Bereket Mochona

Design and evaluation of novel oxadiazole derivatives as potential prostate cancer agents

Various 1,3,4-oxadiazole derivatives have been synthesized and their antiproliferative properties have been studied. The in vitro screening was performed against androgen dependent (LNCaP) and androgen independent (PC-3) prostate cancer cell lines. Most of the compounds showed promising activity. Among them, compounds 2d (IC50=0.22 and 1.3μM) and 2a (IC50=8.34 and 2,5μM) have shown significant activities on PC-3 and LNCaP cell lines respectively. To investigate the mechanism of cell death we performed cell apoptosis staining and cell cycle arrest assay on more sensitive PC-3 cell lines on 2d. The results demonstrated that 2d induced apoptosis and shifted the cells to the sub G0/G1 and S phase. Our study evidently identified the potency of compound 2d as potential anti-prostate cancer agent.

Synthesis and Biological Evaluations of Ring SubstitutedTetrahydroisoquinolines (THIQs) as Anti-Breast Cancer Agents

Breast cancer is a leading cause of mortality among women, resulting in more than half a million deaths worldwide every year. Although chemotherapeutic drugs remain the main stay of cancer treatment, it is observed that toxicity to normal cells poses a limitation to their therapeutic values. Moreover, the patient recovery rate from advanced breast cancer by chemotherapy is still unacceptably low. Tetrahydroisoqinoline derivatives (THIQs) were reported to act as selective subtype estrogen receptor antagonists/agonists and may serve as potential therapeutic agents for breast cancer. In continuation of previous work we systematically synthesized and characterized the tetrahydroisoquinoline (THIQs) analogs. In-vitro antiproliferative activity of new substituted tetrahydroisoquinoline analogs were evaluated against human ER (+) MCF-7 (breast), ER (−) MDA-MB-231 (breast) and Ishikawa (endometrial) cancer cell lines using the CellTiter-Glo luminescent cell viability assay. The most active compounds obtained in this study were 2b, 2i, and 3 g as demonstrated by their activity (IC50=0.2 μg/mL, 0.08 μg/mL; 0.61 μg/mL, 0.09 μg/mL; 0.25 μg/mL, 0.11 μg/mL) against MCF-7 and Ishikawa cell lines respectively, in comparison to Tamoxifen activity (IC50=3.99 μg/mL, 7.87 μg/ml). The newly synthesized molecules were docked in the active sites of the ER-α (PDB: 3ERT), ER-β (PDB: 1QKN) and alpha-beta tubulin taxol complex (1JFF) crystal structures to determine the probable binding modes (bioactive conformations) of the active compounds.

Synthesis, characterization, and electrospinning of novel polyaniline–peptide polymers

Aniline-peptide (FLDQV, FLDQVC, Dansyl-FLDQV, Dansyl-FLDQVC, and FLDQV-AMC) mixtures underwent oxidative chemical and electrochemical polymerization in excess of aniline. The products of the chemical polymerization were low molecular weight polymers containing more than 70% peptide. Electrochemically polymerized species polyaniline-FLDQV (PANI-FLDQV) consisted mainly of polyaniline units containing about 10% peptide. The solubility of the latter in 1,1,1,3,3,3-hexafluoro-2-propanol (HFP) was similar to the camphorsulfonic acid (CSA) doped emeraldine base (PANI-CSA) solubility, however the weight composition of the electrospun fibers produced from the two polymers was significantly different. 2D 1H-13C HSQC analyses were employed to analyze the binding between the aniline and peptide moieties. Binding of peptide to polyaniline is reflected by the appearance of extra cross-peaks which display line broadening between the free polyaniline and the free pentapeptide. Peptides may be chemically bonded to the polymer molecules, but they may also act as doping agents to the nitrogen atoms via hydrogen bonding.

