Effects of apatite and wollastonite containing glass-ceramic powder and two types of alumina powder in composites on osteoblastic differentiation of bone marrow cells

Previously we developed a composite consisting of apatite and wollastonite containing glass-ceramic (AW-GC) powder and bisphenol-a-glycidyldimethacrylate (Bis-GMA)-based resin (designated AWC), and demonstrated that AWC showed direct contact with living bone. Another new composite consisting of mainly the delta-crystal phase of alumina bead powder and Bis-GMA-based resin (designated ABC) was developed. Although alumina ceramics are bioinert and a composite filled with the pure alpha-crystal phase of alumina powder (designated alphaALC) did not allow direct bone formation in vivo, ABC was shown to have excellent osteoconductivity. One purpose of this study was to investigate whether AW-GC powder in a composite promotes osteoblastic differentiation of rat bone marrow cells as AW-GC bulk did. Another purpose was to evaluate the effects of the delta-crystal phase of alumina powder in a composite on osteoblastic differentiation. In a cell culture with dexamethasone, alkaline phosphatase (AP) activity at both days 7 and 14, and the levels of osteocalcin mRNA and alpha1(I) collagen mRNA at day 14 and osteopontin mRNA at day 7, were highest on AWC, followed by ABC, and finally alphaALC. Scanning electron microscopy showed more abundant mineralized globules and a fibrous collagen matrix on AWC at day 14, followed by ABC. In a cell culture without dexamethasone, AP activity at both days 7 and 14, and the level of osteopontin mRNA at day 7, were higher on ABC than on any other composite, whereas osteocalcin mRNA could not be detected. These results indicate that AW-GC powder in a composite promotes osteoblastic differentiation of bone marrow cells intensively when supplemented with dexamethasone. The delta-crystal phase of alumina powder in a composite promotes greater osteoblastic differentiation than the alpha-crystal phase of alumina powder.

Oncoprotein 18 overexpression increases the sensitivity to vindesine in the human lung carcinoma cells

BACKGROUND

Oncoprotein 18 (op18) was first isolated as a molecule overexpressed in several malignant cells, suggesting a function of op18 in malignant processes, such as differentiation in hematologic malignancies, op18 also was found to enhance microtubule deassembly in the cells. Antimitotic agents that bind to tubulin have been used for chemotherapy to treat solid tumors, such as lung carcinoma. Vinca alkaloids, such as vindesine and vincristine, have commonly been used for chemotherapy of nonsmall cell lung carcinoma. The authors examined the role of op18 in the sensitivity of human lung carcinoma cells to antimitotic agents.

METHODS

Expression of op18 mRNA was detected in all 17 lung carcinoma cell lines tested by Northern blotting. Oncoprotein 18 cDNA was transfected to SBC-3 human lung carcinoma cells, and the stable transfectants, SBC-3/op1-3, were isolated. The sensitivity of these transfectants against antimitotic agents were examined by the MTT assay in vitro. Cell cycle distribution of the transfectants on DNA histogram was analyzed by flow cytometry.

RESULTS

Oncoprotein 18-transfected cells showed higher sensitivity to vindesine and vincristine, but not to taxanes. Vindesine-exposure increased the G2/M population of the cell cycle in the Mock transfectants, but not in SBC-3/op1, suggesting that the cell cycle dynamics were altered by op18 expression in SBC-3/op1.

CONCLUSION

Oncoprotein 18 expression is associated with lung carcinoma cell sensitivity to vindesine and may be able to serve as a surrogate marker for the chemosensitivity to Vinca alkaloids in human lung carcinomas.

Upregulated expression of angiogenesis genes and down regulation of cell cycle genes in human colorectal cancer tissue determined by cDNA macroarray

The differential expression of hundreds of tightly, transcriptionally controlled genes in isolated human colorectal cancer and respective normal mucosa from two patients was analyzed by the cDNA macroarray technique. mRNA prepared from the colorectal cancer tumors was compared with 588 genes spotted onto the filter. Case A showed down-regulation of the expression of cell-cycle-related genes including cyclins, cyclin-dependent kinase (CDK) 2, and CDK-activating kinase, as compared with normal mucosa from the same patient. The tumors showed up-regulation of expression of angiogenesis-related genes such as type II cytoskeletal 8 keratin, metalloproteinase subtypes, VEGF, and bFGF, to over 5-fold the levels in normal mucosa. Thus, colorectal carcinoma tissues are characterized by the upregulation of molecules related with angiogenesis. These results suggest that angiogenesis-related molecules are suitable candidates for target-based therapies for colorectal cancer patients. In case B, the largest difference in expression between the tumor and mucosal tissues was observed in the MMP-1 gene. In contrast to the first case, there was no increase in expression of angiogenesis-related molecules or decrease in expression of cell-cycle-regulatory molecules. The expression profile was quite different between these two patients. This approach may eventually provide a mean of selecting target-based drugs in individual colon cancer patients.

Genetic background in patients with acute myocardial infarction

The renin-angiotensin system is believed to play important roles in the development of acute myocardial infarction, and gene polymorphisms may also be involved. To investigate the genetic background in patients with acute myocardial infarction, we performed a case control study in a Japanese population. The study included 150 patients with acute myocardial infarction and 150 healthy, age- and sex-matched controls. We examined polymorphisms of angiotensin II type 1 receptor (1 166 A / C), type 2 receptor (3123 C / A), and bradykinin B2 receptor (-58 T / C) in these subjects. The allelic frequencies of angiotensin II type I receptor C and angiotensin II type 2 receptor A were significantly higher in the acute myocardial infarction subjects than in the control subjects, and this tendency was more significant in the younger patients. The combined ratios of angiotensin II type 1 receptor C and type 2 receptor A alleles in patients under 64 years old were significantly higher than in their older counterparts. However the total numbers of conventional coronary risk factors (hypertension, hypercholesterolemia, diabetes mellitus, and smoking) in individual subjects were not significantly different between younger and older patients. These polymorphisms were found to be involved in the development of acute myocardial infarction, particularly in the younger patients, and it was concluded that the incidence of acute myocardial infarction might be reduced by management from the genotypes.

In vitro synergistic interactions between the cisplatin analogue nedaplatin and the DNA topoisomerase I inhibitor irinotecan and the mechanism of this interaction

Among the numerous clinical regimens used in combination chemotherapy, synergy is particularly marked in combinations containing cisplatin (CDDP). However, the clinical use of CDDP is sometimes limited due to its nephrotoxicity. Nedaplatin (NDP) is a second-generation platinum complex with reduced nephrotoxicity that may substitute for CDDP or even surpass it for use in combination with other drugs. We investigated the effects of combinations of NDP and other anticancer drugs on the growth of human small cell lung cancer cells (SBC-3) and non-small cell lung cancer cells (PC-14) using a three-dimensional analysis model. Among the combinations tested, the combination of NDP and irinotecan (CPT-11) showed the most marked synergistic interaction, and the synergism has also been observed against PC-14 cells. With regard to treatment schedule, a remarkable synergistic interaction was produced by concurrent exposure to NDP and CPT-11. On the other hand, sequential exposure to the two drugs led only to additivity. To analyze the interaction between the drugs, the effect of NDP on the 7-ethyl-1-hydroxy-CPT (the active form of CPT-11)-induced inhibitory effect on DNA topoisomerase I was examined. The topoisomerase I-inhibitory effect of 7-ethyl-1-hydroxy-CPT was enhanced 10-fold in the presence of NDP at microgram/milliliter concentrations. These biochemical interactions might be responsible for the synergistic interaction between NDP and CPT-11. These results suggest that the combination of NDP with CPT-11 may be clinically useful for the chemotherapy of lung cancer.

