Real-world experience of postoperative adjuvant chemoimmunotherapy in patients with perihilar cholangiocarcinoma at high risk of recurrence.

BACKGROUND: This study aimed to assess whether postoperative adjuvant chemoimmunotherapy could lead to better clinical outcomes for high-risk patients with perihilar cholangiocarcinoma (pCCA). METHODS: In the cohort study, we retrospectively reviewed patients who received surgical resection for pCCA with curative intent from January 2018 to December 2021 at the Sun Yat-sen Memorial Hospital. The patients at high risk for relapse were further analyzed. Among them, 20 patients received adjuvant chemoimmunotherapy, 28 patients received adjuvant chemotherapy, and 33 patients received surgery alone. The oncological outcomes and drug-associated adverse events were evaluated. RESULTS: The 2-year overall survival (OS) rates in patients treated with adjuvant chemoimmunotherapy, adjuvant chemotherapy, and surgery alone were 80.0%, 49.4% and 22.6%, respectively. Univariable and multivariable Cox analyses showed that the treatment regimen and TNM stage were associated with adverse OS. Adjuvant chemoimmunotherapy led to an increase in OS compared with adjuvant chemotherapy [hazard ratio (HR) = 3.253; 95% confidence interval (CI) 1.072-9.870; P = 0.037] or surgery alone (HR = 7.560; 95% CI 2.508-22.785; P < 0.001). The median recurrence-free survival was 22.0 months for the adjuvant chemoimmunotherapy group, 17.0 months for the adjuvant chemotherapy group, and 13.2 months for the surgery alone group (P = 0.177); these differences were not significant. The chemoimmunotherapy group was associated with more frequent hematological side effects than the chemotherapy group, but the difference was not statistically significant. CONCLUSION: Postoperative adjuvant chemoimmunotherapy for resected pCCA patients showed improved OS compared with adjuvant chemotherapy or surgery alone, and further prospectively randomized controlled trials are necessary to validate these results.

Hepatitis B Virus Surface Antigen Promotes Stemness of Hepatocellular Carcinoma through Regulating MicroRNA-203a.

Background and Aims: Patients with persistent positive hepatitis B surface antigen (HBsAg), even with a low HBV-DNA load, have a higher risk of hepatocellular carcinoma (HCC) than those without HBV infection. Given that tumor stemness has a critical role in the occurrence and maintenance of neoplasms, this study aimed to explore whether HBsAg affects biological function and stemness of HCC by regulating microRNA, and to explore underlying mechanisms. Methods: We screened out miR-203a, the most significant down-regulated microRNA in the microarray analysis of HBsAg-positive samples and focused on that miRNA in the ensuing study. In vitro and in vivo functional experiments were performed to assess its regulatory function. The effect of miR-203a on stemness and the possible correlation with BMI1 were analyzed in this study. Results: MiR-203a was significantly down-regulated in HBsAg-positive HCC with the sharpest decrease shown in microarray analysis. The negative correlation between miR-203a and HBsAg expression was confirmed by quantitative real-time PCR after stimulation or overexpression/knockdown of HBsAg in cells. We demonstrated the function of miR-203a in inhibiting HCC cell proliferation, migration, clonogenic capacity, and tumor development in vivo. Furthermore, the overexpression of miR-203a remarkably increases the sensitivity of tumor cells to 5-FU treatment and decreases the proportion of HCC cells with stem markers. In concordance with our study, the survival analysis of both The Cancer Genome Atlas database and samples in our center indicated a worse prognosis in patients with low level of miR-203a. We also found that BMI1, a gene maintains the self-renewal capacity of stem cells, showed a significant negative correlation with miR-203a in HCC specimen (p<0.001). Similarly, opposite BMI1 changes after overexpression/knockdown of miR-203a were also confirmed in vitro. Dual luciferase reporting assay suggested that miR-203a may regulate BMI1 expression by direct binding. Conclusions: HBsAg may promote the development of HCC and tumor stemness by inhibiting miR-203a, resulting in poor prognosis. miR-203a may serve as a crucial treatment target in HBsAg-positive HCC. More explicit mechanistic studies and animal experiments need to be conducted as a next step.

Complete Response to Combined Chemotherapy and Anti-PD-1 Therapy for Recurrent Gallbladder Carcinosarcoma: A Case Report and Literature Review.

