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Biomedical subjects

N Saijo

Publications and source records attributed to N Saijo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Radiation pneumonitis in lung cancer patients: a retrospective study of risk factors and the long-term prognosis.

PURPOSE: To retrospectively evaluate the risk factors for acute radiation pneumonitis (RP) and long-term prognosis of patients with lung cancer treated by thoracic radiotherapy. METHODS AND MATERIALS: Of the 256 lung cancer patients who underwent definitive thoracic radiotherapy between June 1988 and May 1998, the 191 patients who were capable of being evaluated were divided into three groups according to the grade of RP. RP was defined as "severe," when it caused severe clinical symptoms, such as intractable cough, dyspnea at rest, and the need for oxygen or steroid therapy. The definition was made by using a modification of the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer acute radiation morbidity scoring criteria. Factors that influenced the incidence of severe RP were assessed by using the Mantel-Haenszel chi(2) test in the univariate analysis and the logistic regression test in the multivariate analysis. Survival rates was calculated by using the Kaplan-Meier method, and the p values indicating the significance of differences between the RP groups were calculated by the log-rank test. RESULTS: Of the 94 patients (49%) who experienced clinical RP in this study, the RP was mild in 69 (36%) and severe in 25 (13%) patients. The 3-year survival rates of the patients who experienced no, mild, and severe RP were 33.4%, 38.2%, and and 0%, respectively, and the survival rate of the patients who experienced severe RP was significantly poorer than the other two groups combined (p = 0.0028). The incidence of severe RP did not correlate with any of the baseline patient characteristics, radiotherapeutic factors, or chemotherapeutic variables. Two clinical risk factors were identified from medical records before radiotherapy: low PaO2 (< 80 torr) and high C-reactive protein (CRP) (> 1.0 ng/mL). Both of them were significantly related to the development of severe RP in the univariate analysis (p = 0.004 and 0.013, respectively), and low PaO2 remained a significant risk factor in the multivariate analysis (p = 0.034). Multivariate analysis also revealed the occurrence of severe RP to be the most important factor determining poor survival (p = 0.0065). There was no significant difference in survival rate according to whether the patients had been treated with corticosteroids. CONCLUSION: Mild and severe RP occurred in 69 (36%) and 25 (13%), respectively, of 191 lung cancer patients who had undergone irradiation of the chest. Only severe RP was an adverse prognostic factor. Low PaO2 (< 80 torr) before radiotherapy was a significant risk factor predictive of severe RP. The role of corticosteroids in RP could not be accurately determined.

Aged↗
PubMed2001

A phase II study of paclitaxel plus cisplatin for advanced non-small-cell lung cancer in Japanese patients.

We performed a clinical phase II trial of the combination of paclitaxel and cisplatin in patients with locally advanced (stage IIIB) or metastatic non-small-cell lung cancer (NSCLC) using a 3-h infusion of paclitaxel followed by a 1 to 2-h infusion of cisplatin, with a short premedication regimen. Treatment was repeated every 21 days for at least two cycles. The patients received paclitaxel 180 mg/m2 followed by cisplatin 80 mg/m2. Enrolled in the trial were 33 chemotherapy-naive patients with stage IIIB (15%) or stage IV (85%) NSCLC. Their median age was 61 years (range 43-71 years). Of the 33 patients, 10 (30%) were women and 23 (70%) were men, and 82% had adenocarcinoma. With 78 courses of chemotherapy administered, 32 patients were evaluable for toxicity and response. Hematologic toxicities were moderate: Japan Clinical Oncology Group (JCOG) grade 3 or 4 neutropenia occurred in 37% of the cycles (53% of patients). Other toxicities consisted mainly of grade 1 or 2 alopecia and nausea/vomiting, but also included grade 1 or 2 neuropathy (47%), hypotension (grade 1 in 6%, grade 3 in 3%) and allergic reactions (grade 1 or 2 in 16%, grade 3 in 3%). Of 32 patients evaluable for response, a partial response was achieved in 10 (31%; 95% confidence interval 16% to 50%), stable disease was seen in 16 (50%), and disease progression was seen in 2 (6%). The median survival time was 14.8 months and the 1-year survival rate was 56%. These results suggest that the combination of paclitaxel and cisplatin is a well-tolerated and active regimen in Japanese patients with advanced NSCLC. In view of the promising survival outcomes, further evaluation in prospective randomized trials with other regimens is warranted.

