A new dosage formulation (ACR-CH), composed of aclarubicin (ACR) bound to fine activated carbon particles, has been developed for the treatment of lymph node metastases in breast cancer. ACR-CH is designed to (a) adsorb a great amount of aclarubicin and desorb in a free state; (b) distribute a greater amount of ACR for a longer period of time selectively to the regional lymph nodes; (c) be decreased in the systemic toxicity; and (d) enhance its therapeutic effect on lymph node metastases. In this clinical trial in 20 patients with breast cancer, ACR-CH was injected intra- and peritumorally just before operation for breast cancer, and we examined the extent of blackened nodes produced by ACR-CH. ACR-CH blackened about 70% of the axillary lymph nodes with cancer metastasis as well as the nodes without metastasis. In conclusion, ACR-CH will be useful for dissection of lymph nodes by visualizing the nodes during operation for breast cancer.

We investigated the delivery of adriamycin (ADR) to the regional lymph nodes of the stomach following the gastric submucosal injection of liposomal adriamycin (Lipo-ADR) in 34 gastric carcinoma patients, as well as following intravenous administration of free ADR (F-ADR) in 18 patients, then followed these patients for a minimum of 5 years or until death. Prior to radical gastrectomy. Lipo-ADR was endoscopically injected into the gastric submucosa adjacent to the primary tumor via a needle-tipped catheter. After Lipo-ADR injection, the ADR concentration in the primary and secondary drainage lymph nodes was higher than in the other regional lymph nodes. Thus, the regional nodes more susceptible to the involvement of metastasis showed higher levels of ADR. In contrast, the intravenous administration of F-ADR produced a similar and far lower ADR concentration in all the nodes. Delivery of ADR to the primary drainage lymph nodes following injection of 5 mg of Lipo-ADR (n = 19) was compared with delivery to the left gastric artery lymph nodes after intravenous administration of an equal dose of Lipo-ADR. The ADR levels (microgram/g) after gastric submucosal injection were 15.1 +/- 8.30 on day 1 (n = 4) and 11.9 +/- 4.80 on day 4 (n = 6), whereas, the ADR levels after intravenous administration were 0.29 +/- 0.10 on day 1 (n = 4) and 0.36 +/- 0.0 on day 4 (n = 2). The differences between the two groups were significant (p < 0.05). The ADR levels after the gastric submucosal injection were far higher than those after intravenous administration. These findings indicate that the gastric submucosal injection of Lipo-ADR can specifically deliver ADR to the regional lymph nodes at high concentrations. Disease-free survival of the stage III a-b patients (n = 7) with this regional lymph nodes-targeted chemotherapy was 71.4% in 5 years, while that with intravenous F-ADR administration (n = 5) was 60.0%. This preoperative adjuvant chemotherapy targeting the regional lymph nodes may be effective in preventing the recurrence of gastric carcinoma.

Anti-tumor quinone, including mitomycin C (MMC), needs to be activated by bioreduction to exert its cytotoxic activities. The enzymes underlying this bioreductive activation have been the subject of extensive research on Mitomycin C. Cytochrome P450 reductase, cytochrome b5 reductase, xanthine oxidase, xanthine dehydrogenase and DT-diaphorase (DTD) have been shown to be involved in the reduction of MMC. The relationship between bioreductive enzymes and the cytotoxicity of quinone, however, has not been analyzed yet. In this study, we investigated the relationship between the bioreductive enzymes and the cytotoxicity of MMC. We carried out the following experiments and the following results were obtained. I) We isolated an MMC-resistant variant. This cell showed five-fold resistance to MMC as compared with the parental cell line. DTD was deficient in this resistant cell. II) We have examined the bioreductive enzyme activities of DTD and cytochrome P450 reductase and IC50's of MMC in 13 colon and gastric carcinoma cell lines. A positive correlation was not found between the enzyme activities and MMC sensitivities, but the cells with little or no DTD activity showed higher IC50 values compared to the other cell lines. III) To elucidate directly the role of DTD in MMC sensitivity, we introduced NQO1 gene into St-4 cells. NQO1 gene encodes DTD and St-4 cells have no DTD activity. All of the transfectants showed five- to ten-fold higher sensitivity to MMC as compared to the parental St-4 cells. The above data indicate that DTD is a critical determinant of sensitivity to MMC in aerobic conditions.

