Protein kinase C delta enhances the diagnostic performance of hepatocellular carcinoma.

BACKGROUND: The conventional markers for hepatocellular carcinoma (HCC), α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP), have several limitations; both have low sensitivity in patients with early-stage HCC; low sensitivity for AFP with HCC after eliminating hepatitis C virus (HCV); low specificity for DCP in patients with non-viral HCC, which is increasing worldwide; low specificity for AFP in patients with liver injury; and low specificity for DCP in patients treated with warfarin. To overcome these issues, the identification of novel biomarkers is an unmet need. OBJECTIVE: This study aimed to assess the usefulness of serum protein kinase C delta (PKCδ) for detecting these HCCs. METHODS: PKCδ levels were measured using a sandwich enzyme-linked immunosorbent assay in 363 chronic liver disease (CLD) patients with and without HCC. RESULTS: In both viral and non-viral CLD, PKCδ can detect HCCs with high sensitivity and specificity, particularly in the very early stages. Notably, the value and sensitivity of PKCδ were not modified by HCV elimination status. Liver injury and warfarin administration, which are known to cause false-positive results for conventional markers, did not modify PKCδ levels. CONCLUSIONS: PKCδ is an enhanced biomarker for the diagnosis of HCC that compensates for the drawbacks of conventional markers.

A novel combined C-reactive protein-albumin ratio and modified albumin-bilirubin score can predict long-term outcomes in patients with hepatocellular carcinoma after hepatic resection.

Background: Systemic inflammatory response represented by C-reactive protein and albumin ratio (CAR) and modified albumin-bilirubin (mALBI) grade both have been associated with long-term outcome in patients with hepatocellular carcinoma (HCC). In this study, we investigated the prognostic utility of combined score of CAR and mALBI score to predict the prognosis of HCC patients after hepatic resection. Methods: This study included 214 patients who had undergone primary hepatic resection for HCC between 2008 and 2018. Systemic inflammatory response and mALBI were evaluated preoperatively and patients were classified into three groups based on the combination of CAR and mALBI score: low CAR and low mALBI grade (score 0), either high CAR or high mALBI grade (score 1), and both high CAR and high mALBI grade ≥2b (score 2). Multivariate Cox proportional hazard models were conducted to assess disease-free and overall survival. Results: In multivariate analysis, sex (p < 0.01), HBsAg positivity (p < 0.01), serum AFP level ≥20 ng/mL (p < 0.01), microvascular invasion (p = 0.02), multiple tumors (p < 0.01), type of resection (p < 0.01), and CAR-mALBI score ≥2 (HR 2.19, 95% CI 1.39-3.44, p < 0.01) were independent prognostic factors of disease-free survival, while sex (p = 0.01), HBsAg positivity (p < 0.01), poor tumor differentiation (p = 0.03), multiple tumors (p < 0.01), CAR-mALBI score ≥2 (HR 2.70, 95% CI 1.51-4.83, p < 0.01) were independent prognostic factors of overall survival. Conclusions: CAR-mALBI score is associated with disease-free and overall survival in patients with HCC after hepatic resection, suggesting the importance of evaluating both hepatic functional reserve and host-inflammatory state in the risk assessment of HCC patients.

Fibrolamellar carcinomas-growth arrested by paracrine signals complexed with synthesized 3-O sulfated heparan sulfate oligosaccharides.

