Mutagenic activity of idarubicin and epirubicin in the bacterium Salmonella typhimurium.
Anthracycline antibiotics, primarily daunomycin and adriamycin, have been utilized in clinical practice since the 1960's and represent one of the most commonly used classes of anticancer drugs against leukemias and solid tissue tumors (reviewed by Sinha & Politi 1990; Hande 1998; Gewirtz 1999; Ogura 2001; Felix 2001). However, these highly active chemotherapeutic agents are also associated with acute cardiotoxic effects and a dose-related cardiomyopathy (reviewed by Hortobagyi 1997; Keefe 2001). Extensive efforts since 1972 have resulted in the replacement of these parent compounds with less toxic "second-generation" structural analogues (reviewed by Arcamone 1984; Carella et al. 1990; Fields & Koeller 1991; Hollingshead & Faulds 1991; Borchmann et al. 1997; Platel et al. 1999). Among these new compounds, 4-methoxy-daunorubicin (idarubicin), a structural analogue of daunomycin, was shown to be effective against acute nonlymphocytic leukemias with reduced cardiotoxic effects in clinical trials (Cersosimo 1992; Bogush & Robert 1996; Andersson et al. 1999; Lee et al. 2001). Similarly, 4'-epidoxorubicin (epirubicin), a 4'-epimer of adriamycin, is now widely used against early and metastatic breast cancers (Ganzina 1983; Weiss 1992; reviewed by Hortabagyi 2000; Razis & Fountzilas 2001; Trudeau & Pagani 2001).
It is known that anthracyclines (particularly the sugar moiety of the compound) can interfere with a number of biochemical and biological functions in the cell. Several studies strongly suggest that membrane binding and poisoning of topoisomerase II activity are possible modes of action for these anticancer antibiotics (Binaschi et al. 1998; Arcamone et al. 1999; Guano et al. 1999; Zunino at al. 2001). However, numerous studies also suggest that the biological activity of these drugs correlate with DNA binding with a preference to the GC bases (Fenick et al. 1997; Taatjes et al. 1997; Davies et al. 2000; Eaton et al. 2000; Qu et al. 2001). Several studies have demonstrated that anthracyclines are mutagenic in prokaryotic and eukaryotic cells (Marzin et al. 1983; Babudri et al. 1984; Olinski et al. 1997; El-Mahdy & Othman 2000; Mackay et al. 2000; Mackay & Phelps 2001). However, the mutagenicity of anthracyclines has been underestimated in the past, partly since these drugs are only "slightly" mutagenic in mic robial assays (Kaldor et al. 1986; Tominaga 1986; Bokemeyer & Schmoll 1995). More recently, however, it has been suggested that the mutagenic properties of anthracyclines during tumor treatment may result in secondary cancers following chemotherapy (Olinski et al. 1997; 1998; Baguley & Ferguson 1998; Vakeva et al. 2000). Thus, it is very important to fully characterize both the mutational spectrum and the mutagenic specificity of anthracyclines as a first step to better understand the antitumor and possible precarcinogenic effects of these compounds.
Efforts in this laboratory have focused primarily in defining the mutagenic specificity of anthracyclines using prokaryotic genotoxicity assays. The use of bacterial mutation assays is now firmly established both for fundamental studies in mutagenesis and carcinogenesis, and for screening chemicals and environmental samples for genotoxic properties. The most used and validated bacterial reverse-mutation assay is the Salmonella Mutagenicity Assay (reviewed by Mortelmans & Zeiger 2000). The original Ames tester strains (i.e., TA98, TA100, etc.) identified mutagens which reverted point mutations in the his operon of Salmonella typhimurium. Although the Salmonella Mutagenicity Assay has been widely used to screen chemicals for potential genotoxicity, it was not originally designed to yield information about the precise nature of the [his.sup.+] revertants that were obtained. For example, TA100 detects primarily GC to AT events, but this strain can also detect GC to TA and extragenic tRNA suppressor mutations (Koc h et al. 1994). TA98 is a tester strain that detects compounds that induce frameshift mutations (Maron & Ames 1983). A new set of Salmonella strains was subsequently generated to identify specific base-substitution events (Gee et ad. 1994; 1998). Since each strain can only revert by a single specific mutational event, it is not necessary to further classify or sequence the resulting revertants in order to know the mutation that has occurred.
