Effects of beta interferon on human fibroblasts at different population doubling levels. Proliferation, cell volume, thymidine uptake, and DNA synthesis

GMP-grade microcarrier and automated closed industrial scale cell production platform for culture of MSCs

Efficient and large-scale expansion of mesenchymal stem/stromal cells (MSCs) has always been a formidable challenge to researchers in cell-based therapies and regenerative medicine. To reconcile major drawbacks of 2D planar culturing system, we innovatively developed an automated closed industrial scale cell production (ACISCP) platform based on GMP-grade microcarrier for culture of umbilical cord-mesenchymal stem/stromal cells (UCMSCs), in accordance with the criteria of stem cell bank. ACISCP system is a fully closed system, which employs different models of vivaSPIN bioreactors (CytoNiche Biotech, China) for scale-up cell culture and vivaPREP (CytoNiche Biotech, China) for automated cell harvesting and cell dosage preparation. To realize industrial scale expansion of UCMSCs, a three-stage expansion was conducted with 1 L, 5 and 15 L vivaSPIN bioreactors. Using 3D TableTrix^® and ACISCP system, we inoculated 1.5 × 10⁷ of UCMSCs into 1 L vivaSPIN bioreactor and finally scaled to two 15 L bioreactor. A final yield of 2.09 × 10¹⁰ cells with an overall expansion factor of 1975 within 13 days. The cells were harvested, concentrated, washed and prepared automatically with vivaPREP. The entire process was realized with ACISCP platform and was totally enclosed. Critical quality attributes (CQA) assessments and release tests of MSCs, including sterility, safety, purity, viability, identity, stability and potency were performed accordingly. The quality of cells harvested from 3D culture on the ACISCP and conventional 2D planar culture counterpart has no significant difference. This study provides a bioprocess engineering platform, harnessing GMP-grade 3D TableTrix^® microcarriers and ACISCP to achieve industrial-scale manufacturing of clinical-grade hMSCs.

The Influence of EGFR Inactivation on the Radiation Response in High Grade Glioma

Lack of effectiveness of radiation therapy may arise from different factors such as radiation induced receptor tyrosine kinase activation and cell repopulation; cell capability to repair radiation induced DNA damage; high grade glioma (HGG) tumous heterogeneity, etc. In this study, we analyzed the potential of targeting epidermal growth factor receptor (EGFR) in inducing radiosensitivity in two human HGG cell lines (11 and 15) that displayed similar growth patterns and expressed the receptor protein at the cell surface. We found that 15 HGG cells that express more EGFR at the cell surface were more sensitive to AG556 (an EGFR inhibitor), compared to 11 HGG cells. Although in line 15 the effect of the inhibitor was greater than in line 11, it should be noted that the efficacy of this small-molecule EGFR inhibitor as monotherapy in both cell lines has been modest, at best. Our data showed a slight difference in the response to radiation of the HGG cell lines, three days after the treatment, with line 15 responding better than line 11. However, both cell lines responded to ionizing radiation in the same way, seven days after irradiation. EGFR inhibition induced radiosensitivity in 11 HGG cells, while, in 15 HGG cells, the effect of AG556 treatment on radiation response was almost nonexistent.

ApoHRP-based assay to measure intracellular regulatory heme

The majority of the heme-binding proteins possess a "heme-pocket" that stably binds to heme. Usually known as housekeeping heme-proteins, they participate in a variety of metabolic reactions (e.g., catalase). Heme also binds with lower affinity to the "Heme-Regulatory Motifs" (HRM) in specific regulatory proteins. This type of heme binding is known as exchangeable or regulatory heme (RH). Heme binding to HRM proteins regulates their function (e.g., Bach1). Although there are well-established methods for assaying total cellular heme (e.g., heme-proteins plus RH), currently there is no method available for measuring RH independent of the total heme (TH). The current study describes and validates a new method to measure intracellular RH. This method is based on the reconstitution of apo-horseradish peroxidase (apoHRP) with heme to form holoHRP. The resulting holoHRP activity is then measured with a colorimetric substrate. The results show that apoHRP specifically binds RH but not with heme from housekeeping heme-proteins. The RH assay detects intracellular RH. Furthermore, using conditions that create positive (hemin) or negative (N-methyl protoporphyrin IX) controls for heme in normal human fibroblasts (IMR90), the RH assay shows that RH is dynamic and independent of TH. We also demonstrated that short-term exposure to subcytotoxic concentrations of lead (Pb), mercury (Hg), or amyloid-β (Aβ) significantly alters intracellular RH with little effect on TH. In conclusion the RH assay is an effective assay to investigate intracellular RH concentration and demonstrates that RH represents ∼6% of total heme in IMR90 cells.

