Biomedical subjects

R Kanamaru

Publications and source records attributed to R Kanamaru.

At least 55 records · Page 3Linked to original sources

PubMed1997

Induction of p53-independent apoptosis associated with G2M arrest following DNA damage in human colon cancer cell lines.

The tumor suppressor p53 protein induces apoptosis in response to various kinds of DNA damage in normal cells, but it is still unclear whether or not apoptosis induced by DNA damage correlates with the p53 status in tumor cells. We determined the status of p53 by functional analysis of separated alleles in yeast in five human colon cancer cell lines, SW-480, SW-620, DLD-1, COLO320 and LS174T and investigated whether p53 is necessary for apoptosis and cell cycle arrest after treatment of the cells with a DNA-damaging agent, etoposide (VP-16), or gamma-irradiation. Of these cell lines, only LS174T expresses a functional p53. Apoptosis was detected in SW-480 and COLO320 cell lines, but not in the other cell lines, including LS174T cell line with a normal p53 function. Furthermore, cell cycle analysis revealed accumulation in the G2M phase preceding induction of apoptosis in SW-480 and COLO320 cells, but not in the other cells. These results suggest that apoptotic induction by DNA damage is not necessarily related to p53 status and that induction of p53-independent apoptosis following DNA damage may correlate with G2M arrest in the cell cycle, at least in the colon cancer cell lines used in this study.

Apoptosis↗

PubMed1997

Features of DNA oligonucleosomal fragmentation in human tumor cell lines and its detection by flow cytometry: utility and limitations.

Cultured HL-60, HeLa S3 and WiDr cells were treated with various doses of ethanol, then subjected to flow cytometry and gel electrophoresis of cellular DNA. On electrophoresis of DNA from HL-60 cells treated with 0.5 or 1.0 mM ethanol, a ladder pattern was recognized after 3 h. At higher doses of ethanol (2.0 and 5.0 mM), a smear pattern resulted. On flow cytometry, however, A0 cells (lower fluorescence level than G0+G1 cells) were noted from 0.5 to 5.0 mM ethanol. The observation of A0 cells at higher doses indicated loss of DNA after random DNA degradation. HeLa S3 and WiDr cells were partially detached from flasks after administration of ethanol and separated into adherent and non-adherent categories. In DNA from non-adherent HeLa S3 cells treated with 0.5 mM ethanol, a ladder pattern was observed after 24 h. On flow cytometry, prior to the appearance of A0 cells, an accumulation in the G2 + M-phase became obvious after 3 h. Increased mitotic indices indicated that this phenomenon was due to M-phase arrest. Adherent HeLa S3 cells showed no DNA oligonucleosomal fragmentation or A0 cells. These findings indicate that detection of A0 cells by flow cytometry is not proof of cell death by DNA oligonucleosomal fragmentation.

Apoptosis↗

PubMed1997

[Modification of gene targeting method for functional analysis of the target gene in vivo].

Gene targeting in ES cells is a powerful tool to generate mice bearing predesigned mutations in the germ line. However, these mice carrying such constitutional mutations are often lethal and, therefore, we cannot study other functional aspects of the gene at later stages or in particular tissues. To inactivate the target gene in particular tissues or at particular stages of development, conditional gene inactivation based on the Cre-loxP recombination system of bacteriophage P1 is considered one of the applicable techniques. To express the Cre gene in a cell-type or developmental stage specific manner, either transgenic or adenoviral technology is most considerable technique in vivo.

Animals↗

PubMed1997

[Functional screening of p53 status in tumor cells using Saccharomyces cerevisiae].

We have detected both germ-line and somatic p53 mutations in lymphocytes, cell lines and tumor tissues using a functional analysis of p53 tumor suppressor gene based on yeast transcription assay. Through our screening projects of the p53 gene, a number of missense p53 mutations were identified as loss-of-function mutations. This method, previously termed FASAY, is rapid, sensitive, less-expensive and can be automated for screening both somatic and germ-line p53 mutations.

Genes, p53↗

PubMed1997

[p53 mutation does not determine prognosis in non-Hodgkin's lymphoma].