Previous studies in this laboratory have shown that daunomycin can induce both frameshift and base-substitution transition mutations in Salmonella typhimurium (Mackay et al. 2000), while adriamycin induces frameshift and GC to AT transition events (Mackay & Phelps 2001). Interestingly, although adriamycin is structurally very similar to daunomycin, it does not induce AT to GC mutations in this assay (Mackay & Phelps 2001). The present study was initiated to examine if the "second-generation" structural analogues of daunomycin and adriamycin, namely idarubicin and epirubicin, could induce frameshift and transition mutations. This report demonstrates that both compounds can induce frameshift, GC to AT, and AT to GC transition events in Salmonella typhimurium.
MATERIALS AND METHODS
Bacterial strains.--The strains and their genotypes used in this study are listed in Table 1. TA98 detects frameshift mutations (Maron & Ames 1983). TA700l and TA7004 are base-substitution specific strains, which carry a target missense mutation in the hisG gene. The latter two strains revert to a prototrophic [his.sup.+] phenotype via a specific basesubstitution event (TA7001, AT to GC, and TA7004, GC to AT) (Gee et al. 1994; 1998).
Chemicals.--Adriamycin (doxorubicin hydrochloride), dimethyl sulfoxide (DMSO), ICR 191 acridine mutagen (6-chloro-9-[3-(2-chloroethylamino)propylamino]-2-methoxy [N.sup.4] - aminocytidine (N4AC), 4-nitroquinoline-N-oxide (4NQO) and streptonigrin (STN) were obtained from Sigma Chemical Co. (St. Louis). Idarubicin (Idamycin[R]) and epirubicin (Ellence[TM]) were obtained from the Erie Cancer Research Center.
Mutation assays. -- The his reversion assays (triplicate assays were conducted for each strain) followed a modified version of the traditional Ames "plate-incorporation" test (Maron & Ames 1983) which utilized a pre-incubation step in order to increase the sensitivity of the strains to each anthracycline compound and has been previously described (Mackay et al. 2000; Mackay & Phelps 2001). Very briefly, 110 [micro]L (approximately 2.0 x [10.sup.8] cells) of a stationary phase S. typhimurium culture (TA98, TA700l, TA7004) was exposed to either daunomycin, idarubicin, adriamycin, or epirubicin (120 [micro]g/mL) for 30 minutes in a shaking incubator (250 rpm) at 37[degrees]C 100 [micro]L of this culture was plated onto minimal agar plates that contained 2% glucose, 0.05 mM L-histidine, and 0.005 mM biotin. These selective plates were incubated at 37[degrees]C, and the numbers of [his.sup.+] revertants were scored after 48 hr. For each strain, a "zero" control (culture that was not exposed to the experimental che mical) was included in order to estimate the number of spontaneous [his.sup.+] revertants in each experiment. The total number of viable cells in each experiment was determined by plating serial dilutions onto nonselective plates (Luria-Bertani, DIFCO). Mutation frequency is expressed as the average number of [his.sup.+] revertants on selective plates divided by the total number of viable cells (determined by the number of colonies on the non-selective plates).
Positive control chemicals.--The Salmonella strains TA98, TA700l, and TA7004 were tested using positive control chemicals that are known to be mutagenic in this assay (Maron & Ames 1983; Gee et al. 1998; Christopher Sommers pers. comm.). ICR 191 was prepared in DMSO (4.0 [micro]g/plate) and used as a positive control for TA98. STN, dissolved in DMSO (50 [micro]g/plate), and N4AC, prepared in sterile deionized water (10 [micro]g/plate) were used as positive controls for TA7001. 4NQO, dissolved in DMSO (0.4 [micro]g/plate), and N4AC (10 [mico]g/plate) were used as positive controls for TA7004.
