Synthesis and comparative molecular field analysis (CoMFA) of antitumor 3-arylisoquinoline derivatives

In this study a series of 3-arylisoquinoline derivatives were synthesized and cytotoxicity against human melanoma tumor cell evaluated, and a three dimensional quantitative structure-activity relationship was investigated using the comparative molecular field analysis (CoMFA). The results suggested that the electrostatic, steric and hydrophobic factors of 3-arylisoquinolines were strongly correlated with the antitumor activity. Considerable predictive ability (cross-validated r2 as high as 0.721) was obtained through CoMFA.     

Comparative molecular field analysis of a series of paclitaxel analogues

A series of 94 paclitaxel analogues exhibiting antitumor activity by promoting the assembly of microtubules and inhibiting the disassembly process of microtubules to tubulin were investigated using the comparative molecular field analysis (CoMFA) method. These compounds belonging to 10 structural classes were randomly divided into a training set of 80 compounds and a test set of 14 compounds. Since the three-dimension structure of ligand--receptor complex is unknown, from X-ray and NMR data we rationally selected the three-dimension structure of paclitaxel in a polar solution as the active conformation and starting structure for molecule modeling, the other molecules were aligned using this molecule model as the template. The most optimal CoMFA yielded a two-components model, with significant cross-validation r2cv of 0.640 and conventional r2 of 0.868. The predictive ability of training set model was tested on the test set of 14 compounds. The tests not only revealed the robustness of the CoMFA model but demonstrated that for our model r2pred based on the mean activity of test set compounds can accurately estimate external predictivity but r2pred based on the mean activity of training set compounds overestimated the model. The CoMFA model explained why the activity of taxoid is sensitive to the stereochemistry of the atoms at C-2' and C-3' positions and the presence of hydroxyl group at C-2' position. The other factors affecting activity were also elucidated according to standard coefficient contour maps of steric and electrostatic fields derived from the CoMFA model.     

In vivo antitumor activity of hexamethylmelamine against human breast, stomach and colon carcinoma xenografts

We have evaluated the antitumor activity of Altretamine (hexamethylmelamine, HMM) on human carcinoma xenografts serially transplanted in nude mice. Five human breast carcinoma xenografts, MX-1, T-61, MCF-7, R-27 and Br-10, were inoculated subcutaneously into female nude mice. Two human stomach carcinoma xenografts, SC-1-NU and St-4, and three human colon carcinoma xenografts, Co-3, Co-4 and Co-6, were inoculated subcutaneously into male nude mice. One pellet of 17 beta-estradiol (0.1 mg/mouse) was inoculated subcutaneously in the mice transplanted with MCF-7 when the tumors were inoculated. HMM was administered per os daily for 4 weeks. MX-1 and T-61 tumors regressed completely after treatment with HMM at a dose of 75 mg/kg (the maximum tolerated dose: MTD) for MX-1 and 25 mg/kg for T-61. Br-10 was sensitive, whereas MCF-7 and R-27 were resistant to HMM at its MTD. HMM exerted the most potent antitumor effect against T-61. Against MX-1, it exerted an antitumor effect equivalent to that of cisplatin or cyclophosphamide. In addition, this agent was effective against all stomach and colon carcinoma xenografts, in particular St-4 (T/C% = 10.7: the mean tumor weight of treated group/the mean tumor weight of control group) and Co-3 (T/C% = 31.5%) which are insensitive to presently available agents. HMM seems worthy of further clinical investigation as a candidate agent to treat breast, stomach, colon and other carcinomas.     

Duodenum-preserving resection of the pancreatic head for mucinous ductal ectasia without overt carcinoma

BACKGROUND/AIMS: The clinical characteristics of mucinous ductal ectasia (MDE) of the pancreas without overt carcinoma have not been clarified. To clarify MDE and assess the optimal treatment procedure, including the technique of duodenum-preserving resection of the pancreatic head (DpRPH), we studied four patients. METHODOLOGY: Our patients consisted of three men and one woman, with a mean age of 71 years. The patients underwent DpRPH (n=3) or the pylorus-preserving Whipple procedure (PpW) (n=1). Clinicopathological features, postoperative pancreatic function, and technique to preserve duodenal blood flow were studied. RESULTS: All patients had intraductal mucin-hypersecretion and multilocular cysts lined by hyperplastic epithelium. The lesions were located in the uncinate process (n=3) or head-body (n=1) of the pancreas. DpRPH totally removed the lesions in the uncinate process. Of the three patients receiving DpRPH, dusky duodenum and a postoperative duodenal ulcer developed in two whose gastroduodenal arteries (GDA) were divided, but did not develop in one with undivided GDA. Postoperative glucose tolerance test and peptide para-aminobenzoic acid test after DpRPH showed better values than those after PpW. All patients are alive and well 22 to 40 months after surgery. CONCLUSIONS: DpRPH is a new standard for MDE. During DpRPH, preservation of the GDA and the superior portion of the pancreatic head is recommended to maintain an adequate duodenal blood flow.     

