Anti-Cancer Agents in Medicinal Chemistry (v.16, #7)

Meet Our Editorial Board Member by A. Conejo-García (791-792).

This review article presents an extensive examination of risk factors for breast cancer, treatment strategies with special attention to photodynamic therapy and natural product based treatments. Breast cancer remains the most commonly occurring cancer in women worldwide and the detection, treatment, and prevention are prominent concerns in public health. Background information on current developments in treatment helps to update the approach towards risk assessment. Breast cancer risk is linked to many factors such as hereditary, reproductive and lifestyle factors. Minimally invasive Photodynamic therapy (PDT) can be used in the management of various cancers; it uses a light sensitive drug (a photosensitizer, PS) and a light of visible wavelength, to destroy targeted cancer cells. State of the art analyses has been carried out to investigate advancement in the search for the cure and control of cancer progression using natural products. Traditional medicinal plants have been used as lead compounds for drug discovery in modern medicine. Both PDT and plant derived drugs induce cell death via different mechanisms including apoptosis, necrosis, autophagy, cell cycle regulation and even the regulation of various cell signalling pathways.

The Mechanism in Gastric Cancer Chemoprevention by Allicin by Runlan Luo, Dengyang Fang, Hongdong Hang, Zeyao Tang (802-809).
Gastric cancer remains high prevalence and fatality rates in China even though its morbidity has been decreased drastically. Allicin, which is from an assistance food-garlic (Allium Sativum L), was found to be effective in gastric cancer treatment. It is a defensive substance with a board biological properties: inhibition of bacteria, fungus, virus, controlled hypertension, diabetes, and chemoprevention of several cancers, etc. Experiments have shown that allicin can be chemopreventive to gastric cancer by inhibiting the growth of cancer cells, arresting cell cycle at G2/M phase, endoplasmic reticulum (ER) stress, and mitochondria-mediated apoptosis, which includes the caspase-dependent/-independent pathways and death receptor pathway. Those mechanisms probably involve in modulating enzymatic activity, restraining DNA formation, scavenging free radicals, and affecting cell proliferation and even tumor growth. Therefore, this review is focus on the mechanism of allicin in gastric cancer.

Blood-Brain Barrier and Breast Cancer Resistance Protein: A Limit to the Therapy of CNS Tumors and Neurodegenerative Diseases by , Anna Lisa Iorio, Martina da Ros, Ornella Fantappiè, Maurizio Lucchesi, Ludovica Facchini, Alessia Stival, Sabrina Becciani, Milena Guidi, Claudio Favre, Maurizio de Martino, Lorenzo Genitori, Iacopo Sardi (810-815).
The treatment of brain tumors and neurodegenerative diseases, represents an ongoing challenge. In Central Nervous System (CNS) the achievement of therapeutic concentration of chemical agents is complicated by the presence of distinct set of efflux proteins, such as ATP-Binding Cassette (ABC) transporters localized on the Blood-Brain Barrier (BBB). The activity of ABC transporters seems to be a common mechanism that underlies the poor response of CNS diseases to therapies.
The molecular characterization of Breast Cancer Resistance Protein (BCRP/ABCG2), as an ABC transporter conferring multidrug resistance (MDR), has stimulated many studies to investigate its activity on the BBB, its involvement in physiology and CNS diseases and its role in limiting the delivery of drugs in CNS.
In this review, we highlight the activity and localization of BCRP on the BBB and the action that this efflux pump has on many conventional drugs or latest generation molecules used for the treatment of CNS tumors and other neurodegenerative diseases.

Nanoliposome is a Promising Carrier of Protein and Peptide Biomolecule for the Treatment of Cancer by Tapan Kumar Giri, Ayan Giri, Tapan Kumar Barman, Subhasis Maity (816-831).
Nano-liposomes are the newly developed delivery systems for cancer therapy that are finding a position particularly suitable as peptide and protein carriers. These are three-layered self-assembled structures with nanoparticulate carrier systems. The overall pharmacological properties of commonly used protein and peptide in cancer therapy can be improved by the incorporation of protein and peptide into the nano-liposome. The surface modifications can be made liposomes to make compatible with targeting ligands has made these nanocarriers for targeted delivery. This review discusses the method of preparation and characterization of liposome based protein peptide delivery for the treatment of cancer. This review also explores latest work intended for targeted treatment of cancer by nano-liposomal protein and peptide delivery system. This type of delivery is targeting protein and peptide to tumor site by avoiding the reticuloendothelial system. Methods of nano-liposome delivery containing protein and peptide are also highlighted.

