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Objective: The present research is aimed to elucidate the expression patterns of miR-424-5p and its role in tumorigenesis and progression of esophageal squamous cell carcinoma (ESCC). Methods: Both starBase and TCGA were utilized to assess miR-424-5p expression status in ESCC. The endogenous mRNA expression levels of miR-424-5p in ESCC and normal esophagus cell lines were detected by qRT-PCR. CCK8 and colony-forming assays were applied to determine the effects of miR-424-5p on ESCC proliferation. Transwell migration and wound healing assays were carried out to observe the changes of ESCC cell mobility after miR-424-5p mimic or inhibitor transfection. Impact of miR-424-5p on malignancy growth in vivo was further verified in a mouse xenograft model. The regulatory relationships between miR-424-5p and SIRT4 were validated by dual luciferase reporter assay, qRT-PCR and Western blot. Results: miR-424-5p expression was found upregulated in ESCC. miR-424-5p overexpression dramatically facilitated ESCC cells proliferation and migration capacity in vitro, while downregulation of miR-424-5p displayed the opposite trend. Inhibition of xenograft tumor growth was further evidenced in vivo. Moreover, SIRT4 was confirmed to be a specific target gene of miR-424-5p in ESCC and negatively modulated by miR-424-5p. Finally, SIRT4 overexpression strongly rescued the promoting influence of miR-424-5p on the proliferative and migratory capacity of ESCC cells. Conclusions: miR-424-5p had tumor promoting functions in proliferation and migration of ESCC by targeting SIRT4, suggesting that miR-424-5p may serve as a potential diagnostic biomarker and manipulation of miR-424-5p/SIRT4 axis could provide a novel therapeutic strategy for further ESCC treatment.

An emerging body of evidence has recently recognized the coexistence of epithelial-mesenchymal transition (EMT) and immune response. However, a systems-level view and survey of the interplay between EMT and immune escape program, and their impact on tumor behavior and clinical outcome across various types of cancer is lacking. Here, we performed comprehensive multi-omics analyses to characterize the landscape of crosstalk between EMT and immune evasion and their clinical relevance across 17 types of solid cancer. Our study showed the presence of complex and dynamic immunomodulatory crosstalk between EMT and immune evasion shared by pan-cancer, and the crosstalk was significantly associated with cancer prognosis and immunotherapy response. Integrative quantitative analyses of genomics and immunogenomics revealed that cellular composition of immune infiltrates, non-synonymous mutation burden, chromosomal instability and oncogenic gene alterations are associated with the balance between EMT and immune evasion. Finally, we proposed a scoring model termed EMT-CYT Index (ECI) to quantify the EMT-immunity axis, which was a superior predictor of prognosis and immunotherapy response across different malignancies. By providing a systematic overview of crosstalk between EMT and immune evasion, our study highlights the potential of pan-cancer EMT-immunity crosstalk as a paradigm for dissecting molecular mechanisms underlying cancer progression and guiding more effective and generalized immunotherapy strategies.

Purpose: As a main rate-limiting subunit of the 2-oxoglutarate dehydrogenase multienzyme complex, oxoglutarate dehydrogenase like (OGDHL) is involved in the tricarboxylic acid cycle, and frequently downregulated in human carcinoma and suppresses tumor growth. However, little is known about the role of OGDHL in human cancer, especially pancreatic cancer. Our goal is to study the underlying mechanism and define a novel signaling pathway controlled by OGDHL modulating pancreatic cancer progression. Experimental Design: The expression and functional analysis of OGDHL, miR-214, and TWIST1 in human pancreatic cancer tissues, cell lines, and xenograft tumor model were investigated. The correlations between OGDHL and those markers were analyzed. Results: OGDHL was downregulated in human pancreatic cancer and predicted poor prognosis. OGDHL overexpression inhibited migration and invasion of pancreatic cancer cells and suppressed pancreatic cancer tumor growth. OGDHL was shown to be negatively regulated by miR-214. TWIST1 upregulation induced miR-214 expression in pancreatic cancer. OGDHL suppressed TWIST1 expression through promoting ubiquitin-mediated proteasomal degradation of HIF1α and regulating AKT pathways. A combination of OGDHL downregulation and TWIST1 and miR-214 overexpression predicted worse prognosis in patients with pancreatic cancer. Conclusions: We demonstrated the prognostic value of OGDHL, miR-214, and TWIST1 in pancreatic cancer, and elucidated a novel pathway in OGDHL-regulated inhibition of pancreatic cancer tumorigenesis and metastasis. These findings may lead to new targeted therapy for pancreatic cancer through regulating OGDHL, miR-214, and TWIST1.