Comparative molecular field analysis (CoMFA) of a series of symmetrical bis-benzamide cyclic urea derivatives as HIV-1 protease inhibitors

Production of the sex pheromone bombykol in the silkworm, Bombyx mori, is regulated by a neurohormone termed pheromone biosynthesis activating neuropeptide (PBAN). It has been suggested that the external signal of PBAN in this species is transmitted to the intracellular cascade reactions consisting of Ca2+/calmodulin (CaM) complex and phosphoprotein phosphatase. To demonstrate the molecular mechanisms regulated by PBAN, we attempted to characterize CaM in the pheromone gland of B. mori. By using ion-exchange and RP-HPLC, B. mori CaM was purified from the cytosolic fraction of the pheromone gland. The primary structure was deduced by composition/sequence analysis and mass spectrometric analysis of the fragment peptides obtained from enzymatic and chemical fragmentations. The amino acid sequence of B. mori CaM was identical with Drosophila CaM deduced from the CaM gene of D. melanogaster, suggesting that insects have well conserved the molecule of CaM.     

Synthesis and antitumor activity of leinamycin derivatives: modifications of C-8 hydroxy and C-9 keto groups

A series of leinamycin derivatives were synthesized and evaluated for antitumor activity. Modifications at C-8 and C-9 positions revealed a broad structure-activity relationship in vitro and some derivatives showed potent antiproliferative activity against HeLa S3 cells.     

Preclinical antitumor activity of an antibody against the leukocyte antigen CD48

We have evaluated the antitumor activity of a murine antibody (IgG2a) against the leukocyte antigen CD48. CD48 is expressed on T and B lymphocytes, monocytes, and a wide range of lymphoid malignancies. To assess the therapeutic potential of an anti-CD48 antibody, we established a reproducible model of human B-cell (Raji) leukemia/lymphoma in C.B17/scid mice, where untreated mice develop hind leg paralysis due to tumor engraftment. Using this model, the murine anti-CD48 antibody HuLy-m3 was shown to mediate a strong in vivo antitumor effect. Long-term survival (>1 year) of scid mice was obtained after treatment with three 200-microg i.v. doses of anti-CD48 antibody on days 0, 2, and 4 after i.v. injection of tumor cells. In contrast, mice treated with an isotype control antibody developed hind leg paralysis after 34 +/- 3 days. A strong antitumor response was still observed when a dose of 20 microg of HuLy-m3 antibody was used. During preclinical investigations, we also examined a number of properties of the CD48 antigen. CD48 is present at high levels on the surface of T and B cells, but most (>95%) CD34-positive cells do not express CD48. Anti-CD48 antibodies are maintained on the surface of antigen-positive cells for extended periods (>24 h). These properties suggest that anti-CD48 antibodies may be useful in the treatment of a number of diseases including lymphoid leukemias and lymphomas.     

Comparative molecular field analysis of haptens docked to the multispecific antibody IgE(Lb4)

Using comparative molecular field analysis (CoMFA), three-dimensional quantitative structure-activity relationships were developed for 27 haptens which bind to the monoclonal antibody IgE(Lb4). In order to obtain an alignment for these structurally very diverse antigens, the compounds were docked to a previously modeled receptor structure using the automated docking program AUTODOCK (Goodsell, D.S.; Olson, A.J. Proteins: Struct., Funct., Genet. 1990, 8, 195-202). Remarkably, this alignment method yielded highly consistent QSAR models, as indicated by the corresponding cross-validated r2 values (0.809 for a model with carbon as probe atom, 0.773 for a model with hydrogen as probe atom). Conventional alignment failed in providing a basis for self-consistent CoMFAs. Amino acids Tyr H 50, Tyr H 52, and Trp H 95 of the receptor appeared to be of crucial importance for binding of various antigens. These findings are consistent with earlier considerations of aromatic residues being responsible for the multispecificity of certain immunoglobulins.     