The effect of alkali- and heat-treated titanium and apatite-formed titanium on osteoblastic differentiation of bone marrow cells

This study was based on the hypothesis that osteogenesis is enhanced by growth of osteogenic cells on an apatitic surface. To test this hypothesis, the behavior of rat bone marrow cells on these surfaces was examined: commercially pure titanium (Cp Ti), alkali- and heat-treated titanium (AH Ti), and AH Ti incubated in a simulated body fluid to deposit crystalline hydroxyapatite on the surface (Ap Ti). The alkaline phosphatase (ALP) activity of the cells cultured on Ap Ti was significantly higher at day 7 and day 14 than the ALP activity observed for the other titanium surfaces. At day 14, the ALP activity on AH Ti was significantly increased compared with the ALP activity on Cp Ti. The amount of DNA per well increased nearly in parallel for each titanium. However, northern blot analysis at day 14 revealed that expression of osteocalcin and alpha1(I) collagen mRNA was higher in the cells cultured on Ap Ti than the cells cultured on AH Ti. The cells cultured on Cp Ti showed the lowest mRNA levels. After 7 days of cell-free culture in medium supplemented with 15% serum, X-ray photoelectron spectroscopy (XPS), and thin-film X-ray diffraction (TF-XRD) analysis showed that calcium phosphate had been deposited on the AH Ti (resulting in an increase in thickness with time). No phosphate was detected on the Cp Ti, even after day 14. This study indicates that Ap Ti provides the most favorable conditions for differentiation of bone marrow cells, and, at a later stage, AH Ti also provides favorable conditions, perhaps because of the formation of a surface layer of calcium phosphate. This potential for apatite formation may play an important role in osteoblastic differentiation.

Corneal infection of herpes simplex virus type 2--induced neuronal apoptosis in the brain stem of mice with expression of tumor suppressor gene (p53) and transcription factors

To understand the mechanism of neuronal apoptosis induced by herpes simplex virus (HSV) infection in vivo, the distribution of viral antigen, the appearance of apoptotic bodies, and the expressions of the tumor suppressor gene p53 and several transcription factors such as c-fos, c-jun and NF-kappaB were examined immunohistochemically and histopathologically after corneal infection of mice with HSV type 2 strain 186. Five days after HSV infection, viral antigen was diffusely detected in the corneal epithelium, the trigeminal ganglion and the pars caudalis of the spinal trigeminal nucleus. Neuronal apoptosis was observed in the brain stem ipsilateral to the HSV-infected side with the immunoreactivities of c-fos, c-jun, NF-kappaB and p53. Dual-labeling immunohistochemical studies revealed that almost all of the viral antigen-positive neurons and glia in the brain stem also showed p53 immunoreactivity. On the other hand, no neuronal apoptosis but only with the expression of c-jun was found in the trigeminal ganglion. Our results suggest that the different expression of transcription factors between the brain stem and the trigeminal ganglion may influence the neuronal apoptosis induced by HSV infection.

Mechanism of action of aragusterol a (YTA0040), a potent anti-tumor marine steroid targeting the G(1) phase of the cell cycle

Aragusterol A (YTA0040), isolated from the Okinawan marine sponge of the genus Xestospongia, is a potent anti-tumor marine steroid that possesses a unique structural component. This compound showed broad-spectrum anti-proliferative activity against a panel of 14 human cancer cell lines (IC(50) = 0.01-1.6 microM). P-glycoprotein-mediated, multidrug-resistant cells showed cross-resistance to YTA0040 cells, whereas cisplatin-resistant non-small-cell lung-cancer (NSCLC) sublines showed a collateral sensitivity to YTA0040. In transplantable murine tumor models, YTA0040 displayed a broad spectrum and high degree of anti-tumor activity when administered i.p. or p.o. (life span T/C = 135-234%). In P388 murine leukemia cells, YTA0040 caused dose- and time-dependent suppression of nucleic acid and protein synthesis, with protein synthesis being more potently and rapidly inhibited than nucleic acid synthesis. Flow-cytometric analysis revealed that YTA0040 blocked the entry of human NSCLC-derived A549 cells into S phase, leading to arrest in the G(1) phase of the cell cycle. Western blot analysis demonstrated that YTA0040 caused a dose-dependent decrease in the levels of expression of hyperphosphorylated pRb and cyclin A in A549 cells. The level of p53 protein expression was decreased by YTA0040 treatment. A higher concentration of YTA0040 down-regulated the levels of expression of CDK2, CDK4, cyclin D1 and cyclin E. These findings indicated that YTA0040 arrested human NSCLC cells in late G(1) phase of the cell cycle through inhibition of pRb phosphorylation. Inhibition of pRb phosphorylation by YTA0040 resulted from down-regulation of levels of expression of the CDKs and cyclins involved in the G(1)/S transition and not from induction of p53 and/or the CDK inhibitor p21.

A computational model for quantitative analysis of cell cycle arrest and its contribution to overall growth inhibition by anticancer agents

Most anticancer agents induce cell cycle arrest (cytostatic effect) and cell death (cytotoxic effect), resulting in the inhibition of population growth of cancer cells. When asynchronous cells are to be examined, the currently used flow cytometric method can not provide checkpoint-specific and quantitative information on the drug-induced cell cycle arrest. Hence, despite its significance, no good method to analyze in detail the mechanism of cell cycle arrest and its contribution to overall growth inhibition induced by an anticancer agent has yet been established. We describe in this study the development of a discrete time (Markov model)-based computational model for cell cycle progression / arrest with transition probability (TP(i)) as a model parameter. TP(i) was calculated using model equations that include easily measurable parameters such as the fraction of cells in each cell cycle phase and population doubling time. The TP(i) was then used to analyze checkpoint-specific and quantitative changes in cell cycle progression. We also used TP(i) in a Monte-Carlo simulation to predict growth inhibition caused by cell cycle arrest only. Human SCLC cells (SBC-3) exposed to UCN-01 were used to validate the model. The model-predicted growth curves agreed with the observed data for SBC-3 cells not treated or treated at a cytostatic concentration (0.2 mM) of UCN-01, indicating validity of the present model. The changes in TP(i) indicated that UCN-01 reduced the G(1)-to-S transition rate and increased the S-to-G(2) / M and G(2) / M-to-G(1) transition rates of SBC-3 cells in a concentration- and time-dependent manner. When the model-predicted growth curves were compared with the observed data for cells treated at a cytotoxic concentration (2 mM), they suggested that 22% out of 65% and 32% out of 73% of the growth inhibition could be attributed to the cell cycle arrest effect after 48 h and 72 h exposure, respectively. In conclusion, we report here the establishment of a novel method of analysis that can provide checkpoint-specific and quantitative information about cell cycle arrest induced by an anticancer agent and that can be used to assess the contribution of cell cycle arrest effect to the overall growth inhibition.

