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Rana Mohamad Riad Bazzi

Associate professor
Life & Earth Sciences department - Section I - Hadath
Speciality: Biology
Specific Speciality: Ph.D Genetics

Teaching 4 Taught Courses
(2014-2015) BioA 456 - Pharmacogenomic

M1 Applied Animal Science

(2014-2015) GNSA 501 - Functional Genomics

M2 Genomics and Health

(2014-2015) Biol 113 - Genetics, human anatomiy and plant reproduction

BS Earth and life sciences

(2014-2015) Biol 380 - Molecular Genetics

BS Biochemistry

Education
PhD

Nottingham University (UK)
Genetics

DEA

Université Claude Bernard Lyon 1, France
Biochemistry

Maitrise

Lebanese University, Lebanon (Hadath)
Biochimie

Baccalaureat

Al Batoul High School
Life Sciences

Publications 4 publications
Richard J. Wall, David R. Bell, Rana Bazzi, Alwyn Fernandes, Martin Rose, et al., Fused mesoionic heterocyclic compounds are a new class of aryl hydrocarbon receptor (AhR) agonist of exceptional potency Toxicology 2012

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most potent ligands of the aryl hydrocarbon receptor (AhR). Here, we show that a novel fused mesoionic heterocyclic compound (AZ1) is ∼5-fold more potent than TCDD in both rat and human cell lines at inducing cytochrome P4501A1 RNA. In rat H4IIE cells, AZ1 gave an EC(50)=5.05 pM (95% CI=2.81-9.09 pM) whereas TCDD had an EC(50)=25.5 pM (95% CI=18.2-36.0 pM). AZ1 was also more potent than TCDD (5-10-fold) at inducing the AhR-related CYP1A2 and CYP1B1 genes, showing that AZ1 is more potent at inducing multiple genes. In human MCF-7 cells AZ1 gave an EC(50)=65.4 pM (95% CI=45.6-93.7 pM) and TCDD an EC(50)=241 pM (95% CI=161-362 pM), showing that AZ1 was more potent than TCDD at inducing CYP1A1 RNA in multiple species. Finally, the compound bound to rat cytosolic AhR with 6-fold higher affinity than TCDD, showing that the highly potent agonism of this substance is mediated via a high affinity for the receptor. This data shows that this novel compound, which shares structural similarities with various naphthoflavones, is a potent ligand of the AhR.

Bazzi R, Bradshaw TD, Rowlands JC, Stevens MF, Bell DR. 2-(4-Amino-3-methylphenyl)-5-fluorobenzothiazole is a ligand and shows species-specific partial agonism of the aryl hydrocarbon receptor Toxicol Appl Pharmacol 2009

2-(4-Amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) and related compounds are a series of anti-cancer candidate pharmaceuticals, that have been shown to activate the AhR. We show that these compounds are high-affinity ligands for the rat AhR, but a quantitative assay for their ability to induce CYP1A1 RNA in H4IIEC3 cells, a measure of activation of the AhR, showed a poor relationship between affinity for the AhR and ability to induce CYP1A1 RNA. 5F 203, an agonist with low potency, was able to antagonise the induction of CYP1A1 RNA by TCDD, while IH 445, a potent agonist, did not antagonise the induction of CYP1A1 RNA by TCDD, and Schild analysis confirmed 5F 203 to be a potent antagonist of the induction of CYP1A1 RNA by TCDD in H4IIEC3 cells. In contrast, several benzothiazoles show potent induction of CYP1A1 RNA in human MCF-7 cells, and 5F 203 is unable to detectably antagonise the induction of CYP1A1 RNA in MCF-7 cells, showing a species difference in antagonism. Evaluation of the anti-proliferative activity of benzothiazoles showed that the ability to agonise the AhR correlated with growth inhibition both in H4IIEC3 cells for a variety of benzothiazoles, and between H4IIEC3 and MCF-7 cells for 5F 203, suggesting an important role of agonism of the AhR in the anti-proliferative activity of benzothiazoles.

Aiello S, Wells G, Stone EL, Kadri H, Bazzi R, Bell DR, Stevens MF, Matthews CS, Bradshaw TD, Westwell AD Synthesis and biological properties of benzothiazole, benzoxazole, and chromen-4-one analogues of the potent antitumor agent 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole (PMX 610, NSC 721648). J Med Chem 2008

New fluorinated 2-aryl-benzothiazoles, -benzoxazoles, and -chromen-4-ones have been synthesized and their activity against MCF-7 and MDA 468 breast cancer cell lines compared with the potent antitumor benzothiazole 5. Analogues such as 9a, b and 12a, d yielded submicromolar GI50 values in both cell lines; however, none of the new compounds approached 5 in terms of antitumor potency. For 5, binding to the aryl hydrocarbon receptor appeared to be necessary but not sufficient for growth inhibition

Kristian W. Fried, Rana Bazzi, Walkiria Levy Lopez, Claudia Corsten, Karl-Werner Schramm, David R. Bell, Karl K. Rozman Relationship between aryl hydrocarbon receptor-affinity and the induction of EROD activity by 2,3,7,8-tetrachlorinated phenothiazine and derivatives Toxicology and Applied Pharmacology 2007

Reported herein are semi-empirical calculations of the molecular geometry of TCDD, TCPT, TCPT-sulfoxide (TCPT-O), TCPT-sulfone (TCPT-O2), N-methyl-TCPT (Me-TCPT), N-methyl-TCPT-sulfoxide (Me-TCPT-O), and N-methyl-TCPT-sulfone (Me-TCPT-O2), the characterization of their AhR binding affinity in rat hepatic cytosol, and their ability to induce EROD activity in a rat hepatoma cell line in vitro. Semi-empirical calculations yielded detailed information about the stereochemistry and the preferred conformation of each of these compounds. These results in combination with observations reported in this paper were used to determine structure–activity relationships. In vitro displacement of 3H-TCDD was measured by increasing concentrations of the respective ligands. This assay revealed a strong binding affinity of TCPT to the AhR with a Ki value of 1.08 nM. TCDD had a Ki value of 0.54 nM. The affinity of TCPT derivatives for the AhR decreased with increasing degree of oxidation. Moreover, N-methylation further lowered the affinity, so that the N-methyl sulfone derivative of TCPT displayed the highest Ki at ∼ 1200 nM (= 460.4 ng/ml). A corresponding trend was observed regarding the potency of TCPT and derivatives to induce EROD activity in vitro. However, the potencies were considerably lower than that of TCDD. Enzyme induction was measured in a rat hepatoma cell line H4IIEC/T3 by quantification of ethoxyresorufin-O-deethylase (EROD) activity. Induction was measured at 12, 24, 48 and 72 h to determine time dependence. Sulfoxidated and N-methylated phenothiazines displayed a lower potency than their respective parent compounds. TCPT and all derivatives induced enzyme activity at an efficacy similar to TCDD at all time points measured. The reported findings clearly separate the induction of EROD activity by TCPT and derivatives from their binding affinities to the AhR. In contrast, a direct correlation between the two is generally assumed in drug development, leading to – in our view – unwarranted termination of drug candidates. Therefore, a lack of such a correlation for TCPT and derivatives in fact supports their further development as possible drug leads.

Languages
Arabic

Native or bilingual proficiency

English

Full professional proficiency

French

Full professional proficiency