Comparative molecular field analysis of non-steroidal aromatase inhibitors: an extended model for two different structural classes

Aromatase is a cytochrome P450 isozyme, whose inhibition is known to be therapeutically relevant in the treatment of the breast cancer. A comparative molecular field analysis (CoMFA) has been carried out on a series of non-steroidal aromatase inhibitors belonging to two different structural classes. One subset of compounds consists of fadrozole analogues and was studied in a previous work, from which a 'local' 3-D quantitative structure-activity relationship (QSAR) model for the inhibition of aromatase was obtained. In the present paper, that model is extended to include a second subset of compounds bearing a tetralone nucleus and acting at the same enzyme site with the same mechanism as the azoles. The critical alignment step has been solved by using two different steroidal inhibitors of aromatase as rigid templates, on which the non-steroidal compounds have been superimposed. The final 3-D QSAR models are discussed in terms of predictivity and some implications regarding the steric and electronic requirements of steroidal and non-steroidal inhibitors are pointed out.     

Comparative study of carbohydrate antigen 195 and carcinoembryonic antigen for the diagnosis of pancreatic carcinoma

The expression CA195 in serum, defined by monoclonal antibody CC3C195 (IgM), was studied in 67 patients with pancreatic cancer and in 138 patients with biliary or pancreatic benign disease. The results were compared with carcinoembryonic antigen (CEA) expression. The overall sensitivity of the CA195 assay (> 12 U/ml) was higher than that for CEA (89.5% vs. 53.7%) (p < 0.001). Sensitivity was increased to 92.5% with the simultaneous use of the two antigens, but the difference was statistically significant only with CEA (p < 0.001). The specificity of CA195 calculated from all patients with benign diseases was lower than that of CEA (73.1% vs. 89.8%). However, using a cutoff value of 100 U/ml for CA195, the specificity of this antigen (82%) was higher than that of CEA. These results demonstrate that marked elevations of tumor antigen CA195 are relatively specific for pancreatic carcinoma, and that this antigen is superior to CEA for diagnosing pancreatic cancer by virtue of its higher sensitivity.     

Cationic trypsinogen produced by human pancreatic ductal cancer has the characteristics of spontaneous activation and gelatinolytic activity in the presence of proton

Exposure to an open field has been shown to cause a rise in the body temperature of rats. In many respects, this rise in body temperature is similar to fevers caused by endotoxin and other inflammatory stimuli. Rats repeatedly injected with endotoxin develop tolerance to the fever-inducing action of endotoxin. We hypothesized that repeated pretreatment with endotoxin would modify the fever caused by exposure to psychological stress. To test this hypothesis, we compared open field-induced fevers in rats made endotoxin tolerant to those rats not endotoxin tolerant. We found that endotoxin tolerance had no effect on open field fevers.     

Comparative genomic hybridisation of ductal carcinoma in situ of the breast: identification of regions of DNA amplification and deletion in common with invasive breast carcinoma

Comparative genomic hybridisation has been used to map copy number changes in nine cases of ductal carcinoma in situ of the breast obtained from wax-embedded archive material. A wide variety of abnormalities were detected including gain of regions of 1q, 17q, 19q, 20p and 20q and loss on 13q, 14q, 17p, 16q and 22q. Amplification of areas on 10p, 8q and 20q were also observed. Chromosomal alterations were more frequent in higher grade DCIS and closely resemble those previously detected in invasive breast cancer using the same technique. These data provide strong molecular support for the view that DCIS is a precursor lesion of invasive breast carcinoma.     

Structure-activity relationships of the antimalarial agent artemisinin. 1. Synthesis and comparative molecular field analysis of C-9 analogs of artemisinin and 10-deoxoartemisinin

A series of C-9 beta-substituted artemisinin analogs (2-21) were synthesized via dianion alkylation of the total synthetic intermediate 57 followed by subsequent ozonolysis/acidification, or by alkylation of the enolate derived from (+)-9-desmethylartemisinin, 2. Inactive acyclic analogs 22 and 23 were synthesized by nucleophilic epoxide opening and the ring contracted analog 24 was prepared by an alternate route. 10-Deoxo-9-alkyl derivatives 68 and 70 were synthesized convergently from intermediates in the preparation of 9-alkyl derivatives. In vitro bioassay was conducted in W-2 and D-6 clones of drug resistant Plasmodium falciparum. Comparative molecular field analysis (CoMFA) of the 9-alkyl lactone derivatives provided a model with a cross-validated r2 = 0.793. Inclusion of inactive 1-deoxyartemisinin analogs 26-42 provided a model with a value of 0.857. The activities of a number of other analogs of divergent structure (43-56) were predicted with good accuracy using the CoMFA model.     