Targeting slow-proliferating ovarian cancer cells

Advanced ovarian cancer has a high rate of recurrence and mortality despite relative chemosensitivity at the time of initial treatment. Conventional chemotherapeutic agents typically target rapidly dividing cells. Disease relapse may therefore result from the survival and later emergence of latent slow-proliferating and/or quiescent cancer cells. We sought to identify drugs that target this cell population and to investigate the influence of these cells on outcome of patients in remission from advanced ovarian cancer. Drugs with increased efficacy against slower proliferating cells were identified using correlation-based screening of 44,657 compounds tested on the NCI-60 panel of cancer cell lines. Validation of candidates was performed in comparison with Cisplatin or Paclitaxel and by manipulation of proliferation rates by serum deprivation. Cytostatic and cytocidal effects were evaluated using MTT assays and active caspase-3 immunocytochemistry. Ki-67 proliferation indices were determined for tumors from 104 patients in remission. UCN-01 efficacy was correlated with longer doubling time among the NCI-60 cell lines (R = 0.54, p < 0.0001) and in a panel of 24 ovarian cancer cell lines (R = 0.42, p = 0.04), whereas this was not the case for Cisplatin (R = -0.10, p = 0.65) and Paclitaxel efficacy correlated with shorter doubling time (R = -0.52, p = 0.009). Cytostatic and cytocidal effects of UCN-01 were increased in serum-deprived cells. A low proliferation index was associated with presence of persistent disease at second-look surgery (p = 0.01) and poor survival (disease-free survival, p = 0.002; overall survival, p = 0.04). These results suggest that targeting quiescent ovarian cancer cells may be a worthwhile therapeutic approach to improving survival of women with ovarian cancer.

p34SEI-1 inhibits doxorubicin-induced senescence through a pathway mediated by protein kinase C-delta and c-Jun-NH2-kinase 1 activation in human breast cancer MCF7 cells

In this study, we describe a novel function of the p34(SEI-1) protein, which is both an oncogenic protein and a positive regulator of the cell cycle. The p34(SEI-1) protein was found to inhibit doxorubicin-induced senescence. We investigated the molecular mechanisms of the inhibitory effect of p34(SEI-1) on senescence. First, we found that the activation of protein kinase C-delta (PKC-delta), which is cleaved into a 38 kDa active form from a 78 kDa pro-form, induced after doxorubicin treatment, was inhibited by p34(SEI-1). Furthermore, p34(SEI-1) induced the ubiquitination of PKC-delta. Yet, there is no interaction between p34(SEI-1) and PKC-delta. We also found that the phosphorylation of c-Jun-NH(2)-kinase 1 (JNK1) induced after doxorubicin treatment was suppressed by p34(SEI-1), but not in JNK2. Consistently, pharmacologic or genetic inactivation of either PKC-delta or JNK1 was found to inhibit doxorubicin-induced senescence. In addition, the genetic inactivation of PKC-delta by PKC-delta small interfering RNA resulted in an inhibition of JNK1 activation, but PKC-delta expression was not inactivated by JNK1 small interfering RNA, implying that the activation of JNK1 could be dependently induced by PKC-delta. Therefore, p34(SEI-1) inhibits senescence by inducing PKC-delta ubiquitination and preventing PKC-delta-dependent phosphorylation of JNK1.

Phase II study of alpha2 interferon in the treatment of the chronic myeloproliferative disorders (E5487): a trial of the Eastern Cooperative Oncology Group

BACKGROUND

In vitro and clinical data suggest a therapeutic role for alpha2 interferon (IFN) in the treatment of the chronic myeloproliferative disorders. Accordingly, a multiinstitutional, Phase II trial of IFN in patients with agnogenic myeloid metaplasia (AMM), essential thrombocythemia (ET), and polycythemia rubra vera (PRV) in the spent phase was initiated. The objectives of this study were 1) to investigate the response rates that may be achieved with IFN in the treatment of patients with these disorders, 2) to estimate the durability of the responses, and 3) to assess the toxicities of IFN in these populations.