The ability to accumulate polyphenols with light absorbance allowed early land plants to resist UV irradiation and made survival on land possible. Largely consumed, polyphenols are not synthesized by human being. Present only in plants and some microorganisms, the number of described phenolic compounds (over 8000), is increasing due to the continual evolution of new genes and mutations in response to the adaptation to environmental changes. A wide range of biological studies revealed the antioxidant properties of polyphenols towards human pathologies such as cancer. The health benefits of polyphenols, however, depend on their amount ingested and on their bioavailability. Many factors have great influence on bioavailability of polyphenols such as the climate, agricultural practices, industrial processes and the host microbiota considered to act as a metabolic organ with an important role in human metabolism. The polyphenols anticancer effect relies on their chemical structure, concentration and on the type of cancer. The biological activity of polyphenols has been extensively studied in preclinical assays. Some polyphenols can overcome cancer chemotherapeutic resistance by modulating cancer cells with multiple drug resistance (MDR) overexpression phenotype. In solid tumours and hematological malignances, polyphenols, exert an important role in apoptosis induction, cell growth inhibition, cell cycle arrest, oxidative stress, and in cell migration and differentiation. The combination of flavonoids and chemotherapy seems to be an interesting approach for cancer treatment. In addition, some points related to the polyphenols bioavailability and delivery needs to be elucidated in order to improve their biological effects in vivo.

Synthesis of 4-piperidone Based Curcuminoids with Anti-inflammatory and Anti-Proliferation Potential in Human Cancer Cell Lines by Amit Anthwal, Kundan Singh, M. S.M. Rawat, Amit K. Tyagi, Ashanul Haque, Imran Ali, Diwan S. Rawat (841-851).
A series of 4-piperidone based curcuminoids were synthesized and anticancer potential of these compounds was evaluated against human myeloid leukemia (KBM5) and colon cancer (HCT116) cell lines. Their anti-inflammatory potential was determined through the down-regulation of tumor necrosis factor (TNF)-?-induced nuclear factor (NF)-?B. All compounds, except one, were found to exhibit better cytotoxicity than curcumin at 5 ?M. Furthermore, many compounds have shown good potential to inhibit the TNF-?-induced NF-?B activation. Docking study of the compounds with NF-?B revealed that the binding affinity of the compounds ranged from ?9.0 to ?6.5 kcal/mol with 0-8 H-bonds. It was also observed that amido-ether based mono-carbonyl compounds bound around the same region of NF-?B where polynucleotides are known to bind to exhibit their activity.

New, Substituted Derivatives of Dicarboximides and their Cytotoxic Properties by Bo|ena Kuran, Mariola Napiórkowska, Jerzy Kossakowski, Marcin Cie|lak, Julia Ka|mierczak-Bara|ska, Karolina Królewska, Barbara Nawrot (852-864).
A large group of aminoalkyl and aminoalkanol derivatives of selected dicarboximides were synthesized and characterized by 1HNMR, 13CNMR and ESI MS spectra analysis. The thirty nine new compounds were tested for their cytotoxic properties in human chronic (K562), acute leukemia (HL-60), and cervical cancer cells (HeLa) as well as in normal endothelial cells (HUVEC). The most promising compounds are 4-[2-(dimethylamino)ethyl]-, (diethylamino) ethyl]-, 4-[2-(piperidin-1-yl)ethyl]-, 4-[3-(dimethylamino)propyl]- and 4-[2-hydroxy-3-(propan- 2-ylamino)propyl]- derivatives of 1,7-diethyl-8,9-diphenyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5,10-trione exhibiting high and selective cytotoxicity towards K562 and HL-60 cells (IC50 in the range of 1-10 µM) while being non-toxic towards HUVEC and HeLa cells (IC50> 100 ?M). Moreover, the preliminary studies have showed that 4-[2-(piperidin-1-yl)ethyl]- 1,7-diethyl-8,9-diphenyl-4-azatricyclo [5.2.1.02,6]dec-8-ene-3,5,10-trione induces programmed cell death (apoptosis) in leukemia cells.

