Hepatocellular carcinoma-associated fibroblasts trigger NK cell dysfunction via PGE2 and IDO

Defects in natural killer (NK) cell function are necessary for tumor immune escape, but the underlying regulatory mechanisms in human cancers remain largely unknown. Here we show that fibroblasts derived from hepatocellular carcinoma (HCC) were significantly superior to foreskin-derived fibroblasts at inducing NK cell dysfunction, which is characterized by low expression of cytotoxic molecules and surface markers for cell activation, impaired production of cytokines, and decreased cytotoxicity against K562 cells in vitro. Our results also indicate that PGE2 and IDO, derived from activated fibroblasts, suppress the activation of NK cells and thereby create favorable conditions for tumor progression.

Lenvatinib Combined With Transarterial Chemoembolization as First-Line Treatment for Advanced Hepatocellular Carcinoma: A Phase III, Randomized Clinical Trial (LAUNCH)

PURPOSE

Lenvatinib (LEN) is a first-line therapy for patients with advanced hepatocellular carcinoma (HCC); however, it has shown modest survival benefits. Therefore, we aimed to compare clinical outcomes of LEN combined with transarterial chemoembolization (LEN-TACE) versus LEN monotherapy in patients with advanced HCC.

MATERIALS AND METHODS

This was a multicenter, randomized, open-label, parallel group, phase III trial. Patients with primary treatment-naive or initial recurrent advanced HCC after surgery were randomly assigned (1:1) to receive LEN plus on-demand TACE (LEN-TACE) or LEN monotherapy. LEN was initiated within 3 days after random assignment (initial dose: 12 mg once daily for patients ≥ 60 kg; 8 mg once daily for patients < 60 kg). TACE was initiated one day after LEN initiation. The primary end point was overall survival (OS).

RESULTS

Between June 2019 and July 2021, a total of 338 patients underwent random assignment at 12 centers in China: 170 to LEN-TACE and 168 to LEN. At a prespecified event-driven interim analysis after a median follow-up of 17.0 months, the median OS was significantly longer in the LEN-TACE group (17.8 v 11.5 months; hazard ratio, 0.45; P < .001). The median progression-free survival was 10.6 months in the LEN-TACE group and 6.4 months in the LEN group (hazard ratio, 0.43; P < .001). Patients in the LEN-TACE group had a higher objective response rate according to the modified RECIST (54.1% v 25.0%, P < .001). Multivariable analysis revealed that portal vein tumor thrombus and treatment allocation were independent risk factors for OS.

CONCLUSION

The addition of TACE to LEN improves clinical outcomes and is a potential first-line treatment for patients with advanced HCC.

Tumor-derived exosomal HMGB1 fosters hepatocellular carcinoma immune evasion by promoting TIM-1+ regulatory B cell expansion

BACKGROUND

Regulatory B (Breg) cells represent one of the B cell subsets that infiltrate solid tumors and exhibit distinct phenotypes in different tumor microenvironments. However, the phenotype, function and clinical relevance of Breg cells in human hepatocellular carcinoma (HCC) are presently unknown.

METHODS

Flow cytometry analyses were performed to determine the levels, phenotypes and functions of TIM-1+Breg cells in samples from 51 patients with HCC. Kaplan-Meier plots for overall survival and disease-free survival were generated using the log-rank test. TIM-1+Breg cells and CD8+ T cells were isolated, stimulated and/or cultured in vitro for functional assays. Exosomes and B cells were isolated and cultured in vitro for TIM-1+Breg cell expansion assays.

RESULTS

Patients with HCC showed a significantly higher TIM-1+Breg cell infiltration in their tumor tissue compared with the paired peritumoral tissue. The infiltrating TIM-1+Breg cells showed a CD5highCD24-CD27-/+CD38+/high phenotype, expressed high levels of the immunosuppressive cytokine IL-10 and exhibited strong suppressive activity against CD8+ T cells. B cells activated by tumor-derived exosomes strongly expressed TIM-1 protein and were equipped with suppressive activity against CD8+ T cells similar to TIM-1+Breg cells isolated from HCC tumor tissue. Moreover, the accumulation of TIM-1+Breg cells in tumors was associated with advanced disease stage, predicted early recurrence in HCC and reduced HCC patient survival. Exosome-derived HMGB1 activated B cells and promoted TIM-1+Breg cell expansion via the Toll like receptor (TLR) 2/4 and mitogen-activated protein kinase (MAPK) signaling pathways.

CONCLUSIONS

Our results illuminate a novel mechanism of TIM-1+Breg cell-mediated immune escape in HCC and provide functional evidence for the use of these novel exosomal HMGB1-TLR2/4-MAPK pathways to prevent and to treat this immune tolerance feature of HCC.