METHODS

Enrollment was limited to patients with AMM, ET, or PRV who already had developed 1) anemia or transfusion dependency, 2) thrombocytosis uncontrolled by standard therapy, 3) hemostatic complications, or 4) symptomatic splenomegaly. Initially, patients were started on IFN at a dose of 5 MU/m(2) per day as a subcutaneous injection. After the first 16 patients had been treated, the starting dose of IFN was reduced to 2 MU/m(2) per day because of unexpected toxicities.

RESULTS

IFN demonstrated different levels of efficacy and toxicity in each of the three diseases studied. The overall response rates achieved among the evaluable patients in each category were as follows: ET, 88.2% (n = 17 patients; 1 complete response and 14 partial responses); PRV, 41.7% (n = 12 patients; 1 complete response and 4 partial responses); and AMM, 3.2% (n = 31 patients; 0 complete responses and 1 partial response). Thrombocytosis and leukocytosis were controlled in nearly all patients, with reversal of splenomegaly and resorption of myelofibrosis achieved in fewer patients. The toxicities attributed to IFN differed notably among the three disease groups: patients who had AMM suffered systemic and neurologic toxicities more frequently than patients who had PRV or ET; whereas patients who had ET experienced a greater than expected incidence of hepatic abnormalities, most typically transient elevations of serum amino acid transaminase levels.

CONCLUSIONS

The current study demonstrated the safety and efficacy of IFN in patients with ET, PRV, and AMM. Objective responses and/or disease stabilization were obtained in patients with all three disease entities, including the reversal of splenomegaly and resorption of myelofibrosis in some patients.

Antiproliferative effects of IFN-alpha correlate with the downregulation of nuclear factor-kappa B in human Burkitt lymphoma Daudi cells

Interferon-alpha (IFN-alpha) is known to exhibit antiviral, antiproliferative, and immunomodulatory properties through mechanisms still not fully understood. Nuclear transcription factor-kappaB (NF-kappaB) plays a major role in viral replication, cell proliferation, and immune response. Whether antiproliferative effects of IFN are mediated through suppression of NF-kappaB is not known. We, therefore, examined the relationship between the antiproliferative effects of IFN-alpha and NF-kappaB activity in a human Burkitt lymphoma Daudi cell line. These cells were found to constitutively express high levels of active NF-kappaB that cannot be further activated by tumor necrosis factor (TNF). Treatment of cells with IFN-alpha suppressed the activated NF-kappaB in a dose-dependent manner, with an optimum effect at 10 U/ml in 72 h. Suppression of NF-kappaB correlated with a concomitant decrease in the cytoplasmic levels of IkappaBalpha, the inhibitory protein of NF-kappaB, known to be regulated by NF-kappaB. Downregulation of constitutive NF-kappaB activity correlated with a decrease in cell proliferation by IFN-alpha. Overall, our results suggest that IFN-alpha is a potent suppressor of constitutive NF-kappaB, which may contribute to the inhibition of cell proliferation.

Long term treatment of myeloproliferative disease with interferon-alpha-2b: feasibility and efficacy

BACKGROUND

Recombinant interferon-alpha-2b (rIFN-alpha-2b) has shown therapeutic potential in patients with chronic myelogenous leukemia and other myeloproliferative disorders (MPDs), including the ability to suppress the abnormal hematopoietic clone and to reverse myelofibrosis. This study was conducted to evaluate further the efficacy and safety of rIFN-alpha-2b in a large group of patients with polycythemia vera, essential thrombocythemia, or agnogenic myeloid metaplasia and to determine maintenance of response after treatment discontinuation.

METHODS

Induction therapy began with subcutaneous rIFN-alpha-2b at 5.0 x 10(6) IU/day until a complete or partial response was achieved. Treatment continued at 2.5 x 10(6) IU/day until spleen size and hematologic parameters stabilized.

