 from human keratinocytes after exposure to ultraviolet light A

OBJECTIVE: Our purpose was to assess the risk of ectopic pregnancy among women who smoke cigarettes. STUDY DESIGN: We used data from a case-control study of ectopic pregnancy conducted from October 1988 to August 1990 at an inner-city hospital in Georgia. Cases were 196 non-Hispanic black women with a surgically confirmed ectopic pregnancy. Controls were non-Hispanic black women who had delivered either a live or a stillborn infant weighing at least 500 gm (n = 882) or who were pregnant and seeking an induced abortion (n = 237). RESULTS: After we adjusted for parity, douching history, history of infertility, and age, the odds ratio for ectopic pregnancy was 1.9 (95% confidence interval 1.4 to 2.7) for women who smoked during the periconception period compared with women who did not smoke at that time. After stratification by the amount of daily smoking during the periconception period, the odds ratio rose from 1.6 (95% confidence interval 0.9 to 2.9) for women who smoked 1 to 5 cigarettes to 1.7 (95% confidence interval 1.1 to 2.8) for women who smoked 6 to 10 cigarettes to 2.3 (95% confidence interval 1.3 to 4.0) for women who smoked 11 to 20 cigarettes, and to 3.5 (95% confidence interval 1.4 to 8.6) for women who smoked >20 cigarettes per day. CONCLUSION: In this inner-city population, cigarette smoking was an independent, dose-related risk factor for ectopic pregnancy among black women. The public health and medical care communities should inform the public of this additional risk associated with cigarette smoking and intensify intervention strategies to reduce cigarette smoking among women of reproductive age.     

Cytokine (IL-10, IL-6) induction of tissue inhibitor of metalloproteinase 1 in primary human prostate tumor cell lines

Northern blots and scintillation counting showed that tissue inhibitor of metalloproteinase 1 (TIMP-1) mRNA was expressed by low passage, primary epithelial cultures (n = 5) of low-grade human prostatic carcinoma. TIMP-1 mRNA levels were normally low in the primary cell lines, but were inducible by interleukin (IL) 10 and 6. Dose and time-course studies indicated that IL-10 was the most potent stimulator of TIMP-1 expression. Cycloheximide blocked the effects of IL-10 in a reversible manner. In situ hybridization assays with TIMP-1 oligonucleotide antisense probes confirmed the northern blot results and indicated that IL-10 preferentially stimulated TIMP-1 mRNA synthesis. We suggest that IL-10, and to a lesser extent IL-6, may normally influence TIMP-1 expression by human prostatic epithelial cells.     

Gene mutations and increased levels of p53 protein in human squamous cell carcinomas and their cell lines

Using immunocytochemical and Western blotting techniques we have demonstrated the presence of abnormally high levels of p53 protein in 8/24 (33%) of human squamous cell carcinomas (SCC) and 9/18 (50%) of SCC cell lines. There was a correlation between the immunocytochemical results obtained with eight SCC samples and their corresponding cell lines. Direct sequencing of PCR-amplified, reverse transcribed, p53 mRNA confirmed the expression of point mutations in six of the positive cell lines and detected in-frame deletions in two others. We also detected two stop mutations and three out-of-frame deletions in five lines which did not express elevated levels of p53 protein. Several of the mutations found in SCC of the tongue (3/7) were in a region (codons 144-166) previously identified as being a p53 mutational hot spot in non-small cell lung tumours (Mitsudomi et al., 1992). In 11/13 cases only the mutant alleles were expressed suggesting loss or reduced expression of the wild type alleles in these cases. Six of the mutations were also detected in the SCCs from which the lines were derived, strongly suggesting that the mutations occurred, and were selected, in vivo. The 12th mutation GTG-->GGG (valine-->glycine) at codon 216 was expressed in line SCC-12 clone B along with an apparently normal p53 allele and is to our knowledge a novel mutation. Line BICR-19 also expressed a normal p53 allele in addition to one where exon 10 was deleted. Additionally 15 of the SCC lines (including all of those which did not show elevated p53 protein levels) were screened for the presence of human papillomavirus types 16 and 18 and were found to be negative. These results are discussed in relation to the pathogenesis of SCC and the immortalisation of human keratinocytes in vitro.     

