3'-Deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin conquers multidrug resistance by rapid influx following higher frequency of formation of DNA single- and double-strand breaks.

The mechanism of action of 3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin (MX2) was examined in a human leukemia cell line (K562) and its Adriamycin (ADM)-resistant subline (K562/ADM). ADM and MX2 showed an equivalent antitumor effect against K562. K562/ADM was highly resistant to ADM. In cellular pharmacokinetic studies, MX2 showed faster and greater influx than did ADM in both K562 and K562/ADM. The efflux of ADM was rapid in K562/ADM but not in K562. On the other hand, the efflux of MX2 was rapid in both cell lines. The formation of DNA single-strand breaks and double-strand breaks by ADM was significantly lower in K562/ADM than K562. On the other hand, formation of those breaks by MX2 was not decreased. Although some of the DNA breaks induced by MX2 were resealed, there was no difference in the degree of resealing in K562 and K562/ADM cells. On the other hand, most of the small number of DNA breaks in K562/ADM induced by ADM were resealed. The topoisomerase II activity in K562 and K562/ADM was not significantly different. It is concluded that MX2 conquers multidrug resistance by rapid influx following a higher frequency of formation of DNA single- and double-strand breaks in K562/ADM cells.

In vitro evaluation of the new anticancer agents KT6149, MX-2, SM5887, menogaril, and liblomycin using cisplatin- or adriamycin-resistant human cancer cell lines.

A new model to predict antitumor activity of new analogues was developed, and the cross-resistance against cisplatin (CDDP) and Adriamycin (ADM) was examined. A preclinical evaluation of various new analogues using this new model was performed. The antitumor activities of KT6149, MX-2 (KRN8602), SM5887, menogaril (TUT-7), and liblomycin (NK313) were evaluated against four non-small cell lung cancer cell lines, PC-7, -9, -13, and -14; two small cell lung cancer cell lines, H69 and N231; four CDDP-resistant cell lines, PC-7/1.0, PC-9/0.5, PC-14/1.5, and H69/0.4; a human myelogenous leukemia cell line, K562; and its ADM-resistant subline, K562/ADM by clonogenic assay. The relative antitumor activities of these new analogues were compared with those of parental agents, mitomycin C, ADM, bleomycin, and several anticancer drugs, CDDP, daunomycin, vindesine, and etoposide. KT6149 was more active than mitomycin C against all lung cancer cell lines and the human myelogenous leukemia cell line. Menogaril showed greater activity than ADM, and MX-2 showed activity similar to ADM. However, the antitumor activity of SM5887 was lower than that of ADM. SM5887 and menogaril showed cross-resistance to K562/ADM. Nevertheless, the antitumor activity against K562/ADM of MX-2 was similar to that of the parental cell lines. The activity of liblomycin was similar to that of bleomycin. Thus, KT6149 appears to be the best analogue for use in a clinical trial against lung cancer. MX-2 was active even against ADM-resistant cancer cells. The values of relative resistance to CDDP or ADM were 4.7, 8.1, 7.5, 20.0, and 13.6 for PC-7/1.0, PC-9/0.5, PC-14/1.5, H69/0.4, and K562/ADM, respectively. CDDP-resistant cell lines showed no cross-resistance with other drugs in this study. K562/ADM showed cross-resistance against daunomycin, etoposide, and vindesine. In contrast, mitomycin C and bleomycin had nearly equal activity against K562 and K562/ADM. However, K562/ADM was 2.4-fold more sensitive to CDDP than its parental cell line, K562 (P less than 0.001). These results suggested that the mechanism of CDDP resistance is different from that of multidrug resistance.

Pharmacokinetics of (glycolate-0,0')-diammine platinum (II), a new platinum derivative, in comparison with cisplatin and carboplatin.