Background: Gallbladder carcinosarcoma (GBCS) is a rare and aggressive malignancy with extremely poor prognosis. Although surgery is regarded as the primary therapy for GBCS, the effective therapeutic strategies for unresected lesions have been poorly defined. Case Presentation: We presented a case of a 74-year-old male who underwent radical resection of gallbladder carcinoma at a local hospital. Seven months later, he was admitted to our hospital due to right upper abdominal discomfort. Postoperative radiological examinations showed multiple hepatic lesions, hilar lymph node metastasis, and main portal vein tumor thrombus. The pathological consultation results confirmed GBCS and immunohistochemical examinations revealed PD-L1 expression in 20% of tumor cells. Then, the patient received chemotherapy (Gemcitabine plus Oxaliplatin, GEMOX) in combination with anti-PD-1 therapy. After nine courses of the combination therapy, complete regression of the tumors was achieved with no evidence of relapse till now. Conclusions: We, for the first time, reported a patient with recurrent GBCS who benefited from the combined chemotherapy and immunotherapy, providing a potential effective management strategy for the refractory malignant tumor.

Immune Checkpoint FGL1 Expression of Circulating Tumor Cells Is Associated With Poor Survival in Curatively Resected Hepatocellular Carcinoma.

LAG-3 is one of the common tumor immune checkpoints. LAG-3 can inhibit the activation and proliferation of T cells, and can also suppress immunity by regulating other immune-related cell functions. FGL1 was recently discovered to be the main ligand of immune checkpoint LAG-3 and play a critical role in the inhibition of T cells. However, the FGL1 expression in circulating tumor cells (CTCs) and its clinical significance in hepatocellular carcinoma (HCC) remain unclear. Therefore, this bioinformatics analysis was performed to assess the expression of FGL1 in various tumors and its association with immune infiltration. After that, CTCs from 109 HCC patients were detected and the immunofluorescence staining was performed (CD45, EpCAM, CK8/18/19, Vimentin, Twist, DAPI and FGL1). Then, we investigated FGL1 expression and EMT of CTCs and analyzed its relationship with patient survival and clinical relevance. Bioinformatic results showed that FGL1 expression was abnormal in various tumor and it was correlated with the infiltration level of several immune cells. FGL1 expression was detected in CTCs of 40 patients (36.7%). The proportion of advanced TNM stage (P<0.001) and distant metastasis(P=0.020) in FGL1 positive patients was higher than that of FGL1 negative patients. In addition, patients with FGL1 positive circulating tumor cells had worse postoperative survival than FGL1 negative patients (p=0.0297). The mixed phenotypic CTC presented a higher level of FGL1 expression than any other types, the number of which also predicted worse prognosis(p=0.0443). We also found that the expression of FGL1 on CTCs was associated with the level of FGL1 in tumor tissues. Of 12 patients receiving PD-1/PD-L1 blockade in a total of 109 cases, 8 out of 10 patients with FGL1 positive CTC showed immunotherapy resistance. It is the first study that suggested FGL1 expression in CTCs as an indicator of the poor prognosis in HCC patients. CTC detection may serve as a promising replacement for determination of tumor tissue FGL1 expression and provide evidence for the application of immunotherapy.

Anti-programmed cell death ligand 1-based immunotherapy in recurrent hepatocellular carcinoma with inferior vena cava tumor thrombus and metastasis: Three case reports.