Hepatic carcinoma-associated fibroblasts induce IDO-producing regulatory dendritic cells through IL-6-mediated STAT3 activation

Although carcinoma-associated fibroblasts (CAFs) in tumor microenvironments have a critical role in immune cell modulation, their effects on the generation of regulatory dendritic cells (DCs) are still unclear. In this study, we initially show that CAFs derived from hepatocellular carcinoma (HCC) tumors facilitate the generation of regulatory DCs, which are characterized by low expression of costimulatory molecules, high suppressive cytokines production and enhanced regulation of immune responses, including T-cell proliferation impairment and promotion of regulatory T-cell (Treg) expansion via indoleamine 2,3-dioxygenase (IDO) upregulation. Our findings also indicate that STAT3 activation in DCs, as mediated by CAF-derived interleukin (IL)-6, is essential to IDO production. Moreover, IDO inhibitor, STAT3 and IL-6 blocking antibodies can reverse this hepatic CAF-DC regulatory function. Therefore, our results provide new insights into the mechanisms by which CAFs induce tumor immune escape as well as a novel cancer immunotherapeutic approach (for example, targeting CAFs, IDO or IL-6).

Three isoforms of exosomal circPTGR1 promote hepatocellular carcinoma metastasis via the miR449a-MET pathway

BACKGROUND

The role of exosomal circular RNAs (circRNAs) in Hepatocellular carcinoma (HCC) cells with high metastatic potential has been little studied.

METHODS

Exosomal circRNA from cells with non-metastatic (HepG2), low metastatic (97L), and high metastatic (LM3) potential were sequencing. Metastatic-related circRNAs in serum from HCC patients were measured and their association with clinical prognosis was evaluated. Furthermore, candidate functional circRNAs in LM3-derived exosomes was assessed.

FINDINGS

LM3 exosomes enhanced the cell migration and invasion potential of HepG2 and 97 L cells. CircPTGR1, a circRNA with three isoforms, was specifically expressed in exosomes from 97 L and LM3 cells, upregulated in serum exosomes from HCC patients and was associated with the clinical stage and prognosis. Knockdown of circPTGR1 expression suppressed the migration and invasion of HepG2 and 97L cells induced by co-culturing with LM3 exosomes. Bioinformatics, co-expression analysis, and a luciferase assay indicated that circPTGR1 competed with MET to target miR449a.

INTERPRETATION

Higher metastatic HCC cells can confer this potential on those with lower or no metastatic potential via exosomes with circPTGR1, resulting in increased migratory and invasive abilities in those cells. FUND: National Natural Science Foundation of China (No. 81470870, 81670601, 81570593), Guangdong Natural Science Foundation (No. 2015A030312013, 2015A030313038), Sci-tech Research Development Program of Guangdong Province (2014B020228003), Sci-tech Research Development Program of Guangzhou City (No. 201508020262, 201400000001-3, 201604020001, 201607010024), Innovative Funds for Small and Medium-Sized Enterprises of Guangdong Province (2016A010119103), Pearl River S&T Nova Program of Guangzhou (201710010178), and National 13th Five-Year Science and Technology Plan Major Projects of China (No. 2017ZX10203205-006-001).

Cancer-associated fibroblasts from hepatocellular carcinoma promote malignant cell proliferation by HGF secretion

Cancer-associated fibroblasts (CAFs) are reported to support tumorigenesis by stimulating angiogenesis, cancer cell proliferation, and invasion in most solid tumors. However, the roles of CAFs in the liver cancer microenvironment have not been thoroughly studied. In our previous study, we successfully isolated CAFs from hepatocellular carcinoma (HCC) (H-CAFs) and proved that H-CAFs suppressed the activation of NK cells and thereby created favorable conditions for HCC progression. In our present study, we found that the proliferation of MHCC97L and Hep3B cells was significantly promoted by treatment with conditioned medium from H-CAFs. Pathological analysis also revealed that H-CAFs increased the proportion of Ki-67 (+) malignant cells and prevented them from undergoing necrosis. Moreover, the concentration of hepatocyte growth factor (HGF) cytokine in the conditioned medium of H-CAFs was higher than conditioned medium from normal skin fibroblasts (NSFs). Anti-HGF significantly reduced the proliferation-promoting capability of H-CAFs. In addition, we found that the abundance of H-CAFs correlated positively with tumor size. These results indicate that H-CAFs are an important factor for promoting the growth of HCC in vitro and in vivo, and that HGF plays a key role in HCC proliferation induced by H-CAFs.

Preoperative identification of microvascular invasion in hepatocellular carcinoma by XGBoost and deep learning

PURPOSE

Microvascular invasion (MVI) is a valuable predictor of survival in hepatocellular carcinoma (HCC) patients. This study developed predictive models using eXtreme Gradient Boosting (XGBoost) and deep learning based on CT images to predict MVI preoperatively.

