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1.
J Biol Chem ; 300(3): 105742, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38346537

ABSTRACT

Human satellite II (HSATII), composed of tandem repeats in pericentromeric regions, is aberrantly transcribed in epithelial cancers, particularly pancreatic cancer. Dysregulation of repetitive elements in cancer tissues can facilitate incidental dsRNA formation; however, it remains controversial whether dsRNAs play tumor-promoting or tumor-suppressing roles during cancer progression. Therefore, we focused on the double-stranded formation of HSATII RNA and explored its molecular function. The overexpression of double-stranded HSATII (dsHSATII) RNA promoted mesenchymal-like morphological changes and enhanced the invasiveness of pancreatic cancer cells. We identified an RNA-binding protein, spermatid perinuclear RNA-binding protein (STRBP), which preferentially binds to dsHSATII RNA rather than single-stranded HSATII RNA. The mesenchymal transition of dsHSATII-expressing cells was rescued by STRBP overexpression. Mechanistically, STRBP is involved in the alternative splicing of genes associated with epithelial-mesenchymal transition (EMT). We also confirmed that isoform switching of CLSTN1, driven by dsHSATII overexpression or STRBP depletion, induced EMT-like morphological changes. These findings reveal a novel tumor-promoting function of dsHSATII RNA, inducing EMT-like changes and cell invasiveness, thus enhancing our understanding of the biological significance of aberrant expression of satellite arrays in malignant tumors.


Subject(s)
Alternative Splicing , DNA, Satellite , Epithelial-Mesenchymal Transition , Gene Expression Regulation, Neoplastic , Pancreatic Neoplasms , RNA, Double-Stranded , Humans , Alternative Splicing/genetics , Cell Line, Tumor , Epithelial-Mesenchymal Transition/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , RNA, Double-Stranded/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Microtubule-Associated Proteins/deficiency , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Calcium-Binding Proteins/chemistry , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Disease Progression , Neoplasm Invasiveness/genetics , DNA, Satellite/genetics
2.
Hepatol Commun ; 7(11)2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37938099

ABSTRACT

BACKGROUND: Precision medicine and customized therapeutics based on the features of each patient are important for maximizing therapeutic effects. Because most cases of HCC occur in the damaged liver through various etiologies, such as hepatitis virus infection, steatohepatitis, and autoimmune hepatitis, there should be a rationale for the choice of therapeutic options based on these etiologies. Although cabozantinib, an oral multikinase inhibitor, has demonstrated clinical effectiveness in advanced HCC, subgroup analyses showed a lower HR for death in HBV-related HCC. This study aimed to determine the therapeutic effects of cabozantinib in HBV-related HCC. METHODS: Using HBV infection models and gene knockout cells, we determined the crucial signaling axis responsible for the effects of cabozantinib on HBV. A chromatin immunoprecipitation assay was performed to determine the interaction between the signaling molecules and HBV DNA. Agonists and inhibitors were used for confirmation. RESULTS: Cabozantinib inhibited HBV replication through the HGF-mesenchymal-epithelial transition factor-signal transducer and activator of transcription 3 (MET-STAT3) signaling axis. The importance of STAT3 in viral replication has been confirmed using gene-edited STAT3 knockout cells. The chromatin immunoprecipitation assay revealed that the binding levels of phosphorylated STAT3 to enhancer region 1 of HBV covalently closed circular DNA were significantly increased by HGF stimulation. CONCLUSIONS: Cabozantinib has favorable therapeutic effects on HBV-related HCC because it inhibits HCC not only directly but also indirectly by means of inhibitory effects on HBV.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Hepatitis B virus/genetics , STAT3 Transcription Factor/genetics , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/drug therapy
3.
Biochem Biophys Res Commun ; 607: 89-95, 2022 06 04.
Article in English | MEDLINE | ID: mdl-35367833