Adult↗
PubMed2001

Double-blind randomized control trial of the effect of recombinant human erythropoietin on chemotherapy-induced anemia in patients with non-small cell lung cancer.

BACKGROUND: We studied the clinical effect of recombinant human erythropoietin (r-huEPO) on anemia induced by two courses of cisplatin-based chemotherapy in patients with non-small cell lung cancer (NSCLC). METHODS: Seventy-two patients with NSCLC were randomized into three groups, receiving 100, or 200 IU/kg of r-huEPO, or placebo. The r-huEPO and placebo were administered subcutaneously three times a week for 6 weeks, starting 2 weeks after the initiation of chemotherapy. RESULTS: In the 53 evaluable patients, hemoglobin (Hb) levels at the nadir after the second cycle of chemotherapy were significantly elevated compared with the nadir after the first cycle in both r-huEPO treated groups, while this level was decreased in the placebo group. Hb levels at the end of the second course of chemotherapy (week 8) in both r-huEPO groups were higher than that in the placebo groups. No adverse drug reaction attributable to r-huEPO was observed. Serum erythropoietin levels after the administration of r-huEPO were higher than those after placebo administration. CONCLUSIONS: r-huEPO had an effect in preventing anemia in patients with NSCLC who had cisplatin-based chemotherapy.

Anemia↗
PubMed2001

Topoisomerase I targeting agents in small-cell lung cancer.

The topoisomerase I inhibitors such as irinotecan and topotecan are active agents against small-cell lung cancer that are effective in treating not only chemotherapy-naïve tumors but also progressed-stage tumors after treatment with cisplatin-based regimens, because their mechanism of antitumor activity differs from that of the agents included in standard chemotherapy for small-cell lung cancer. Etoposide plus cisplatin or etoposide plus cisplatin alternating with cyclophosphamide, doxorubicin, and vincristine is considered the standard regimen for small-cell lung cancer. No new standard combination chemotherapy for small-cell lung cancer has been developed over the past decade. Irinotecan with cisplatin is now established as a new standard chemotherapy for extensive-stage small-cell lung cancer based on the results of the Japan Clinical Oncology Group trial. Of course, confirmation through phase III studies will be extremely important. The Japan Clinical Oncology Group is intensively investigating other irinotecan-containing regimens and the incorporation of irinotecan into treatment of patients with limited-stage small-cell lung cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Mechanism of the radiosensitization induced by vinorelbine in human non-small cell lung cancer cells.

Vinorelbine (Navelbine, KW-2307), a semisynthetic vinca alkaloid, is a potent inhibitor of mitotic microtubule polymerization. The aims of this study were to demonstrate radiosensitization produced by vinorelbine in human non-small cell lung cancer (NSCLC) PC-9 cells and to elucidate the cellular mechanism of radiosensitization. A clonogenic assay demonstrated that PC-9 cells were sensitized to radiation by vinorelbine with a maximal sensitizer enhancement ratio at a 10% cell survival level of 1.35 after 24-h exposure to vinorelbine at 20 nM. After 24-h exposure to vinorelbine at 20 nM, the approximately 67% of the cells that had accumulated in the G2/M-phase were cultured in the absence of vinorelbine and then irradiated at a dose of 8 Gy. Flow cytometric analyses showed prolonged G2/M accumulation concomitant with continuous polyploidization, and induction of apoptosis was observed in the cells subjected to the combination of vinorelbine-pretreatment and radiation. Polyploidization and induction of apoptosis were confirmed by morphological examination and a DNA fragmentation assay, respectively. We concluded that vinorelbine at a minimally toxic concentration moderately sensitizes human NSCLC cells to radiation by causing accumulation of cells in the G2/M-phase of the cell cycle. Prolonged G2/M accumulation concomitant with continuous polyploidization and increased susceptibility to induction of apoptosis may be associated with the cellular mechanism of radiosensitization produced by vinorelbine.

