Knockouts of TUT7 and 3'hExo show that they cooperate in histone mRNA maintenance and degradation.

Metazoan histone mRNAs are the only cellular eukaryotic mRNAs that are not polyadenylated, ending instead in a conserved stem-loop. SLBP is bound to the 3' end of histone mRNAs and is required for translation of histone mRNA. The expression of histone mRNAs is tightly cell-cycle regulated. A major regulatory step is rapid degradation of histone mRNA at the end of S-phase or when DNA synthesis is inhibited in S-phase. 3'hExo, a 3' to 5' exonuclease, binds to the SLBP/SL complex and trims histone mRNA to 3 nt after the stem-loop. Together with a terminal uridyl transferase, 3'hExo maintains the length of the histone mRNA during S-phase. 3'hExo is essential for initiating histone mRNA degradation on polyribosomes, initiating degradation into the 3' side of the stem-loop. There is extensive uridylation of degradation intermediates in the 3' side of the stem when histone mRNA is degraded. Here, we knocked out TUT7 and 3'hExo and we show that both modification of histone mRNA during S-phase and degradation of histone mRNA involve the interaction of 3'hExo, and a specific TUTase, TENT3B (TUT7, ZCCHC6). Knockout of 3'hExo prevents the initiation of 3' to 5' degradation, stabilizing histone mRNA, whereas knockout of TUT7 prevents uridylation of the mRNA degradation intermediates, slowing the rate of degradation. In synchronized 3'hExo KO cells, histone mRNA degradation is delayed, but the histone mRNA is degraded prior to mitosis by a different pathway.

Automatic Registration of Homogeneous and Cross-Source TomoSAR Point Clouds in Urban Areas.

Building reconstruction using high-resolution satellite-based synthetic SAR tomography (TomoSAR) is of great importance in urban planning and city modeling applications. However, since the imaging mode of SAR is side-by-side, the TomoSAR point cloud of a single orbit cannot achieve a complete observation of buildings. It is difficult for existing methods to extract the same features, as well as to use the overlap rate to achieve the alignment of the homologous TomoSAR point cloud and the cross-source TomoSAR point cloud. Therefore, this paper proposes a robust alignment method for TomoSAR point clouds in urban areas. First, noise points and outlier points are filtered by statistical filtering, and density of projection point (DoPP)-based projection is used to extract TomoSAR building point clouds and obtain the facade points for subsequent calculations based on density clustering. Subsequently, coarse alignment of source and target point clouds was performed using principal component analysis (PCA). Lastly, the rotation and translation coefficients were calculated using the angle of the normal vector of the opposite facade of the building and the distance of the outer end of the facade projection. The experimental results verify the feasibility and robustness of the proposed method. For the homologous TomoSAR point cloud, the experimental results show that the average rotation error of the proposed method was less than 0.1°, and the average translation error was less than 0.25 m. The alignment accuracy of the cross-source TomoSAR point cloud was evaluated for the defined angle and distance, whose values were less than 0.2° and 0.25 m.

Joint Sparsity for TomoSAR Imaging in Urban Areas Using Building POI and TerraSAR-X Staring Spotlight Data.

Synthetic aperture radar (SAR) tomography (TomoSAR) can obtain 3D imaging models of observed urban areas and can also discriminate different scatters in an azimuth-range pixel unit. Recently, compressive sensing (CS) has been applied to TomoSAR imaging with the use of very-high-resolution (VHR) SAR images delivered by modern SAR systems, such as TerraSAR-X and TanDEM-X. Compared with the traditional Fourier transform and spectrum estimation methods, using sparse information for TomoSAR imaging can obtain super-resolution power and robustness and is only minorly impacted by the sidelobe effect. However, due to the tight control of SAR satellite orbit, the number of acquisitions is usually too low to form a synthetic aperture in the elevation direction, and the baseline distribution of acquisitions is also uneven. In addition, artificial outliers may easily be generated in later TomoSAR processing, leading to a poor mapping product. Focusing on these problems, by synthesizing the opinions of various experts and scholarly works, this paper briefly reviews the research status of sparse TomoSAR imaging. Then, a joint sparse imaging algorithm, based on the building points of interest (POIs) and maximum likelihood estimation, is proposed to reduce the number of acquisitions required and reject the scatterer outliers. Moreover, we adopted the proposed novel workflow in the TerraSAR-X datasets in staring spotlight (ST) work mode. The experiments on simulation data and TerraSAR-X data stacks not only indicated the effectiveness of the proposed approach, but also proved the great potential of producing a high-precision dense point cloud from staring spotlight (ST) data.

