Precise delivery of therapeutic cells to the desired site in vivo is an emerging and promising cellular therapy in precision medicine. This paper presents the development of a magnet‐driven and ...image‐guided degradable microrobot that can precisely deliver engineered stem cells for orthotopic liver tumor treatment. The microrobot employs a burr‐like porous sphere structure and is made with a synthesized composite to fulfill degradability, mechanical strength, and magnetic actuation capability simultaneously. The cells can be spontaneously released from the microrobots on the basis of the optimized microrobot structure. The microrobot is actuated by a gradient magnetic field and guided by a unique photoacoustic imaging technology. In preclinical experiments on nude mice, microrobots carrying cells are injected via the portal vein and the released cells from the microrobots can inhibit the tumor growth greatly. This paper reveals for the first time of using degradable microrobots for precise delivery of therapeutic cells in vascular tissue and demonstrates its therapeutic effect in preclinical test.
A magnet‐driven and image‐guided degradable microrobot is developed to achieve precise delivery of engineered stem cells in vivo. The microrobot meets the requirements of degradability, mechanical strength, and magnetic drive. Guided by photoacoustic imaging, microrobots successfully deliver cells to a targeted site for tumor treatment in mice. This study verifies the feasibility of magnetic microrobots in wireless and minimally invasive surgery.
Background and Aims
Most tumor cells use aerobic glycolysis (the Warburg effect) to support anabolic growth and promote tumorigenicity and drug resistance. Intriguingly, the molecular mechanisms ...underlying this phenomenon are not well understood. In this work, using gain‐of‐function and loss‐of‐function in vitro studies in patient‐derived organoid and cell cultures as well as in vivo positron emission tomography–magnetic resonance imaging animal models, we showed that protein arginine N‐methyltransferase 6 (PRMT6) regulates aerobic glycolysis in human hepatocellular carcinoma (HCC) through nuclear relocalization of pyruvate kinase M2 isoform (PKM2), a key regulator of the Warburg effect.
Approach and Results
We found PRMT6 to methylate CRAF at arginine 100, interfering with its RAS/RAF binding potential, and therefore altering extracellular signal–regulated kinase (ERK)‐mediated PKM2 translocation into the nucleus. This altered PRMT6‐ERK‐PKM2 signaling axis was further confirmed in both a HCC mouse model with endogenous knockout of PRMT6 as well as in HCC clinical samples. We also identified PRMT6 as a target of hypoxia through the transcriptional repressor element 1‐silencing transcription factor, linking PRMT6 with hypoxia in driving glycolytic events. Finally, we showed as a proof of concept the therapeutic potential of using 2‐deoxyglucose, a glycolysis inhibitor, to reverse tumorigenicity and sorafenib resistance mediated by PRMT6 deficiency in HCC.
Conclusions
Our findings indicate that the PRMT6‐ERK‐PKM2 regulatory axis is an important determinant of the Warburg effect in tumor cells, and provide a mechanistic link among tumorigenicity, sorafenib resistance, and glucose metabolism.
All hepatitis E virus (HEV) variants reported to infect humans belong to the species Orthohepevirus A (HEV-A). The zoonotic potential of the species Orthohepevirus C (HEV-C), which circulates in rats ...and is highly divergent from HEV-A, is unknown. We report a liver transplant recipient with hepatitis caused by HEV-C infection. We detected HEV-C RNA in multiple clinical samples and HEV-C antigen in the liver. The complete genome of the HEV-C isolate had 93.7% nt similarity to an HEV-C strain from Vietnam. The patient had preexisting HEV antibodies, which were not protective against HEV-C infection. Ribavirin was an effective treatment, resulting in resolution of hepatitis and clearance of HEV-C viremia. Testing for this zoonotic virus should be performed for immunocompromised and immunocompetent patients with unexplained hepatitis because routine hepatitis E diagnostic tests may miss HEV-C infection. HEV-C is also a potential threat to the blood product supply.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A novel theory in the field of tumor biology postulates that cancer growth is driven by a population of stem‐like cells, called tumor‐initiating cells (TICs). We previously identified a TIC ...population derived from hepatocellular carcinoma (HCC) that is characterized by membrane expression of CD133. Here, we describe a novel mechanism by which these cells mediate tumor growth and angiogenesis by systematic comparison of the gene expression profiles between sorted CD133 liver subpopulations through genome‐wide microarray analysis. A significantly dysregulated interleukin‐8 (IL‐8) signaling network was identified in CD133+ liver TICs obtained from HCC clinical samples and cell lines. IL‐8 was found to be overexpressed at both the genomic and proteomic levels in CD133+ cells isolated from HCC cell lines or clinical samples. Functional studies found