Search for novel anticancer lead molecules continues to be a major focus of cancer research due to the limitations of existing drugs such as lack of tumor selectivity, narrow therapeutic index and multidrug resistance of cancer types. Natural molecules often possess better pharmacokinetic traits compared to synthetic molecules as they continually evolve by natural selection process to interact with biological macromolecules. Microbial metabolites constitute nearly half of the pharmaceuticals in market today. Endophytic fungi, owing to its rich chemical diversity, are viewed as attractive sources of novel bioactive compounds. In the present study, we report the purification and characterization of a novel steroidal saponin, cholestanol glucoside (CG) from Saraca asoca endophytic fungus Lasiodiplodia theobromae. The compound was assessed for its cytotoxic potentialities in six human cancer cell lines, A549, PC3, HepG2, U251, MCF7 and OVCAR3. CG exhibited significant cytotoxicities towards A549, PC3 and HepG2 among which A549 cells were most vulnerable to CG treatment. However, CG treatment exhibited negligible cytotoxicity in non malignant human lung fibroblast cell line (WI-38). Induction of cell death by CG treatment in A549 cells was further investigated. CG induced the generation of reactive oxygen species (ROS) and mitochondrial membrane permeability loss followed by apoptotic cell death. Mitochondrial membrane depolarization and apoptotic cell death in CG treated A549 cells were completely blocked in presence of an antioxidant, N-acetyl cysteine (NAC). Hence it could be concluded that CG initiates apoptosis in cancer cells by augmenting the basal oxidative stress and that the generation of intracellular ROS is crucial for the induction of apoptosis.

Synthesis and Cytotoxicity of Two Active Metabolites of Larotaxel by Jianwei Li, Anping Li, Minghua Li, Yufeng Qiao, Hui Zhang (875-880).
Two epimeric metabolites of Larotaxel were synthesized in eight steps from 10-DAB III as a commercial material and their structures were characterized using NMR and MS spectral data. The cytotoxicity of two metabolites was performed on breast cancer cell lines MCF-7, MX-1 and MDA-MB-231. It is remarkable that both of these two desired taxanes showed great potent cytotoxic effect.

Naphthoflavones as Antiproliferative Agents: Design, Synthesis and Biological Evaluation by Dinesh Kumar, Onkar Singh, Kunal Nepali, PMS Bedi, Arem Qayum, Shashank Singh, Subheet K. Jain (881-890).
The present study involves the design and synthesis of naphthoflavones as antiproliferative agents. The strategy presents naphthoflavones as hybrids of naphthyl based chalcones and flavones. A panel of human cancer cell lines were employed for the cytotoxicity studies. DK-13 exhibited significant cytoxicity against MiaPaCa-2 cell lines with IC50 value of 1.93 ?M and 5.63 ?M against MCF-7 cell lines. The compound DK-13 was found to induce apoptosis evidenced through phase contrast microscopy, DAPI staining, and mitochondrial membrane potential loss. The cell phase distribution studies indicated an increase from 11.26 % (control sample) to 55.19 % (sample treated with 20 ?M compound DK-13) in the apoptotic population.

Compounds that can bind and stabilize non-canonical DNA structures are named quadruplex and are of interest in anticancer drug design due to their selective inhibitions of telomerase and consequent effects on cell proliferation. In this study, we report novel Co/Cu [II] complex compounds as G-quadruplex DNA binding ligands. The results from the preliminary assay indicated that the introduction of a positively charged 6-membered tail to the aromatic terminal group of benzimidazole significantly enhanced the binding affinity with the quadruplex and exhibited anti-telomerase activity. These derivatives showed significant selectivities for the telomeric quadruplex over duplex nucleic acids. The stabilization of non-canonical forms estimated with the FRET DNA technology using different sequences, such as F21T, c-kit1 and c-kit2, in cancer cell lines were assessed. Three members of this family showed to be very selective in stabilizing one particular G-quadruplex.

Leuckart Synthesis and Pharmacological Assessment of Novel Acetamide Derivatives by Priyanka Rani, Dilipkumar Pal, Rahul Rama Hegde, Syed Riaz Hashim (898-906).
A new concatenation of N-(1-(4-bromophenyl)ethyl)-2-phenoxyacetamide and N-(1-(4-methoxyphenyl) ethyl)-2-phenoxyacetamide derivatives having 2-phenoxy-N-(1-phenylethyl)acetamide nucleus as common in both the types was synthesized for the sake of achieve titled compounds as potential cytotoxic, anti-inflammatory, analgesic and antipyretic agents. All the novel derivatives have been synthesized through multi-step reaction sequence starting from Leuckart reaction. The structural assignments of the new compounds have been determined by virtue of their IR, 1H NMR, 13C NMR, elemental analysis and mass spectrum analysis. All the synthesized compounds were assessed for cytotoxicity and anti-inflammatory, analgesic and antipyretic effects. Among the series, compounds 3a, 3c, 3g and 3h possess cytotoxic, anti-inflammatory, analgesic and antipyretic activities comparable with standard drugs. The synthesized compounds were found to be active because of the presence of bromo, tert- butyl and nitro groups at position 4 of phenoxy nucleus.

