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PDF - 50KB, Supplementary Table S1: Primers for RT-PCR, and Supplementary Table S2: Antibody list

PDF - 2058 KB, Knockdown of ASLby shRNA inhibited cell migration in ML-1 cells

PDF - 1437 KB, Knockdown of ASL by shAsl111 inhibits cell growth in vitro

Arginine biosynthesis and nitric oxide (NO) production are important for cancer homeostasis. Degradation of arginine may be used to inhibit liver tumors with low argininosuccinate synthetase (ASS) expression. In this report, we investigated an alternative therapeutic approach by targeting argininosuccinate lyase (ASL). ASL is transcriptionally induced by endoplasmic reticulum stress and is overexpressed in some human liver tumors. Knockdown of ASL expression by short hairpin RNA (shRNA) in three liver cancer cell lines, ML-1, HuH-7, and HepG2, decreased colony formation in vitro and tumor growth in vivo. Furthermore, lentiviral infection of ASL shRNA inhibited tumor growth in a therapeutic animal tumor model. Analysis of ASL shRNA on the cell-cycle progression revealed a G2–M delay. Among cell-cycle regulatory molecules, cyclin A2 expression was reduced. Reintroduction of exogenous cyclin A2 restored the cell growth in ASL-knockdown cells. Autophagy was observed in the cells treated with ASL shRNA, as shown by an increase in LC3-II levels and autophagosome formation. The total cellular arginine level was not altered significantly. Inhibition of autophagy further attenuated cell growth, suggesting that autophagy induced by ASL shRNA plays a feedback prosurvival function. Knockdown of ASL reduced NO content, and addition of NO donor partially recovered the growth inhibition by ASL shRNA. In summary, downregulation of ASL attenuated tumor growth and the inhibition was mainly mediated by a decrease of cyclin A2 and NO. Mol Cancer Ther; 12(11); 2505–16. ©2013 AACR.

PDF - 2780 KB, ASL promoter activity induced by ER stress

PDF - 3467 KB, ASL and GRP78 expression in liver cancer tissue

Overexpression of the serine/threonine kinase GLK/MAP4K3 in human lung cancer is associated with poor prognosis and recurrence, however, the role of GLK in cancer recurrence remains unclear. Here, we report that transgenic GLK promotes tumor metastasis and cell migration through the scaffold protein IQ motif–containing GTPase-activating protein 1(IQGAP1). GLK transgenic mice displayed enhanced distant metastasis. IQGAP1 was identified as a GLK-interacting protein; two proline-rich regions of GLK and the WW domain of IQGAP1 mediated this interaction. GLK and IQGAP1 colocalized at the leading edge including filopodia and lamellipodia of migrating cells. GLK directly phosphorylated IQGAP1 at Ser-480 enhancing Cdc42 activation and subsequent cell migration. GLK-induced cell migration and lung cancer metastasis were abolished by IQGAP1 depletion. Consistently, human NSCLC patient tissues displayed increased phospho-IQGAP1, which correlated with poor survival. Collectively, GLK promotes lung cancer metastasis by binding to, phosphorylating, and activating IQGAP1.Significance:These findings show the critical role of the GLK–IQGAP cascade in cell migration and tumor metastasis, suggesting it as a potential biomarker and therapeutic target for lung cancer recurrence.

Cell tracking in time-lapse microscopy images of primary lung epithelial cells from wild-type (WT), GLK-deficient (KO), and GLK transgenic (Polâ…¡-GLK)) mice. The tracked path of the mGFP-positive cell is shown as the line.

Supplementary Methods, Figures, and Movies - Supplementary File accompanying the manuscript provides additional details regarding the methods of immunoblotting, cell migration and proliferation assays, time-lapse live cell imaging, FRET, and in vitro kinase assays. Additionally, we also provide IHC data of mouse tissues (Fig. S1), cell migration assays using primary lung cells or lung cancer cell lines (Fig. S2-S6), PLA data (Fig. S7), as well as five N-SIM movies (Movies S1-S5).

Video.avi GLK co-localizes with IQGAP1 at filopodia and lamellipodia of a cell (Cell #3).