The nucleoside kinases phosphorylate nucleosides to corresponding nucleoside 5'-monophosphates. Their activities are essential for activation of chemotherapeutically important nucleoside analogues. Since, among them, deoxycytidine kinase has high activity in a wide variety of tumor tissues, a relatively low substrate specificity, and is not cell-cycle regulated, 2'-substituted-2'-deoxycytidine analogues should be suitable for antitumor antimetabolites. Gemcitabine, DMDC, and CNDAC have been developed for such analogues. These nucleosides showed potent antitumor activity against various solid tumors. They inhibited mainly DNA synthesis of tumor cells and, to some extent, inhibited RNA synthesis. To inhibit RNA synthesis of tumor cells would be important to kill solid tumor cells, which are heterogenous. ECyd was designed as an inhibitor of both DNA and RNA syntheses and showed potent antitumor activity against a variety of human tumor cells in xenografts.

Angiogenesis is controlled by a local balance between stimulators and inhibitors of growth of new vessels. Aberrant angiogenesis is closely involved in invasion/metastasis as well as malignant tumors. There are several strategies for inhibiting tumor angiogenesis. In this article, we investigator whether endogenous angiogenesis inhibitors, plasminogen activator and matrix metalloprotease inhibitors and Flk-1 antagonists could be anti-angiogenesis targets of intrinsic interest.

KRN 5500 is a new semi-synthetic antitumor compound derived from spicamycin and has a unique structure. The compound showed a broad spectrum of antitumor activity against human colon, stomach, esophageal, breast and lung cancer xenografts in nude mice. Therapeutic efficacy of KRN 5500 against liver metastasis of COL-1 human colon cancer scid mice was examined. The treatment with KRN 5500 inhibited tumor growth in the liver and reduced the serum TPA concentration to a normal level. KRN 5500 inhibits protein synthesis in rabbit reticulocyte lysates. Among several metabolites of KRN 5500, only SAN-Gly showed a potent inhibitory activity against protein synthesis in reticulocyte lysates. TLC analysis of KRN 5500 metabolites using 7 human colon cancer cell lines and 3 normal cell lines demonstrated a correlation between the cytotoxicity of KRN 5500 and converting activity from KRN 5500 to SAN-Gly. These results indicate that SAN-Gly is the intracellular active metabolite and that converting activity from KRN 5500 to SAN-Gly is the major determinant of KRN 5500 cytotoxicity.

Azatyrosine is known to convert ras, raf or c-erbB-2-transformed NIH3T3 cells to a normal phenotype. We attempted to identify the signal-transduction process triggered by oncogenic c-ErbB-2 that was inhibited by azatyrosine. Azatyrosine did not suppress activation of Ras induced by introduction of c-ErbB-2. However, it inhibited increases in phosphorylation of c-Raf-1 induced by oncogenic c-ErbB-2. Furthermore, azatyrosine inhibited activation of the 12-O-tetradecanoylphorbol-13-acetate (TPA) response element in response to stimulation by oncogenic c-ErbB-2. These results suggest that this agent acts downstream of Ras in signal transduction from oncogenic c-ErbB-2 to nuclear factors. Moreover, we found that azatyrosine was incorporated into proteins instead of tyrosine. The simultaneous presence of a high concentration of tyrosine inhibited the conversion to a normal phenotype of transformed cells by azatyrosine. These results strongly suggest that incorporation of azatyrosine into proteins might convert the transformed cells in to cells with a normal phenotype.

