UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation
Abstract Background Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patien...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2020-10-01
|
| Series: | Journal of Experimental & Clinical Cancer Research |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13046-020-01734-4 |
| _version_ | 1811323816633171968 |
|---|---|
| author | Jingyuan Sun Zhenru Zhu Wenwen Li Mengying Shen Chuanhui Cao Qingcan Sun Zeqin Guo Li Liu Dehua Wu |
| author_facet | Jingyuan Sun Zhenru Zhu Wenwen Li Mengying Shen Chuanhui Cao Qingcan Sun Zeqin Guo Li Liu Dehua Wu |
| author_sort | Jingyuan Sun |
| collection | DOAJ |
| description | Abstract Background Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patients. However, the underlying mechanism have not been clearly understood. Methods We obtained 7 pairs of HCC tissues and corresponding non-tumor tissues, and UBE2T was identified as one of the most upregulated genes. The radioresistant role of UBE2T was examined by colony formation assays in vitro and xenograft tumor models in vivo. Comet assay, cell cycle flow cytometry and γH2AX foci measurement were used to investigate the mechanism by which UBE2T mediating DDR. Chromatin fractionation and immunofluorescence staining were used to assess cell cycle checkpoint kinase 1(CHK1) activation. Finally, we analyzed clinical data from HCC patients to verify the function of UBE2T. Results Here, we found that ubiquitin-conjugating enzyme E2T (UBE2T) was upregulated in HCC tissues, and the HCC patients with higher UBE2T levels exhibited poorer outcomes. Functional studies indicated that UBE2T increased HCC radioresistance in vitro and in vivo. Mechanistically, UBE2T-RNF8, was identified as the E2-E3 pair, physically bonded with and monoubiquitinated histone variant H2AX/γH2AX upon radiation exposure. UBE2T-regulated H2AX/γH2AX monoubiquitination facilitated phosphorylation of CHK1 for activation and CHK1 release from the chromatin to cytosol for degradation. The interruption of UBE2T-mediated monoubiquitination on H2AX/γH2AX, including E2-enzyme-deficient mutation (C86A) of UBE2T and monoubiquitination-site-deficient mutation (K119/120R) of H2AX, cannot effectively activate CHK1. Moreover, genetical and pharmacological inhibition of CHK1 impaired the radioresistant role of UBE2T in HCC. Furthermore, clinical data suggested that the HCC patients with higher UBE2T levels exhibited worse response to radiotherapy. Conclusion Our results revealed a novel role of UBE2T-mediated H2AX/γH2AX monoubiquitination on facilitating cell cycle arrest activation to provide sufficient time for radiation-induced DNA repair, thus conferring HCC radioresistance. This study indicated that disrupting UBE2T-H2AX-CHK1 pathway maybe a promising potential strategy to overcome HCC radioresistance. |
| first_indexed | 2024-04-13T14:02:07Z |
| format | Article |
| id | doaj.art-529bd8874b91413e94b3b4344b489804 |
| institution | Directory Open Access Journal |
| issn | 1756-9966 |
| language | English |
| last_indexed | 2024-04-13T14:02:07Z |
| publishDate | 2020-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Experimental & Clinical Cancer Research |
| spelling | doaj.art-529bd8874b91413e94b3b4344b4898042022-12-22T02:44:01ZengBMCJournal of Experimental & Clinical Cancer Research1756-99662020-10-0139111810.1186/s13046-020-01734-4UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activationJingyuan Sun0Zhenru Zhu1Wenwen Li2Mengying Shen3Chuanhui Cao4Qingcan Sun5Zeqin Guo6Li Liu7Dehua Wu8Department of Radiation Oncology, Nanfang Hospital, Southern Medical UniversityDepartment of Radiation Oncology, Nanfang Hospital, Southern Medical UniversityHepatology Unit and Department of Infectious Diseases, Nanfang Hospital, Southern Medical UniversityHepatology Unit and Department of Infectious Diseases, Nanfang Hospital, Southern Medical UniversityDepartment of Radiation Oncology, Nanfang Hospital, Southern Medical UniversityHepatology Unit and Department of Infectious Diseases, Nanfang Hospital, Southern Medical UniversityDepartment of Radiation Oncology, Nanfang Hospital, Southern Medical UniversityHepatology Unit and Department of Infectious Diseases, Nanfang Hospital, Southern Medical UniversityDepartment of Radiation Oncology, Nanfang Hospital, Southern Medical