Malek Zihlif

Gene expression alterations in doxorubicin resistant MCF7 breast cancer cell line

Many molecular mechanisms contribute to the development of doxorubicin resistance and different cancers can express wide and diverse arrays of drug-resistance genes. The aim of this study was to identify the changes in gene expression associated with the development of doxorubicin resistance in MCF7 breast cancer cell line. The doxorubicin resistant MCF7 cell line was developed by stepwise selection of MCF7 cells and was tested using the MTT assay. The alterations in gene expression were examined using the real-time based PCR array. The findings showed an up-regulation of many phase I/II metabolizing genes, specifically, the CYP1A1 and the CYP1A2 that were up-regulated by 206- and 96-fold respectively. Drug efflux pump genes were also up-regulated profoundly. TOP2A was strongly down-regulated by 202-fold. Many other changes were observed in genes crucial for cell cycle, apoptosis and DNA repair. The findings of this project imply that the development of doxorubicin resistance is a multi-factorial process.

Synthesis, and antitumor activity of some N1-(coumarin-7-yl) amidrazones and related congeners.

A series of new N1-(coumarin-7-yl)amidrazones incorporating N-piperazines and related congeners were synthesized by reacting the hydrazonoyl chloride derived from 7-amino-4-methylcoumarin with the appropriate piperazines. The chemical structures of the newly prepared compounds were supported by elemental analyses, 1H-NMR, 13C-NMR, and ESI-HRMS spectral data. The antitumor activity of the newly synthesized compounds was evaluated. Among all the compounds tested, 7-{2-[1-(4-(1-benzyl-2-ethyl-4-nitro-1H-imidazol-5-yl)piperazin-1-yl)-2-oxopropylidene]hydrazinyl}-4-methyl-2H-chromen-2-one (3n) was the most potent against MCF-7 and K562 cells, with IC50 values of 20.2 and 9.3 μM, respectively.

β-Caryophyllene causes regression of endometrial implants in a rat model of endometriosis without affecting fertility.

Many studies have shown that anti-inflammatory agents are effective in the treatment of endometriosis. β-Caryophyllene exerted a potent anti-inflammatory effect in vivo. However, its effect on endometriosis has not been investigated. This study aims at investigating the effect of β-caryophyllene on endometriosis and on fertility and reproduction in adult female rats. Autologous fragments of the endometrium were implantated in the peritoneal cavity in adult female rats. The growth of the endometriotic implants that developed after four weeks was recorded. Treatment started then with β-caryophyllene (10 mg/kg or 30 mg/kg) or vehicle (control) for 21 days and the growth of the endometriotic implants was measured again. In fertility studies, female rats that received β-caryophyllene or vehicle were mated and reproductive functions were observed including number and viability of implants, number of corpora lutea, length of pregnancy and outcome of litter. β-Caryophyllene (10 mg/kg) suppressed the growth of endometriotic implants by 52.5% compared with controls. Also β-caryophyllene produced apoptosis in luminal epithelim of the cyst as well as in endothelial cells of blood vessels. Ultrstructural studies revealed the presence of active mast cells and eosinophils in both control and β-caryophyllene-treated rat cysts. No statistically significant difference was observed in any studied parameter between control and β-caryophyllene-treated groups in fertility study. Therapy with β-caryophyllene may present a promising novel, non-toxic therapeutic option for patients with endometriosis.

Synthesis and biological activity assays of some new N1-(flavon-7-yl)amidrazone derivatives and related congeners.

A series of new N1-(flavon-7-yl)amidrazones incorporating N-piperazines and related congeners were synthesized by reacting the hydrazonoyl chloride derived from 7-aminoflavone and 7-amino-2-methylchromen-4-one with the appropriate piperazine. The chemical structures of the newly prepared compounds were confirmed by elemental analyses, (1)H NMR, (13)C NMR, and ESI-HRMS spectral data. The antitumor activity of these compounds was evaluated on breast cancer (MCF-7 and T47D) and Leukemic (K562) cell lines by a cell viability assay utilizing the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Although with varying degrees, a significant growth inhibitory and cytotoxic effect was observed on all three cancer cell lines. Among the compounds tested compounds, 5a, 15a, and 18b, were the most active against T47D cell line with IC(50) values of 1.42, 1.92, and 2.92 μM, respectively. By using other cancer cell lines and with further characterization of their biological mechanism of action, these compounds could prove to be useful candidates as anticancer drugs.