In situ detection of PCR-amplified metalloproteinase cDNAs, their inhibitors and human papillomavirus transcripts in cervical carcinoma cell lines

Current fluorescence-based adhesion assays that use a 96-well plate format rely on the assumption that the fluorescent label does not significantly leak from the cells. Thus, we evaluated a calcein-based, in vitro adhesion assay in 96-well plates using five different types of leukocytes (HL60 cells, human neutrophils, rat neutrophils, mouse progenitor T cells and EL4 cells). Each cell type leaked calcein at a different rate, with the highest rates found for rat neutrophils and progenitor T cells, which lost as much as 20%-40% of the label within 90 min, the time required to complete the assay. Thus, we developed a procedure to measure the dye leakage rate during the assay in order to obtain a correction factor, which was then used to calculate the "true" number of adherent cells. Data for the adhesion of FTF1 cells to endothelial monolayers, after correction for calcein leakage, deviated less than 10% of adhesion data obtained with a well-established 51Cr-based assay.     

Interleukin-10 production by human carcinoma cell lines and its relationship to interleukin-6 expression

Recent data indicate a major role for IL-10 in suppressing immune and inflammatory reactions. To date, expression of human IL-10 has been attributed primarily to helper T lymphocytes, activated monocytes, and neoplastic B cells, and was often found to be associated with IL-6 expression. In this study we sought to determine whether non-hematopoietic human tumor cell lines produce IL-10 and, if so, what is the relationship between IL-10 and IL-6. Using ELISA, we determined IL-10 and IL-6 levels in culture supernatants of 48 cell lines established from carcinomas of the kidney, colon, breast and pancreas, malignant melanomas and neuroblastomas. IL-6 protein was secreted by 28 of the tumor cell lines; IL-10 was measurable in 15 cell lines. IL-6 secretion was maximal and most frequent in renal-cancer cell lines, while IL-10 production was found to be highest and most common among cell lines derived from colon carcinomas. IL-10 in conditioned medium of one of the colon carcinoma cell lines (CCL222) was bio-active, as demonstrated in the mouse MC/9 mast-cell-line assay and in human mixed-lymphocyte reactions. In both assays, IL-10 bio-activity was neutralized by an anti-IL-10 monoclonal antibody. Expression of IL-6 and IL-10 was confirmed by RNA analysis using message amplification by PCR and sequencing of amplified cDNA. LPS, IL-1 alpha, and TNF-alpha strongly enhanced the release of IL-6 by RCC cells, but only marginally affected IL-10 production in colon-carcinoma cells. IL-10 secretion by colon-carcinoma cells was moderately stimulated by IFN-gamma and IL-4. Dexamethasone suppressed the release of IL-6, but had no inhibitory effect on IL-10 secretion. Our results demonstrate that tumor cell lines established from certain types of human carcinomas are capable of expressing and releasing IL-6 and/or IL-10, suggesting a role of these cytokines in solid-tumor development and anti-tumor immunity.     

Differential sensitivity of human myeloma cell lines and normal bone marrow colony forming cells to a recombinant diphtheria toxin-interleukin 6 fusion protein

The cytotoxicity of a recombinant interleukin 6 (IL-6)-diphtheria toxin (DT) fusion protein towards human myeloma cell lines was investigated. DAB389-IL-6 inhibited protein synthesis and methylcellulose colony formation by U266 myeloma cells. In the clonogenic assay, the fusion protein approached the level of cytotoxicity achieved by native DT. The specificity of killing by DAB389-IL-6 was demonstrated by inhibition of cytotoxicity by a molar excess of free rhIL-6. The effect of DAB389-IL-6 on colony formation by six OCI-My cell lines was assessed. Similar to U266 cells, colony growth by the OCI-My 5 and -My 2 cell lines was inhibited in a simple dose dependent manner. However, a biphasic effect was observed for the IL-6 dependent OCI-My 4 cells; DAB389-IL-6 stimulated colony formation at low (< or = 10(-11) M) concentrations, yet was inhibitory at higher doses. Three other cell lines whose growth was not altered by IL-6 were relatively unaffected by DAB389-IL-6, despite their sensitivity to native DT. Flow cytometric analysis for IL-6 receptor expression using phycoerythrin-conjugated IL-6 demonstrated specific binding sites on both DAB389-IL-6 sensitive and certain insensitive cell lines, suggesting that other factors in addition to the expression of IL-6 receptors are involved in killing by the fusion toxin. Despite evidence for a role of IL-6 in myeloid cell development, normal bone marrow was insensitive to the IL-6 fusion toxin. In cultures containing both normal bone marrow and U266 cells DAB389-IL-6 effectively inhibited the growth of U266 myeloma colonies but had little effect on normal bone marrow erythroid, granulocyte and mixed erythroid/granulocyte colony growth. From these experiments we conclude that DAB389-IL-6 is specifically cytotoxic towards a subset of IL-6-responsive human myeloma cell lines and may be useful, in some cases, in the selective elimination of tumour cells from mixed populations of normal and malignant cells.     