Underlying Topography Inversion Using Dual Polarimetric TomoSAR.

Underlying topography plays an important role in the national economic construction, military security, resource exploration and investigation. Since synthetic aperture radar tomography (TomoSAR) can achieve the three-dimensional imaging of forests, it has been widely used in underlying topography estimation. At present, there are two kinds of TomoSAR based on the applied datasets: single polarimetric TomoSAR (SP-TomoSAR) and fully polarimetric TomoSAR (FP-TomoSAR). However, SP-TomoSAR cannot obtain the underlying topography accurately due to the lack of enough observations. FP-TomoSAR can improve the estimation accuracy of underlying topography. However, it requires high-cost data acquisition for the large-scale application. Thus, this paper proposes the dual polarimetric TomoSAR (DP-TomoSAR) as another suitable candidate to estimate the underlying topography because of its wide swath and multiple polarimetric observations. Moreover, three frequently used spectral estimation algorithms, namely, Beamforming, Capon and MUSIC, are used in DP-TomoSAR. For validation, a series of simulated experiments was carried out, and the airborne P-band multiple polarimetric SAR data over the Lope, Gabon was also acquired to estimate the underlying topography. The results suggest that DP-TomoSAR in HH & HV combination is more suitable to estimate underlying topography over forest areas than other DP combinations. Moreover, the estimation accuracy of DP-TomoSAR is slightly lower than that of FP-TomoSAR but is higher than that of SP-TomoSAR.

The Uridylyl Transferase TUT7-Mediated Accumulation of Exosomal miR-1246 Reprograms TAMs to Support CRC Progression.

Tumor-associated macrophages (TAMs) play a crucial role in promoting tumor growth and dissemination, motivating a search for key targets to interfere with the activation of TAMs or reprogram TAMs into the tumor-suppressive type. To gain insight into the mechanisms of macrophage polarization, a designed co-culture system is established, allowing for the education of macrophages in a manner that closely mimics the intricacies of TAMs in the tumor immune microenvironment (TIME). Through database mining, exosomal miR-1246 is identified and is then validated. Exosomal miR-1246-driven polarization of TAMs disrupts the infiltration and function of CD8+ T cells. Mechanically, the amassment of exosomal miR-1246 stems from TUT7-mediated degradation of small noncoding RNA, a process stabilized by SNRPB, but not the precursor of miR-1246. Moreover, an Exo-motif is present in the exosomal miR-1246 sequence, enabling it to bind with the exosomal sorting protein hnRNPA2B1. RNA-seq analysis reveals that exogenous miR-1246 modulates the polarization of TAMs at a post-transcriptional level, emphasizing the pivotal role of the NLRP3 in macrophage polarization. In conclusion, the findings underscore the importance of exosomal miR-1246 as a trigger of macrophage reprogramming and uncover a novel mechanism for its enhanced presence in the TIME.

Phase II study of intravenous menogaril in patients with advanced breast cancer.

Menogaril was administered to 40 patients with advanced breast cancer who had not received anthracycline drugs previously. The drug was given iv as a 2-hour infusion, repeated every 4 weeks, at doses of 200 mg/m2 and 160 mg/m2 in good-risk and poor-risk patients. The overall response rate was 22% in patients with no prior chemotherapy and 10% in patients previously exposed to chemotherapy. Leukopenia was generally moderate and predictable. Phlebitis and erythema along the vein injected occurred in 34% and 17% of the cases, respectively. Menogaril is an active drug used in the treatment of patients with advanced breast cancer who have not had prior systemic therapy.

Justification for evaluating new anticancer drugs in selected untreated patients with extensive-stage small-cell lung cancer: an Eastern Cooperative Oncology Group randomized study.

