|ognizant Communication Corporation|
AN INTERNATIONAL JOURNAL
INCORPORATING ANTI-CANCER DRUG DESIGN
VOLUME 16, NUMBER 3
Oncology Research, Vol. 16, pp. 107-118
0965-0407/06 $90.00 + .00
Copyright © 2006 Cognizant Comm. Corp.
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In Vitro and In Vivo Evaluation of Two Rational-Designed Nonpeptidic Farnesyltransferase Inhibitors on HT29 Human Colon Cancer Cell Lines
Nicolas Wlodarczyk,1 Pauline Gilleron,1 Régis Millet,1 Raymond Houssin,1 Jean-François Goossens,1 Amélie Lemoine,1 Nicole Pommery,1 Ming X. Wei,2 and Jean-Pierre Hénichart1
1Institut de Chimie Pharmaceutique Albert Lespagnol, EA 2692,
Université de Lille 2, BP 83, 3 rue du Professeur Laguesse, 59006
2Cellvax, Parc Eurasanté, 180 avenue Eugène Avinée, 59120 Loos, France
FTase inhibitors constitute a new class of potential cancer therapeutics, especially in colorectal cancer where K-ras-selective mutations exist and have a role in tumorigenesis. The synthesis and biological evaluation of two nonpeptidic molecules (13 and 16) designed on the basis of a zinc chelator imidazole linked to two aromatic fragments able to fit in the "exit groove" and in the "A2 binding site" of FTase are described. These molecules are characterized respectively by a flexible phenylmethyl chain and a more constrained scaffold so as to evaluate their respective influences on site recognition. They have been evaluated in vitro and in vivo against human colon cancer cell lines and 13 not only inhibited tumor growth but also showed no toxic effects at the dose used.
Key words: Farnesyltransferase inhibitors; Ras; Colon cancer
Address correspondence to Jean-Pierre Hénichart, Institut de Chimie Pharmaceutique Albert Lespagnol, Université de Lille 2, BP 83, 59006 Lille, France. Tel: 33 3 20 96 43 74; Fax: 33 3 20 96 49 06; E-mail: email@example.com
Pu-erh Tea Supplementation Suppresses Fatty Acid Synthase Expression in the Rat Liver Through Downregulating Akt and JNK Signalings as Demonstrated in Human Hepatoma HepG2 Cells
Chun-Te Chiang,1 Meng-Shih Weng,1 Shoei-Yn Lin-Shiau,2 Kuan-Li Kuo,3 Yao-Jen Tsai,3 and Jen-Kun Lin1
1Institute of Biochemistry and Molecular Biology, College
of Medicine National Taiwan University, Taipei, Taiwan
2Institute of Pharmacology, College of Medicine National Taiwan University, Taipei, Taiwan
33Wun-Shan Branch, Tea Research and Extension Station, Taipei, Taiwan
Fatty acid synthase (FAS) is a key enzyme of lipogenesis. Overexpression of FAS is dominant in cancer cells and proliferative tissues. The expression of FAS in the livers of rats fed pu-erh tea leaves was significantly suppressed. The gains in body weight, levels of triacylglycerol, and total cholesterol were also suppressed in the tea-treated rats. FAS expression in hepatoma HepG2 cells was suppressed by the extracts of pu-erh tea at both the protein and mRNA levels. FAS expression in HepG2 cells was strongly inhibited by PI3K inhibitor LY294002 and JNK inhibitor II and slightly inhibited by p38 inhibitor SB203580 and MEK inhibitor PD98059, separately. Based on these findings, we suggest that the suppression of FAS in the livers of rats fed pu-erh tea leaves may occur through downregulation of the PI3K/AKt and JNK signaling pathways. The major components of tea that have been demonstrated to be responsible for the antiobesity and hypolipidemic effects are catechins, caffeine, and theanine. The compositions of catechins, caffeine, and theanine varied dramatically in pu-erh, black, oolong, and green teas. The active principles and molecular mechanisms that exerted these biological effects in pu-erh tea deserve future exploration.