A novel, complement factor H-related regulatory protein expressed on the surface of human B cell lines

Complement regulatory proteins present on the surface of various mammalian cells play an important role in controlling homologous lysis, by interacting with C3 (and usually C4). These proteins have a similar structural motif ("short consensus repeat") (Reid, K.B.M., Bentley, R.D., Campbell, R.D., Chung, L.P., Sim, R.B., Kristensen, T. and Tack, B.F., Immunol. Today 1986. 7:230), and the genes encoding them are members of the family of regulators of complement activation. Here we describe a hitherto unknown member of this family, a molecule expressed by B lymphoblastoid cells. This protein is recognized by polyclonal antibodies to factor H and by MAH4, a monoclonal antibody reacting with the N-terminal portion of factor H. The cell surface protein is built up of two disulfide-linked chains of approximately 68 and 75 kDa. Biosynthetic labeling studies confirmed that it is synthesized by B cells only, but not by the investigated lines of other origin. When tested for its functional activity, this molecule was shown to act as cofactor for factor I-mediated cleavage of fluid-phase C3b to C3bi. The protein appears to be encoded by a 3.5-kb mRNA, hybridizing with a cDNA probe coding for the N-terminal portion of factor H. Due to its cross-reactivity with anti-H antibodies, cofactor activity for factor I and hybridization with factor H cDNA, despite its two-chain composition, it is considered a factor H-like protein.     

Viral interleukin 10 (IL-10), the human herpes virus 4 cellular IL-10 homologue, induces local anergy to allogeneic and syngeneic tumors

After the cloning of murine cytokine synthesis inhibitory factor, it was recognized that a homologous open reading frame was encoded within the Epstein-Barr virus (human herpes virus 4). This viral protein has now been termed viral interleukin 10 (vIL-10) to reflect its protein sequence homology to "cellular" IL-10 (cIL-10, either murine or human IL-10). It is now widely accepted that vIL-10 shares many functions with cIL-10, principally, the ability to enhance survival of newly infected B cells and to diminish the production of IFN-gamma and IL-2 during ongoing immune reactions. The immunomodulatory effect of locally secreted vIL-10 and murine IL-10 (mIL-10) was examined in tumor models using CL8-1 (a BL6 melanoma cell line transfected with the H-2Kb class I gene) in syngeneic animals. Although parental BL6 tumor cells grow in immunocompetent syngeneic hosts, CL8-1 are rejected. To achieve local secretion of vIL-10, we generated vIL-10 retroviral vectors. While nontransduced CL8-1 cells (1 x 10(4)) failed to grow when injected intradermally in C57BL/6 mice, CL8-1 cells (1 x 10(4)) transduced with vIL-10 formed palpable tumors and eventually killed 80% of injected animals. Suppression of tumor rejection was also noted when CL8-1 tumors with or without vIL-10 transfection were admixed with syngeneic vIL-10-transfected fibroblasts and inoculated. Since the in vitro proliferation of the tumor was not altered after transduction with the vIL-10 gene and injection of vIL-10-transduced CL8-1 does not affect the rejection of nontransduced CL8-1 inoculated at a distant site, local vIL-10 secretion appears to suppress the process of immune rejection of the target cells in a dose-dependent manner. Similar results were observed for the H-2b MCA105 sarcoma tumor model in allogeneic BALB/c mice (H-2d). Although all animals that received nontransfected MCA105 rapidly rejected these tumors, MCA105 sarcomas transfected with vIL-10 remained palpable for up to 37 d. The local immunosuppressive effect of gene-delivered vIL-10 could be neutralized by anti-human IL-10 monoclonal antibody or could be reversed by the systemic administration of IL-2 or IL-12. In marked contrast, mIL-10 transfection of CL8-1 significantly suppressed tumor growth and frequently led to the rejection of tumor. Similar results were obtained for the murine tumor cell lines MCA102.(ABSTRACT TRUNCATED AT 400 WORDS)     