BACKGROUND: Recurrent hepatocellular carcinoma (HCC) with inferior vena cava tumor thrombus is a great challenge for oncologists and has a poor prognosis. To date, the safety and efficacy of programmed cell death ligand 1 (PD-L1) inhibitors are still unknown. CASE SUMMARY: A 59-year-old male was identified as having a tumor thrombus in the inferior vena cava 3 years after surgery. The patient underwent a second surgery and adjuvant chemotherapy. However, the level of alpha-fetoprotein was elevated after 2 mo, and lung metastases and mediastinal lymph node metastases were identified. The expression of PD-L1 in HCC and inferior vena cava tumor thrombus tissues was analyzed by immunohistochemistry. Then, the patient received atezolizumab immunotherapy. The level of alpha-fetoprotein dropped to normal, the mediastinal lymph node metastases decreased in size and the lung metastases disappeared after 3 mo of immunotherapy. The patient had no signs of recurrence at 21 mo of follow-up. A 60-year-old male underwent left hepatic tumor resection, inferior vena cava incision and thrombus removal, followed by regular chemotherapy. The patient developed lung and splenic metastases after surgery. Pembrolizumab was used for six courses, and the splenic metastasis shrank, after which splenectomy was performed. The patient continued to receive pembrolizumab for thirteen courses, and the lung metastases showed no progression. A 34-year-old male was diagnosed with liver cancer with inferior vena cava tumor thrombus. The patient underwent right hepatectomy and received tislelizumab for three courses. He is still receiving immunotherapy and in good condition. CONCLUSION: Anti-PD-L1 therapy in HCC patients with inferior vena cava tumor thrombus and metastasis is associated with relatively good patient outcomes.

Screening of a novel autophagy-related prognostic signature and therapeutic targets in hepatocellular carcinoma.

BACKGROUND: Many studies have indicated that autophagy plays an important role in multiple cancers, including hepatocellular carcinoma (HCC). This study aimed to establish a prognostic signature for HCC based on autophagy-related genes (ARGs) to predict the prognosis of patients. METHODS: The list of ARGs was derived from screening National Center for Biotechnology Information (NCBI)-Gene and Molecular Signatures Database (MSigDB) datasets. Differential analysis was conducted via the R limma package in HCC patients based on The Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression analysis were conducted to identify key prognostic ARGs via the survival package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed by clusterProfiler package. The Estimation of Stromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm was used to conduct immune analysis. Finally, the correlation between the prognostic model and clinical characteristics was also assessed, including age, tumor-node-metastasis (TNM) stages, and tumor grades. RESULTS: Firstly, 106 differential ARGs were identified and 10 candidates were further confirmed via Cox regression analysis, including BAMBI, HIF1A, SERPINE1, EZH2, SLC9A3R1, IGFBP3, HSPB8, DAB2, CXCL1 and PRNP. The receiver operating characteristic (ROC) curve analysis revealed that the ARGs risk model had a well diagnostic positive rate with 1-year area under the curve (AUC) =0.688 and 3-year AUC =0.674. Correlation analysis indicated that only advanced tumor stages were positively associated with high ARGs scores with P=0.0227. There were also significant differences in tumor purity (P=6.71e-05), infiltrating cell analysis (P=7.77e-05), immune analysis (P=7.9e-05), and stromal cells analysis (P=0.0015) in high- and low-risk ARGs samples. The genes HIF1A, IGFBP3, and DAB2 were found to have high frequent missense mutations in samples with high-risk ARGs scores. Lastly, we also established a nomogram to predict overall survival (OS) of HCC by integrating ARGs scores and other clinical parameters. CONCLUSIONS: Our study established an autophagy-related signature for predicting the prognosis of HCC patients, providing a thorough understanding of the underlying mechanisms of autophagy in HCC.

Optimization of multi-angle Magneto-Acousto-Electrical Tomography (MAET) based on a numerical method.

Magneto-Acousto-Electrical Tomography (MAET) is a novel multi-physics imaging method, which promises to offer a unique biophysical property of tissue electrical impedance with the additional benefit of excellent spatial resolution of the ultrasonic imaging. It opens the potential for early diagnosis of cancer by revealing changes of dielectric characteristics. However, direct MAET is unable to image the irregularly-shaped lesions fully due to the dependence on the angle between conductivity boundary and ultrasound beam direction. In this paper, a numerical simulation of multi-angle MAET is presented for an improved image reconstruction for MAET in order to discern irregularly-shaped tumors in different positions. The results show that the conductivity boundary interfaces are invisible in single angle B-mode reconstructed image, wherever the ultrasound beam and conductivity boundary are nearly parallel. When the multi-angle scanning was adopted, the image reconstructed with image rotation method reproduced the original object pattern. Furthermore, the relationship between reconstruction error and the number of angles was also discussed. It is found that 12 angles would be necessary to achieve nearly the optimal reconstruction. Finally, reconstructed images in L2 norm of the error with the measurement noise are presented.

Clinical strategies for differentiating IgG4-related cholecystitis from gallbladder carcinoma to avoid unnecessary surgical resection.

