Micronucleus and antitumor activities of two newly synthesized pyrimidine derivatives

Micronucleus and antitumor activities of two newly synthesized iodides of pyrazolo[1,5a]pyrimidines were studied on mice. Both compounds were slightly toxic and had no antitumor activity in mice with Ehrlich ascites carcinoma; only one of them had low micronucleus activity. Both compounds substantially increase the micronucleus as well as the antitumor activities of cyclophosphamide.     

Relationship between the chemical structures and biological activities (toxicity, mutagenic and antitumor) in newly synthesized derivatives of pyrazolo pyrimidines

The relationship between chemical structure, micronucleus-inducing and antitumor activities was studied in four newly synthesized pyrazolo pyrymidine compounds (DGB-216, DGB-227, DGB-228 and DGB-331). In bone marrow erythrocytes of mice no one of compounds was active. Only DGB-216 has slight antitumor activity and increases the mean life span of mice with Ehrlich ascite carcinoma by 11%, while others were practically non-active. Changes in the chemical structures of the compounds lead to substantial changes in the acute toxicity only. The search of antitumor compounds among the derivatives of -6-etoxycarbonyl-pyrazolo[1,5a]-pyrymidine and -2-methyl-pyrazolo[1,5a]-pyrymidine is useless, as it has been shown in the present investigation. But the search of compounds with antitumor properties among derivatives of pyrazolo pyrymidines is a perspective idea because recently some very active antitumor compounds based on mentioned strusture were synthesized in Italy and the USA.     

Design,synthesis and evaluation of novel HDAC inhibitors as potential antitumor agents

Phenyl imidazolidin-2-one was introduced as the linker for novel HDAC inhibitors. A focused library of 20 compounds was designed and synthesized, among which eight compounds showed equivalent or higher potencies against HDAC1 as compared to vorinostat. In vitro antitumor activity assays in HCT-116, PC-3 and HL-60 cancer cells revealed six compounds with potent antitumor activities, and compound 1o showed 6- to 9-fold higher potencies compared to vorinostat. In an HCT-116 nude mice xenograft model, compound 1o displayed significant antitumor activity in both continuous and intermittent dosing schedules.     

2,5-Disubstituted-1,3,4-oxadiazoles/thiadiazole as surface recognition moiety: design and synthesis of novel hydroxamic acid based histone deacetylase inhibitors

The enzymatic inhibition of histone deacetylase activity has come out as a novel and effectual means for the treatment of cancer. Two novel series of 2-[5-(4-substitutedphenyl)-[1,3,4]-oxadiazol/thiadiazol-2-ylamino]-pyrimidine-5-carboxylic acid (tetrahydro-pyran-2-yloxy)-amides were designed and synthesized as novel hydroxamic acid based histone deacetylase inhibitors. The antiproliferative activities of the compounds were investigated in vitro using histone deacetylase inhibitory assay and MTT assay. The synthesized compounds were also tested for antitumor activity against Ehrlich ascites carcinoma cells in Swiss albino mice. The efforts were also made to establish structure-activity relationships among synthesized compounds. The results of the present studying indicates 2,5-disubstituted 1,3,4-oxadiazole/thiadiazole as promising surface recognition moiety for development of newer hydroxamic acid based histone deacetylase inhibitor.     

Synthesis,cytotoxicity, and in vivo antitumor activity study of parthenolide semicarbazones and thiosemicarbazones

Parthenolide is an important sesquiterpene lactone with potent anticancer activities. In order to further improve its biological activity, a series of parthenolide semicarbazone or thiosemicarbazone derivatives was synthesized and evaluated for their anticancer activity. Derivatives were tested in vitro against 5 human tumor cell lines, and many of these showed higher cytotoxicity than parthenolide. Five compounds were further studied for their antitumor activity in mice. The in vivo result indicated that compound 4d showed both promising antitumor activity against mice colon tumor and small side effects on immune systems. The cell apoptosis and cell cycle distribution of compound 4d were also studied. Molecular docking studies revealed multiple interactions between 4d and NF-κB. Our findings demonstrate the potential of semicarbazones as a promising type of compounds with anticancer activity.     