Key words: Fatty acid synthase (FAS); HepG2 cells; Pu-erh tea; Black tea; Oolong tea; Green tea; Akt signaling; JNK signaling; Anticancer; Antiobesity
Address correspondence to Dr. Jen-Kun Lin, Institute of Biochemistry and Molecular Biology, College of Medicine National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, Taiwan. Tel: (886)-2-2356-2213; Fax: (886)-2-2391-8944; E-mail: JKLin@ha.mc.ntu.edu.tw
The Effect of an Estrone D-Lactam Steroid Ester Derivative on Breast Cancer Cells and Its Predicted Binding Interactions With the Ligand Binding Domain of Estrogen Receptor-a
Michael Kontos,1 Marilena Nikolopoulou,1 Dimitrios T. P. Trafalis,2,3 George D. Geromichalos,4 Catherine Koukoulitsa,5 Charalambos Camoutsis,2 Elias Bastounis,1 and Panayiotis Karamanakos1
11st Department of Surgery, University of Athens, Laiko General
Hospital, Athens, Greece
2Lab of Medicinal Chemistry, Department of Pharmacy, University of Patras, Patras, Greece
31st Department of Medical Oncology, "Metaxa" Cancer Hospital, Piraeus, Greece
4Department of Cell Culture-Molecular Modeling & Drug Design, Symeonidio Research Center, Theagenio Cancer Hospital, Thessaloniki, Greece
5Department of Pharmacognosy & Chemistry of Natural Products, School of Pharmacy, University of Athens, Athens, Greece
In order to further improve the toxicity profile and the anticancer effect of chlorambucil (CBL), we have synthesized a new estrone D-lactam steroidal ester of CBL (ESBL). The aim of this study was to investigate the in vitro activity of ESBL against primary breast carcinoma (BC) cells of operable tumors in comparison with CBL. Cells derived from fresh tumor sections that were obtained from 28 postmenopausal women with ductal BC were treated with CBL and ESBL. Apoptotic cells were distinguished from viable ones with flow cytometric methods. ESBL generated a significantly higher rate of cell apoptosis and cytotoxicity than CBL. ESBL cytotoxic effect demonstrated a significant positive weak to moderate dose-dependent correlation with the ER expression. ESBL produced antineoplastic activity superior to CBL on primary BC tumors in vitro. Moreover, a docking study on the binding interactions of ESBL with the ligand binding domain (LBD) of estrogen receptor-a (ERa) was investigated. ESBL was found to be positioned inside the binding cavity with its steroidal moiety, whereas the alkylating moiety protruded out of receptor's pocket.
Key words: Breast cancer; Chlorambucil; Docking; Estrogen receptor; Flow cytometry; Homo-aza-steroid alkylating esters
Address correspondence to Dimitrios Trafalis, Ph.D., M.D., 15 Larnakos, 17341 Agios Dimitrios, Athens, Greece. Tel: +30 210 971 5465; Fax: +30 210 971 3766; E-mail: firstname.lastname@example.org and/or email@example.com
Molecular Characterization of Established Human Colon Carcinoma Cell Lines (HCT-8) Made Resistant to 5-Fluorouracil by Different Selection Schedules
Alessio Tempestini,1 Barbara Caciagli,2 Maria Morganti,2 Ewa Witort,1 Stefania Nobili,2 Laura Papucci,1 Nicola Schiavone,1 Martino Donnini,1 Ida Landini,2 Andrea Lapucci,1 Federico Perna,1 Matteo Lulli,1 Teresita Mazzei,2 Alberto Sobrero,3 Enrico Mini,2 and Sergio Capaccioli1
1Department of Experimental Pathology and Oncology, University
of Florence, Florence, Italy
2Department of Preclinical and Clinical Pharmacology, University of Florence, Florence, Italy
3Section of Medical Oncology, Ospedale S. Martino, Genoa, Italy
To provide some insight into molecular mechanisms of 5 fluorouracil (5-FU) clinical resistance in colorectal cancer, we hypothesized that different in vitro exposure schedules of human colorectal cancer cell lines mimicking clinical infusion or bolus regimens could lead to differential gene expression. Resistant HCT-8 colon cancer cell lines (HCT-8/FUI/15R and HCT-8/FUB/2R) were selected from parental sensitive HCT-8 cells by long-term and short-term exposure schedules, respectively. Expression levels of the 437 genes evaluated by the Atlas Select cDNA Expression Human Tumor Array were not substantially different between HCT-8/FUB/2R and HCT-8 cell lines except for three genes downregulated in the resistant subline. Several genes were differentially expressed in HCT-8/FUI/15R cells compared to the parental cell line: 43 genes, including three chemoresistance-related genes, were upregulated, and three genes were downregulated. HCT-8/FUB/2R cells were substantially more resistant to 5-FU in comparison to HCT-8/FUI/15R cells after both 4- and 72-h exposures. No substantial differences were observed among resistant and parental cells in sensitivity to SN-38, the active metabolite of irinotecan, and oxaliplatin. Analysis of the mRNA levels of thymidylate synthase, thymidine phosphorylase, and bcl-2 genes evaluated by reverse transcription and real time PCR (RT-PCR) assay showed comparable results in resistant sublines and sensitive parental cells, whereas expression of the dihydropyrimidine dehydrogenase gene was markedly increased in both resistant cell lines compared to parental cells.