RESULTS AND DISCUSSION
Previous studies in this laboratory have shown that daunomucin and adriamycin can induce frameshift (i.e., TA98) and GC to AT base-substitution mutations (i.e., TA7004) in the bacterium Salmonella typhimurium (Mackay et al. 2000; Mackay & Phelps 2001). Daunomycin also can induce AT to GC events (i.e., TA7001) in this assay (Mackay et al. 2000). However, adriamycin, a compound that is structurally very similar to daunomycin, did not induce AT to GC mutations in Salmonella (Mackay & Phelps 2001). This current study demonstrates that idarubicin and epirubicin, "second-generation" structural analogues of daunomycin and adriamycin, respectively, can induce frameshift and specific base-substitution transition events.
The Ames tester strains are listed in Table 1. Each Salmonella strain (i.e., TA98, TA7001, TA7004) was first verified using selected positive control chemicals, which have been shown to be mutagenic by Gee et al. (1994; 1998; Sommers, pers. comm.).
Strains TA98, TA700l and TA7004 were exposed to daunomycin, idarubicin, adriamycin, or epirubicin (120 [micro]g/ml). The number of [his.sup.+] revertants were monitored on selective minimal glucose plates and total number of cells on nonselective plates. Following the calculation of the total number of viable cells, it was possible to calculate a mutation frequency for each strain tested (in triplicate). Mutation frequency is expressed as the average number of [his.sup.+] revertants on selective plates divided by the total number of viable cells. The results of this study are summarized in Tables 2 and 3. TA98 was highly mutable (mutation induction folds ranged from 15.4 to 44.5; [chi square]: p < 0.005) when exposed to daunomycin, idarubicin, adriamycin, or epirubicin in this assay. These results demonstrate that the "second-generation" structural analogues, idarubicin and epirubicin, also induced frameshift mutations in this assay. The two base-substitution Ames strains (TA7001, AT to GC; TA7004, GC to AT) were mutable in the presence of daunomycin (mutation induction folds ranged from 7.3 to 7.6; [chi square]: p < 0.005), while TA7004 was mutable in the presence of adriamycin (mutation induction fold 7.8; [chi square]: p < 0.005). As expected from previous studies, adriamycin did not induce AT to GC (TA7001) mutations (mutation induction fold 1.1; [chi square]: p > 0.10) in this assay. Mutation frequencies were also determined for TA700l and TA7004 in the presence of the "second-generation" anthracycline structural analogues, idarubicin and epirubicin. Both strains were mutable in the presence of either compound (mutation induction folds ranged from 2.8 to 14.6; [chi square]: p<0.01). Thus, while adriamycin does not induce AT to GC mutations in Salmonella, the 4'-epimer of this compound, epirubicin, is mutagenic for this transition event.
Several biochemical analyses suggest that the interaction(s) between anthracyclines, primarily daunomycin and adriamycin, and DNA are complex in nature (Davies et al. 2000; Eaton et al 2000; Qu et al. 2001). Anthracyclines can form DNA crosslinks in vivo (Skladanowski & Konopa 1994) and with GC base pairs, specifically a [(GC).sub.4] oligonucleotide, in vitro with formaldehyde (Taatjes et al. 1997; Fenick et al. 1997). The primary mode of action (antitumor effect) of anthracyclines appears to be the intercalation of the aglycone portion of the compound between adjacent DNA base pairs, and this activity results in topoisomerase-induced DNA strand breaks (Liu 1989; Baguley & Ferguson 1998; Zunino et al. 2001). Alkylation of DNA and the production of reactive oxygen species have also been reported to cause DNA modifications during anthracycline chemotherapeutic treatments (Bokemeyer & Schmoll 1995; Olinski et al. 1997). This DNA damage has been found to possess premutagenic properties and, if not repaired, may c ontribute to carcinogenesis (Bokemeyer & Schmoll 1995; Olinski et al. 1998).
