Description
Pancreatic cancer patient survival is the lowest of all common cancers. Given that pancreatic cancer therapies do little to improve survival, there is a significant need to identify additional potential therapeutic targets and treatment strategies. The ROCK1 locus on chromosome 18 is amplified in 15% of pancreatic patient tumors (Biankin et al. 2012), accompanied by concordant copy number/gene expression changes (Bailey et al. 2016). The ROCK1 and ROCK2 kinases promote actomyosin contractility through phosphorylation of substrates including the myosin regulatory light chain 2 (MLC2), myosin-binding subunit of the MLC phosphatase (MYPT1) and LIM kinases 1&2 (Rath and Olson 2012, Julian and Olson 2014). In addition to direct effects on the organization and dynamics of the actin cytoskeleton that impact cell morphology, ROCK-mediated cell contractility also affects gene transcription (Sanz-Moreno et al. 2011). How ROCK-mediated actomyosin contractility might contribute to pancreatic cancer by altering gene expression has not been established.In this study, mouse pancreatic ductal adenocarcinoma tumour cells were transduced with retrovirus encoding conditionally-activated estrogen-receptor hormone-binding domain (hbER) fusions with ROCK1 (ROCK1:ER) or ROCK2 (ROCK2:ER) kinase domains, or green fluorescent protein (GFP:ER). GFP:ER expressing cells were treated with ethanol vehicle or 1 micromolar 4-hydroxytamoxifen (4HT) to identify any effects of the estrogen analogue, while ROCK1:ER and ROCK2:ER cells were treated with 1 micromolar 4HT to activate the ER fusion proteins. RNA was isolated, and enriched for poly A+ transcripts prior to sequencing.Bailey, P., et al. (2016). Nature 531: 47-52.Biankin, A. V., et al. (2012). Nature 491: 399-405.Julian, L. and M. F. Olson (2014). Small GTPases 5: e29846.Rath, N. and M. F. Olson (2012). EMBO Rep 13: 900-908.Sanz-Moreno, V., et al. (2011). Cancer Cell 20: 229-245.