BACKGROUND: Studies have shown that response to a given chemotherapy in previously untreated patients with extensive-stage small-cell lung cancer is superior to that in patients previously treated with other regimens. This finding raises the question of whether it is necessary and ethical to study the effects of new anticancer agents in untreated patients. Such studies appear to be the best test for drug development, but there has been no evaluation of whether survival of untreated patients, whose cancer is sensitive to established drugs, is adversely affected in trials of new drugs. PURPOSE: This randomized study of untreated patients with extensive-stage small-cell lung cancer was designed (a) to compare the survival of patients treated with either effective standard chemotherapy or an investigational anticancer drug as initial therapy and (b) to evaluate response rates and toxic effects of such therapies. METHODS: Eighty-six patients were randomly assigned to receive, as initial therapy, either the standard CAV regimen--cyclophosphamide (1000 mg/m2), doxorubicin (50 mg/m2), and vincristine (1.4 mg/m2) every 3 weeks--or the phase II drug menogaril (200 mg/m2) every 4 weeks. Treatment after induction therapy varied, depending on patient response, but nonresponders and those with disease progression received salvage chemotherapy--etoposide (120 mg/m2 on days 1, 2, and 3) and cisplatin (60 mg/m2 on day 1), repeated every 3 weeks. RESULTS: Of the 43 patients on CAV, 42% responded (eight complete responses and 10 partial responses); 5% of the 43 on menogaril responded (two partial responses) (P = .0001). Twelve (22%) of 54 patients responded to salvage chemotherapy (five complete responses and seven partial responses). Within 3 months from start of treatment, twelve patients died--3 patients in the CAV group and nine patients in the menogaril group (P = .12). The estimated median survival was 37 weeks with menogaril and 45 weeks with CAV (P = .28). At 6 months, survival was 76.7% for the CAV group and 67.4% for the menogaril group. At 12 months, survival rates were 24.4% and 27.9%, respectively. Confidence intervals (95%) for the differences between the proportions surviving in the two groups were -9%-28% at 6 months and -25%-14% at 12 months. Use of CAV resulted in significantly higher occurrence of severe and life-threatening treatment-related complications (P = .002). CONCLUSION: The confidence intervals for the differences in survival are too wide to conclude that evaluation of a new drug in untreated patients with extensive-stage small-cell lung cancer is or is not harmful. The data do suggest, however, that use of this study design may have no adverse effect on survival.

Pharmacokinetics and systemic bioavailability of menogaril, an anthracycline antitumor agent, in the mouse, dog, and monkey.

Menogaril is an antitumor agent of the anthracycline type which is less cardiotoxic than doxorubicin in a chronic rabbit model and is active in experimental tumor systems when given by p.o. or parenteral routes. It is currently undergoing i.v. and p.o. Phase II clinical evaluation. We report here the results of pharmacokinetic and systemic bioavailability studies of menogaril in three species (mouse, dog, and monkey). Upon i.v. administration, menogaril plasma concentration-time curves declined in a biexponential (dog) or triexponential (mouse and monkey) manner, with the terminal disposition half-life (t1/2) being considerably shorter in the dog (2.86 +/- 0.47 h) than in the mouse and monkey (21.6 and 19.0 +/- 3.7 h, respectively). The systemic clearance (CL, in liters/h/kg) was highest in mouse (6.2), followed by dog (2.9) and then monkey (1.4). The drug was extensively distributed in all three species, with steady state volumes of distribution being 88.5, 9.8, and 27.9 liters/kg in the mouse, dog, and monkey, respectively. One, two, and three metabolites were detected in the plasma of mice, monkeys, and dogs, respectively, using reverse phase high performance liquid chromatography. The major fluorescent metabolite in all species coeluted with authentic N-demethyl-menogaril; the other two metabolites were present at low concentrations relative to unchanged menogaril and its putative N-demethylated metabolite. One of these metabolites, which was found in both the dog and monkey, eluted with authentic (7R)-nogarol. Mean maximum plasma concentrations of the putative N-demethylmenogaril metabolite were approximately one-tenth those of menogaril in all three species following i.v. drug administration. Upon p.o. treatment, first-pass metabolism or incomplete absorption reduced the systemic bioavailability to 12% in the dog and 33% in the mouse and monkey. N-Demethylmenogaril was the major fluorescent metabolite observed in the plasma of p.o. treated animals. Interspecies comparison of menogaril pharmacokinetic parameters in mice, dogs, monkeys, and humans using allometric techniques indicated that the parameters for mice, monkeys, and humans were highly correlated; in each of these species presystemic metabolism of p.o. administered menogaril reduced its systemic bioavailability to an equivalent extent (30-35%). To determine if metabolically formed N-demethylmenogaril might contribute to the overall antitumor activity of menogaril, we determined the effect of synthetic N-demethylmenogaril on the life span of mice bearing P388 leukemia. Results indicated that the metabolite is marginally active compared to menogaril itself.