Cell tracking in time-lapse microscopy images from of lung epithelial cells from littermate wild-type (WT), GLK transgenic (Polâ…¡-GLK), GLK transgenic/IQGAP1-heterozygous (Polâ…¡-GLK;IQGAP1+/- ), and GLK transgenic/IQGAP1 knockout (Polâ…¡-GLK;IQGAP1-/- ) mice. The tracked path of the migration cell is shown as the line.

Video4.avi GLK co-localizes with IQGAP1 at the leading edge of a migrating cell (Cell #4)

Video 5.avi GLK co-localizes with IQGAP1 at the leading edge of a migrating cell (Cell #5).

Purpose Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC), a leading cause of cancer-related death worldwide. The HCC patients who harbor HBV pre-S2 mutant, an oncoprotein that plays key roles in HCC development, have been closely associated with a worse prognosis after curative surgical resection, suggesting an urgent need for alternative therapeutic options to improve their survival. In this study, we aimed to evaluate the expression profiles of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1), two of the most well-studied immune checkpoint molecules that promote tumor immune evasion, in tumor of the pre-S2 mutant-positive/high HCC patients. Methods We classified 40 HBV-related HCC patients into the pre-S2-positive/high and -negative/low groups by a next-generation sequencing-based approach. The fluorescent immunohistochemistry staining was performed to detect the expression of PD-1 and PD-L1 in HCC tissues of patients. Results We showed that patients with either deletion spanning pre-S2 gene segment or high percentage of pre-S2 plus pre-S1+pre-S2 deletion (the pre-S2 mutant-positive/high group) exhibited a significantly higher density of PD-L1-positive cells in HCC tissues than those without. Moreover, the percentage of pre-S2 plus pre-S1+pre-S2 deletion displayed a high positive correlation with the density of PD-L1-positive cells in HCC tissues. Conclusion The increased expression of PD-L1 in tumor tissues of the pre-S2 mutant-positive HCC patients suggest that pre-S2 mutant may play a potential role in dysregulation of tumor immune microenvironment in the progression of HBV-related HCC, implicating for the development of future therapeutic strategies.

Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer. Although many surgical and nonsurgical therapeutic options have been established for treating HCC, the overall prognosis for HCC patients receiving different treatment modalities remains inadequate, which causes HCC to remain among the most life-threatening human cancers worldwide. Therefore, it is vitally important and urgently needed to develop valuable and independent prognostic biomarkers for the early prediction of poor prognosis in HCC patients, allowing more time for more timely and appropriate treatment to improve the survival of patients. As the most abundant protein in plasma, human serum albumin (ALB) is predominantly expressed by the liver and exhibits a wide variety of essential biological functions. It has been well recognized that serum ALB level is a significant independent biomarker for a broad spectrum of human diseases including cancer. Moreover, ALB has been commonly used as a potent biomaterial and therapeutic agent in clinical settings for the treatment of various human diseases. This review provides a comprehensive summary of the evidence from the up-to-date published literature to underscore the prognostic significance of serum ALB level and various ALB-based mono- and combination biomarkers in the prediction of the prognosis of HCC patients after treatment with different surgical, locoregional, and systemic therapies.

Hepatocellular carcinoma (HCC) is among the most common and lethal human cancers worldwide. Despite remarkable advances in treatment, high mortality in HCC patients remains a big challenge. To develop novel therapeutic strategies for HCC is thus urgently needed to improve patient survival. Dendritic cells (DC)-based vaccines can induce tumor-specific immunity and have emerged as a promising approach for treating HCC patients; however, its effectiveness needs to be improved. Recently, blockade of programmed death ligand 1 (PD-L1) immune checkpoint pathway has been shown to enhance anti-tumor immune responses and exhibited great potential in HCC therapy.In this study, we generated DC vaccine by pulsing the C57BL/6J mouse bone marrow-derived DC with mouse hepatoma Hep-55.1C cell lysate. We developed a therapeutic strategy combining DC vaccine and PD-L1 inhibitor for HCC and evaluated its efficacy in an orthotopic HCC mouse model in which Hep-55.1C cells were directly injected into left liver lobe of C57BL/6J mouse.Compared with a control group of mice, groups of mice treated with DC vaccine or PD-L1 inhibitor had significantly improved overall survival, reduced tumor volume, and increased tumor cell apoptosis. Remarkably, combination treatment with DC vaccine and PD-L1 inhibitor led to considerably longer overall survival, smaller tumor volume, and higher tumor cell apoptosis of mice than either treatment alone in a dose-dependent manner through inducing a stronger anti-tumor cytotoxic T cell response.Our data suggested that combination therapy with DC vaccine and PD-L1 inhibitor might have great promise as a novel treatment strategy for HCC.