Increased expression levels of p53 correlate with good response to cisplatin-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the tumor suppressor gene p53 in non-small cell lung cancer (NSCLC) correlates with chemotherapeutic response, resected tumors from 18 patients with recurrent lung cancer who had undergone complete resection and received chemotherapy after the initial tumor recurrence were subjected to p53 immunostaining. Histological examination of the resected tumors revealed 11 adenocarcinomas, 6 squamous cell carcinomas and one adenosquamous cell carcinoma. Group 1 was </=50% (n=9) and group 2 >50% (n=9) p53-immunopositive. All patients received cisplatin-based chemotherapy after recurrence. No patient in group 1 achieved response to chemotherapy whereas 2 and 3 in group 2 achieved complete and partial responses, respectively. The chemotherapy response rate of group 2 (56%) was significantly higher than that of group 1 (0%, p=0.009). The times to reoccurrence after tumor resection of group 2 was significantly better than that of group 1 (log-rank p=0.019, Wilcoxon p=0.042), and survival after chemotherapy of group 2 was also significantly better than that of group 1 (log-rank p=0.023, Wilcoxon p=0.034). It is suggested that high p53 expression levels in tumors correlate with both good response to cisplatin-based chemotherapy and good survival of patients with advanced NSCLC.

Guillain-Barré syndrome in a child with systemic lupus erythematosus and anti-Ro/SSA and anti-La/SSB autoantibodies

We report a 9-year follow-up of a girl with systemic lupus erythematosus (SLE) and probable Sjögren's syndrome. At the age of 7 years, the patient developed a chilblain-like eruption with features of SLE, including leucopenia, oral ulcers, positive rheumatoid and antinuclear antibodies and positive anti-dsDNA, anti-Ro/SSA and anti-La/SSB antibodies. At the age of 13 years she developed Guillain-Barré syndrome, which completely resolved with aggressive treatment, including high-dose corticosteroids and the use of plasma exchange followed by intravenous gammaglobulin.

Problems in the development of target-based drugs

Numerous molecular targets of cancer chemotherapy have been identified based on progress made in molecular biology, and new categories of anticancer drugs have been developed. These include inhibitors for signal transduction, cyclin-dependent kinase, angiogenesis, and matrix metalloproteinase, gene therapy, etc. They are variously called target-based drugs, noncytotoxic drugs, or cytostatic drugs. Such drugs have interesting mechanisms of action and appear promising. However, preclinical and clinical evaluations are difficult. Some drugs have a direct antitumor effect, with demonstrated tumor shrinkage. Others show no direct cytotoxicity. The majority of recent phase I trials have evaluated the maximum tolerated dose, pharmacokinetics, adverse events, and antitumor effect. Unusual, unacceptable toxicities have been noted with some target-based drugs. Few phase I trials or preclinical studies have attempted to demonstrate target inhibition. So far very few studies has shown that there is a correlation between target inhibition and antitumor effect. In general, phase II studies are undertaken with compounds such as trastuzumab which have direct antitumor activity. Phase III trials of most target-based drugs are undertaken immediately after phase I studies since the design of appropriate phase II studies is difficult. The ultimate endpoint of phase III trials of target-based drugs is the same as that for cytotoxic drugs, such as improved cure and survival rates.

Transfer of iron-sulfur cluster from NifU to apoferredoxin

Iron-sulfur proteins are present in a wide variety of organisms and are known to play important physiological roles, not only in electron transfer and metabolic reactions, but also in transcriptional regulation. However, little is known about how iron-sulfur clusters themselves are synthesized and assembled within polypeptides. Here we show that a [2Fe-2S] cluster-containing NifU of cyanobacterium Synechocystis PCC6803, SyNifU, possesses the ability to deliver its [2Fe-2S] cluster to an apoferredoxin without the aid of other proteinaceous or nonproteinaceous factor(s). Upon delivery the reconstituted holoferredoxin regained electron transfer ability. The [2Fe-2S] cluster contained within SyNifU was labile upon exposure to the iron-chelating reagent EDTA, suggesting that the iron-sulfur cluster is abnormally exposed to solvent. We propose that NifU serves as a scaffold for iron-sulfur cluster assembly and functions as a mediator for iron-sulfur cluster delivery.

Developmental changes in the spatial expression of genes involved in myosin function in Dictyostelium

We analyzed the spatial expression patterns of the genes involved in myosin function by in situ hybridization at the tipped aggregate and early culmination stages of Dictyostelium. Myosin heavy chain II mRNA was enriched in the anterior prestalk region of the tipped aggregates, whereas it disappeared from there and began to appear in both upper and lower cups of the early culminants. Similarly, mRNAs for essential light chain, regulatory light chain, myosin light chain kinase A, and myosin heavy chain kinase C were enriched in the prestalk region of the tipped aggregates. However, expression of these genes was distinctively regulated in the early culminants. These findings suggest the existence of mechanisms responsible for the expression of particular genes.

Activation-induced apoptosis of peripheral lymphocytes treated with 7-hydroxystaurosporine, UCN-01

7-hydroxystaurosporine (UCN-01) is a new anticancer agent which exerts an inhibitory effect on cell cycle check points and is currently under phase I clinical trials in US and Japan. Preliminary clinical data indicated that UCN-01 remained in plasma at high concentrations for long periods of time. This unavoidable high plasma drug exposure is likely to lead to hematological toxicities in patients. In the present study, cultured human peripheral blood lymphocytes (PBLs) were used to evaluate the possible hematological toxicities of UCN-01 treatment. UCN-01 induces apoptosis, and the induction of apoptosis-related surface markers were also examined to investigate the involvement of these molecules in UCN-01-induced apoptosis in PBLs. In vitro viability of PBLs was decreased by high dose of UCN-01 (25 microM, 3-day exposure). This effect of UCN-01 was significantly suppressed by the presence of human serum, suggesting that some specific inhibitory factor(s) in human serum may antagonize the lympholytic effect of UCN-01. The percentage of annexin V-positive PI-negative cells increased with exposure to UCN-01 in a time- and dose-dependent manner; by up to 30.3% after exposure to 25 microM UCN-01 for 3 days. At the same time, the expression of both interleukin-2 receptor (IL-2R, CD25) and Fas (CD95), analyzed by flow cytometry, was induced. Con A-stimulated PBLs were more sensitive to UCN-01-induced apoptosis than non-stimulated lymphocytes and UCN-01 increased the sFas-L released into culture medium from con A-stimulated PBLs. Therefore, lymphocyte depletion mediated by activation-induced apoptosis is likely to occur in patients treated with UCN-01 at high doses.

Roles of ICAM-1 for abnormal leukocyte recruitment in the microcirculation of bleomycin-induced fibrotic lung injury

To assess the importance of endothelial intercellular adhesion molecule-1 (ICAM-1) in microvascular leukocyte kinetics in diseased lungs, we investigated the transitional changes in ICAM-1 expression, vascular diameter, and leukocyte behavior in rat pulmonary microcirculation during the development of acute lung injury (ALI) and chronic fibrosis (FIB) evoked by bleomycin (BLM). Observations were made in the isolated perfused lung with a real-time confocal laser luminescence microscope. Microvascular cell kinetics were evaluated by measuring the behavior of fluorescence- labeled leukocytes and erythrocytes in the presence or absence of anti-ICAM-1 monoclonal antibody (1A29). Arteriolar ICAM-1 showed little change at any time after BLM treatment. Venular ICAM-1 was first enhanced at the initial phase of ALI followed by the second upregulation at the early phase of FIB. Capillary ICAM-1 showed a sustained increase at both ALI and FIB. Arteriolar and venular diameters were not altered but capillary diameter decreased during ALI and early FIB stages. Although firm adherence of leukocytes to arteriolar and venular walls was not observed, rolling leukocytes were increased in venules both at the initial phase of ALI and at the early phase of FIB. The leukocyte rolling in venules correlated well with transitional changes in ICAM-1 and was inhibited by 1A29. Sustained entrapment of leukocytes in capillaries was attributed to changes in vascular diameter as well as augmented ICAM-1. In conclusion, ICAM-1 plays an important role in microvascular leukocyte recruitment in both ALI and FIB in the BLM-injured lung.