ABSTRACT

DNA repair processes represent attractive synthetic lethal targets because many cancers exhibit impaired DNA repair pathways, which leads to dependence on specific repair proteins. The finding that poly (ADP-ribose) polymerase (PARP)-1 inhibitors are highly effective against cancers with deficient homologous recombination highlights the potential of this approach. In hepatitis B viral (HBV) infection, degradation of the structural maintenance of the chromosome 5/6 (Smc5/6) complex, which plays a key role in repairing double-stranded DNA breaks by homologous recombination, is induced by HBV regulatory protein X (HBx). Here, we hypothesized that a deficiency in the Smc5/6 complex in HBV-associated hepatocellular carcinoma (HCC) increases susceptibility to PARP inhibitors via a deficiency in homologous recombination. We confirmed impaired double-stranded DNA break repair in HBx-expressing HCC cells using a sensitive reporter to monitor homologous recombination. Treatment with a PARP inhibitor was significantly more effective against HBx-expressing HCC cells, and overexpression of Smc5/6 prevented these effects. Overall, our results suggest that homologous recombination deficiency in HBV-associated HCC leads to increased susceptibility to PARP inhibitors.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Carcinoma, Hepatocellular/drug therapy , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/genetics , Hepatitis B virus/genetics , Hepatitis B virus/metabolism , Homologous Recombination , Humans , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerases/genetics
4.
J Hepatol ; 76(1): 53-62, 2022 01.
Article in English | MEDLINE | ID: mdl-34478763

ABSTRACT

BACKGROUND & AIMS: HBV causes hepatocellular carcinoma (HCC). While it was recently shown that the ability of HBV X protein (HBx) to impair the Smc5/6 (structural maintenance of chromosome 5/6) complex is important for viral transcription, HBx is also a potent driver of HCC. However, the mechanism by which HBx expression induces hepatocarcinogenesis is unclear. METHODS: Degradation of the Smc5/6 complex and accumulation of DNA damage were observed in both in vivo and in vitro HBV infection models. Rescue experiments were performed using nitazoxanide (NTZ), which inhibits degradation of the Smc5/6 complex by HBx. RESULTS: HBx-triggered degradation of the Smc5/6 complex causes impaired homologous recombination (HR) repair of DNA double-strand breaks (DSBs), leading to cellular transformation. We found that DNA damage accumulated in the liver tissue of HBV-infected humanized chimeric mice, HBx-transgenic mice, and human tissues. HBx suppressed the HR repair of DSBs, including that induced by the CRISPR-Cas9 system, in an Smc5/6-dependent manner, which was rescued by restoring the Smc5/6 complex. NTZ restored HR repair in, and colony formation by, HBx-expressing cells. CONCLUSIONS: Degradation of the Smc5/6 complex by HBx increases viral transcription and promotes cellular transformation by impairing HR repair of DSBs. LAY SUMMARY: The hepatitis B virus expresses a regulatory protein called HBV X protein (or HBx). This protein degrades the Smc5/6 complex in human hepatocytes, which is essential for viral replication. We found that this process also plays a key role in the accumulation of DNA damage, which contributes to HBx-mediated tumorigenesis.


Subject(s)
Cell Cycle Proteins/adverse effects , Chromosomal Proteins, Non-Histone/adverse effects , Recombinational DNA Repair/drug effects , Trans-Activators/drug effects , Viral Regulatory and Accessory Proteins/drug effects , Animals , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/pathology , Disease Models, Animal , Liver/drug effects , Liver/pathology , Liver Neoplasms/complications , Liver Neoplasms/pathology , Mice , Recombinational DNA Repair/immunology , Statistics, Nonparametric
5.
Heliyon ; 7(7): e07586, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34345745

ABSTRACT

Although nucleos(t)ide analogs and interferons suppress hepatitis B virus (HBV) replication, they must be taken continuously and have a low response rate. Therefore, therapeutics for HBV with novel modes of action are needed. Humanized virus-suppressing factor (hzVSF) is a monoclonal antibody against vimentin that exhibits broad-spectrum antiviral activity. Here, hzVSF significantly inhibited HBV infection. Although hzVSF inhibited HBV RNA production, it did not affect viral transcription from minicircle DNA mimicking covalently closed circular DNA. Additionally, hzVSF did not inhibit viral protein or DNA release from infected cells. Rather, hzVSF inhibited the cell entry of viral preS1 peptides, possibly by altering intracellular vimentin localization, which is important for HBV cell entry. These results suggest that hzVSF has therapeutic potential for HBV infection with a novel mode of action.