Indole-3-ethylsulfamoylphenylacrylamides with Potent Anti-proliferative and Anti-angiogenic Activities by Samir Mehndiratta, Shiow-Lin Pan, Sunil Kumar, Jing-Ping Liou (907-913).
HDAC inhibition is emerging as a new strategy for cancer therapy. We previously reported that Nhydroxy- 3-{4-[2-(2-methyl-1H-indol-3-yl)-ethylsulfamoyl]-phenyl}-acrylamide (9) demonstrated potent histone deacetylases (HDAC) inhibition and anti-inflammatory effects. This continuous study provides detailed structureactivity relationship (SAR) of novel indol-3-ethylsulfamoylphenylacrylamides as anti-cancer agents. These compounds are endowed with potent HDAC inhibitory activity, almost 2.5 folds to 42 folds better than suberanilohydroxamic acid (SAHA). Compounds 8, 10, 11 and 17 exhibited significant inhibitory effects on various cancer cell lines with GI50 values in the range of 0.02 to 0.35 ?M which are 10-50 folds better than SAHA. In-vivo nude mice model indicated the anti-angiogenic potential of these acrylamides. This study has indicated the potential of 3-{4-[2-(1-Ethyl-2-methyl-1H-indol-3-yl)-ethyl-N-tert-butoxycarbonylsulfamoyl]-phenyl}-N-hydroxy-acrylamide (11, mean GI50 = 0.04 ?M) as a lead molecule for further development as anti-cancer agent.

Synthesis and Biological Evaluation of Scutellaria Flavone Cyclaneaminol Mannich Base Derivatives as Novel CDK1 Inhibitors by Lisha Ha, Yuan Qian, Shixuan Zhang, Xiulan Ju, Shiyou Sun, Hongmin Guo, Qianru Wang, Kangjian Li, Qingyu Fan, Yang Zheng, Hailiang Li (914-924).
Cyclin-dependent kinase 1 (CDK1) is the only necessary CDK in the cell proliferation process and a new target in the research and development of anti-cancer drugs. Natural flavones are selective CDK1 inhibitors which can suppress the proliferation of cancer cells. However, their bioavailability is poor. To solve these problems, 6 Scutellaria flavones were isolated from hydrolyzed products of Scutellaria baicalensis and used as lead compounds, 18 Scutellaria flavones cyclane-aminol Mannich base derivatives were semi-synthesized and their biological activity as novel CDK1 inhibitors was evaluated. Results indicated that the biological activity of 8-Hydroxypiperidinemethyl-baicalein (BA-j) is the highest among these compounds. BA-j is a selective CDK1 inhibitor, and has broad-spectrum anti-proliferative activity in human cancer cells (IC50 12.3?M). BA-j can capture oxygen free radicals (.O2-) and selectively increase intracellular H2O2 level in cancer cells and activated lymphocytes, thus inducing their apoptosis rather than in normal cells. These findings suggest that BA-j selectively induces apoptosis in cancer and activated lymphocyte by controlling intracellular H2O2 level, and can be developed into a novel anti-proliferative agent for the treatment of cancer, AIDS, and some immune diseases.

Determination of the Antiproliferative Activity of New Theobromine Derivatives and Evaluation of Their In Vitro Hepatotoxic Effects by Maya Georgieva, Magdalena Kondeva-Burdina, Javor Mitkov, Virginia Tzankova, Georgi Momekov, Alexander Zlatkov (925-932).
A new series of N-substituted 1-benzyltheobromine-8-thioacetamides were designed and synthesized. Their anti-proliferative activity against human chronic myelocytic leukemia cell K562, human T-cell leukemia cell SKW-3 and human acute myeloid leukemia HL-60 was evaluated. For the tested compounds a concentrationdependent cytotoxic activity was observed, with 7g outlined as the most active compound within the series. The targed compounds were obtained in yields of 56 to 85% and their structures were elucidated by FTIR, 1H NMR, 13C NMR and microanalyses. The compounds purity was proven by elemental analysis and spectral data. In general, the compounds showed low hepatotoxicity on sub-cellular and cellular level. On isolated rat microsomes only 7d showed toxic effect while theobromine, 1-benzyl-theobromine-thioacetic acid (BTTA) and the other new theobromine derivatives were devoid of toxicity. In isolated rat hepatocytes, when compared to theobromine and BTTA, 7f showed lower cytotoxic effects, and 7d exerted higher cytotoxicity. The results indicate 7g as a promising structure for the design of future compounds with low hepatotoxicity and good antiproliferative activity.