Immunoglobulin G4 (IgG4)-related cholecystitis (IgG4-C) is often difficult to distinguish from gallbladder carcinoma (GBC). This study aimed to determine a practical strategy for differentiating between IgG4-C and GBC to avoid unnecessary surgical resection. The expression of IgG4 in the gallbladder was detected by immunohistochemistry. The clinicopathological and radiological characteristics of IgG4-C patients and GBC patients were analyzed retrospectively. Immunohistochemistry revealed that IgG4 was upregulated in the plasma cells of IgG4-C tissues. The median serum total bilirubin levels were significantly higher in the patients with IgG4-C than in those with GBC (45.8 µmol L-1 vs. 29.9 µmol L-1). The serum γ-GGT levels were higher in IgG4-C patients than in GBC patients, whereas the serum levels of CA125 were significantly higher in GBC patients than in IgG4-C patients. The imaging scans were helpful for differentiating IgG4-C from GBC based on the presence of a layered pattern and Rokitansky-Aschoff sinuses in the gallbladder wall. There were no statistically significant differences in age, presence of abdominal pain, level of emaciation between the two groups. Our study demonstrated that the combination of imaging with serum total bilirubin, γ-GGT and CA125 levels can offer added preoperative diagnostic value and reduce the rate of IgG4-C misdiagnosis.

Dickkopf-1 contributes to hepatocellular carcinoma tumorigenesis by activating the Wnt/ß-catenin signaling pathway.

Dysregulation of dickkopf-related protein 1 (DKK1) expression has been reported in a variety of human cancers. We previously reported that DKK1 was upregulated in hepatocellular carcinoma (HCC). However, the role of DKK1 in HCC remains unclear. This study aimed to investigate the clinical significance and biological functions of DKK1 in HCC. The expression of DKK1 was examined in cirrhotic and HCC tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). DKK1 was silenced or overexpressed in HCC cell lines, and in vitro and in vivo studies were performed. Immunohistochemistry revealed that DKK1 was weakly expressed in cirrhotic tissues (8/22, 36.4%) but upregulated in HCC tissues (48/53, 90.6%, cohort 1). Significant upregulation of DKK1 was observed in 57.6% (19/33, cohort 2) of HCC tissues by qRT-PCR, and the expression of DKK1 was associated with tumor size (P = 0.024) and tumor number (P = 0.019). Genetic depletion of DKK1 impaired the proliferation, colony-forming ability, invasion, and tumor formation of HCC cells (HepG2 and HUH-7). Conversely, forced expression of DKK1 increased the proliferation, colony-forming ability, and invasion of HepG2 and HUH-7 cells in vitro and enhanced tumor formation in vivo. Subsequent investigation revealed that the DKK1-mediated proliferation and tumorigenicity of HepG2 and HUH-7 cells is dependent on the Wnt/ß-catenin signaling pathway. These findings indicate that DKK1 plays an oncogenic role in HCC by activating the Wnt/ß-catenin signaling pathway.

Quantitative analysis of non-alcoholic fatty liver in rats via combining multiple ultrasound parameters.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. The noninvasive and accurate classification of NAFLD is still a challenging problem. In this study we pro- posed a new quantitative ultrasound (QUS) technique, which combined multiple QUS parameters for distinguishing steatosis stages. NAFLD was induced in the livers of 57 rats by gavage feeding with a high fat emulsion, while 8 rats were given a standard diet to serve as controls. Ex vivo ultrasound mea- surement was conducted for capturing the radiofrequency signal. Six QUS parameters were extracted and selected for linear combination. The results show that the overall performance of the combined parameter is better than that of the single QUS parameter. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) while using our proposed method to distinguish mild steatosis (stage S1) from the steatosis under stage S0 are 90.1%, 0.93, 0.88 and 0.97 respectively. In conclusion, the proposed method in this study can make up for the deficiency of single parameter and improve the quantitative staging ability of fatty liver, and thus could play an important role in the diagnosis of NAFLD.

Improved shear wave motion detection using coded excitation for transient elastography.