We studied the clinical significance of the extent of p53 protein expression by immunohistochemical analysis and p53 mutations by functional analysis of p53 in 42 patients with high and intermediate grade of Non-Hodgkin's Lymphoma (NHL). Neither p53 expression nor mutation correlated with short survival or resistance to chemoradiotherapy, implying that p53 mutation is not a prognostic factor in NHL.

Genes, p53↗

PubMed1997

Influence of chemotherapy on FDG uptake by human cancer xenografts in nude mice.

UNLABELLED: This study evaluated the use of PET with 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG) for monitoring chemotherapy effects, using a human cancer xenograft (poorly differentiated human gastric cancer) in vivo model. METHODS: Tumor 18F-FDG uptakes and sizes were measured after administrating mitomycin (MMC), cisplatin (CDDP) and adriamycin (ADR) to xenograft-bearing nude mice and compared with 18F-FDG tumor uptake and tumor size in a non-therapy group. The correlation between the uptake and size was also assessed. RESULTS: The largest reduction in tumor size after chemotherapy occurred in the MMC administered group, followed by the CDDP case, with no reduction in the ADR group as compared to the controls. Fluorine-18-FDG tumor uptake after chemotherapy was also decreased in the MMC and CDDP groups, in that order, but not in the ADR case. With MMC and CDDP, size reduction became significant on Days 8 or 11, whereas 18F-FDG tumor uptake had already been decreased on Days 3 or 7. CONCLUSION: Fluorine-18-FDG uptake decreases in parallel to the efficacy of anticancer agents and correlates with subsequent morphologic changes. We conclude that 18F-FDG PET tumor images are indeed useful for monitoring the effects of cancer chemotherapy.

Adenocarcinoma↗

PubMed1997

Enhancement of chemotherapeutic effects with focused shock waves: extracorporeal shock wave chemotherapy (ESWC).

The effects of shock waves in combination with various anti-cancer agents i.e. Bleomycin(BLM), Cis-platinum (CDDP) and 5-fluorouracil(5-FU) on various human cancer cells were examined. It was only with BLM that enhancement was evident in all cell lines. The degree of chemotherapeutic enhancement was proportional to the amount of shock wave energy applied. Ladder formation of DNA in GCIY, a gastric cell line, was observed only when treated with both BLM and shock waves in combination. When SW 480, a colon cancer cell line, transplanted into the back of nude mice were treated with a combination of i.v. injected BLM and regional exposure to shock waves, a significant enhancement of chemotherapeutic effects was observed in terms of the tumor growth curve. When cancer cells exposed to shock waves and observed under scanning and transmission electron microscopes, microvilli on the cell surface disappeared and numerous dimples(diameters distributed from 0.05 to 0.5 microns) became apparent. These dimples were concluded to be pores penetrating through the cell membrane, because reagents such as propidium iodide or 5(6)-carboxyfluorescein could enter cells treated shock waves.

Animals↗

PubMed1997

[p53 as a molecular target for cancer therapy].

Development of novel strategies is required for cancer treatment because most human tumors are refractory to current conventional therapy. During the past decade, a number of oncogenes and tumor suppressor genes have been cloned and the molecular mechanisms as to how mutations in such genes contribute to tumor development are going to be clarified. It is, therefore, a great challenge to develop novel strategies for tumor specific therapy based on molecular biology of cancer. p53 tumor suppressor gene is one of the most frequently mutated genes in a variety of human cancers. This review paper introduces several recent approaches related to the p53 as a molecular target of cancer treatment, including (i) p53 status and chemo-radiosensitivity, (ii) p53 gene therapy, (iii) E1B-deficient adenovirus and (iv) restoration of p53 function by synthetic polypeptides.

Animals↗

PubMed1997

[Phase I study of S-1. S-1 Study Group].