Fibrolamellar carcinomas (FLCs), lethal tumors occurring in children to young adults, have genetic signatures implicating derivation from biliary tree stem cell (BTSC) subpopulations, co-hepato/pancreatic stem cells, involved in hepatic and pancreatic regeneration. FLCs and BTSCs express pluripotency genes, endodermal transcription factors, and stem cell surface, cytoplasmic and proliferation biomarkers. The FLC-PDX model, FLC-TD-2010, is driven ex vivo to express pancreatic acinar traits, hypothesized responsible for this model's propensity for enzymatic degradation of cultures. A stable ex vivo model of FLC-TD-2010 was achieved using organoids in serum-free Kubota's Medium (KM) supplemented with 0.1% hyaluronans (KM/HA). Heparins (10 ng/ml) caused slow expansion of organoids with doubling times of ∼7-9 days. Spheroids, organoids depleted of mesenchymal cells, survived indefinitely in KM/HA in a state of growth arrest for more than 2 months. Expansion was restored with FLCs co-cultured with mesenchymal cell precursors in a ratio of 3:7, implicating paracrine signaling. Signals identified included FGFs, VEGFs, EGFs, Wnts, and others, produced by associated stellate and endothelial cell precursors. Fifty-three, unique heparan sulfate (HS) oligosaccharides were synthesized, assessed for formation of high affinity complexes with paracrine signals, and each complex screened for biological activity(ies) on organoids. Ten distinct HS-oligosaccharides, all 10-12 mers or larger, and in specific paracrine signal complexes elicited particular biological responses. Of note, complexes of paracrine signals and 3-O sulfated HS-oligosaccharides elicited slowed growth, and with Wnt3a, elicited growth arrest of organoids for months. If future efforts are used to prepare HS-oligosaccharides resistant to breakdown in vivo, then [paracrine signal-HS-oligosaccharide] complexes are potential therapeutic agents for clinical treatments of FLCs, an exciting prospect for a deadly disease.

Dyrk2 gene transfer suppresses hepatocarcinogenesis by promoting the degradation of Myc and Hras.

Background & Aims: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has a poor prognosis. However, the molecular mechanisms underlying hepatocarcinogenesis and progression remain unknown. In vitro gain- and loss-of-function analyses in cell lines and xenografts revealed that dual-specificity tyrosine-regulated kinase 2 (DYRK2) influences tumour growth in HCC. Methods: To investigate the role of Dyrk2 during hepatocarcinogenesis, we developed liver-specific Dyrk2 conditional knockout mice and an in vivo gene delivery system with a hydrodynamic tail vein injection and the Sleeping Beauty transposon. The antitumour effects of Dyrk2 gene transfer were investigated in a murine autologous carcinogenesis model. Results: Dyrk2 expression was reduced in tumours, and that its downregulation was induced before hepatocarcinogenesis. Dyrk2 gene transfer significantly suppressed carcinogenesis. It also suppresses Myc-induced de-differentiation and metabolic reprogramming, which favours proliferative, and malignant potential by altering gene profiles. Dyrk2 overexpression caused Myc and Hras degradation at the protein level rather than at the mRNA level, and this degradation mechanism was regulated by the proteasome. Immunohistochemical analyses revealed a negative correlation between DYRK2 expression and MYC and longer survival in patients with HCC with high-DYRK2 and low-MYC expressions. Conclusions: Dyrk2 protects the liver from carcinogenesis by promoting Myc and Hras degradation. Our findings would pave the way for a novel therapeutic approach using DYRK2 gene transfer. Impact and Implications: Hepatocellular carcinoma (HCC) is one of the most common cancers, with a poor prognosis. Hence, identifying molecules that can become promising targets for therapies is essential to improve mortality. No studies have clarified the association between DYRK2 and carcinogenesis, although DYRK2 is involved in tumour growth in various cancer cells. This is the first study to show that Dyrk2 expression decreases during hepatocarcinogenesis and that Dyrk2 gene transfer is an attractive approach with tumour suppressive activity against HCC by suppressing Myc-mediated de-differentiation and metabolic reprogramming that favours proliferative and malignant potential via Myc and Hras degradation.

Extended-Synaptotagmin 1 Enhances Liver Cancer Progression Mediated by the Unconventional Secretion of Cytosolic Proteins.

