galloflavin and Neoplasms

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

Most cancer cells switch their metabolism from mitochondrial oxidative phosphorylation to aerobic glycolysis to generate ATP and precursors for the biosynthesis of key macromolecules. The aerobic conversion of pyruvate to lactate, coupled to oxidation of the nicotinamide cofactor, is a primary hallmark of cancer and is catalyzed by lactate dehydrogenase (LDH), a central effector of this pathological reprogrammed metabolism. Hence, inhibition of LDH is a potential new promising therapeutic approach for cancer. In the search for new LDH inhibitors, we carried out a structure-based virtual screening campaign. Here, we report the identification of a novel specific LDH inhibitor, the pyridazine derivative 18 (RS6212), that exhibits potent anticancer activity within the micromolar range in multiple cancer cell lines and synergizes with complex I inhibition in the suppression of tumor growth. Altogether, our data support the conclusion that compound 18 deserves to be further investigated as a starting point for the development of LDH inhibitors and for novel anticancer strategies based on the targeting of key metabolic steps.

Topics: Cell Line; Enzyme Inhibitors; Glycolysis; Humans; L-Lactate Dehydrogenase; Lactic Acid; Neoplasms; Oxidative Phosphorylation

The National Cancer Institute Diversity Set II (1356 compounds) and Diversity Set III (1597 compounds) were screened via in silico methods as potential inhibitors of low molecular weight protein tyrosine phosphatase (LWM-PTP) isoform B (EC 3.1.3.48). Those candidates that demonstrated comparable or better docking scores than that of pyridoxal 5'-phosphate (PLP), one of the most potent known inhibitors of LMW-PTP with a competitive inhibitor dissociation constant (Kis) of 7.6μM (pH 5.0), were analyzed via in vitro kinetic assays against LMW-PTP isoform B. While none of the compounds tested in vitro was significantly better that PLP, five compounds showed comparable inhibition. These five compounds are very diverse in structure and represent new therapeutic leads for inhibition of this isozyme.

Topics: Enzyme Inhibitors; Humans; Molecular Docking Simulation; Neoplasms; Protein Conformation; Protein Isoforms; Protein Tyrosine Phosphatase, Non-Receptor Type 1