Recombinant human growth-regulated oncogene-alpha induces T lymphocyte chemotaxis. A process regulated via IL-8 receptors by IFN-gamma, TNF-alpha, IL-4, IL-10, and IL-13

The human cytokine growth-regulated oncogene (GRO)-alpha is a small glycoprotein secreted by monocytes, endothelial cells, glycoprotein secreted by monocytes, endothelial cells, fibroblasts, synovial cells, and some tumor cells such as melanoma cells. It is structurally related to IL-8 and can activate neutrophils, whereas it induces chemotaxis, exocytosis, and a respiratory burst in neutrophils. To date, its functions on T lymphocytes have not been well established. We report here that recombinant human (rh)GRO-alpha is a potent chemoattractant for freshly isolated T lymphocytes, but not for anti-CD3 mAb-activated T lymphocytes. It attracts CD4+ and CD8+ T lymphocyte subsets to an equal extent. The migrating T lymphocytes toward rhGRO-alpha are predominantly CD45RO+ memory CD4+ and CD8+ subsets. The chemotactic migration of T lymphocytes toward rhGRO-alpha is stimulated via the IL-8 receptors on the cells. This process can be augmented by IFN-gamma and TNF-alpha, and inhibited by IL-4, IL-10, and IL-13. In addition, we also document that on T lymphocytes there exist IL-8 receptors that can be up-regulated by IFN-gamma, TNF-alpha, and IL-2. Our results demonstrate that rhGRO-alpha gene encodes for an inflammatory mediator that stimulates the directional migration of T lymphocytes. It may thus be another important mediator in the diseases in which T lymphocytes form the major constituent of the cellular infiltration.     

Expression of topoisomerase II, bcl-2, and p53 in three human brain tumor cell lines and their possible relationship to intrinsic resistance to etoposide

We characterized three human brain tumor cell lines (D54, HBT-20, and HBT-28) with respect to resistance to etoposide (VP-16), a topoisomerase II-reactive drug. All three cell lines were inherently resistant to VP-16 when compared to other human cell lines, with D54 showing the greatest resistance using colony formation assays. Resistance to VP-16 has been attributed to decreased drug uptake and changes in topoisomerase II; however, drug uptake and topoisomerase II protein levels (immunoblot) were no lower in D54 than in HBT-20 and HBT-28, cell lines relatively more sensitive to VP-16. More to the point, measurement of topoisomerase II-mediated DNA cleavage of cellular DNA after treatment with VP-16 showed that the topoisomerase II in these cells was active. These data indicate mechanisms other than those attributable to decreased drug uptake or altered topoisomerase II exist for clinical resistance to VP-16. VP-16-induced DNA cleavage has been associated with apoptosis in some cell lines; however, neither DNA laddering nor morphological changes characteristic of apoptosis were detected in these cell lines after treatment with VP-16. Bcl-2 and mutant p53 were present in these cells. Either of these conditions can prevent apoptosis and could explain a dissociation between the proximal mediator of VP-16-induced cytotoxicity (topoisomerase II-DNA complex formation) and cellular death.     