Extended-synaptotagmin 1 (E-Syt1) is an endoplasmic reticulum membrane protein that is involved in cellular lipid transport. Our previous study identified E-Syt1 as a key factor for the unconventional protein secretion of cytoplasmic proteins in liver cancer, such as protein kinase C delta (PKCδ); however, it is unclear whether E-Syt1 is involved in tumorigenesis. Here, we showed that E-Syt1 contributes to the tumorigenic potential of liver cancer cells. E-Syt1 depletion significantly suppressed the proliferation of liver cancer cell lines. Database analysis revealed that E-Syt1 expression is a prognostic factor for hepatocellular carcinoma (HCC). Immunoblot analysis and cell-based extracellular HiBiT assays showed that E-Syt1 was required for the unconventional secretion of PKCδ in liver cancer cells. Furthermore, deficiency of E-Syt1 suppressed the activation of insulin-like growth factor 1 receptor (IGF1R) and extracellular-signal-related kinase 1/2 (Erk1/2), both of which are signaling pathways mediated by extracellular PKCδ. Three-dimensional sphere formation and xenograft model analysis revealed that E-Syt1 knockout significantly decreased tumorigenesis in liver cancer cells. These results provide evidence that E-Syt1 is critical for oncogenesis and is a therapeutic target for liver cancer.

Poor tolerability of lenvatinib in elderly patients ≥80 years old with hepatocellular carcinoma: A multicenter observational study.

INTRODUCTION: Management of elderly patients with cancer has become a global issue. We investigated the safety and tolerability of lenvatinib in hepatocellular carcinoma (HCC) patients ≥80 years old. METHODS: We retrospectively evaluated 61 HCC patients and divided them into 2 groups: an elderly group (n = 13, ≥80 years old) and a younger group (n = 48, <80 years old). We compared the adverse events (AEs), administration period, dose intensity, objective response, and progression-free survival (PFS) between the two groups. RESULTS: The discontinuation of lenvatinib due to AEs was more frequent in the elderly group (8/13, 61.5%) than in the younger group (10/48, 20.8%) (P = 0.0043). Fatigue and appetite loss accounted for half of the cases discontinued due to AEs in the elderly group. The elderly group had a significantly lower 8-week-delivered dose intensity/body surface area ratio (147.2) and 8-week-relative dose intensity (50.0%) than those in the younger group (267.4, 67%) (P = 0.003, 0.029). The objective response rate was significantly lower in the elderly group (15.4%) than in the younger group (61.5%) (P = 0.021). The PFS in the elderly group tended to be shorter than that in the younger group (P = 0.058, hazard ratio [HR] 1.98). The modified albumin-bilirubin (mALBI) grade (hepatic function) (HR, 2.60; P = 0.01) and objective response (HR, 0.41; P = 0.011) were independently associated with the PFS in the multivariate analysis. CONCLUSION: The management of AEs is crucial for adherence and maintaining the dose intensity of lenvatinib in elderly HCC patients.

Protein Kinase C Delta Is a Novel Biomarker for Hepatocellular Carcinoma.

Backgrounds and Aims: Hepatocellular carcinoma (HCC) is the most common cancer with a poor prognosis. Identification of an alternative biomarker that can detect early-stage and conventional tumor marker-negative HCC is urgently needed. We found that protein kinase C delta (PKCδ) is specifically secreted from HCC cell lines into extracellular space and contributes to tumor development and that its serum levels were elevated in HCC patients. This study aimed to assess the practical usefulness of serum PKCδ for detecting HCC in chronic liver disease (CLD) patients. Methods: Serum PKCδ levels in 313 CLD patients with and without HCC (n = 187 and 126, respectively) were measured using a sandwich enzyme-linked immunosorbent assay. The diagnostic performance of PKCδ for HCC was evaluated using the receiver operating characteristic curve analysis and was compared with that of conventional markers, α-fetoprotein (AFP), and des-γ-carboxy prothrombin (DCP). Results: Serum PKCδ levels in HCC patients were significantly higher than those in CLD patients without HCC. PKCδ distinguished HCC patients from CLD patients without HCC, with high sensitivity and specificity. Subgroup analyses revealed that the diagnostic performance of PKCδ for HCC was comparable to that of AFP and DCP, and that approximately 40% of AFP/DCP double-negative HCC patients were positive for PKCδ. PKCδ yielded better diagnostic performance for detecting solitary small-sized (ie, very early stage) HCC than AFP and DCP. There was no significant correlation between serum PKCδ and AFP/DCP levels. Conclusion: Serum PKCδ is a novel HCC biomarker, which is independent of and complementary to conventional markers. Specifically, PKCδ may be useful for detecting very early-stage or AFP/DCP double-negative HCC.