The amino sugar is recognized to be a critical determinant of the antitumor activity of daunomycin and adriamycin. In an attempt to improve the pharmacological properties of these anticancer drugs, novel anthracyclines have been designed with altered amino sugars. Epirubicin differs from adriamycin by the epimerization of the OH group in position 4' of the aminosugar moiety and has been shown to be less toxic during chemotherapeutic treatments against metastatic breast cancers (Ganzina 1983; reviewed by Hortabagyi 2000). Idarubicin, a 4-demthoxy-anthracycline analogue of daunomycin, exhibits several features, which render this drug unique among anthracyclines against acute nonlymphocyctic leukemia. Its higher lipophilicity leads to faster accumulation within the nucleus, superior DNA-binding capacity, and consequently, a greater antitumor effect when compared to daunomycin (Borchmann et al. 1997). Furthermore, idarubicin can be administered orally at effective plasma concentrations and exhibits reduced cardio toxicity when administered at therapeutic doses (Cerosimo 1992; Weiss 1992).
These mutational analyses also suggest that the interaction(s) between these anthracyclines and the DNA helix might indeed be very complex. Daunomycin and idarubicin exhibit similar mutagenic effects in Salmonella (Table 2). However, the slight differences in structure between adriamycin and epirubicin give rise to different mutational spectra in this assay. Both compounds can induce GC to AT transition mutations (Mackay & Phelps 2001; this report). However, unlike epirubicin, which can also induce AT to GC mutations (Table 3), adriamycin is not mutagenic with TA7001 in the Salmonella Mutagenicity Assay (Mackay et al. 2000). These results suggest that there may exist small chemical differences between the binding of each antibiotic with DNA and also suggest that unique interactions of epirubicin and adriamycin with DNA might provide an explanation for the significantly different clinical activities of the two anticancer drugs.
The incidence of many secondary cancers has been linked to high doses of chemotherapy (Kaldor et al. 1987; Swendlow et al. 1992; Olinski et al. 1997, 1998; Allen et al. 1998; Baguley & Ferguson 1998; Vakeva et al. 2000). In order to improve the clinical efficacy of antineoplastic anthracycline compounds (i.e., daunomycin, adriamycin, epirubicin and idarubicin) during chemotherapy, it will be necessary to identify modulators of their activities that could potentially be exploited to sensitize target tissues to therapy or to protect nontarget tissues during therapy. Such modulators include metabolic activation pathways and DNA repair pathways.
Anthracyclines can induce DNA crosslinks (Cullinane & van Rosmalen 1994; Cullinane et al. 2000). All cells have base excision repair mechanisms, which can recognize and remove cross-linking base adducts. For example, 3-methyladenine DNA glycosylase (Aag) recognizes and removes a variety of these DNA adducts (e.g., groups that can attach at the N7 and N3 positions of the purine ring) (reviewed by Seeberg et al. 2000). Escherichia coli mutants (alkA tag), which lack Aag activity, are extremely sensitive to killing in the presence of monofunctional (for example, methylmethanesulfonate) and complex (for example, BCNU) alkylating agents (Evensen & Seeberg 1982; Clarke et al. 1984; Engelward et al. 1996). Furthermore, addition of a mouse gene, which encodes Aag, to alkA tag cells, restores partial resistance to cell killing in the presence of several alkylating and DNA crosslinking agents (Engelward et al. 1993). Future endeavors within this laboratory will determine if a base-excision repair pathway that includes Aag can recognize and repair anthracycline-induced DNA cross-links. Hopefully, these results may lead to a lessening of the detrimental effects of anthracycline compounds and/or increased antitumor efficacies of these drugs in future cancer chemotherapeutic treatments. These experiments are currently in progress.
