HBx regulates transcription factor PAX8 stabilization to promote the progression of hepatocellular carcinoma

Ubiquitin: A double-edged sword in hepatitis B virus-induced hepatocellular carcinoma

Hepatitis B virus is one of the leading causes behind the neoplastic transformation of liver tissue and associated mortality. Despite the availability of many therapies and vaccines, the pathogenic landscape of the virus remains elusive; urging the development of novel strategies based on the fundamental infectious and transformative modalities of the virus-host interactome. Ubiquitination is a widely observed post-translational modification of several proteins, which either regulates the proteins' turnover or impacts their functionalities. In recent years, ample amount of literature has accumulated regarding the ubiquitination dynamics of the HBV proteins as well as the host proteins during HBV infection and carcinogenesis; with direct and detailed characterization of the involvement of HBV in these processes. Interestingly, while many of these ubiquitination events restrict HBV life cycle and carcinogenesis, several others promote the emergence of hepatocarcinoma by putting the virus in an advantageous position. This review sums up the snowballing literature on ubiquitination-mediated regulation of the host-HBV crosstalk, with special emphasis on its influence on the establishment and progression of hepatocellular carcinoma on a molecular level. With the advent of cutting-edge ubiquitination-targeted therapeutic approaches, the findings emanating from this review may potentiate the identification of novel anti-HBV targets for the formulation of novel anticancer strategies to control the HBV-induced hepato-carcinogenic process on a global scale.

Transcription factor E4F1 as a regulator of cell life and disease progression

E4F transcription factor 1 (E4F1), a member of the GLI-Kruppel family of zinc finger proteins, is now widely recognized as a transcription factor. It plays a critical role in regulating various cell processes, including cell growth, proliferation, differentiation, apoptosis and necrosis, DNA damage response, and cell metabolism. These processes involve intricate molecular regulatory networks, making E4F1 an important mediator in cell biology. Moreover, E4F1 has also been implicated in the pathogenesis of a range of human diseases. In this review, we provide an overview of the major advances in E4F1 research, from its first report to the present, including studies on its protein domains, molecular mechanisms of transcriptional regulation and biological functions, and implications for human diseases. We also address unresolved questions and potential research directions in this field. This review provides insights into the essential roles of E4F1 in human health and disease and may pave the way for facilitating E4F1 from basic research to clinical applications.

HBx promotes hepatocellular carcinoma progression by repressing the transcription level of miR-187-5p

HBV-associated hepatitis B virus x protein (HBx) plays multiple roles in the development of hepatocellular carcinoma. In our prior study, we discovered that miR-187-5p expression was inhibited by HBx. To investigate the underlying molecular mechanism of HBx-mediated miR-187-5p downregulation in hepatocellular carcinoma cells, effects of HBx and miR-187-5p on hepatoma carcinoma cell were observed, as well as their interactions. Through in vitro and in vivo experiments, we demonstrated that overexpression of miR-187-5p inhibited proliferation, migration, and invasion. Simultaneously, we observed a dysregulation in the expression of miR-187-5p in liver cancer cell lines, which may be attributed to transcriptional inhibition through the E2F1/FoxP3 axis. Additionally, we noted that HBx protein is capable of enhancing the expression of E2F1, a transcription factor that promotes the expression of FoxP3. In conclusion, our results suggest that the inhibitory effect of HBx on miR-187-5p is mediated through the E2F1/FoxP3 axis. As shown in this work, HBx promotes hepatoma carcinoma cell proliferation, migration, and invasion through the E2F1/FoxP3/miR-187 axis. It provides a theoretical basis for finding therapeutic targets that will help clinic treatment for HCC.

Advances in experimental animal models of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor with insidious early symptoms, easy metastasis, postoperative recurrence, poor drug efficacy, and a high drug resistance rate when surgery is missed, leading to a low 5-year survival rate. Research on the pathogenesis and drugs is particularly important for clinical treatment. Animal models are crucial for basic research, which is conducive to studying pathogenesis and drug screening more conveniently and effectively. An appropriate animal model can better reflect disease occurrence and development, and the process of anti-tumor immune response in the human body. This review summarizes the classification, characteristics, and advances in experimental animal models of HCC to provide a reference for researchers on model selection.