Synthesis, acute toxicities, and antitumor effects of novel 9-substituted beta-carboline derivatives

A series of novel 9-substituted beta-carboline derivatives was synthesized from harmine and l-tryptophan, respectively. Cytotoxic activities of these compounds in vitro were investigated. The results showed that most compounds of 9-substituted beta-carboline derivatives had more remarkable cytotoxic activities in vitro than their corresponding parent compounds. Acute toxicities and antitumor effects of the selected beta-carboline derivatives in mice were also examined. The results demonstrated that a short alkyl or benzyl substituent at position-9 increased the antitumor activities significantly and a ethoxycarbonyl or carboxyl substituent at position-3 reduced the acute toxicity and neurotoxicity of these beta-carboline derivatives dramatically. Moreover the compounds both with an alkoxycarbonyl or carboxyl substituent at position-3 and a short alkyl or benzyl substituent at positon-9 exhibited more significant antitumor activities and lower acute toxicities and neurotoxicities than the other compounds. The compound 8c, having an n-butyl and a carboxyl substituent at position-9 and 3, respectively, was found to have the highest antitumor effect and the lowest acute toxicity and neurotoxicity. These data suggested that (1) appropriate substituents at both position-9 and 3 of beta-carboline derivatives might play a crucial role in determining their enhanced antitumor activities and decreased acute toxicities and neurotoxic effects; (2) the beta-carboline derivatives have the potential to be used as antitumor drug leads.     

Synthesis of seleno- and thio-guanine-Pt (II) complexes and their antitumor activity in mice

Selenoguanine- and selenoguanosine-platinum(II) complexes were synthesized, and their atitumor activities against L1210 in mice and against in vitro tissue culture system were studied. These compounds exhibited antitumor activity of medium strength and showed very low toxicity. The effect of the SeG-Pt (II) complex in mice was retained longer than that of the parent compound SeG because the SeG-Pt (II) complex very slowly released SeG into blood.     

Synthesis, screening and quantitative structure-activity relationship (QSAR) studies of some glutamine analogues for possible anticancer activity

We described the syntheses, biological activities and QSAR studies of 36 new 5-n-substituted-2-(substituted benzenesulphonyl) glutamines 6-41 with different substitutions. These compounds were designed as structural analogues of most reactive amino acid, 'glutamine' (GLN), especially in the tumor cells. They present the new basic lateral chains at R(5) position as well as different substitutions at 2', 3', 4', and 5' positions on the benzene ring. The synthesized compounds have been tested for antitumor activity against Ehrlich ascites carcinoma (EAC) in Swiss albino mice using percentage inhibition of tumor weight as inhibitory parameter. In order to elucidate the structural requirements for antitumor activity, quantitative structure-activity relationship (QSAR) studies have been performed using extra thermodynamic model of Hansch. QSAR equations showed that the electronic parameter (sigma) on the aromatic ring system, steric parameter (Es) and to some extent Sterimol length of the substituent (L) on the aliphatic side chain correlate significantly with the antitumor activity. Resonance factor occupies the major electronic contribution on the aromatic ring system to the activity.     

Relationships between structures and mutagenic potencies of 16 heterocyclic nitrogen mustards (ICR compounds) in Salmonella typhimurium

16 heterocyclic nitrogen mustards (ICR compounds), which were synthesized for use as possible antitumor agents by Creech and coworkers, were tested for mutagenicity in Salmonella typhimurium strains TA1535, TA1536, TA1537, TA1538, TA98 and TA100. The compounds were incorporated into the top agar at 5 doses: 0.5, 1, 2.5, 5 and 10 micrograms/plate. All of the compounds were negative in TA1535 except ICR 449, which was positive in all 6 strains. The other 15 compounds were positive in the remaining strains with the following exceptions: ICR 371 and 355 were negative in TA100; ICR 445 was negative in TA98 and TA100; and ICR 360 was negative in TA1537, TA1538, TA98 and TA100. Good qualitative agreement was observed between the mutagenic and antitumor activities of the 16 compounds, and between the mutagenic and carcinogenic activities of the 5 compounds that have been tested for carcinogenicity by Peck and coworkers. However, no significant correlation was found between mutagenic potency in Salmonella and antitumor potency in mice for the 16 compounds. Also, for the 5 compounds that have been tested for carcinogenicity, no significant correlation was found between their mutagenic potency in Salmonella and their carcinogenic potency in mice. In Salmonella, the secondary (2 degrees) amines generally were more mutagenic than their tertiary (3 degrees) amine homologs, although the opposite result has been reported in certain eukaryotes. Relationships between structures and potencies for the different nuclei of the 16 ICR compounds are discussed, as are similarities and differences in strain sensitivities. We conclude that the Salmonella his reversion test is not a good predictor of the antitumor and carcinogenic potencies of these ICR compounds.     