We have conducted Phase I study of a novel oral antitumor agent of fluorinated pyrimidines, S-1, in which tegafur (FT) is combined with two classes of modulator, 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate (Oxo) at a molar ratio of FT:CDHP:Oxo = 1:0.4:1 as a multi-center study with 16 institutions nationwide. Two administration methods, once and twice daily administrations, were evaluated. As a result, MAD was determined as 150 mg/body/day approximately 200 mg/body/day and 75 mg/body x2/day approximately 100 mg/body x2/day, respectively. DLF was myelosuppression, mainly consisting of leukopenia in the two administrations. Most adverse reactions observed, including myelosuppression, disappeared by discontinuation of administration, and recovery was in about 2 weeks. Adverse reactions other than myelosuppression which induced the discontinuation were rash and vomiting. Other adverse reactions observed were anorexia, malaise, diarrhea and stomatitis. Diarrhea and stomatitis were mild (Grade 1), except those observed at a dose of 200 mg/body/day, and did not induce discontinuation of administration. Based on these findings and pharmacokinetic evaluation, the recommended dose and administration for Early Phase II studies were determined as twice daily administration of 75 mg/body for 28 consecutive days with 14 days rest (1 course).

Administration, Oral↗

PubMed1996

Enhancing the effect of anticancer drugs against the colorectal cancer cell line with electroporation.

Electroporation was applied in vitro and in vivo in the treatment of human colorectal cancer cell lines to study whether it can enhance the effect of bleomycin (BLM), 5-fluorouracil (5-FU) and cis-platinum (CDDP). We used LS174T and Colo320 cells derived from human colon cancer as target cells in this study. When the LS174T cells were used as target cells, the IC50 of BLM decreased to 10(-3) times, while that of 5-FU decreased to only about one fifth with the application of electric current. In the case of the Colo320 cells, the IC50 of BLM and 5-FU were about one hundredth and a half, respectively. The effect of CDDP was not enhanced with electric current. In vivo experiments were also performed using LS174T cells transplanted subcutaneously (s.c.) into nude mice. By treatment with intravenously (i.v.) administered BLM and simultaneous application of the electric current, tumors were markedly decreased in size after three weeks.

Animals↗

PubMed1996

[Phase I study on DMDC].

Phase I study on antimetabolic carcinostatic DMDC was conducted at 16 medical institutions nationwide for patients with various types of malignant tumors. DMDC was administered by intravenous infusion as per the following three schedules: single administration, single repeated administration, and 5-consecutive-day administration. The safety of the compound was examined single administration in 16 patients, by the single repeated administration in 5 patients, and by the 5 consecutive-day administration in 7 patients, for a total of 28 patients. In the single administration trial, 200 mg/m2 (1 n) was given as an initial dose, then increased stepwise to 450 mg/m2 (2.25 n). The single repeated administration trial was conducted at a single dose of 300 mg/m2. One treatment course lasts until recovery from side effects and abnormalities in laboratory test values. As a general rule, the administration was repeated for 2 treatment courses or more. In the 5-consecutive-day administration trial, an initial dose was 30 mg/m2/day (1 n), and increased to 40 mg/m2/day (1.3 n). The dose-limiting factors for both the single and 5-consecutive-day administration trials were decreases in the numbers of leukocytes and neutrophils. The maximum tolerated dose for single administration trial was over 400 mg/m2 (2 n), and for the 5-consecutive-day administration trial 40 mg/m2 (1.3 n). The decrease in the number of leukocytes and neutrophils for both the single administration and 5-consecutive-day administration trial reached its nadir one to two weeks after administration, and recovered in about one week. In the single repeated administration trial, the administration interval for patients who had completed 2 courses was 2 approximately 3 weeks. The plasma half-life of DMDC in the final phase of elimination in the single administration trial was 5.2 approximately 6.3 hours, and no differences were seen among dose levels. The urinary excretion rate was between 32.0 approximately 61.5% until 48 hours after administration. No accumulation was seen in the 5-consecutive-day administration trial. There were no findings to suggest an antitumor effect in the present study. Given the recovery pattern for suppression of marrow, the above mentioned results led us to decide that an recommended method of administration and dosage in an early phase II trial would be 300 mg/m2 per administration by an intravenous infusion every 2 approximately 3 weeks.

Aged↗

PubMed1995

[Clinical phase III study of tropisetron capsule in the treatment of nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs].

