PubMed Health⌕ Search

Biomedical subjects

F Kanzawa

Publications and source records attributed to F Kanzawa.

At least 37 records · Page 2Linked to original sources
PubMed1990

Establishment of a camptothecin analogue (CPT-11)-resistant cell line of human non-small cell lung cancer: characterization and mechanism of resistance.

Camptothecin-11 (CPT-11) is a new derivative of camptothecin, a plant alkaloid antitumor agent, and a good candidate for clinical trials because of higher antitumor activity, less toxicity, and high aqueous solubility. CPT-11 is known to be altered into an active form, SN-38, by esterase in in vivo. CPT-11-resistant cells (PC-7/CPT) established from a human non-small cell lung cancer cell (PC-7) by stepwise, continuous treatment with CPT-11 exhibit about a 10-fold increase in resistance to the drug. CPT-11-resistant cells show a moderate cross-resistance to camptothecin (x8.6) and SN-38 (x8.6), and weak cross-resistance to Adriamycin (x2.2) and 5-fluorouracil (x2.4). The comparative studies between the parent (PC-7) and resistant (PC-7/CPT) cell lines with respect to their growth characterization shows a longer cell doubling time (45.8 versus 35.5 h), a lower cloning efficiency (3.2 versus 7.1%), and a lower population of S-phase cells (26.4 versus 36.0%) in the CPT-11-resistant cells. This observation may partly explain the resistance to CPT-11, a drug whose activity is cell cycle specific. Accumulation of CPT-11 is nearly the same in both cell lines. However, the intracellular concentration of SN-38 formed in the parent cells was 2-fold greater than in the CPT-11-resistant cells. This alteration may affect to some extent to the resistance. As assayed by relaxation of supercoiled plasmid DNA, the total activity of DNA topoisomerase I from the CPT-11-resistant cells was shown to be reduced to one-fourth its level in sensitive cells. The reduced activity was caused by a reduction of amount of DNA topoisomerase I. Furthermore, the enzyme from the resistant cells was shown to be 5-fold more resistant to CPT-11 than the enzyme from the parent cells. Thus, decreased total activity of topoisomerase I may play an important role in cellular resistance to CPT-11, and it appears that this decreased activity is due to a resistant form of topoisomerase I in CPT-11 resistant cells.

Antineoplastic Agents, Phytogenic↗
PubMed1990

Characterization of an etoposide-resistant human small-cell lung cancer cell line.

We established an etoposide (VP-16)-resistant human small-cell lung cancer cell line (H69/VP) by stepwise exposure to VP-16. The resistance of H69/VP to VP-16 was 9.4-fold that of the parent cell line (H69/P). H69/VP showed cross-resistance to Adriamycin (ADM), (4S)-4,11-diethyl-4-hydroxy-9-[(4-piperidinopiperidino) carbonyloxy]-1H-pyrano[3',4':6,7]indolizino [1,2-b]quinoline-3,14(4H,12H)-dionehydrochloride trihydrate (CPT-11), teniposide (VM-26), vindesine (VDS) and vincristine (VCR). The amount of DNA topoisomerase II (topo.II) was nearly the same in H69/P and H69/VP cells. The catalytic activity of topo.II in H69/VP cells was lower than that in the H69/P line. Accumulation of [3H]-VP-16 in H69/VP was 6.1-7.5 times lower than that in H69/P. According to Northern blot analysis, the mdr-1 mRNA level in H69/VP was markedly higher than that in H69/P. These findings suggest that H69/VP has a typical multidrug resistance (MDR) phenotype and that alteration of the drug accumulation mediated by P-glycoprotein may play an important role in resistance to VP-16. Reduced topo.II activity may also be associated with VP-16 resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1987

A new antitumor antibiotic FR66973: clonogenic in vitro assessment of activity against human non-small cell lung carcinoma.

We have utilized a human tumor clonogenic assay (HTCA), as a disease-oriented drug screening model of new antitumor drugs, to test the antitumor activity of FR66973 and compared the activity with that of its analogous compound, mitomycin C. The overall in vitro response rate (defined as less than 50% survival of tumor colony forming units) for FR66973 against fresh tumor cells obtained from patients with non-small cell lung carcinoma (NSCLC) was 32%, 50% and 89% at 0.1, 1 and 10 micrograms/ml, respectively, which was superior to that of mitomycin C at the corresponding concentration. Our data suggest that FR66973 is a promising new drug against NSCLC. If phase I toxicities are not prohibitive, FR66973 may also have good activity against NSCLC in clinical phase II trial.