The pharmacokinetics of (glycolato-0,0')-diammine platinum (II) (254-S; NSC 375101D), one of the new platinum analogues, was examined in a phase I study of this drug and compared with that of cisplatin and carboplatin. All drugs were given in short-term (30-min) i.v. drip infusions; the doses of 254-S, cisplatin, and carboplatin were 100, 80, and 450 mg/m2, respectively. Platinum concentrations in whole plasma, plasma ultrafiltrate, and urine were determined by atomic absorption spectrometry. After the infusion, the plasma concentration of total platinum for the three agents decayed biphasically. Ultrafilterable platinum in plasma decreased in a biexponential mode after infusions of 254-S and carboplatin, whereas the free platinum of cisplatin showed a monoexponential disappearance. The peak plasma concentrations and AUC for free platinum were 5.31 micrograms/ml and 959 micrograms/min per ml for 254-S, 3.09 micrograms/ml and 208 micrograms/min per ml for cisplatin, and 19.90 micrograms/ml and 3446 micrograms/min per ml for carboplatin, respectively. The mean ratio of plasma ultrafilterable platinum to total platinum were calculated, and the results showed that the protein-binding abilities of 254-S and carboplatin were almost identical. More than 50% of the 254-S was excreted in the urine within the first 480 min after its administration. Thrombocytopenia was reported as a dose-limiting toxicity for both 254-S and carboplatin. This similarity in side effects may mainly be due to the comparable pharmacokinetic behavior of these two platinum compounds.

Vinca alkaloids induce granulocyte-macrophage colony stimulating factor in human peripheral blood mononuclear cells.

Several anti-cancer drugs are known to have proliferation-related effects on various cells, such as an activation of some transcription factors and an induction of some cytokines. We examined the effect of anti-cancer drugs on granulocyte-macrophage colony stimulating factor (GM-CSF) induction in human peripheral blood mononuclear cells (PBMC). Increase of GM-CSF protein and mRNA were observed in PBMC after exposure to vindesine sulfate (VDS). Induction of GM-CSF protein was dose-dependent and detectable at VDS concentrations of 0.1 microgram/ml. This effect was also observed in response to treatment with other microtuble-depolymerizing agents, vincristine sulfate and vinorelbine ditartrate, but not with cisplatin, etoposide, or paclitaxel. In order to elucidate the mechanism of this phenomenon, we examined the effects of cyclohexamide and actinomycin D on the expression of GM-CSF mRNA. Both of these drugs completely inhibited GM-CSF mRNA expression after VDS exposure, implying that VDS induces de novo GM-CSF synthesis in an indirect manner. As a candidate for the initial signaling, we next examined the role of the IL-1 beta autocrine or paracrine pathways in GM-CSF induction by VDS. IL-1 beta protein and mRNA expression were induced after VDS exposure more rapidly (from 4 hours) than expression of GM-CSF (protein from 12 hours and mRNA from 8 hours). Addition of anti-IL-1 beta antibody partially inhibited induction of GM-CSF by VDS. These results suggest that GM-CSF induction by VDS is partially mediated through the initial generation of IL-1 beta in PBMC.

[Examination on efficacy and safety of concurrent use of ondansetron hydrochloride and steroid in lung cancer patients on cisplatin].

The anti-emetic effect and safety in patients receiving ondansetron hydrochloride (OND group) and concurrent use of ondansetron and dexamethasone (DEX group) in cases of acute and delayed onset emesis induced by a single high dose of cisplatin, given as a chemotherapy to lung cancer patients, were comparatively studied. The study subjects were 78 lung cancer patients. The OND group received 4 mg of ondansetron via slow intravenous injection on Day 1, 30 minutes prior to cisplatin, and for Days 2 to 5, the subjects orally received 4 mg ondansetron tablet each day. The DEX group received the same dose regimen of ondansetron as the OND group for Days 1-5, but in addition the subjects received dexamethasone injection in doses of 8 mg twice daily on Day 1 and 4 mg (1 mg QID) daily for Days 2-5. An anti-emetic effect against acute nausea and vomiting was achieved in 83.8% of the OND group and in a higher rate of 94.6% of the DEX group. Significantly better efficacy was seen in the DEX group as to the complete suppression rate of nausea and vomiting and the improvement of food intake. The group also achieved better efficacy in delayed onset of emesis. Two cases of adverse reactions (hiccups and elevation of ALT and BUN) were observed in the DEX group; however, since the symptoms were all mild, we did not consider there was any problem in safety. We conclude from the above findings that concurrent administration of ondansetron hydrochloride and dexamethasone is a clinically useful treatment for acute and delayed onset emesis induced by a single high dose of cisplatin given to lung cancer patients.

Altered expression of topoisomerase IIalpha contributes to cross-resistant to etoposide K562/MX2 cell line by aberrant methylation.