Recent evidence shows that cyclic GMP-AMP synthase (cGAS)/stimulator of interferon (IFN) genes (STING) signaling is essential for antitumor immunity by inducing the production of type I IFN and thus activating both innate and adaptive immunity based on gene knockout mouse models. However, the extensive detection of the expression of cGAS/STING signaling in human cancer and mining the roles of this signaling pathway in human cancer immunity have not been performed until now. In this study, we revealed that four key molecules (cGAS, STING, TANK binding kinase 1 [TBK1], and IFN regulatory factor 3 [IRF3]) in the cGAS/STING signaling are highly expressed in cancer tissues, and the expression levels of these genes are negatively correlated with their methylation levels in most of the detected cancer types. We also showed that highly upregulated cGAS/STING signaling is negatively correlated with the infiltration of immune cells in some tumor types, and consistent with these findings, we showed that a high level of cGAS/STING signaling predicts a poor prognosis in patients with certain cancers. This study suggests that it is necessary to deeply and fully evaluate the function of cGAS/STING signaling in cancer immunity and cancer progression before the application of the STING agonist-based anticancer immune therapy in the clinic., Graphical Abstract

Background Numerous studies have demonstrated that tetraspanin 1 (TSPAN1), a transmembrane protein, functions as an oncoprotein in many cancer types. However, its role and underlying molecular mechanism in cholangiocarcinoma (CCA) progression remain unclear. Methods In the present study, the expression of TSPAN1 in human CCA and adjacent nontumor tissues was examined using real-time PCR, western blot and immunohistochemistry. The effect of TSPAN1 on proliferation and metastasis was evaluated by functional assays both in vitro and in vivo. A luciferase reporter assay was performed to investigate the interaction between microRNA-194-5p (miR-194-5p) and TSPAN1 3′-untranslated region. Co-immunoprecipitation (co-IP) was used to confirm the interaction between TSPAN1 protein and integrin α6β1 and western blot was used to explore TSPAN1 mechanism. Results We found that TSPAN1 was frequently upregulated in CCA and high levels of TSPAN1 correlated with TNM stage, especially metastasis in CCA. TSPAN1 overexpression promoted CCA growth, metastasis, and induced epithelial-to-mesenchymal transition (EMT), while its silencing had the opposite effect both in vitro and in vivo. To explore the differential expression of TSPAN1, we screened miR-194-5p as the upstream regulator of TSPAN1. A combination of high-level TSPAN1 and low-level miR-194-5p predicted poor prognosis in patients with CCA. Furthermore, in accordance with the functional characteristics of the TSPAN superfamily, we proved that TSPAN1 interacted with integrin α6β1 to amplify the phosphoinositide-3-kinase (PI3K)/AKT/glycogen synthase kinase (GSK)-3β/Snail family transcriptional repressor (Snail)/phosphatase and tensin homolog (PTEN) feedback loop. Conclusion The results indicate that TSPAN1 could be a potential therapeutic target for CCA. Electronic supplementary material The online version of this article (10.1186/s13046-018-0969-y) contains supplementary material, which is available to authorized users.