In addition to the fundamental role of insulin-like growth factor (IGF)/IGF-1 receptor (IGF-1R) signaling dysregulation in cancer initiation and proliferation, the IGF/IGF-1R signaling also plays an important role in the maintenance of stem cell characteristics and enhancement of stem cell-based therapeutic efficacy. This review focused on the role of IGF/IGF-1R signaling in preclinical IGF-targeted therapies, including IGF-1R monoclonal antibodies, IGF-1R tyrosine kinase inhibitors, and neutralizing antibodies of IGFs in multiple tumors and endocrine disorders. On the other hand, the function of IGF/IGF-1R signaling in stem cell self-renewal, pluripotency and therapeutic efficacy in regenerative medicine was outlined. Finally, the review summarized ongoing studies on IGF/IGF-1R signaling blockade in multiple cancers and highlighted the IGF-1R signaling modifications in stem cells as a potential strategy to improve stem cell-based therapeutics in regenerative medicine.

Hepatocellular carcinoma (HCC) is, globally, one of the most prevalent and deadly human cancers, despite curative surgical resection, its high recurrence rate after surgery remains a large threat, resulting in poor patient survival. The hepatitis B virus (HBV) pre-S2 mutant that harbors deletions spanning the pre-S2 gene segment has emerged as an important oncoprotein for HCC development and a valuable prognostic biomarker for HCC recurrence, however, its relationship with clinicopathological factors is largely unexplored. In this study, the correlation of the deletion spanning the pre-S2 gene segment with clinicopathological factors and the association of such correlation with HCC recurrence after curative surgical resection were examined in HBV-related HCC patients. Inverse correlation between serum albumin level and the deletion spanning the pre-S2 gene segment was identified. HCC patients with the presence of the deletion spanning the pre-S2 gene segment and a low serum albumin level were associated with higher HCC recurrence than patients with either factor alone or neither factor were. Moreover, a combination of the serum albumin level and the deletion spanning the pre-S2 gene segment exhibited better performance than that of either factor alone in predicting HCC recurrence. Collectively, this study shows an association of low serum albumin level with pre-S2 mutant-positive HCC patients, and validates the prognostic value of this association in identifying patients with higher HCC recurrence after curative surgical resection.

Hepatocellular carcinoma (HCC) is one of the most frequent and fatal human cancers worldwide and its development and prognosis are intimately associated with chronic infection with hepatitis B virus (HBV). The identification of genetic mutations and molecular mechanisms that mediate HBV-induced tumorigenesis therefore holds promise for the development of potential biomarkers and targets for HCC prevention and therapy. The presence of HBV pre-S gene deletions in the blood and the expression of pre-S deleted proteins in the liver tissues of patients with chronic hepatitis B and HBV-related HCC have emerged as valuable biomarkers for higher incidence rates of HCC development and a higher risk of HCC recurrence after curative surgical resection, respectively. Moreover, pre-S deleted proteins are regarded as important oncoproteins that activate multiple signaling pathways to induce DNA damage and promote growth and proliferation in hepatocytes, leading to HCC development. The signaling molecules dysregulated by pre-S deleted proteins have also been validated as potential targets for the prevention of HCC development. In this review, we summarize the clinical and molecular implications of HBV pre-S gene deletions and pre-S deleted proteins in HCC development and recurrence and highlight their potential applications in HCC prevention and therapy.

Although many surgical and nonsurgical therapeutic options have been well-established, hepatocellular carcinoma (HCC) remains the third most common cause of cancer-related death worldwide. Therefore, the discovery of novel potential therapeutic strategies is still urgently required for improving survival and prognosis of HCC patients. As the most potent antigen-presenting cells in the human immune system, dendritic cells (DCs) play an important role in activating not only innate but also adaptive immune responses to specifically destroy tumor cells. As a result, DC-based vaccines, which are prepared by different tumor-antigen-pulsing strategies or maturation-stimulating reagents, either alone or in combination with various anticancer therapies and/or immune effector cells, have been developed as a promising personalized cancer immunotherapy. This review provides a comprehensive summary of the evidence from clinical trials evaluating the safety, feasibility, and efficacy of DC-based vaccines in treating HCC patients and highlights the data from recent preclinical studies regarding the development of promising strategies for optimizing the efficacy of DC-vaccine-based immunotherapy for HCC.