enhanced IL‐8 secretion in CD133+ liver TICs to exhibit a greater ability to self‐renew, induce tumor angiogenesis, and initiate tumors. In further support of these observations, IL‐8 repression in CD133+ liver TICs by knockdown or neutralizing antibody abolished these effects. Subsequent studies of the IL‐8 functional network identified neurotensin (NTS) and CXCL1 to be preferentially expressed in CD133+ liver TICs. Addition of exogenous NTS resulted in concomitant up‐regulation of IL‐8 and CXCL1 with simultaneous activation of p‐ERK1/2 and RAF‐1, both key components of the mitogen‐activated protein kinase (MAPK) pathway. Enhanced IL‐8 secretion by CD133+ liver TICs can in turn activate an IL‐8‐dependent feedback loop that signals through the MAPK pathway. Further, in its role as a liver TIC marker CD133 also plays a functional part in regulating tumorigenesis of liver TICs by way of regulating NTS, IL‐8, CXCL1, and MAPK signaling. Conclusion: CD133+ liver TICs promote angiogenesis, tumorigenesis, and self‐renewal through NTS‐induced activation of the IL‐8 signaling cascade. (Hepatology 2012)
Plasmacytoid dendritic cells (pDCs) play immunosuppressive roles in the tumor microenvironment (TME). However, the molecular mechanisms underlying the recruitment and dysfunction of pDCs in the TME ...remain largely elusive, especially in hepatocellular carcinoma (HCC). In this study, we observed the accumulation of pDCs in the blood, tumor tissue, and ascitic fluid of HCC patients. A high density of tumor-infiltrating pDCs was correlated with poor prognosis in patients with HCC. Hypoxia-induced extracellular adenosine (eADO) significantly enhanced pDC recruitment into tumors via the adenosine A1 receptor (ADORA1). Mechanistically, hypoxia-inducible factor 1-alpha (HIF-1α) transcriptionally upregulated the expression of the ectonucleotidases CD39 and CD73 in HCC cells, both of which are essential for the generation of eADO. Moreover, eADO-stimulated pDCs promoted the induction of regulatory T cells and suppressed proliferation and cytotoxicity of CD8+ T cells. Depletion of pDCs using a monoclonal antibody or an ADORA1 antagonist significantly improved antitumor immunity and suppressed HCC growth in the immunocompetent HCC mouse model. Thus, targeting pDC recruitment may serve as a potential adjuvant strategy for immunotherapies in HCC.
•Tumor-derived extracellular adenosine (eADO) promoted pDC accumulation in HCC via adenosine A1 receptor.•HIF-1α upregulated the expression of ectonucleotidases CD39 andCD73, both of which are essential for the generation of eADO.•eADO-stimulated pDCs promoted the expansion of regulatory T cells and the exhaustion of CD8+ T cell.•Depletion of pDCs enhanced antitumor immunity and suppressed tumor growth.
Long‐term antiviral prophylaxis is required to prevent hepatitis B recurrence for patients with chronic hepatitis B after liver transplantation. We determined the long‐term outcome of 265 consecutive ...chronic hepatitis B liver transplant recipients treated with entecavir monotherapy without hepatitis B immune globulin. Viral serology, viral load, and liver biochemistry were performed at regular intervals during follow‐up. The median duration of follow‐up was 59 months. The cumulative rates of hepatitis B surface antigen (HBsAg) seroclearance were 90% and 95% at 1 and 5 years, respectively. At 1, 3, 5, and 8 years, 85%, 88%, 87.0%, and 92% were negative for HBsAg, respectively, and 95%, 99%, 100%, and 100% had undetectable hepatitis B virus (HBV) DNA, respectively. Fourteen patients remained persistently positive for HBsAg, all of whom had undetectable HBV DNA. There was no significant difference in liver stiffness for those who remained HBsAg‐positive compared to those who achieved HBsAg seroclearance (5.5 versus 5.2 kPa, respectively; P = 0.52). The overall 9‐year survival was 85%. There were 37 deaths during the follow‐up period, of which none were due to hepatitis B recurrence. Conclusion: Long‐term entecavir monotherapy is highly effective at preventing HBV reactivation after liver transplantation for chronic hepatitis B, with a durable HBsAg seroclearance rate of 92%, an undetectable HBV DNA rate of 100% at 8 years, and excellent long‐term survival of 85% at 9 years. (Hepatology 2017;66:1036‐1044).
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•ANXA3 confers HCC cells with the ability to resist sorafenib.•ANXA3 is enriched in sorafenib-resistant HCC.•ANXA3 activates autophagy and attenuates PKCδ/p38 dependent ...apoptosis.•ANXA3 is a useful predictive biomarker to stratify patients for sorafenib treatment.•Anti-ANXA3 therapy with sorafenib/regorafenib a potential treatment strategy for HCC.
Advanced hepatocellular carcinoma (HCC) is a lethal malignancy with limited treatment options. Sorafenib is the only FDA-approved first-line targeted drug for advanced HCC, but its effect on patient survival is limited. Further, patients ultimately present with disease progression. A better understanding of the causes of sorafenib resistance, enhancing the efficacy of sorafenib and finding a reliable predictive biomarker are crucial to achieve efficient control of HCC.
