Physical Poster + E-Poster Presentation 34th Lorne Cancer Conference 2022

Characterisation of the effect of PRMT5 inhibitor (GSK3266595) on Pancreatic Ductal Adenocarcinoma (#157)

Michael KC Lee 1 2 3 , Lydia Lim 1 , Lorey Smith 1 , Jonathan Naddaf 1 , Laura Kirby 1 , Sean M Grimmond 2 , Grant A McArthur 1 3 , Karen E Sheppard 1 3 4
  1. Cancer Research Division, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  2. The University of Melbourne Centre for Cancer Research, University of Melbourne, Parkville, VIC, Australia
  3. Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
  4. Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, VIC, Australia

There is a strong clinical need for novel therapeutic options for pancreatic ductal adenocarcinoma (PDAC), where the 5-year overall survival remains poor at 15% with limited treatment options beyond chemotherapy (1, 2). Increased expression of PRMT5 in PDAC is associated with a worse prognosis and its inhibition in PDAC preclinical models have shown to be an effective therapy (3, 4). However, it remains unclear how the diverse number of cellular processes PRMT5 inhibition affects contribute to its role in cancer growth inhibition (5).  Interestingly, the more alternative splicing PRMT5 inhibition induces, the greater the effect on tumour growth inhibition (6, 7). Thus, this project aims to uncover the mechanism of action of PRMT5 inhibition in PDAC and in doing so advance the development of this novel therapeutic class (targeting alternative splicing) for this disease. To achieve this aim, we have performed whole transcriptome sequencing to determine time dependent PRMT5 inhibitor-induced differential mRNA expression and changes in pre-mRNA alternative splicing in two cell line models. These cell line models represent Moffitt’s basal (MiaPaca2) and classical (AsPC1) molecular subtype (8) where emerging evidences suggest there are subtype-specific responses.  In addition, a CRISPR screen was performed to assess genes necessary to respond to PRMT5 inhibition and potential mechanisms leading to synergistic growth inhibition. Updated analysis results combining both unbiased approaches will be presented which identify a list of relevant genes for functional validation towards uncovering PRMT5 inhibitor’s mechanism of action.

  1. 1. Latenstein AEJ, Van Roessel S, Van Der Geest LGM, Bonsing BA, Dejong CHC, Groot Koerkamp B, et al. Conditional Survival After Resection for Pancreatic Cancer: A Population-Based Study and Prediction Model. Annals of Surgical Oncology. 2020;27(7):2516-24.
  2. 2. Pishvaian MJ, Blais EM, Brody JR, Lyons E, Dearbeloa P, Hendifar A, et al. Overall survival in patients with pancreatic cancer receiving matched therapies following molecular profiling: a retrospective analysis of the Know Your Tumor registry trial. The Lancet Oncology. 2020;21(4):508-18.
  3. 3. Driehuis E, Van Hoeck A, Moore K, Kolders S, Francies HE, Gulersonmez MC, et al. Pancreatic cancer organoids recapitulate disease and allow personalized drug screening. Proceedings of the National Academy of Sciences. 2019;116(52):26580-90.
  4. 4. Qin Y, Hu Q, Xu J, Ji S, Dai W, Liu W, et al. PRMT5 enhances tumorigenicity and glycolysis in pancreatic cancer via the FBW7/cMyc axis. Cell Communication and Signaling. 2019;17(1).
  5. 5. Lee MKC, Grimmond SM, McArthur GA, Sheppard KE. PRMT5: An Emerging Target for Pancreatic Adenocarcinoma. 2021;13(20):5136.
  6. 6. Fedoriw A, Rajapurkar SR, O'Brien S, Gerhart SV, Mitchell LH, Adams ND, et al. Anti-tumor Activity of the Type I PRMT Inhibitor, GSK3368715, Synergizes with PRMT5 Inhibition through MTAP Loss. Cancer Cell. 2019;36(1):100-14.e25.
  7. 7. Gao G, Zhang L, Villarreal OD, He W, Su D, Bedford E, et al. PRMT1 loss sensitizes cells to PRMT5 inhibition. Nucleic Acids Research. 2019;47(10):5038-48.
  8. 8. Moffitt RA, Marayati R, Flate EL, Volmar KE, Loeza SGH, Hoadley KA, et al. Virtual microdissection identifies distinct tumor- and stroma-specific subtypes of pancreatic ductal adenocarcinoma. Nature Genetics. 2015;47:1168.