METHODS

In total, 405 patients were included. A total of 7302 radiomic features and 17 radiological features were extracted by a radiomics feature extraction package and radiologists, respectively. We developed a XGBoost model based on radiomics features, radiological features and clinical variables and a three-dimensional convolutional neural network (3D-CNN) to predict MVI status. Next, we compared the efficacy of the two models.

RESULTS

Of the 405 patients, 220 (54.3%) were MVI positive, and 185 (45.7%) were MVI negative. The areas under the receiver operating characteristic curves (AUROCs) of the Radiomics-Radiological-Clinical (RRC) Model and 3D-CNN Model in the training set were 0.952 (95% confidence interval (CI) 0.923-0.973) and 0.980 (95% CI 0.959-0.993), respectively (p = 0.14). The AUROCs of the RRC Model and 3D-CNN Model in the validation set were 0.887 (95% CI 0.797-0.947) and 0.906 (95% CI 0.821-0.960), respectively (p = 0.83). Based on the MVI status predicted by the RRC and 3D-CNN Models, the mean recurrence-free survival (RFS) was significantly better in the predicted MVI-negative group than that in the predicted MVI-positive group (RRC Model: 69.95 vs. 24.80 months, p < 0.001; 3D-CNN Model: 64.06 vs. 31.05 months, p = 0.027).

CONCLUSION

The RRC Model and 3D-CNN models showed considerable efficacy in identifying MVI preoperatively. These machine learning models may facilitate decision-making in HCC treatment but requires further validation.

Colorectal carcinoma-derived fibroblasts modulate natural killer cell phenotype and antitumor cytotoxicity

Substantial evidence indicates that cancer-associated fibroblasts (CAFs) are critical components in the process of cancer progression. However, the role of CAFs in the immunopathogenesis of human cancer remains elusive. In this study, we demonstrate that purified colorectal carcinoma-derived fibroblasts exhibit activated phenotypes characterized by substantial α-smooth muscle actin expression. These CAFs sharply suppress natural killer (NK) cell functions in co-culture experiments. In contrast, normal skin fibroblasts had only a minimal effect on NK cell phenotype and function. Moreover, we demonstrated that prostaglandin E2 (PGE2) was released by fibroblasts in co-culture experiments. Thus, the functional modulation of NK cells by CAFs may represent a novel mechanism linking the pro-inflammatory response to immune tolerance within the tumor milieu.

Cancer-associated Fibroblasts induce epithelial-mesenchymal transition via the Transglutaminase 2-dependent IL-6/IL6R/STAT3 axis in Hepatocellular Carcinoma

Cancer-associated fibroblasts (CAFs) play crucial roles in enhancing cell survival, proliferation, invasion, and metastasis. We previously showed that hepatocellular carcinoma-derived CAFs (H-CAFs) promoted proliferation of hepatocellular carcinoma (HCC) cells. This study aimed to further explore the role of CAFs in HCC epithelial-mesenchymal transition (EMT) and the underlying mechanism. High CAF density was significantly associated with liver cirrhosis, inferior clinicopathologic characteristics, elevated EMT-associated markers, and poorer survival in human HCC. Within HCC cells, EMT was induced after co-culture with H-CAFs. Secretomic analysis showed that IL-6 and HGF were the key EMT-stimulating cytokines secreted by H-CAFs. Proteomic analysis revealed that TG2 was significantly upregulated in HCC cells with EMT phenotypes. Overexpression of TG2 promoted EMT of HCC cells, and knockdown of TG2 remarkably attenuated the H-CAF-induced EMT. Furthermore, during EMT, TG2 expression was enhanced after HCC cells were stimulated by IL-6, but not HGF. Inhibition of the IL-6/STAT3 signaling decreased TG2 expression. The principal TG2 transcription control element and a potential STAT3 binding site were identified using promoter analysis. Hence, H-CAFs facilitates HCC cells EMT mediated by IL-6, which in turn activates IL-6/IL6R/STAT3 axis to promote TG2 expression.

A scoring model based on neutrophil to lymphocyte ratio predicts recurrence of HBV-associated hepatocellular carcinoma after liver transplantation

BACKGROUND

Neutrophil to lymphocyte ratio (NLR) has been proposed to predict prognosis of hepatocellular carcinoma (HCC). However, the cut-off values are empirical. We determined the optimal cut-off value to predict HCC recurrence after liver transplantation (LT) and further established a scoring model based on NLR.