The functional effects of ANXA3 in conferring sorafenib resistance to HCC cells were analyzed in apoptotic and tumorigenicity assays. The role of ANXA3/PKCδ-mediated p38 signaling, and subsequently altered autophagic and apoptotic events, was assessed by immunoprecipitation, immunoblotting, immunofluorescence and transmission electron microscopy assays. The prognostic value of ANXA3 in predicting response to sorafenib was evaluated by immunohistochemistry. The therapeutic value of targeting ANXA3 to combat HCC with anti-ANXA3 monoclonal antibody alone or in combination with sorafenib/regorafenib was investigated ex vivo and in vivo.
ANXA3 conferred HCC cells with resistance to sorafenib. ANXA3 was found enriched in sorafenib-resistant HCC cells and patient-derived xenografts. Mechanistically, overexpression of ANXA3 in sorafenib-resistant HCC cells suppressed PKCδ/p38 associated apoptosis and activated autophagy for cell survival. Clinically, ANXA3 expression correlated positively with the autophagic marker LC3B in HCC and was associated with a worse overall survival in patients who went on to receive sorafenib treatment. Anti-ANXA3 monoclonal antibody therapy combined with sorafenib/regorafenib impaired tumor growth in vivo and significantly increased survival.
Anti-ANXA3 therapy in combination with sorafenib/regorafenib represents a novel therapeutic strategy for HCC treatment. ANXA3 represents a useful predictive biomarker to stratify patients with HCC for sorafenib treatment.
This study represents the most extensive pre-clinical characterization of anti-ANXA3 monoclonal antibodies for the treatment of hepatocellular carcinoma to date. These results support the clinical trial development of anti-ANXA3 antibodies in combination with sorafenib/regorafenib. Further studies will optimize patient target selection and identify the best treatment combinations.
Wnt/β‐catenin signaling is activated in CD133 liver cancer stem cells (CSCs), a subset of cells known to be a root of tumor recurrence and therapy resistance in hepatocellular carcinoma (HCC). ...However, the regulatory mechanism of this pathway in CSCs remains unclear. Here, we show that human microRNA (miRNA), miR‐1246, promotes cancer stemness, including self‐renewal, drug resistance, tumorigencity, and metastasis, by activation of the Wnt/β‐catenin pathway through suppressing the expression of AXIN2 and glycogen synthase kinase 3β (GSK3β), two key members of the β‐catenin destruction complex. Clinically, high endogenous and circulating miR‐1246 was identified in HCC clinical samples and correlated with a worse prognosis. Further functional analysis identified octamer 4 (Oct4) to be the direct upstream regulator of miR‐1246, which cooperatively drive β‐catenin activation in liver CSCs. Conclusion: These findings uncover the noncanonical regulation of Wnt/β‐catenin in liver CSCs by the Oct4/miR‐1246 signaling axis, and also provide a novel diagnostic marker as well as therapeutic intervention for HCC. (Hepatology 2016;64:2062‐2076).
Background and Aims
Embryonic stem‐cell–related transcription factors are central to the establishment and maintenance of stemness and pluripotency, and their altered expression plays key roles in ...tumors, including hepatocellular carcinoma (HCC), a malignancy with no effective treatment. Here, we report on the embryonic stem cell marker, reduced expression 1 (REX1; also known as zinc finger protein 42), to be selectively down‐regulated in HCC tumors.
Approach and Results
Deficiency of REX1 in HCC was attributed to a combination of hypermethylation at its promoter as well as histone modification by methylation and acetylation. Clinically, hypermethylation of REX1 was closely associated with neoplastic transition and advanced tumor stage in humans. Functionally, silencing of REX1 potentiated the tumor‐initiating and metastasis potential of HCC cell lines and xenografted tumors. Lentivirus‐mediated Rex1 ablation in liver of male immunocompetent mice with HCC, induced by hydrodynamic tail vein injection of proto‐oncogenes, enhanced HCC development. Transcriptome profiling studies revealed REX1 deficiency in HCC cells to be enriched with genes implicated in focal adhesion and mitogen‐activated protein kinase (MAPK) signaling. From this lead, we subsequently found REX1 to bind to the promoter region of mitogen‐activated protein kinase kinase 6 (MKK6), thereby obstructing its transcription, resulting in altered p38 MAPK signaling.
Conclusions
Our work describes a critical repressive function of REX1 in maintenance of HCC cells by regulating MKK6 binding and p38 MAPK signaling. REX1 deficiency induced enhancement of p38 MAPK signaling, leading to F‐actin reorganization and activation of nuclear factor erythroid 2‐related factor 2–mediated oxidative stress response, which collectively contributed to enhanced stemness and metastatic capabilities of HCC cells.
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