The hypoxic microenvironment is beneficial to the metastasis but not to the proliferation of cancer cells. However, the mechanisms regarding to hypoxia differentially regulating cancer metastasis and proliferation are largely unknown. In this study, we revealed that hypoxia induced the expression of LIN28A at mRNA level but segregated LIN28A mRNAs in the P-bodies and thus inhibits the production of LIN28A protein. This unexpected finding suggests that there may be non-coding role for LIN28A mRNA in the progression of colon cancer. We further showed that the non-coding LIN28A mRNA promotes the metastasis but not proliferation of colon cancer cells in vitro and in vivo. Mechanistically, we revealed that methionyl aminopeptidase 2 (METAP2) is one of the up-regulated metastasis regulators upon over-expression of non-coding LIN28A identified by mass spectrum, and confirmed that it is non-coding LIN28A mRNA instead of LIN28A protein promotes the expression of METAP2. Moreover, we demonstrated that knockdown of DICER abolished the promotional effects of non-coding LIN28A on the metastasis and METAP2 expression. Conclusively, we showed that hypoxia induces the production of LIN28A mRNAs but segregated them into the P-bodies together with miRNAs targeting both LIN28A and METAP2, and then promotes the metastasis by positively regulating the expression of METAP2. This study uncovered a distinctive role of hypoxia in manipulating the metastasis and proliferation by differently regulating the expression of LIN28A at mRNA and protein level.

Purpose: Immunoscore was established to evaluate the prognosis of cancer patients. However, the feasibility of Immunoscore for the prognosis of cervical cancer remains unknown. To find other prognostic markers that contribute to immunological importance, immune checkpoint inhibitors targeting programmed cell death protein (PD-1), or its ligand, PD-L1, are of enormous interest. Our purpose is to investigate the expression of CD8 and PD-1/PD-L1 and their potential role in Immunoscore, supplementing the tumor/node/metastasis (TNM) classification of cervical cancer. Methods: Immunoscore was assessed according to the density of PD-1, PD-L1, and CD8 by immunohistochemistry. The association with overall survival and disease-free survival was assessed by the Kaplan–Meier method. To evaluate the effect of Immunoscore, a Cox proportional hazard regression classification was conducted. To compare the prognostic accuracies of Immunoscore and TNM staging, receiver operating characteristic curves were plotted. Results: Patients with PD-L1positive and PD-1high in immune cells had poorer overall survival and disease-free survival; however, PD-L1positive in tumor cells that infiltrated more CD8+ T cells were related to better overall survival and disease-free survival. These immune factors can be independent predictors for prognoses. According to these factors, a new Immunoscore system with priority in predicting prognoses was established. In receiver operating characteristic analysis for predictions of overall survival (the area under curve (AUC) = 0.833 vs. 0.766) and disease-free survival (AUC = 0.861 vs. 0.729), Immunoscore is more accurate than TNM staging. Conclusions: Thus, this Immunoscore system is an accurate predictive marker, which can be an important supplement to TNM staging for cervical cancer.

The aberrant appearance of DNA in the cytoplasm triggers the activation of cGAS-cGAMP-STING signaling and induces the production of type I interferons, which play critical roles in activating both innate and adaptive immune responses. Recently, numerous studies have shown that the activation of STING and the stimulation of type I IFN production are critical for the anticancer immune response. However, emerging evidence suggests that STING also regulates anticancer immunity in a type I IFN-independent manner. For instance, STING has been shown to induce cell death and facilitate the release of cancer cell antigens. Moreover, STING activation has been demonstrated to enhance cancer antigen presentation, contribute to the priming and activation of T cells, facilitate the trafficking and infiltration of T cells into tumors and promote the recognition and killing of cancer cells by T cells. In this review, we focus on STING and the cancer immune response, with particular attention to the roles of STING activation in the cancer-immunity cycle. Additionally, the negative effects of STING activation on the cancer immune response and non-immune roles of STING in cancer have also been discussed.

Despite impressive clinical success, cancer immunotherapy based on immune checkpoint blockade remains ineffective in colorectal cancer (CRC). Stimulator of interferon genes (STING) is a novel potential target and STING agonists have shown potential anti-tumor efficacy. Combined therapy based on synergistic mechanism can overcome the resistance. However, STING agonists-based combination therapies are deficient. We designed different immunotherapy combinations, including STING agonist, indoleamine 2,3 dioxygenase (IDO) inhibitor and PD-1 blockade, with purpose of exploring which option can effectively inhibit CRC growth. To further explore the possible reasons of therapeutic effectiveness, we observed the combination therapy in C57BL/6Tmem173gt mice. Our findings demonstrated that STING agonist diABZI combined with IDO inhibitor 1-MT significantly inhibited tumor growth, even better than the three-drug combination, promoted the recruitment of CD8+ T cells and dendritic cells, and decreased the infiltration of myeloid-derived suppressor cells. We conclude that diABZI combined with 1-MT is a promising option for CRC.