Increased expression levels of cyclin-dependent kinase inhibitor p27 correlate with good responses to platinum-based chemotherapy in non-small cell lung cancer

In order to determine whether expression of the cyclin-dependent kinase inhibitor p27 in non-small cell lung cancer (NSCLC) correlates with chemotherapeutic response, resected tumors from 22 patients with recurrent lung cancer who had undergone complete resection and received chemotherapy after the initial tumor recurrence were subjected to p27 immunostaining. Histological examination of the resected tumors revealed 14 adenocarcinomas, 7 squamous cell carcinomas and one adenosquamous cell carcinoma. Fifty percent or less and over 50% of the cells in the resected tumors of 11 patients each (groups 1 and 2, respectively) were p27-immunopositive. All but one patient received platinum-based chemotherapy after recurrence. Only one in group 1 achieved a partial response (PR) in chemotherapy whereas 2 and 4 in group 2 achieved complete and PRs, respectively. The chemotherapy response rate of group 2 (54%) was significantly higher than that of group 1 (9%, p=0.022). The times to recurrence after tumor resection of the 2 groups did not differ significantly (log-rank p=0.23, Wilcoxon p=0. 32), but survival after chemotherapy of group 2 was significantly better than that of group 1 (log-rank p=0.045, Wilcoxon p=0.028). It is suggested that high p27 expression levels in tumors may predict the good responses to platinum-based chemotherapy for NSCLC.

[Conquering drug resistance in lung cancer]

The emergence of drug resistance of the tumors is the critical problem in lung cancer. The multifactorial mechanisms of cisplatin resistance are major problems. The reversal agents against MDR have been evaluated clinically. Increased adverse effects and modulation of pharmacokinetics in combined with cytotoxic drugs are the problems in clinical setting. The new ABC transporters related with MDR were cloned and characterized. Modulators for these transporters could be evaluated their clinical efficacy. High-frequent mutations of beta-tubulin in clinical samples are reported as a predictive marker for paclitaxel. Target-based drugs might conquer the resistance to conventional drugs. Prediction of the drug sensitivity and resistance in each patient will be expected using high-throghput gene screening system.

Ectopic p16(ink4) expression enhances CPT-11-induced apoptosis through increased delay in S-phase progression in human non-small-cell-lung-cancer cells

A tumor-suppressor gene, p16(INK4), which is deleted or mutated in tumors, regulates cell-cycle progression through a G(1)-S restriction point by inhibiting CDK4(CDK6)/cyclin-D-mediated phosphorylation of pRb. We have found that ectopic p16(INK4) expression increased cellular sensitivity of human non-small-cell-lung-cancer (NSCLC) A549 cells to a selective growth-inhibitory effect induced by the topoisomerase-I inhibitor 11, 7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxy camptothecin (CPT-11) in vitro. In this study, we observed enhanced apoptosis characterized by DNA fragmentation in A549 cells transfected with p16(INK4) cDNA (A549/p16-1) and treated with CPT-11. This apoptosis was suppressed by the inhibitor of interleukin-1beta-converting enzyme (ICE/caspase-1) or ICE-like proteases, Z-Asp-CH2-DCB, as determined by DNA fragmentation and proteolytic cleavage of poly(ADP-ribose) polymerase, a natural substrate for CPP32/caspase-3. In A549/p16-1 cells, cytosolic peptidase activities that cleaved Z-DEVD-7-amino-4-trifluoromethylcoumarin increased during CPT-11-induced apoptosis and were suppressed by a highly specific caspase-3 and caspase-3-like inhibitor, Z-DEVD-fluoromethylketone. These findings indicate that p16(INK) is positively involved in the activation pathway of the caspase-3 induced by CPT-11. The increased delay in S-phase progression and subsequent induction of apoptosis were observed in CPT-11-treated A549/p16-1 cells on the basis of DNA histograms. Specific down-regulation of the cyclin-A protein level in A549/p16-1 cells was observed after CPT-11-treatment, whereas cyclin B, cdk2, and cdc2 protein levels were unaffected. These results suggest that ectopic p16(INK4) expression inappropriately decreases cyclin A and thereby terminates CPT-11-induced G(2)/M accumulation, which is followed by increased apoptosis in p16(INK4)-expressing A549 cells.

Increased expression of the MRP5 gene is associated with exposure to platinum drugs in lung cancer

To investigate the role of the multidrug resistance-associated protein (MRP1) homologue MRP5 in relation to platinum drug resistance, we examined the steady-state levels of the mRNAs for MRP5 in both lung cancer cell lines and peripheral mononuclear cells (PMN) after exposure to platinum drug and in normal lung and lung cancer tissue specimens. Firstly, we examined MRP5 gene expression levels in 80 autopsy samples (40 primary tumors and 40 corresponding normal lung tissues) from 40 patients who had died from lung cancer. Next, we monitored MRP5 gene expression levels within 24 hr in both lung cancer cell lines incubated with cisplatin and in PMN from 10 previously untreated lung cancer patients after carboplatin administration alone. The MRP5 gene expression levels were assessed by quantitative reverse transcription polymerase chain reaction or RNase protection assay. The MRP5 expression levels in normal lung tissues and in tumors from patients exposed to platinum drugs during their lifetime were significantly higher than those in tissues from non-exposed patients. On the other hand, the MRP5 expression levels were not rapidly induced by platinum drugs either in lung cancer cell lines or in PMN within 24 hr. Our results suggest that increased expression levels of the MRP5 gene are associated with exposure to platinum drugs in lung cancer in vivo and/or the chronic stress response to xenobiotics.

Effect of steroid on hyperoxia-induced ICAM-1 expression in pulmonary endothelial cells

Intercellular adhesion molecule-1 (ICAM-1) of the vascular endothelium plays a key role in the development of pulmonary oxygen toxicity. We studied the effect of steroid on hyperoxia-induced ICAM-1 expression using cultured endothelial cells in vitro. Human pulmonary artery endothelial cells (HPAECs) were cultured to confluence, and then the monolayers were exposed to either control (21% O(2)-5% CO(2)) or hyperoxic (90% O(2)-5% CO(2)) conditions with and without a synthetic glucocorticoid, methylprednisolone (MP). MP reduced hyperoxia-induced ICAM-1 and ICAM-1 mRNA expression in a dose-dependent manner. Neutrophil adhesion to hyperoxia-exposed endothelial cells was also inhibited by MP treatment. In addition, MP attenuated hyperoxia-induced H(2)O(2) production in HPAECs as assessed by flow cytometry. An electrophoretic mobility shift assay demonstrated that hyperoxia activated nuclear factor-kappaB (NF-kappaB) but not activator protein-1 (AP-1) and that MP attenuated hyperoxia-induced NF-kappaB activation dose dependently. With Western immunoblot analysis, IkappaB-alpha expression was decreased by hyperoxia and increased by MP treatment. These results suggest that MP downregulates hyperoxia-induced ICAM-1 expression by inhibiting NF-kappaB activation via increased IkappaB-alpha expression.