6.
BMC Gastroenterol ; 21(1): 16, 2021 Jan 06.
Article in English | MEDLINE | ID: mdl-33407172

ABSTRACT

BACKGROUND: Impairment of activities of daily living (ADL) due to hemorrhagic gastroduodenal ulcers (HGU) has rarely been evaluated. We analyzed the risk factors of poor prognosis, including mortality and impairment of ADL, in patients with HGU. METHODS: In total, 582 patients diagnosed with HGU were retrospectively analyzed. Admission to a care facility or the need for home adaptations during hospitalization were defined as ADL decline. The clinical factors were evaluated: endoscopic features, need for interventional endoscopic procedures, comorbidities, symptoms, and medications. The risk factors of outcomes were examined with multivariate analysis. RESULTS: Advanced age (> 75 years) was a significant predictor of poor prognosis, including impairment of ADL. Additional significant risk factors were renal disease (odds ratio [OR] 3.43; 95% confidence interval [CI] 1.44-8.14) for overall mortality, proton pump inhibitor (PPIs) usage prior to hemorrhage (OR 5.80; 95% CI 2.08-16.2), and heart disease (OR 3.05; 95% CI 1.11-8.43) for the impairment of ADL. Analysis of elderly (> 75 years) subjects alone also revealed that use of PPIs prior to hemorrhage was a significant predictor for the impairment of ADL (OR 8.24; 95% CI 2.36-28.7). CONCLUSION: In addition to advanced age, the presence of comorbidities was a risk of poor outcomes in patients with HGU. PPI use prior to hemorrhage was a significant risk factor for the impairment of ADL, both in overall HGU patients and in elderly patients alone. These findings suggest that the current strategy for PPI use needs reconsideration.


Subject(s)
Activities of Daily Living , Peptic Ulcer , Aged , Hemorrhage , Humans , Peptic Ulcer/complications , Peptic Ulcer/epidemiology , Prognosis , Retrospective Studies , Risk Factors
7.
Clin J Gastroenterol ; 14(1): 314-318, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32779145

ABSTRACT

Intraductal papillary mucinous neoplasm of the bile duct (IPNB) is an epithelial tumor that can cause obstructive jaundice and cholangitis due to mucin production. Although the effectiveness of argon plasma coagulation in IPNB treatment has been demonstrated, the long-term effect of the therapy is largely unknown. Here, we have presented a patient with IPNB who underwent argon plasma coagulation with a follow-up period of more than 2 years. A 74-year-old woman was referred to our department for treatment of obstructive jaundice. Endoscopic retrograde cholangiopancreatography revealed marked dilation of intrahepatic and extrahepatic bile ducts and thick mucin drainage from the ampulla of Vater. IPNB was diagnosed pathologically from biopsy specimens. Surgery was not recommended because of the extensive intrahepatic spread of the lesion. Endoscopic sphincterotomy, endoscopic papillary large balloon dilation, and insertion of a metallic stent could not resolve the obstructive jaundice. Finally, argon plasma coagulation with percutaneous cholangioscopy was performed 3 times over 1 month. After treatment, obstructive jaundice was resolved and the patient's clinical condition has been stable for more than 2 years, except for a single episode of transient cholangitis. In conclusion, argon plasma coagulation may be an alternative to surgery for the palliation of jaundice with IPNB.