Micronuclei and the cytoplasm of growing Tetrahymena contain a histone acetylase activity which is highly specific for free histone H4

Salt extracts prepared from purified micronuclei and the cytoplasm of growing Tetrahymena contain a histone acetylase (also referred to as histone acetyltransferase) activity which is highly specific for H4 when tested as a free histone. With both extracts, H4 is acetylated first at position 4 (monoacetylated) or positions 4 and 11 (diacetylated), sites diagnostic of deposition-related acetylation of newly synthesized H4 in vivo. As the concentration of cytosolic extract is decreased in the in vitro reactions, acetylation of H3 is also observed. Neither activity acetylates histone in a chromatin form. These activities are distinct from a macronuclear acetylase which acetylates H3 and H4 (macro- or micronuclear) equally well as free histones and which acetylates all four core histones when mononucleosomes are used as substrate. As well, the micronuclear and cytoplasmic activities give similar thermal-inactivation profiles which are different from that of the macronuclear activity. In situ enzyme assays demonstrate a macronuclear-specific activity which acetylates endogenous macronuclear chromatin and an independent micronuclear-cytosolic activity which is able to act upon exogenously added free H4. These results argue strongly that an identical acetylase is responsible for the micronuclear and cytoplasmic activity which is either modified or altogether distinct from that in macronuclei.     

Macrophage activation by Lactobacillus casei in mice

Effects of Lactobacillus casei YIT 9018 (LC 9018), which has antitumor activities against allogeneic and syngeneic murine tumors, on macrophage functions were examined. By intraperitoneal (i.p.) injection of LC 9018, acid phosphatase activity and phagocytic activity of peritoneal macrophages were enhanced significantly compared with those of normal peritoneal macrophages. The phagocytic activities showed peaks 2-3 days after the LC 9018-injection. LC 9018 accelerated the phagocytic function of the reticuloendotherial system in ICR mice tested by the carbon clearance test. The cytostatic activity of peritoneal exudate cells (PEC) induced by i.p. injection of LC 9018 into C57BL/6 mice against EL4 cells was also enhanced. On the other hand, PEC induced by L. fermentum YIT 0159, which has no antitumor activity, did not have cytostatic activity. These observations showed that LC 9018 was able to activate macrophages in mice.     

乳酸杆菌发酵液RNA的抗肿瘤及对巨噬细胞功能的调节作用

目的研究乳酸杆菌DM9811发酵滤液中存在的100200 bp长的RNA片段（Ls-RNA）的免疫调节与抗肿瘤作用。方法采用中性红吞噬试验检测巨噬细胞吞噬功能,用L929细胞检测TNF,用免疫保护试验检测体内抗肿瘤作用。结果Ls-RNA可增强脾巨噬细胞的吞噬活性,对小鼠肝癌Hca-F的生长有抑制作用,延长小鼠的存活时间,但对TG诱导的腹腔巨噬细胞产生TNF无明显调节作用。结论Ls-RNA有一定免疫调节和抗肿瘤作用。     

Modulation of adriamycin toxicity by tissue-specific induction of metallothionein synthesis in mice