Detailed structural analysis on both human MRP5 and mouse mrp5 transcripts

The multidrug-resistant phenotype in tumor cells is attributed in part to anti-cancer drug efflux transporters such as the MRP family. The amino-terminal structure of MRP5 has not been refined. To determine the amino-terminal structure of a major transcript of the MRP5 gene, we performed primer extension analysis to determine a major transcriptional start site of this gene and compared the structure of human MRP5 and that of mouse mrp5. We successfully determined the structures of human MRP5 and mouse mrp5. Estimated amino acid sequences are 1437 and 1436 amino acids for human MRP5 and mouse mrp5 respectively, and were highly conserved (94.1%). We further showed that our previously identified SMRP mRNA was a splicing variant of the MRP5 gene, which was expressed in various human tissues, suggesting that a short form of MRP5 protein encoded by the SMRP mRNA may have a physiological role.

Molecular determinants of UCN-01-induced growth inhibition in human lung cancer cells

UCN-01 (7-hydroxystaurosporine) inhibits the growth of various malignant cell lines in vitro and in vivo. In this study, a human small cell lung carcinoma subline resistant to UCN-01, SBC-3/UCN, was established and characterized. SBC-3/UCN cells showed 8-fold greater resistance to the UCN-01-induced growth-inhibitory effect than the parent cells, SBC-3. No UCN-01-induced G1 accumulation in SBC-3 cells was observed in SBC-3/UCN cells and decreased expression of phosphorylated RB protein was found in SBC-3 cells. Neither basal expression nor induction of p21(Cip1) by UCN-01 treatment was detected in the SBC-3/UCN cell line. An inhibitory effect of UCN-01 on CDK2 activity, which is mediated by p21(Cip1)/CDK2 complex formation upon UCN-01 treatment, was observed in SBC-3 but not in SBC-3/UCN cells. SBC-3/UCN showed higher CDK6 activity than SBC-3 cells. UCN-01 did not inhibit the CDK4 and CDK6 activities in both cells. We screened the cell cycle regulatory molecules associated with G(1)/S progression and found a remarked decrease in interferon regulatory factor 1 (IRF-1), which is known to cooperate with p53 in p21(Cip1) induction. Our results suggest that p21(Cip1) regulation via the IRF-1-associated pathway may represent a major determinant of UCN-01-induced growth inhibition in human lung cancer cells.

Quantitative intensity measurement of equal thickness fringes in Si and MgO crystal images with an energy-filtering transmission electron microscope using an imaging plate

Quantitative measurement of intensity profiles of equal thickness fringes has been carried out in Si and MgO crystal images with an energy-filtering transmission electron microscope using an imaging plate. The crystals have a 90 degrees wedge-shape with [110] surfaces for Si and with [100] surfaces for MgO, and are observed under the exact axial incidence of a 200 keV electron beam along the [100] axis for Si and along the [110] axis for MgO. The intensities are measured in bright field and 022 and 040 dark field images for Si, and in bright field and 111, 002, 220, 113, 222, and 004 dark field images for MgO, with and without an energy slit having +/- 5 eV energy width for incident electrons. The intensity profiles obtained from the images are presented as standard experimental data for calculation of electron diffraction intensities. A few simulation programs for high-resolution transmission electron microscopy are checked by comparing the calculated diffraction intensities with the experimental data. The complex potential suitable for matching the data is discussed.

Hippocampal damage in the human brain after cardiac arrest

BACKGROUND AND PURPOSE

Very few reports are available on changes in the human hippocampus after cardiac arrest. The objective of this study was to investigate if specific hippocampal volume losses can be demonstrated in the human brain following reperfusion after cardiac arrest.

METHODS

We assessed the volumes of the hippocampal formation (HF) and temporal lobe excluding HF (TL) as the contrast using magnetic resonance (MR)-imaging-based volumetry in 11 vegetative patients after cardiac arrest and in 22 healthy controls of similar age, sex and body size distribution. The measured volumes were normalized for differences in the head size among subjects by dividing by the total intracranial volume (TICV). The MR images of the 11 patients were obtained between days 8 and 21 after cardiac arrest.

RESULTS

The observed volumes of HFs and TLs of both patient and control groups were as follows: right HF volume (HFV): 2.67 +/- 0.19 (mean +/- SD, cm(3)) in patients versus 3.89 +/- 0.44 in controls; left HFV: 2.72 +/- 0.17 versus 3.74 +/- 0.35; right TL volume (TLV): 73.37 +/- 6.54 versus 80.08 +/- 7.62, and left TLV: 72. 45 +/- 6.77 versus 78.59 +/- 6.68. The normalized indices (HFV/TICV and TLV/TICV) were as follows: right HF: 0.0021 +/- 0.0002 (mean +/- SD) in patients versus 0.0031 +/- 0.0001 in controls, p < 0.0001, left HF: 0.0022 +/- 0.0002 versus 0.0030 +/- 0.0001, p < 0.0001, right TL: 0.058 +/- 0.002 versus 0.064 +/- 0.004, p = 0.0007, and left TL: 0.058 +/- 0.002 versus 0.062 +/- 0.004, p = 0.0014. The HFV-TLV ratios (HFV/TICV divided by TLV/TICV) of both groups were: right HFV-TLV ratio: 0.037 +/- 0.004 in patients versus 0.049 +/- 0. 004 in controls, p < 0.0001, left HFV-TLV ratio: 0.038 +/- 0.004 versus 0.048 +/- 0.004, p < 0.0001.

CONCLUSIONS

The patient group had HFs that were 26.8-30.6% smaller than those of the control group, but in the patient group, the TLs slightly decreased in size by only 7.8-8.2% of the volume of those in the control group within 21 days after cardiac arrest. The volume reductions in the bilateral HFs of patients after cardiac arrest were significantly larger than those in the bilateral TLs. We speculate that this specific rapid hippocampal shrinkage reflects its greater vulnerability to global brain ischemia.

Chloroplast chaperonins: evidence for heterogeneous assembly of alpha and beta Cpn60 polypeptides into a chaperonin oligomer

Higher plant chloroplasts contain two chaperonin 60 family proteins, Cpn60alpha and Cpn60beta, which are known to have divergent amino acid sequences. Although Cpn60alpha and Cpn60beta are present in roughly equal amounts and copurify in their native states, a heterogeneous ensemble of the chaperonin oligomer has not yet been demonstrated. We separately purified Cpn60alpha and Cpn60beta proteins from spinach leaves as the monomeric form. Either antibody raised against one chaperonin 60 protein could coimmunoprecipitate the other chaperonin 60 protein in their oligomeric state but not in its monomeric state, suggesting that the chloroplast Cpn60alpha and Cpn60beta polypeptides actually reside in the same chaperonin oligomer in the stroma. Moreover, the chaperonin oligomers migrated as at least two distinct bands on the native gel electrophoresis, each of which contained both chaperonin 60 proteins. These results suggest that chloroplast chaperonin oligomers might be composed of at least two distinct sets of two chaperonin proteins.

Repair of segmental bone defects using bioactive bone cement: comparison with PMMA bone cement

We developed a bioactive bone cement (BABC) that consists of apatite and wollastonite containing glass ceramic (AW-GC) powder and bisphenol-A-glycidyl dimethacrylate (Bis-GMA) based resin. In the present study, the effectiveness of the BABC for repair of segmental bone defects under load-bearing conditions was examined using a rabbit tibia model. Polymethylmethacrylate (PMMA) bone cement was used as a control. A 15-mm length of bone was resected from the middle of the shaft of the tibia, and the tibia was fixed by two Kirschner wires. The defects were replaced by cement. Each cement was used in 12 rabbits; six rabbits were sacrificed at 12 and 25 weeks after surgery, and the tibia containing the bone cement was excised and tension tested. At both the intervals studied, the failure loads of the BABC were significantly higher than those of the PMMA cement. The BABC was in direct contact with bone, whereas soft tissue was observed between the cement and bone in all PMMA cement specimens. Results indicated that the BABC was useful as a bone substitute under load-bearing conditions.