Stable reintroduction of wild-type P53 (MTmp53ts) causes the induction of apoptosis and neuroendocrine-like differentiation in human ductal pancreatic carcinoma cells

Pancreatic ductal adenocarcinoma is one of the major causes of cancer mortality in the industrialized world, having among the poorest prognosis of any malignancy. Mutations or alterations in the p53 tumor suppressor gene/protein are observed in 50-70% of these cancers, yet little information is available regarding the phenotypic effects of restoration of wild-type (wt) p53 function in pancreatic ductal carcinoma cells. The consequences of stable reintroduction of wt p53 on apoptosis and differentiation was examined in a poorly differentiated pancreatic carcinoma cell line (Panc-1), possessing only mutant (mt) p53 (codon 273 mutation). Cells were transfected with a temperature-sensitive mouse p53val135 (tsp53) vector under additional control of a genetically-modified metallothionein promoter. This tsp53 has a 'mt' phenotype at 37.5 degrees C, and a 'wt' phenotype at 32.5 degrees C and the presence of 100 microM ZnCl2. Stable expression of wt p53 caused upregulation of the p21/WAF1 gene, and G1 growth arrest as shown by flow cytometry and BrdU labeling. Additionally, apoptosis was induced 8-12 post-induction in the majority of the cells (60-70%), as demonstrated by morphological changes, in situ TdT labeling and internucleosomal laddering. However, a subpopulation (30%) of the transfectants survived this apoptotic fate. Unlike the epithelial parental Panc-1 cells, these cells exhibited the appearance of a neuroendocrine-like phenotype with extensive branch-like processes, and marked cytoplasmic and cytoskeletal immunostaining for tau-2, synaptophysin, and chromogranin A. These studies suggest that stable and regulated expression of wt p53 can have multiple phenotypic consequences (apoptosis and altered differentiation to a neuroendocrine-like phenotype) in poorly-differentiated pancreatic carcinoma cells.     

Relationships between the anthelmintic activity of eight derivatives of benzimidazole carbamates against Trichinella spiralis and their chemical structures

Efficacy of eight recently developed and used anthelmintics of the benzimidazole carbamates; mebendazole, flubendazole, oxfendazole, albendazole, oxibendazole, 790163 proflubendazole, 780118 "cyanide" benzimidazole and 780120 "selenium" benzimidazole was tested orally against the enteral immature larval and adult stages of Trichinella spiralis in mice. Six of these derivatives of methyl benzimidazole-2-carbamates have an aryl and two have an alkyl substituent at the 5'-position of the parent benzimidazole ring. The nature of these substituents was found to be related to the antitrichinellous activity of the compounds. Compounds with the 5'-substituent linked to the parent benzimidazole ring by either a carbon, sulfur or an oxygen atom are more potent than those bridged by selenium or by the carbon with an attached-CN group. The result clearly indicates that the benzimidazoles are invariably more potent against immature enteral phase than the adult worms. This finding would be of importance in a targeted synthesis of new, effective derivatives of benzimidazole, e.g., in the screening for more important tissue-dwelling nematodes like filarial worms.     

Endogenous tumor necrosis factor functions as a resistant factor against hyperthermic cytotoxicity in pancreatic carcinoma cells via enhancement of the heart shock element-binding activity of heart shock factor 1

Airway resistance was measured by the interrupter technique in 54 children [aged 63.8 months (range: 9.1-131.6 months)], with perinatal human immunodeficiency virus-type 1 (HIV-1) infection and in a control group of 315 gender, height, and race-matched healthy children. In addition, 14 HIV-infected children, aged 75-131 months, had spirometry performed. Resistance was significantly higher in infected children than in controls (0.84 +/- 0.3 vs 0.64 +/- 0.08 kPa x l(-1) x s; t = 9.991; P < 0.0001). Resistance decreased with age in controls (r = -0.95; P < 0.001), but not in infected children (r= -0.22; P = 0.105). Resistance did not correlate with mothers' intravenous drug addiction, perinatal data, T-cell subset numbers, treatment, clinical course, or presence of respiratory complications. Resistance was higher (t = 3.103; P < 0.003) in p24 antigen-positive than in negative children. Thirty-nine children underwent a second evaluation 12.3 months (range 11.1-14 months) after the first. Resistance was higher (t = 3.960; P < 0.0001) at the second evaluation compared to the first. Eight of 14 children had abnormal spirometric measurements. We conclude that perinatal HIV-1 infection is associated with increased airway resistance and often abnormal spirometry. The degree of abnormalities in resistance depends on the duration of the infection rather than on HIV-1-related respiratory complications.