Adult↗
PubMed1987

In vitro antitumor effect of recombinant human tumor necrotizing factor on cultured human cancer cell lines and freshly isolated lung cancer cells by the human tumor clonogenic assay.

In vitro antitumor effects of human recombinant tumor necrotizing factor (rH-TNF) were examined against nine lung cancer cell lines including six non small and three small cell lung cancer, four stomach cancer cell lines and 30 freshly isolated lung cancer cell samples by the human tumor clonogenic assay. rH-TNF did not show any inhibitory effect on the colony formations of lung and stomach cancer cell lines, except for PC10 established from squamous cell carcinoma even at the high concentration. The overall response rate of fresh material was 11.5%. The colony formations of only two materials from 20 patients without prior chemotherapy were significantly suppressed by rH-TNF in vitro. Three specimens of adenocarcinoma exhibited more than 70% decrease in colony number by treating with 100 and 1000 u/ml of rH-TNF resulting in the response rate of 15.8% (3/19). From these results, it can be concluded that rH-TNF has modest direct cytotoxic effect on lung cancer, and additional study against adenocarcinoma of the lung might be warranted.

Antineoplastic Agents↗
PubMed1987

The different effects of recombinant human tumor necrosis factor on rat fibrosarcoma sublines.

The antitumor effect of recombinant human tumor necrosis factor (rH-TNF) on two clones of rat fibrosarcoma with different metastatic potential to lymph nodes was examined. The colony formation of clone A, which has high metastatic potential, was completely inhibited by continuous exposure to rH-TNF at 50 U/ml. In contrast, colony formation of clone G, which has low metastatic potential, was not inhibited by high concentrations of rH-TNF (10,000 U/ml). The inhibitory effect of rH-TNF on colony formation by clone A was also observed with a 1-h exposure to rH-TNF. This effect was time and concentration dependent, as determined by the colony assay, 3H-thymidine uptake assay, and 51Cr-release assay. 3H-thymidine and 3H-uridine uptake per cell of clone A exposed to rH-TNF was not decreased. This suggests that the mechanisms of the antitumor effect of rH-TNF were not due to inhibition of DNA and RNA synthesis of tumor cells. In vivo growth and lymph node metastases of clone A inoculated i.p. to Donryu strain rats were completely suppressed by 14 consecutive i.p. injections of 10(5) or 10(6) U/kg per day of rH-TNF. On the other hand the growth of clone G was not influenced by rH-TNF administration.

Animals↗
PubMed1987

Human tumor clonogenic assay for carcinoma of the lung. II. Factors that influence colony formation in soft agar.

The human tumor clonogenic assay (HTCA) has potential value for studies of both the chemosensitivity and biology of human tumors. However, many technical problems including low plating efficiencies and the preparation of sufficient numbers of viable cells remain. In this study, an improved method for disaggregation of solid tumors increased the yield of single cells. Consequently, more than 10 anticancer drugs could be tested in 94 of 168 specimens (56%). Removal of peripheral blood lymphocytes from cell suspensions derived from effusions also improved colony formation. Adequate growth for sensitivity testing (greater than 30 colonies/plate) was obtained in 122 cases (73%), inadequate growth for drug evaluation (5-29 colonies/plate) in 29 cases (17%), and no colony formation (less than 5 colonies/plate) in 17 cases (10%) of the 168 viable samples. The cloning efficiencies of cells derived from primary tumors (median 0.015%) were higher than those of cells derived from metastatic tumors (0.012%), and they varied with the location of the metastatic site. Cloning efficiencies varied markedly from specimen to specimen, and were unaffected by tumor histology, grade of differentiation, patient age, stage of disease, or prior chemotherapy. The HTCA is promising as a potential tool for studying the biology of tumors.

Agar↗
PubMed1987

Antitumor activity of quinocarmycin against carcinoma of the lung in human tumor clonogenic assay.

