myricetin and Neoplasms

Protein kinases have been important targets for antitumor targets due to their key roles in regulating multiple cell signaling pathways. Numerous compounds containing flavonoid scaffold as an indispensable anchor have been found to be potent inhibitors of protein kinases. Some of these flavonoids have been in clinical research as protein kinases inhibitors. Thus, the present review mainly focuses on the structural requirement for anticancer potential of flavone derivatives targeting several key serine/threonine protein kinases. This information may provide an opportunity to scientists of medicinal chemistry to design multi-functional flavone derivatives for the treatment of cancer.

Topics: Animals; Antineoplastic Agents; Flavones; Humans; Neoplasms; Protein Binding; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases

Inhibitors of the ubiquitin-proteasome system (UPS) have been the object of research interests for many years because of their potential as anti-cancer agents. Research in this field is aimed at improving the specificity and safety of known proteasome inhibitors. Unfortunately, in vitro conditions do not reflect the processes taking place in the human body. Recent reports indicate that the components of human plasma affect the course of many signaling pathways, proteasome activity and the effectiveness of synthetic cytostatic drugs. Therefore, it is believed that the key issue is to determine the effects of components of the human diet, including effects of chemically active polyphenols on the ubiquitin-proteasome system activity in both physiological and pathological (cancerous) states. The following article summarizes the current knowledge on the direct and indirect synergistic and antagonistic effects between polyphenolic compounds present in the human diet and the efficiency of protein degradation via the UPS.

Topics: Animals; Diet; Humans; Neoplasms; Phenols; Polyphenols; Proteasome Endopeptidase Complex; Ubiquitin

The emergence of drug resistance, coupled with the issue of low tumor selectivity and toxicity is a major pitfall in cancer chemotherapy. It has necessitated the urgent need for the discovery of less toxic and more potent new anti-cancer pharmaceuticals, which target the interactive mechanisms involved in division and metastasis of cancer cells. Human DNA ligase I (hligI) plays an important role in DNA replication by linking Okazaki fragments on the lagging strand of DNA, and also participates in DNA damage repair processes. Dysregulation of the functioning of such ligases can severely impact DNA replication and repair pathways events that are generally targeted in cancer treatment. Although, several human DNA ligase inhibitors have been reported in the literature but unfortunately not a single inhibitor is currently being used in cancer chemotherapy. Results of pre-clinical studies also support the fact that human DNA ligases are an attractive target for the development of new anticancer agents which work by the selective inhibition of rapidly proliferating cancer cells. In this manuscript, we discuss, in brief, the structure, synthesis, structure-activity-relationship (SAR) and anticancer activity of recently reported hLigI inhibitors.

Topics: Antineoplastic Agents; Cell Proliferation; DNA Ligase ATP; Enzyme Inhibitors; Humans; Neoplasms; Structure-Activity Relationship

Human apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein which is essential in the base excision repair (BER) pathway of DNA lesions caused by oxidation and alkylation. This protein hydrolyzes DNA adjacent to the 5'-end of an apurinic/apyrimidinic (AP) site to produce a nick with a 3'-hydroxyl group and a 5'-deoxyribose phosphate moiety or activates the DNA-binding activity of certain transcription factors through its redox function. Studies have indicated a role for APE1/Ref-1 in the pathogenesis of cancer and in resistance to DNA-interactive drugs. Thus, this protein has potential as a target in cancer treatment. As a result, major efforts have been directed to identify small molecule inhibitors against APE1/Ref-1 activities. These agents have the potential to become anticancer drugs. The aim of this review is to present recent progress in studies of all published small molecule APE1/Ref-1 inhibitors. The structures and activities of APE1/Ref-1 inhibitors, that target both DNA repair and redox activities, are presented and discussed. To date, there is an urgent need for further development of the design and synthesis of APE1/Ref-1 inhibitors due to high importance of this protein target.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Enzyme Inhibitors; Humans; Neoplasms; Oxidation-Reduction

The thioredoxin system plays an important role in cancer cells. Inhibiting thioredoxin reductase (TrxR) has emerged as an effective strategy to selectively target cancer cells. Withangulatin A (