[Unilaterally dominant chronic idiopathic interstitial pneumonia complicated by pulmonary thromboembolism]

A 51-year-old Japanese man was admitted to our hospital with the complaint of exertional dyspnea. A diagnosis of chronic idiopathic interstitial pneumonia (C-IIP) was made on the basis of findings of hypoxemia, restrictive ventilatory impairment, and interstitial shadows disclosed by chest roentgenograms. Chest computed tomographic (CT) scans clearly demonstrated left-side dominance of fibrotic changes. Dynamic CT and magnetic resonance angiography revealed the presence of thrombi in the left pulmonary artery. Lung scintigrams showed mismatching between ventilation and perfusion in the left lung. Pulmonary arteriography confirmed the diagnosis of left pulmonary thromboembolism (PTE). This was a rare case of PTE and C-IIP in which fibrotic changes occurred predominantly in the left lung field.

Promoter polymorphism of the beta2 bradykinin receptor gene is associated with essential hypertension

The present study examined the genetic contribution of the human beta2 bradykinin receptor gene in Japanese subjects with essential hypertension, and identified a -58T/C polymorphism of the core promoter that might be responsible for essential hypertension in Japanese. The study consisted of 100 hypertensive subjects and 100 age- and sex-matched controls. The allelic frequencies were 0.575 for the C allele and 0.425 for the T allele in hypertensive subjects, and 0.465 for the C allele and 0.535 for the T allele in normotensive subjects. The allelic frequencies were in Hardy-Weinberg equilibrium. Significant differences between hypertensive and normotensive subjects were seen in the genotypes distribution (p=0.049) and allelic frequencies (p=0.028), and the beta2 bradykinin receptor gene variant was associated with human essential hypertension in this Japanese population. This new marker may provide a valuable tool for assessing the risk for putative bradykinin-associated common diseases, such as hypertension, and cardiovascular diseases with genetic determinism. These results suggest that the -58 polymorphism of the human beta2 bradykinin receptor gene is an independent risk factor for essential hypertension in the Japanese population.

Effect of bioactive filler content on mechanical properties and osteoconductivity of bioactive bone cement

We took three types of bioactive bone cement (designated AWC, HAC, and TCPC), each with a different bioactive filler, and evaluated the influence of each filler on the mechanical properties and osteoconductivity of the cement. The cements consisted of bisphenol-a-glycidyl methacrylate-based (Bis-GMA based) monomers as an organic matrix, with a bioactive filler of apatite/wollastonite containing glass-ceramic (AW-GC) or sintered hydroxyapatite (HA) or beta-tricalcium phosphate (beta-TCP) powder. Each filler was mixed with the monomers in proportions of 50, 70, and 80% (w/w), giving a total of nine cement subgroups. The nine subgroups were designated AWC50, AWC70, AWC80, HAC50, HAC70, HAC80, TCPC50, TCPC70, and TCPC80. The compressive and bending strengths of AWC were found to be higher than those of HAC and TCPC for all bioactive filler contents. We also evaluated the cements in vivo by packing them into the intramedullary canals of rat tibiae. To compare the osteoconductivity of the cements, an affinity index was calculated for each cement; it equaled the length of bone in direct apposition to the cement, expressed as a percentage of the total length of the cement surface. Microradiographic examination up to 26 weeks after implantation revealed that AWC showed a higher affinity index than HAC and TCPC for each filler content although the affinity indices of all nine subgroups (especially the AWC and HAC subgroups) increased with time. New bone had formed along the AWC surface within 4 weeks, even in the cement containing AW-GC filler at only 50% (w/w); observation of the cement-bone interfaces using a scanning electron microscope showed that all the cements had directly contacted the bone. At 4 weeks the AWC had bonded to the bone via a 10 micron-thick reactive layer; the width of the layer, in which partly degraded AW-GC particles were seen, became slightly thicker with time. On the other hand, in the HAC- and TCPC-implanted tibiae, some particles on the cement surface were surrounded by new bone and partly absorbed or degraded. The results suggest that the stronger bonding between the inorganic filler and the organic matrix in the AWC cements gave them better mechanical properties. The results also indicate that the higher osteoconductivity of AWC was caused by the higher reactivity of the AW-GC powder on the cement surface.

Effect of a chimeric anti-ganglioside GM2 antibody on ganglioside GM2-expressing human solid tumors in vivo

Ganglioside GM2 is expressed on the surface of neuroblastoma and glioblastoma cells, and may also be detected on lung cancer cells. We reported previously that anti-ganglioside GM2 antibody exhibited strong in vitro anti-tumor activity against adriamycin-resistant cancer cells, which overexpressed ganglioside GM2. In the present study, we examined the in vivo anti-tumor effect of the chimeric anti-ganglioside GM2 antibody, KM966, against human lung and breast carcinoma cells, SBC-3 and MCF-7, and respective adriamycin-resistant clones, SBC-3/ADM and AdrR MCF-7 in BALB/c nu/nu mice. Ratios of tumor volume (T/C) between KM966-treated group and control group were 0.01 for SBC-3, 0.00 for SBC-3/ADM, 0.85 for MCF-7 and 0.34 for AdrR MCF-7 cells, respectively. Nude mice, which were pretreated with anti-asialo GM1 antibody to remove natural killer cells, were transplanted with 4 x 10(7) of SBC-3 and SBC-3/ADM subcutaneously. Seven days later, when tumors had grown to a diameter of over 8 mm, mice began to receive intravenous treatment of 120 microgram/mouse KM966 daily. Fourteen daily treatments induced regression to less than 4-mm diameter in 4/5 SBC-3 tumors and 5/5 of SBC-3/ADM tumors. All SBC-3/ADM tumors disappeared completely, suggesting that KM966 exerts a strong in vivo anti-tumor effect on ganglioside GM2-expressing cancer cells. In KM966-treated mice, the surface of the tumor cells stained positive with anti-human IgG. In addition, numerous leukocytes had infiltrated into the tumor mass. Antibody-dependent cell-mediated cytotoxicity (ADCC) of KM966 against tumor cells was examined in vitro by (51)Cr-release assay and revealed that KM966 induces ADCC activity against ganglioside GM2-expressing tumors. Our results suggest that immunotherapy using KM966 may be useful for the treatment of ganglioside GM2-expressing solid tumors.

Increased plasma levels of adrenomedullin in patients with systemic inflammatory response syndrome

We measured the plasma levels of adrenomedullin (AM), a novel vasodilating peptide, in 89 patients with various forms of systemic inflammatory response syndrome (SIRS) and 13 healthy volunteers serving as controls. Plasma levels of AM in SIRS (burns: 20.5 +/- 3. 2 fmol/ml [mean +/- SEM]; pancreatitis: 13.8 +/- 3.8 fmol/ml; trauma: 14.9 +/- 2.5 fmol/ml; traumatic shock: 41.1 +/- 7.8 fmol/ml; severe sepsis: 59.9 +/- 11.2 fmol/ml; septic shock: 193.5 +/- 30.1 fmol/ml) were significantly increased over those of controls (5.1 +/- 0.2 fmol/ml). The patients with traumatic shock or septic shock especially had higher levels of plasma AM than those with trauma or severe sepsis, respectively. These data showed that in patients with SIRS, plasma AM levels increased in proportion to the severity of illness. Subsequently, we measured the plasma levels of mediators such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8, plasminogen activator inhibitor (PAI)-1, and thrombomodulin (TM) in patients with traumatic shock and septic shock. A significant correlation was observed between plasma AM and TNF-alpha levels in patients with septic shock, suggesting an important role for AM as well as of TNF-alpha in the pathophysiology of inflammation. Plasma AM and IL-8 levels correlated positively with Acute Physiology and Chronic Health Evaluation (APACHE) II score, peak multiple organ failure (MOF) score during the first month and prognosis in patients with septic shock, as did plasma IL-6 levels in patients with traumatic shock. The plasma AM level might serve as a useful marker for evaluating the severity of disease and as an early predictor of subsequent organ failure and outcome in septic shock.