Although emerging studies showed that certain rhythm genes regulate cancer progression, the expression and roles of the vast majority of rhythm genes in human cancer are largely unknown, and the hallmarks of cancer regulated by rhythm genes have not been detected. In this study, we detected the expression changes of rhythm genes in pan‐cancer and found that almost all rhythm genes mutated in all cancer types, and their expression level was significantly altered partially due to abnormal methylation, and several rhythm genes regulate the expression of other rhythm genes in various cancer types. Furthermore, we revealed that rhythm genes are significantly enriched in genome instability and the expression of certain rhythm genes is correlated with the tumor mutation burden, microsatellite instability, and the expression of DNA damage repair genes in most of the detected cancer types. Moreover, rhythm genes are associated with the infiltration of immune cells and the efficiency of immune blockade therapy. This study provides a comprehensive understanding of the roles of rhythm genes in cancer immunity, which may provide a novel method for the diagnosis and treatment of cancer., We reported that almost all rhythm genes mutated in all cancer types, and their expression level was significantly altered partially due to abnormal methylation and a series of functions of rhythm genes in tumor development. Rhythm genes are associated with the infiltration of immune cells and the efficiency of immune blockade therapy. This study provides a comprehensive understanding of the roles of rhythm genes in cancer immunity, which may provide a novel method for the diagnosis and treatment of cancer.

Helicobacter pylori (HP) is a major causative agent of chronic gastritis and peptic ulcer. HP is also engaged in the development of gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. It is an important pathogenic factor in various other systemic diseases, such as vitamin B12 deficiency, iron deficiency, and idiopathic thrombocytopenia. The current consensus is that unless there is a special reason, eradication therapy should be implemented whenever HP infection is found, and it is ideally successful the first time. International guidelines recommend that under certain conditions, treatment should be personalized based on drug susceptibility testing. However, drug susceptibility testing is often not available because it is expensive, time-consuming, and difficult to obtain living tissue. Each region has separately formulated guidelines or consensuses on empirical therapy. Owing to an increasing drug resistance rate in various places, the eradication rate of proton pump inhibitor (PPI) triple therapy and sequential therapy has been affected. These regimens are rarely used; the PPI triple especially has been abandoned in most areas. Currently, radical treatment regimens for HP involve bismuth-containing quadruple therapy and concomitant therapy. However, quadruple therapy has its own limitations, such as complex drug administration. To improve the effectiveness, safety, and compliance, many clinical studies have proposed useful modified regimens, which mainly include the modified bismuth-containing quadruple regimen, high-dose dual therapy, and vonoprazan-containing regimens. Studies have shown that these emerging regimens have acceptable eradication rates and safety, and are expected to become first-line treatments in empirical therapy. However, the problem of decline in the eradication rate caused by drug resistance has not been fundamentally solved. This review not only summarizes the effectiveness of mainstream regimens in the first-line treatment of HP infection with the currently increasing antibiotic resistance rates, but also summarizes the effectiveness and safety of various emerging treatment regimens.