Safety and efficacy of pentazocine-midazolam combination for pain and anxiety relief in radiofrequency ablation therapy for hepatocellular carcinoma.

Background and Aim: Radiofrequency ablation (RFA) therapy is frequently used as first-line treatment for small hepatocellular carcinoma (HCC). RFA is often associated with pain; however, no definitive solution has been established for its relief. We retrospectively analyzed the safety and efficacy of the combination of pentazocine and midazolam to relieve pain experienced by HCC patients undergoing RFA. Methods: We studied 77 patients with 98 HCCs treated with RFA between January 2015 and August 2019. Patients were divided into two groups: the sedative-free group, which included those who received pentazocine alone, and the pentazocine-midazolam group, which included those who received a combination of pentazocine and midazolam. The degrees of analgesia and sedation were evaluated using the numerical rating scale (NRS) and the Richmond Agitation-Sedation Scale (RASS), respectively. Other parameters such as treatment time, awakening time, midazolam dosage, vital signs, local recurrence rate, and time to recurrence were also examined. Results: The median NRS score and RASS score were significantly lower in the pentazocine-midazolam group. Ninety-five percent of patients in the pentazocine-midazolam group had no memory of the RFA session. The treatment time and awakening time were prolonged for the pentazocine-midazolam group. No significant differences in oxygen saturation, recurrence rates, and time to local recurrence were observed between groups. Conclusion: A combination of pentazocine and midazolam is safe and effective for pain and anxiety relief experienced by patients undergoing RFA for local treatment of HCC.

Extended-synaptotagmin 1 engages in unconventional protein secretion mediated via SEC22B+ vesicle pathway in liver cancer.

Protein secretion in cancer cells defines tumor survival and progression by orchestrating the microenvironment. Studies suggest the occurrence of active secretion of cytosolic proteins in liver cancer and their involvement in tumorigenesis. Here, we investigated the identification of extended-synaptotagmin 1 (E-Syt1), an endoplasmic reticulum (ER)-bound protein, as a key mediator for cytosolic protein secretion at the ER-plasma membrane (PM) contact sites. Cytosolic proteins interacted with E-Syt1 on the ER, and then localized spatially inside SEC22B+ vesicles of liver cancer cells. Consequently, SEC22B on the vesicle tethered to the PM via Q-SNAREs (SNAP23, SNX3, and SNX4) for their secretion. Furthermore, inhibiting the interaction of protein kinase Cδ (PKCδ), a liver cancer-specific secretory cytosolic protein, with E-Syt1 by a PKCδ antibody, decreased in both PKCδ secretion and tumorigenicity. Results reveal the role of ER-PM contact sites in cytosolic protein secretion and provide a basis for ER-targeting therapy for liver cancer.

Centrilobular zonal necrosis is a unique subtype of autoimmune hepatitis: A cohort study.