Background and aim Hepatocellular carcinoma (HCC) remains a serious cause of cancer-related deaths worldwide. Developing new therapeutic strategies is urgently needed to improve the outcomes of HCC patients. Dendritic cell (DC)-based vaccines and programmed death 1 (PD-1) immune checkpoint inhibitors have been regarded as potential immunotherapeutics for HCC. However, the therapeutic efficacy of combining these two treatments for HCC remains to be evaluated. Methods In this study, DCs were derived from mouse bone marrow and pulsed with mouse HCC cell lysates to generate a DC vaccine. A monoclonal antibody that blocks the interaction of mouse PD-1 with its ligands was used as a PD-1 inhibitor. An orthotopic HCC mouse model was established to assess the effect of a DC vaccine in combination with a PD-1 inhibitor on overall survival and tumor volume. Results Compared with the untreated control, single treatment with a DC vaccine or PD-1 inhibitor prolonged the overall survival and reduced the tumor volume of HCC mice. Further, compared with the single treatment with the DC vaccine or the PD-1 inhibitor, a combination treatment using both agents elicited a higher cytotoxicity of T cells against HCC cells and resulted in a better overall survival, smaller tumor volume, and greater tumor cell apoptosis in HCC mice. Conclusions Our results suggest that a combination treatment with DC vaccine and PD-1 inhibitor may be a promising therapeutic strategy for HCC.

Chronic hepatitis B virus (HBV) infection is a major risk factor for the development of hepatocellular carcinoma (HCC), the leading cause of cancer-related death worldwide. Despite progress in the prevention and therapy of HCC, high incidence and recurrence rates of HCC remain big threats, resulting in poor patient survival. Effective biomarkers and targets of HCC are therefore urgently needed for better management and to improve patient outcomes. Pre-S mutants have been well demonstrated as HBV oncoproteins that play important roles in HCC development through activation of multiple oncogenic signal pathways in hepatocytes, in vitro and in vivo. The presence of pre-S mutants in patients with chronic HBV infection and HBV-related HCC has been associated with a significantly higher risk of HCC development and recurrence after curative surgical resection, respectively. In this review, we summarize the roles of pre-S mutants as biomarkers for predicting HBV-related HCC development and recurrence, and highlight the pre-S mutants-activated oncogenic signal pathways as potential targets for preventing HBV-related HCC development.

Background: Hepatocellular carcinoma (HCC) is among the most common and lethal human cancers worldwide. Despite remarkable advances in treatment, high mortality in HCC patients remains a big challenge. To develop novel therapeutic strategies for HCC is thus urgently needed to improve patient survival. Dendritic cells (DC)-based vaccines can induce tumor-specific immunity and have emerged as a promising approach for treating HCC patients; however, its effectiveness needs to be improved. Recently, blockade of programmed death ligand 1 (PD-L1) immune checkpoint pathway has been shown to enhance anti-tumor immune responses and exhibited great potential in HCC therapy. Methods: In this study, we generated DC vaccine by pulsing the C57BL/6J mouse bone marrow-derived DC with mouse hepatoma Hep-55.1C cell lysate. We developed a therapeutic strategy combining DC vaccine and PD-L1 inhibitor for HCC and evaluated its efficacy in an orthotopic HCC mouse model in which Hep-55.1C cells were directly injected into left liver lobe of C57BL/6J mouse. Results: Compared with a control group of mice, groups of mice treated with DC vaccine or PD-L1 inhibitor had significantly improved overall survival, reduced tumor volume, and increased tumor cell apoptosis. Remarkably, combination treatment with DC vaccine and PD-L1 inhibitor led to considerably longer overall survival, smaller tumor volume, and higher tumor cell apoptosis of mice than either treatment alone in a dose-dependent manner through inducing a stronger anti-tumor cytotoxic T cell response. Conclusion: Our data suggested that combination therapy with DC vaccine and PD-L1 inhibitor might have great promise as a novel treatment strategy for HCC.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Despite curative surgical resection, high recurrence of HCC after surgery results in poor patient survival. To develop prognostic markers is therefore important for better prevention and therapy of recurrent HCC to improve patient outcomes. Deletion mutations over the pre-S1 and pre-S2 gene segments of hepatitis B virus (HBV) have been closely associated with recurrence of HCC after curative surgical resection. In this study, we applied a next-generation sequencing-based approach to further evaluate the association of pre-S deletion regions with HCC recurrence. We demonstrated that the pre-S2 deletion (nucleotide 1 to 54) was the most predominant deletion regions of pre-S gene in plasma of HBV-related HCC patients. Moreover, patients with the pre-S2 deletion (nucleotide 1 to 54) exhibited a significantly higher risk of HCC recurrence after curative surgical resection than those without. The pre-S2 deletion (nucleotide 1 to 54) in plasma represented a prognostic factor that independently predicted HCC recurrence with greater performance than other clinicopathological and viral factors. Our data suggest that detection of the pre-S2 deletion (nucleotide 1 to 54) in plasma may be a promising noninvasive strategy for identifying patients at high risk for HCC recurrence after curative surgical resection.