Increasing evidence supports a role for N-myc downstream-regulated gene 2 (NDRG2) deregulation in tumorigenesis. We investigated the roles and mechanisms of NDRG2 in human cholangiocarcinoma (CCA) progression. In the present study, expression of NDRG2, microRNA (miR)-181c and leukemia inhibitory factor (LIF) in human CCA and adjacent nontumor tissues were examined. The effects of NDRG2 on CCA tumor growth and metastasis were determined both in vivo and in vitro. The role of the NDRG2/LIF/miR-181c signaling pathway in cholangiocarcinogenesis and metastasis were investigated both in vivo and in vitro. The results showed that human CCA tissues exhibited decreased levels of NDRG2 and increased levels of miR-181c and LIF compared with nontumor tissues. NDRG2 could inhibit CCA cell proliferation, chemoresistance, and metastasis both in vitro and in vivo. We found that NDRG2 is a target gene of miR-181c, and the down-regulation of NDRG2 was attributed to miR-181c overexpression in CCA. Furthermore, miR-181c can be activated by LIF treatment, whereas NDRG2 could inhibit LIF transcription through disrupting the binding between Smad, small mothers against decapentaplegic complex and LIF promoter. Down-regulation of NDRG2 and overexpression of miR-181c or LIF are significantly associated with a poorer overall survival (OS) in CCA patients. Finally, we found that a combination of NDRG2, miR-181c, and LIF expression is a strong predictor of prognosis in CCA patients. Conclusion: These results establish the counteraction between NDRG2 and LIF/miR-181c as a key mechanism that regulates cholangiocarcinogenesis and metastasis. Our results elucidated a novel pathway in NDRG2-mediated inhibition of cholangiocarcinogenesis and metastasis and suggest new therapeutic targets, including NDRG2, LIF, miR-181c, and transforming growth factor beta, in CCA prevention and treatment. (Hepatology 2016;64:1606-1622)

Gankyrin plays important roles in tumorigenicity and metastasis of hepatocellular carcinoma (HCC). We have for the first time investigated the effects of Gankyrin on glycolysis and glutaminolysis both in vitro and in vivo, including in patient-derived xenografts. We reported Gankyrin increases glucose consumption, lactate production, glutamine consumption and glutamate production in HCC through upregulating the expression of the transporters and enzymes involved in glycolysis and glutaminolysis, including HK2, GLUT1, LDHA, PKM2, ASCT2 and GLS1. We further demonstrated that Gankyrin drives glycolysis and glutaminolysis through upregulating c-Myc via activating β-catenin signaling. Importantly, we found c-Myc mediated metabolic reprogramming might contribute to the tumorigenicity, metastasis and drug resistance induced by Gankyrin. c-Myc inhibitor synergizes with Sorafenib or Regorafenib to suppress HCC PDX tumors with high Gankyrin levels. We detected a significant correlation between Gankyrin and β-catenin expression levels in a cohort of HCC biopsies, and combination of these two parameters is a more powerful predictor of poor prognosis. Collectively, our results uncovered that Gankyrin functions as an essential regulator in glycolysis and glutaminolysis via activation of β-catenin/c-Myc to promotes tumorigenesis, metastasis and drug resistance in human HCC.

Background Abnormal metabolism, including abnormal lipid metabolism, is a hallmark of cancer cells. Some studies have demonstrated that the lipogenic pathway might promote the development of hepatocellular carcinoma (HCC). However, the role of the lipolytic pathway in HCC has not been elucidated. Methods We compared levels of adipose triglyceride lipase (ATGL) in human HCC and healthy liver tissues by real time PCR, western blot and immunohistochemistry. We measured diacylglycerol(DAG) and free fatty acid (FFA) levels in HCC cells driven by the NEAT1-ATGL axis and in HCC tissues. We also assessed the effects of ATGL, DAG, FFA, and NEAT1 on HCC cells proliferation in vitro and in an orthotopic xenograft HCC mouse model. We also performed a luciferase reporter assay to investigate the interaction between NEAT1/ATGL and miR-124-3p. Results We found that the lipolytic enzyme, ATGL is highly expressed in human HCC tissues and predicts poor prognosis. We also found that high levels of DAG and FFA are present in HCC tissues. Furthermore, the lncRNA-NEAT1 was found to modulate ATGL expression and disrupt lipolysis in HCC cells via ATGL. Notably, ATGL and its products, DAG and FFA, were shown to be responsible for NEAT1-mediated HCC cell growth. NEAT1 regulated ATGL expression by binding miR-124-3p. Additionally, NEAT1 knockdown attenuated HCC cell growth through miR-124-3p/ATGL/DAG+FFA/PPARα signaling. Conclusion Our results reveal that NEAT1-modulates abnormal lipolysis via ATGL to drive HCC proliferation. Electronic supplementary material The online version of this article (10.1186/s12943-018-0838-5) contains supplementary material, which is available to authorized users.