Abstract C14: The Florida ReTOOL Program: Creating a training bridge for the next generation of biomedical scientists

Background and Objective: There is a need to develop a cadre of racially and ethnically diverse, well-trained scientists to: (1) increase the capacity for scientific research among underserved populations; (2) address cultural appropriateness of the conceptualization, design and implementation of research ideas; (3) effectively and respectfully deliver health care interventions for diverse populations; and (4) eliminate health disparities. To achieve our long-term goal of increasing the pool of minority cancer researchers, the objective of the Florida Cancer Research Training Opportunities for Outstanding Leaders (ReTOOL) program is to develop, promote and sustain an independent, competitive cancer research training program that creates opportunities and promotes careers in cancer research for underrepresented minority (URM) students. The ReTOOL program trains URM students from University of Florida (UF), Florida AM (2) dedicated mentor pool of nationally recognized scientists who are committed to diversity and have expertise in the area of basic, behavioral or clinical sciences; (3) committed faculty advisors at the home (minority) institutions who provide preparatory training and continuous mentoring for trainees; (4) a culturally responsive staff at the cancer center to assist trainees effectively navigate the resources at the cancer center and provide support outside academic/professional development; (5) an effective recruitment process that includes rigorous screening process and orientation; (6) clear requirements and expectations for the training program; (7) cradle to grave system to support trainees; and (8) trainee tracking and evaluation. The ReTOOL program focuses on successfully bridging URM students to graduate or medical school and supporting the trainees throughout their career. The program includes: (i) Basic ReTOOL 12-week summer training, funded by the US Department of Defense, for URM students without research experience; (ii) Academy I ReTOOL 12-week summer training, funded by the National Cancer Institute and UFHCC, for continuous/subsequent training of Basic ReTOOL alumni; (iii) Academy II ReTOOL 1-year post-baccalaureate training (if needed), funded by the UFHCC, to bridge ReTOOL alumni to graduate/medical school; and (iv) triad continuous mentoring by ReTOOL program director, FAMU/BCU minority institution faculty advisor and UF faculty mentor. Results: 19 URM students successfully completed the program between 2012 and 2015. The scholarly achievements of the program include 20 completed projects by URM students, 12 published scientific abstracts presented at national/international conferences, 3 publications, 3 publications in progress, 3 grant awards based on the ReTOOL program, and 12 student recognitions/awards. Six students have been admitted to graduate/medical schools, including UF, FAMU, Duke University, Indiana University and Howard University. 2 students have just been admitted to the Academy II ReTOOL 1-year post-baccalaureate training at UF. The ReTOOL program has also led to an increase in cancer health disparities research at UF, especially among the ReTOOL mentors. According to a ReTOOL mentee: “The growth that I have made is without a doubt beneficial to me progressing towards the next chapter in my life.” A ReTOOL mentor stated in his evaluation, “Rewarding opportunity to teach and mentor minority students in the field of prostate cancer.” Conclusion: Developing and sustaining the interests of URM students in biomedical science requires a comprehensive and sustainable approach, as seen in the ReTOOL program. The success of the ReTOOL program has led to a training model for diversity in graduate programs at UF and currently being adopted by multiple departments at UF. Citation Format: Folakemi T. Odedina, Merry Jennifer Markham, Renee Reams, Bereket Mochona, Dixon Alma, Nguyen Jennifer, Gilbert Lauren. The Florida ReTOOL Program: Creating a training bridge for the next generation of biomedical scientists. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C14.