Table 1 Ames Salmonella strains. Strain Genotype Mutation Detected TA7001 hisG1775 [DELTA]ara9 [DELTA]chl1004 A:T to G:C (bio chlD uvrB chlA) galE503 rfa1041/pKM101 TA7004 hisG9133 [DELTA]ara9 [DELTA]chl1004 G:C to A:T (bio chlD uvrB chlA) galE503 rfa1044/pKM101 TA98 hisD3052 [DELTA]ara9 [DELTA]chl1008 frameshift (bio chlD uvrB gal) rfa1004/pKM101 (-1 C) Table 2 Daunomycin/Idarubicin mutation frequencies of Ames Salmonella stains. Strain Spontaneous Mutation Frequency (S) TA7001 0.9 ([+ or -] 0.1) X [10.sup.-8] Ta7004 0.8 ([+ or -] 0.1) X [10.sup.-7] Ta98 1.1 ([+ or -] 0.3) X [10.sup.-7] Strain Induced Mutation Induction Fold Frequency (1) (daunomycia) (120 [micro]g/ml daunomycin) (I/S) TA7001 6.6 ([+ or -] 0.1) X [10.sup.-8] 7.3 Ta7004 6.1 ([+ or -] 0.6) X [10.sup.-7] 7.6 Ta98 4.9 ([+ or -] 0.5) X [10.sup.-6] 44.6 Strain Induced Mutation Induced Fold Frequency (1) (idarubicin) (120 [micro]g/ idarubicin) (I/S) TA7001 2.6 ([+ or -] 0.1) X [10.sup.-8] 2.8 Ta7004 7.0 ([+ or -] 0.1) X [10.sup.-7] 8.7 Ta98 1.8 ([+ or -] 0.3) X [10.sup.-6] 16.1 Table 3 Adriamycin/Epirubicin mutation frequencies of Ames Salmonella stains. Strain Spontaneous Mutation Frequency (S) TA7001 0.9 ([+ or -]0.1) X [10.sup.-8] TA7004 0.8 ([+ or -]0.1) X [10.sup.-7] TA98 1.1 ([+ or -]0.3) X [10.sup.-6] Strain Induced Mutation Induction Fold Frequency (I) (adriamycin) (120 [micro]g/ml adriamycin) (I/S) TA7001 1.0 ([+ or -] 0.1) X [10.sup.-8] 1.1 TA7004 6.2 ([+ or -] 0.7) X [10.sup.-7] 7.8 TA98 1.7 ([+ or -] 0.4) X [10.sup.-4] 15.4 Strain Induced Mutation Induction Fold Frequency (I) (epirubicin) (120 [micro]g/ml epirubicin) (I/S) TA7001 2.6 ([+ or -] 0.1) X [10.sup.-8] 2.9 TA7004 1.2 ([+ or -] 0.1) X [10.sup.-6] 14.6 TA98 2.2 ([+ or -] 0.3) X [10.sup.-6] 19.7
The authors wish to thank Dr. Christopher Sommers for sharing his unpublished results and Dr. Susan Rosendahl for idarubicin and epirubicin. This research was partly supported by a Beta Beta Beta Foundation Research Scholarship to the senior author.
Allen, J. M., B. P. Engelward, A. J. Dreslin, M. D. Wyatt, M. Tomasz & L. U. Samson. 1998. Mammalian 3-methyladenine DNA glycosylase protects against the toxicity and clastogenicity of certain chemotherapeutic DNA cross-linking agents. Cancer Res., 58(17):3965-3973.
Andersson, B. S., S. Eksborg, R. F Vidal, M. Sundberg & M. Carlberg. 1999. Anthraquinone-induced cell injury: acute toxicity of carminomycin, epirubicin, idarubicin and mitoxantrone in isolated cardiomyocytes. Toxicology, 135(1):ll-20.
Arcanone, F. 1984. Adriamycin and its analogs. Tumori, 70(2):113-119.
Arcamone, F., F. Animati, M. Bigioni, G. Capranico, C. Caserinin, A. Cipollone, M. De Cesare, A. Ettore, F. Guano, S. Manzini, E. Monteagudo, G. Pratesi, C. Salvatore, R. Supino & F. Zunino. 1999. Configurational requirements of the sugar moiety for the pharnialogical activity of anthracycline disaccharides. Biochem. Pharmacol., 57(10):1133-1139.
Babudri, N., B. Pani, M. Tamaro, C. Monti-Bragadin & F. Zunino. 1984. Mutagenic and cytotoxic activity of doxorubicin and daunorubicin derivatives on prokaryotic and eukaryotic cells. Br. J. Cancer, 50(1):91-96.
Baguley, B. C. & L. R. Ferguson. 1998. Mutagenic properties of topoisomerase-targeted drugs. Biochim. Biophys. Acts., 1400(1-3):213-222.
Binaschi, M., R. Farinosi, C. A. Austin, L. M. Fisher, F. Zunino & G. Capranico. 1998. Human DNA topisomerase Ilaipha-dependent DNA cleavage and yeast cell killing by anthracycline analogues. Cancer Res., 58(9):1886-1892.
