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The RAS-BRAF signaling is a major pathway of cell proliferation and their mutations are frequently found in human cancers. Adenylate kinase 2 (AK2), which modulates balance of adenine nucleotide pool, has been implicated in cell death and cell proliferation independently of its enzyme activity. Recently, the role of AK2 in tumorigenesis was in part elucidated in some cancer types including lung adenocarcinoma and breast cancer, but the underlying mechanism is not clear. Here, we show that AK2 is a BRAF-suppressor. In in vitro assays and cell model, AK2 interacted with BRAF and inhibited BRAF activity and downstream ERK phosphorylation. Energy-deprived conditions in cell model and the addition of AMP to cell lysates strengthened the AK2-BRAF interaction, suggesting that AK2 is involved in the regulation of BRAF activity in response to cell metabolic state. AMP facilitated the AK2-BRAF complex formation through binding to AK2. In a panel of HCC cell lines, AK2 expression was inversely correlated with ERK/MAPK activation, and AK2-knockdown or -knockout increased BRAF activity and promoted cell proliferation. Tumors from HCC patients showed low-AK2 protein expression and increased ERK activation compared to non-tumor tissues and the downregulation of AK2 was also verified by two microarray datasets (TCGA-LIHC and GSE14520). Moreover, AK2/BRAF interaction was abrogated by RAS activation in in vitro assay and cell model and in a mouse model of HRAS G12V -driven HCC, and AK2 ablation promoted tumor growth and BRAF activity. AK2 also bound to BRAF inhibitor-insensitive BRAF mutants and attenuated their activities. These findings indicate that AK2 monitoring cellular AMP levels is indeed a negative regulator of BRAF, linking the metabolic status to tumor growth., (© 2022. The Author(s).)

Increased fatty acid (FA) is often observed in highly proliferative tumors. FAs have been shown to modulate the secretion of proteins from tumor cells, contributing to tumor survival. However, the secreted factors affected by FA have not been systematically explored. Here, we found that treatment of oleate, a monounsaturated omega-9 FA, promoted the proliferation of HepG2 cells. To examine the secreted factors associated with oleate-induced cell proliferation, we performed a comprehensive secretome profiling of oleate-treated and untreated HepG2 cells. A comparison of the secretomes identified 349 differentially secreted proteins (DSPs; 145 upregulated and 192 downregulated) in oleate-treated samples, compared to untreated samples. The functional enrichment and network analyses of the DSPs revealed that the 145 upregulated secreted proteins by oleate treatment were mainly associated with cell proliferation-related processes, such as lipid metabolism, inflammatory response, and ER stress. Based on the network models of the DSPs, we selected six DSPs (MIF, THBS1, PDIA3, APOA1, FASN, and EEF2) that can represent such processes related to cell proliferation. Thus, our results provided a secretome profile indicative of an oleate-induced proliferation of HepG2 cells.

Hepatocellular carcinoma (HCC), a representative example of a malignancy with a poor prognosis, is characterized by high mortality because it is typically in an advanced stage at diagnosis and leaves very little hepatic functional reserve. Despite advances in medical and surgical techniques, there is no omnipotent tool that can diagnose HCC early and then cure it medically or surgically. Several recent studies have shown that a variety of pathways are involved in the development, growth, and even metastasis of HCC. Among a variety of cytokines or molecules, some investigators have suggested that arrest-defective 1 (ARD1), an acetyltransferase, plays a key role in the development of malignancies. Although ARD1 is thought to be centrally involved in the cell cycle, cell migration, apoptosis, differentiation, and proliferation, the role of ARD1 and its potential mechanistic involvement in HCC remain unclear. Here, we review the present literature on ARD1. First, we provide an overview of the essential structure, functions, and molecular mechanisms or pathways of ARD1 in HCC. Next, we discuss potential clinical implications and perspectives. We hope that, by providing new insights into ARD1, this review will help to guide the next steps in the development of markers for the early detection and prognosis of HCC.