Transient elastography (TE) is well adapted for use in studying liver elasticity. However, because the shear wave motion signal is extracted from the ultrasound signal, the weak ultrasound signal can significantly deteriorate the shear wave motion tracking process and make it challenging to detect the shear wave motion in a severe noise environment, such as within deep tissues and within obese patients. This paper, therefore, investigated the feasibility of implementing coded excitation in TE for shear wave detection, with the hypothesis that coded ultrasound signals can provide robustness to weak ultrasound signals compared with traditional short pulse. The Barker 7, Barker 13, and short pulse were used for detecting the shear wave in the TE application. Two phantom experiments and one in vitro liver experiment were done to explore the performances of the coded excitation in TE measurement. The results show that both coded pulses outperform the short pulse by providing superior shear wave signal-to-noise ratios (SNR), robust shear wave speed measurement, and higher penetration intensity. In conclusion, this study proved the feasibility of applying coded excitation in shear wave detection for TE application. The proposed method has the potential to facilitate robust shear elasticity measurements of tissue.

Plasma miR-142 accounting for the missing heritability of CYP3A4/5 functionality is associated with pharmacokinetics of clopidogrel.

AIM: To investigate whether plasma miRNAs targeting CYP3A4/5 have an impact on the variance of pharmacokinetics of clopidogrel. MATERIALS & METHODS: The contribution of 13 miRNAs to the CYP3A4/5 gene expression and activity was investigated in 55 liver tissues. The association between plasma miRNAs targeting CYP3A4/5 mRNA and clopidogrel pharmacokinetics was analyzed in 31 patients with coronary heart disease who received 300 mg loading dose of clopidogrel. RESULTS: Among 13 miRNAs, miR-142 was accounting for 12.2% (p = 0.002) CYP3A4 mRNA variance and 9.4% (p = 0.005) CYP3A5 mRNA variance, respectively. Plasma miR-142 was negatively associated with H4 Cmax (r = -0.5269; p = 0.0040) and associated with H4 AUC0-4h (r = -0.4986; p = 0.0069) after 300 mg loading dose of clopidogrel in coronary heart disease patients. CONCLUSION: miR-142 could account for a part of missing heritability of CYP3A4/5 functionality related to clopidogrel activation.

The independent contribution of miRNAs to the missing heritability in CYP3A4/5 functionality and the metabolism of atorvastatin.

To evaluate the independent contribution of miRNAs to the missing heritability in CYP3A4/5 functionality and atorvastatin metabolism, the relationships among three levels of factors, namely (1) clinical characteristics, CYP3A4/5 genotypes, and miRNAs, (2) CYP3A4 and CYP3A5 mRNAs, and (3) CYP3A activity, as well as their individual impacts on atorvastatin metabolism, were assessed in 55 human liver tissues. MiR-27b, miR-206, and CYP3A4 mRNA respectively accounted for 20.0%, 5.8%, and 9.5% of the interindividual variations in CYP3A activity. MiR-142 was an independent contributor to the expressions of CYP3A4 mRNA (partial R(2) = 0.12, P = 0.002) and CYP3A5 mRNA (partial R(2) = 0.09, P = 0.005) but not CYP3A activity or atorvastatin metabolism. CYP3A activity was a unique independent predictor of variability of atorvastatin metabolism, explaining the majority of the variance in reduction of atorvastatin (60.0%) and formation of ortho-hydroxy atorvastatin (78.8%) and para-hydroxy atorvastatin (83.9%). MiR-27b and miR-206 were found to repress CYP3A4 gene expression and CYP3A activity by directly binding to CYP3A4 3'-UTR, while miR-142 was found to indirectly repress CYP3A activity. Our study indicates that miRNAs play significant roles in bridging the gap between epigenetic effects and missing heritability in CYP3A functionality.

Vps4A functions as a tumor suppressor by regulating the secretion and uptake of exosomal microRNAs in human hepatoma cells.

