A novel probe for spliceosomal proteins that induces autophagy and death of melanoma cells reveals new targets for melanoma drug discovery Article

Palrasu, M, Knapinska, AM, Diez, J et al. (2019). A novel probe for spliceosomal proteins that induces autophagy and death of melanoma cells reveals new targets for melanoma drug discovery . CELLULAR PHYSIOLOGY AND BIOCHEMISTRY, 53(4), 656-686. 10.33594/000000164

cited authors

  • Palrasu, M; Knapinska, AM; Diez, J; Smith, L; LaVoi, T; Giulianotti, M; Houghten, RA; Fields, GB; Minond, D

abstract

  • Background/Aims: Despite recent advances in melanoma drug discovery, the average overall survival of patients with late stage metastatic melanoma is approximately 3 years, suggesting a need for approaches that identify new melanoma targets. We have previously reported a discovery of novel anti-melanoma compound 2155-14 (Onwuha-Ekpete et al., J Med Chem. 2014 Feb 27; 57(4):1599-608). In the report presented herein we aim to identify its target(s) and mechanism of action. Methods: We utilized biotinylated analog of 2155-14 to pull down its targets from melanoma cells. Proteomics in combination with western blot were used to identify the targets. Mechanism of action of 2155-14 was determined using flow cytometry, RT-PCR, microscopy, western blot, and enzymatic activity assays. Where applicable, one-way analysis of variance (ANOVA) was used followed by Dunnett post hoc test. Results: In the present study, we identified ATP-dependent RNA helicase DDX1 and heterogeneous nuclear ribonucleoproteins (hnRNPs) H1, H2 and A2/B1 as targets of anti-melanoma compound 2155-14. To the best of our knowledge, this is a first report suggesting that these proteins could be targeted for melanoma therapy. Mechanistic investigations showed that 2155-14 induces ER stress leading to potentiation of basal autophagy resulting in melanoma cell death in BRAF and NRAS mutated melanoma cells. Conclusion: Identification of mode of action of 2155-14 may provide insight into novel therapies against a broad range of melanoma subtypes. These studies were enabled by the novel probe derived from a mixture-based library, an important class of chemical biology tools for discovering novel targets.

publication date

  • January 1, 2019

published in

Digital Object Identifier (DOI)

start page

  • 656

end page

  • 686

volume

  • 53

issue

  • 4