CDK inhibitor, Butyrolactone I inhibited CDK1, 2 and 5 in CDKs. In syncronized human lung fibroblast WI38 cells, it inhibited G1/S transition by inhibiting the phosphorylation of RB protein and G2/M transition by inhibiting the phosphorylation of H1 histone. Also, it selectively inhibited the initiation of DNA replication. The MMP inhibitor, BE16627B, reversively inhibited metalloproteinases including MMPs. It showed the MMP-dependent inhibition of the growth and metastasis of human tumor cells in nude mice without any cytotoxicity and severe side effects. The MMP inhibitor, Marimastat, showed remarkable prolongation of the life span of patients with pancreatic tumors in clinical trials.

Most tumor cells have abnormalities in the cell-cycle regulation system. Cyclin-dependent kinases (cdk) are major regulatory molecules for the cell cycle control. Therefore, cell cycle inhibitors, especially cdk-inhibitors, may be a promising new type of antitumor drug. In this review, low-molecular-weight cell-cycle inhibitors isolated from mainly microorganisms are described. As the activation of cdk is caused by the association with cyclins as well as by their phosphorylation and dephosphorylation, kinase inhibitors and phosphatase inhibitors are also candidates for cell cycle inhibitors.

Protein tyrosine kinases are critical enzymes in regulating cellular growth and differentiation and are also deeply involved in oncogenesis since they are frequently activated in a variety of human cancers. Novel compounds that inhibit epidermal growth factor receptors (EGF-R) with high specificity and potency were developed, and their antitumor effects on EGF-R overexpressing cells and in vivo tumor models were demonstrated. Novel compounds that preferentially inhibit human glioma cells expressing truncated rather than wild-type EGF-R were also developed. Tyrphostin analogs which inhibit angiogenesis and thereby suppress tumor cell growth were also identified by screening inhibitors of Flk-1 tyrosine kinase.

Microtubules are one of the major filament of the cytoskelton and play a role in various biological functions such as mitosis, cell motility and intracellular transport. Therefore, microtubules are considered one of the most important molecular targets for cancer chemotherapy. Tubulin is one of the major microtubular components, and its polymerization and depolymerization regulate microtubular dynamics. Other microtubular components such as microtubule-associated protein (MAPs), actin, and intermediate and microfilaments have also been demonstrated to be involved in microtubular dynamics. Recent studies provide evidence that the functions of MAPs and filaments in microtubule assembly are regulated by phosphorylation, which is catalyzed by mitogenactivated protein kinase (MAP kinase) and cdc2 kinase. Antimitotic agents that disrupt microtubules can be classified in two categories according to the mechanism of action, vinca alkaloids and taxanes. Vinca alkoloids, estramustine, rhizoxin, and E7010 inhibit microtubule polymerization. In contrast, taxanes such as paclitaxel and docetaxel promote polymerization of microtubules and enhance microtubule stability. We have demonstrated that paclitaxel inhibits the catalytic activity of MAP kinase and cdc2 kinase in lung cancer cell lines. This biological effect may be responsible for the increased affinity between MAP2 and tubulins, resulting in promotion of microtubule assembly. Factors that contribute to the resistance to antimitotic agents include intracellular accumulation of the drugs, genetic or functional alternations in tubulin, and alternations in MAP kinase cascade. Antimitotic agents showed a broad spectrum of preclinical antitumor activity. Clinical trials of taxanes revealed that they were effective for several cancers which were advanced or resistant against other anticancer drugs, especially for breast cancers, ovarian cancers and non-small cell lung cancers.

RAS controls at least two signaling pathways, one regulating extracellular signal-regulated kinase (ERK) activation and the other controlling membrane ruffling formation. Activating RAS mutations are commonly found in human tumors, making RAS and its downstream signaling pathways important targets for tumor therapeutics. We have developed a reporter-gene based assay system, utilizing transformation sensitive alpha-actin promoter, to identify compounds that inhibit the transforming activity of RAS either directly or indirectly. SCH51344 is a pyrazolo-quinoline derivative, identified based on its ability to depreprses alpha-actin promoter in RAS-transformed cells and shown to be a potent inhibitor of RAS-transformation. However, this compound had very little effect on the activities of the proteins in the ERK pathway, suggesting that it inhibits RAS-transformation by a novel mechanism and acts on a signaling pathway distinct from ERK pathway. Recently, in collaboration with Dr. Dafna Bar-Sagi's group, we have shown that SCH51344 inhibits membrane ruffling induced by activated forms of H-RAS, K-RAS, N-RAS and RAC. Treatment of fibroblast cells with this compound had very little effect on RAS-mediated activation of ERK and Jun kinase activities. Our results indicate that SCH51344 inhibits a critical component of the membrane ruffling pathway downstream from RAC and suggest that targeting the membrane ruffling pathway may be an effective approach to inhibit transformation by RAS.

