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Original article
SENP1 promotes hypoxia-induced cancer stemness by HIF-1α deSUMOylation and SENP1/HIF-1α positive feedback loop
  1. Chun-Ping Cui1,2,
  2. Carmen Chak-Lui Wong1,3,
  3. Alan Ka-Lun Kai1,
  4. Daniel Wai-Hung Ho1,3,
  5. Eunice Yuen-Ting Lau1,4,
  6. Yu-Man Tsui1,3,
  7. Lo-Kong Chan1,3,
  8. Tan-To Cheung3,5,
  9. Kenneth Siu-Ho Chok3,5,
  10. Albert C Y Chan3,5,
  11. Regina Cheuk-Lam Lo1,3,
  12. Joyce Man-Fong Lee1,
  13. Terence Kin-Wah Lee1,3,4,
  14. Irene Oi Lin Ng1,3
  1. 1Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
  2. 2State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China
  3. 3State Key Laboratory for Liver Research, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
  4. 4Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
  5. 5Department of Surgery, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
  1. Correspondence to Professor Irene Oi-Lin Ng, Room 127B, University Pathology Building, Queen Mary Hospital, Pokfulam, Hong Kong, Hong Kong; iolng{at}


Objective We investigated the effect and mechanism of hypoxic microenvironment and hypoxia-inducible factors (HIFs) on hepatocellular carcinoma (HCC) cancer stemness.

Design HCC cancer stemness was analysed by self-renewal ability, chemoresistance, expression of stemness-related genes and cancer stem cell (CSC) marker-positive cell population. Specific small ubiquitin-like modifier (SUMO) proteases 1 (SENP1) mRNA level was examined with quantitative PCR in human paired HCCs. Immunoprecipitation was used to examine the binding of proteins and chromatin immunoprecipitation assay to detect the binding of HIFs with hypoxia response element sequence. In vivo characterisation was performed in immunocompromised mice and stem cell frequency was analysed.

Results We showed that hypoxia enhanced the stemness of HCC cells and hepatocarcinogenesis through enhancing HIF-1α deSUMOylation by SENP1 and increasing stabilisation and transcriptional activity of HIF-1α. Furthermore, we demonstrated that SENP1 is a direct target of HIF-1/2α and a previously unrecognised positive feedback loop exists between SENP1 and HIF-1α.

Conclusions Taken together, our findings suggest the significance of this positive feedback loop between HIF-1α and SENP1 in contributing to the increased cancer stemness in HCC and hepatocarcinogenesis under hypoxia. Drugs that specifically target SENP1 may offer a potential novel therapeutic approach for HCC.


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  • Contributors C-PC and IOLN provided study concept and design. C-PC, CC-LW, AK-LK, DW-HH, EY-TL, Y-MT, TK-WL and IOLN collected and analysed the data. CPC, CCW, DWH, LKC, TKL and IOLN interpreted the data. C-PC, CC-LW, AK-LK, EY-TL, Y-MT, JM-FL and TK-WL performed the experiments. T-TC, KS-HC, ACYC, RC-LL and IOLN collected the patients' samples. C-PC and IOLN wrote the manuscript. All authors approved the final version of manuscript.

  • Funding This work was supported by the Hong Kong Research Grants Council (RGC) Theme-based Research Scheme (T12-704116-R), RGC General Research Fund (17111315), Hong Kong Scholars programme (81572373), SK Yee Medical Research Fund 2011 and Lee Shiu Family Foundation.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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