Quinocarmycin monocitrate is a novel antitumor antibiotic isolated from Streptomyces melanovinaceus. We have utilized a human tumor clonogenic assay to test the antitumor activity of this drug against carcinoma of the lung and to compare its activity with those of mitomycin C or cisplatin, which are components of the clinically effective regimens in therapy for this disease. The overall in vitro response rate (defined as less than 50% survival of tumor colony forming units) for quinocarmycin at 0.1 and 1.0 microgram/ml continuous exposure was 42% and 72%, respectively, which was superior to that of other drugs. Quinocarmycin and other antitumor drugs do not have identical spectra of antitumor activities in vitro, suggesting that this compound with good in vitro activity should be further developed for clinical trials.

Adenocarcinoma↗
PubMed1987

Comparative studies of pulse and continuous exposure in human tumor clonogenic assay.

To assess the influence of different schedules of drug exposure in human tumor clonogenic assay on in vitro cytotoxicity of antitumor drugs, the in vitro sensitivities of a human carcinoma cell line, PC-9, to various antitumor drugs were measured by using two different procedures: exposure was either by pulse for 1 h prior to plating or continuous throughout the period of growth in agar. Marked differences between the two procedures in testing actinomycin D, etoposide, 5-fluorouracil, vinblastine and vindesine but not in adriamycin, daunomycin, melphalan, nimustine and ranomustine were observed. The former and the latter were classified as schedule dependent drugs and a schedule independent drugs, respectively. In this study, the schedule dependency of in vitro drug response appears to be related mainly to time-dependency and partially to other factors, such as stability during culture in medium.

Adenocarcinoma↗
PubMed1987

[In vitro drug sensitivity test].

Human tumor clonogenic assay(HTCA) not only offers potential advantages for prediction of the sensitivity of individual patients, to anticancer drugs, but also for the development and preclinical testing of prospective new antineoplastic agents. However, HTCA has several theoretical and technical problems, such as a low success rate, the requirement of large numbers of tumor cells and the long time period necessary for evaluation. In order to solve these problems, the MINI-hybrid assay has been developed. We reviewed our experiences to date with chemosensitivity testing by MINI-hybrid assay. Twenty-two of 23 tumors gave evaluable chemosensitivity results (95.6%), and the range of thymidine incorporation for evaluable assays was 7 X 10(2)-1.2 X 10(5)cpm. In addition, the results of drug sensitivity testing of cultured cell lines by MINI-hybrid assay were well correlated with those obtained by HTCA. With its high evaluability rates, the need for fewer cells, the short duration (5 days) required and ease of quantitation, the MINI-hybrid assay is widely applicable to the chemosensitivity testing of human tumors.

Antineoplastic Agents↗
PubMed1986

Antitumor activity of alkylesters of 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) against murine lymphoma L5178Y resistant to 5-fluoro-2'-deoxyuridine.

A series of twenty six 5'-substituted FdUMP (5-fluoro-2'-deoxyuridine 5'-monophosphate) have been evaluated for their inhibitory effects on the proliferation of murine lymphoma L5178Y cells sensitive or resistant to FUdR (5-fluoro-2'-deoxyuridine). 5'-Octylphenylene-FdUMP was the most active among these active derivatives against the parent cell line (L5178Y/P). Several other FdUMP derivatives also proved as potent as FUdR in their antiproliferating activity on the L5178Y/P cell line. Activity of these derivatives was decreased considerably by a substituent with a long aliphatic chain and the introduction of acyl groups on the C-3' position. Eicosyl-FdUMP was found to show no or low cross-resistance on the L5178Y/FUdR subline which was about 19 000-fold resistant to FUdR compared with the parent cell line. This derivative might penetrate cell membrane in an intact form and be converted into FdUMP by a phosphodiesterase inside the cell, because an anabolic enzyme, deoxyuridine kinase, was defective in cells of the L5178Y/FUdR subline. The derivatives were promising as antitumor agents for the treatment of relapsed patients following 5-fluorouracil therapy.

Animals↗
PubMed1986

In vitro chemosensitivity patterns of carcinoma of the lung in human tumor clonogenic assay.