Abstract 2229: Synthesis of heterocyclic compounds as anticancer agents.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Cancer is a very complex disease, linked with different initiating causes, cofactors and promoters, and several types of cellular damages. There is a strong correlation between chronic inflammatory conditions in a particular organ and cancer specific to that organ. The longer the inflammation persists, the higher the risk of associated carcinogenesis. Drug discovery process has changed dramatically over the past decade as there is an increasing demand to obtain more drug candidates and decrease attrition during drug development. Chromone scaffold [(4H)-1-benzopyran-4-one] has been recognized as a pharmacophore of a large number of bioactive molecules of either natural or synthetic origin. Until now, numerous biological effects such as anti-inflammatory, antitumoral, and antimicrobial activities especially in popular medicine, have been attributed to this benzo-γ-pyrone nucleus. Compounds of this type also possess inhibition properties towards different enzymes such as oxidoreductases, kinases, tyrosinases, lipoxygenases and cyclooxygenases. Chemotherapeutic agents like tetrahydropyridine (THP) analogs exhibit diverse biological activities like analgesic and anti-inflammatory effects. Our earlier research results indicated that some of the THP derivatives showed COX-2 inhibition and anti-inflammatory activities on rat paw edema assay studies. Incorporation of THP moiety might enhance biological activity of the chromone derivatives. Herein, we report the synthesis of substituted N-(5,6-dihydropyridin-1-(2H)-yl)-4-oxo-4H-chromene-2-carboxamide as anticancer and anti-inflammatory agents. The starting material 4-oxo-4H-chromene-2-carbonyl chloride was obtained by the reaction of 4-oxo-4H-chromene-2-carboxylic acid, dissolved in 1,2-dichloroethane and SOCl2 containing few drops of DMF under reflux for 4h. The crude acid chloride obtained by removing the excess of SOCl2 and solvent under vaccum, was used immediately for next step. Reaction of the acid chloride with substituted N-amino pyridinium salt in anhydrous tetrahydrofuran gave stable ylides. This was followed by reduction with sodim borohydride in absolute ethanol, which furnished the target compound. These compounds were evaluated for their cytotoxic effects on MCF-7 ER positive breast cancer cells, MDA-MB ER receptor negative breast cancer cells, and Ishikawa cell line using the CellTiter-Glo (CTG) luminescent cell viability assay. N-(4-tert-butyl-5,6-dihydropyridin-1(2H)-yl)-6-chloro-7-methyl-4-oxo-4H-chromene-2-carboxamide showed the cytotoxicity with an IC50 values of 73.28 μM on MDA-MB-231 cell lines. This research was supported by the National Center for Research Resources and the National Institute of Minority Health and Health Disparities of the National Institutes of Health through Grant Number 8 G12MD007582-28. Citation Format: Kinfe Ken Redda, Madhavi Gangapuram, Mohammad A. Ghaffari, Suresh Eyunni, Nelly Mateeva, Bereket Mochona. Synthesis of heterocyclic compounds as anticancer agents. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2229. doi:10.1158/1538-7445.AM2013-2229

Abstract 3263: Synthesis of substituted N-(4-(6-methyl-1H-benzo[d]imidazol-2-yl)-5,6-dihydropyridin-1(2H)-yl) benzamide/benzenesulfonamide as anticancer agents

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL There is a strong association between chronic inflammatory conditions in a particular organ and the incidence of cancer specific to that organ. The longer the inflammation persists, the higher is the risk of associated carcinogenesis. Our interest is to synthesis new, potent and safer anticancer agents. The functionalized tetrahydropyridine (THP) ring systems are widely found in biologically active natural products and pharmaceuticals. The pharmacological activities of the THP derivatives depended greatly on the position and nature of the substitutions on the THP ring structure. 2-Substituted benzimidazole derivatives have been found to possess anti-inflammatory, antihistaminic, antimicrobial, anticancer, and cycloxygenase inhibiting activities. It is believed that synthesizing new compounds that contain both the pharmacophores of THP and benzimidazole could have the potential of becoming effective anticancer agents. 6-Methyl-2-(pyridin-4-yl)-1H-benzo[d]imidazole was obtained by the reaction of isonicotinc acid, 4-methyl benzene-1,2-diamine and polyphosphoric acid, which were stirred in an oil bath at 180oC for 2h. Mesitylene sulfonyl chloride was added with stirring to a solution of ethylacetohydroxymate and triethylamine in dimethylformamide at 0o C. Hydrolysis of this compound with the mixture of p-dioxane and 70% perchloric acid for 45 min gave a white solid of MSH. The MSH reacted with 6-methyl-2-(pyridin-4-yl)-1H-benzo[d]imidazole to give 1-amino-4-(6-methyl-1H-benzo[d]- imidazol-2-yl) pyridinium mesitylenesulfonate, which further reacted with different substituted benzoyl chlorides/benzenesulfonyl chlorides in 10% NaOH solution to gave stable benzoyl/benzenesulfonyl imino ylides. These ylides were reduced using sodium borohydride in absolute ethanol and gave the target compounds, substituted N-(4-(6-methyl-1H-benzo[d]imidazol-2-yl)-5,6-dihydropyridin-1(2H)-yl)benzamide/benzenesulfonamides. The cytotoxic effects of these substituted THP derivatives were determined using the MCF-7 estrogen receptor positive breast cancer cells, MDA-MB-231 estrogen receptor negative breast cancer cells, and Ishikawa cells, using the CellTiter-Glo (CTG) luminescent cell viability assay. Two target molecules exhibited strong cytotoxicity activities with significant IC50 values on MCF-7, Ishikawa and MDA-MB-231 cell lines. This research was supported by the NIH/RCMI Grant G12RR03020 and Pharmaceutical Research Center NIH/NCRR Grant 1 C06 RR12512-01. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3263. doi:10.1158/1538-7445.AM2011-3263

