A comparison of the antitumor effects of interferon-alpha and beta on human hepatocellular carcinoma cell lines

The antiviral, antiproliferative and immunomodulatory effects of type I interferons (IFNs) are well documented, however, few studies have been published concerning differences in the antitumor effects of IFN-alpha and beta. In the present study, differences in antitumor effect, including the antiproliferative effect, cell cycle change, apoptosis, and the IFN-stimulated gene (ISG) were examined by flow cytometry between IFN-alpha and beta on three human hepatocellular carcinoma (HCC) cell lines (HepG2, Huh7 and JHH4). The antiproliferative effect of both IFNs on the HCC cell lines was time- and dose-dependent, and IFN-beta was significantly stronger than IFN-alpha. The cell cycle effect by both IFNs was an S-phase accumulation, with IFN-beta having a tendency to increase the S-phase ratio more strongly than IFN-alpha, especially in Huh7. Apoptosis marker expression, Fas antigen and intracellular active caspase-3, was increased after the addition of IFNs, especially of IFN-beta. The expression of human leukocyte antigen-class I molecules, ISG-encoded protein, was increased after the addition of IFNs, especially of IFN-beta. These data suggest that IFN-beta has a greater antitumor effect than IFN-alpha on HCC of a very early stage in patients with chronic hepatitis C.     

The effect of cell synchronization upon the detection of T and B lymphoid cell receptors on two continuous lymphoid cell lines

Summary In the present study, the effect of the cell synchronization on the detection of T and B cell surface markers of two continuous lines of lymphoid cells (FL-74 and CT45-S) was examined. Suspension cultures were synchronized by deprivation of isoleucine and surface markers were quantitated by T rosette formation with guinea pig erythrocytes (E) and B rosette formation with an erythrocyte-antibody-complement (EAC) complex. After 24 hr, cells were resuspended in complete culture medium. Virtually 100% of FL-74 cells expressed the T cell marker at time 0, with a progressive decline to 80% at saturation density. A bell-shaped curve for expression of the EAC marker on CT45-S cells was seen with maximum expression in the logarithmic phase of the growth cycle. Spent culture medium was examined for the presence of free soluble receptor. Preincubation of E and EAC in appropriate old medium resulted in 42% inhibition of E rosettes and 42% inhibition of EAC rosettes with FL-74 and CT45-S cells, respectively. Thus quantitation of lymphocyte subpopulations as B, T or null cells with these cellular markers may be influenced by the age of the cell examined, phase of the cell cycle and the amount of free receptor present in the surrounding medium. This research was supported in part by contract NO1 CP 5-3571 with the Virus Cancer Program of the NCI, NIH, PHS grant no. 2 RO1 A1-09022-07, Allergy and Infectious Diseases NIH, PHS and The State of Ohio Canine Research Funds.     

Mitosis-arresting effects of cigarette smoke condensate on human lymphoid cell lines

Whole-smoke condensates from the University of Kentucky reference cigarettes induced partial mitotic arrest in 4 human lymphoid cell lines. Treatment of cells for 3 h with 100 and 200 μg of cigarette-smoke condensate/ml of culture medium increased the frequency of metaphases and decreased the proportion of anaphases in the treated cell populations. Cytoskeletal studies using antitubulin immunofluorescence techniques and transmission electron microscopic studies demonstrated that in early stages of mitosis the formation of aster and the separation of centrosomes in condensate-treated cells were comparable to those of untreated control cells, but the poleward migration of centrosomes was inhibited. Arrested metaphases revealed two centrosomes surrounded by aggregated chromosomes in the center of each cell but the structure of the centrioles, microtubules and the kinetochores appeared normal. The results demonstrate the presence of antimitotic compounds in the tobacco-smoke condensate.     