Supplemental material, Supplementary_figure_legends_(1) for Combination therapy with dendritic cell vaccine and programmed death ligand 1 immune checkpoint inhibitor for hepatocellular carcinoma in an orthotopic mouse model by Chiao-Fang Teng, Ting Wang, Tzu-Hua Wu, Jia-Hui Lin, Fu-Ying Shih, Woei-Cherng Shyu and Long-Bin Jeng in Therapeutic Advances in Medical Oncology

Overexpression of the serine/threonine kinase GLK/MAP4K3 in human lung cancer is associated with poor prognosis and recurrence, however, the role of GLK in cancer recurrence remains unclear. Here, we report that transgenic GLK promotes tumor metastasis and cell migration through the scaffold protein IQ motif–containing GTPase-activating protein 1(IQGAP1). GLK transgenic mice displayed enhanced distant metastasis. IQGAP1 was identified as a GLK-interacting protein; two proline-rich regions of GLK and the WW domain of IQGAP1 mediated this interaction. GLK and IQGAP1 colocalized at the leading edge including filopodia and lamellipodia of migrating cells. GLK directly phosphorylated IQGAP1 at Ser-480 enhancing Cdc42 activation and subsequent cell migration. GLK-induced cell migration and lung cancer metastasis were abolished by IQGAP1 depletion. Consistently, human NSCLC patient tissues displayed increased phospho-IQGAP1, which correlated with poor survival. Collectively, GLK promotes lung cancer metastasis by binding to, phosphorylating, and activating IQGAP1. Significance: These findings show the critical role of the GLK–IQGAP cascade in cell migration and tumor metastasis, suggesting it as a potential biomarker and therapeutic target for lung cancer recurrence.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Early diagnosis and treatment of HCC remain a key goal for improving patient survival. Chronic hepatitis B virus (HBV) infection is a major risk factor for HCC development. Pre-S mutants harboring deletions in HBV large surface antigen have been well demonstrated as HBV oncoproteins that dysregulate multiple signaling pathways in hepatocytes, leading to HCC formation. The presence of pre-S mutants in plasma represents important predictive and prognostic markers for HCC in patients with chronic HBV infection. However, the method to detect pre-S mutants remains to be optimized. In this study, we developed a platform, based on the next-generation sequencing (NGS) technology, for detection of pre-S mutants in plasma of HBV-related HCC patients. Compared to the current TA cloning-based analysis, the NGS-based analysis could detect pre-S deletion quantitatively, and the detection rate was significantly more sensitive in 49 plasma analyzed (McNemar’s paired proportion test, P value

Evidence has emerged that stem cells represent a promising therapeutic tool for tissue engineering and regenerative medicine. Thus, identifying functional markers for selecting stem cells capable of superior self-renewal and pluripotency (or multipotency) and maintaining stem cell identity under appropriate culture conditions are critical for guiding the use of stem cells toward clinical applications. Many investigations have implicated the insulin-like growth factor 1 receptor (IGF1R) signaling in maintenance of stem cell characteristics and enhancement of stem cell therapy efficacy. IGF1R-expressing stem cells display robust pluripotent or multipotent properties. In this review, we summarize the essential roles of IGF1R signaling in self-renewal, pluripotency (or multipotency), and therapeutic efficacy of stem cells, including human embryonic stem cells, neural stem cells, cardiac stem cells, bone marrow mesenchymal stem cells, placental mesenchymal stem cells, and dental pulp mesenchymal stem cells. Modifying IGF1R signaling may thus provide potential strategies for maintaining stem cell properties and improving stem-cell-based therapeutic applications.