METHODOLOGY/PRINCIPAL FINDINGS

We analyzed the outcome of 101 HBV-associated HCC patients undergoing LT. Preoperative risk factors for tumor recurrence were evaluated by univariate analysis. By using ROC analysis, NLR≥3 was considered elevated. The disease-free survival (DFS) and overall survival (OS) for patients with high NLR was significantly worse than that for patients with normal NLR (the 5-year DFS and OS of 28.5% and 19.5% vs. 64.9% and 61.8%, respectively; P<0.001). Univariate analysis revealed that tumor size >5 cm, tumor number >3, macrovascular invasion, AFP≥400 µg/L, NLR≥3, and HBV-DNA level >5 log10 copies/mL were preoperative predictors of DFS. Cox regression analysis showed macrovascular invasion, tumor number, and high NLR were independent prognostic factors. We then established a preoperative prognostic score based on multivariate analysis. Each factor was given a score of 1. Area under the ROC curve of the score was 0.781. All nine patients with score 3 developed recurrence within 6 months after LT. Of 71 patients without vascular invasion, three patients with both tumor number >3 and NLR≥3 developed recurrence within 14 months after LT while the 5-year DFS and OS for patients with a score of 0 or 1 were 68.1% and 62.8%, respectively.

CONCLUSIONS/SIGNIFICANCE

Preoperative elevated NLR significantly increases the risk of recurrence in patients underwent LT for HCC. Patients with both NLR≥3 and tumor number >3 are not a good indication for LT. Our score model may aid in the selection of patients that would most benefit from transplantation for HCC.

Umbilical cord-derived mesenchymal stem cells instruct dendritic cells to acquire tolerogenic phenotypes through the IL-6-mediated upregulation of SOCS1

The mechanisms responsible for the inhibitory effects of mesenchymal stem cells (MSCs) on dendritic cells (DCs) are still poorly understood. Our investigation of the potential signaling pathways revealed for the first time that human umbilical-cord-derived MSCs (UC-MSCs) instruct DCs to acquire tolerogenic phenotypes through the IL-6-mediated upregulation of SOCS1. This subset of MSC-DCs exhibited a tolerogenic pattern, with a clear decrease in the expression of co-stimulatory molecules and the capacity to stimulate CD3(+) T cell proliferation and inflammatory factor secretion, and a significant increase in the production of inhibitory cytokine IL-10 and the ability to induce Treg cells and Th2 responses. Adoption of this tolerogenic pattern required the activation of SOCS1, which blocked DC maturation by impairing TLR4 signaling. The effects of UC-MSCs on SOCS1 activation were essentially mediated by the JAK-STAT pathway via IL-6 secretion. In summary, our data identify a new mechanism, involving the IL-6-mediated upregulation of SOCS1, by which UC-MSCs instruct DCs to acquire tolerogenic phenotypes.

Bone marrow mesenchymal stem cells ameliorate hepatic ischemia/reperfusion injuries via inactivation of the MEK/ERK signaling pathway in rats

BACKGROUND

Primary graft dysfunction or nonfunction after liver transplantation, which is usually caused by ischemia/reperfusion injury (IRI), is a serious clinical problem. Although bone marrow mesenchymal stem cells (MSCs) have shown great potential in cell therapy for IRI in several organs, the mechanism(s) by which MSCs offer protection is unclear.

METHODS

In the present study, we injected MSCs systemically via the tail vein in the rat model of 70% hepatic IRI and measured the biochemical and pathologic alterations to evaluate the therapeutic effect of MSC transplantation. Concurrently, H(2)O(2) was used in vitro to mimic oxidative injury and to induce apoptosis in the human normal liver cell line LO2 to evaluate the protective effects of mesenchymal stem cell conditioned medium (MSC-CM) on LO2 cells.

RESULTS

The systemic infusion of MSCs led to a significant prevention of liver enzyme release and an improvement in the histology of the acutely injured liver. In vitro assays demonstrated that MSC-CM promoted hepatocyte proliferation and had a direct inhibitory effect on hepatocyte apoptosis induced by H(2)O(2). In addition, we demonstrated that the prevention of MEK/ERK pathway activation played a pivotal role in the protection.

CONCLUSIONS

These data suggest that MSC may represent a potential therapeutic strategy to alleviate hepatic ischemia/reperfusion injuries after liver transplantation via inactivation of the MEK/ERK signaling pathway.

Downregulation of miR-432 activates Wnt/β-catenin signaling and promotes human hepatocellular carcinoma proliferation

Sustained cell growth and proliferation, one of the hallmarks of cancer, is considered to responsible for cancer-related deaths by disorganizing the balance of growth promotion and growth limitation. Aberrant activation of the Wnt/β-catenin signaling pathway leads to cell proliferation, growth and survival, and promotes the development of various human tumors, including hepatocellular carcinoma. Elucidating the molecular mechanism of this abnormality in hepatocellular carcinoma carcinogenesis may improve diagnostic and therapeutic strategies for this malignancy. Herein, we report that the expression of miR-432 was markedly downregulated in hepatocellular carcinoma cell lines and tissues, and upregulation of miR-432 inhibited, whereas downregulation of miR-432 enhanced the proliferation and tumorigenicity of hepatocellular carcinoma cells both in vitro and in vivo. Furthermore, miR-432 directly targeted and suppressed multiple regulators of the Wnt/β-catenin signaling cascade, including LRP6, TRIM29 and Pygo2, which subsequently deactivated Wnt/β-catenin signaling pathway. Finally, miR-432 expression was inversely correlated with three targets in clinical hepatocellular carcinoma samples. These results demonstrated that miR-432 functions as a tumor-suppressive miRNA by suppressing Wnt/β-catenin signaling activation and may represent a therapeutic target for hepatocellular carcinoma.