BACKGROUNDS: Centrilobular zonal necrosis (CZN) is described as a histological feature present in a small number of autoimmune hepatitis (CZN-AIH) patients. CZN may be detected in the absence of significant interface hepatitis, which is the most important histological finding of AIH. The clinical and histopathological spectra of CZN-AIH were not homogeneous, and the concept of CZN-AIH as a distinctive subtype of AIH remains controversial, due to the rarity of CZN-AIH and the ambiguous definition of CZN. METHODS: To elucidate the clinical and immunogenetic features of CZN-AIH, a total of 102 biopsy samples of AIH, obtained at The Jikei University Katsushika Medical Center and Jikei University Hospital from 2000 to 2018, were reviewed. The 32 patients whose biopsies showed CZN were selected as the CZN-AIH group, and the remaining 70 were grouped as the non-CZN-AIH controls (control AIH). Data on clinical, histopathologic, and immunogenetic features were statistically compared between the CZN-AIH and the control AIH group. Additionally, the impact of the onset pattern (acute or chronic) and coexistent significant interface hepatitis in CZN-AIH was determined. RESULTS: In CZN-AIH, the frequency of acute-onset cases was significantly higher than that in control AIH (56.2% vs 32.9%; P < .05), and the number of cases with moderate-to-severe interface hepatitis in liver histology was significantly lower (37.5% vs 87.1%; P < .001). Compared to the control AIH, cases of CZN-AIH had lower immunoglobulin G level (P < .001), lower antinuclear antibodies titer (P < .001), and lower AIH score (P < .001). The immunogenetic disproportionate distribution of HLA-DR phenotypes in control AIH (increased HLA-DR4 and decreased HLA-DR9) was not found in CZN-AIH. Moreover, CZN-AIH was less frequently relapsed (P < .05). For the acute-onset CZN-AIH cases, the clinical features were hardly indistinguishable from the chronic CZN-AIH cases. Similarly, the existence of interface hepatitis did not influence on the pathophysiology of CZN-AIH. Moreover, the acute-onset CZN-AIH cases is clinically distinguishable from acute-onset control AIH. CONCLUSION: CZN can characterize as a distinct AIH subtype, regardless of onset-pattern or coexistence of significant interface hepatitis. To further strengthen this hypothesis, collection of more CZN-AIH cases is needed.

Extracellular PKCδ signals to epidermal growth factor receptor for tumor proliferation in liver cancer cells.

Protein kinase C delta (PKCδ) is a multifunctional PKC family member and has been implicated in many types of cancers, including liver cancer. Recently, we have reported that PKCδ is secreted from liver cancer cells, and involved in cell proliferation and tumor growth. However, it remains unclear whether the extracellular PKCδ directly regulates cell surface growth factor receptors. Here, we identify epidermal growth factor receptor (EGFR) as a novel interacting protein of the cell surface PKCδ in liver cancer cells. Imaging studies showed that secreted PKCδ interacted with EGFR-expressing cells in both autocrine and paracrine manners. Biochemical analysis revealed that PKCδ bound to the extracellular domain of EGFR. We further found that a part of the amino acid sequence on the C-terminal region of PKCδ was similar to the putative EGFR binding site of EGF. In this regard, the point mutant of PKCδ in the binding site lacked the ability to bind to the extracellular domain of EGFR. Upon an extracellular PKCδ-EGFR association, ERK1/2 activation, downstream of EGFR signaling, was apparently induced in liver cancer cells. This study indicates that extracellular PKCδ behaves as a growth factor and provides a molecular basis for extracellular PKCδ-targeting therapy for liver cancer.

The Geriatric Nutritional Risk Index Predicts Tolerability of Lenvatinib in Patients With Hepatocellular Carcinoma.

BACKGROUND/AIM: We aimed to investigate the association between The Geriatric Nutritional Risk Index (GNRI) and the tolerability of lenvatinib in patients with hepatocellular carcinoma (HCC). PATIENTS AND METHODS: We retrospectively evaluated 61 HCC patients treated with lenvatinib and compared those with low GNRI (≤98, n=26) to those with high GNRI (>98, n=35). RESULTS: The discontinuation of lenvatinib due to adverse events was more frequent in the low GNRI group (46.2%) than in the high GNRI group (17.1%) (p=0.014). Multivariate analysis revealed that low GNRI (p=0.014), hypothyroidism (model 1 p=0.021, model 2 p=0.013), and advanced age (p=0.026) were independently associated with the discontinuation of lenvatinib. The progression-free survival in the low GNRI group was significantly shorter than that in the high GNRI group (p=0.047). CONCLUSION: The GNRI might be independently associated with the tolerability of lenvatinib in patients with HCC.