Aim: We investigated the therapeutic effects of a mitogen-activated protein (MEK) inhibitor, selumetinib, in a hepatic melanoma metastasis model and studied its possible mechanism of action., Materials and Methods: Melanoma cell lines were exposed to selumetinib under different experimental conditions. We established a mouse model of liver metastasis and treated mice orally with vehicle or selumetinib and then evaluated metastasis progress., Results: Growth inhibition was observed in melanoma cells as a consequence of G 1 -phase cell-cycle arrest and the subsequent induction of apoptosis in a dose- and time-dependent manner. Mice with established liver metastases that were treated with selumetinib exhibited significantly less tumor progression than vehicle-treated mice. c-Myc expression in metastasized liver tissues were suppressed by selumetinib. Moreover, oral treatment with selumetinib modulated expression of epithelial-to-mesenchymal transition- and metastasis-related genes, including integrin alpha-5 (ITGA5), jagged 1 (JAG1), zinc finger E-box-binding homeobox 1 (ZEB1), NOTCH, and serpin peptidase inhibitor clade E (SERPINE1)., Conclusion: We established a mouse model of hepatic metastasis using a human melanoma cell line, such models are essential in elucidating the therapeutic effects of anti-metastatic drugs. Our data suggest the possibility that selumetinib presents a new strategy to treat liver metastasis in patients with melanoma by suppressing epithelial-to-mesenchymal transition-related genes., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Aim: To determine the genomic changes in hepatitis B virus (HBV) and evaluate their role in the development of hepatocellular carcinoma (HCC) in patients chronically infected with genotype C HBV., Methods: Two hundred and forty chronic hepatitis B (CHB) patients were subjected and followed for a median of 105 mo. HCC was diagnosed in accordance with AASLD guidelines. The whole X, S, basal core promoter (BCP), and precore regions of HBV were sequenced using the direct sequencing method., Results: All of the subjects were infected with genotype C HBV. Out of 240 CHB patients, 25 (10%) had C1653T and 33 (14%) had T1753V mutation in X region; 157 (65%) had A1762T/G1764A mutations in BCP region, 50 (21%) had G1896A mutation in precore region and 67 (28%) had pre-S deletions. HCC occurred in 6 patients (3%). The prevalence of T1753V mutation was significantly higher in patients who developed HCC than in those without HCC. The cumulative occurrence rates of HCC were 5% and 19% at 10 and 15 years, respectively, in patients with T1753V mutant, which were significantly higher than 1% and 1% in those with wild type HBV (P < 0.001)., Conclusion: The presence of T1753V mutation in HBV X-gene significantly increases the risk of HCC development in patients chronically infected with genotype C HBV.

Goal and Background: Host genetic diversity may play roles in development of HCC. This study was conducted to validate the effects of tumor necrosis factor-alpha (TNF-α) gene polymorphism on development of hepatocellular carcinoma (HCC) in patients chronically infected with hepatitis B virus (HBV)., Study: The study cohort comprised 224 patients with HBV-associated HCC and 206 with HBV-associated liver cirrhosis (LC). Using chromosomal DNA, TNF-α promoter gene polymorphisms were determined at 3 common single-nucleotide polymorphism (SNP) sites (TNF-α-1031 T>C, TNF-α-857 C>T, and TNF-α-308 G>A) using a single base extension method. The genotype distributions were compared between the 2 groups. All the HBV-associated LC patients were followed up regularly every 6 to 12 months for surveillance of HCC development., Results: In the cross-sectional analysis, the frequency of TNF-α-857 T allele was much higher in patients with HCC compared with those with LC (42% vs. 31%, P<0.01). Of 206 HBV-associated LC patients, 12 (5.8%) developed HCC during the median follow-up period of 36 months. The cumulative occurrence rates of HCC were significantly higher in patients with TNF-α-857 T allele than those withTNF-α-857 C/C genotype (1-, 3-, and 5-y rates: 2.9%, 12.8%, and 20.7% vs. 0%, 3.1%, and 5.3%, respectively; P=0.013). However, the other genetic polymorphisms of TNF-α promoter gene did not affect the development of HCC. In multivariate analysis, TNF-α-857 T allele was a significant predictor of HCC development (hazard ratio 6.29, P=0.01)., Conclusion: Our data suggest that TNF-α-857 T allele is closely associated with development of HCC in HBV-associated LC patients.