Nitric oxide differentially attenuates microvessel response to hypoxia and hypercapnia in injured lungs

The issue of whether the acinar microvessel response to alveolar hypoxia and hypercapnia is impaired in injured lungs has not been vigorously addressed, despite the importance of knowing whether it is or not when treating patients with serious lung injury in terms of permissive hypercapnia. Applying a real-time laser confocal luminescence microscope, we studied hypoxia- and hypercapnia-induced changes in the diameter of the intra-acinar arterioles, venules, and capillaries of isolated rat lungs harvested from animals exposed for 48 h to 21% O(2) (group N) or 90% O(2) (group H). Measurements were made with and without inhibition of nitric oxide (NO) synthase (NOS) by N(omega)-nitro-L-arginine methyl ester or of cyclooxygenase (COX) by indomethacin at different basal vascular tones evoked by thromboxane A(2) (TXA(2)) analog. Hypoxia in the absence of TXA(2) contracted arterioles in group N but not in group H. Attenuated hypoxia-induced arteriole constriction was restored almost fully by inhibiting NOS and partially by inhibiting COX. Hypercapnia induced venule dilation in group N, but did not dilate venules in group H, irrespective of TXA(2). NOS inhibition in hypercapnia unexpectedly enhanced venule and arteriole dilation in group H. These responses no longer occurred when NOS and COX were inhibited simultaneously. In conclusion, microvessel reactions to hypoxia and hypercapnia are abnormal in hyperoxia-injured acini, in which NO directly attenuates hypoxia-induced arteriole constriction, whereas COX inhibited by excessive NO impedes hypercapnia-induced microvessel dilation.

Cellular balance of glutathione levels through the expression of gamma-glutamylcysteine synthetase and glutathione thiol transferase genes in human hepatic cells resistant to a glutathione poison

Buthionine sulfoximine (BSO) is a synthetic amino acid that irreversibly inhibits glutathione biosynthesis and deranges reduced glutathione (GSH) metabolism in liver cells. We isolated two BSO-resistant lines, HLE/BSO2-1 and HLE/BSO2-2, from human hepatic HLE/WT cells. Cellular levels of the Pi class glutathione thiol transferase (GSTP1) were 3-fold lower in BSO-resistant lines than in HLE/WT cells. By contrast, gamma-glutamylcysteine synthetase (GCS) heavy subunit (GCSh) mRNA levels were markedly decreased in HLE/BSO2-1 and HLE/BSO2-2 as compared with HLE/WT. The expression of a dominant-negative mutant of c-Jun inhibited the GCSh promoter activity in HLE/WT, but not in HLE/BSO2-1. Cellular levels of AP-1, however, were not decreased in either BSO-resistant cell line. Transfection of GCSh promoter of various lengths driven reporter constructs showed no sequence-specific increase in the promoter activities in HLE/BSO2-1. However, transfection of GSTP1 cDNA into HLE/BSO2-1 and HLE/BSO2-2 restored the levels of GCSh mRNA and the GCSh promoter activity to those of HLE/WT. Sequences between -315 and -241 bp of the 5' region contained an AP-1 site responsible for the enhanced GCSh promoter activity in GSTP1 transfectants of HLE/BSO2-1. In vivo footprint analysis showed a specific protection of the AP-1 site on GCSh promoter in GSTP1 transfected HLE/BSO2-1. GSH homeostasis thus appears to be maintained by an interaction between GSTP1 and GCS in human hepatic cells resistant to the GSH poison.

[Decreased plasma soluble P-selectin level in coronary sinus after successful coronary angioplasty in patients with unstable angina]

P-selectin, an adhesion molecule, is involved in the alpha-granules of platelets with several factors such as platelet factor 4 (PF-4) and in Weibel-Parade bodies of endothelial cells with von Willebrand factor. The levels of the soluble form of P-selectin increase after angina episodes in patients with unstable angina, indicating that soluble P-selectin is associated with platelet activation and thrombogenesis in the coronary circulation. To evaluate the effect of successful coronary angioplasty on platelet activation or thrombogenesis in the coronary circulation, plasma soluble P-selectin, PF-4 and von Willebrand factor antigen levels were measured in blood obtained from the coronary sinus before and after successful coronary angioplasty in 15 patients with unstable angina. Fifteen patients with normal coronary angiograms served as controls. Plasma P-selectin, PF-4 and von Willebrand factor antigen levels were determined by sandwich enzyme-linked immunosorbent assays. Increased plasma soluble P-selectin (159.7 +/- 74.5 vs 78.7 +/- 26.4 ng/ml, p < 0.01) and PF-4 (456.5 +/- 87.0 vs 118.7 +/- 62.3 IU/ml, p < 0.01) levels were found in patients with unstable angina compared with those in controls, and were significantly decreased after angioplasty (147.8 +/- 69.6 ng/ml, p < 0.05; 401.6 +/- 108.5 IU/ml, p < 0.05), whereas von Willebrand factor antigen was unchanged. The ratio of plasma soluble P-selectin levels after and before angioplasty correlated with the corresponding ratio of plasma PF-4 levels (r = 0.53, p < 0.05), but not with the ratio of plasma von Willebrand factor antigen levels. The plasma levels of soluble P-selectin, which increase in the coronary circulation in patients with unstable angina, decrease after successful coronary angioplasty. Such data indicate that soluble P-selectin is associated with platelet activation and the therapeutical procedure improves the thrombogenic state in the coronary circulation.

In vitro interactions of a new derivative of spicamycin, KRN5500, and other anticancer drugs using a three-dimensional model

PURPOSE

KRN5500 is a new derivative of spicamycin produced by Streptomyces alanosinicus and is known to have a wide range of antitumor activities against human cancer cell lines. Because of its unique structure, this compound seems to have a different mode of action from other antitumor drugs and nonoverlapping toxicities. Therefore, KRN5500 is expected to be a suitable candidate for combination chemotherapy.

METHODS

We investigated the effects of combinations of KRN5500 and other anticancer drugs on the growth of a human non-small-cell lung cancer cell line, PC14, using a revised three-dimensional model.

RESULTS

Synergism was observed when KRN5500 and cisplatin were combined at concentrations in the ranges 0.005 to 0.25 microg/ml and 0.025 to 0.25 microg/ml, respectively. In combination with carboplatin, an analog of cisplatin, and etoposide, a marked synergistic interaction was also found.

CONCLUSION

These results suggest the usefulness of combinations of KRN5500 with cisplatin, carboplatin or etoposide for chemotherapy for non-small-cell lung cancer.