UNLABELLED: The deregulation of microRNAs (miRNAs) plays an important role in human hepatocarcinogenesis. In this study, we highlight exosomes as mediators involved in modulating miRNA profiles in hepatocellular carcinoma (HCC) cells. First, we examined the different miRNA expression profiles in HCC cells and HCC cell-derived exosomes. Next, coculture experiments indicated that HCC cell-derived exosomes promoted the cell growth, migration, and invasion of HCC cells and had the ability to shuttle miRNAs to recipient cells. Further, our data showed that Vps4A, a key regulator of exosome biogenesis, was frequently down-regulated in HCC tissues. The reduction of Vps4A in HCC tissues was associated with tumor progression and metastasis. In vitro studies revealed that Vps4A repressed the growth, colony formation, migration, and invasion of HCC cells. We further investigated the role and involvement of Vps4A in suppressing the bioactivity of exosomes and characterized its ability to weaken the cell response to exosomes. By small RNA sequencing, we demonstrated that Vps4A facilitated the secretion of oncogenic miRNAs in exosomes as well as accumulation and uptake of tumor suppressor miRNAs in cells. A subset of Vps4A-associated miRNAs was identified. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that the phosphatidylinositol-3-kinase/Akt signaling pathway was the most likely candidate pathway for modulation by these miRNAs. Indeed, we proved that the phosphatidylinositol-3-kinase/Akt pathway was inactivated by Vps4A overexpression. CONCLUSION: Exosome-mediated miRNA transfer is an important mechanism of self-modulation of the miRNA expression profiles in HCC cells, and Vps4A may function as a tumor suppressor, which utilizes exosomes as mediators to regulate the secretion and uptake of miRNAs in hepatoma cells; these observations provide new insights into the development of HCC.

Risk factor analysis of perioperative mortality after ruptured bleeding in hepatocellular carcinoma.

AIM: To discuss strategies and prognosis for the emergency treatment of ruptured bleeding in primary hepatocellular carcinoma. METHODS: The retrospective analysis was performed by examining the emergency treatment experiences of 60 cases of ruptured bleeding in primary hepatocellular carcinoma. The treatment methods included surgical tumour resection, transcatheter arterial embolization (TAE) and non-surgical treatment. Univariate and multivariate analyses were performed to identify the risk factors that impacted 30-d mortality in the research groups. RESULTS: The 30-d mortality of all patients was 28.3% (n = 17). The univariate analysis showed that Child-Pugh C level liver function, shock, massive blood transfusion and large tumour volume were risk factors that influenced 30-d mortality. The multivariate analysis showed that shock and massive blood transfusion were independent risk factors that impacted the 30-d mortality of surgical resection. As for the TAE patients, larger tumour volume was a risk factor towards prognosis. CONCLUSION: Radical resection and TAE therapy would achieve better results in carefully selected ruptured hepatocellular tumours.

Analyzing and modeling rheological behavior of liver fibrosis in rats using shear viscoelastic moduli.

The process of liver fibrosis changes the rheological properties of liver tissue. This study characterizes and compares liver fibrosis stages from F0 to F4 in rats in terms of shear viscoelastic moduli. Here two viscoelastic models, the Zener model and Voigt model, were applied to experimental data of rheometer tests and then values of elasticity and viscosity were estimated for each fibrosis stage. The results demonstrate that moderate fibrosis (≤F2) has a good correlation with liver viscoelasticity. The mean Zener elasticity E1 increases from (0.452±0.094) kPa (F0) to (1.311±0.717) kPa (F2), while the mean Voigt elasticity E increases from (0.618±0.089) kPa (F0) to (1.701±0.844) kPa (F2). The mean Zener viscosity increases from (3.499±0.186) Pa·s (F0) to (4.947±1.811) Pa·s (F2) and the mean Voigt viscosity increases from (3.379±0.316) Pa·s (F0) to (4.625±1.296) Pa·s (F2). Compared with viscosity, the elasticity shows smaller variations at stages F1 and F2 no matter what viscoelastic model is used. Therefore, the estimated elasticity is more effective than viscosity for differentiating the fibrosis stages from F0 to F2.

Anticancer drugs cause release of exosomes with heat shock proteins from human hepatocellular carcinoma cells that elicit effective natural killer cell antitumor responses in vitro.