Four waves of hepatocyte proliferation linked with three waves of hepatic fat accumulation during partial hepatectomy-induced liver regeneration

Partial hepatectomy (PH) triggers hepatocyte proliferation-mediated liver repair and is widely used to study the mechanisms governing liver regeneration in mice. However, the dynamics of the hepatocyte proliferative response to PH remain unclear. We found that PH-induced mouse liver regrowth was driven by four consecutive waves of hepatocyte replication. The first wave exhibited the highest magnitude followed by two moderate waves and one minor wave. Underlying this continuous hepatocyte replication was persistent activation of cell cycle components throughout the period of liver regeneration. Hepatocyte mitotic activity in the first three proliferative cycles showed a circadian rhythm manifested by three corresponding mitosis peaks, which were always observed at Zeitgeber time 0. The Bmal1-Clock/Wee1/Cdc2 pathway has been proposed by others to govern the circadian rhythm of hepatocyte mitosis during liver regeneration. However, we did not observe the correlations in the expression or phosphorylation of these proteins in regenerating livers. Notably, Bmal1 protein displayed frequent changes in hepatic distribution and cellular localization as the liver regrowth progressed. Further, three waves of hepatic fat accumulation occurred during hepatic regeneration. The first started before and lasted through the first round of hepatocyte proliferation, whereas the second and third occurred concomitantly with the second and third mitotic peaks, respectively.

CONCLUSION

PH-induced liver regeneration consists of four continuous waves of hepatocyte proliferation coupled with three waves of hepatic fat accumulation. Bmal1, Wee1, and Cdc2 may not form a pathway regulating the circadian rhythm of hepatocyte mitosis during liver regeneration.

Therapeutic potentials of umbilical cord-derived mesenchymal stromal cells for ischemic-type biliary lesions following liver transplantation

BACKGROUND AIMS

Ischemic-type biliary lesions are severe, graft-threatening complications after orthotopic liver transplantation, and a novel and efficient therapeutic strategy is urgently needed. Due to the immunosuppressive and regenerative properties, mesenchymal stromal cells (MSCs) could be an interesting candidate.

METHODS

We initiated safety and efficacy of human umbilical cord-derived MSC (UC-MSC) transfusions for patients with ischemic-type biliary lesions after liver transplantation. From January 2013 to June 2014, 12 ischemic-type biliary lesions patients were recruited as the MSCs group in this phase I, prospective, single-center clinical study. Patients in this group received six doses of UC-MSCs (about 1.0 × 106 MSCs per kilogram body weight through peripheral intravenous infusion). The traditional therapeutic protocol was applied during October 2003 to December 2012 in 70 ischemic-type biliary lesions patients who were treated as the control group. Liver function tests, the need for interventional therapies and graft survival rate were chosen to evaluate the therapeutic efficacy of MSC treatment. Adverse events were closely monitored up to 2 years after MSC transfusions.

RESULTS

No significant MSC-related adverse events were observed during the trial. Compared with baseline, the levels of total bilirubin, γ-glutamyl transferase and alkaline phosphatase were decreased after UC-MSC treatment at week 20 and week 48. Interventional therapies were performed in 64.3% (45/70) of patients in the control group and 33.3% (4/12) of patients in the MSCs groups. MSC therapy significantly decreased the need for interventional therapies (P = 0.046). The 1- and 2-year graft survival rates were higher in the MSCs group (100% and 83.3%, respectively) than in the control group (72.9% and 68.6%, respectively).

CONCLUSIONS

The UC-MSC transfusions are clinically safe and short-term favorable, which may become a novel treatment for patients with ischemic-type biliary lesions after liver transplantation.

The impacts of pretreatment circulating eosinophils and basophils on prognosis of stage Ⅰ-Ⅲ colorectal cancer

AIM

The effects of circulating eosinophils and basophils on cancer survival are unclear. Here, we aimed to explore the impacts of eosinophils and basophils on prognosis of stage I-III colorectal cancer (CRC) patients.

METHODS

From February 2003 to March 2013, 569 stage I-III CRC patients were enrolled in this retrospective study. The associations between pretreatment circulating eosinophils, basophils and CRC overall survival (OS), disease-free survival (DFS) were investigated. Moreover, the prognostic value of combined eosinophils/basophils and neutrophil to lymphocyte ratio (NLR)/platelet to lymphocyte ratio (PLR) was investigated.