Hepatocellular carcinoma (HCC) is a lethal malignancy worldwide with frequent intrahepatic and distant metastasis. Elucidating the underlying molecular mechanism that modulates HCC progression is critical for exploring novel therapeutic strategies. Serine/Threonine Kinase 17B (STK17B) is upregulated in HCC tissues, but its role in HCC progression remains elusive. In the present studies, we reported that STK17B had a critical role in HCC progression. STK17B was significantly upregulated in HCC cell lines and specimens, and patients with ectopic STK17B expression characterized with poor clinicopathological features. In vitro and in vivo assay demonstrated that inhibition of STK17B markedly inhibits HCC tumorigenesis and metastasis, while STK17B overexpression promoted these processes. Furthermore, we found that STK17B promoted EMT process via activating AKT/GSK-3β/Snail signal pathway, and miR-455-3p was identified as the upstream regulator of STK17B. Combination of high level of STK17B and low level of miR-455-3p predicted poor prognosis with higher accuracy for HCC patients. In conclusion, our research demonstrated that STK17B promotes HCC progression, induces EMT process via activating AKT/GSK-3β/Snail signal and predicts poor prognosis in HCC.

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide. The poor survival may be due to a high proportions of tumor recurrence and metastasis. Kinesin family member C1 (KIFC1) is highly expressed in a variety of neoplasms and is a potential marker for non-small cell lung cancer or ovarian adenocarcinoma metastasis. Nevertheless, the role of KIFC1 in HCC metastasis remains obscure. We investigated this in the present study using HCC cell lines and clinical specimens. Our results indicated that increased levels of KIFC1 were associated with poor prognosis and metastasis in HCC. In addition, KIFC1 induced epithelial-to-mesenchymal transition (EMT) and HCC metastasis both in vitro and in vivo. This tumorigenic effect depended on gankyrin; inhibiting gankyrin activity reversed EMT via activation of protein kinase B (AKT)/Twist family BHLH transcription factor 1 (AKT/TWIST1). We also found that KIFC1 was directly regulated by the microRNA miR-532-3p, whose downregulation was associated with metastatic progression in HCC. These results denote that a decrease in miR-532-3p levels results in increased KIFC1 expression in HCC, leading to metastasis via activation of the gankyrin/AKT/TWIST1 signaling pathway.

Yes-associated protein (YAP), a transcriptional co-activator, has important regulatory roles in cell signaling and is dysregulated in a number of cancers. However, the role of YAP in cholangiocarcinoma (CCA) progression remains unclear. Here, we demonstrated that YAP was overexpressed in CCA cells and human specimens. High levels of nuclear YAP (nYAP) correlated with histological differentiation, TNM stage, metastasis and poor prognosis in CCA. Silencing YAP increased tumor sensitivity to chemotherapy and inhibited CCA tumorigenesis and metastasis both in vivo and in vitro. YAP overexpression in vivo and in vitro promoted CCA tumorigenesis and metastasis. Additionally, we found that YAP induced epithelial-mesenchymal transition (EMT) and formed a regulatory circuit with miR-29c, IGF1, AKT and gankyrin to promote the progression of CCA. Results of CCA tissue microarray showed positive correlations between nYAP and gankyrin or p-AKT expression. Combination of nYAP and gankyrin or p-AKT exhibited improved prognostic accuracy for CCA patients. In conclusion, YAP promotes carcinogenesis and metastasis by up-regulating gankyrin through activation of the AKT pathway.