Subject(s)
Bile Duct Neoplasms , Pancreatic Neoplasms , Aged , Argon Plasma Coagulation , Bile Duct Neoplasms/complications , Bile Duct Neoplasms/surgery , Bile Ducts , Bile Ducts, Intrahepatic , Female , Humans
9.
Sci Rep ; 10(1): 15556, 2020 09 23.
Article in English | MEDLINE | ID: mdl-32968163

ABSTRACT

MICA/B proteins are expressed on the surface of various types of stressed cells, including cancer cells. Cytotoxic lymphocytes expressing natural killer group 2D (NKG2D) receptor recognize MICA/B and eliminate the cells. However, cancer cells evade such immune recognition by inducing proteolytic shedding of MICA/B proteins. Therefore, preventing the shedding of MICA/B proteins could enhance antitumor immunity. Here, by screening a protease inhibitor library, we found that the fatty-acid amide hydrolase (FAAH) inhibitor, URB597, suppresses the shedding of MICA/B. URB597 significantly reduced the soluble MICA level in culture medium and increased the MICA level on the surface of cancer cells. The effect was indirect, being mediated by increased expression of tissue inhibitor of metalloproteinases 3 (TIMP3). Knockdown of TIMP3 expression reversed the effect of URB597, confirming that TIMP3 is required for the MICA shedding inhibition by URB597. In contrast, FAAH overexpression reduced TIMP3 expression and the cell-surface MICA level and increased the soluble MICA level. These results suggest that inhibition of FAAH could prevent human cancer cell evasion of immune-mediated clearance.


Subject(s)
Amidohydrolases/genetics , Histocompatibility Antigens Class I/genetics , Tissue Inhibitor of Metalloproteinase-3/genetics , Benzamides/chemistry , Benzamides/pharmacology , Carbamates/chemistry , Carbamates/pharmacology , Cell Line, Tumor , Culture Media/chemistry , Culture Media/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Histocompatibility Antigens Class I/drug effects , Humans , NK Cell Lectin-Like Receptor Subfamily K/genetics , NK Cell Lectin-Like Receptor Subfamily K/immunology , Neoplasms/drug therapy , Neoplasms/genetics , T-Lymphocytes, Cytotoxic/drug effects , T-Lymphocytes, Cytotoxic/immunology
10.
Gut Liver ; 14(6): 842-849, 2020 11 15.
Article in English | MEDLINE | ID: mdl-32050314

ABSTRACT

Background/Aims: Empiric antibiotics are given in combination with biliary drainage for acute cholangitis but sometimes turn out to be insensitive to microorganisms in blood and bile. Clinical outcomes were compared according to sensitivity to microorganisms detected in blood and bile culture to evaluate the impact of sensitivity to empiric antibiotics in cholangitis. Methods: Consecutive patients who underwent biliary drainage for acute cholangitis were retrospectively studied. Clinical outcomes such as 30-day mortality, length of hospital stay and high care unit stay, organ dysfunction and duration of fever were compared in three groups: group A (sensitive to both blood and bile culture), group B (sensitive to blood culture alone) and group C (insensitive to both blood and bile culture). Results: Eighty episodes of cholangitis were classified according to sensitivity results: 42, 32 and six in groups A, B and C. Escherichia coli and Klebsiella were two major pathogens. There were no significant differences in 30-day mortality rate (7%, 0%, and 0%, p=0.244), length of hospital stay (28.5, 21.0, and 20.5 days, p=0.369), organ dysfunction rate (14%, 25%, and 17%, p=0.500), duration of fever (4.3, 3.2, and 3.5 days, p=0.921) and length of high care unit stay (1.4, 1.2, and 1.7 days, p=0.070) in groups A, B and C. Empiric antibiotics were changed in 11 episodes but clinical outcomes appeared to be non-inferior even in 31 episodes of cholangitis who were on inadequate antibiotics throughout the course. Conclusions: Sensitivity of empiric antibiotics was not associated with clinical outcomes in acute cholangitis.