Carcinoma, Non-Small-Cell Lung↗
PubMed2001

Gene expression profiling of exposure to TZT-1027, a novel microtubule-interfering agent, in non-small cell lung cancer PC-14 cells and astrocytes.

Clinical use of TZT-1027, a microtubule-interfering agent that inhibits the polymerization of tubulin, is expected because of its potent effects on solid tumors. TZT-1027 is thought to act directly on cellular microtubules, and arrest cell mitosis, however, the molecular mechanisms of the microtubule damage by TZT-1027 have not been fully identified. To investigate the possible novel mechanisms of action of TZT-1027, we used the cDNA macroarray technique to examine its effect on the expression of hundreds of tightly transcriptionally controlled genes. We used two cell lines, one was human non-small cell lung carcinoma PC-14 cells as a model for cancer cells, and the other was human astrocytes as a model for normal neuronal cells, because the dose-limiting-factor of microtubule-interfering agents is mainly peripheral neurotoxicity. mRNAs prepared from the PC-14 and astrocyte cell lines treated with TZT-1027 were compared with 588 genes spotted onto the filter, and which gene groups TZT-1027 modulated between the two cell lines was investigated. TZT-1027 exposure modulated expression of a variety of genes including the genes encoding cell-cycle and growth regulators, receptors, angiogenesis and invasion regulators, rho family small GTPases and their regulators and growth factors and cytokines. However, the way of gene regulation by TZT-1027 exposure was different between PC-14 cells and astrocytes. Genes up-regulated in both PC-14 cells and astrocytes were those for RAR-epsilon, TNFR 1 and 2 and so on. Specifically altered genes in PC-14 cells, such as the genes coding for cytokeratin 8, XPG, fau and the genes regulated only in PC-14 cells may be involved in the antitumor activity of TZT-1027. On the other hand, growth factor receptor precursors was upregulated specifically in astrocytes by TZT-1027 and this gene regulation only in astrocytes may be candidates related with neurotoxicity.

Antineoplastic Agents↗
PubMed2001

Mechanisms of action of the novel sulfonamide anticancer agent E7070 on cell cycle progression in human non-small cell lung cancer cells.

E7070 is a novel sulfonamide antitumor agent that exhibits potent antitumor activity in vitro and in vivo. This compound affects cell cycle progression in human tumor cells. To elucidate the mechanisms by which E7070 inhibits tumor cell growth, we established and characterized an E7070-resistant subline, A549/ER, from a human non-small cell lung cancer cell line A549. Flow cytometric analyses demonstrated an increase in G0/G1 and a decrease in S phase populations in cells treated with E7070 at 20 or 100 microg/ml for 24 h. Longer exposure to E7070, i.e. 48 and 72 h, increased the G2/M phase fraction in A549 cells. These inhibitory actions of E7070 on cell cycle progression were not observed in A549/ER cells. E7070 inhibited the phosphorylation of pRb, decreased expressions of cyclin A, B1, CDK2, and CDC2 proteins, and suppressed CDK2 catalytic activity with the induction of p53 and p21 proteins in A549 cells but not in A549/ER cells. Taken together, these results suggest that E7070 exerts its antitumor effects by disturbing the cell cycle at multiple points, including both the G1/S and the G2/M transition, in human lung cancer cells.

Antineoplastic Agents↗
PubMed2001

Polymorphisms of metabolizing enzymes and transporter proteins involved in the clearance of anticancer agents.

