Phosphomimetic Dicer S1016E triggers a switch to glutamine metabolism in gemcitabine-resistant pancreatic cancer

Ji Min Park; Jei-Ming Peng; Yu-Shiuan Shen; Chia-Ying Lin; Tung-Wei Hsu; Yen-Hao Su; Hsin-An Chen; Charupong Saengboonmee; Jung-Su Chang; Ching-Feng Chiu; Yan-Shen Shan

doi:10.1016/j.molmet.2022.101576

Phosphomimetic Dicer S1016E triggers a switch to glutamine metabolism in gemcitabine-resistant pancreatic cancer

Mol Metab. 2022 Nov:65:101576. doi: 10.1016/j.molmet.2022.101576. Epub 2022 Aug 19.

Authors

Affiliations

¹ Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan; Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli, Taiwan; Taipei Medical University and Affiliated Hospitals Pancreatic Cancer Groups, Taipei Cancer Center, Taipei Medical University, Taiwan.
² Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan.
³ Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan.
⁴ Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Division of General Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
⁵ Taipei Medical University and Affiliated Hospitals Pancreatic Cancer Groups, Taipei Cancer Center, Taipei Medical University, Taiwan; Division of General Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Taipei Medical University Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan; TMU Research Center for Digestive Medicine, Taipei Medical University, Taipei, Taiwan.
⁶ Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
⁷ Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan; TMU Research Center for Digestive Medicine, Taipei Medical University, Taipei, Taiwan; Nutrition Research Center, Taipei Medical University Hospital, Taipei, Taiwan.
⁸ Graduate Institute of Metabolism and Obesity Sciences, Taipei Medical University, Taipei, Taiwan; Taipei Medical University and Affiliated Hospitals Pancreatic Cancer Groups, Taipei Cancer Center, Taipei Medical University, Taiwan; Taipei Medical University Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan; TMU Research Center for Digestive Medicine, Taipei Medical University, Taipei, Taiwan; Nutrition Research Center, Taipei Medical University Hospital, Taipei, Taiwan. Electronic address: chiucf@tmu.edu.tw.
⁹ Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.

Abstract

Objective: Dicer is an enzyme that processes microRNAs (miRNAs) precursors into mature miRNAs, which have been implicated in various aspects of cancer progressions, such as clinical aggressiveness, prognosis, and survival outcomes. We previously showed that high expression of Dicer is associated with gemcitabine (GEM) resistance in pancreatic ductal adenocarcinoma (PDAC); thus, in this study, we aimed to focus on how Dicer is involved in GEM resistance in PDAC, including cancer prognosis, cell proliferation, and metabolic regulation.

Methods: We generated stable shRNA knockdown of Dicer in GEM-resistant PANC-1 (PANC-1 GR) cells and explored cell viability by MTT and clonogenicity assays. Metabolomic profiling was employed to investigate metabolic changes between parental cells, PANC-1, and PANC-1 GR cells, and further implied to compare their sensitivity to the glutaminase inhibitor, CB839, and GEM treatments. To identify putative phosphorylation site involves with Dicer and its effects on GEM resistance in PDAC cells, we further generated phosphomimetic or phosphomutant Dicer at S1016 site and examined the changes in drug sensitivity, metabolic alteration, and miRNA regulation.

Results: We observed that high Dicer levels in pancreatic ductal adenocarcinoma cells were positively correlated with advanced pancreatic cancer and acquired resistance to GEM. Metabolomic analysis indicated that PANC-1 GR cells rapidly utilised glutamine as their major fuel and increased levels of glutaminase (GLS): glutamine synthetase (GLUL) ratio which is related to high Dicer expression. In addition, we found that phosphomimetic Dicer S1016E but not phosphomutant Dicer S1016A facilitated miRNA maturation, causing an imbalance in GLS and GLUL and resulting in an increased response to GLS inhibitors.

Conclusion: Our results suggest that phosphorylation of Dicer on site S1016 affects miRNA biogenesis and glutamine metabolism in GEM-resistant pancreatic cancer.

Keywords: Dicer phosphorylation; Gemcitabine resistance; Glutamine metabolism; Pancreatic ductal adenocarcinoma; miRNA biogenesis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antimetabolites, Antineoplastic / pharmacology
Antimetabolites, Antineoplastic / therapeutic use
Carcinoma, Pancreatic Ductal* / drug therapy
Carcinoma, Pancreatic Ductal* / genetics
Carcinoma, Pancreatic Ductal* / metabolism
Cell Line, Tumor
DEAD-box RNA Helicases* / genetics
Deoxycytidine / analogs & derivatives
Drug Resistance, Neoplasm / genetics
Gemcitabine
Glutamate-Ammonia Ligase / pharmacology
Glutaminase / genetics
Glutaminase / pharmacology
Glutaminase / therapeutic use
Glutamine
Humans
MicroRNAs* / genetics
Pancreatic Neoplasms* / drug therapy
Pancreatic Neoplasms* / genetics
Pancreatic Neoplasms* / metabolism
RNA, Small Interfering
Ribonuclease III* / genetics

Substances

Antimetabolites, Antineoplastic
MicroRNAs
RNA, Small Interfering
Glutamine
Deoxycytidine
DICER1 protein, human
Ribonuclease III
Glutaminase
DEAD-box RNA Helicases
Glutamate-Ammonia Ligase
Gemcitabine