FL118, Acting As a 'molecular Glue Degrader', Binds to Dephosphorylates and Degrades the Oncoprotein DDX5 (p68) to Control C-Myc, Survivin and Mutant Kras Against Colorectal and Pancreatic Cancer with High Efficacy

Overview

Journal Clin Transl Med

Publisher Wiley

Specialty General Medicine

Date 2022 May 23

PMID 35604033

Authors

Xiang Ling

Wenjie Wu

Ieman A M Aljahdali

Jianqun Liao

Sreevidya Santha

Christos Fountzilas

Patrick M Boland

Fengzhi Li

Affiliations

Soon will be listed here.

Abstract

Background: Pancreatic ductal adenocarcinoma (PDAC), a difficult-to-treat cancer, is expected to become the second-largest cause of cancer-related deaths by 2030, while colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer deaths. Currently, there is no effective treatment for PDAC patients. The development of novel agents to effectively treat these cancers remains an unmet clinical need. FL118, a novel anticancer small molecule, exhibits high efficacy against cancers; however, the direct biochemical target of FL118 is unknown.

Methods: FL118 affinity purification, mass spectrometry, Nanosep centrifugal device and isothermal titration calorimetry were used for identifying and confirming FL118 binding to DDX5/p68 and its binding affinity. Immunoprecipitation (IP), western blots, real-time reverse transcription PCR, gene silencing, overexpression (OE) and knockout (KO) were used for analysing gene/protein function and expression. Chromatin IP was used for analysing protein-DNA interactions. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromid assay and human PDAC/CRC cell/tumour models were used for determining PDAC/CRC cell/tumour in vitro and in vivo growth.

Results: We discovered that FL118 strongly binds to dephosphorylates and degrades the DDX5 oncoprotein via the proteasome degradation pathway without decreasing DDX5 mRNA. Silencing and OE of DDX5 indicated that DDX5 is a master regulator for controlling the expression of multiple oncogenic proteins, including survivin, Mcl-1, XIAP, cIAP2, c-Myc and mutant Kras. Genetic manipulation of DDX5 in PDAC cells affects tumour growth. PDAC cells with DDX5 KO are resistant to FL118 treatment. Our human tumour animal model studies further indicated that FL118 exhibits high efficacy to eliminate human PDAC and CRC tumours that have a high expression of DDX5, while FL118 exhibits less effectiveness in PDAC and CRC tumours with low DDX5 expression.

Conclusion: DDX5 is a bona fide FL118 direct target and can act as a biomarker for predicting PDAC and CRC tumour sensitivity to FL118. This would greatly impact FL118 precision medicine for patients with advanced PDAC or advanced CRC in the clinic. FL118 may act as a 'molecular glue degrader' to directly glue DDX5 and ubiquitination regulators together to degrade DDX5.

Citing Articles

Novel Camptothecin Derivative 9c with Enhanced Antitumor Activity via NSA2-EGFR-P53 Signaling Pathway.

Du F, Zhang A, Qi X, Yin R, Jiang T, Li J Int J Mol Sci. 2025; 26(5).

PMID: 40076615 PMC: 11900506. DOI: 10.3390/ijms26051987.

Clinically and orally compatible formulation-manufactured DDX5 (p68)-targeting molecular glue FL118 products exhibit low toxicity but high efficacy against human cancer.

Ling X, Wu W, Yan L, Curtin L, Farrauto M, Sexton S J Pharm Anal. 2025; 14(11):101001.

PMID: 39759975 PMC: 11696646. DOI: 10.1016/j.jpha.2024.101001.

Delineating MYC-Mediated Escape Mechanisms from Conventional and T Cell-Redirecting Therapeutic Antibodies.

de Jonge A, Csikos T, Eken M, Bulthuis E, Poddighe P, Roemer M Int J Mol Sci. 2024; 25(22).

PMID: 39596160 PMC: 11594070. DOI: 10.3390/ijms252212094.

FL118 Is a Potent Therapeutic Agent against Chronic Myeloid Leukemia Resistant to BCR-ABL Inhibitors through Targeting RNA Helicase DDX5.

Takeda K, Ohta S, Nagao M, Kobayashi E, Tago K, Funakoshi-Tago M Int J Mol Sci. 2024; 25(7).

PMID: 38612503 PMC: 11011477. DOI: 10.3390/ijms25073693.

The involvement of E3 ubiquitin ligases in the development and progression of colorectal cancer.

Chen J, Feng H, Wang Y, Bai X, Sheng S, Li H Cell Death Discov. 2023; 9(1):458.

PMID: 38104139 PMC: 10725464. DOI: 10.1038/s41420-023-01760-z.