Hepatocellular carcinoma (HCC), a prototype of hypervascular tumors, is one of the most common malignancies in the world, especially hyperendemic in the Far East where chronic hepatitis B virus (HBV) infection is highly prevalent. It is characterized by the clinical feature of a poor prognosis or a high mortality due to its already far advanced stages at diagnosis. It is so multifactorial that hepatocarcinogenesis cannot be explained by a single molecular mechanism. To date, a number of pathways have been known to contribute to the development, growth, angiogenesis, and even metastasis of HCC. Among the various factors, metastatic tumor antigens (MTAs) or metastasis-associated proteins have been vigorously investigated as an intriguing target in the field of hepatocarcinogenesis. According to recent studies including ours, MTAs are not only involved in the HCC development and growth (molecular carcinogenesis), but also closely associated with the post-operative recurrence and a poor prognosis or a worse response to post-operative anti-cancer therapy (clinical significance). Herein, we review MTAs in light of their essential structure, functions, and molecular mechanism in hepatocarcinogenesis. We will also focus in detail on the interaction between hepatitis B x protein (HBx) of HBV and MTA in order to clarify the HBV-associated HCC development. Finally, we will discuss the prognostic significance and clinical application of MTA in HCC. We believe that this review will help clinicians to understand the meaning and use of the detection of MTA in order to more effectively manage their HCC patients.

Background: Metastatic tumor antigen 1 (MTA1) overexpression is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). It has been suggested that pegylated interferon (Peg-IFN) can prevent the occurrence of HCC in patients who have chronic viral hepatitis. In this study, the authors examined whether postoperative adjuvant Peg-IFN therapy can reduce the recurrence of MTA1-positive HCC after curative surgical resection., Methods: In this case-control study, 93 patients with MTA1-positive HCC who underwent curative surgical resection were prospectively enrolled. The median patient age was 53 years (range, 27-78); there were 65 men and 28 women; the etiology was hepatitis B virus (HBV) in 77 patients, hepatitis C virus (HCV) in 6 patients, and non-HBV/non-HCV in 10 patients; 31 patients received Peg-IFN (Peg-INTRON) subcutaneously at a dose of 50 μg per week for 12 months (the Peg-IFN group); and the remaining 62 patients were followed only and did not receive any adjuvant therapies (control group). Patients were followed every 1 to 3 months for a median of 24 months., Results: HCC recurred postoperatively in 26 of 93 patients (28%), and 9 patients (10%) died during follow-up. The overall cumulative recurrence rates were significantly lower in the Peg-IFN group than in the control group (7% and 14% vs. 24% and 34% at 1 year and 2 years, respectively; P < .05). In addition, the 1-year and 2-year cumulative survival rates were higher in the Peg-IFN group compared with the control group (100% vs. 93% and 100% vs. 87%, respectively; P < .05). In multivariate analysis, the receipt of adjuvant Peg-IFN therapy, in addition to having a lower Cancer of the Liver Italian Program score and being a woman, was an independent, favorable factor for a lower risk of postoperative recurrence., Conclusions: The current data indicate that adjuvant Peg-IFN therapy may reduce the recurrence of HCC in patients who have MTA1-positive HCC after curative surgical resection., (Copyright © 2013 American Cancer Society.)

