ObjectiveNon-alcoholic fatty liver disease (NAFLD) is a common prelude to cirrhosis and hepatocellular carcinoma. The genetic rs641738 C>T variant in the lysophosphatidylinositol acyltransferase 1 (LPIAT1)/membrane bound O-acyltransferase domain-containing 7, which incorporates arachidonic acid into phosphatidylinositol (PI), is associated with the entire spectrum of NAFLD. In this study, we investigated the mechanism underlying this association in mice and cultured human hepatocytes.DesignWe generated the hepatocyte-specific Lpiat1 knockout mice to investigate the function of Lpiat1 in vivo. We also depleted LPIAT1 in cultured human hepatic cells using CRISPR-Cas9 systems or siRNA. The effect of LPIAT1-depletion on liver fibrosis was examined in mice fed high fat diet and in liver spheroids. Lipid species were measured using liquid chromatography-electrospray ionisation mass spectrometry. Lipid metabolism was analysed using radiolabeled glycerol or fatty acids.ResultsThe hepatocyte-specific Lpiat1 knockout mice developed hepatic steatosis spontaneously, and hepatic fibrosis on high fat diet feeding. Depletion of LPIAT1 in cultured hepatic cells and in spheroids caused triglyceride accumulation and collagen deposition. The increase in hepatocyte fat content was due to a higher triglyceride synthesis fueled by a non-canonical pathway. Indeed, reduction in the PI acyl chain remodelling caused a high PI turnover, by stimulating at the same time PI synthesis and breakdown. The degradation of PI was mediated by a phospholipase C, which produces diacylglycerol, a precursor of triglyceride.ConclusionWe found a novel pathway fueling triglyceride synthesis in hepatocytes, by a direct metabolic flow of PI into triglycerides. Our findings provide an insight into the pathogenesis and therapeutics of NAFLD.

Objective: Signal transducer and activator of transcription 3 (STAT3) is activated in hepatocellular carcinoma (HCC), and tumor-associated macrophage plays an important role in tumor progression. Therefore, we examined STAT3 activation, cytokine expression and infiltration of tumor-associated macrophages in resected HCCs as well as the alteration of cell growth and migration by cytokine stimulation in HCC cell lines. Methods: Immunohistochemical staining of phosphorylated STAT3 (pSTAT3), CD163, interleukin (IL)-6, Ki-67 and Bcl-XL was performed for 101 cases of resected HCC, and correlations between pSTAT3 staining and clinicopathological findings were analyzed. In HCC cell lines (PLC/PRF/5 and Huh7), cell proliferation and migration by IL-6 stimulation and S3I-201 (STAT3 inhibitor) treatment were analyzed. Results: In HCC specimens, the pSTAT3-positive group showed high levels of α-fetoprotein (p = 0.0276), large tumor size (p = 0.0092), frequent intrahepatic metastasis (p = 0.0214), high Ki-67 (p = 0.0002) and Bcl-XL (p = 0.0001), poor prognosis (p = 0.0234), and high recurrence rate (p = 0.0003). CD163-positive cells were frequently observed in the pSTAT3-positive group (p = 0.0013). In two HCC cell lines, IL-6 stimulation promoted cell proliferation and migration via the STAT3 phosphorylation, and S3I-201 inhibited this activation. Conclusions: STAT3 activation was correlated with aggressive behavior of HCC and may be mediated via tumor-associated macrophage. We expect that STAT3 signaling and tumor-associated macrophages can be attractive therapeutic targets in HCC patients.

Critical to the function of mast cells in immune responses including allergy is their production of lipid mediators, among which only omega-6 (ω-6) arachidonate-derived eicosanoids have been well characterized. Here, by employing comprehensive lipidomics, we identify omega-3 (ω-3) fatty acid epoxides as new mast cell-derived lipid mediators and show that they are produced by PAF-AH2, an oxidized-phospholipid-selective phospholipase A2. Genetic or pharmacological deletion of PAF-AH2 reduced the steady-state production of ω-3 epoxides, leading to attenuated mast cell activation and anaphylaxis following FcɛRI cross-linking. Mechanistically, the ω-3 epoxides promote IgE-mediated activation of mast cells by downregulating Srcin1, a Src-inhibitory protein that counteracts FcɛRI signaling, through a pathway involving PPARg. Thus, the PAF-AH2-ω-3 epoxide-Srcin1 axis presents new potential drug targets for allergic diseases.

Biliary tract carcinoma develops within the intrahepatic or extrahepatic biliary tree and gallbladder. Primary sclerosing cholangitis, hepatolithiasis, congenital choledochal cyst, liver fluke infection, pancreatobiliary maljunction, toxic exposures and hepatitis virus infection are risk factors for the development of human biliary carcinoma. The precise molecular abnormalities of biliary carcinogenesis are still unknown, but chronic inflammatory conditions induce the production of reactive oxygen or nitrogen species leading to DNA damage. Recent studies indicate that cholangiocarcinoma of the large bile duct may arise in premalignant lesions such as biliary intraepithelial neoplasm (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB). BilIN and IPNB are generally confined to the large and septal-sized bile duct. BilINs are occasionally observed in non-biliary liver cirrhosis as well as chronic biliary disease. In contrast, the precursor lesion of intrahepatic cholangiocarcinoma of the small bile duct type remains unclear. We herein demonstrated the histological characteristics of different tumor development pathways from premalignant lesion to carcinoma in different sites of the biliary tree.