The effect of tissue specific induction of metallothionein (MT) by preadministration of metal compounds on the antitumor activity and adverse effects of adriamycin (ADR) was examined using mice bearing colon 38 adenocarcinoma. Significant increase in MT concentration was observed in the heart and bone marrow but not in the tumor tissue of the mice given bismuth (Bi) compound. Copper (Cu) increased MT in the tumor tissue but did not induce MT either in bone marrow or in the heart, whereas zinc (Zn) increased MT level in the heart and bone marrow as well as in the tumor tissue. ADR exerted cardiotoxicity, indicated by increase in lipid peroxidation in the heart, bone marrow toxicity, indicated by decrease in number of peripheral leukocytes, and antitumor activity, assessed by reduction of tumor weight, in tumor-bearing mice untreated with MT inducing metal compounds. Preadministration of Bi significantly reduced the cardiotoxicity and bone marrow toxicity without compromising the antitumor activity of ADR. Cu pretreatment did not affect the extent of cardiotoxicity and bone marrow toxicity but significantly suppressed the antitumor effect. Pretreatment with Zn markedly reduced not only the adverse side effects but also the antitumor activity. The results described above suggest that ADR toxicity can be attenuated in the tissues in which the MT level was elevated and that the tissue specific induction of MT synthesis may provide a promising regimen for cancer chemotherapy.     

Synthesis and biological validation of novel pyrazole derivatives with anticancer activity guided by 3D-QSAR analysis

Using literature data on anticancer activity of pyrazole derivatives, 3D-QSAR models were developed and 3D-QSAR analysis was performed. The 3D-QSAR analysis enabled identification of molecular properties that have the highest impact on antitumor activity against lung cancer cells. The results of 3D-QSAR analysis were taken into account while new compounds were designed. Obtained 3D-QSAR models were used for prediction of activity of new compounds. In this way, design of new compounds was guided by 3D-QSAR analysis which was performed on literature data. Ten new pyrazole derivatives were synthesised and their antitumor activities against A549 and NCIH23 lung cancer cells were validated. In order to obtain full profile of anticancer activity, cells viability (MTS) assays were combined with cell proliferation (BrdU) assays which measure actively dividing cells in treated sample. Experimental measurements showed good agreement between predicted and measured activities for majority of compounds. Also, anticancer activities of new pyrazole derivatives pointed to the chemical groups that can be useful in designing antitumor molecules. Substitution of hydrazine linker with rigid, 1,2,4-oxadiazole moiety resulted in compound 10, which has low (if any) cytotoxic activity and high potential cytostatic activity. Therefore, compound 10 presents a good starting point for design of new, more potent and safer anticancer therapeutics.     

Analysis of the number of normochromic erythrocytes with micronuclei in the peripheral blood of mice as a method of detecting mutagens

Cytogenic damages both in the bone marrow (5.5-fold increase in the number of cells with chromosomal aberrations) and in the peripheral blood of mice (4.5-fold increase in the frequency of micronuclear polychromatic erythrocytes and 3-fold rise in the number of micronuclear normochromic erythrocytes, as compared to the control) have been observed after a two-week administration of 0.01% cyclophosphamide with drinking water. The micronuclear test on mature erythrocytes from peripheral blood of mice can be an effective method for the identification of mutagenic properties of the factor under study during its long-term action.     

Antiangiogenic and antitumor activities of IL-27

IL-27 is a novel IL-6/IL-12 family cytokine playing an important role in the early regulation of Th1 responses. We have recently demonstrated that IL-27 has potent antitumor activity, which is mainly mediated through CD8(+) T cells, against highly immunogenic murine colon carcinoma. In this study, we further evaluated the antitumor and antiangiogenic activities of IL-27, using poorly immunogenic murine melanoma B16F10 tumors, which were engineered to overexpress single-chain IL-27 (B16F10 + IL-27). B16F10 + IL-27 cells exerted antitumor activity against not only s.c. tumor but also experimental pulmonary metastasis. Similar antitumor and antimetastatic activities of IL-27 were also observed in IFN-gamma knockout mice. In NOD-SCID mice, these activities were decreased, but were still fairly well-retained, suggesting that different mechanisms other than the immune response are also involved in the exertion of these activities. Immunohistochemical analyses with Abs against vascular endothelial growth factor and CD31 revealed that B16F10 + IL-27 cells markedly suppressed tumor-induced neovascularization in lung metastases. Moreover, B16F10 + IL-27 cells clearly inhibited angiogenesis by dorsal air sac method, and IL-27 exhibited dose-dependent inhibition of angiogenesis on chick embryo chorioallantoic membrane. IL-27 was revealed to directly act on HUVECs and induce production of the antiangiogenic chemokines, IFN-gamma-inducible protein (IP-10) and monokine induced by IFN-gamma. Finally, augmented mRNA expression of IP-10 and monokine induced by IFN-gamma was detected at the s.c. B16F10 + IL-27 tumor site, and antitumor activity of IL-27 was partially inhibited by the administration of anti-IP-10. These results suggest that IL-27 possesses potent antiangiogenic activity, which plays an important role in its antitumor and antimetastatic activities.     