One hundred and sixty-eight different specimens of human carcinoma of the lung were tested for in vitro drug sensitivity using the human tumor clonogenic assay (HTCA) originally described by Hamburger and Salmon. One hundred and twenty-two (73%) specimens grew adequately for chemosensitivity testing. Most tumors were resistant to chemotherapeutic drugs, but in vitro sensitivity, regardless of the type of drugs, varied markedly from specimen to specimen. Although response rates to individual drugs ranged between 9% and 23%, half the specimens tested were sensitive in vitro to at least one drug. A higher in vitro sensitivity rate was observed in small cell lung carcinoma (31%) than in non-small cell lung carcinoma (17%). The frequency of in vitro sensitivity was greater for patients who had received no prior chemotherapy than those who were in relapse. These in vitro results are similar to current clinical experience. There was a significant association between in vitro sensitivity of cells from a primary tumor as compared to its metastases. Overall HTCA appears to be useful in selecting appropriate chemotherapy for individual patients with carcinoma of the lung.

Antineoplastic Agents↗
PubMed1986

A bioassay of cisplatin by human tumor clonogenic assay.

A new bioassay method for cis-diamminedichloroplatinum (CDDP) using a human tumor clonogenic assay (HTCA) was developed and used to examine the pharmacokinetics of the active form of CDDP in different schedules of administration. The inhibition of colony growth of tumor cells decreased with increase in the % of fetal calf serum in RPMI1640 containing CDDP. By means of this assay, four administration schedules (A, B, C and D) of CDDP were examined. In patients given 40 mg/m2 of CDDP by iv infusion on day 1 twice with a 1 hr interval (schedule A), total platinum was still detectable in plasma at 6 hr by atomic absorption assay. However, the active form of CDDP was no longer detectable at 30 min. In patients treated with 20 mg/m2 of CDDP iv for 20 min daily (schedule B) from day 1 to day 4, the level of total platinum showed a cumulative increase. However, the active form of CDDP was no longer detectable at 30 min, and no cumulative effect was observed. In patients given a high dose (120 mg/m2) of CDDP iv for 30 min on day 1 (schedule C), the peak concentration of active form of CDDP was determined to be 5.0 to 7.0 micrograms/ml, and a level of more than 1.0 micrograms/ml was maintained even after 2 hr in one case. In 2 patients of this group the concentrations of active form of CDDP determined by HTCA were the same as those of ultrafiltrable platinum detected by atomic absorption assay. In 2 of 3 patients given 100 mg of CDDP into the pleural cavity, the active form of CDDP was detected in sera. High-dose CDDP administration was concluded to be preferable to low-dose therapy because of the higher peak concentration and longer residence time of the active form of CDDP in the plasma. Furthermore, it is suggested that a systemic effect of CDDP can be expected even when CDDP is given by intrapleural administration.

Adult↗
PubMed1985

Detection of NK activity and antibody-dependent cellular cytotoxicity of lymphocytes by human tumor clonogenic assay--its correlation with the 51Cr-release assay.

NK activity of human peripheral blood lymphocytes (PBL) for cells of the human myeloid line K562, and antibody-dependent cellular cytotoxicity (ADCC) of PBL for cells of human lung adenocarcinoma line PC-9 were determined by the human tumor clonogenic assay (HTCA). Incubation of K562 cells or anti-PC-9 serum treated PC-9 cells with PBL before plating inhibited the formation of colonies of these tumor cells. The percent inhibition of tumor cell colony formation was dependent on the effector/target ratio, the incubation time before plating and, in the case of PC-9 cells, on the dilution of anti-PC-9 serum. PBL activated with human T-cell growth factor (TCGF), lymphokine-activated killer (LAK) cells, significantly augmented the inhibition of colony formation of K562 cells, compared to the control lymphocytes. The increase in colony inhibition was dependent on the concentration of TCGF and the time of incubation of PBL with TCGF. The HTCA determining the colony inhibition of K562 cells incubated with LAK or PBL correlated with the 51Cr-release assay (p less than 0.001). The HTCA determining the colony inhibition of anti-PC-9 serum-treated PC-9 cells incubated with PBL also correlated with the 51Cr-release assay (p less than 0.001). We found that the NK activity and ADCC of lymphocytes on K562 and PC9 tumor lines could be detected with HTCA.

Adenocarcinoma↗
PubMed1985

Evaluation of a new drug 7-N-(p-hydroxyphenyl)-mitomycin C [KW 2083] against carcinoma of the lung by the human tumor clonogenic assay.