KRN 8602 (MX2) is a novel morpholino anthracycline derivative having the chemical structure 3'-deamino-3'-morpholino-13-deoxo-10-hydroxycarminomycin hydrochloride. To investigate the mechanisms of resistance to MX2, we established an MX2-resistant phenotype (K562/MX2) of the human myelogeneous leukaemia cell line (K562/P), by continuously exposing a suspension culture to increasing concentrations of MX2. K562/MX2 cells were more resistant to MX2 than the parent cells, and also showed cross-resistance to etoposide and doxorubicin. Topoisomerase (Topo) IIalpha protein levels in K562/MX2 cells were lower of those in K562/P cells on immunoblot analysis and decreased expression of Topo IIalpha mRNA was seen in K562/MX2 cells. Topoisomerase II catalytic activity was also reduced in the nuclear extracts from K562/MX2 cells when compared with K562/P cells. Aberrant methylated CpG of Topo IIalpha gene was observed in K562/MX2 cells when compared with the parent line on methylation-specific restriction enzyme analysis. To overcome the drug resistance to MX2 and etoposide, we investigated treatment with 5-Aza-2'-deoxycytidine (5AZ), which is a demethylating agent, in K562/MX2 cells. 5-Aza-2'-deoxycytidine treatment increased Topo IIalpha mRNA expression in K562/MX2 cells, but not in K562/P cells, and increased the cytotoxicity of MX2 and etoposide. Methylated CpG was decreased in K562/MX2 cells after 5AZ treatment. We concluded that the mechanism of drug resistance to MX2 and etoposide in K562/MX2 cells might be the combination of decreased expression of Topo IIalpha gene and increased methylation, and that 5AZ could prove to be a novel treatment for etoposide-resistant cell lines, such as K562/MX2.

Can cytotoxic activity of anthracyclines be related to DNA damage?

Accumulation, cytotoxicity, and DNA damages produced by doxorubicin (DOX), pirarubicin (THP-DOX), fluoro-doxorubicin (ME2303) or its isolated metabolite M1 have been investigated in human myelogenous leukemia cells, sensitive (K562) and resistant to DOX (K562/DOX). These compounds differed by lipophilicity and/or sugar moiety either with (DOX, THP-DOX) or without (ME2303, M1) amino group. In K562 cells, the cytotoxicity was correlated to DNA single-stranded breaks and the intracellular drug amount of DOX or M1. This was not true when the cells were treated with THP-DOX or ME2303. In addition, THP-DOX produced total DNA protein cross-linking. In K562 cells DNA damage was not repaired, while in K562/DOX repair of DNA damage produced by all drugs could be observed. Although in K562/DOX cells drug accumulation was much reduced, higher intracellular drug concentration was required to induce similar level of cytotoxicity and DNA damage. Thus, cytotoxicity produced by anthracycline is not always associated with DNA damage. Different level of resistance to DOX, THP-DOX, ME2303 or M1 is associated with reduced drug accumulation which varies with the structure.

[Informed consent of the family in the chemotherapy for lung cancer].

In Japan where the question of cancer notification has yet to be resolved, it is difficult to obtain an informed consent from the patient himself in clinical studies of the chemotherapies for cancer. In fact, the chemotherapy is administered while not enough explanation is given to the family let alone the patient. Such is the present situation. For the purpose of finding out the best possible method at present, we carried out a method whereby an informed consent of the family is substituted for a consent of the patient in phase II study of inoperable non-small cell carcinoma of the lung. As a result, the consent was obtained from 21 (91.3%) out of 23 families. This method should be taken into consideration as a feasible one under the present circumstances. It was in only one family (4.3%) that a consent on the notification of diagnosis from the family to the patient was obtained. In order for the informed consent to be established, efforts to form a social consensus on cancer notification are needed.

[Three patients with spontaneous pneumomediastinum, including one in whom pneumomediastinum recurred].

We encountered three patients with spontaneous pneumomediastinum. All three (two men and one woman) were previously healthy. They complained of chest pain or dyspnea. On admission, physical examination revealed subcutaneous emphysema. Chest roentgenograms and computed tomograms revealed pneumomediastinum and subcutaneous emphysema. All other findings were normal. All patients were treated with bed rest and all recovered in 7 to 9 days. Pneumomediastinum recurred in one patient after 20 months.