Integrated analysis of intratumoral biomarker and tumor-associated macrophage to improve the prognosis prediction in cancer patients

BACKGROUND

The lack of effective and accurate predictive indicators remains a major bottleneck for the improvement of the prognosis of patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Hepatitis B virus X (HBx) has been widely suggested as a critical pathogenic protein for HBV-driven liver carcinogenesis, while tumor-associated macrophage (TAM) infiltration is also closely related to the tumorigenesis and progression of HCC. However, few studies have determined whether combining HBx expression with TAM populations could increase the accuracy of prognostic prediction for HBV-related HCC.

METHODS

The study cohort enrolling 251 patients with HBV-related HCC was randomly split into a training and a validation group (ratio 1:1). The expression levels of HBx and TAM marker CD68 in HCC samples were detected by immunohistochemistry. Kaplan-Meier curves, Cox regression and Harrell's concordance index (C-index) analysis were conducted to evaluate the prognostic significance of these indicators alone or in combination.

RESULTS

The expression level of HBx was strongly correlated with CD68⁺ TAM infiltration in HCC tissues. Elevated HBx or CD68 expression indicated poorer overall survival (OS) and progression-free survival (PFS) after hepatectomy, and both of them were independent risk factors for postoperative survival. Meanwhile, patients with both high HBx and CD68 levels had worst clinical outcomes. Moreover, integrating HBx and CD68 expression with clinical indicators (tumor size and micro-vascular invasion) showed the best prognostic potential with highest C-index value for survival predictivity, and this proposed model also performed better than several conventional classifications of HCC.

CONCLUSION

Combining the expression of intratumoral HBx, CD68⁺ TAM population and clinical variables could enable better prognostication for HBV-related HCC after hepatectomy, thus providing novel insights into developing more effective clinical prediction model based on both molecular phenotypes and tumor-immune microenvironment.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

Aerobic glycolysis enhances HBx-initiated hepatocellular carcinogenesis via NF-κBp65/HK2 signalling

BACKGROUND

Aerobic glycolysis has been recognized as one of the growth-promoting metabolic alterations of cancer cells. Emerging evidence indicates that nuclear factor κB (NF-κB) plays significant roles in metabolic adaptation in normal cells and cancer cells. However, whether and how NF-κB regulates metabolic reprogramming in hepatocellular carcinoma (HCC), specifically hepatitis B virus X protein (HBx)-initiated HCC, has not been determined.

METHODS

A dataset of the HCC cohort from the TCGA database was used to analyse the expression of NF-κB family members. Expression of NF-κBp65 and phosphorylation of NF-κBp65 (p-p65) were detected in liver tissues from HBV-related HCC patients and normal controls. A newly established HBx^+/+/NF-κBp65^f/f and HBx^+/+/NF-κBp65^Δhepa spontaneous HCC mouse model was used to investigate the effects of NF-κBp65 on HBx-initiated hepatocarcinogenesis. Whether and how NF-κBp65 is involved in aerobic glycolysis induced by HBx in hepatocellular carcinogenesis were analysed in vitro and in vivo.

RESULTS

NF-κBp65 was upregulated in HBV-related HCC, and HBx induced NF-κBp65 upregulation and phosphorylation in vivo and in vitro. Hepatocyte-specific NF-κBp65 deficiency remarkably decreased HBx-initiated spontaneous HCC incidence in HBx-TG mice. Mechanistically, HBx induced aerobic glycolysis by activating NF-κBp65/hexokinase 2 (HK2) signalling in spontaneous hepatocarcinogenesis, and overproduced lactate significantly promoted HCC cell pernicious proliferation via the PI3K (phosphatidylinositide 3-kinase)/Akt pathway in hepatocarcinogenesis.