Human spermatozoa were exposed to Mitomycin C (MM() at the concentrations of 7.5, 15, 3O micrograms/ml for 1 hour respectively before interspecific in vitro fertilization with zona-free hamster ova. The first cleavage metaphases was analyzed to investigate MMC-induced effects on human spermatozoa. The results showed a distinct dose-response relationship in the induction of chromosomal aberrations. The chromatid aberrations were the predominant types in MMC-induced changes. Some chromosome-type aberrations were also observed. This suggested that the induced effects of MMC on human spermatozoa were some different from that of ultraviolet light-like clastogens on somatic cells. 36.89% of MMC-induced aberrations were rejoining-type. This indicated that the DNA repair systems present in golden hamster oocytes were effective in repairing MMC-induced DNA lesions in human spermatozoa.

A late Phase II multicenter study with menogaril was conducted nationwide in patients with malignant lymphoma [non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD)], and ATLL, menogaril was orally administered at 100 mg daily after breakfast, for seven consecutive days with two- or three-week drug withdrawal, then menogaril administration was repeated. For malignant lymphoma, in 81 patients with NHL and 5 patients with HD registered, 70 and 5 patients were evaluable for efficacy, respectively. The efficacy rates were 32.9% (6 CRs + 17 PRs/70) for NHL and 20.0% (1 PR/5) for HD, respectively; that for the NHL patients with prior anthracycline antibiotic chemotherapy was 30.5% (5 CRs and 13 PRs/59). For ATLL, among the 16 patients registered, 15 were evaluable for efficacy, and the efficacy rate was 40.0% (2 CRs and 4 PRs/15). Adverse drug reactions frequently observed in the patients with malignant lymphoma and ATLL included bone-marrow suppression and gastrointestinal symptoms such as anorexia, and nausea/vomiting. With these results, menogaril was considered to be effective for the treatment of non-Hodgkin's lymphoma and ATLL.

An early Phase II study with TUT-7 (menogaril), a new anthracycline antitumor antibiotic, was conducted in patients with various malignant tumors at 81 departments of 65 institutions nationwide. One course of TUT-7 treatment consisted of seven (7) or fourteen (14) consecutive days of administration at 75 or 100 mg/body/day with two-week drug withdrawal; at least two courses of treatment were given in principle. Among the 165 patients registered, 145 patients were eligible and 128 patients were evaluable for antitumor efficacy. In 11 patients with malignant lymphoma, one (1) had CR and five (5) had PR (54.5%); in three (3) patients with prostate cancer, one (1) had PR (33.3%); and in 12 patients with uterine cervical cancer, two (2) had PR (16.7%). Adverse drug reactions frequently observed were digestive organ disorders (anorexia and nausea/vomiting) and malaise. The abnormality in laboratory tests observed frequently was myelosuppression (leukopenia and neutropenia).

The chronomodulation of anticancer drugs arouses our interest as a method for cancer chemotherapy. The author reviewed recent clinical studies regarding circadian rhythms in 1) target tissues: healthy and cancer tissues; 2) chronopharmacology of anticancer drugs; and 3) chronotoxicity of anticancer drugs. A brief review is made of the main results of clinical phase II trials.

