1
|
Histone Methyltransferase G9a-Promoted Progression of Hepatocellular Carcinoma Is Targeted by Liver-Specific Hsa-miR-122. Cancers (Basel) 2021; 13:cancers13102376. [PMID: 34069116 PMCID: PMC8157135 DOI: 10.3390/cancers13102376] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Targeting epigenetic alterations in hepatocellular carcinoma (HCC) provides therapeutic options in addition to traditional treatments. The aim of our study was to evaluate the potential of targeting histone methyltransferase G9a in the development of a therapeutic target. We confirmed the prognostic values of mRNA and protein levels of G9a expression in HCC respectively from public database and tissue microarray. We also confirmed the aggressive phenotypes supported by G9a in both HBV+ and HBV− HCC cells. The identification of a regulation axis between liver-specific tumor suppressor miR-122 and G9a further supported the important roles of G9a during the tumorigenesis and progression of HCC. Combination of lower miR-122 and higher G9a levels may provide prognostic potential for poor clinical outcomes and therapeutic potential for epigenetic targeting therapies. Abstract Hepatocellular carcinoma (HCC) accounts for the majority of primary liver cancers, which is the second most lethal tumor worldwide. Epigenetic deregulation is a common trait observed in HCC. Recently, increasing evidence suggested that the G9a histone methyltransferase might be a novel regulator of HCC development. However, several HCC cell lines were recently noted to have HeLa cell contamination or to have been derived from non-hepatocellular origin, suggesting that functional validation of G9a in proper HCC models is still required. Herein, we first confirmed that higher G9a messenger RNA and protein expression levels were correlated with poor overall survival (OS) and disease-free survival (DFS) rates of HCC patients from The Cancer Genome Atlas (TCGA) dataset and our recruited HCC cohort. In an in vitro functional evaluation of HCC cells, HCC36 (hepatitis B virus-positive (HBV+) and Mahlavu (HBV−)) cells showed that G9a participated in promoting cell proliferation, colony formation, and migration/invasion abilities. Moreover, orthotopic inoculation of G9a-depleted Mahlavu cells in NOD-SCID mice also resulted in a significantly decreased tumor burden compared to the control group. Furthermore, after surveying microRNA (miRNA; miR) prediction databases, we identified the liver-specific miR-122 as a G9a-targeting miRNA. In various HCC cell lines, we observed that miR-122 expression levels tended to be inversely correlated to G9a expression levels. In clinical HCC specimens, a significant inverse correlation of miR-122 and G9a mRNA expression levels was also observed. Functionally, the colony formation and invasive ability were attenuated in miR-122-overexpressing HCC cells. HCC patients with low miR-122 and high G9a expression levels had the worst OS and DFS rates compared to others. Together, our results confirmed the importance of altered G9a expression during HCC progression and discovered that a novel liver-specific miR-122-G9a regulatory axis exists.
Collapse
|
2
|
Kuo TC, Chen CK, Hua KT, Yu P, Lee WJ, Chen MW, Jeng YM, Chien MH, Kuo KT, Hsiao M, Kuo ML. Glutaminase 2 stabilizes Dicer to repress Snail and metastasis in hepatocellular carcinoma cells. Cancer Lett 2016; 383:282-294. [PMID: 27725225 DOI: 10.1016/j.canlet.2016.10.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/22/2016] [Accepted: 10/03/2016] [Indexed: 01/05/2023]
Abstract
Glutaminolysis that catabolizes glutamine to glutamate plays a critical role in cancer progression. Glutaminase 2 (GLS2) has been reported as a tumor suppressor. Recent studies implied that GLS2 may display its multifunction besides classical metabolic feature by different localizations and potential protein binding domains. Here, we showed that GLS2 expression correlates inversely with stage, vascular invasion, tumor size and poor prognosis in human hepatocellular carcinoma (HCC) tissues. We found that GLS2 significantly represses cell migration, invasion and metastasis of HCC through downregulation of Snail in vitro and in vivo. Moreover, our results demonstrated that GLS2 interacts with Dicer and stabilizes Dicer protein to facilitate miR-34a maturation and subsequently represses Snail expression in a glutaminase activity independent manner. Our findings indicate that non-glutaminolysis function of GLS2 inhibits migration and invasion of HCC cells by repressing the epithelial-mesenchymal transition via the Dicer-miR-34a-Snail axis.
Collapse
Affiliation(s)
- Tsang-Chih Kuo
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan; Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chi-Kuan Chen
- Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan; Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Kuo-Tai Hua
- Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Pei Yu
- Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wei-Jiunn Lee
- Department of Urology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Min-Wei Chen
- Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yung-Ming Jeng
- Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Hsien Chien
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Kuang-Tai Kuo
- Division of Thoracic Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Division of Thoracic Surgery, Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Michael Hsiao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Min-Liang Kuo
- Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan; Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| |
Collapse
|
3
|
Amini-Bavil-Olyaee S, Alavian SM, Adeli A, Sarrami-Forooshani R, Sabahi F, Sabouri E, Tavangar HR, Azizi M, Mahboudi F. Hepatitis B virus genotyping, core promoter, and precore/core mutations among Afghan patients infected with hepatitis B: A preliminary report. J Med Virol 2006; 78:358-64. [PMID: 16419114 DOI: 10.1002/jmv.20547] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In spite of hepatitis B virus (HBV) vaccination, HBV infection remains an important public health problem worldwide. Although the HBV genotype distribution has been determined in some parts of South Central Asia, no survey has been conducted to determine the HBV genotype in Afghanistan. Twelve Afghan patients infected with HBV living in Afghanistan were enrolled in this study. Partial HBsAg and basic core promoter, precore, and core (BCP/preC/C) regions were amplified and subjected for direct sequencing. In parallel, precore G1896A mutation was also determined by an amplification-created restriction site method. Results revealed HBV genotype D (95% bootstrap value), sub-genotype D1 (98% bootstrap value), and subtype ayw2 in all Afghan isolates. Afghan isolates clustered in a separate branch in the D1 sub-genotype called D1', while supported by 82% bootstrap value. The percentage of intra-genotypic distance among Afghan isolates was 1.05% and inter-genotypic distance with the other genotype D was 2.87% and with other genotypes was 7.50%-11.1%. The wild-type, mixed infection, and precore mutant were found in six, two, and four HBV isolates, respectively. The A1762T/G1764A BCP dual mutation was found in one isolate. Three isolates presented single mutation in the BCP dual mutation region, whereas two showed a novel G1764T mutation. In conclusion, this preliminary study revealed HBV genotype D, sub-genotype D1, and subtype ayw2 of HBV among hepatitis B infected patients from Afghanistan. Further investigation should be carried out.