Bogush, T. & J. Robert. 1996. Comparative evaluation of the intracellular accumulation and DNA binding of idarubicin and daunorubicin in sensitive and multidrug-resistant human leukaemia K562 cells. Anticancer Res., 16(l):365-368.
Bokemeyer, C. & H. J. Scbmoll. 1995. Treatment of testicular cancer and the development of secondary malignancies. J. Clin. Oncol., 13(l):283-292.
Borchmann, P. K. Hyubel, R. Schnell & A. Engert. 1997. Idarubicin: a brief overview on pharmacology and clinical use. Int. J. Clin. Pharmacol. Ther., 35(2):80-83.
Carella, A. M., E. Berman, M. P. Maraone & F. Ganzina. 1990. Idarubicin in the treatment of acute leukemias. An overview of preclinical and clinical studies. Haematologica, 75(2):159-169.
Cersosimo, R. J. 1992. Idarubicin: an anthracycline antineoplastic agent. Clin. Pharm., 1l(2):152-167.
Clarke, N., M. Kvaal & E. Seeberg. 1984. Cloning of E. coli genes encoding 3-methyladenine DNA glycosylases I and II. Mol. Gen. Genet., 197(1):368-378.
Cullinane, C., & A. van Rosmalen. 1994. Does adriamycin induce interstrand cross-links in DNA? Biochemistry, 33(15):4632-4638.
Cullinane, C., S. M. Cutts, C. Panousis & D. R. Phillips. 2000. Interstrand cross-linking by adrianiycin in nuclear and mitochondrial DNA of MCF-7 cells. Nucleic Acids Res., 28(4):1019-1025.
Davies, D. B., R. J. Eaton, S. F. Baranovsky & A. N. Veselkov. 2000. NMR investigation of the complexation of daunomycin with deoxytetranucleotides of different base sequence in aqueous solution. J. Biomol. Struct. Dyn., 17(5):887-901.
Eaton, R. J., D. A. Baranovskii, D. A. Veselkov, S. G. Osetrov, P. A. Bolotin, L. N. Dymant, V. I. Pakliomov, D. V. Davis & A. N. Veselkov. 2000. Study of the complex formation of daunomycin with deoxytetranucleotides with bases of differing sequence in an aqueous solution by IH-NMR spectroscopy. Biofizika, 45(4):586-599.
EI-Mahdy, S. & 0. Othman. 2000. Cytogenetic effect of the anti-cancer drug epirubicin on Chinese hamster cell in vitro. Mutat. Res., 468(2):109-115.
Engelward, B. P., M. S. Boosalis, B. J. Chen, Z. Deng, M. J. Siciliano & L. D. Samson. 1993. Cloning and characterization of a mouse 3-methyladenine/7-methylguanine/3-methylguanine DNA glycosylase cDNA whose gene maps to chromosome II. Carcinogenesis, 14(2):175-181.
Engelward, B. P., A. Dreslin, J. Christensen, D. Huszar, C. Kurahara & L. Samson. 1996. Repair-deficient 3-methyladenine DNA glycosylase homozygous mutant mouse cells have increased sensitivity to alkylation-induced chromosome damage and cell killing. EMBO J., 15:945-952.
Evensen, G. & E. Seeberg. 1982. Adaptation to alkylation resistance involves the induction of a DNA glycosylase. Nature, 296(l):775-779.
Felix, C. A. 2001. Leukemias related to treatment with DNA topisomerase II inhibitors. Med. Pediatr. Oncol., 36(5):525-535.
Fenick, D. J., D. J. Taatjes & T. H. Koch. 1997. Doxoform and daunoform: Anthracycline-formaldehyde conjugates toxic to resistant tumor cells. J. Med. Chem., 40(16):2452-2461.
Fields, S. M. & J. M. Koeller. 1991. Idarubicin: a second-generation anthracycline. DICP, 25(5):505-517.
Ganzina, F. 1983. 4'-epi-doxorubicin, a new analogue of doxorubicin: a preliminary overview of preclinical and clinical data. Cancer Treat. Rev., 10(1):1-22.