Gene expression alterations in chronic hypoxic MCF7 breast cancer cell line

Hypoxia plays a significant role in tumor progression and aggressiveness and implicated in resistance to radiotherapy and chemotherapy. This study aims to characterize the changes in gene expression associated with chronic hypoxia in MCF7 breast cancer cell line and identify a possible biomarker for hypoxia in breast cancer. Breast cancer cells (MCF7) were exposed to 8-hour hypoxic episodes (<1% oxygen) three times a week for a total of 38 episodes. Gene expression changes were profiled using RT- PCR array after 19 and 38 episodes of hypoxia and compared to normoxic cells. Chemoresistance of hypoxic cells toward doxorubicin was assessed using MTT cell proliferation assay. Marked gene expression changes were indentified after 19 and 38 episodes of hypoxia. Only few changes were common in both stages with most genes rebounding at the level of 38 episodes. A notable gene (HNF4A) has been up-regulated by 2 folds after 19 hypoxic shots and further up-regulated by 6.43 folds after 38 hypoxic shots. The half maximal inhibitory concentration (IC50) of doxorubicin in MCF7 cells has increased in a trend proportional to the number of hypoxic episodes then totally rebounded after incubation under normoxia for 3 weeks. This study provides evidence that exposing cells to prolonged periods of hypoxia (weeks) results in different expression changes than those induced by short-term hypoxia (less than 72h).

Frequency of genetic polymorphisms of ADAM33 and their association with allergic rhinitis among Jordanians

Allergic rhinitis is a chronic inflammatory disease that is assumed to be due to an interaction between different genetic and/or environmental factors. A disintegrin and metalloprotease domain 33 (ADAM33) has been extensively studied as a susceptibility gene in asthma and has been linked to bronchial hyper-responsiveness. In this study, we investigated the association between ADAM33 single nucleotide polymorphisms and the incidence of allergic rhinitis among the Jordanian population. We conducted a case-control association study on 120 adult individuals diagnosed with allergic rhinitis and 128 normal healthy controls. 8 single-nucleotide polymorphisms in ADAM33 were genotyped using PCR-RFLP method. No significant differences in the allelic frequencies of all SNPs tested between AR patients and the control volunteers were found, although S2 C/G SNP showed a tendency toward significance with P=0.06. On the genotype level significant association were found in the following genotypes: T1 AA, T1 AG, T2 GG, T2 AG, T+1 GG, T+1 AG, V4 CG, S2 CC, S2 CG, Q-1AA. Seven haplotypes were present only within AR patients and eight haplotypes were completely absent from the AR patients. Three haplotypes exhibited significant association with AR P ≤ 0.05, two of them were present only in AR patients. In conclusion, the polymorphisms in the ADAM33 gene are associated with susceptibility to AR in the Jordanian population. Furthermore, the haplotype of the tested SNPs were also associated with the risk of AR.

Screening the Antiangiogenic Activity of Medicinal Plants Grown and Sold in Jordan

Angiogenesis is essential for the growth, invasion, and metastasis of most solid tumors and has become a valuable pharmacological target for cancer prevention and treatment. This study was performed to assess the antiangiogenic activity of 31 medicinal plants grown and sold in Jordan. The antiangiogenic activity was assessed using the rat aortic ring assay. Out of 31 extracts, 15 extracts showed more than 50 % inhibition of the blood vessels outgrowth from the primary tissue explants (p = 0.000). Three of these 15 extracts showed a potential cytotoxic effect on normal fibroblast cells. Four extracts shared antiangiogenic and antiproliferative activity towards MCF7 breast cancer cell lines. Eight extracts demonstrated selective antiangiogenic activity. This is the first report demonstrating the potential antiangiogenic activity of Artemisia judaica, Aloysia citriodora, Salvia egyptiaca, and Calendula arvensis. Some extracts with antiangiogenic activity exhibited selectivity against the endothelial cells proliferation, demonstrating a direct inhibitory activity against the key step in tumor angiogenesis.