RESULTS

Kaplan-Meier methods showed the associations of eosinophils < 0.095 × 109 /L and shorter OS (P < 0.0001), eosinophils < 0.055 × 109 /L and shorter DFS (P < 0.0001), basophils < 0.015 × 109 /L and shorter OS (P = 0.001), basophils < 0.015 × 109 /L and shorter DFS (P = 0.005). Cox regression model showed that eosinophils < 0.095 × 109 /L (hazard ratio [HR], 1.723; 95% confidence intervals [CI] = 1.177-2.523) and basophils < 0.015 × 109 /L (HR, 1.714; 95% CI = 1.152-2.548) were independent prognostic factors for OS, and eosinophils < 0.055 × 109 /L (HR, 2.309; 95% CI = 1.587-3.361) and basophils < 0.015 × 109 /L (HR, 1.397; 95% CI = 1.003-1.945) were independent prognostic factors for DFS, respectively. The combined eosinophil-PLR (HR, 2.611; 95% CI = 1.328-5.130) and basophil-PLR (HR, 2.520; 95% CI = 1.240-5.123) were the independent prognostic factors for OS. The combined eosinophil-NLR (HR, 2.770; 95% CI = 1.528-5.019) and eosinophil-PLR (HR, 4.788; 95% CI = 2.458-9.329) were the independent prognostic factors for DFS.

CONCLUSION

Pretreatment circulating eosinophils < 0.095 × 109 /L/0.055 × 109 /L and circulating basophils < 0.015 × 109 /L have significant impacts on prognosis of stage I-III CRC patients.

NRF2 overexpression in mesenchymal stem cells induces stem-cell marker expression and enhances osteoblastic differentiation

Hypoxic environment has been suggested in stem cell culturing as their physiologic niche requires oxygen tension to maintain stemness. The administration of cobalt chloride (CoCl2) was widely applied in mimicking hypoxia for its economic advantages and convenience. We confirmed that CoCl2 could maintain stemness and promote the osteogenesis capacity of MSCs. However, CoCl2 could induce the apoptosis and hinder the proliferation of MSCs. To find out a potential method maintaining their stemness without threatening their survival, we analyzed the database of Gene Expression Omnibus (GEO) and proposed that NRF2 (nuclear factor erythroid-derived 2-like 2) might be the potential target. We found that knocking down NRF2 expression in MSCs impaired the expression of stem cell markers and the osteogenesis process even under hypoxic environment, but with NRF2 overexpression, the proliferation of MSCs was increased with significantly reduced rate of apoptosis. Therefore, our findings suggested that overexpressing NRF2 could be a potential method for maintaining stemness and preventing apoptosis in MSCs under oxidative stress.

Downregulation of miR-610 promotes proliferation and tumorigenicity and activates Wnt/β-catenin signaling in human hepatocellular carcinoma

BACKGROUND

Wnt/β-catenin signaling pathway plays important roles in human cancer progression. Better understanding the mechanism underlying regulation of Wnt/β-catenin signaling pathway might provide novel therapeutic targets for cancer treatment.

METHODS

miR-610 expression levels in hepatocellular carcinoma (HCC) cell lines, HCC tissues and 76 archived HCC specimens were determined using real-time PCR. Cell viability was measured by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. The level of DNA synthesis was determined by BrdU incorporation assay. Flow cytometry analysis was used to analyze cell cycle progression. The cells proliferation and tumorigenesis were determined by colony formation and anchorage-independent growth assays in vitro, and by xenograft tumors in vivo. Luciferase assay and micro-ribonucleoprotein complex immunoprecipitation assay were used to confirm the association of the targeted mRNAs with miR-610.

RESULTS

miR-610 was downregulated in human HCC cells and tissues, and correlated with HCC progression and patient survival. Inhibition of miR-610 promoted, but overexpression of miR-610 reduced, HCC cell proliferation and tumorigenicity both in vitro and in vivo. Furthermore, we found that inhibiting miR-610 activated, but overexpressing miR-610 decreased, the Wnt/β-catenin activity through directly suppressing lipoprotein receptor-related protein 6 (LRP6) and transducin β-like protein 1 (TBL1X). The in vitro analysis was consistent with the inverse correlation detected between miR-610 levels with expression of LRP6 and TBL1X in a cohort of human HCC samples.

CONCLUSIONS

Our results indicate that miR-610 downregulation plays essential roles in HCC progression and reduced miR-610 is correlated with Wnt/β-catenin signaling pathway.

MiR-501-5p regulates CYLD expression and promotes cell proliferation in human hepatocellular carcinoma

OBJECTIVE

Previous studies have shown that the micro-ribonucleic acid miR-501-5p is upregulated in hepatocellular carcinoma cells and tissues with high hepatitis B virus replication, and that miR-501 overexpression significantly promotes hepatitis B virus replication. We further analysed a published microarray-based high-throughput dataset (NCBI/GEO/GSE36915) and found that miR-501-5p was upregulated in hepatocellular carcinoma tumour tissues. We therefore investigated the possible function of miR-501-5p during the development of hepatocellular carcinoma.