UniversityAbstract Background Radioresistance is the major obstacle in radiation therapy (RT) for hepatocellular carcinoma (HCC). Dysregulation of DNA damage response (DDR), which includes DNA repair and cell cycle checkpoints activation, leads to radioresistance and limits radiotherapy efficacy in HCC patients. However, the underlying mechanism have not been clearly understood. Methods We obtained 7 pairs of HCC tissues and corresponding non-tumor tissues, and UBE2T was identified as one of the most upregulated genes. The radioresistant role of UBE2T was examined by colony formation assays in vitro and xenograft tumor models in vivo. Comet assay, cell cycle flow cytometry and γH2AX foci measurement were used to investigate the mechanism by which UBE2T mediating DDR. Chromatin fractionation and immunofluorescence staining were used to assess cell cycle checkpoint kinase 1(CHK1) activation. Finally, we analyzed clinical data from HCC patients to verify the function of UBE2T. Results Here, we found that ubiquitin-conjugating enzyme E2T (UBE2T) was upregulated in HCC tissues, and the HCC patients with higher UBE2T levels exhibited poorer outcomes. Functional studies indicated that UBE2T increased HCC radioresistance in vitro and in vivo. Mechanistically, UBE2T-RNF8, was identified as the E2-E3 pair, physically bonded with and monoubiquitinated histone variant H2AX/γH2AX upon radiation exposure. UBE2T-regulated H2AX/γH2AX monoubiquitination facilitated phosphorylation of CHK1 for activation and CHK1 release from the chromatin to cytosol for degradation. The interruption of UBE2T-mediated monoubiquitination on H2AX/γH2AX, including E2-enzyme-deficient mutation (C86A) of UBE2T and monoubiquitination-site-deficient mutation (K119/120R) of H2AX, cannot effectively activate CHK1. Moreover, genetical and pharmacological inhibition of CHK1 impaired the radioresistant role of UBE2T in HCC. Furthermore, clinical data suggested that the HCC patients with higher UBE2T levels exhibited worse response to radiotherapy. Conclusion Our results revealed a novel role of UBE2T-mediated H2AX/γH2AX monoubiquitination on facilitating cell cycle arrest activation to provide sufficient time for radiation-induced DNA repair, thus conferring HCC radioresistance. This study indicated that disrupting UBE2T-H2AX-CHK1 pathway maybe a promising potential strategy to overcome HCC radioresistance.http://link.springer.com/article/10.1186/s13046-020-01734-4Ubiquitin-conjugating enzyme E2TH2AX monoubiquitinationCell cycle arrestRadioresistanceHepatocellular carcinoma |
| spellingShingle | Jingyuan Sun Zhenru Zhu Wenwen Li Mengying Shen Chuanhui Cao Qingcan Sun Zeqin Guo Li Liu Dehua Wu UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation Journal of Experimental & Clinical Cancer Research Ubiquitin-conjugating enzyme E2T H2AX monoubiquitination Cell cycle arrest Radioresistance Hepatocellular carcinoma |
| title | UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation |
| title_full | UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation |
| title_fullStr | UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation |
| title_full_unstemmed | UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation |
| title_short | UBE2T-regulated H2AX monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating CHK1 activation |
| title_sort | ube2t regulated h2ax monoubiquitination induces hepatocellular carcinoma radioresistance by facilitating chk1 activation |
| topic | Ubiquitin-conjugating enzyme E2T H2AX monoubiquitination Cell cycle arrest Radioresistance Hepatocellular carcinoma |
| url | http://link.springer.com/article/10.1186/s13046-020-01734-4 |
| work_keys_str_mv | AT jingyuansun ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT zhenruzhu ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT wenwenli ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT mengyingshen ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT chuanhuicao ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT qingcansun ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT zeqinguo ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT liliu ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation AT dehuawu ube2tregulatedh2axmonoubiquitinationinduceshepatocellularcarcinomaradioresistancebyfacilitatingchk1activation |