The Impact of Cirrhosis and History of Hepatocellular Carcinoma on All-Cause Mortality After Eradication of Hepatitis C Virus in Patients With Chronic Hepatitis C.

Backgrounds and Aims: Cirrhosis and hepatocellular carcinoma (HCC) are potentially fatal complications of chronic hepatitis C virus (HCV) infection. We investigated how compensated cirrhosis and a history of curatively treated HCC influenced patient mortality after HCV eradication, that is, sustained virologic response (SVR). Methods: We studied 5458 patients with confirmed SVR who were prospectively followed up for more than 1 year after SVR achieved with direct-acting antivirals. Mortality and the incidence of HCC development after SVR were analyzed based on the presence or absence of compensated cirrhosis or a history of curatively treated HCC before the start of therapy. Results: Mortality and the incidence of post-SVR HCC were significantly higher in patients with compensated cirrhosis and those with a history of curatively treated HCC than in those without these complications. Multivariate analysis showed that a history of HCC was associated with high mortality after SVR. In patients with no history of HCC, cirrhosis was associated with high mortality. Although both liver-related and nonliver-related mortality rates were significantly higher in patients with a history of HCC or cirrhosis, nonliver-related mortality did not differ based on HCC history, and liver-related and nonliver-related mortality were comparable regardless of cirrhosis after propensity score matching with age, gender, alcohol intake, and comorbidities. Conclusion: Mortality after SVR was significantly higher in patients with compensated cirrhosis or a history of HCC. While a history of HCC significantly increased mortality after SVR, even following curative treatment, the impact of pre-SVR compensated cirrhosis on post-SVR mortality was modest.

A MicroRNA-Based Network Provides Potential Predictive Signatures and Reveals the Crucial Role of PI3K/AKT Signaling for Hepatic Lineage Maturation.

BACKGROUND: Functions of miRNAs involved in tumorigenesis are well reported, yet, their roles in normal cell lineage commitment remain ambiguous. Here, we investigated a specific "transcription factor (TF)-miRNA-Target" regulatory network during the lineage maturation of biliary tree stem cells (BTSCs) into adult hepatocytes (hAHeps). METHOD: Bioinformatic analysis was conducted based on our RNA-seq and microRNA-seq datasets with four human hepatic-lineage cell lines, including hBTSCs, hepatic stem cells (hHpSCs), hepatoblasts (hHBs), and hAHeps. Short time-series expression miner (STEM) analysis was performed to reveal the time-dependent dynamically changed miRNAs and mRNAs. GO and KEGG analyses were applied to reveal the potential function of key miRNAs and mRNAs. Then, the miRDB, miRTarBase, TargetScan, miRWalk, and DIANA-microT-CDS databases were adopted to predict the potential targets of miRNAs while the TransmiR v2.0 database was used to obtain the experimentally supported TFs that regulate miRNAs. The TCGA, Kaplan-Meier Plotter, and human protein atlas (HPA) databases and more than 10 sequencing data, including bulk RNA-seq, microRNA-seq, and scRNA-seq data related to hepatic development or lineage reprogramming, were obtained from both our or other published studies for validation. RESULTS: STEM analysis showed that during the maturation from hBTSCs to hAHeps, 52 miRNAs were downwardly expressed and 928 mRNA were upwardly expressed. Enrichment analyses revealed that those 52 miRNAs acted as pluripotency regulators for stem cells and participated in various novel signaling pathways, including PI3K/AKT, MAPK, and etc., while 928 mRNAs played important roles in liver-functional metabolism. With an extensive sorting of those key miRNAs and mRNAs based on the target prediction results, 23 genes were obtained which not only functioned as the targets of 17 miRNAs but were considered critical for the hepatic lineage commitment. A "TF-miRNA-Target" regulatory network for hepatic lineage commitment was therefore established and had been well validated by various datasets. The network revealed that the PI3K/AKT pathway was gradually suppressed during the hepatic commitment. CONCLUSION: A total of 17 miRNAs act as suppressors during hepatic maturation mainly by regulating 23 targets and modulating the PI3K/AKT signaling pathway. The regulatory network uncovers possible signatures and guidelines enabling us to identify or obtain the functional hepatocytes for future study.