CONCLUSION

The data elucidate that NF-κBp65 plays a pivotal role in HBx-initiated spontaneous HCC, which depends on hyperactive NF-κBp65/HK2-mediated aerobic glycolysis to activate PI3K/Akt signalling. Thus, phosphorylation of NF-κBp65 will be a potential therapeutic target for HBV-related HCC.

HBV X Protein Induces Degradation of UBXN7, a Novel Negative Regulator of NF-κB Signaling, to Promote HBV Replication

Chronic hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma. However, the function and mechanism of the effect of HBV on host protein ubiquitination remain largely unknown. We aimed at characterizing whether and how HBV promotes self-replication by affecting host protein ubiquitination. In this study, we identified UBXN7, a novel inhibitor for nuclear factor kappa B (NF-κB) signaling, was degraded via interaction with HBV X protein (HBx) to activate NF-κB signaling and autophagy, thereby affecting HBV replication. The expression of UBXN7 was analyzed by Western blot and quantitative reverse transcription polymerase chain reaction in HBV-transfected hepatoma cells and HBV-infected primary human hepatocytes (PHHs). The effects of UBXN7 on HBV replication were analyzed by using in vitro and in vivo assays, including stable isotope labeling by amino acids in cell culture (SILAC) analysis. Changes in HBV replication and the associated molecular mechanisms were analyzed in hepatoma cell lines. SILAC analyses showed that the ubiquitination of UBXN7 was significantly increased in HepG2.2.15 cells compared with control cells. After HBV infection, HBx protein interacted with UBXN7 to promote K48-linked ubiquitination of UBXN7 at K99, leading to UBXN7 degradation. On the other hand, UBXN7 interacted with the ULK domain of IκB kinase β through its ubiquitin-associating domain to facilitate its degradation. This in turn reduced NF-κB signaling, leading to reduced autophagy and consequently decreased HBV replication.

VCP interaction with HMGB1 promotes hepatocellular carcinoma progression by activating the PI3K/AKT/mTOR pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common pathological type of liver cancer. Valosin-containing protein (VCP) is a member of the AAA-ATPase family associated with multiple molecular functions and involved in tumor metastasis and prognosis. However, the role of VCP in HCC progression is still unclear.

METHODS

We examined the expression of VCP in HCC using the RNA sequencing and microarray data from public databases and measured it in clinical samples and cell lines by western blot, and immunohistochemistry (IHC). We also evaluated the correlation between VCP and clinical features. The VCP-interacting proteins were identified by co-immunoprecipitation combined with mass spectrometry (CoIP/MS). The underlying molecular mechanisms were investigated using in vitro and in vivo models of HCC.

RESULTS

We found that VCP expression is significantly increased in tumor tissues and is associated with advanced TNM stages and poorer prognosis in HCC patients. In vitro analyses revealed that VCP overexpression promoted HCC cell proliferation, migration, and invasion via PI3K/AKT/mTOR pathway activation. Conversely, VCP knockdown resulted in the reverse phenotypes. In vivo studies indicated that up-regulated VCP expression accelerated tumor growth in a subcutaneous HCC model. The D1 domain of VCP and A box of HMGB1 were identified as the critical regions for their interaction, and D1 area was required for the tumor-promoting effects induced by VCP expression. VCP enhanced the protein stability of HMGB1 by decreasing its degradation via ubiquitin-proteasome process. Inhibition of HMGB1 markedly attenuated VCP-mediated HCC progression and downstream activation of PI3K/AKT/mTOR signals.

CONCLUSION

Collectively, these findings demonstrate that VCP is a potential prognostic biomarker in HCC and exhibits oncogenic roles via PI3K/AKT/mTOR pathway activation. HMGB1 played an essential role in VCP-mediated HCC progression, indicating that VCP and HMGB1 are potential therapeutic targets in human HCC.