Frequency of Certain Single-Nucleotide Polymorphisms and Duplication of CYP2D6 in the Jordanian Population

The CYP2D6 isozymes are responsible for metabolism of 7-10% of clinically available drugs. Genetic polymorphism in CYP2D6 may have an impact on drug efficacy and toxicity. The aim of this study was to determine the allelic frequency of CYP2D6*4, *10, and *17 and CYP2D6*2×N duplication allele in 192 healthy unrelated male and female Jordanian volunteers. Polymerase chain reaction (PCR)-restriction fragment length polymorphism-based methods were used to identify the CYP2D6*4, *10, and *17 genotypes; and allele-specific long PCR was used to determine the CYP2D6*2×N allelic frequency. The CYP2D6*10 allele was the most frequent mutant allele in Jordanians (14.8%) followed by CYP2D6*4 and *17 at 12.8%, and 8.3%, respectively. The duplication allele was found in 13.5% of the studied sample. The CYP2D6*4 G-A heterozygote genotype frequency was 20.3%, and the homozygous mutant genotype was 2.6%. In case of CYP2D6*10 C-T and CYP2D6*17 G-C heterozygote genotypes, the frequencies were 21.4% and 12.5%, respectively, while the homozygous mutant genotype frequencies of T-T and C-C were 4.2% and 2.1%, respectively. In conclusion, the allelic distributions of the CYP2D6 gene among Jordanians are different from other Mediterranean groups, especially the *10 and *17 single-nucleotide polymorphisms, and more importantly the CYP2D6*2×N duplication allele, which seems to follow a gradient reduction in prevalence from Ethiopia to Northern Europe.

Synthesis and Biological Activity of Some 3-(4-(Substituted)- piperazin-1-yl)cinnolines

A new series of 6-substituted-4-methyl-3-(4-arylpiperazin-1-yl)cinnolines 8–10 were synthesized as potential antifungal agents via intramolecular cyclization of the respective 1-(2-arylhydrazono)-1-(4-arylpiperazin-1-yl)propan-2-ones 5–7, mediated by polyphosphoric acid (PPA). The amidrazones themselves were synthesized via direct interaction of the appropriate hydrazonoyl chlorides 4a–d with the corresponding N-substituted piperazine in the presence of triethylamine. The structures of the new prepared compounds were confirmed by elemental analyses, 1H-NMR, 13C-NMR, and ESI-HRMS spectral data. The antitumor, antibacterial, and antifungal activity of the newly synthesized compounds was evaluated.

Alteration of gene expression in MDA-MB-453 breast cancer cell line in response to continuous exposure to Trastuzumab.

Development of resistance against cancer therapeutic agents is a common problem in cancer management. Trastuzumab resistance is one of the challenges in management of HER-2-positive breast cancer patients resulting in breast cancer progression, metastasis, and patient poor outcome. The aim of this study is to determine the alteration in gene expression in response to Trastuzumab resistance after long-term exposure to Trastuzumab. The Trastuzumab-resistant MDA-MB-453 (MDA-MB-453/TR) cell line was developed by exposing cells to 10 μM Trastuzumab continuously for 6 months. Sensitivity toward Trastuzumab was tested using cell viability assays. The acquisition of an epithelial-to mesenchymal transition (EMT) phenotype was also observed in parallel with the development of resistance. Based on the real-time-based PCR array technology, several genes were altered affecting multiple networks. The most up-regulated genes were TGF-β1 and EGF, and IGFBP-3. These genes are known to have a critical role in Trastuzumab resistance in breast cancer cell lines and/or in the acquisition of EMT. They are also recognized for their role in cancer progression and metastasis. These alterations indicate that the development of Trastuzumab resistance is multifactorial and involves a development of a mesenchymal like phenotype.