Collapse
|
6
|
Suk FM, Lin MH, Newman M, Pan S, Chen SH, Liu JD, Shih C. Replication advantage and host factor-independent phenotypes attributable to a common naturally occurring capsid mutation (I97L) in human hepatitis B virus. J Virol 2002; 76:12069-77. [PMID: 12414948 PMCID: PMC136898 DOI: 10.1128/jvi.76.23.12069-12077.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2002] [Accepted: 08/26/2002] [Indexed: 12/12/2022] Open
Abstract
Mutations of human hepatitis B virus (HBV) occur frequently within the capsid (core) protein in natural infections. The most frequent mutation of the core protein in HBV from Southeast Asia occurs at amino acid 97, changing an isoleucine (I) to a leucine (L). In our systematic study of virus-host interactions, we have examined the replication efficiency of a site-directed mutant, I97L, and its parental wild-type HBV in several different hepatoma cell lines. Interestingly, we found that this capsid variant replicated in human Huh7 hepatoma cells approximately 4.8-fold better than its parental wild-type HBV. A similar phenomenon was observed in another hepatoma cell line, J3. In addition, the level of encapsidated RNA pregenome in mutant I97L was about 5.7-fold higher than that of the wild-type HBV in Huh7 cells. Unlike Huh7 cells, no significant difference in viral DNA replication between the same I97L mutant and its parental wild-type HBV was observed in HepG2, a human hepatoblastoma cell line. This finding of a profound replication advantage for mutant I97L in Huh7 and J3 cells but not in HepG2 cells may have important implications for the emergence of this mutant in chronic HBV carriers. We speculate here that the mutation confers a host factor-independent growth advantage for the survival of HBV variants in gradually dedifferentiating hepatocytes and thus helps prolong viral persistence.
Collapse
Affiliation(s)
- Fat-Moon Suk
- Center for Tropical Diseases and Sealy Center for Vaccine Development, Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-0609, USA
| | | | | | | | | | | | | |
Collapse
|
7
|
Shamay M, Agami R, Shaul Y. HBV integrants of hepatocellular carcinoma cell lines contain an active enhancer. Oncogene 2001; 20:6811-9. [PMID: 11687960 DOI: 10.1038/sj.onc.1204879] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2001] [Revised: 07/17/2001] [Accepted: 08/01/2001] [Indexed: 12/14/2022]
Abstract
Hepatitis B virus (HBV) infection is a major risk factor worldwide for the development of hepatocellular carcinoma (HCC). Integrated HBV DNA fragments, often highly rearranged, are frequently detected in HCC. In woodchuck, the viral enhancer plays a central role in hepatocarcinogenesis, but in humans the mechanism of HBV oncogenesis has not been established. In this study we investigated the status of the viral enhancer in two human HCC cell lines, Hep3B and PLC/PRF/5 each containing one or more integrated HBV DNA fragments. Active enhancer was defined by virtue of its protein occupancy as determined by genomic in vivo DMS footprinting. In PLC/PRF/5 cells, the HBV DNA was integrated in a cellular gene at chromosome 11q13, at a locus reported to be amplified in many tumors. We show here that in both cell lines, the integrated HBV DNA fragments contain an active enhancer-I. In particular, the occupation of the two previously defined basic enhancer elements, E and EP, was prominent. While in both cell lines the same protein binds to the EP elements, the E element, however, is occupied in a cell-line specific manner. In PLC/PRF/5 but not Hep3B, the prominent binding of an undefined protein was detected. Our data suggest that this protein is likely to be the fetoprotein transcription factor (FTF). The finding that enhancer sequences are conserved and functional in different cell lines suggests a selection pressure for their long-term maintenance. We therefore propose that the HBV enhancer-I might play a role in hepatocellular carcinogenesis.
Collapse
Affiliation(s)
- M Shamay
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | | |
Collapse
|
8
|
Rabe C, Caselmann WH. Interaction of Hepatitis B virus with cellular processes in liver carcinogenesis. Crit Rev Clin Lab Sci 2000; 37:407-29. [PMID: 11078055 DOI: 10.1080/10408360091174277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatitis B infection is strongly linked epidemiologically to hepatocellular carcinoma development. This article reviews the molecular mechanisms by which hepatitis B encoded proteins such as hepatitis B x and hepatitis B surface transactivators may interact with gene transcription, tumor suppression, apoptosis, and signalling pathways of the liver cell with the possible consequence of tumor induction. Data on the interaction between hepatitis B proteins and cellular processes are often conflicting indicating a non-specific simultaneous interaction with antagonistic cellular processes that result in the formation of escape mutants that are not subject to these selective pressures.
Collapse
Affiliation(s)
- C Rabe
- Department of Medicine I, University of Bonn, Germany
| | | |
Collapse
|