Identification of GAPDH as a protein target of the saframycin antiproliferative agents

Xing, Chengguo; LaPorte, Jacob R.; Barbay, J. Kent; Myers, Andrew G.

doi:10.1073/pnas.0307476101

Cited by 72 publications

(42 citation statements)

References 27 publications

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“…Nevertheless, such activity alone would be unlikely to account for the antimigratory activity of DX-52-1 or HUK-921 because other DNA-alkylating agents such as saframycin C (18), another reactive tetrahydroisoquinoline, and mitomycin C (8) do not inhibit cell migration during wound closure by MDCK cell sheets. Interestingly, covalent DNA-saframycin C adducts bind glyceraldehyde-3-phosphate dehydrogenase, and this appears to be involved in the mechanism of the antiproliferative activity of saframycin C (55). The data presented here extend the notion that reactive tetrahydroisoquinolines possess important protein targets and that their cellular activities may not be confined to or even principally result from any targeting of DNA.…”

Section: Discussionsupporting

confidence: 63%

Analogs of Tetrahydroisoquinoline Natural Products That Inhibit Cell Migration and Target Galectin-3 Outside of Its Carbohydrate-binding Site

Kahsai

Cui

Kaniskan

et al. 2008

Journal of Biological Chemistry

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Cell migration is central to a number of normal and disease processes. Small organic molecules that inhibit cell migration have potential as both research probes and therapeutic agents. We have identified two tetrahydroisoquinoline natural product analogs with antimigratory activities on Madin-Darby canine kidney epithelial cells: a semisynthetic derivative of quinocarmycin (also known as quinocarcin), DX-52-1, and a more complex synthetic molecule, HUK-921, related to the naphthyridinomycin family. It has been assumed that the cellular effects of reactive tetrahydroisoquinolines result from the alkylation of DNA. We have reported previously that the primary target of DX-52-1 relevant to cell migration appears to be the membranecytoskeleton linker protein radixin. Here we extend the analysis of the protein targets of DX-52-1, reporting that the multifunctional carbohydrate-binding protein galectin-3 is a secondary target of DX-52-1 that may also be relevant to the antimigratory effects of both DX-52-1 and HUK-921. All known inhibitors of galectin-3 target its ␤-galactoside-binding site in the carbohydrate recognition domain. However, we found that DX-52-1 and HUK-921 bind galectin-3 outside of its ␤-galactoside-binding site. Intriguingly HUK-921, although a less potent inhibitor of cell migration than DX-52-1, had far greater selectivity for galectin-3 over radixin, exhibiting little binding to radixin, both in vitro and in cells. Overexpression of galectin-3 in cells led to a dramatic increase in cell adhesion on different extracellular matrix substrata as well as changes in cell-cell adhesion and cell motility. Galectin-3-overexpressing cells had greatly reduced sensitivity to DX-52-1 and HUK-921, and these compounds caused a change in localization of the overexpressed galectin-3 and reversion of the cells to a more normal morphology. The converse manipulation, RNA interference-based silencing of galectin-3 expression, resulted in reduced cell-matrix adhesion and cell migration. In aggregate, the data suggest that DX-52-1 and HUK-921 inhibit a carbohydrate binding-independent function of galectin-3 that is involved in cell migration.

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Section: Discussionsupporting

confidence: 63%

Analogs of Tetrahydroisoquinoline Natural Products That Inhibit Cell Migration and Target Galectin-3 Outside of Its Carbohydrate-binding Site

Kahsai

Cui

Kaniskan

et al. 2008

Journal of Biological Chemistry

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“…This intermediate has been implicated in the formation of covalent bonds with DNA. [23][24][25][26] The complex structure of the ecteinascidins is usually deconvoluted into three parts. Both subunits A and B represent the two tetrahydroisoquinoline rings forming the characteristic pentacycles resembling the saframycin-renieramycin framework.…”

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confidence: 99%

Chemistry of Ecteinascidins. Part 4: Preparation of 2′-<i>N</i>-Acyl Ecteinascidin 770 Derivatives with Improved Cytotoxicity Profiles

Tsujimoto

Lowtangkitcharoen

Mori

et al. 2013

CHEMICAL & PHARMACEUTICAL BULLETIN

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We report herein eleven 2′-N-acyl derivatives that were prepared from ecteinascidin 770 (Et 770: 1b) via 18,6′-O-bisallyl protected compound (4) in excellent yields. 2′-N-Acyl derivatives (6a-k) generally showed higher cytotoxicity than 1b. Among them, 3-quinolineacyl derivative (6g) and 4-fluorocinnamoyl derivative (6h) exhibited approximately 50-and 70-fold higher cytotoxicity to the HCT116 human colon carcinoma cell line, respectively, than 1b. Both compounds are potent inhibitors of the in vitro growth of several tumor cells and are therefore promising leads for further optimization. We also report the transformation of 1b into Et 788 (3), which is the first example of an ecteinascidin derivative having a primary amide at C-21 position.Key words ecteinascidin; marine natural product; structure-activity relationship study; transformation; cytotoxicity Members of the tetrahydroisoquinoline family of natural products have persistently attracted considerable interest for more than 30 years due to their novel structures and meager availability in nature, as well as their potent antitumor activity 1,2) ( Fig. 1). Of particular significance is ecteinascidin 743 (Et 743, 1a), which has received plentiful attention for its strong in vivo antitumor activity.3,4) It is marketed in over fifty countries for the treatment of soft-tissue sarcoma, and phase II/III clinical trials for the treatment of other cancers are ongoing. 5,6) Unfortunately, compared with the many structureactivity relationship (SAR) studies of related natural products, such as saframycins and renieramycins, 7-15) SAR studies of ecteinascidins have been limited because of their meager amounts and the low chemical diversity of their biosynthetically produced derivatives. 16)As part of our search for new metabolites via the isolation and characterization of biologically active compounds from Thai marine invertebrates, we isolated ecteinascidin 770 (Et 770: 1b) in gram scale from the Thai tunicate Ecteinascidia thurstoni by pretreatment with potassium cyanide in buffer solution. We also elucidated the structures of 1b and its sulfoxide, Et 786 (2).17) The availability of 1b enabled us to prepare several ecteinascidin derivatives possessing improved cytotoxicity profiles. We previously reported the preparation of 6′-O-acyl derivatives of 1b and established their cytotoxicity in several human tumor cell lines. 18) We found that the nitrogen-containing heterocyclic ester derivatives showed similar in vitro cytotoxicity to 1b, whereas the other derivatives were less cytotoxic than 1b. We also reported a three-step transformation of 1b into 2′-N-acyl derivative 6 via 18,6′-O-bisallyl protected derivative 4 and determined the in vitro cytotoxicity of 6 by measuring IC 50 values in HCT 116 human colon carcinoma, QG56 human lung carcinoma, and DU145 human prostate carcinoma cell lines. 19) In this paper, we report the preparation of eleven additional 2′-N-acyl derivatives from 1b via 4, most of which exhibited higher cytotoxicity than parent 1b and the previousl...