Synergistic antiproliferative effects of glucocorticoids and interferon-alpha on some lymphoid cell lines

The Daudi B lymphoblastoid cell line was previously demonstrated to be highly sensitive to the antiproliferative effect of recombinant interferon-alpha A (rIFN-alpha A). In the present study, glucocorticoid hormones were shown to act synergistically with rIFN-alpha A to further increase the sensitivity of Daudi cells to rIFN-alpha A. At 10(-6) M, dexamethasone, prednisolone, or hydrocortisone alone had little effect on Daudi cell growth, but they greatly potentiated the antiproliferative activity of rIFN-alpha A. The synergy between rIFN-alpha A and glucocorticoids on Daudi cells was not related to the inhibitory effects of glucocorticoids on prostaglandin or leukotriene synthesis, since no synergy was observed between rIFN-alpha A and indomethacin or nordihydroguaiaretic acid. Glucocorticoids and rIFN-alpha A also had appreciable synergistic antiproliferative effects on two out of five other IFN-sensitive lymphoid cell lines. When Raji B lymphoblastoid cells, which were quite resistant to the antiproliferative effect of rIFN-alpha A, were treated with the combination of glucocorticoids and rIFN-alpha A, no significant synergistic effects were observed. The synergistic antiproliferative effects of glucocorticoids and rIFN-alpha A observed with some IFN-sensitive lymphoid cell lines in this in vitro study may have clinical relevance in the treatment of certain lymphoid malignancies that are sensitive to rIFN-alpha A therapy.     

The effect of cell synchronization upon the detection of T and B lymphoid cell receptors on two continuous lymphoid cell lines.

In the present study, the effect of the cell synchronization on the detection of T and B cell surface markers of two continuous lines of lymphoid cells (FL-74 and CT45-S) was examined. Suspension cultures were synchronized by deprivation of isoleucine and surface markers were quantitated by T rosette formation with guinea pig erythrocytes (E) and B rosette formation with an erythrocyte-antibody-complement (EAC) complex. After 24 hr, cells were resuspended in complete culture medium. Virtually 100% of FL-74 cells expressed the T cell marker at time 0, with a progressive decline to 80% at saturation density. A bell-shaped curve for expression of the EAC marker on CT45-S cells was seen with maximum expression in the logarithmic phase of the growth cycle. Spent culture medium was examined for the presence of free soluble receptor. Preincubation of E and EAC in appropriate old medium resulted in 42% inhibition of E rosettes and 42% inhibition of EAC rosettes with FL-74 and CT45-S cells, respectively. Thus quantitation of lymphocyte subpopulations as B, T or null cells with these cellular markers may be influenced by the age of the cell examined, phase of the cell cycle and the amount of free receptor present in the surrounding medium.     

Opposing effects of 12-o-tetradecanoylphorbol 13-acetate on human myeloid and lymphoid cell proliferation

The effect of 12-O-tetradecanoylphorbol 13-acetate (TPA) on human hematopoietic cells has been investigated. It was found that 1–10 ng/ml of TPA totally abrogated erythroid and granulocytic colony growth and, simultaneously in the presence of PHA, stimulated T-lymphocyte colony formation. TPA concentrations insufficient to inhibit myeloid colony growth also failed to stimulate lymphocyte colony formation. Optimal culture conditions for the growth of these colonies required the presence of TPA, PHA, and leukocyte-conditioned medium in the cultures. Cells within the colonies were 80–90% E-rosette positive and by monoclonal antibody characterization contained 45–66% OKT3-positive cells. Colony-forming cells were found in both E-rosette-positive and-negative fractions. Although by cell surface marker characterization the cells within the colonies had properties of T-cells, the exact relationship of cells forming colonies under these conditions to those detected in other T-cell colony assays remain to be determined.     

Establishment of the AU-bek cell line and comparison with two other bovine cell lines

Summary Establishment of a new bovine cell line, AU-BEK, is reported. The cell line developed in a culture initiated from bovine embryonic kidneys by spontaneous cultural alteration to epithelioid cells that are indefinitely propagable. Epithelioid cells gradually increased to become the predominant cell. Whereas normal bovine cells have a diploid number of 60 chromosomes, of which only the two sex chromosomes are biarmed, AU-BEK cells at the 80th passage had a modal chromosome number of 84 and an average of 30 biarmed chromosomes per cell. AU-BEK cells are now in their 220th passage. Of the AU-BEK, MDBK, and CKT-1 bovine cell lines, the CKT-1 cell line had a karyotype closest to that of normal bovine cells. Their modal chromosome number was 57, and only three biarmed chromosomes were usually present. The bovine character of AU-BEK and CKT-1 cells was established by cytotoxic and viral susceptibility tests. Supported by the Alabama Agricultural Experiment Station. Publication No. 1115, School of Veterinary Medicine, Auburn University.     