A 56-year-old woman was admitted for evaluation of petechiae and acute promyelocytic leukemia was diagnosed. Administration of all-trans retinoic acid (ATRA) at 60 mg per day was begun. On the same day, high fever was recognized. There was no evidence of infection nor other organ dysfunction. Administration of steroid caused a resolution of the fever. The same phenomenon was observed three times subsequently. High fever was the adverse reaction in this patient during the treatment of ATRA, and steroid was dramatically effective.

The purpose of this study was to explore the effect of daily administration of oral etoposide (25 mg) for patients with non-small cell lung cancer treated with concurrent radiation therapy. Planned endpoints were response, survival and toxicity. Forty-one patients with non-small cell lung cancer were divided into 25 patients given daily oral etoposide (25 mg) with concurrent radiation therapy (ERT group) and 16 patients given radiation therapy alone (RT group). Etoposide was administrated in the morning throughout radiation therapy. The median total irradiated dose was 63.1 Gy in the ERT group and 64.0 Gy in the RT group. Twenty-four patients completed therapy in the ERT group and 16 in the RT group. Three (15%) ERT patients achieved complete response (CR) and 9 (45%) achieved partial response (PR). In the RT group, no patients achieved CR and 9 (69%) achieved PR. One-year survival was 22.6% with ERT and 23.0% with RT. The prognosis of stage III patients in the ERT group was worse than that in the RT group because radiation pneumonitis and radiation esophagitis were more severe with ERT. In conclusion, the ERT group had better local response but worse in survival than the RT group. Complications of ERT were severe enough to cause death in some patients. ERT had no clear advantage over RT.

We examined the mechanism of the reduction of metastatic liver tumors in rats treated with angiogenesis inhibitor TNP-470 on the histological basis of patterns of tumor cell death. Metastatic tumors were developed by intravenous injection of AH-130 cell line, followed by a dose of TNP-470. Alteration in the size and number of metastatic liver tumors and its cell death pattern were analyzed. The number and size of the metastatic tumors at 2 weeks in untreated rats were larger than those in treated rats. The number of tumors in untreated rats decreased, whereas their size increased. All rats treated were alive and free from tumors after 4 weeks, although all untreated rats died of metastatic tumors. Necrosis was predominant in the tumors of untreated rats, while most tumors in treated rats showed apoptosis. Consequently, the metastatic tumor in untreated rats might grow faster than its angiogenesis, suggesting the occurrence of central necrosis due to apparent ischemia. On the other hand, the tumor in treated rats might be reduce a by weak ischemic stimulus, which triggers apoptosis.

Most people drugs are hydrophilic molecules with a molecular weight between 300 and 20,000 and such molecules are usually given by parenteral administration. In many cases, enteral administration of these peptides via the gastrointestinal tract is preferred. However, oral administration of peptides and proteins is often limited by their instability in the gastrointestinal environment and/or poor absorption from the gut. To promote the absorption of these drugs, we first discovered unsaturated fatty acids with absorption enhancing activities and less harmful properties to the gastrointestinal membranes in hydrolysates of natural oil. The mechanisms whereby the permeability of drugs was enhanced by the fatty acids are associated with the disorder in the membrane's interior and the interaction of these fatty acids with the polar head group of phospholipid. Furthermore, we suggested that a SH-related substance was involved in the permeability enhancing effect of these fatty acids. Secondly, we developed a lympho-targeting delivery system for bleomycin by the combined effects of an ion-pair complex with dextran sulfate (DS) and an absorption enhancer. We found a very high lymphatic concentration when administered bleomycin-DS together with the absorption enhancer. Its mechanism may be due to a molecular sieving in the blood-lymph barrier in the intestinal tissues. Finally, to improve the intestinal absorption of peptides, we synthesized novel lipophilic derivatives of peptides including TRH (thyrotropin releasing hormone), tetragastrin, enkephalin, calcitonin and insulin by a chemical modification with fatty acids, while maintaining their pharmacological activities. The stability and permeability of these peptides were improved by acylation with some fatty acids having appropriate carbon numbers. Thus, we have established the strategies for improving the delivery of peptide drugs by various approaches. In future, the combination use of these approaches will be expected to develop the delivery systems of these drugs for therapeutic treatment.