KW 2083, which is a new mitomycin C derivative currently under clinical investigation, was tested for its antitumor effect on the growth of human carcinoma of the lung by using an in vitro clonogenic assay system. The in vitro results in this study were as follows: We succeeded in producing clonal growth at a high rate in all histologic types of carcinoma of the lung in the assay system. That is, 61 of 81 specimens (75%) of either primary or metastatic tumors gave adequate growth for chemosensitivity testing. The in vitro responses to vindesine, adriamycin, mitomycin C and melphalan (substituted for cyclophosphamide in vitro), as standard anticancer drugs for chemotherapy of carcinoma of the lung were 18, 23, 18 and 19%, respectively, which are in good general agreement with the clinical responses to these drugs reported previously. Therefore, the clonogenic assay system might prove to be a very effective tool for an in vitro phase II study of new drugs. The rate of response to KW 2083 tested simultaneously in 51 cancer specimens was 22%, which was superior to that of mitomycin C. These results indicate that KW 2083 might be more useful than mitomycin C in clinical practice.

Adenocarcinoma↗
PubMed1985

Time-schedule dependency of the inhibiting activity of various anticancer drugs in the clonogenic assay.

To analyze the discrepancy between the in vitro response in the clonogenic assay and the clinical response, the time-schedule dependencies of various anticancer drugs were determined by comparing the inhibiting effect against colony formation by PC-7 cells treated with the drugs for 1 h with that of those treated for 24 h. According to their schedule dependency the drugs can be divided into a schedule-dependent drug group (5-fluorouracil, methotrexate, bleomycin, pepleomycin, etoposide, cisplatin, teniposide, vindesine, and vinblastine) and a non-schedule-dependent drug group (adriamycin, actinomycin D, ranomustine, mitomycin C, aclacinomycin, daunomycin, nimustine, melphalan, and KW 2083). In the clonogenic assay, the 1-h exposure schedule is appropriate for predicting clinical response for the non-schedule-dependent drugs. However, the effect of the schedule-dependent drugs was underestimated in the same conditions. Therefore, it is necessary to test these drugs in the assay by 24-h exposure for a more accurate assessment of their antitumor activity.

Adenocarcinoma↗
PubMed1985

The use of human tumor clonogenic assay in predicting combination effect of cisplatin plus vindesine in carcinoma of the lung.

By using a human tumor clonogenic assay, cisplatin plus vindesine regimen was evaluated in 17 carcinoma of the lung. The cisplatin (0.2 microgram/ml) plus vindesine (0.005 microgram/ml) combination was synergistic and additive cell killing in 10 and 4, respectively, of 17 specimens. On the other hand, only three specimens showed antagonistic cell killing from this drug combination. Our results indicated that this in vitro assay provides a new method which can predict the effects of the combination of drugs on individual patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

[Update of human tumor clonogenic assay in carcinoma of the lung].

The human tumor clonogenic assay (HTCA) is a double-layer agar technique, which provides an in vitro prediction of the response of an individual patient's tumor to an antitumor agent. This paper briefly provides an outline of HTCA and its potential use in chemotherapy on patients with lung cancer. In our experience with culturing 123 carcinomas of the lung, 105 specimens (85%) could be subject to more than 5 chemosensitivity tests each by modifying the preparation method of single cell suspension in this system. Growth rate was improved in all types of primary human lung cancer with reasonable consistency. Further, metastatic tumors were capable of being successfully grown in a high percentage of cases, which was comparable to the results obtained for other kinds of tumors. There was no correlation of growth or cloning efficiency with histology, source, or previous chemotherapy. Using 50% or more inhibition on to colony formation as the criterion for chemosensitivity, response rates to vindesine or mitomycin C were 19% or 16%, respectively. The in vitro response rates of these or almost all other antitumor drugs seemed to be comparable to the clinical responses reported by various investigators. Correlation between in vitro chemosensitivity in HTCA and clinical response has been evaluated by various investigators, and the pooled data have demonstrated a good association between in vitro drug sensitivity and clinical response or lack of response. In lung cancer, HTCA had a 57% true positive rate and an 85% true negative rate for the prediction of drug sensitivity and resistance, respectively, of cancer patients to specific chemotherapeutic drugs. Although the system still has to undergo modification to resolve a number of theoretical and practical problems, it has potential uses in lung cancer chemotherapy.

Adenocarcinoma↗