Gee, P., D. Maron & B. N. Ames. 1994. Detection and classification of mutagens: A set of base-specific Salmonella tester strains. Proc. Natl. Acad. Sci. USA, 91(24):11606-11610.
Gee, P., C. H. Sommers, A. S. Melick, X. M. Gidrol, M. D. Todd, R. B. Burris, M. E. Nelson & E. Zeiger. 1998. Comparison of responses of base-specific Salmonella tester strains with the traditional strains for identifying mutagens: the results of a validation study. Mutation Res., 412(2):115-130.
Gewirtz, D. A. 1999. A critical evaluation of the mechanisms of action proposed for the antitumor effects of the anthracycline antibiotics adniamycin and daunorabicin. Biochem. Pharmacol., 57(7):727-741.
Guano, F., P. Pounquier, S. Tinelli, M. Binaschi, M. Bigioni, F. Animati, S. Manzini, F. Zunino, G. Kohlhagen, Y. Pommier & G. Capranico. 1999. Topoisomerase poisoning activity of novel disaccharide anthracyclines. Mol. Pharmacol., 56(1):77-84.
Hande, K. R. 1998. Clinical applications of anticancer drugs targeted to topoisomerase II. Biochim. Biophys. Acta., 1400(1-3):173-184.
Hollingshead, L. M. & D. Faulds. 1991. Idarubicin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in the chemotherapy of cancer. Drugs, 42(4):690-719.
Hortobagyi, G. N. 1997. Anthracyclines in the treatment of cancer: An overview. Drugs, 54(S4):1-7.
Hortobagyi, G. N. 2000. Developments in chemotherapy of breast cancer. Cancer, 88(12 SUPPL):3073-3079.
Kaldor, J. M., N. E. Day & S. Shiboski. 1986. Epidemiological studies of anticancer drug carcinogenicity. IARC Sci. Publ., 78(1): 189-201.
Kaldor, J. M., N. E. Day, P. Band, N. W. Choi, E. A. Clarke, M. P. Coleman, M. Hakama, M. Koch, F. Langmark, F. E. Neal, F. Pettersson, V. Pompe-Kim, P. Prior & H. H. Storm. 1987. Second malignancies following testicular cancer, ovarian cancer, and Hodgkin's disease: an international collaborative study among cancer registries. Int. J. Cancer, 39(1):571-585.
Keefe, D. L. 2001. Anthracycline-induced cardiomyopathy. Semin. Oncol., 28(4 Suppl 12):2-7.
Koch, W. H., E. N. Henrikson, E. Kupchella & T. A. Cebula. 1994. Salmonella typhimurium strain TA100 differentiates several classes of carcinogens and mutagens by base substitution specificity. Carcinogenesis, 15(1):79-88.
Lee, S. T., J. H. Jang, H. C. Suh, J. S. Hahn, Y. W. Ko & Y. H. Min 2001. Idarubicin, cytarabine, and topotecan in patients with refractory or relapsed acute myelogenous leukemia and high-risk myelodysplastic syndrome. Am. J. Hematol., 68(4):237-245.
Liu, L. F. 1989. DNA topoisomerase poisons as antitumor drugs. Annu. Rev. Biochem., 58:351-375.
Mackay, W. J., L. A. Phelps, A. A. Cauchi & L. T. Weaver. 2000. The mutagenic effects of anthracyclines in the bacterium Salmonella typhimurium: Induction of transition mutations with daunomycin. Texas J. Sci., 52(3):223-229.
Mackay, W. J. & L. A. Phelps. 2001. The induction of GC to AT transition mutations with adriamycin in the bacterium Salmonella typhimurium. Texas J. Sci., 53(3):239-246.
Maron, D. M & B. N. Ames. 1983. Revised methods for the Salmonella mutagenicity test. Mutation Res., 113(3-4):173-215.
Marzin, D., C. Jasmin, R. Maral & G. Mathe. 1983. Mutagenicity of eight anthracycline derivatives in five strains of Salmonella typhimurium. Eur. J. Cancer Clin. Oncol., 19(5):641-647.
Mortelmans, K. & E. Zeiger. 2000. The Ames Salmonella/microsome mutagenicity assay. Mutat. Res., 455(1-2):29-60.