Failure of immune surveillance related to inadequate host antitumor immune responses has been suggested as a possible cause of the high incidence of recurrence and poor overall survival outcome of hepatocellular carcinoma. The stress-induced heat shock proteins (HSPs) are known to act as endogenous "danger signals" that can improve tumor immunogenicity and induce natural killer (NK) cell responses. Exosome is a novel secretory pathway for HSPs. In our experiments, the immune regulatory effect of the HSP-bearing exosomes secreted by human hepatocellular carcinoma cells under stress conditions on NK cells was studied. ELISA results showed that the production of HSP60, HSP70, and HSP90 was up-regulated in both cell lines in a stress-specific manner. After exposure to hepatocellular carcinoma cell-resistant or sensitive anticancer drugs (hereafter referred to as "resistant" or "sensitive" anticancer drug), the membrane microvesicles were actively released by hepatocellular carcinoma cells, differing in their ability to present HSPs on the cell surface, which were characterized as exosomes. Acting as a decoy, the HSP-bearing exosomes efficiently stimulated NK cell cytotoxicity and granzyme B production, up-regulated the expression of inhibitory receptor CD94, and down-regulated the expression of activating receptors CD69, NKG2D, and NKp44. Notably, resistant anticancer drugs enhanced exosome release and generated more exosome-carried HSPs, which augmented the activation of the cytotoxic response. In summary, our findings demonstrated that exosomes derived from resistant anticancer drug-treated HepG2 cells conferred superior immunogenicity in inducing HSP-specific NK cell responses, which provided a clue for finding an efficient vaccine for hepatocellular carcinoma immunotherapy.

High incidence of biliary complications in rat liver transplantation: can we avoid it?

AIM: To investigate how to reduce the incidence of biliary complications in rat orthotopic liver transplantation. METHODS: A total of 165 male Wistar rats were randomly divided into three groups: Group A, orthotropic liver transplantation with modified "two-cuff" technique; Group B, bile duct was cut and reconstructed without transplantation; and Group C, only laparotomy was performed. Based on the approaches used for biliary reconstruction, Group A was divided into two sub-groups:A1 (n = 30), duct-duct reconstruction, and A2 (n = 30), duct-duodenum reconstruction. To study the influence of artery reconstruction on bile duct complication, Group B was divided into four sub-groups: B1 (n = 10), duct-duct reconstruction with hepatic artery ligation, B2 (n = 10), duct-duct reconstruction without hepatic artery ligation, B3 (n = 10), duct-duodenum reconstruction with hepatic artery ligation, and B4 (n = 10), duct-duodenum reconstruction without hepatic artery ligation. The samples were harvested 14 d after operation or at the time when significant biliary complication was found. RESULTS: In Group A, the anhepatic phase was 13.7 ± 1.06 min, and cold ischemia time was 50.5 ± 8.6 min. There was no significant difference between A1 and A2 in the operation duration. The time for biliary reconstruction was almost the same among all groups. The success rate for transplantation was 98.3% (59/60). Significant differences were found in the incidence of biliary complications in Groups A (41.7%), B (27.5%) and C (0%). A2 was more likely to have biliary complications than A1 (50% vs 33.3%). B3 had the highest incidence of biliary complications in Group B. CONCLUSION: Biliary complications are almost inevitable using the classical "two cuff" techniques, and duct-duodenum reconstruction is not an ideal option in rat orthotopic liver transplantation.

Donor liver natural killer cells alleviate liver allograft acute rejection in rats.

BACKGROUND: Liver enriched natural killer (NK) cells are of high immune activity. However, the function of donor liver NK cells in allogeneic liver transplantation (LTx) remains unclear. METHODS: Ten Gy of whole body gamma-irradiation (WBI) from a 60Co source at 0.6 Gy/min was used for depleting donor-derived leukocytes, and transfusion of purified liver NK cells isolated from the same type rat as donor (donor type liver NK cells, dtlNKs) through portal vein was performed immediately after grafting the irradiated liver. Post-transplant survival observation on recipients and histopathological detection of liver grafts were adoptive to evaluate the biological impact of donor liver NK cells on recipients' survival in rat LTx. RESULTS: Transfusion of dtlNKs did not shorten the survival time among the recipients of spontaneous tolerance model (BN to LEW rat) after rat LTx, but prolonged the liver graft survival among the recipients depleted of donor-derived leukocytes in the acute rejection model (LEW to BN rat). Compared to the recipients in the groups which received the graft depleted of donor-derived leukocytes, better survival and less damage in the allografts were also found among the recipients in the two different strain combinations of liver allograft due to transfusion of dtlNKs. CONCLUSIONS: Donor liver NK cells alone do not exacerbate liver allograft acute rejection. Conversely, they can alleviate it, and improve the recipients' survival.