Background/aim: Overexpression of metastatic tumor antigen-1 (MTA-1) is suggested to be associated with frequent postoperative recurrence and poor survival of hepatocellular carcinoma (HCC) patients. In this study, we intended to determine clinical factors predisposing the overexpression of MTA-1 in patients with hepatitis B virus (HBV)-associated HCC and also examine whether MTA-1 overexpression affects the survival periods of these patients treated with curative surgical resection., Methods: A total of 303 patients with HBV-associated HCC who underwent curative surgical resection were subjected. The expressions of MTA-1 in HCC and surrounding non-tumor liver tissues were evaluated using the immunohistochemical method. The clinical, radiological and histological characteristics of the patients were analyzed in relation to the expression of MTA-1 to find predisposing factors of MTA-1 overexpression., Results: MTA-1 was overexpressed in 104 HCC tissues (34.3 %) and none of the surrounding non-tumor tissues. Clinically, MTA-1 overexpression was significantly associated with younger age, female gender, higher serum alpha-fetoprotein level, and Child-Turcotte-Pugh class A. Also, portal vein thrombosis, microvascular invasion, capsular invasion and poorly histological differentiation were associated with overexpression of MTA-1. The cumulative survival rates were significantly lower in patients with MTA-1 overexpression compared with those in the MTA-1 negative group (P = 0.03). In addition to the overexpression of MTA-1, the presence of microvascular or capsular invasion was a significant factor determining the poor survival of the patients with HBV-associated HCC after curative resection., Conclusions: MTA-1 is overexpressed in patients with HBV-associated HCC of invasive nature. MTA-1 overexpression is associated with shorter survival periods of patients with HBV-associated HCC after curative resection.

Background and Aim: Metastasis is a multistep event in which neoplastic cells detach from the tumor, migrate, disseminate, extravasate, and eventually proliferate at the secondary distant sites. Hepatocellular carcinoma (HCC) is characterized by hypervascularity and frequent metastasis. Recently, metastasis-associated proteins were identified and named metastatic tumor antigens (MTA) 1, 2, and 3. They have been found to be contained in the nucleosome remodeling and histone deacetylase complex. MTA2 has been reported to interact with p53 and inhibit p53-mediated cell growth arrest and apoptosis by deacetylation. Although it has been reported that the expression of MTA1 is related to tumor progression and metastasis, it is still unclear how MTA2 is involved in HCC. In this study, we found that the overexpression of MTA2 is associated with HCC size and differentiation after hepatectomy., Methods: The expression of MTA2 was examined in 506 human HCC samples that underwent hepatic resection using tissue microarray. The expression of MTA2 was classified into 0, 1, 2, and 3, based on immunoreactivity., Results: The expression of MTA2 was predominantly localized to the nucleus. MTA2 was detected in 487 (96.2%) of the 506 human HCC samples. Notably, the MTA2 expression level strongly increased depending on the size and differentiation of HCC., Conclusions: These findings indicate a tight correlation between the MTA2 expression level and HCC size and differentiation. Therefore, MTA2 might be a predictor of aggressive phenotypes and a possible target molecule for anticancer drug design in human HCC.

Metastatic tumor antigen 1 (MTA1) is known to play a role in angiogenic processes as a stabilizer of hypoxia-inducible factor 1-alpha (HIF1-alpha). In this study, we examined whether overexpression of MTA1 affects the recurrence of hepatocellular carcinoma (HCC) after surgical resection and the survival of the patients. A total of 506 HCC patients who underwent hepatic resection were included in the study. They were followed up for a median of 43 months (range, 1-96 months) after hepatectomy. MTA1 expression levels were determined by the proportion of immunopositive cells (none, all negative; +, <50%; ++, >50%). The relationships between MTA1 expression and the HCC histological features, the appearance of recurrent HCC after surgical resection, and the survival of the patients were examined. Eighty-eight cases (17%) of the HCCs were positive for MTA1, although the surrounding liver tissues were all negative for MTA1; 62 cases were + and 26 cases were ++. Increased MTA1 expression levels in HCC were correlated with larger tumors (P = 0.04), perinodal extension (P = 0.03), and microvascular invasion (P = 0.008). Histological differentiation had marginal significance (P = 0.056). However, there was no association between MTA1 expression and age, sex, Child-Pugh class, and capsule invasion of HCC. Interestingly, MTA1 expression levels were significantly greater in hepatitis B virus (HBV)-associated HCC compared with hepatitis C virus (HCV)-associated HCC (P = 0.017). The cumulative recurrence rates of MTA1-positive HCCs were markedly greater than those of MTA1-negative HCCs (P < 0.0001). The cumulative survival rates of patients with MTA1-positive HCCs were significantly shorter than those of patients with MTA1-negative HCCs (P < 0.0001). In conclusion, our data indicate that MTA1 is closely associated with microvascular invasion, frequent postoperative recurrence, and poor survival of HCC patients, especially in those with HBV-associated HCC.