Transcriptional regulators of human oncoviruses: structural and functional implications for anticancer therapy

Transcription is often the first biosynthetic event of viral infection. Viruses produce preferentially viral transcriptional regulators (vTRs) essential for expressing viral genes and regulating essential host cell proteins to enable viral genome replication. As vTRs are unique viral proteins that promote the transcription of viral nucleic acid, vTRs interact with host proteins to suppress detection and immune reactions to viral infection. Thus, vTRs are promising therapeutic targets that are sequentially and structurally distinct from host cell proteins. Here, we review vTRs of three human oncoviruses: HBx of hepatitis B virus, HBZ of human T-lymphotropic virus type 1, and Rta of Epstein-Barr virus. We present three cunningly exciting and dangerous transcription strategies that make viral infections so efficient. We use available structural and functional knowledge to critically examine the potential of vTRs as new antiviral-anticancer therapy targets. For each oncovirus, we describe (i) the strategy of viral genome transcription; (ii) vTRs' structure and binding partners essential for transcription regulation; and (iii) advantages and challenges of vTR targeting in antiviral therapies. We discuss the implications of vTR regulation for oncogenesis and perspectives on developing novel antiviral and anticancer strategies.

The Functions of Hepatitis B Virus Encoding Proteins: Viral Persistence and Liver Pathogenesis

About 250 million people worldwide are chronically infected with Hepatitis B virus (HBV), contributing to a large burden on public health. Despite the existence of vaccines and antiviral drugs to prevent infection and suppress viral replication respectively, chronic hepatitis B (CHB) cure remains a remote treatment goal. The viral persistence caused by HBV is account for the chronic infection which increases the risk for developing liver cirrhosis and hepatocellular carcinoma (HCC). HBV virion utilizes various strategies to escape surveillance of host immune system therefore enhancing its replication, while the precise mechanisms involved remain elusive. Accumulating evidence suggests that the proteins encoded by HBV (hepatitis B surface antigen, hepatitis B core antigen, hepatitis B envelope antigen, HBx and polymerase) play an important role in viral persistence and liver pathogenesis. This review summarizes the major findings in functions of HBV encoding proteins, illustrating how these proteins affect hepatocytes and the immune system, which may open new venues for CHB therapies.

Autophagy induction regulates aquaporin 3-mediated skin fibroblasts aging

BACKGROUND

Long- and short-term ultraviolet (UV) exposure have distinct biological effects on human fibroblasts.

OBJECTIVES

This study aimed to elucidate the underlying mechanisms of the biological effects of UV exposure on human skin fibroblasts.

METHOD

We subjected human skin fibroblast cells with or without AQP3, DEDD, or Beclin1 manipulation to UVA treatment and evaluated autophagy and senescence/aging in them.

RESULTS

Short-term UVA irradiation induced autophagy and upregulated AQP3 but not senescence, whereas long-term UVA irradiation inhibited autophagy, AQP3, and senescence/aging in vitro and in vivo. Silencing AQP3 abolished short-term UVA irradiation-induced autophagy and led to cellular senescence, whereas AQP3 overexpression partially rescued the senescence and autophagy inhibition induced by long-term UVA exposure in vitro. Mechanistically, the transcription factor JUN was found to bind to the AQP3 promoter to activate its transcription following short-term UVA exposure. Subsequently, AQP3 interacted with DEDD to induce its ubiquitination-mediated degradation and promote autophagy, and bound to Beclin1 to directly activate autophagy. Finally, autophagy induced by AQP3 overexpression robustly prevented UVA-induced senescence/aging in vitro and in vivo.

CONCLUSIONS

Thus, our study indicates that AQP3 controls skin fibroblasts photoaging by regulating autophagy and represents a potential target for future interventions against skin aging.