BACKGROUND: The efficacies and toxicities of anticancer agents vary greatly among patients. This is attributable to the activities of drug-metabolizing enzymes and membrane transporters, primarily determined by polymorphisms of the functions of genes encoding these proteins. DESIGN: We reviewed the available literature on drug-metabolizing enzymes and membrane transporters, especially their physiological functions, genetic and functional polymorphisms, and involvement in metabolism, pharmacokinetics and toxicity of anticancer agents. RESULTS: Nine enzymes metabolizing anticancer agents have been shown to have genetic polymorphisms: dihydropyrimidine dehydrogenase, cytochrome P450, NAD(P)H:quinone oxidoreductase 1, N-acetyltransferase 2, thiopurine methyltransferase, glutathione S-transferase, and uridine diphosphate glucuronosyltransferase. Decreased activities of these proteins can cause not only inherited metabolic disorders, but also extraordinarily severe toxicity in cancer patients given chemothearpy. Transporter proteins mediate cellular uptake and secretion of organic anions and cations. These proteins have recently been shown to play critical roles in the clearance of anticancer agents, although relations between patients' genetics backgrounds and the clinical significance of drug actions are poorly understood. CONCLUSIONS: Further studies should be focused on dosing and selection of anticancer agents, based on the type and extent of metabolic variation among individuals, in order to avoid adverse reactions and therapeutic failure.

Antineoplastic Agents↗
PubMed2001

Phase I studies of cisplatin and docetaxel administered by three consecutive weekly infusions for advanced non-small cell lung cancer in elderly and non-elderly patients.

BACKGROUND: To determine the maximum tolerated dose and recommended dose of cisplatin and docetaxel administered by three consecutive weekly infusions in both non-elderly (< or =74 years) and elderly (> or =75 years) patients, we conducted two independent phase I studies for nonelderly and elderly patients with non-small cell lung cancer. METHODS: Between April 1998 and September 1999, 26 non-elderly (median, 54 years; range, 44-73 years) and 12 elderly (median, 76 years; range, 75-80 years) patients with non-small cell lung cancer were entered in these studies. The eligibility criteria of both cohorts were identical except for age. Chemotherapy consisted of cisplatin 25 mg/m2 and an escalated dose of docetaxel on days 1, 8 and 15 every 4 weeks. The initial dose of docetaxel was 20 mg/m2 and it was increased by 5 mg/m2 at each dose level. RESULTS: In the non-elderly and elderly cohorts, up to 45 or 25 mg/m2 of docetaxel, respectively, were administered. Dose-limiting toxicities were neutropenia, liver damage, pneumonia and omission of treatment on day 15 by leukopenia and refusal in the non-elderly cohort; pneumonia and omission of treatment on day 15 by refusal due to fatigue/asthenia or fever in the elderly cohort. We considered the recommended doses for phase II studies were cisplatin 25 mg/m2 and docetaxel 35 mg/m2 on days 1, 8 and 15 for non-elderly patients and cisplatin 25 mg/m2 and docetaxel 20 mg/m2 on days 1, 8 and 15 for elderly patients. Seven of 26 (27%) and seven of 12 (58%) patients achieved a partial response, median survival times were 8.7 and 7.2 months and 1 year survival rates were 27 and 27% in the non-elderly and elderly cohorts, respectively. CONCLUSIONS: Further evaluation of this combination chemotherapy is warranted for both nonelderly and elderly patients with non-small cell lung cancer but the dose of docetaxel should be lower for elderly than non-elderly patients.

Adult↗
PubMed2001

Phase I and pharmacological study of paclitaxel given over 3 h with cisplatin for advanced non-small cell lung cancer.