References

Tagen M, Zhuang Y, Zhang F, Harstead K, Shen J, Schaiquevich P . P-glycoprotein, but not multidrug resistance protein 4, plays a role in the systemic clearance of irinotecan and SN-38 in mice. Drug Metab Lett. 2010; 4(4):195-201. PMC: 4486004. DOI: 10.2174/187231210792928251. View

Gargano B, Amente S, Majello B, Lania L . P-TEFb is a crucial co-factor for Myc transactivation. Cell Cycle. 2007; 6(16):2031-7. DOI: 10.4161/cc.6.16.4554. View

Saporita A, Chang H, Winkeler C, Apicelli A, Kladney R, Wang J . RNA helicase DDX5 is a p53-independent target of ARF that participates in ribosome biogenesis. Cancer Res. 2011; 71(21):6708-17. PMC: 3206203. DOI: 10.1158/0008-5472.CAN-11-1472. View

Zhao J, Ling X, Cao S, Liu X, Wan S, Jiang T . Antitumor activity of FL118, a survivin, Mcl-1, XIAP, and cIAP2 selective inhibitor, is highly dependent on its primary structure and steric configuration. Mol Pharm. 2013; 11(2):457-67. DOI: 10.1021/mp4004282. View

Zhang M, Weng W, Zhang Q, Wu Y, Ni S, Tan C . The lncRNA NEAT1 activates Wnt/β-catenin signaling and promotes colorectal cancer progression via interacting with DDX5. J Hematol Oncol. 2018; 11(1):113. PMC: 6125951. DOI: 10.1186/s13045-018-0656-7. View

Yang L, Lin C, Liu Z . P68 RNA helicase mediates PDGF-induced epithelial mesenchymal transition by displacing Axin from beta-catenin. Cell. 2006; 127(1):139-55. DOI: 10.1016/j.cell.2006.08.036. View

Ling X, Wu W, Fan C, Xu C, Liao J, Rich L . An ABCG2 non-substrate anticancer agent FL118 targets drug-resistant cancer stem-like cells and overcomes treatment resistance of human pancreatic cancer. J Exp Clin Cancer Res. 2018; 37(1):240. PMC: 6169080. DOI: 10.1186/s13046-018-0899-8. View

Ling X, Liu X, Zhong K, Smith N, Prey J, Li F . FL118, a novel camptothecin analogue, overcomes irinotecan and topotecan resistance in human tumor xenograft models. Am J Transl Res. 2015; 7(10):1765-81. PMC: 4656756. View

Wang D, Huang J, Hu Z . RNA helicase DDX5 regulates microRNA expression and contributes to cytoskeletal reorganization in basal breast cancer cells. Mol Cell Proteomics. 2011; 11(2):M111.011932. PMC: 3277758. DOI: 10.1074/mcp.M111.011932. View

10.

Wang R, Bao H, Du W, Chen X, Liu H, Han D . P68 RNA helicase promotes invasion of glioma cells through negatively regulating DUSP5. Cancer Sci. 2018; 110(1):107-117. PMC: 6317933. DOI: 10.1111/cas.13858. View

11.

Yang Z, Yik J, Chen R, He N, Jang M, Ozato K . Recruitment of P-TEFb for stimulation of transcriptional elongation by the bromodomain protein Brd4. Mol Cell. 2005; 19(4):535-45. DOI: 10.1016/j.molcel.2005.06.029. View

12.

Plenge R . Disciplined approach to drug discovery and early development. Sci Transl Med. 2016; 8(349):349ps15. DOI: 10.1126/scitranslmed.aaf2608. View

13.

Kapoor R, Slade D, Fujimori A, Pommier Y, Harker W . Altered topoisomerase I expression in two subclones of human CEM leukemia selected for resistance to camptothecin. Oncol Res. 1995; 7(2):83-95. View

14.

Cohen A, Geva-Zatorsky N, Eden E, Frenkel-Morgenstern M, Issaeva I, Sigal A . Dynamic proteomics of individual cancer cells in response to a drug. Science. 2008; 322(5907):1511-6. DOI: 10.1126/science.1160165. View

15.

Rahl P, Lin C, Seila A, Flynn R, McCuine S, Burge C . c-Myc regulates transcriptional pause release. Cell. 2010; 141(3):432-45. PMC: 2864022. DOI: 10.1016/j.cell.2010.03.030. View

16.

Yang L, Lin C, Sun S, Zhao S, Liu Z . A double tyrosine phosphorylation of P68 RNA helicase confers resistance to TRAIL-induced apoptosis. Oncogene. 2007; 26(41):6082-92. DOI: 10.1038/sj.onc.1210427. View

17.

Barboric M, Nissen R, Kanazawa S, Jabrane-Ferrat N, Peterlin B . NF-kappaB binds P-TEFb to stimulate transcriptional elongation by RNA polymerase II. Mol Cell. 2001; 8(2):327-37. DOI: 10.1016/s1097-2765(01)00314-8. View

18.

Pellegata N, Sessa F, Renault B, Bonato M, Leone B, Solcia E . K-ras and p53 gene mutations in pancreatic cancer: ductal and nonductal tumors progress through different genetic lesions. Cancer Res. 1994; 54(6):1556-60. View

19.

Li F, Ambrosini G, Chu E, Plescia J, Tognin S, Marchisio P . Control of apoptosis and mitotic spindle checkpoint by survivin. Nature. 1998; 396(6711):580-4. DOI: 10.1038/25141. View

20.

Ling X, Cao S, Cheng Q, Keefe J, Rustum Y, Li F . A novel small molecule FL118 that selectively inhibits survivin, Mcl-1, XIAP and cIAP2 in a p53-independent manner, shows superior antitumor activity. PLoS One. 2012; 7(9):e45571. PMC: 3446924. DOI: 10.1371/journal.pone.0045571. View