nsc-74859 and Neoplasms

Topics: Animals; Antineoplastic Agents; Clinical Trials as Topic; Drug Design; High-Throughput Screening Assays; Humans; Neoplasms; Peptides; Peptidomimetics; Psoriasis; Signal Transduction; STAT3 Transcription Factor; Stem Cells; Structure-Activity Relationship

In order to regulate the activity of P5, which is a member of the protein disulfide isomerase family, we screened a chemical compound library for P5-specific inhibitors, and identified two candidate compounds (anacardic acid and NSC74859). Interestingly, anacardic acid inhibited the reductase activity of P5, but did not inhibit the activity of protein disulfide isomerase (PDI), thiol-disulfide oxidoreductase ERp57, or thioredoxin. NSC74859 inhibited all these enzymes. When we examined the effects of these compounds on the secretion of soluble major histocompatibility complex class-I-related gene A (MICA) from cancer cells, anacardic acid was found to decrease secretion. In addition, anacardic acid was found to reduce the concentration of glutathione up-regulated by the anticancer drug 17-demethoxygeldanamycin in cancer cells. These results suggest that anacardic acid can both inhibit P5 reductase activity and decrease the secretion of soluble MICA from cancer cells. It might be a novel and potent anticancer treatment by targeting P5 on the surface of cancer cells.

Topics: Aminosalicylic Acids; Anacardic Acids; Benzenesulfonates; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Drug Discovery; Enzyme Inhibitors; HCT116 Cells; HeLa Cells; Histocompatibility Antigens Class I; Humans; Molecular Docking Simulation; Neoplasms; Protein Disulfide-Isomerases; Structure-Activity Relationship

Topics: Aminosalicylic Acids; Benzenesulfonates; Cell Proliferation; Dimerization; Humans; Models, Molecular; Neoplasms; Salicylic Acid; Signal Transduction; Small Molecule Libraries; STAT3 Transcription Factor

S3I-201 (NSC 74859) is a chemical probe inhibitor of Stat3 activity, which was identified from the National Cancer Institute chemical libraries by using structure-based virtual screening with a computer model of the Stat3 SH2 domain bound to its Stat3 phosphotyrosine peptide derived from the x-ray crystal structure of the Stat3beta homodimer. S3I-201 inhibits Stat3.Stat3 complex formation and Stat3 DNA-binding and transcriptional activities. Furthermore, S3I-201 inhibits growth and induces apoptosis preferentially in tumor cells that contain persistently activated Stat3. Constitutively dimerized and active Stat3C and Stat3 SH2 domain rescue tumor cells from S3I-201-induced apoptosis. Finally, S3I-201 inhibits the expression of the Stat3-regulated genes encoding cyclin D1, Bcl-xL, and survivin and inhibits the growth of human breast tumors in vivo. These findings strongly suggest that the antitumor activity of S3I-201 is mediated in part through inhibition of aberrant Stat3 activation and provide the proof-of-concept for the potential clinical use of Stat3 inhibitors such as S3I-201 in tumors harboring aberrant Stat3.

Topics: Aminosalicylic Acid; Aminosalicylic Acids; Animals; Antineoplastic Agents; Apoptosis; Benzenesulfonates; Cell Line; Computational Biology; DNA; Drug Evaluation, Preclinical; Gene Expression Regulation; Humans; Mice; Models, Molecular; Neoplasms; Phosphotyrosine; Protein Binding; Protein Structure, Tertiary; STAT3 Transcription Factor; Transcription, Genetic; Xenograft Model Antitumor Assays