BACKGROUND: To establish the toxicities and maximum tolerated dose of paclitaxel given over 3 h in combination with cisplatin, to determine the pharmacokinetic profiles of these two drugs and to observe their antitumor activity, we conducted a combination phase I study in non-small cell lung cancer. METHODS: Patients received paclitaxel doses of 150-210 mg/m2 given over 3 h and cisplatin doses of 60-80 mg/m2 as a 1 h infusion 2 h after the end of the paclitaxel infusion. RESULTS: A total of 25 patients with previously untreated non-small cell lung cancer were enrolled. Granulocytopenia was the most frequent hematological toxicity and the most prominent non-hematological toxicity was sensory dominant neuropathy. Two of six patients experienced dose limiting toxicities (leukopenia, infection and neuropathy) at a dose of paclitaxel 210 mg/m2 and cisplatin 60 mg/m2, which was considered the maximum tolerated dose. There were seven partial responses among 24 evaluable patients, for an overall response rate of 29%. The median survival time was 341 days and the 1 year survival rate was 45.8%. As the paclitaxel pharmacokinetic parameters in this study were consistent with those of our previous single agent study, we found no significant drug-drug interaction between the 3 h infusion paclitaxel and cisplatin. CONCLUSION: The recommended doses for further study are determined to be paclitaxel 180 mg/m2 and cisplatin 80 mg/m2. This is a well-tolerated and active regimen for non-small cell lung cancer. In view of the promising survival outcome, further evaluation in prospective randomized trials versus other regimens is warranted.

Adult↗
PubMed2001

Recent advances in the chemotherapy of non-small cell lung cancer.

Chemotherapeutic regimens containing new anticancer agents in combination with cisplatin and carboplatin have been demonstrated to be equivalently active against advanced non-small cell lung cancer. The choice of a chemotherapeutic regimen depends on differences in time to progression, response rate, toxicity profile, cost and symptom relief. Several other strategies, such as three-drug combinations, sequential use of a third drug, weekly administration, etc., have been evaluated to improve the chemotherapeutic effect. The sequencing of the human genome may permit targeting of specific abnormalities related to each lung cancer with target-based drugs. This should increase the possibility of application of individualized therapy and, we would hope, improve survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Randomized phase I study of standard-fractionated or accelerated-hyperfractionated radiotherapy with concurrent cisplatin and vindesine for unresectable non-small cell lung cancer: a report of Japan Clinical Oncology Group Study (JCOG 9601).

BACKGROUND: We attempted dose escalation of standard-fractionated and accelerated-hyperfractionated radiotherapy combined with concurrent cisplatin and vindesine to improve local control and survival in unresectable non-small cell lung cancer. METHODS: Twenty-one patients were enrolled between June 1996 and August 1997. There were 19 males and two females and their median age was 65 years (range 45-74 years). Performance status was 0 in 10 cases and 1 in 11 cases. Disease stage was IIIA in three cases and IIIB in 18 cases. The cases were randomized to a standard-fractionated arm (n = 10) or an accelerated-hyperfractionated radiotherapy arm (n = 11) with two or three cycles of concomitant cisplatin 80 mg/m(2) on day 1 and vindesine 3 mg/m(2) on days 1 and 8 every 4 weeks in both arms. Dose escalation from 60 Gy/30 fractions/6 weeks to 70 Gy/35 fractions/7 weeks was planned in the standard-fractionated radiotherapy group and from 54 Gy/36 fractions/3.6 weeks to 60 Gy/40 fractions/4 weeks and then 66 Gy/44 fractions/4.4 weeks in the accelerated-hyperfractionated radiotherapy group. RESULTS: Grade 3 or 4 hematological toxicities were observed as follows: in the standard-fractionated/accelerated-hyperfractionated radiotherapy group, leukocytopenia 9/10, anemia 2/3 and thrombocytopenia 0/2. Grade 3 non-hematological toxicity consisted of esophagitis 0/3, increased serum total bilirubin 2/0 and hypoxia 0/1. Two patients died of radiation pneumonitis in the standard-fractionated radiotherapy group. Dose-limiting toxicity was observed in four of the 10 and seven of the 11 patients at initial dose level of standard-fractionated radiotherapy, 60 Gy/30 fractions/6 weeks, and of accelerated-hyperfractionated radiotherapy, 54 Gy/36 fractions/3.6 weeks, respectively. Thus, we failed to escalate the dose of radiotherapy in both arms. The overall response rate in the standard-fractionated group and the accelerated-hyperfractionated radiotherapy group was 70 and 73% and the 1-year survival rate was 70 and 64%, respectively. CONCLUSIONS: We concluded that these schedules of radiotherapy with concurrent cisplatin and vindesine were unacceptable for use in patients with unresectable non-small cell lung cancer. Further modifications of the schedule for radiotherapy and evaluation of combination with new chemotherapy are warranted.