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“…However, a more recent study documented that nitric oxide can also induce nuclear localization of GAPDH where it is acetylated by the acetyltransferase p300/CBP via direct protein interaction, which in turn causes stimulation of the catalytic activity of p300/CBP, resulting in the activation of downstream targets such as p53 (11). Other studies have shown that GAPDH is associated with DNA-containing genotoxic lesions such as thioguanylated DNA generated by the chemotherapeutic agent mercaptopurine used for treating acute lymphoblastic leukemia (12,13). Thus, it seems that GAPDH response to oxidative stress might be linked to a role in maintaining the integrity of the genome.…”

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confidence: 99%

Human Glyceraldehyde-3-phosphate Dehydrogenase Plays a Direct Role in Reactivating Oxidized Forms of the DNA Repair Enzyme APE1

Azam¹,

Jouvet

Jilani

et al. 2008

Journal of Biological Chemistry

122

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Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has diverse biological functions including its nuclear translocation in response to oxidative stress. We show that GAPDH physically associates with APE1, an essential enzyme involved in the repair of abasic sites in damaged DNA, as well as in the redox regulation of several transcription factors. This interaction allows GAPDH to convert the oxidized species of APE1 to the reduced form, thereby reactivating its endonuclease activity to cleave abasic sites. The GAPDH variants C152G and C156G retain the ability to interact with but are unable to reactivate APE1, implicating these cysteines in catalyzing the reduction of APE1. Interestingly, GAPDH-small interfering RNA knockdown sensitized the cells to methyl methane sulfonate and bleomycin, which generate lesions that are repaired by APE1, but showed normal sensitivity to 254-nm UV. Moreover, the GAPDH knockdown cells exhibited an increased level of spontaneous abasic sites in the genomic DNA as a result of diminished APE1 endonuclease activity. Thus, the nuclear translocation of GAPDH during oxidative stress constitutes a protective mechanism to safeguard the genome by preventing structural inactivation of APE1.The evolutionary conserved enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) 3 exists as a tetramer that catalyzes a critical reaction in the second stage of the glycolytic pathway (1). It uses the oxidized form of nicotinamide adenine dinucleotide (NAD ϩ ) and converts glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate with the concomitant release of NADH in an oxido-reduction reaction (1). GAPDH is also a key redox-sensitive protein that possesses an active site cysteine sulfhydryl that is susceptible to oxidation (2). Under oxidative stress, GAPDH rapidly undergoes disulfide bond formation leading to reduction in its enzymatic activity (2, 3). GAPDH has the propensity to interact with several proteins that are vulnerable to aggregation and are associated with neurodegenerative disorders such as in the case of the pro-oxidant amyloid ␤ peptide involved in Alzheimer disease (4). Recent studies have documented that GAPDH is also involved in several other nuclear processes that include histone H2B gene expression, nuclear RNA export, apoptosis, and cellular response to DNA damage (5-8).Several lines of evidence support a role for GAPDH in DNA damage and repair (5, 9). For example, GAPDH can translocate from the cytoplasm to the nucleus when cells are challenged with the potent chemical oxidant and DNA-damaging agent H 2 O 2 , although it is not clear what is the function executed by GAPDH under this stress condition (10). However, a more recent study documented that nitric oxide can also induce nuclear localization of GAPDH where it is acetylated by the acetyltransferase p300/CBP via direct protein interaction, which in turn causes stimulation of the catalytic activity of p300/CBP, resulting in the activation of downstream targets such as p53 (11). Other studies have shown that GAPDH is associated w...

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Identification of GAPDH as a protein target of the saframycin antiproliferative agents

Cited by 72 publications

References 27 publications

Analogs of Tetrahydroisoquinoline Natural Products That Inhibit Cell Migration and Target Galectin-3 Outside of Its Carbohydrate-binding Site

Analogs of Tetrahydroisoquinoline Natural Products That Inhibit Cell Migration and Target Galectin-3 Outside of Its Carbohydrate-binding Site

Chemistry of Ecteinascidins. Part 4: Preparation of 2′-<i>N</i>-Acyl Ecteinascidin 770 Derivatives with Improved Cytotoxicity Profiles

Human Glyceraldehyde-3-phosphate Dehydrogenase Plays a Direct Role in Reactivating Oxidized Forms of the DNA Repair Enzyme APE1

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