Leiomyosarcoma is a rare tumor of the liver. It usually arises from many other organs including uterus, gastrointestinal tract, retroperitoneum, and soft tissues. Primary hepatic leiomyosarcoma progresses very slowly and is not associated with chronic liver disease. When the tumor is detected early enough to be treated by operation, the prognosis is favorable. While several cases of primary hepatic leiomyosarcoma have been reported in Korea, there was no case associated with acute bleeding. We report a 80-year old male patient with huge primary hepatic leiomyosarcoma, who presented with acute bleeding and IVC obstruction. The patient was treated by embolization and IVC stenting.

Backgrounds/aims: The prognosis of cirrhotic patients with hepatocellular carcinoma (HCC) depends on both residual liver function and tumor characteristics. The aims of this study was to construct a new prognostic index for HCC patients: the modified CLIP score, and to compare its discriminatory ability and predictive power with those of the CLIP score that is currently the most commonly used integrated staging score in patients of HCC., Methods: A retrospective analysis of 237 cases of HCC diagnosed at Dong-A university hospital was performed. Prognostic analysis was performed for single variables by estimating survival distributions with the Kaplan-Meier's method, and statistically compared by the log-rank test., Results: Patients had a mean age of 57.5 years and were predominantly males (79.7%). The overall median survival period was 25.7 months. It was correlated to ascites, portal vein thrombosis, AFP, tumor size, and Child-Pugh classification. The median survival period was 41.0, 25.2, 13.8, 13.4, and 6.5 months for CLIP scores 0, 1, 2, 3, and 4 to 6, respectively (P<0.001), and 42.1, 34.0, 25.7, 14.0, and 6.8 months for modified CLIP scores 0, 1, 2, 3, and 4 to 6, respectively (P<0.001). The Kaplan-Meier's curve showed that the modified CLIP score had additional explanatory power above that of the CLIP score., Conclusions: The modified CLIP score, compared with the CLIP score, particularly in the score 2- to 3- patient groups of HCC, had greater discriminant ability and survival predictive power, but was not able to discriminate 4- to 6- patient group.

Background/aims: There are several staging systems to decide the stage of hepatocellular carcinoma (HCC), but yet incomplete. Okuda stage which includes both tumor characteristics and liver function is widely used. The aims of this study were to assess the usefulness of known prognostic factors and Okuda staging system in 237 cases of HCC., Methods: A retrospective analysis of 237 cases of HCC diagnosed from 2000 to 2002 was performed. We analyzed prognostic factors such as age, sex, liver cirrhosis, Child-Pugh classification, tumor size, albumin, bilirubin, alpha-FP, ascites, encephalopathy and Okuda stage. Prognostic analysis was performed for single variables and estimating survival distributions were analyzed by the Kaplan-Meier method, statistically compared by the log-rank test., Results: Patients had a mean age of 57.5 years and were predominantly men (79.7%). Liver cirrhosis were noticed in 214 cases (90.3%). The overall median survival period was 25.7 months. The median survival period was correlated to bilirubin, ascites, alpha-FP, tumor size, and Child-Pugh classification, but not to age, sex, and pattern of viral infection. The median survival period of the Okuda stage I, II and III cases was 35.8, 11.9 and 8.5 months (p<0.001)., Conclusions: The median survival period of patients with HCC is significantly correlated to Okuda staging system, and survival period has improved than the initial data when the Okuda staging system was published in 1985. However, in order to discriminate early staged HCC more accurately, other prognostic factors such as alpha-FP and tumor morphology should be included in future staging system for HCC.