Aged↗
PubMed2001

A dose escalation study of paclitaxel and carboplatin in untreated Japanese patients with advanced non-small cell lung cancer.

BACKGROUND: The combination of paclitaxel (225 mg/m(2), 3-h infusion) and carboplatin (area under the curve 6) is widely used for non-small cell lung cancer in the USA. In Japan, however, the recommended dose for single-use paclitaxel in 3-h infusion is 210 mg/m(2) and the optimal dose of this agent in combination with carboplatin has not been established. This dose escalation study was designed to determine the maximum tolerated dose of paclitaxel in 3-h infusion plus carboplatin at a fixed dose of area under the curve 6 for Japanese patients with advanced, untreated non-small cell lung cancer. METHODS: Between October 1999 and May 2000, 19 patients were enrolled and 18 of these patients were evaluable for toxicity. Chemotherapy consisted of carboplatin area under the curve 6 and an escalated dose of paclitaxel on day 1 every 3-4 weeks. The initial dose of paclitaxel was 175 mg/m(2) and was increased by 25 mg/m(2) at each dose level. RESULTS: Neutropenia was the major toxicity observed, but was not dose related. Febrile neutropenia was not observed. No grade 3 or more peripheral neuropathy, myalgia or arthralgia was reported. The maximum tolerated dose was not determined even at the highest paclitaxel dose level (225 mg/m(2)) in this study. Partial responses were observed in six of the 19 patients (31.6%). CONCLUSION: We conclude that paclitaxel at 225 mg/m(2) in 3-h infusion and carboplatin area under the curve 6 can safely be given to Japanese patients with non-small cell lung cancer.

Adult↗
PubMed2001

A phase I/II study of cisplatin and vinorelbine chemotherapy in patients with advanced non-small cell lung cancer.

BACKGROUND: A combination of cisplatin and vinorelbine chemotherapy is effective in cases of advanced non-small cell lung cancer, but the optimum administration schedule for both drugs has not yet been defined. The aim of this study was to determine the maximum dose of vinorelbine that can be tolerated while receiving a fixed dose of cisplatin every 3 weeks and to observe the response in Japanese patients with advanced non-small cell lung cancer who had not previously received chemotherapy. METHODS: Cisplatin was given at a dose of 80 mg/m2 on day 1. Vinorelbine was administered on days 1 and 8 at a starting dose of 25 mg/m2 that was then increased by 5 mg/m2 increments. This treatment was repeated every 3 weeks. RESULTS: Twenty-one patients received a total of 54 chemotherapy cycles consisting of three different vinorelbine dosages. Toxicity and efficacy were evaluated in all of the patients. The main dose-limiting toxicity was neutropenia. Grades 3-4 leukopenia and neutropenia were observed in 57% and 86% of all cycles, respectively. These conditions were reversible and did not result in death from toxicity. The most severe non-hematological toxicity symptom was a grade 3 infection and reaction at the site of injection. The maximum tolerated dose of vinorelbine was 35 mg/m2. The objective response was noted in one of six patients at dose level 1, in four of 12 patients at dose level 2 and in two of three patients at dose level 3. CONCLUSION: The recommended doses were 80 mg/m2 for cisplatin and 30 mg/m2 for vinorelbine. The combination of cisplatin and vinorelbine repeated every 3 weeks is well tolerated and has shown promising anti-tumor activity against non-small cell lung cancer.

Adult↗
PubMed2001

CPT-11 alters the circadian rhythm of dihydropyrimidine dehydrogenase mRNA in mouse liver.