Synthesis and biological evaluation of 7-alkenyl homocamptothecins as potent topoisomerase I inhibitors

Homocamptothecin (hCPT) is a camptothecin (CPT) derivative with a seven-membered β-hydroxylactone E ring, which shows higher lactone stability and improves topoisomerase I (Topo I) inhibition activity. In an attempt to improve the antitumor activity of homocamptothecins, a series of 7-alkenyl-homocamptothecin derivatives was designed and synthesized based on a semisynthetic route starting from CPT. Most of the synthesized compounds exhibit higher cytotoxic activities on the A-549 tumor cell line than topotecan (TPT). Some compounds such as 2a and 2o show a broad in vitro antitumor spectrum and exhibit superior Topo I-inhibition activity.     

Discriminant analysis. 2. A new index for antitumor activity

The antitumor activities of 17 nitrogen analogs of 1, 4-benzoquinone, expressed in eight different ways, were subjected to discriminant analysis. Different methods of measuring the effectiveness of antitumor agents give different results. Methods based on dose levels such as the optimum dose or the lethal dose appear to be more useful in classifying compounds as antitumor agents than methods based on the maximum antitumor effect. A new index for antitumor activity involving the maximum antitumor effect, the optimum dose, and the therapeutic index, examined by discriminant analysis with substitutive parameters as discriminatory variables, can give valuable information for the design of new antitumor drugs.     

Syntheses and biological evaluation of topoisomerase I-targeting agents related to 11-[2-(N,N-dimethylamino)ethyl]-2,3-dimethoxy-8,9-methylenedioxy-11H-isoquino[4,3-c]cinnolin-12-one (ARC-31)

Several 11-ethyl-2,3-dimethoxy-8,9-methylenedioxy-11H-isoquino[4,3-c]cinnolin-12-ones with varied functionality on the ethyl substituent have exhibited potent topoisomerase I (TOP1) targeting activity and antitumor activity. The influence of various polar substituents at the 2-position of the 11-ethyl substituent, including N-methylamine, N-isopropylamine, hydroxyl, and hydroxylamino groups, on TOP1-targeting activity and cytotoxicity was assessed. The N-methylamine and N-isopropylamine derivatives were also evaluated as antitumor agents in athymic nude mice with MDA-MB-435 human tumor xenografts. Both compounds were active as antitumor agents upon either parenteral or oral administration.     

Determination of the antimutagenicity of an aqueous extract of Rhizophora mangle L. (Rhizophoraceae), using in vivo and in vitro test systems

An aqueous extract of Rhizophora mangle L. bark is used as raw material in pottery making in the State of Espirito Santo, Brazil. This extract presents large quantities of tannins, compounds possessing antioxidant properties. Tannin antioxidant activity, as a plant chemical defense mechanism in the process of stabilizing free radicals, has been an incentive to studies on anti-mutagenicity. The present work aimed to evaluate possible antimutagenic activity of a R. mangle aqueous extract, using the Allium cepa test-system and micronuclear (MN) assay with blockage of cytokinesis in Chinese hamster ovary cells (CHO-K1). The Allium cepa test-system indicated antimutagenic activity against the damage induced by the mutagenic agent methyl methanesulfonate. A reduction in both MN cell frequency and chromosome breaks occurred in both the pre and post-treatment protocols. The MN testing of CHO-K1 cells revealed anti-mutagenic activity of the R. mangle extract against methyl methanesulfonate and doxorubicin in pre, simultaneous and post-treatment protocols. These results suggest the presence of phyto-constituents in the extract presenting demutagenic and bio-antimutagenic activities. Since the chemical constitution of Rhizophora mangle species presents elevated tannin content, it is highly probable that these compounds are the antimutagenic promoters themselves.