METHODS

Expression of miR-501-5p in human hepatocellular carcinoma specimens and cell lines was assessed, using real-time polymerase chain reaction. Luciferase reporter assays were used to confirm CYLD as a target of miR-501-5p. The effect of miR-501-5p on cell proliferation was confirmed, using tetrazolium and colony formation assays. Gene and protein expression were examined, using real-time polymerase chain reaction and western blotting, respectively.

RESULTS

MiR-501-5p was upregulated in hepatocellular carcinoma specimens and cell lines, and directly targeted the 3' untranslated region of CYLD. MiR-501-5p upregulation corresponded with a downregulation of CYLD in the same tissues and cell lines, and overexpression of MiR-501-5p decreased CYLD expression, increased expression of cyclin D1 and c-myc and promoted the proliferation of hepatocellular carcinoma cells in vitro.

CONCLUSIONS

This study suggests that miR-501-5p may play an important role in the development of hepatocellular carcinoma by promoting cell proliferation, and indicates that miR-501-5p may represent a novel therapeutic target for hepatocellular carcinoma.

Efficacy of Hepatic Resection vs. Radiofrequency Ablation for Patients With Very-Early-Stage or Early-Stage Hepatocellular Carcinoma: A Population-Based Study With Stratification by Age and Tumor Size

Background: Because of the poor health conditions of elderly patients (age >65) with very-early-stage and early-stage hepatocellular carcinoma (HCC), primary treatment via hepatic resection (HR), or radiofrequency ablation (RFA) must be considered. However, few studies have examined this issue. Methods: A retrospective cohort was obtained from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Patients were grouped by tumor size (0-20, 21-30, 31-35, and 31-50 mm) and age (>65 and ≤65). Overall survival (OS) and disease-specific survival (DSS) were assessed. Results: In total, 1912 patients aged >65 and 2,784 patients aged ≤65 were analyzed after propensity score matching (PSM). For patients >65 with tumors ≤20 mm, OS and DSS did not differ significantly between the RFA and HR groups (p = 0.47 and p = 0.76, respectively). For patients with tumors measuring 21-30 mm, the HR group had better OS and a trend toward better DSS compared with the RFA group (p = 0.03 and p = 0.09, respectively). For patients with tumors measuring 31-50 mm, the HR group had better OS and DSS compared with the RFA group (p < 0.001 for both). For patients <65, the HR group had better OS and DSS compared with the RFA group for all tumor sizes. Conclusions: For elderly patients (age >65), RFA is recommended for tumors ≤20 mm. For patients older than 65 with tumors measuring 21-50 mm and for those younger than 65 with tumors of any size, HR is the better choice.

Aging aggravates hepatic ischemia-reperfusion injury in mice by impairing mitophagy with the involvement of the EIF2α-parkin pathway

Hepatic ischemia-reperfusion (I/R) injury fundamentally influences the performance of aged liver grafts. The significance of mitophagy in the age dependence of sensitivity to I/R injury remains poorly understood. Here, we show that aging aggravated hepatic I/R injury with decreased mitophagy in mice. The enhancement of mitophagy resulted in significant protection against hepatic I/R injury. Parkin, an E3 ubiquitin ligase, was found depleted by I/R in aged livers. In oxygen-glucose deprivation reperfusion (OGD-Rep.)-treated L02 cells, parkin silencing impaired mitophagy and aggravated cell damage through a relative large mitochondrial membrane potential transition. The phosphorylation of the endoplasmic reticulum stress response protein EIF2α, which was also reduced in the aged liver, induced parkin expression both in vivo and vitro. Forty-six hepatic biopsy specimens from liver graft were collected 2 hours after complete revascularization, followed by immunohistochemical analyses. Parkin expression was negatively correlated to donor age and the peak level of aspartate aminotransferase within first week after liver transplantation. Our translational study demonstrates that aging aggravated hepatic I/R injury by impairing the age-dependent mitophagy function via an insufficient parkin expression and identifies a new strategy to evaluate the capacity of an aged liver graft in the process of I/R through the parkin expression.

Yes-associated protein expression is a predictive marker for recurrence of hepatocellular carcinoma after liver transplantation

PURPOSE

To explore the expression of Yes-associated protein (YAP) in hepatocellular carcinoma (HCC) patients, and assess its prognostic value to recurrence of HCC after liver transplantation (LT).

METHODS

Collected data of 105 consecutive patients undergoing LT for HCC were analyzed retrospectively. The immunohistochemistry was used to detect the expression of YAP, Mst1, Lats1/2, pYAP, pLats1/2 and pMst1/2 in tumor tissues. Contingency table and χ(2)-test were used to investigate the correlation between expression of YAP, Mst1, Lats1/2 and clinical characteristics. Univariate survival analysis and Multivariate Cox regression analysis were also performed to analyze the correlation of clinical and pathological factors with tumor recurrence after LT. The Kaplan-Meier method and log-rank test were used to analyze HCC-specific disease-free survival (DFS) rate.