Key words: 5-Fluorouracil; Drug resistance; Gene expression; Colon carcinoma; Tumor cell lines; Drug administration schedule
Address correspondence to Enrico Mini, M.D., Ph.D., Professor of Chemotherapy, Department of Preclinical and Clinical Pharmacology, University of Florence, V.le Pieraccini, 6, 50139 Florence, Italy. Tel: +39-55-4271305-306; Fax: +39-55-4271306; E-mail: firstname.lastname@example.org
In Vitro Inhibition of Promyelocytic Leukemia/Retinoic Acid Receptor-a (PML/RARa) Expression and Leukemogenic Activity by DNA/LNA Chimeric Antisense Oligos
Sara Caprodossi,1,2 Luca Galluzzi,1 Simona Biagetti,1 Giulia Della Chiara,1 Pier Giuseppe Pelicci,2,3 Mauro Magnani,1 and Mirco Fanelli1
1Centre of Biotechnology, University of Urbino, 61032 Fano,
2Department of Experimental Oncology, European Institute of Oncology, 20141 Milan, Italy
3FIRC Institute for Molecular Oncology (IFOM), 20139 Milan, Italy
Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by the chromosomal translocation t(15:17) that leads to the expression of promyelocytic leukemia/retinoic acid receptor-a (PML/RARa) oncofusion protein. The block of differentiation at the promyelocytic stage of the blasts and their increased survival induced by PML/RARa are the principal biological features of the disease. Therapies based on pharmacological doses of retinoic acid (RA, 10-6 M) are able to restore APL cell differentiation in most cases, but not to achieve complete hematological remission because retinoic acid resistance occurs in many patients. In order to elaborate alternative therapeutic approaches, we focused our attention on the use of antisense oligonucleotides as gene-specific drug directed to PML/RARa mRNA target. We used antisense molecules containing multiple locked nucleic acid (LNA) modifications. The LNAs are nucleotide analogues that are able to form duplexes with complementary DNA or RNA sequences with highly increased thermal stability and are resistant to 3´-exonuclease degradation in vitro. The DNA/LNA chimeric molecules were designed on the fusion sequence of PML and RARa genes to specifically target the oncofusion protein. Cell-free and in vitro experiments using U937-PR9-inducible cell line showed that DNA/LNA oligonucleotides were able to interfere with PML/RARa expression more efficiently than the corresponding unmodified DNA oligo. Moreover, the treatment of U937-PR9 cells with these chimeric antisense molecules was able to abrogate the block of differentiation induced by PML/RARa oncoprotein. These data suggest a possible application of oligonucleotides containing LNA in an antisense therapeutic strategy for APL.
Key words: Antisense oligo; Acute promyelocytic leukemia; PML/RARa; Locked nucleic acid
Address correspondence to Mirco Fanelli, Centre of Biotechnology,
University of Urbino "Carlo Bo," Via Campanella 1, 61032 Fano (PU), Italy.
Tel: +39-0721-862832; Fax: +39-0721-862834; E-mail: email@example.com