Unconventional Secretion of PKCδ Exerts Tumorigenic Function via Stimulation of ERK1/2 Signaling in Liver Cancer.

Expression of human protein kinase C delta (PKCδ) protein has been linked to many types of cancers. PKCδ is known to be a multifunctional PKC family member and has been rigorously studied as an intracellular signaling molecule. Here we show that PKCδ is a secretory protein that regulates cell growth of liver cancer. Full-length PKCδ was secreted to the extracellular space in living liver cancer cells under normal cell culture conditions and in xenograft mouse models. Patients with liver cancer showed higher levels of serum PKCδ than patients with chronic hepatitis or liver cirrhosis or healthy individuals. In liver cancer cells, PKCδ secretion was executed in an endoplasmic reticulum (ER)-Golgi-independent manner, and the inactivation status of cytosolic PKCδ was required for its secretion. Furthermore, colocalization studies showed that extracellular PKCδ was anchored on the cell surface of liver cancer cells via association with glypican 3, a liver cancer-related heparan sulfate proteoglycan. Addition of exogenous PKCδ activated IGF-1 receptor (IGF1R) activation and subsequently enhanced activation of ERK1/2, which led to accelerated cell growth in liver cancer cells. Conversely, treatment with anti-PKCδ antibody attenuated activation of both IGF1R and ERK1/2 and reduced cell proliferation and spheroid formation of liver cancer cells and tumor growth in xenograft mouse models. This study demonstrates the presence of PKCδ at the extracellular space and the function of PKCδ as a growth factor and provides a rationale for the extracellular PKCδ-targeting therapy of liver cancer. SIGNIFICANCE: PKCδ secretion from liver cancer cells behaves as a humoral growth factor that contributes to cell growth via activation of proliferative signaling molecules, which may be potential diagnostic or therapeutic targets.

Recent Insights Into the Multiple Pathways Driving Non-alcoholic Steatohepatitis-Derived Hepatocellular Carcinoma.

The incidence of metabolic syndrome with fatty liver is spreading on a worldwide scale. Correspondingly, the number of patients with the hepatic phenotype of metabolic syndrome, non-alcoholic fatty liver disease (NAFLD), and in its advanced states, non-alcoholic steatohepatitis (NASH), and the subsequent hepatocellular carcinoma (HCC) derived from NASH (NASH-HCC) is increasing remarkably. A large-scale epidemiological study revealed that obesity can be a risk factor of such cancers as HCC. Moreover, despite the ongoing trends of declining cancer incidence and mortality for most cancer types, HCC has experienced a markedly increased rate of both. Considering the differences in liver-related mortality among NAFLD patients, NASH, and NASH-HCC should be included in the objectives of initiatives to manage NAFLD patients and their progression to the advanced stages. Unfortunately, research has yet to make a crucial drug discovery for the effective treatment of NASH and NASH-HCC, although it is urgently needed. The latest widespread concept of the "multiple parallel hits hypothesis," whereby multiple factors contribute concurrently to disease pathogenesis has led to advances in the elucidation of hepatic and systemic molecular mechanisms driving NASH and the subsequent NASH-HCC progression; the results are not only extensive but promising for therapeutics. Here, we have summarized the myriad landmark discoveries of recent research into the pathogenic processes underlying NASH-HCC development and with the greatest possibility for a new generation of pharmaceutical products for interference and treatment.