Primary small cell carcinoma of the liver is an extremely rare tumor. Extrapulmonary small cell carcinoma shares many features of pulmonary small cell carcinoma, including the histological appearance, the aggressive clinical behavior and the frequent short-lasting response to either chemotherapy or radiotherapy. We experienced a 56-year-old man with small cell carcinoma that arose in the liver. Abdominal CT scan showed an 8 cm size, low density mass in the segment 4 of the liver and also multiple lymphadenopathies. Chest X-ray showed no abnormal finding, but the chest CT showed a right lower paratracheal lymphadenopathy. The pathological findings showed nests of small round cells with fine granular chromatin, inconspicuous nucleoli and scanty cytoplasm. Distinct and strong immunoreactions were seen for CD56 and c-kit, and sparse immunoreaction was seen for synaptophysin. Thyroid transcription factor-1 showed no immunoreaction. The tumor did not decrease in size despite chemotherapy. We report this case along with a review of the relevant literatures.

Objective: Budd-Chiari syndrome (BCS) is a known risk factor for hepatocellular carcinoma (HCC). Considering the pathophysiological mechanism of BCS, BCS-associated HCC may have a different carcinogenic process to hepatitis B virus (HBV)-associated HCC, resulting in different characteristic clinical features., Methods: The clinical, radiological and histopathological characteristics of 15 HCCs associated with BCS were analysed and compared with 211 HBV-associated HCCs., Results: HCC associated with BCS showed a female predominance in contrast to a male predominance in HCC associated with HBV infection. Child classes of BCS-associated HCC patients were not different from the classes of HBV-associated HCC. BCS tended to be associated with the single nodular type of HCC. Only one BCS-associated HCC patient had portal vein invasion at the time of diagnosis, compared with 96 patients with HBV-associated HCC. No HCC patients with BCS showed biliary invasion, compared with 47 HBV-associated HCC patients. The median survival period of HCC patients associated with BCS was 58 months, which was much longer than the median survival period of 10 months in HBV-associated HCC. All of the three BCS-associated HCCs available for histological examination were well differentiated., Conclusions: Patients with HCC associated with BCS seemed to survive for much longer periods than those with HBV due to the low invasiveness of the tumour. Such unique clinical features may be evidence of different carcinogenic processes in BCS-associated and HBV-associated HCC.

Background/aims: Tamoxifen has been tried in patients with hepatocellular carcinoma (HCC), however, its inhibitory mechanism remains unknown. In this study, we evaluated the effects of tamoxifen on HCC cell growth and the expression of transforming growth factor-beta1 (TGF-beta1) which had been known as an important cytokine in growth of HCC., Methods: Hep 3B cells were cultivated in estrogen free media with 0.1 micro M, 0.5 micro M, 1 micro M, 5 micro M, and 10 micro M of tamoxifen for 6 days. Viable cells were counted daily and the TGF-beta1 concentrations in supernatant were measured by ELISA method., Results: The number of viable HCC cells increased rather significantly after the treatment of tamoxifen of lower concentration (0.1micro M) compared with that of the control (2.59x10(7) vs. 1.97x107; p<0.05). As the concentration of treated tamoxifen was higher, the number of viable HCC cells became gradually less, resulting in the significant decrease of it at the highest concentration (10micro M) compared with that of the control (1.40x10(7) vs. 1.97x10(7); p<0.05). TGF-beta1 concentration in supernatant of tamoxifen-treated samples was significantly decreased compared with those of controls, regardless of the amount of treated tamoxifen., Conclusions: These results suggest that tamoxifen may suppress TGF-beta1 expression to an extent, although it has different effects on the proliferation of HCC cells, at the various concentrations of this agent in vitro. Such effects of tamoxifen on TGF-beta1 expression may inhibit the growth and progression of HCCs over-expressing TGF-beta1 in vivo.