A clinical phase III study of tropisetron capsule was conducted to assess its efficacy, safety and usefulness on nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs. The study was conducted in patients who experienced vomiting on previous chemotherapy. Tropisetron 5 mg capsule was given to patients once 2 hours prior to the first administration of either carboplatin or non-platinum anti-cancer drugs; the patients were then observed for nausea and/or vomiting during 24 hours after the first administration. Some 56.7% (17/30) of the patients did not vomit after tropisetron administration, and the frequency of vomiting was significantly reduced compared with that during the previous chemotherapy. Further, in the clinical efficacy ratings, in which the efficacy was assessed on the basis of the nausea and vomiting data, 83.3% (25/30) of cases were rated as "effective or better". Adverse events observed were 3 cases of mild headache, but these were not clinically problematic. The above results reveal that tropisetron capsule is significantly effective and safe in the treatment of nausea and vomiting induced by carboplatin or non-platinum anti-cancer drugs; in addition, tropisetron proved to be highly useful for its convenience as an oral agent.

Adult↗

PubMed1995

[The clinical phase I study of TNP-351. The TNP-351 Research Committee].

The clinical phase I study of TNP-351, an antifolate drug having a novel structure, was performed through a multicenter cooperative program in 40 patients with solid tumors. The test drug was used on dosage schedules of single and daily doses for 5 or 3 days (by intravenous drip over 30 minutes, respectively). From the daily administration for 5 days, severe adverse reactions such as myelosuppression, became manifest at 5 mg/m2 (1n). This schedule was then switched to daily administration for 3 days. Administration of the test drug was initiated at a dose of 5 mg/m2. On a single-dose schedule, the dose was increased up to 100 mg/m2 (20 n), and on the 3-day daily administration schedule, up to 10.8 mg/m2 (2.2 n). Consequently, 26 of the study patients received single doses; three of them the 5-day daily administration, and 11 the 3-day daily administration. The dose-limiting factors were leukopenia and thrombopenia on both the single-dose and 3-day daily administration schedules. MTD was 100 mg/m2, and MAD, 75 mg/m2 for the single-dose schedule; and 10.8 mg/m2 and 9 mg/m2 for the 3-day daily administration schedule. WBC and platelet counts fell to nadirs at 1-2 weeks on either the single-dose or 3-day daily administration schedule, and it took the respective parameters about 1 week to recover. Subjective and objective adverse reactions to the test drug consisted of digestive tract disorders manifested as stomatitis, anorexia, nausea and vomiting; and laboratory abnormalities such as elevations of GOT and GPT in addition to the myelosuppression. Many of these adverse reactions subsided within 3 weeks after initiation of TNP-351 treatment. On the single-dose schedule, the test drug occurred chiefly in unchanged form in the blood, and in this form it disappeared from the blood biphasically with an alpha phase of 0.29-0.95 hours, and a beta phase of 7.8-14.4 hours. This disappearance pattern did not vary with an increase in dose. The 24-hour urinary excretion rate of the unchanged form amounted to 42-62% of the administered doses. On the 3-day daily administration schedule, the test drug was not accumulated in vivo. In the present study, two patients with malignant fibrous histiocytoma responded to the test drug with tumor regression. The results suggested that the recommended dosage regimen for the clinical early phase II study of the test drug should comprise a course of 9 mg/m2/day (by intravenous drip infusion over 30 minutes) every day for 3 days, which should be repeated every 3 weeks.

Adult↗

PubMed1995

[Phase 3 multicenter clinical study of 111In-DTPA-D-octreotide (MP-1727) in patients with gastrointestinal hormone producing tumors].

A phase 3 multicenter clinical study was performed to investigate the efficacy, safety and usefulness of MP-1727, a novel tumor imaging agent which binds to somatostatin receptors, in 23 patients with gastrointestinal hormone producing tumor. The efficacy was graded effective or very effective in 16 cases (76.2%) out of 21 cases who could be evaluated. Positive predictive accuracy was 77.8% (7/9) for carcinoids, 100% (5/5) for gastrinomas and 40.0% (2/5) for insulinomas. In three cases, tumor lesions which had been unknown were detected by MP-1727 scintigraphy. The consistent ratio between scintigraphically positive sites and preinjection localizations was 82.0% (41/50 sites) in total. Although adverse drug reactions were observed in two cases, the safety was graded 'not problematic at all' in all of 23 cases. These results show that MP-1727 is a very useful radiopharmaceutical for detection and localization of gastrointestinal hormone producing tumors.