Combination chemotherapy consisting of 5-fluorouracil (5-FU) and 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carboxycamptothecin (CPT-11) is a promising regimen for gastrointestinal cancer. The circadian-dependent efficacy and toxicity of 5-FU are related to the circadian variation in the activity of dihydropyrimidine dehydrogenase (DPD), which is a rate-limiting enzyme in the pyrimidine catabolic pathway. To optimize the schedule of the CPT-11 plus 5-FU combination, we investigated the effect of CPT-11 on the circadian rhythm of DPD in vivo. In control mice, the DPD mRNA level in the liver was significantly higher at 14:00 than that at 02:00. After intravenous administration of CPT-11 (30 mg / kg) at 20:00, the circadian rhythm of the DPD mRNA level in the liver was no longer observed 18 h later (14:00), but it was unaffected 6 and 18 h later (at 14:00 and 02:00) when CPT-11 was given at 08:00. In addition, a dose-dependent lengthening of the period of the circadian rhythm of DPD was observed for 42 h after intravenous injection of CPT-11 at 20:00. The levels of DPD protein and activity at 21 h after administration of CPT-11 (at 17:00) were significantly higher than at 9 h (at 05:00). These results suggest that CPT-11 may influence the circadian rhythm of DPD at the transcriptional level. Modulation of the circadian rhythm of DPD by CPT-11 may be a factor in optimizing the combination of 5-FU and CPT-11.

Animals↗
PubMed2001

Reversal of cisplatin resistance by the 1,4-benzothiazepine derivative, JTV-519.

The 1,4-benzothiazepine derivative JTV-519 is a new type of calcium ion channel modulator. We examined the modulatory effect of JTV-519 on the antitumor activity of several platinum compounds (cisplatin, carboplatin, and nedaplatin) in a human cancer cell line resistant to cisplatin (PC-14 / CDDP) in vitro. PC-14 / CDDP cells showed 8-fold resistance to cisplatin compared with the parental PC-14 cells as determined by dye formation [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT] assay. In PC-14 / CDDP, but not PC-14 cells, augmentation of cytotoxicity was observed when a nontoxic concentration (10 mM) of JTV-519 was combined with the platinum compounds. Increased intracellular cisplatin accumulation was observed in PC-14 / CDDP cells in the presence of JTV-519 as measured by atomic absorption assay. Therefore, increased cisplatin accumulation was considered to be a possible mechanism underlying the reversing effect of JTV-519 on cisplatin resistance. These results suggest that JTV-519 is a potent agent reversing cisplatin resistance.

Antineoplastic Agents↗
PubMed2001

Enhancement of in vivo antitumor activity of a novel antimitotic 1-phenylpropenone derivative, AM-132, by tumor necrosis factor-alpha or interleukin-6.

TK5048 and its derivatives, AM-132, AM-138, and AM-97, are recently developed antimitotic (AM) compounds. These 1-phenylpropenone derivatives induce cell cycle arrest at the G2 / M phase of the cell cycle. TK5048 inhibited tubulin polymerization in human lung cancer PC-14 cells in a concentration-dependent manner. In a polymerization assay using bovine brain tubulin, AM-132 and AM-138 were quite strong, AM-97 was moderately strong, and TK5048 was a relatively weak inhibitor of tubulin polymerization. A murine leukemia cell line resistant to a sulfonamide antimitotic agent, E7010, which binds to colchicine-binding sites on tubulin, was cross-resistant to the in vitro growth-inhibitory effect of AM compounds. Inhibition of tubulin polymerization is therefore one of the mechanisms of action of these AM compounds against tumor cells. To profile the antitumor effect of AM compounds, the in vivo antitumor effect of AM-132 was evaluated against cytokine-secreting Lewis lung carcinoma (LLC). Tumor-bearing mice were treated with intravenous AM-132 using three different treatment schedules. LLC tumors expressing tumor necrosis factor-alpha (TNF-alpha), granulocyte macrophage colony-stimulating factor (GM-CSF), or interleukin (IL)-6 were very sensitive to AM-132. In particular, LLC tumors expressing IL-6 were markedly reduced by AM-132 treatment, and showed coloring of the tumor surface and unusual hemorrhagic necrosis. These results suggest a combined effect of AM-132 and cytokines on the blood supply to tumors.

Animals↗