RESULTS

Fifty-four patients were studied (median follow-up, 7.3 years); at last follow-up 27 patients still were participating (median follow-up, 3.8 years). Twenty-four of 24 patients with thrombocythemia (100%) and 14 of 14 patients with hyperleukocytosis (100%) responded to induction therapy, whereas 26 of 39 patients (67%) experienced > 10% decrease in splenomegaly. Thirty-nine of 54 patients (72%) maintained response for a median of 39 weeks after withdrawal of rIFN-alpha-2b; repeat courses in previously responding patients produced similar results. The survival rate at 8 years was 60%. rIFN-alpha-2b generally was well tolerated, but toxicity caused treatment withdrawal in 7 patients (13%).

CONCLUSIONS

rIFN-alpha-2b can produce regression of splenomegaly and control of leukocyte and platelet counts in patients with MPD. These responses are sustained for prolonged periods in some patients after therapy discontinuation. In patients with recurrent disease, disease control can be attained again with reinitiation of rIFN-alpha-2b. Therefore this therapy should be an important treatment consideration for patients with MPD.

In vivo levels and in vitro production of interferon-gamma in fibrosing interstitial lung diseases

The in vivo role of interferons in the development of fibrosis is not fully understood but it is known that interferons can suppress fibroblast proliferation and collagen synthesis in vitro. We have recently demonstrated that in a group of patients with sarcoidosis having predominant pulmonary involvement, patients with the highest levels of circulating interferon-gamma (IFN-gamma) more frequently resolved on corticosteroids, suggesting that they had a less 'fibrotic' component to their disease. We now report that in two other diseases, where the tendency to develop pulmonary fibrosis is greater than in sarcoidosis, namely cryptogenic fibrosing alveolitis (CFA) and fibrosing alveolitis associated with the systemic connective tissue disease progressive systemic sclerosis (FA + PSS), very few patients have elevations in IFN-gamma in their serum. However, as in sarcoidosis, those with the highest levels responded to corticosteroids (P less than 0.05). Attempts to measure IFN-gamma levels in the lungs, using cell-free bronchoalveolar lavage (BAL) fluid supernatants, were negative in all the study groups, suggesting that these samples may be inadequate for such studies. To investigate whether there might be an intrinsic defect in T lymphocyte function associated with predisposition to fibrosing lung diseases, we then investigated the in vitro production of IFN-gamma by lymphocytes separated from the blood of 18 untreated patients (six with CFA, six with FA + PSS and six with sarcoidosis). IFN-gamma production was impaired in 10 (56%) (two with CFA, four with FA + PSS and four with sarcoidosis). A higher proportion of the fibrosing alveolitis patients (CFA or FA + PSS) with impaired IFN-gamma production have subsequently shown spontaneous lung functional deterioration. These findings suggest that impaired IFN-gamma release might be a potentiating factor in the pathogenesis of these fibrosing lung diseases.

Interleukin-6 and 12-O-tetradecanoyl phorbol-13-acetate act synergistically in inducing cell-cell separation and migration of human breast carcinoma cells

Interleukin-6 (IL-6) causes an epithelial to fibroblastoid conversion and an increase in the motility of human ductal breast carcinoma cell lines ZR-75-1 and T-47D. Although IL-6 decreases DNA synthetic activity in these cell lines, the IL-6-induced alterations in cell shape and motility occur independently of inhibition of DNA synthesis per se. Whereas tumor necrosis factor alpha (TNF-alpha) inhibits DNA synthesis in T-47D cells, it does not cause an epithelial-fibroblastoid conversion or other major morphological changes and does not increase cell motility; TNF-alpha rapidly lyses a majority of ZR-75-1 cells. Furthermore, the DNA synthesis inhibitors 5-fluoro-2'-deoxyuridine (FUDR) and methotrexate (MTX) also do not cause effects mimicking the action of IL-6 on cell structure and motility. Transforming growth factors alpha and beta 1, acidic and basic fibroblast growth factors, epidermal growth factor, and insulin-like growth factor-1 (TGF-alpha, TGF-beta 1, aFGF, bFGF, EGF, and IGF-1) have little or no effect on breast cancer cell morphology, which serves to exclude the possibility that the IL-6-induced changes are a consequence of induction of these growth factors by IL-6. 12-O-tetradecanoyl phorbol-13-acetate (TPA) but not 8-bromoadenosine 3',5'-cyclic monophosphate (Br-cAMP) induces changes in the morphology and associative behavior of ZR-75-1 cells that are similar but not identical to those caused by IL-6. The TPA-induced alterations are not blocked by anti-IL-6 neutralizing antibodies; staurosporine inhibits the TPA-induced cell alterations but not those induced by IL-6. IL-6 and TPA used together have a phenotypic effect that greatly exceeds that of either agent alone and results in extensive cell scattering in less than 1 day. These findings are consistent with the hypothesis that IL-6 and TPA induce similar morphological changes and cell scattering via independent pathways.

