Context-dependent function of the deubiquitinating enzyme USP9X in pancreatic ductal adenocarcinoma.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and deadly malignancies. Recently, the deubiquitinating protease USP9X has been shown to behave as an oncogene in a number of neoplasms, including those of breast, brain, colon, esophagus and lung, as well as KRAS wild-type PDAC. However, other studies suggest that USP9X may function as a tumor-suppressor in a murine PDAC model when USP9X expression is depleted during early pancreatic development. To address the conflicting findings surrounding the role of USP9X in PDAC, we examined the effects of knocking down USP9X in five human PDAC cell lines (BxPC3, Capan1, CD18, Hs766T, and S2-013). We demonstrate that knocking down USP9X in each of the PDAC cell lines reduces their anchorage-dependent growth. Using an inducible shRNA system to knock down USP9X in both BxPC3 and Capan1 cells, we also determined that USP9X is necessary for the anchorage-independent growth. In addition, knockdown of USP9X alters the cell cycle profile of BxPC3 cells and increases their invasive capacity. Finally, we show that an inhibitor of deubiquitinating proteases, WP1130, induces significant cytotoxicity in each of the five PDAC cell lines tested. Overall, our work and the work of others indicate that the function and role of USP9X is highly context-dependent. Although USP9X may function as a tumor-suppressor during the establishment of PDAC, data presented here argue that USP9X promotes cell growth in advanced PDAC cells when PDAC is typically diagnosed. Hence, USP9X may be a promising therapeutic target for the treatment of advanced PDAC.
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Jesse L
JL
Cox
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Phillip J
PJ
Wilder
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Erin L
EL
Wuebben
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Michel M
MM
Ouellette
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Michael A
MA
Hollingsworth
Eppley Institute for Research in Cancer and Allied Diseases; Fred & Pamela Buffett Cancer Center; University of Nebraska Medical Center; Omaha, NE USA.
Angie
A
Rizzino
D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D003487:Cyanoacrylates; D006801:Humans; D009361:Neoplasm Invasiveness; D009570:Nitriles / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011480:Protease Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D012097:Repressor Proteins / Q000378:metabolism; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D054875:Ubiquitination
D003487:Cyanoacrylates; D009570:Nitriles; D011480:Protease Inhibitors; D011725:Pyridines; D012097:Repressor Proteins; C506234:USP9X protein, human; C519751:degrasyn; C432966:ITCH protein, human; D044767:Ubiquitin-Protein Ligases; D043222:Ubiquitin Thiolesterase
KRAS; USP9X; WP1130; deubiquitinating protease; oncogene; pancreatic ductal adenocarcinoma; tumor suppressor gene