Regulation of IL-6 receptor and gp130 expression on human cell lines of lymphoid and myeloid origin.

The expression of 80 kDa interleukin-6 receptor (IL-6R) and the associated molecule gp130 has been studied on human cell lines by FACS- and Northern blot analysis. The effects of dexamethasone, dibutyric-(DB)-cAMP and phorbol-12-myristate-13-acetate (TPA) have been studied on plasmacytoma cell line U266, B cell line BMNH and monocytoid cell line U937. Our data show a definite downregulation of IL-6R and gp130 expression by TPA in U266 and BMNH at both mRNA and cell surface protein levels. In U937 TPA inhibits only the IL-6R expression, without affecting that of gp130. DB-cAMP decreases the expression of both proteins in U937, slightly inhibits the IL-6R expression in U266, but is uneffective in BMNH. Dexamethasone induces considerable upregulation of gp130 only in U266. Our findings suggest separate regulation of IL-6R and gp130 on U266, BMNH and U937 cell lines.     

Combined effects of aspirin and vitamin D3 on two OSCC cell lines: a preliminary study

Objectives

We evaluated the potential effects of aspirin combined with vitamin D3 on cell proliferation and apoptosis in oral cancer cells.

Results

Compared to the untreated control or individual drug, the combinations of aspirin and vitamin D3 significantly decreased the rates of cell proliferation by CCK-8 assay, and caused higher rates of cell apoptosis in both CAL-27 and SCC-15 cells by Annexin V-FITC apoptosis assay and flow cytometry. Remarkably, the combined treatment with aspirin and vitamin D3 significantly suppressed the expression of Bcl-2 protein and p-Erk1/2 protein, examined by western blot analysis.

Conclusions

Our study demonstrates that aspirin and vitamin D3 have biological activity against two human OSCC cell lines and their activity is synergistic or additive when two drugs used in combination with therapeutic concentrations. The combination of aspirin and vitamin D3 may be an effective approach for inducing cell death in OSCC.

     

Characterization of corticosteroid receptors in natural killer cells: comparison with circulating lymphoid and myeloid cells

Lymphocytes mediating natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities are relatively refractory to the changes in circulatory traffic and intrinsic function induced in other cell types by in vivo and in vitro corticosteroids (CS). To investigate if such drug resistance could be attributed to differences in the CS receptor number of affinity (Kd) of these cells, these characteristics were determined in purified populations of large granular lymphocytes (LGL), monocytes, neutrophils (PMN), and T cells. All cell types displayed a single class of CS receptor of uniform affinity; however, LGL resembled monocytes and PMN in receptor number and Kd while T cells had significantly fewer sites per cell with lower Kd. These studies suggest that the unresponsiveness of NK activity to CS is not secondary to differences in CS receptor capacity or affinity.     

Interferon-gamma induces enhanced expression of Ia and H-2 antigens on B lymphoid, macrophage, and myeloid cell lines