Histological and biochemical evaluation of transforming growth factor-ß activation and its clinical significance in patients with chronic liver disease.

Transforming growth factor-ß (TGF-ß) is a key driver for liver fibrogenesis. TGF-ß must be activated in order to function. Plasma kallikrein (PLK) is a TGF-ß activator that cleaves the latency-associated protein (LAP) between arginine58 and lysine59 residues and releases active TGF-ß from the latent TGF-ß-LAP complex. Thus, the generation of two LAP degradation products, ending at arginine58 (R58/LAP-DPs) and beginning from lysine59 (L59/LAP-DPs), reflects PLK-dependent TGF-ß activation. However, the significance and details of TGF-ß activation in patients with chronic liver disease (CLD) remain uncertain. We herein examined the PLK-dependent TGF-ß activation in patients by detecting R58 and L59/LAP-DPs. A total of 234 patients with CLD were included in this study. Liver biopsy specimens were used for immunostaining to detect R58/LAP-DPs, while plasma samples were subjected to an enzyme-linked immunosorbent assay to measure the L59/LAP-DP concentration. R58/LAP-DP was robustly expressed in and around the sinusoidal cells before the development of the fibrous regions. The R58/LAP-DP expression at fibrosis stage 1 was higher than at any other stages, and the relationship between the plasma L59/LAP-DP level and the stage of fibrosis also showed a similar trend. The abundance of plasma L59/LAP-DP showed no correlation with the levels of direct serum biomarkers of liver fibrosis; however, its changes during interferon-based therapy for chronic hepatitis C were significantly associated with virological responses. Our results suggest that PLK-dependent TGF-ß activation occurs in the early stages of fibrosis and that its unique surrogate markers, R58 and L59/LAP-DPs, are useful for monitoring the clinical course of CLD.

Forced expression of DYRK2 exerts anti-tumor effects via apoptotic induction in liver cancer.

Liver cancer is highly aggressive and globally exhibits a poor prognosis. Therefore, the identification of novel molecules that can become targets for future therapies is urgently required. We have reported that dual-specificity tyrosine-regulated kinase 2 (DYRK2) functions as a tumor suppressor by regulating cell survival, differentiation, proliferation and apoptosis. However, the research into its clinical application as a molecular target has remained to be explored. Here we showed that DYRK2 knockdown enhanced tumor growth of liver cancer cells. Conversely and more importantly, adenovirus-mediated overexpression of DYRK2 resulted in inhibition of cell proliferation and tumor growth, and induction of apoptosis both in vitro and in vivo. Furthermore, we found that liver cancer patients with low DYRK2 expression had a significantly shorter overall survival. Given the findings that DYRK2 regulates proliferation and apoptosis of cancer cells, DYRK2 expression could be a promising predictive marker of the prognosis in liver cancer. Stabilized or forced expression of DYRK2 may become thus a potential target for novel gene therapy against liver cancer.

Mouse models for investigating the underlying mechanisms of nonalcoholic steatohepatitis-derived hepatocellular carcinoma.

As the incidence of hepatocellular carcinoma (HCC) caused by infection with the hepatotropic viruses hepatitis B and hepatitis C decreases, greater attention has become focused on HCC caused by nonalcoholic steatohepatitis (NASH), an advanced form of nonalcoholic fatty liver disease which has shown increasing prevalence in correspondence with the overall increase in metabolic syndrome over the recent decades. Several clinical population studies have shown a positive relationship between NASH and HCC, while also providing initial insights into the underlying mechanisms of HCC development from NASH. Research into the pathological progression of NASH to HCC has advanced by use of several beneficial rodent models. In this review, we summarize the established mouse models for preclinical research of NASH-associated HCC and discuss the underlying hepatic mechanisms of NASH-related tumorigenesis identified to date that could lead to new targets for treatment and prevention.