Background: We aimed to investigate the e cacy and safety of atezolizumab plus bevacizumab therapy in patients with unresectable hepatocellular carcinoma (u-HCC) based on whether they had previously received systemic therapy, as well as the association of atezolizumab plus bevacizumab with early alphafetoprotein (AFP) response in real-world practice.Methods: A total of 52 patients with u-HCC were treated with atezolizumab plus bevacizumab between October 2020 and April 2021. The Response Evaluation Criteria in Solid Tumors (RECIST) and modi ed RECIST were used to evaluate radiological responses.Results: The patients received atezolizumab plus bevacizumab as 1st-line (n = 23), 2nd-line (n = 16), 3rdline (n = 6), 4th-line (n = 3), 5th-line (n = 3), or 6th-line (n = 1) therapy. The objective response rate and disease control rate in all patients were 18.4% and 63.2%, respectively. Sixteen patients experienced no adverse events (AEs), whereas 4 patients discontinued therapy due to AEs. The median time to progression (TTP) was signi cantly longer among patients receiving atezolizumab plus bevacizumab as 1st-line therapy than in patients receiving atezolizumab plus bevacizumab as later-line therapy (P = 0.02).Patients with an AFP response (reduction ≥20% from baseline) at 6 weeks had a signi cantly longer TTP than those without an AFP response (P = 0.02). Conclusion:Patients who received atezolizumab plus bevacizumab as 1st-line therapy had better clinical outcome than those who received atezolizumab plus bevacizumab in later lines. The AFP response at 6 weeks could be a predictor of disease progression.

Glucose transporter (GLUT)-1 is expressed in malignant tumors and correlated with poor outcome in several cancers. Biliary intraepithelial neoplasia (BilIN) is considered to be a precursor or a noninvasive lesion of invasive cholangiocarcinoma. We examined GLUT-1 and GLUT-2 expression in 149 intrahepatic cholangiocarcinomas and 39 BilINs immunohistochemically and evaluated their correlation with clinicopathological findings and patient outcome in intrahepatic cholangiocarcinoma. Furthermore, we examined the role of GLUT-1 on migration and invasion of cholangiocarcinoma cells using GLUT-1 siRNA. In intrahepatic cholangiocarcinoma, GLUT-1 expression was frequently observed near the necrotic areas, whereas GLUT-2 expression tended to be observed in adenocarcinoma of large bile ducts. Compared with the GLUT-1-negative group, the GLUT-1-positive group showed significantly larger tumor size (P = .0031), poor differentiation (P < .0001), frequent lymphatic invasion (P = .0031) and lymph node metastasis (P < .0001), and high HIF-1α expression (P = .0297). GLUT-2 expression was significantly correlated with good differentiation (P = .0015), perihilar location (P < .0001), perineural invasion (P = .0049), and lymph node metastasis (P = .0248). The patients with GLUT-1-positive tumors showed poor disease related survival (P < .0001). The numbers of migrating and invading cells were significantly decreased in GLUT-1 siRNA transfectants of cholangiocarcinoma cells. Although, GLUT-1 was expressed in all grades of BilINs, GLUT-2 was expressed only in high-grade BilINs. Our results suggest that GLUT-1 expression correlates aggressive behavior and poor prognosis, and that GLUT-1 might be a therapeutic target of cholangiocarcinoma. GLUT-2 expression may be associated with cholangiocarcinogenesis of large bile duct and is a helpful marker for detecting high-grade BilIN lesions in atypical bile ducts.

Our study indicates that FDG uptake is associated with the expression of pSTAT3, HIF1α, and GLUT1 in hepatocellular carcinoma. The expression of these proteins shows a correlation with poor differentiation and vascular invasion.

Spalt-like transcriptional factor 4 (SALL4), a stem marker, is reactivated in several cancers. A previous study has demonstrated that SALL4 interacts with the nucleosome remodeling deacetylase complex, which contains histone deacetylase 1 (HDAC1) and histone deacetylase 2 (HDAC2). In this study, we investigated the expression status of SALL4, HDAC1, and HDAC2 and their relationship with phosphatase and tensin homolog deleted on chromosome 10 (PTEN) by immunohistochemical analysis of the posthepatectomy specimens of 135 patients with hepatocellular carcinoma who were treated at our hospital. Ninety-two frozen samples were subjected to quantitative reverse-transcription polymerase chain reaction analysis to detect the messenger RNA levels of PTEN. Seventy-six (56%) of 135 patients were positive for SALL4, and this group had a higher prevalence of hepatitis B antigen, a higher value of α-fetoprotein (AFP) and protein induced by vitamin K absence (PIVKAII) and poor histologic differentiation. The 5-year survival rate was significantly lower in the SALL4-positive group. High HDAC1 expression (51%) was correlated with a poor histologic differentiation and a poor prognosis. High HDAC2 expression (46%) was associated with a higher prevalence of hepatitis B antigen positivity, a poor histologic differentiation and higher prevalence of vascular invasion, and a lower 5-year survival rate. Coexpression of SALL4 with HDAC1 and/or HDAC2 was correlated with underexpression of PTEN. Moreover, multivariable analysis revealed that coexpression of SALL4 with HDAC1 and/or HDAC2 was predictive of an unfavorable prognosis. Our data thus suggested that the combination of SALL4, HDAC1, and HDAC2 may provide a potential target for molecular therapy.