Adult↗

PubMed1994

The cDNA sequence encoding mouse Mg2+ -dependent protein phosphatase alpha.

The complete cDNA sequence encoding Mg2+ -dependent protein phosphatase (MPP) alpha from mouse brain was cloned. It encodes a protein of 382 amino acids with a calculated M(r) of 42,432. The putative sites of phosphorylation by casein kinase II, found originally in rat MPP alpha, are conserved in the mouse ortholog.

Amino Acid Sequence↗

PubMed1994

Restriction fragment length polymorphism of the human CYP2E1 (cytochrome P450IIE1) gene and susceptibility to lung cancer: possible relevance to low smoking exposure.

Polymorphic metabolism of certain chemical carcinogens may result in differences in susceptibility to cancers. Human CYP2E1 (cytochrome P450IIE1) is an enzyme involved in the metabolic activation of precarcinogens such as nitrosamines. We detected a restriction fragment length polymorphism (RFLP) of the human CYP2E1 gene for the restriction endonuclease Dra I. The distribution of this polymorphism was examined among lung cancer patients (n = 91), patients with cancer of the digestive tract (n = 45) and controls (n = 76). A significant difference in the distribution was observed between lung cancer patients and controls (chi 2 = 11.4 with 2 df; p < 0.005). On the other hand, there was no significant difference between patients between cancer of the digestive tract and controls (chi 2 = 4.87 with 2 df; NS). This finding suggests that the Dra I polymorphism of the CYP2E1 gene is associated with susceptibility to lung cancer. In addition, an association was found between the amount of lifelong smoking exposure and the distribution of the genotypes of the RFLP among lung cancer patients. The distribution pattern seemed deviated from that of controls especially in the population of low smoking exposure. Our Northern blot analysis data using RNA from human liver autopsy samples suggest that the Dra I polymorphism might be associated with the gene expression of CYP2E1 at mRNA level.

Aged↗

PubMed1994

[Effect of a new anticancer drug, docetaxel (RP56976), on human leukemia cell lines].

The antitumor effect of a new derivative of taxol, docetaxel (RP56976), was examined in K562 human tumor system in vitro. K562 cells presenting a multidrug resistant phenotype showed cross resistance to docetaxel. However, the resistance levels of docetaxel in these cell lines were much lower than for adriamycin and vincristine. Flow cytometric analysis showed the accumulation of cells into G2/M phase after 18hrs. Wright-Giemsa staining showed a marked increase of metaphase population. Docetaxel was shown to promote the assembly of microtubule protein without GTP in vitro, but no inhibitory effect on DNA, RNA and protein synthesis. Moreover, topoisomerase activities were not affected by docetaxel. These results indicate that docetaxel acts as a strong mitotic inhibitor in cancer chemotherapy.

Antineoplastic Agents, Phytogenic↗

PubMed1994

[Phase I clinical trial of RP 56976 (docetaxel) a new anticancer drug].

A multicenter phase I clinical trial of RP 56976 (docetaxel), a new anticancer drug, was performed with single and repeated doses. Based on the results of phase I clinical trials conducted in the United States and Europe, the starting dose was 10 mg/m2. The dose was subsequently increased to 20, 50, 70 and 90 mg/m2. A dose of 60 mg/m2 was additionally tested. Single administrations of the six dose levels were performed in a total of 27 patients via intravenous drip infusion over one hour. Ten of the patients subsequently received repeated doses at three of the dose levels in the same manner. The dose limiting factor (DLF) of docetaxel is leukopenia (especially, neutropenia). Based on the observation of the DLF, the maximum tolerated dose (MTD) was determined to be 70-90 mg/m2. The white blood cell count reached a nadir about 9.5-19.5 days (median) after administration, and took 7-11 days (median) to recover. Other adverse reactions observed were nausea/vomiting anorexia, alopecia, diarrhea, fatigue and fever, which were all acceptable. The results of this trial suggest that a dosage regimen of 60 mg/m2 at 3- to 4 week intervals is appropriate in an early phase II clinical trial.

Adolescent↗