Design, synthesis, and DNA-binding of N-alkyl(anilino)quinazoline derivatives

New N-alkylanilinoquinazoline derivatives 5, 12, 20, and 22 have been prepared from 4-chloro-6,7-dimethoxyquinazoline 3, 4-chloro-6,7-methylenedioxyquinazoline 19, and commercially available anilines. Differents classes of compounds substituted by an aryloxygroup (6a-c, 16a,b, and 17a,b), (aminophenyl)ureas (12a,b and 13a-f), anilines (4a-m, 20a,b), N-alkyl(aniline) (5a-m, 21a,b, 22a,d), and N-aminoalkyl(aniline) (22e-g) have been synthesized. These molecules were evaluated for their cytotoxic activities and as potential DNA intercalating agents. We studied the strength and mode of binding to DNA of these molecules by DNA melting temperature measurements, fluorescence emission, and circular dichroism. The results of various spectral and gel electrophoresis techniques obtained with the different compounds, in particular compounds 5g and 22f, revealed significant DNA interaction. These experiments confirm that the N-aminoalkyl(anilino)-6,7-dimethoxyquinazoline nucleus is an efficient pharmacophore to trigger binding to DNA, via an intercalative binding process.

Progression of alphafetoprotein before liver transplantation for hepatocellular carcinoma in cirrhotic patients: a critical factor

Liver transplantation (LT) for cirrhotic/Hepatocellular carcinoma (HCC) is associated with reduced survival in patients with poor histological features. Preoperative levels of alphafetoprotein (AFP) could predict negative biological features. AFP progression could be more relevant than static AFP levels in predicting LT outcomes. A total of 252 cirrhotic/HCC patients transplanted between 1985 and 2005 were reviewed. One hundred fifty-three patients were analyzed, 99 excluded (for nonsecreting tumors and/or salvage transplantation). Using receiver operating characteristics analysis for recurrence after LT, 'progression' of AFP was defined by >15 microg/L per month before LT. A total of 127 (83%) were transplanted under and 26 (16%) over this threshold. After 45 months of follow-up (median), 5-year overall survival (OS) and recurrence free-survival (RFS) were 72% and 69%, respectively. Five-year survival in the progression group was lower than the nonprogression group (OS 54% vs. 77%; RFS 47% vs. 74%). Multivariate analysis showed progression of AFP>15 microg/L per month and preoperative nodules>3 were associated with decreased OS. Progression group and age>60 years were associated with decreased RFS. Male gender, progression of AFP and size of tumor>30 mm were associated with satellite nodules and/or vascular invasion. In conclusion, increasing AFP>15 microg/L/month while waiting for LT is the most relevant preoperative prognostic factor for low OS/DFS. AFP progression could be a pathological preoperative marker of tumor aggressiveness.

The cis-regulatory sequences required for expression of the Drosophila melanogaster adult cuticle gene ACP65A

Post-embryonic development in insects requires successive molts. Molts are triggered by ecdysteroids, and the nature of the molt (larval, pupal or adult) is determined by juvenile hormones. The genes encoding cuticle proteins are targets of both classes of hormones, and therefore are interesting models to study hormone action at the molecular level. The Drosophila ACP65A cuticle gene is expressed exclusively during the synthesis of the adult exoskeleton, in epidermal domains synthesising flexible cuticle. We have examined the cis-regulatory sequences of ACP65A using phylogenetic comparisons and functional analysis, and find that only about 180 bp are essential, including an 81 bp intron. The restriction of ACP65A expression appears to depend on a strong repression mechanism.

Derivatives of Iressa, a specific epidermal growth factor receptor inhibitor, are powerful apoptosis inducers in PC3 prostatic cancer cells

The tyrosine kinase activity of the epidermal growth factor receptor (EGFR) is widely involved in signaling pathways and often deregulated in cancer. Its role in the development of prostate cancer is well established, and therapeutic strategies such as blockade of the intracellular tyrosine kinase domain with small-molecule tyrosine kinase inhibitors have been proposed. Herein we describe the synthesis and in vitro pharmacological properties of C6- and C7-substituted 4-anilinoquinazolines, analogues of Iressa and powerful proapoptotic inducers in hormone-independent prostate cancer PC3 cell lines.

Design, synthesis and biological evaluation of substituted dioxodibenzothiazepines and dibenzocycloheptanes as farnesyltransferase inhibitors

A new series of FTase inhibitors containing a tricyclic moiety--dioxodibenzothiazepine or dibenzocycloheptane--has been designed and synthesized. Among them, dioxodibenzothiazepine 18d displayed significant inhibitory FTase activity (IC(50)=17.3 nM) and antiproliferative properties.