Metabolism and disposition of menogaril (NSC 269148) in the rabbit.

We have investigated the metabolism and disposition, in rabbits, of menogaril (7-OMEN), a new anthracycline antibiotic recently introduced into clinical trials. 7-OMEN was administered by rapid i.v. injection at a dosage of 2.5 mg/kg. 7-OMEN and metabolites were assayed by high performance liquid chromatography. Plasma concentrations of 7-OMEN declined in biexponential fashion with a terminal half-life of 2.7 h. The area under the plasma concentration versus time curve was 1.3 microM X h. The systemic clearance of 7-OMEN was 57.6 ml/min/kg. No metabolite of 7-OMEN was detected in plasma. At 8 h after treatment, the cumulative urinary and biliary excretions of 7-OMEN equivalents amounted to 1.3 and 3.4% of the total administered dose, respectively. 7-OMEN was the predominant fluorescent compound in urine, but four metabolites were also seen. In bile, 7-OMEN represented only 9.6% of the cumulative excretion and six metabolites were observed. Among the organs, lungs contained the highest concentrations of parent drug. Substantial concentrations of metabolites were observed in the kidneys, liver, duodenum, and small intestine. Three of the observed metabolites of 7-OMEN have been tentatively identified as N-demethylmenogaril, 7-deoxynogarol, and N-demethyl-7-deoxynogarol.

Phase I study and pharmacokinetics of menogaril (NSC 269148) in patients with hepatic dysfunction.

We performed a phase I study of menogaril to determine if dosage reduction was required in patients with hepatic dysfunction and if the relationship between pharmacokinetics and leukopenia, previously defined in patients with normal hepatic and renal function, was altered. Eighteen patients received 27 courses of menogaril, of which 26 were evaluable for toxicity. Patient characteristics were median age, 63 years (range, 28-80 years), 14 male/4 female, and median Karnofsky performance status 80% (range, 60-100%). Prior therapy included none, five; chemotherapy only, seven; radiotherapy only, two; and chemotherapy and radiotherapy, four. Menogaril was administered as a 2-h.i.v. infusion every 28 days at 62.5 (one patient), 125 (eight patients), 187.5 (seven patients), and 250 mg/m2 (six patients), based on pretreatment serum bilirubin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Patients also had indocyanine green and antipyrine clearances measured before menogaril treatment. Menogaril and metabolites were assayed by high performance liquid chromatography. Dose-limiting toxicity was leukopenia. WBC nadirs occurred between days 8 and 20 (median, 15). Three patients developed platelet nadirs below 100,000/microliters. Other toxicities included grade I nausea and vomiting in three patients and phlebitis at the site of drug infusion in six patients. Correlations were defined between pretreatment indocyanine green clearance and serum concentrations of alkaline phosphatase and total bilirubin. There were no correlations between pretreatment serum concentrations of bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, indocyanine green clearance or antipyrine and menogaril clearances. Menogaril pharmacokinetics in patients with elevated liver function tests was indistinguishable from that described in patients with normal liver function tests. There were excellent correlations between plasma area under the curve of menogaril and the percentage decreases in WBC and neutrophils. These were well described by two models previously used to study the same relationships in patients with normal hepatic and renal function. When compared to previous studies, patients with hepatic and renal dysfunction had a greater percentage decrease in WBC for any given area under the curve than did patients with normal hepatic and renal function. On the other hand, there was no difference in the relationship between percentage decrease in neutrophils and menogaril area under the curve in these two groups of patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Human pharmacokinetics, excretion, and metabolism of the anthracycline antibiotic menogaril (7-OMEN, NSC 269148) and their correlation with clinical toxicities.