Cytoskeletons and antimitotic agents developed in Japan

Resistance to antimitotic agents is caused by decreased accumulation, altered tubulin, altered microtubule-associated proteins and increased metabolism. Vinca alkaloids, paclitaxel and docetaxel are actively effluxed by P-glycoprotein and/or the MRP1. Decreased intracellular accumulation is one of the major determinants of resistance to antimitotic agents. Increased tubulin levels and a decreased polymerization ratio were observed in resistant cells. Increased acetylation of tubulin and altered intracellular distribution of tubulin were also observed in resistant cells; however, the relationship between the function of tubulin and resistance remains unclear. The expression of each beta-tubulin isotype (beta 1-beta 6) is altered in resistant cells, but the functional differences among the isotypes have not been clarified. Recent evidence has demonstrated the alteration of binding properties of antimitotic agents in resistant cells. Therefore, the altered expressions of tubulin isotypes and related molecules might influence the antimitotic action and adverse events by antimitotic agents. Taxanes are metabolized and inactivated by p450 isozymes, and this is related to drug-resistant to taxanes.

Combination effects of TAS-103, a novel dual topoisomerase I and II inhibitor, with other anticancer agents on human small cell lung cancer cells

PURPOSE

TAS-103 [6-((2-(dimethylamino) ethyl)amino)-3-hydroxy-7H-iindeno(2,1-c)quinolin-7-one dihydrochloride] is a newly synthesized dual inhibitor of topoisomerase I and II. Since anticancer drugs are used in combination with other drugs for effective chemotherapy, we investigated the cytotoxic effect of TAS-103 in combination with other conventional anticancer agents, such as cisplatin, vindesine, doxorubicin, 5-fluorouracil, and the antitopoisomerase inhibitors SN-38 and etoposide in vitro.

METHODS

Inhibition of the growth of the human small-cell lung cancer cell line SBC-3 was evaluated using the tetrazolium dye (MTT) assay. Drug interactions were evaluated by isobologram analysis and the determination of combination indices supplemented by a three-dimensional model.

RESULTS

Simultaneous use of TAS-103 and cisplatin had a supraadditive effect, but combinations of TAS-103 with other drugs had an additive or marginally subadditive effect. Three-dimensional model analysis added more information about the synergistic concentration ranges of two drugs (cisplatin 200-400 nM and TAS-103 7 10 nM). Sequential use of TAS-103 and cisplatin had only an additive effect.

CONCLUSION

These results suggest that the concomitant use of TAS-103 and cisplatin has a greater cytotoxic effect on cancer cells than single drug use, and may provide a beneficial effect in the treatment of small-cell lung cancer.

Involvement of a chloroplast homologue of the signal recognition particle receptor protein, FtsY, in protein targeting to thylakoids

We isolated an Arabidopsis thaliana cDNA whose translated product shows sequence similarity to the FtsY, a bacterial homologue of SRP receptor protein. The Arabidopsis FtsY homologue contains a typical chloroplast transit peptide. The in vitro-synthesized 37 kDa FtsY homologue was imported into chloroplasts, and the processed 32 kDa polypeptide bound peripherally on the outer surface of thylakoids. Antibodies raised against the FtsY homologue also reacted with a thylakoid-bound 32 kDa protein. The antibodies inhibited the cpSRP-dependent insertion of the light-harvesting chlorophyll alb-binding protein into thylakoid membranes suggesting that the chloroplast FtsY homologue is involved in the cpSRP-dependent protein targeting to the thylakoid membranes.

Drug resistance in lung cancer

The major problem in lung cancer chemotherapy is the emergence of inherent and acquired drug resistance of the cancer cells. Establishment of drug-resistant sublines and comparative investigations of such cell lines with their parental cells to determine their molecular, biologic, and biochemical properties are important research strategies. Genetic changes in tumor cells may induce changes in their biochemical properties and chemosensitivity. Many mechanisms that render tumor cells resistant have been identified, and they have provided new molecular targets for surrogate markers to predict chemosensitivity. The new categories of anticancer drugs, such as topoisomerase I inhibitors and taxanes, and non-cytotoxic new drugs, have been introduced clinically. It is important to define the molecular determinants of resistance to these drugs. The development of an appropriate model for overcoming drug resistance is one of the important issues that should be solved before carrying out further clinical trials.

Mitogen-activated protein kinase antisense oligonucleotide inhibits the growth of human lung cancer cells

Mitogen-activated protein kinase (MAPK) pathway is proposed to be a therapeutic target for cancer cells. In order to find the potential therapeutic usefulness of MAPK for cancer cells, the effect of EAS1, an antisense oligonucleotide for an MAPK, on cancer-cell-growth were investigated in vitro. EAS1 effectively inhibited the growth of several human lung cancer cell lines such as PC-14 cells upon exposure to 10-0-10-1 microM of EAS1 determined dye-formation (MTT) assay. The ED50 values were comparable to those obtained for the inhibition of MAPK activity, DNA synthesis. EAS1 arrested the PC-14 cells at the G2/M phase of cell cycle followed by apoptosis in a dose-dependent manner. In order to determine the factors which influence the cellular sensitivity against MAPK inhibition, the effect of EAS1 on H-ras-transformed murine fibroblast cells were compared with that on parental cells. The NIH3T3 cells transformed by the H-ras gene (PT22-3) showed higher sensitivity against the effects of EAS1. Because MAPK activity was activated by H-ras gene transfection in PT22-3, the status of the MAPK cascade in cells was the determining factor for the efficacy of EAS1. In addition, cell permeabilization by digitonin enhanced the growth inhibitory effect of EAS1. Penetration of the cell membrane by EAS1 is also crucial for the growth inhibitory effect of EAS1. In conclusion, MAPK is an important target for cancer treatment and MAPK antisense oligonucleotide is a potentially significant antitumor oligonucleotide.

The serum interleukin 8 level reflects hepatic mitochondrial redox state in hyperthermochemohypoxic isolated liver perfusion with use of a venovenous bypass

BACKGROUND

We have recently developed a simple method of hyperthermochemohypoxic isolated liver perfusion (HILP) as a regional therapy for unrecognized liver micrometastases. However, little is known about the influence of HILP on cytokine production and liver function. We investigated the influence of HILP on interleukin 8 (IL-8) production and the hepatic mitochondrial function and assessed the relationship between these 2 parameters. We also measured the serum tumor necrosis factor-alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) levels to examine the involvement of HILP-induced cytokines in the tumor response.

METHODS

Sixteen patients with metastatic liver tumors were randomly assigned to undergo hepatectomy with HILP (group A, n = 9) or hepatectomy alone (group B, n = 7). The isolated liver was perfused for 30 minutes with Ringer's lactate solution containing chemotherapeutic agents warmed to 42 degrees C to 43 degrees C without oxygenation.

RESULTS

The serum IL-8 levels in group A were markedly increased, with peaks at 3 hours after reperfusion, which was significantly higher than levels in group B (P < .01). In group A the arterial ketone body ratio, which reflects the hepatic mitochondrial redox state, decreased during perfusion and was gradually restored to the preperfusion level 1 hour after reperfusion. However, in group B it decreased during hepatectomy but rapidly recovered 5 minutes after hepatectomy. There was a significant negative correlation between the peak serum IL-8 level and the initial velocity of arterial ketone body ratio recovery for the first 5 minutes after reperfusion r = -0.83, P < .001). The serum TNF-alpha and IL-1 beta were temporarily detected only in 3 of 9 patients in group A.

CONCLUSIONS

We have shown that HILP resulted in augmented IL-8 release but not TNF-alpha and IL-1 beta and that the serum IL-8 level reflects the hepatic mitochondrial redox state. These findings suggest that IL-8 production may be associated with hepatic mitochondrial impairment during ischemia. This work may contribute to new therapeutic strategies not only for hepatic ischemia reperfusion injury but also for metastatic liver tumors.