Stage III colon cancer prognosis prediction by gene expression profiling

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Background and Aims: Postoperative chemotherapy has become part of the standard treatment for stage III colon cancer patients. Since approximately half of patients are cured by surgery alone, adjuvant chemotherapy should not be used in all patients. This study aimed to assess the possibility to use microarray-based gene expression profiles to predict the prognosis of stage III colon cancer patients. Material and Methods: Forty-two patients operated on for a stage III colon cancer were included in this study. Twenty-one patients have received an adjuvant chemotherapy, while the other 21 have received no treatment. Twenty patients have developed a liver metastasis, while the other 22 have remained disease-free for at least 5 years. Tumor mRNA samples were profiled using the Affymetrix HGU133A GeneChip. Two analyses were performed: one with the 42 patients, the other with the 21 patients who did not receive any adjuvant chemotherapy. For each analysis, patients were repeatedly and randomly divided into 10,000 training (TS) and validation sets (VS) of 10 different sizes. For each TS/VS split, a 30-gene prognosis predictor (PP), identified on the TS, was used to predict the prognosis of VS patients. Performances of a 15-gene PP and a 34-gene PP, proposed by another research team, were also assessed on the same TS and VS. Results: First analysis (42 patients). The 10,000 30-gene PP yielded the following average prognosis prediction performance measures: 73.8% accuracy, 74.6% sensitivity, and 73.0% specificity. Improvements in prognosis prediction were observed with increasing TS size. A total of 4,446 genes were included in the 10,000 PP. The 15-gene PP yielded a 69.7% accuracy; the 34-gene PP yielded a 71.2% accuracy. Second analysis (21 patients). The 10,000 30-gene PP yielded the following average prognosis prediction performance measures: 77.7% accuracy, 75.8% sensitivity, and 79.9% specificity. Improvements in prognosis prediction were observed with increasing TS size. A total of 5,478 genes were included in the 10,000 PP. The 15-gene PP yielded a 78.5% accuracy; the 34-gene PP yielded a 81.9% accuracy. Conclusion: Microarray gene expression profiling is able to predict the prognosis of stage III colon cancer patients and, thus, might be used for an appropriate use of adjuvant chemotherapy.

No significant financial relationships to disclose.

EGFR is frequently hyperexpressed in human malignant peripheral nerve sheath tumors (MPNST) and is preferentially localized in high grade areas

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Background: MPNST are highly malignant Schwann cell neoplasms that are generally resistant to conventional radiation and chemotherapy. Mouse models and in vitro data suggest that epidermal growth factor receptor (EGFR) expression is implicated in malignant transformation of Schwann cells. Methods: MPNST samples from 52 patients were studied for EGFR, Ki67, neurofibromin, p53 and survivin expression by immunohistochemistry and for EGFR amplification by in situ hybridization. Results were correlated with clinical data. EGFR RNA were also quantified by RT-PCR in 20 other MPNST and 14 cutaneous neurofibroma samples. Results: Half of the patients had a neurofibromatosis type 1 (NF1), and their age was lower at diagnosis (19 versus 27 years, P=0.04). EGFR expression was detected in 86% of MPNST, and was more frequent in NF1 (95% versus 75%). The staining of tumor cells was heterogeneous in several cases, and closely associated with high grade, Ki67 high and p53 positive areas. MPNST expressed a higher level of EGFR transcripts than neurofibromas. The five year survival was 33%, and NF1 status was the only prognostic factor in multivariate analysis. Conclusion: Our data suggest that EGFR may become a target for new therapies in MPNST, in particular in NF1-associated MPNSTs.

No significant financial relationships to disclose.

In vitro and in vivo evaluation of two rational-designed nonpeptidic farnesyltransferase inhibitors on HT29 human colon cancer cell lines

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.

Prognosis of stage II colon cancer by non-neoplastic mucosa gene expression profiling

We have assessed the possibility to build a prognosis predictor (PP), based on non-neoplastic mucosa microarray gene expression measures, for stage II colon cancer patients. Non-neoplastic colonic mucosa mRNA samples from 24 patients (10 with a metachronous metastasis, 14 with no recurrence) were profiled using the Affymetrix HGU133A GeneChip. Patients were repeatedly and randomly divided into 1000 training sets (TSs) of size 16 and validation sets (VS) of size 8. For each TS/VS split, a 70-gene PP, identified on the TS by selecting the 70 most differentially expressed genes and applying diagonal linear discriminant analysis, was used to predict the prognoses of VS patients. Mean prognosis prediction performances of the 70-gene PP were 81.8% for accuracy, 73.0% for sensitivity and 87.1% for specificity. Informative genes suggested branching signal-transduction pathways with possible extensive networks between individual pathways. They also included genes coding for proteins involved in immune surveillance. In conclusion, our study suggests that one can build an accurate PP for stage II colon cancer patients, based on non-neoplastic mucosa microarray gene expression measures.