In a Phase I study, menogaril (7-OMEN) was administered daily for 5 days/course, every 21-28 days. Dosages of 3.5, 7, 11.5, 17, and 31.5 mg/m2 were infused over 1 h, and dosages of 42, 50, and 56 mg/m2 were infused over 2 h. Pharmacokinetics was studied at all dosages. Plasma and urine samples were collected from 24 patients, and bile samples were also collected from 2 patients. 7-OMEN and metabolites were measured by high performance liquid chromatography. 7-OMEN was the major plasma fluorescent species at all times, with only trace amounts of N-demethyl menogaril observed. 7-OMEN disappeared from plasma biexponentially with t1/2 alpha 0.19 +/- 0.04 (mean +/- SE) h and t1/2 beta 13.22 +/- 1.54 h. Plasma pharmacokinetics of 7-OMEN was linear from 3.5-56 mg/m2; area under the curve increased proportionally with dosage. Total body clearance of 7-OMEN was 28.18 +/- 3.33 liter/m2/h, Vc was 224 +/- 30.8 liter/m2, and Vss was 370 +/- 25.7 liter/m2. Plasma pharmacokinetics of 7-OMEN studied on multiple days of a given course were similar. Urinary excretion of 7-OMEN and fluorescent metabolites accounted for 5.4 +/- 0.4% of the daily dose. Parent compound still represented greater than or equal to 80% of urinary drug fluorescence after 24 h. N-demethyl menogaril was the only other fluorescent drug species detected in urine. In two patients with biliary tract drains, biliary excretion of drug fluorescence accounted for 2.2-4.2% of the daily dose. Only 7-OMEN and N-demethyl menogaril were detected in bile by high performance liquid chromatography and thin layer chromatography. 7-OMEN was the major fluorescent biliary species, but, by 24 h, N-demethyl menogaril accounted for approximately 40% of biliary drug fluorescence. When considered in light of each patient's observed toxicities, excellent relationships were observed between the plasma area under the curve of 7-OMEN and the percentage of decreases in WBC and absolute neutrophil count. These latter findings should be useful in developing more precise and intelligent dosing schemes for 7-OMEN.

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.

Effect of 7-con-O-methylnogarol on DNA synthesis, survival, and cell cycle progression of Chinese hamster ovary cells.

The effect of 7-con-O-methylnogarol (7-OMEN) on the survival of exponentially growing and plateau-phase Chinese hamster ovary cells was determined in a cloning assay. After 2 hr of exposure, the 50% lethal dose for exponential and plateau-phase cells was 0.3 and 1.5 microgram/ml, respectively. Drug doses for cell progression studies were based upon drug lethality; therefore, higher doses were used for plateau than for exponential populations. The effect of 7-OMEN on cell progression was studied by DNA flow cytometry under the following conditions: (a) during 24 hr of continuous exposure of exponentially growing cells; (b) during recovery of exponential cells after 2 or 7 hr of drug exposure; and (c) during recovery of plateau-phase cells after 2 hr of exposure. Exponential cells exposed continuously for 24 hr progressed normally from M to G1 phase and from G1 to S phase, progression through S phase was slowed, and cells were ultimately blocked in G2 + M. Inhibition of S-phase progression was dose dependent, 0.2 microgram/ml having only slight effect and 1.0 microgram/ml accumulating a large fraction in S phase. Inhibition of S-phase progression correlated with DNA synthesis inhibition. Similar inhibitory effects were observed after pulsed (2- or 7-hr) exposure of exponential cells. 7-OMEN also blocked plateau-phase cells in G2 + M after 2 hr of exposure, but higher doses (3.0 microgram/ml) were required. Simultaneous exposure of exponential cells to Colcemid (which blocks cells in metaphase) and 1.0 microgram 7-OMEN per ml completely inhibited the expected increase in mitotic index, indicating that the G2 + M block observed by DNA flow cytometry was a block in G2 or prophase.

Comparative genotoxicity of adriamycin and menogarol, two anthracycline antitumor agents.

Adriamycin and menogarol are anthracyclines which cause more than 100% increase in life span of mice bearing P388 leukemia and B16 melanoma. Unlike Adriamycin, menogarol does not bind strongly to DNA, and it minimally inhibits DNA and RNA synthesis at lethal doses. Adriamycin is a clinically active drug, and menogarol is undergoing preclinical toxicology at National Cancer Institute. In view of the reported mutagenicity of Adriamycin, we have compared the genotoxicity of the two drugs. Our results show that, although Adriamycin and menogarol differ significantly in their bacterial mutagenicity (Ames assay), they have similar genotoxic activity in several mammalian systems. Adriamycin is strongly mutagenic in the Ames assay with TA98 and TA100. Menogarol is nonmutagenic to TA98 and TA100. For the mammalian cell culture systems, V79 (Chinese hamster) cells are exposed for 2 hr to drug, following which cell survival, induction of sister chromatid exchanges, chromosome damage, and production of mutants resistant to 6-thioguanine are measured. The percentage of survival obtained with the two drugs ranges between 25 and 50% at 0.15 microgram/ml and 5 to 15% at 0.3 microgram/ml. At 0.15 microgram/ml, Adriamycin and menogarol increase the percentage of cells with chromosome damage from a background level of 8.8 to 30 and 22.5%, respectively. The same drug concentration causes a small but significant increase in sister chromatid exchange rate. Both drugs are equally active (increase mutation frequency about 3- to 6-fold above background) in producing 6-thioguanine-resistant mutants. The induction of micronuclei in polychromatic erythrocytes of rats is the most sensitive assay system. Both drugs cause 10- to 15-fold increase in micronuclei at nontoxic doses.