Homoeostatic imbalance during cellular ageing: altered responsiveness

The inability of normal cells to maintain themselves for ever is a reflection of homoeostatic imbalance and a progressive failure of maintenance. Ageing cells respond less to growth stimulants whereas they show increased sensitivity to toxic agents including antibiotics, phorbol esters, radiation and other physical stresses. No major quantitative and qualitative defects in the receptor systems have been detected that could explain the reasons for altered responsiveness during ageing. Random metabolic defects in the processes involved in maintaining homoeostasis may be critical for causing homoeostatic imbalance, cellular ageing and death.

Immunomodulatory and antiproliferative effect of recombinant alpha, beta, and gamma interferons on cultured human malignant squamous cell lines, SCL-1 and SW-1271

Two different human malignant squamous cell lines (SCL-1 and SW-1271) and normal human foreskin fibroblasts were treated with recombinant human alpha, beta, and gamma interferons. HLA-DR expression was induced in a concentration-dependent fashion only on the SCL-1 cells treated with recombinant human gamma interferon (r-IFN-gamma) (10(2)-10(3) U/ml). No HLA-DR expression was observed with alpha or beta interferon on either malignant squamous cell line, nor with gamma interferon on SW-1271 cells. All three interferons reduced the number of malignant cells growing in culture but had no effect on the fibroblasts. There was a concentration-dependent growth-inhibitory response of the malignant cells by the interferons (dose range 1-10(3) U/ml; 7.1 X 10(-12) M to 7.1 X 10(-9) M). The SCL-1 cells were 10(2) more sensitive (based on weight) to the antiproliferative effects of gamma interferon than alpha or beta interferon. A brief (30-min) exposure of the SCL-1 cells to r-IFN-gamma (10(2) and 10(3) U/ml) produced approximately the same inhibition of cell growth as continuous exposure over a 2-week period. The SW-1271 cells were equally sensitive to alpha, beta, and gamma interferons. However, the maximal inhibitory effect on SW-1271 cells was less than that observed for the SCL-1 cells. Combining beta and gamma interferon resulted in cytotoxicity with SCL-1 cells and additive cytostatic effect on the SW-1271 cells. These additional malignant cell lines with their different sensitivities to alpha, beta, and gamma interferons may prove useful in studying the mechanisms of action of various interferons.

Chromosomal aberrations in muntjac cells resulting from exposure to interferon

Cells of the Indian deer (Muntiacus muntjac) are sensitive to the antiviral and antiproliferative action of human beta-interferon (beta-IFN). Because of their low diploid chromosome number and readily identifiable chromosomes, they provide a convenient model system in which to test for the ability of IFN treatment to result in chromosome abnormalities. Increases in the frequencies of chromosome gaps and breaks have been observed after 72 h of treatment with IFN at a concentration of 100 U/ml. At IFN concentrations of 10-100 U/ml, there is a higher proportion of aberrations in the X chromosome than would be expected in a random distribution. At 1,000-1,700 U/ml IFN, there is an increase in the proportion of cells with multiple abnormalities over that observed at 0-100 U/ml IFN, and the distribution of aberrations appears to be random.

The effects of treatment with human beta-interferon on the stimulation of thymidine uptake and DNA synthesis by colchicine in human fibroblasts

The marked inhibition by beta-interferon (IFN) of colchicine-induced incorporation of [3H]-thymidine into DNA of human fetal lung fibroblasts reflects inhibition of uptake of labeled precursor, rather than an effect on DNA synthesis per se. The percent of cells in S phase as measured with flow cytometry was unchanged by a concentration of IFN that reduced the uptake of labeled thymidine by 50% at 30 h after treatment.