HBx induces hepatocellular carcinogenesis through ARRB1-mediated autophagy to drive the G1/S cycle

The hepatitis B virus X protein (HBx) is involved in the process of hepatocellular carcinoma via the activation of various oncogenes. Our previous study indicated that ARBB1 (arrestin beta 1) promotes hepatocellular carcinogenesis (HCC). However, the role of ARRB1 in HBx-related HCC remains unclear. Herein, we identified that ARRB1 was upregulated by HBx in vivo and in vitro. Arrb1 deficiency suppressed HBx-induced hepatocellular carcinogenesis in several mouse models. Furthermore, knockdown of ARRB1 blocked HBx-induced macroautophagic/autophagic flux and disrupted the formation of autophagosomes. ARRB1 interacted with HBx, and the autophagic core protein MAP1LC3/LC3, a scaffolding protein, was essential for complete autophagy. Inhibition of autophagy by 3-methyladenine or interference of ATG5 or ATG7 attenuated HBx-induced cell cycle acceleration and the subsequent proliferative response via the induction of G₁/S arrest. The absence of autophagy abolished the phosphorylation of CDK2 and the activity of the CDK2-CCNE1 complex. Our results demonstrate that ARRB1 plays a critical role in HBV-related HCC via modulating autophagy and the CDKN1B-CDK2-CCNE1-E2F1 axis and indicate that ARRB1 may be a potential therapeutic target for HCC.

HBx promotes hepatocarcinogenesis by enhancing phosphorylation and blocking ubiquitinylation of UHRF2

BACKGROUND AND AIMS

The major cause of Hepatocellular carcinoma (HCC) is acute or chronic infection caused by hepatotropic viruses and HBV infection is the main cause. UHRF2, a ubiquitin-protein ligase E3, is associated with cancer development. This study aimed to investigate the connection and mechanism between UHRF2 and HBV-associated HCC.

METHODS

The expression of UHRF2 in human HBV-positive HCC tissues and paracancerous tissues was detected by western blot and tissue microarray. The effects of UHRF2 on invasion, migration and proliferation were detected in HBV-positive hepatoma cell lines. Furthermore, western blot, immunofluorescence, Co-immunoprecipitation and ubiquitination assays were used to explore the relationship and mechanism between UHRF2 and HBV-associated HCC.

RESULTS

HBV-positive HCC tissues had higher UHRF2 expression levels than adjacent non-tumor tissues. The HBV-positive HCC patients with a low UHRF2 level in cancer tissues had longer overall and recurrence-free survival compared with those with a high UHRF2 level. UHRF2 induced invasion, migration and proliferation in human HBV-positive HCC cell lines HepG2.2.15 and Hep AD38(-). HBx, an encoding protein of HBV, maintained the stability of UHRF2 by blocking the ubiquitination of UHRF2. HBx up-regulated CDK2 expression through ETS1. UHRF2 bound to CDK2 directly and enhanced UHRF2 phosphorylation at serine 643.

CONCLUSIONS

These results suggest that HBx-ETS1-CDK2-UHRF2 pathway plays an important role in the pathogenesis of HBV-associated HCC and represents new therapeutic targets for human HCC.

CLINICAL TRIALS REGISTRATION

ChiCTR2000041416.

Crosstalk between lncRNA DANCR and miR-125b-5p in HCC cell progression

Objective:

To investigate the mechanism of long noncoding RNA (lncRNA) DANCR on the progression of hepatocellular carcinoma (HCC) cells.

Methods:

The expression levels of DANCR and miR-125b-5p were measured in normal hepatocytes (LO2) and HCC cell lines by quantitative reverse transcription polymerase chain reaction. HepG2 and Huh-7 cells were transfected with sh-DANCR, the negative control (sh-NC), miR-125b-5p mimic, or mimic NC or cotransfected with sh-DANCR and miR-125b-5p inhibitor. HCC cell proliferation was assessed through CCK8 and plate colony formation assay. Western blot quantified the expression levels of Bcl-2, Bax, caspase-3, and cleaved-caspase-3. Apoptotic rate was detected as well as migratory and invasive capacities. The implication of the MAPK signal pathway was assessed by detecting the expression levels of p38, ERK1/2, JNK, p-p38, p-ERK1/2, and p-JNK. Interactions between DANCR and miR-125b-5p were detected by dual luciferase reporter assay.