Subject(s)
Cholangitis , Acute Disease , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Cholangiopancreatography, Endoscopic Retrograde , Cholangitis/therapy , Drainage , Female , Humans , Male , Retrospective Studies
11.
Oncol Rep ; 42(4): 1459-1466, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31322270

ABSTRACT

The expression of CDR1­AS, a representative circular RNA, is closely linked with poor prognosis in gastrointestinal cancers, such as colon, liver, and pancreatic cancers. Although it is well known that CDR1­AS antagonizes microRNA­7 function through its sequence similarities in the brain, its biological function and link with the malignant potential of cancer cells remain unclear, partly due to the difficulties of ectopic expression of circular RNAs. In the present study, SW620, a colon cancer cell line that stably expresses CDR1­AS RNA circularized, was established using the laccase 2 gene cassette, and its biological function associated with malignant behavior was determined. In contrast to previous studies, cell growth or invasion ability was not altered by CDR1­AS expression. However, the expression levels of CMTM4 and CMTM6, which were recently recognized as critical regulators of PD­L1 protein expression at the cell surface, were significantly increased. Accordingly, the cell surface PD­L1 protein levels were increased in CDR1­AS­expressing cells. Notably, the effects were not canceled out by overexpressing microRNA­7, indicating that the increase in cell surface PD­L1 in CDR1­AS­expressing cells was not dependent on microRNA­7 function. These results indicated that expression of this circular RNA in cancer cells may lead to poor prognosis by increasing cell surface PD­L1 levels through microRNA­7­independent mechanisms.


Subject(s)
B7-H1 Antigen/biosynthesis , Colorectal Neoplasms/metabolism , RNA, Long Noncoding/biosynthesis , Animals , B7-H1 Antigen/genetics , Caco-2 Cells , Cell Growth Processes/physiology , Cell Line, Tumor , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , HEK293 Cells , Humans , Immunohistochemistry , MARVEL Domain-Containing Proteins/biosynthesis , MARVEL Domain-Containing Proteins/genetics , Male , Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/antagonists & inhibitors , MicroRNAs/genetics , MicroRNAs/metabolism , Myelin Proteins , Neoplasm Invasiveness , Prognosis , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism
12.
Hepatology ; 69(5): 1903-1915, 2019 05.
Article in English | MEDLINE | ID: mdl-30586159

ABSTRACT

Hepatitis B virus (HBV) infection is a major health concern worldwide. To prevent HBV-related mortality, elimination of viral proteins is considered the ultimate goal of HBV treatment; however, currently available nucleos(t)ide analogs rarely achieve this goal, as viral transcription from episomal viral covalently closed circular DNA (cccDNA) is not prevented. HBV regulatory protein X was recently found to target the protein structural maintenance of chromosomes 5/6 (Smc5/6) for ubiquitination and degradation by DDB1-CUL4-ROC1 E3 ligase, resulting in enhanced viral transcription from cccDNA. This ubiquitin-dependent proteasomal pathway requires an additional ubiquitin-like protein for activation, neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8). Here, we show that pevonedistat, a NEDD8-activating enzyme inhibitor, works efficiently as an antiviral agent. Pevonedistat significantly restored Smc5/6 protein levels and suppressed viral transcription and protein production in the HBV minicircle system in in vitro HBV replication models and in human primary hepatocytes infected naturally with HBV. Conclusion: These results indicate that pevonedistat is a promising compound to treat chronic HBV infection.


Subject(s)
Cyclopentanes/pharmacology , Hepatitis B virus/drug effects , Pyrimidines/pharmacology , Ubiquitin-Activating Enzymes/antagonists & inhibitors , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Cyclopentanes/therapeutic use , Drug Evaluation, Preclinical , HEK293 Cells , Hep G2 Cells , Hepatitis B/drug therapy , Humans , Primary Cell Culture , Pyrimidines/therapeutic use , Ubiquitin-Protein Ligases/metabolism , Virus Replication/drug effects
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