Growth inhibitory response to activin A and B by human prostate tumour cell lines, LNCaP and DU145

Activins are growth and differentiation factors which have been shown to have proliferative and antiproliferative actions in many tissues. In addition, they have been implicated in tumourigenesis in reproductive tissues. Although activin and inhibin are present in rat ventral prostate, inhibin beta, but not alpha, subunit proteins have been detected in the human prostate epithelial tumour cell lines LNCaP, DU145 and PC3. With this absence of capacity to produce inhibins, the aims of this study were to determine the effect of activin A and B and follistatin on DNA synthesis by these human prostate tumour cell lines. The results demonstrate a differential response to exogenously added activin A and B on DNA synthesis in vitro by the tumour cell lines. The inhibitory effects were observed on LNCaP cells in the absence or presence of stimulation with 1 nM 5 alpha-dihydrotestosterone and on the androgen-independent DU145 cells, but not the PC3 cells. Activin A caused a dose-dependent inhibition of DNA synthesis and proliferation by LNCaP and androgen-independent DU145 cells which was maximal at 8 ng/ml. The effect of exogenously added activin A was completely reversed by follistatin, but not by inhibin A. The addition of human recombinant FS 288 alone (400 ng/ml) did not have any effect on DNA synthesis, whereas inhibin A alone (400 ng/ml) caused a significant inhibition of DNA synthesis. The capacity of all three cell lines to produce activins and follistatins was demonstrated by the expression of the mRNAs and confirmed by the localisation of immunoreactivity for these ligands to the cytoplasm of the tumour cells. The growth inhibitory response to activins A and B by LNCaP and DU145 cells, and the ability of follistatin to block these effects, suggest that the autocrine interactions between activins and follistatins have a role in the regulation of LNCaP and DU145 prostate tumour cell growth.     

The effect of dacarbazine and vincristine sulfate on human melanoma cell lines. In vitro analysis of interaction on DNA synthesis, RNA synthesis and protein synthesis

The effect of anticancer agents, dacarbazine [DTIC (dimethyl-triazeno-imidazole-carboxamide)] and vincristine sulfate (VCR) on two human melanoma cell lines (G 361 and MeWo) was investigated. First we estimated the growth curve of two cell lines by using an isotope labelling technique with DNA, RNA and protein precursors to find the most appropriate conditions, and then, DTIC and VCR were added at various concentrations. When the drug was added alone, DNA, RNA and protein synthesis were suppressed in a dose-dependent fashion and the pattern of responses was similar between the two. When the two agents were administered in combination, responses were variable depending on the combinations of the concentrations of these agents. It was also observed that the response on DNA synthesis is not similar to that on RNA or protein synthesis, and that unbalanced growth can happen when two anticancer agents, whose mechanisms of action against tumour cells, are different, are administered at the same time. These observations also differed between the two cell lines. It suggests that these diverse responses of melanoma cells against chemotherapeutic agents hinder the establishment of a sensitive combination chemotherapeutic regimen.     

In vitro effect of the cysteine metabolites homocysteic acid, homocysteine and cysteic acid upon human neuronal cell lines

Cysteine (CYS) is a non-essential amino acid which elicits excitotoxic properties via the N-methyl-D-aspartate (NMDA) subtype of the glutamate receptor. CYS levels are known to be elevated in association with neurological disease such as Alzheimers Disease (AD) and Parkinsons Disease (PD). We have previously reported studies investigating the toxicity of CYS and its major metabolite cysteinesulfinic acid (CSA) to human neuronal cell lines in vitro and in continuation of this we now report the toxicity of other compounds (Homocysteic Acid, HCA; Homocysteine, HCYS; and Cysteic Acid, CA) in the CYS metabolic pathway. Three cell lines, all of human origin and derived from separate discrete areas of the brain were used in the neurotoxicity assays. Lactate dehydrogenase (LDH) release was assayed as a measure of cell death. The cell lines investigated showed varying degrees of toxic responses which were the reverse of those seen when they were exposed to CYS or CSA. The SK.N.SH (Neuroblastoma) cell line, which exhibits a high toxic response to CYS and CSA, gave a low toxic response to HCA and CA while the TE 671 (Medulloblastoma) cell line, which exhibits a low toxic response to CYS and CSA, showed a high toxic response to HCYS, HCA and CA. However, the U-87 MG (Glioblastoma) cell line, which has a median toxic response to CYS and CSA, also has median response to HCYS, HCA and CA. These results show that toxic responses are cell-type specific for CYS and its metabolites and this may be reflected in the patterns of neurodegeneration observed in such diseases as AD and PD. HCYS is selectively toxic to medulloblastoma cells; this may explain why high HCYS levels result in neural tube defects in prenatal humans, where the same cell-type is involved.