Co expression of SCF and KIT in gastrointestinal stromal tumours (GISTs) suggests an autocrine/paracrine mechanism

KIT is a tyrosine kinase receptor expressed by several tumours, which has for specific ligand the stem cell factor (SCF). KIT is the main oncogene in gastrointestinal stromal tumours (GISTs), and gain-of-function KIT mutations are present in 70% of these tumours. The aim of the study was to measure and investigate the mechanisms of KIT activation in 80 KIT-positive GIST patients. KIT activation was quantified by detecting phosphotyrosine residues in Western blotting. SCF production was determined by reverse transcriptase-PCR, ELISA and/or immunohistochemistry. Primary cultures established from three GISTs were also analysed. The results show that KIT activation was detected in all cases, even in absence of KIT mutations. The fraction of activated KIT was not correlated with the mutational status of GISTs. Membrane and soluble isoforms of SCF mRNA were present in all GISTs analysed. Additionally, SCF was also detected in up to 93% of GISTs, and seen to be present within GIST cells. Likewise, the two SCF mRNA isoforms were found to be expressed in GIST-derived primary cultures. Thus, KIT activation in GISTs may in part result from the presence of SCF within the tumours.

Prognosis prediction of stage II colon cancer by gene expression profiling

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Background: The aims of the present study were: 1) to identify a prognosis signature (PS), based on microarray gene expression measures, in stage II colon cancer patients and to assess its accuracy with resampling techniques ; 2) to assess the accuracy, also with resampling techniques, of a previously proposed 23-gene PS. Methods: Colon tumor mRNA samples from 50 patients were profiled using the Affymetrix HGU133A GeneChip (22283 sequences). In a first part, the 50 patients were randomly divided into 2 groups (G1 and G2) of equal size that were considered alternately as training and validation sets. In a second part, the 50 patients were randomly divided into 1600 training (size=n) and validation (size=50-n) sets. Informative genes were selected on the training set by taking the 30 most differentially expressed genes between patients who recurred and those who remained disease-free; the accuracy of this PS was assessed by comparing the predicted prognosis (using a diagonal linear discriminant analysis (DLDA)) and the actual evolution for all the validation set patients. Using the same random splits, the accuracy of the 23-gene PS was assessed with a DLDA that used learning set patients as reference samples. Results: The 30-gene PS that was identified from G1 (G2) patients yielded a 80% (84%) prognosis prediction accuracy when applied on G2 (G1) patients. With resampling techniques, the prediction accuracy regularly increased with the learning set (LS) size: 65.5% (range=52.5–75%) with LS of size 10, and 82.7% (range=60–100%) with LS of size 40. Comparisons of compositions of the 100 PS for a given value of n suggested a high instability of informative genes; with LS of size 10, 7 genes were part of at least 10% of signatures; with LS of size 40, 7 genes were part of all the 100 signatures. The accuracy of the previously proposed 23-gene PS also increased with the learning set size. Conclusion: Microarray gene expression profiling represents a promising technique to predict the prognosis of stage II colon cancer patients. The present study also outlines the high instability of informative gene selection and suggests the usefulness of resampling techniques to obtain an honest assessment of prognosis prediction accuracy.

No significant financial relationships to disclose.

Solid-phase synthesis and pharmacological evaluation of a library of peptidomimetics as potential farnesyltransferase inhibitors: an approach to new lead compounds

Oncogenic Ras proteins whose activation is farnesylation by farnesyltransferase have been seen as important targets for novel anticancer drugs. Inhibitors of this enzyme have already been developed as potential anti-cancer drugs, particularly by rational design based on the structure of the CA(1)A(2)X carboxyl terminus of Ras. Synthesis of a peptidomimetics library via solid-phase synthesis using the Multipin method is described here. The most active hits on cellular assays were resynthesized and enzymatic activity was measured. Compounds A1, A5 and A7 present significant activity on the isolated enzyme (IC(50)=117, 57.3 and 28.5 nM) and their molecular docking in the active site of the enzyme provides details on key interactions with the protein.

Fate and characterization of circulating tumor cells in a NOD/SCID mouse model of human hepatocellular carcinoma

There is much debate about the way in which epithelial tumors metastasize. It has been proposed that the bone marrow (BM) acts as a tumor cell reservoir. We injected human hepatocellular carcinoma (HCC) cells (Mahlavu cell line) into the livers, circulation or BM of NOD/SCID mice and circulating tumor cells were quantified. When injected under the Glisson capsule, a primary tumor developed and continuously yielded circulating tumor cells. Liver tumor removal led to a very low level of Mahlavu cells both in blood and BM 30 days later. When Mahlavu cells (cultured or from BM of primary mice femurs) were intravenously injected into mice, the number of cells in the bloodstream (BS) steadily decreased, whereas the BM was not significantly colonized. When Mahlavu cells were directly injected into one femur, the controlateral femur was not colonized. Microscopic analysis and a sensitive PCR assay (<1 Mahlavu cell/nuclear cells) both failed to detect human tumor cells in other organs regardless of injection route. In conclusion, our model strongly supports the hypothesis that HCCs continuously release cells into the BS. However, in sharp contrast with the current hypothesis, the BM is not specifically colonized by tumor cells but could store them at a very low level.

Novel N-(4-Piperidinyl)benzamide Antimalarials with Mammalian Protein Farnesyltransferase Inhibitory Activity

Protein farnesyltransferase of Plasmodium falciparum is a potential target in the treatment of malaria for which increased drug resistance is observed. The design, synthesis and evaluation of a series of N-(4-piperidinyl)benzamides is reported. The most potent compounds showed in vitro activity against the parasite at submicromolar concentrations.