Ogura, M. 2001. Adriamycin (doxorubicin). Gan To Kagaku Ryoho, 28(10):1331-1338.
Olinski, R., P. Jaruga, M. Foksinski, K. Bialkowski & J. Tujakowski. 1997. Epirubicin-induced oxidative DNA damage and evidence for its repair in lymphocytes of cancer patients who are undergoing chemotherapy. Mol. Pharmacol., 52(5)882-885.
Olinski, R., P. Jaruga & T. H. Zastawny. 1998. Oxidative DNA base modifications as factors in carcinogenesis. Acta. Biochim. Pol., 45(2):561-572.
Platel, D., P. Pouna, S. Bonoron-Adyele & J. Robert. 1999. Comparative cardiotoxicity of idarubicin and doxorubicin using the isolated perfused rat heart model. Anticancer Drugs, 10(7):671-676.
Qu, X., C. Wan, H. C. Becker, D. Zhong & A. H. Zewail. 2001. The anticancer drug-DNA complex: Femtosecond primary dynamics for anthracycline antibiotics function. Proc. Natl. Acad. Sci. USA, 98(25)14212-14217.
Razis, E. D. & G. Fountzilas. 2001. Paclitaxel: epirubicin in metastatic breast cancer--a review. Ann. Oncol., 12(5):593-598.
Seeberg, E., L. Luna, I. Morland, L. Eide, B. Johnsen, E. Larsen, I. Alseth, F. Dantzer, K. Baynton, R. Aamodt, K. I. Kristiansen, T. Rognes, A. Klungland & M. Bjoras. 2000. Base removers and strand scissors: Different strategies employed in base excision and strand incision at modified residues in DNA. Cold Spring Harbor Symp. Quant. Biol., 65(1):135-142.
Sinha, B. K. & P. M. Politi. 1990. Anthracyclines. Cancer Chemother. Biol. Response Modif., l1(1):45-57.
Skladanowski, A. & J. Konopa. 1994. Interstrand DNA crosslinking induced by anthracyclines in tumor cells. Biochem. Pharmacol., 47(12):2269-2278.
Swendlow, A. J., A. J. Douglas & C. V. Hudson. 1992. Risk of second primary cancers after Hodgkin's disease by type of treatment analysis of 2846 patients in the British National Lymphoma Investigation: relationships to host factors, histology, and stage of Hodgkin's disease, and splenectomy. Br. Med. J., 304(1):1137-1143.
Taatjes, D. J., G. Gaudiano, K. Resing & T. H. Koch. 1997. Redox pathway leading to the alkylation of DNA by the anthracycline, antitumor drugs adriamycin and daunomycin. J. Med. Chem. 40(8):1276-1286.
Tominaga, S. 1986. Epidemiologic methods of estimation of a secondary cancer associated with cancer treatment. Gan To Kagaku Ryoho, 13(4 Pt 2):1528-1533.
Trudeau, M. & O. Pagani. 2001. Epirubicin in combination with the taxanes. Semin. Oncol., 28(4 Suppl 12):41-50.
Vakeva, L., E. Pukkala & A. Ranki. 2000. Increased risk of secondary cancers in patients with primary cutaneous T cell lymphoma. J. Invest. Dermatol., 115(1):62-65.
Weiss, R. B. 1992. The anthracyclines: will we ever find a better doxorubicin? Semin. Oncol., 19(6):670-686.
Zunino, F., G. Pratesi & P. Perogo. 2001. Role of the sugar moiety in the pharmalogical activity of anthracyclines: development of a novel series of disaccharide analogs. Biochem. Pharmacol., 61(8):933-938.
WJM at: firstname.lastname@example.org
|Printer friendly Cite/link Email Feedback|
|Author:||Brumfield, John M.; Mackay, William J.|
|Publication:||The Texas Journal of Science|
|Date:||Aug 1, 2002|
|Previous Article:||Noteworthy plants associated with the gulf Coastal Bend of Texas.|
|Next Article:||The effects of incubation temperature on locomotor activity in juvenile Hogna carolinensis (Araneae: Lycosidae).|