Multidrug resistance in a human small cell lung cancer cell line selected in adriamycin.

A multidrug resistant variant (H69AR) of the human small cell lung cancer cell line NCI-H69 was obtained by culturing these cells in gradually increasing doses of Adriamycin up to 0.8 microM after a total of 14 months. H69AR expresses the multidrug resistant phenotype because it is cross-resistant to anthracycline analogues including daunomycin, epirubicin, menogaril, and mitoxantrone as well as to acivicin, etoposide, gramicidin D, colchicine, and the Vinca alkaloids, vincristine and vinblastine. H69AR is also similar to other multidrug resistant cell lines in that it displays little or no cross-resistance to bleomycin, 5-fluorouracil, and carboplatin. It has a slight collateral sensitivity to 1-dehydrotestosterone and lidocaine. H69AR has increased cell-cell adhesiveness compared to H69, but a similar growth rate in vitro and tumorigenicity in nude mice. When cultured in the absence of Adriamycin, there is a 40% decrease in resistance by 35 days of culture, compared to cells in continuous culture in drug, but no further decrease in resistance up to 181 days. Monoclonal antibodies to P-glycoprotein have no detectable reactivity with H69AR cells as determined by enzyme-linked immunosorbent assay and immunoblotting techniques. Thus, unlike most multidrug resistant cell lines, H69AR does not appear to express enhanced levels of P-glycoprotein. H69AR will provide a useful model for the study of multidrug resistance in human small cell lung cancer.

Phase I clinical investigation of 7-con-O-methylnogaril, a new anthracycline antibiotic.

7-con-O-Methylnogaril (menogaril, NSC-269148) is a new anthracycline antibiotic that has been evaluated in a Phase I clinical trial. The drug was administered in a single i.v. infusion over a period of 60 min given every 3 weeks. Twenty-four patients received 64 courses of the drug in a dose range of 16 to 256 mg/m2. Granulocytopenia was dose limiting and prolonged, requiring treatment delay in 5 of 9 patients treated at doses greater than or equal to 192 mg/m2. Concentration dependent phlebitis occurred in 12 patients, and was of minimal severity when the menogaril concentration was less than 1 mg/ml. Hair loss was experienced by 8 patients but was generally mild with only one patient developing total alopecia. Possible acute cardiac toxicity was noted in one patient who had a transient episode of atrial fibrillation following his fifth course of menogaril. Phase II studies of 7-con-O-methylnogaril are planned at a starting dose of 160 mg/m2 for patients with prior chemotherapy or radiotherapy, and 200 mg/m2 for those without prior therapy given at 28-day intervals.

Effects of 7-R-O-methylnogarol (menogaril) on L1210 cell progression in vitro and in vivo.

Menogaril (7-R-O-methylnogarol) is an anthracycline which has significant antitumor activity in vivo and is in Phase II clinical trial. We report here the drug effect on growth and cell cycle progression of L1210 mouse leukemia cells in vitro and in vivo. At doses which inhibited the growth of L1210 cells in vitro, menogaril slowed the progression of cells through S phase and blocked cells in G2 + M. 7-R-O-Methyl-N-demethylnogarol, the major metabolite of menogaril had the same effects on cell progression in vitro. Menogaril effect on cell progression in vivo was studied with peritoneal L1210 ascites growing in CD2F1 mice. Early in infection, i.e., 3 days after inoculation of 10(5) L1210 cells, DNA histograms of cells from control and drug-treated mice showed only a G1 peak. This presumably represented host diploid G0-G1 cells which predominated in the peritoneal cavity and masked the histogram of L1210 cells. Later in infection, when about 10(8) or more cells were present in the ascites, L1210 cells predominated and DNA histograms were representative of L1210 cells. When menogaril was injected at this time, the cell cycle effects were similar to those seen in vitro. Therefore, the L1210 in vivo model can be used to study cell progression effects only late in infection (when L1210 cells predominate), and due consideration should be given to contamination of the L1210 cells with host G0-G1 cells.