The levels of class II major histocompatibility complex (MHC) antigens (la antigens) on cells of a cultured B lymphoma line (WEHI-279) were significantly increased after 24 hr incubation with medium conditioned by concanavalin A-stimulated mouse or rat spleen cells, or by an azobenzenearsonate- (ABA) specific T cell clone that had been stimulated with ABA-coupled spleen cells or concanavalin A. The levels and properties of the la-inducing activity correlated with those of interferon-gamma (IFN-gamma) measured by inhibition of virus plaque formation. Both the la-inducing activity and the IFN-gamma from the T cell clone had an apparent m.w. of 40,000 determined by gel filtration, were sensitive to treatment with trypsin or exposure to pH 2, but were stable to heat (56 degrees C, 1 hr). The induction of la antigens on WEHI-279 cells was dose-dependent, and the maximum response occurred at a concentration corresponding to 1 to 2 U/ml of antiviral activity. This T cell-derived IFN-gamma-like molecule also increased the expression of cell surface la antigens on another B cell line (WEHI-231), and cell lines of macrophage (J774) and myeloid (WEHI-3B and WEHI-265) origin. Furthermore, in all cases the levels of class I MHC (H-2K or H-2D) antigens were also increased. Similar patterns of induction of Ia and H-2 antigens were obtained with supernatants containing IFN-gamma produced by a monkey cell line (COS) that had been transfected with a plasmid bearing the cloned murine IFN-gamma gene. This activity was sensitive to pH 2 and was not present in the supernatant from COS cells that were not transfected with the murine IFN-gamma gene. These results established that IFN-gamma is the T cell-derived molecule that induces the enhanced expression of Ia and H-2 antigens on B cells and macrophages. A major physiologic role of IFN-gamma may be to regulate immune function through the enhanced expression of MHC antigens.     

Anti-obesity effects of resveratrol: comparison between animal models and humans

The prevalence of obesity has increased rapidly during recent years and has reached epidemic proportions. As a result, the scientific community is interested in active biomolecules which are naturally present in plants and foodstuffs and may be useful in body weight management. In recent years, polyphenols have made up one of the most frequently studied groups among these molecules. Numerous studies have been carried out on animals to analyse the potential anti-obesity effects of resveratrol, a non-flavonoid polyphenol, and a general consensus concerning the body-fat-lowering effect of this compound exists. By contrast, studies in humans have been few so far. Moreover, in these studies, the effectiveness of resveratrol is low. The aims of the present review are to summarize the results reported so far on this topic and to justify the differences observed between animals and humans. It seems that the reduced response to resveratrol in humans cannot be attributed to the use of lower doses in humans because the doses that induce body-fat-lowering effects in rodents are in the same range as those used in human studies. With regard to the experimental period length, treatments were longer in animal studies than in human studies. This can be one of the reasons contributing to the reduced responses observed in humans. Moreover, animals used in the reported studies are young while volunteers participating in human studies are adults, suggesting that resveratrol may be more efficient in young individuals. In addition to differences in the experimental designs, metabolic differences between animals and human cannot be discarded.     

Human herpesvirus 7 infection of lymphoid and myeloid cell lines transduced with an adenovirus vector containing the CD4 gene.

It has been reported recently that CD4 is a major component of the receptor for human herpesvirus 7 (HHV-7), which has been newly identified as a T-lymphotropic virus. To investigate further the role of CD4 in HHV-7 infection, we examined the susceptibility to HHV-7 infection of various CD4-negative or weakly positive cell lines into which the cDNA for CD4 was transferred using an adenovirus vector (Adex1CACD4). Of 13 cell lines transduced with Adex1CACD4, including T-lymphoid, B-lymphoid, monocytoid, and myeloid cell lines, one T-lymphoid cell line, one monocytoid cell line, and two cell lines established from the blast crisis of chronic myelogenous leukemia showed high susceptibility to HHV-7 infection. Taken together with the results of previous studies, these data suggest strongly that CD4 is a major component of the binding receptor for HHV-7. This study also shows that HHV-7 may be able to infect CD4-positive hematopoietic precursor cells as well as T lymphocytes.     

Cholesterol esterification as a limiting factor in accumulation of cell cholesterol: a comparison of two J774 macrophage cell lines

It was previously reported by Tabas et al. that J774 macrophages, unlike mouse peritoneal macrophages, accumulate large amounts of cholesteryl esters when incubated with native low-density lipoprotein (LDL). Comparison of the cell line (designated J774A.2) used in those experiments with its parent line (J774A.1) indicates that it is a variant with a greater rate of cholesterol esterification. This large difference in cholesterol esterification was accompanied by only a small difference in rates of LDL uptake and degradation by the J774A.2 line. The J774A.2 cells have become a variant line through either mutation or selection which has enhanced its susceptibility to foam cell formation by its markedly increased ability to esterify cholesterol.