Abstract 1369: Synthesis of substituted N-[(3-(1H-pyrrol-1yl)methyl]-5,6-dihydropyridin-1(2H)-yl) benzamide/benzene sulfonamide as anticancer agents

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Cancer has proven to be one of the most intractable human diseases, and as yet no anticancer agents that are highly effective and safe are available. Therefore, synthesis of novel, potent, selective and less toxic anticancer agents remains the most pressing goal of many investigators. Tetrahydropyridine (THP) ring moieties have attracted synthetic interests for being essential structures in many agrochemicals as well as medicinal agents. The anti-inflammatory and anticancer activities of compounds consisting of reduced pyridine ring systems were investigated in our laboratory. The pharmacological activities of the (THP) derivatives depended on the nature of the substituents on the THP ring moiety. In the current investigation, we synthesized many analogs maintaining the N-(3-[(1-H-pyrrol-1-yl)methyl]-5,6-dihydropyridin-1(2H)-yl) benzamide/benzene sulfonamides, at which the phenyl ring was substituted with groups having different electronic, steric and lipophilic properties. Mesitylene sulfonyl chloride was added with stirring to a solution of ethylacetohydroxymate and triethylamine in dimethylformamide at 0o C. Hydrolysis of this compound with the mixture of p-dioxane-70% perchloric acid and allowing them to react for 45 min gave a white solid of O-mesitylene sulfonyl hydroxylamine (MSH). MSH was used to prepare the N-amino salt since it served as an aminating agent. 3-[(1H-pyrrol-1-yl)methyl]pyridine was reacted with MSH in dichloromethane to produce 3-[(1H-pyrrol-1-yl)methyl]-1-aminopyridinium mesitylenesulfonate, the N-amino salt. Reaction of the amino salt with substituted benzoyl chloride/benzenesulfonyl chloride in anhydrous tetrahydrofuran containing triethylamine gave stable benzoyl/benzene sulfonyl imino ylides. This was followed by reduction with sodium borohydride in absolute ethanol, which furnished the target compounds substituted N-(3-[(1H-pyrrol-1-yl)methyl]-5,6-dihydropyridin-1(2H)-yl) benzamide/benzene sulfonamides. These compounds were evaluated for their cytotoxic effects on MCF-7 estrogen receptor positive breast cancer cells, MDA-MB-231 estrogen receptor negative breast cancer cell line, and Ishikawa cells, using the CellTiter-Glo (CTG) luminescent cell viability assay. N-(3-[(1H-pyrrol-1-yl)methyl]-5,6-dihydropyridin-1(2H)-yl)-4-methoxybenzene- sulfonamide showed the most potent cytotoxicity with an IC50 values of 47, 28, and 44 µM on MCF-7, Ishikawa and MDA-MB-231 cell lines, respectively. This research was supported by NIH/ RCMI Grant # G12 RR 03020 and Pharmaceutical Research Center NIH/NCRR Grant 1 C06 RR12512-01. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1369. doi:10.1158/1538-7445.AM2011-1369