Results:

In HCC cells, DANCR was highly expressed and miR-125b-5p was decreased. sh-DANCR or miR-125b-5p mimic stimulation reduced HepG2 or Huh-7 cell progression while promoted cell apoptosis evidenced by increased apoptotic rate, elevated levels of Bax and cleaved-caspase-3, and decreased Bcl-2. Moreover, the migration rate and invasiveness of HCC cells were also inhibited by sh-DANCR and miR-125b-5p mimic. Levels of p-p38/p38, p-ERK1/2/ERK1/2, and p-JNK/JNK were suppressed by sh-DANCR and miR-125b-5p mimic. LncRNA DANCR negatively targeted and directly bound to miR-125b-5p. Knockdown of miR-125b-5p could reverse the inhibitory effects of sh-DANCR on HCC cells.

Conclusion:

In HCC cells, lncRNA DANCR sponges miR-125b-5p and activates MAPK pathway, thus facilitating HCC cell progression.

Secreted TRAIL gene-modified adipose-derived stem cells exhibited potent tumor-suppressive effect in hepatocellular carcinoma cells

Objective

Considering the potential of adipose‐derived stem cells (ADSCs) migrating towards cancer cells, this study was performed to explore the function of tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) modified ADSCs on the development and progression of hepatocellular carcinoma (HCC).

Methods

ADSCs were extracted from human adipose tissues and identified through immunofluorescence and flow cytometry. Oil red staining and alizarin red staining were performed to clarify the differentiation potential of ADSCs. AAV‐CMV‐sTRAIL was transfected into ADSCs before Western blot and Transwell measurements. sTRAIL‐ADSCs were cocultured with HCC cells to explore its effect on the proliferation and apoptosis of HCC cells. The possible effect of sTRAIL‐ADSCs or ADSCs on tumor growth and metastasis was determined in vivo using xenograft nude mouse models.

Results

ADSCs were successfully extracted from adipose tissues, which were confirmed by cell morphology and positive expressions of CD44 and CD105. ADSCs were found with differentiation potential. After transfection, TRAIL was stably expressed in sTRAIL‐ADSCs. Both ADSCs and sTRAIL‐ADSCs can migrate towards HCC cells. In addition, sTRAIL‐ADSCs can promote the cell apoptosis and inhibit cell proliferation in vitro, on parallel it can also suppress epithelial‐mesenchymal transition, tumor growth, and metastasis in vivo.

Conclusion

TRAIL modified ADSCs can migrate towards HCC cells to inhibit tumor growth and the metastasis of implanted HCC tumors, which hints TRAIL modified ADSCs may be a new therapeutic approach for HCC treatment.

MACC1-AS1 promotes hepatocellular carcinoma cell invasion and proliferation by regulating PAX8

Long noncoding RNAs play vital roles in several biological processes, including cell growth and embryonic development. We showed that MACC1-AS1 was overexpressed in hepatocellular carcinoma (HCC) cells and tissues. The MACC1-AS1 expression level was dramatically upregulated in HCC samples compared to adjacent normal samples, and 77.5% (31 of 40) of HCC samples showed overexpression of MACC1-AS1. Ectopic MACC1-AS1 expression enhanced cell proliferation and cyclin D1 expression in both SMMC7721 and MHCC-97H cells. Ectopic expression of MACC1-AS1 promoted vimentin, N-cadherin and snail expression and decreased E-cadherin expression in both SMMC7721 and MHCC-97H cells. MACC1-AS1 overexpression also induced cell invasion in the same two cell lines. Furthermore, MACC1-AS1 overexpression enhanced PAX8 expression in HCC cells. The PAX8 level was dramatically increased in HCC samples compared to adjacent normal samples, and 75% (30 of 40) of HCC samples showed overexpression of PAX8. PAX8 expression was positively correlated with MACC1-AS1 expression in HCC samples. MACC1-AS1 overexpression promoted HCC cell proliferation, EMT and invasion through regulating PAX8. These results suggest that MACC1-AS1 acts as an oncogene in the development of HCC.