A phase I study of menogaril in patients with advanced cancer.

Menogaril (7-con-O-methylnogarol) is a semisynthetic anthracycline analogue of nogalamycin that has shown good activity against a variety of experimental tumor systems as well as decreased cardiac toxicity when compared with doxorubicin in preclinical studies. Forty-one patients with refractory solid tumors received menogaril during a phase I trial at The Johns Hopkins Oncology Center (Baltimore). Menogaril was administered as an intravenous (IV) infusion on days 1 and 8 of a 28-day cycle in doses of 8 to 140 mg/m2. Eastern Cooperative Oncology Group (ECOG) grade 3 and 4 leukopenia was the principle dose-limiting toxicity and was occasionally accompanied by thrombocytopenia. Both WBC and platelet nadirs occurred between days 15 and 22. Anemia requiring transfusion was occasionally seen. Nonhematologic toxicities observed included frequent anorexia and malaise that was not dose related and postinfusion phlebitis that was dose related and occasionally dose limiting. Gastrointestinal toxicity and alopecia were infrequent and mild in severity. Three patients with cumulative doses of menogaril greater than 1,400 mg/m2 had no significant changes in ejection fractions as determined by serial gated blood pool scans. Two patients had greater than 10% decrements in ejection fractions without clinical changes at total doses of 128 and 288 mg/m2. One patient with prior anthracycline therapy and chest irradiation decreased her left ventricular ejection fraction from 52% to 30% and developed respiratory failure after two cycles of therapy in the setting of disease progression. No responses to menogaril therapy were observed. The recommended phase II dose for menogaril on this day 1 and 8 schedule is 140 mg/m2. A starting dose of 90 mg/m2 should be considered for heavily pretreated patients. In comparing results of this phase I schedule with those of other schedules, evidence for schedule-dependent toxicity differences should be sought.

Phase I study of intravenous menogaril administered intermittently.

Thirty-three adult patients with solid tumors were treated with menogaril, a new anthracycline antibiotic. The drug was given as a two-hour infusion every 4 to 5 weeks at doses ranging from 17 to 250 mg/m2. The maximum tolerated dose was 250 mg/m2. Reversible and dose-related leukopenia was the dose-limiting toxicity. Thrombocytopenia was less frequent. Hematologic toxicity was maximal 2 weeks after treatment, and recovery usually occurred within 4 weeks. There was no dissociation between WBC and neutrophil counts, and myelosuppression did not appear to be cumulative up to 200 mg/m2. Myelosuppression was more severe for patients with heavy pretreatment and/or bone marrow involvement. Local toxicity consisting of phlebitis and/or erythema was the most common nonhematologic toxicity, especially at 250 mg/m2 (eight out of nine patients). Usually, erythema appeared within 24 hours after treatment at or near the infusion site and resolved within a few days. Occasionally, a more persistent (several weeks) orange discoloration suggesting cutaneous deposits of menogaril was observed. Nausea and vomiting were uncommon and never severe. Alopecia and mucositis were rare. Minor arrhythmias were seen in several patients during treatment, but their relationship with menogaril therapy was unclear, and in no patient did heart failure develop. Plasma concentrations were best described by a tricompartmental model with a mean terminal half-life of 29.5 hours and a mean total-body clearance of 20.2 L/h/m2. Doses of 160 and 200 mg/m2 are recommended for phase II trials in poor- and good-risk patients, respectively.

The biochemical pharmacology of nogalamycin and its derivatives.

This review assimilates up-to-date information on the biochemical pharmacology of nogalamycin and selected derivatives that have shown good biological activities and/or received a relatively detailed investigation. The structure and chemical preparation of these derivatives from nogalamycin is described and the nomenclature which has been rather perplexing in the literature is clarified. The interaction of this class of compounds, particularly nogalamycin, with DNA is extensively reviewed. The biochemical mechanism of action of nogalamycin and its structurally closely-related derivatives is described. Among nogalamycin derivatives, menogaril showed distinct biochemical effects as well as superior cytotoxicity and antitumor activity and also proved to be effective against breast cancer clinically.