Metabolic syndrome has closely linked to the development of human hepatocellular carcinoma (HCC). By using the hepatitis B virus (HBV) X (HBx) transgenic mouse model, we studied the dynamic evolution of serum and liver profiles of lipids and global cDNA expression at different stages of HBx tumorigenesis. We observed that the lipid (triglycerides, cholesterol, and fatty acids) profiles revealed a biphasic response pattern during the progression of HBx tumorigenesis: a small peak at early phase and a large peak or terminal switch at the tumor phase. By analyzing cDNA microarray data, the early peak correlated to the oxidative stress and pro-inflammatory response, which then resolved at the middle phase and were followed by the terminal metabolic switch in the tumor tissues. Five lipid metabolism-related genes, the arachidonate 5-lipoxygenase, lipoprotein lipase, fatty acid binding protein 4, 1-acylglycerol-3-phosphate O-acyltransferase 9, and apolipoprotein A-IV were identified to be significantly activated in HBx transgenic HCCs and further validated in human HBV-related HCCs. Inhibition of these lipid genes could reverse the effect of HBx on lipid biosynthesis and suppress HBx-induced cell proliferation in vitro. Our results support the concept that metabolic syndrome plays an important role in HBV tumorigenesis. The dysregulation of lipid metabolic genes may predict the disease progression to HCC in chronic hepatitis B patients. © 2015 Wiley Periodicals, Inc.

The development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) has been found to be associated with disturbed lipid metabolism. To elucidate the role of lipid metabolism in HBV tumorigenesis, we investigated the dynamic pattern of lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis. Lipid and gene expression profiles were analyzed in an in vitro culture system and in transgenic mouse livers harboring HBV pre-S2 mutant. The pre-S2 mutant transgenic livers showed a biphasic pattern of lipid accumulation, starting from mild fatty change in early (1 month) transgenic livers, which subsided and then, remarkably, increased in HCC tissues. This biphasic pattern was synchronized with ATP citrate lyase (ACLY) activation. Further analyses revealed that the pre-S2 mutant initiated an endoplasmic reticulum (ER) stress-dependent mammalian target of rapamycin (mTOR) signalling cascade. The pre-S2 mutant-induced mTOR signal activated the sterol regulatory element binding transcription factor 1 (SREBF1) to upregulate ACLY, which then activated the fatty acid desaturase 2 (FADS2), mediated through ACLY-dependent histone acetylation. Such an ER stress-dependent mTOR signal cascade also is important for the proliferation of hepatocytes in vitro and is further validated in HBV-related HCC tissues. IMPORTANCE Aberrations of lipid metabolism frequently occur in chronic HBV infection. Our results provide a potential mechanism of disturbed lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis, which should be valuable for the design of HCC chemoprevention in high-risk HBV carriers.

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Pre-S2 mutant represents an HBV oncoprotein that is accumulated in the endoplasmic reticulum (ER) and manifests as type II ground glass hepatocytes (GGHs). Pre-S2 mutant can induce ER stress and initiate multiple ER stress-dependent or -independent cellular signal pathways, leading to growth advantage of type II GGH. Importantly, the mammalian target of rapamycin (mTOR) signal pathways are consistently activated throughout the liver tumorigenesis in pre-S2 mutant transgenic mice and in human HCC tissues, leading to hepatocyte proliferation, metabolic disorders, and HCC tumorigenesis. In this review, we summarize the pre-S2 mutant-induced mTOR signal pathways and its implications in HBV-related HCC tumorigenesis. Clinically, the presence of pre-S2 mutant exhibits a high resistance to antiviral treatment and carries a high risk of HCC development in patients with chronic HBV infection. Targeting at pre-S2 mutant-induced mTOR signal pathways may thus provide potential strategies for the prevention or therapy of HBV-associated HCC.