RESULTS

Forty patients fulfilled Milan criteria with 1-, 2-, 3- and 5-years DFS of 86.7, 84.6, 84, 84%, respectively. The positive rates of YAP, Lats1/2, Mst1 in HCC were 51.4, 45.7, 64.8%, respectively. YAP expression in HCC tumors was significantly associated with tumor size (p = 0.041), venous infiltration (p = 0.002), AJCC tumor stage (p = 0.027). Lats1/2 expression was significantly associated with tumor size (p = 0.001) and AJCC tumor stage (p = 0.019). Mst1 expression was also significantly associated with tumor size (p = 0.042). HCC-specific DFS was significantly longer for patients with YAP negative expression compared with patients with YAP positive expression (1-, 2-, 3- and 5-years DFS of 71.7, 65.3, 65.3, 65.3 vs. 42.5, 36.6, 32.5, 30.4%, respectively, log-rank = 12.89, p < 0.001). Multivariate Cox regression analysis indicated that YAP expression (HR = 2.011, p = 0.020) in HCC was an independent prognostic factor for HCC-specific DFS after liver transplantation.

CONCLUSIONS

YAP is an independent prognostic marker for tumor recurrence for HCC patients after liver transplantation.

High hepatitis B virus DNA level in serum before liver transplantation increases the risk of hepatocellular carcinoma recurrence

AIM

To analyze the relationship between hepatitis B virus (HBV) and hepatocellular carcinoma (HCC) recurrence in orthotopic liver transplantation (OLT) patients.

METHODS

340 HBV patients with OLT were included in the study; among them were 148 patients with HBV-associated HCC.

RESULTS

HCC recurrence rates at 1, 3 and 5 years were 21, 29, and 46%, respectively. Exceeding Milan criteria (hazard ratio, HR = 12.35; 95% confidence interval, CI, 2.80-54.49; p = 0.001), HBV DNA level >5 log(10) copies/ml before transplant (HR = 2.45; 95% CI 1.10-5.45; p = 0.03) and HBV recurrence (HR = 2.27; 95% CI 1.10-4.75; p = 0.03) were significant independent predictors of HCC recurrence. HBV DNA >5 log(10) copies/ml before transplant (HR = 8.65; 95% CI 3.40-21.98; p < 0.001) and concomitance with HCC (HR = 2.79; 95% CI 1.33-5.87; p = 0.007) were predictors of HBV recurrence. Further stratified analysis showed that HBV recurrence was more prevalent in the HCC recurrence group (HR = 4.58; 95% CI 1.88-11.12; p = 0.001).

CONCLUSIONS

There is a close relationship between HBV and HCC recurrence after transplant. High HBV DNA levels before transplant are associated with HCC recurrence after transplant.

Enhanced antitumor efficacy of a novel fiber chimeric oncolytic adenovirus expressing p53 on hepatocellular carcinoma

Oncolytic adenoviruses may offer a new treatment option and improve the prognosis for patients with hepatocellular carcinoma (HCC). However, the antitumor efficacy of oncolytic adenoviruses on HCC cells is compromised due to low expression of the adenovirus serotype 5 (Ad5) receptor on the target cells. In this study we showed that all HCC cell lines and clinical samples expressed high level of CD46, the receptor for Adenovirus 35 (Ad35) and constructed new fiber chimeric oncolytic adenoviruses with or without a p53 gene expression cassette, SG635-p53 and SG635, respectively. These variants were derived from the previously described Ad5 vectors SG600-p53 and SG600 by replacing the Ad5 fiber with a chimeric Ad5/35 fiber. It was found that the 5/35 fiber chimeric adenovirus vector (Ad5/35-EGFP) demonstrated significantly improved transduction in all tested HCC cell lines compared with the Ad5 vector (Ad5-EGFP). The new fiber chimeric oncolytic adenoviruses produced more progeny viruses in HCC cells than did the Ad5-based viruses but replicated weakly in normal fibroblast BJ cells. In addition, SG635-p53 mediated a higher level of transgenic expression than SG600-p53 in Hep3B and Huh7 cells and showed a markedly enhanced antitumor effect on HCC cells in vitro compared with SG635 or SG600-p53 without causing significant cytotoxicity to normal cells. Antitumor activity of SG635-p53 was shown in Hep3B subcutaneous xenograft tumor models following intratumoral injection, resulting in significant inhibition of tumor growth and prolonged survival of animals. Our data suggest that SG635-p53, as a fiber chimeric oncolytic adenovirus in combination with p53 expression, may serve as a novel, promising and safe anticancer agent for the treatment of HCC.