Topics: Antineoplastic Agents; Enzyme Inhibitors; Humans; Inhibitory Concentration 50; Neoplasms; Pregnenes; Structure-Activity Relationship; Thioredoxin-Disulfide Reductase

The protective effects of kaempferol against reactive oxygen species (ROS)-induced hemolysis and its antiproliferative activity on human cancer cells were evaluated in this study. Kaempferol exhibited strong cellular antioxidant ability (CAA) with a CAA value of 59.80 ± 0.379 μM of quercetin (QE)/100 μM (EC50 = 7.74 ± 0.049 μM). Pretreatment with kaempferol significantly attenuated the ROS-induced hemolysis of human erythrocyte (87.4% hemolysis suppressed at 100 μg/mL) and reduced the accumulation of toxic lipid peroxidation product malondialdehyde (MDA). The anti-hemolytic activity of kaempferol was mainly through scavenging excessive ROS and preserving the intrinsic antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) activities in normal levels. Additionally, kaempferol showed significant antiproliferative activity on a panel of human cancer cell lines including human breast carcinoma (MCF-7) cells, human stomach carcinoma (SGC-7901) cells, human cervical carcinoma (Hela) cells and human lung carcinoma (A549) cells. Kaemperol induced apoptosis of MCF-7 cells accompanied with nuclear condensation and mitochondria dysfunction.

Topics: Antioxidants; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Erythrocytes; HeLa Cells; Hemolysis; Humans; Kaempferols; MCF-7 Cells; Molecular Structure; Neoplasms; Protective Agents; Reactive Oxygen Species; Structure-Activity Relationship

The apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional enzyme involved in DNA repair and activation of transcription factors through its redox function. The evolutionarily conserved C- and N-termini are involved in these functions independently. It is also reported that the activity of APE1/Ref-1 abruptly increases several-fold in various human cancers. The control over the outcomes of these two functions is emerging as a new strategy to combine enhanced DNA damage and chemotherapy in order to tackle the major hurdle of increased cancer cell growth and proliferation. Studies have targeted these two domains individually for the design and development of inhibitors for APE1/Ref-1. Here, we have made, for the first time, an attempt at a comparative analysis of APE1/Ref-1 inhibitors that target both DNA repair and redox activities simultaneously. We further discuss their scope and limitations with respect to the development of potential anticancer agents.

Topics: Antineoplastic Agents; DNA Repair; DNA-(Apurinic or Apyrimidinic Site) Lyase; Drug Design; Humans; Neoplasms; Oxidation-Reduction

Topics: Animals; Antineoplastic Agents; Antitubercular Agents; Diabetes Mellitus; Humans; Hypoglycemic Agents; Insulin Resistance; Isoenzymes; Models, Molecular; Molecular Targeted Therapy; Mycobacterium tuberculosis; Neoplasms; Protein Conformation; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins

The identification of self-renewing and multipotent neural stem cells (NSCs) in the mammalian brain holds promise for the treatment of neurological diseases and has yielded new insight into brain cancer. However, the complete repertoire of signaling pathways that governs the proliferation and self-renewal of NSCs, which we refer to as the 'ground state', remains largely uncharacterized. Although the candidate gene approach has uncovered vital pathways in NSC biology, so far only a few highly studied pathways have been investigated. Based on the intimate relationship between NSC self-renewal and neurosphere proliferation, we undertook a chemical genetic screen for inhibitors of neurosphere proliferation in order to probe the operational circuitry of the NSC. The screen recovered small molecules known to affect neurotransmission pathways previously thought to operate primarily in the mature central nervous system; these compounds also had potent inhibitory effects on cultures enriched for brain cancer stem cells. These results suggest that clinically approved neuromodulators may remodel the mature central nervous system and find application in the treatment of brain cancer.

Topics: Animals; Cell Survival; Cells, Cultured; Mice; Molecular Structure; Neoplasms; Neurons; Pharmaceutical Preparations; Sensitivity and Specificity; Stem Cells