Hepatocellular carcinoma (HCC) is a highly vascularized tumor with frequent extrahepatic metastasis. Active angiogenesis and metastasis are responsible for rapid recurrence and poor survival of HCC. However, the mechanisms that contribute to tumor metastasis remain unclear. Here we evaluate the effects of ATPase inhibitory factor 1 (IF1), an inhibitor of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase, on HCC angiogenesis and metastasis. We found that increased expression of IF1 in human HCC predicts poor survival and disease recurrence after surgery. Patients with HCC who have large tumors, with vascular invasion and metastasis, expressed high levels of IF1. Invasive tumors overexpressing IF1 were featured by active epithelial-mesenchymal transition (EMT) and increased angiogenesis, whereas silencing IF1 expression attenuated EMT and invasion of HCC cells. Mechanistically, IF1 promoted Snai1 and vascular endothelial growth factor (VEGF) expression by way of activating nuclear factor kappa B (NF-κB) signaling, which depended on the binding of tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) to NF-κB-inducing kinase (NIK) and the disruption of NIK association with the TRAF2-cIAP2 complex. Suppression of the NF-κB pathway interfered with IF1-mediated EMT and invasion. Chromatin immunoprecipitation assay showed that NF-κB can bind to the Snai1 promoter and trigger its transcription. IF1 was directly transcribed by NF-κB, thus forming a positive feedback signaling loop. There was a significant correlation between IF1 expression and pp65 levels in a cohort of HCC biopsies, and the combination of these two parameters was a more powerful predictor of poor prognosis. Conclusion: IF1 promotes HCC angiogenesis and metastasis by up-regulation of Snai1 and VEGF transcription, thereby providing new insight into HCC progression and IF1 function. (Hepatology 2014;60:1659–1673)

Here we showed that hepatocellular carcinoma (HCC) cell lines with high metastatic potential had low levels of NDRG2. The iron chelator Dp44mT up-regulated NDRG2, suppressed epithelial-mesenchymal transition (EMT) and inhibited tumor metastasis in HCC having high metastatic potential. Also Dp44mT attenuated the TGF-β1-induced EMT in HCC having low metastatic potential. In agreement, silencing endogenous NDRG2 with shNDRG2 in HCC cells attenuated the effect of Dp44mT. We showed that the NDRG2/gp130/STAT3 pathway can mediate Dp44mT effects. In agreement, we found that a combination of NDRG2 expression and p-STAT3 levels is a strong predictor of prognosis in HCC patients. We suggest that up-regulation of NDRG2 by Dp44mT is a promising therapeutic approach in HCC.

Although gankyrin is involved in the tumorigenicity and metastasis of some malignancies, the role of gankyrin in cholangiocarcinoma (CCA) is unclear. In this study we investigated the expression of gankyrin in human CCA tissues and cell lines. The effects of gankyrin on CCA tumor growth and metastasis were determined both in vivo and in vitro. The results showed that gankyrin was overexpressed in CCA tissues and cell lines. Gankyrin expression was associated with CCA histological differentiation, TNM stage, and metastasis. The multivariate Cox analysis revealed that gankyrin was an independent prognostic indicator for overall survival. Gankyrin overexpression promoted CCA cell proliferation, migration, and invasion, while gankyrin knockdown inhibited CCA tumor growth, metastasis, and induced Rb-dependent senescence and G1 phase cell cycle arrest. Gankyrin increased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and promoted the nuclear translocation of p-STAT3. Suppression of STAT3 signaling by small interfering RNA (siRNA) or STAT3 inhibitor interfered with gankyrin-mediated carcinogenesis and metastasis, while interleukin (IL)-6, a known upstream activator of STAT3, could restore the proliferation and migration of gankyrin-silenced CCA cells. The IL-6 level was decreased by gankyrin knockdown, while increased by gankyrin overexpression. Gankyrin regulated IL-6 expression by way of facilitating the phosphorylation of Rb; meanwhile, rIL-6 treatment increased the expression of gankyrin, suggesting that IL-6 was regulated by a positive feedback loop involving gankyrin in CCA. In the xenograft experiments, gankyrin overexpression accelerated tumor formation and increased tumor weight, whereas gankyrin knockdown showed the opposite effects. The in vivo spontaneous metastasis assay revealed that gankyrin promoted CCA metastasis through IL-6/STAT3 signaling pathway. Conclusion: Gankyrin is crucial for CCA carcinogenesis and metastasis by activating IL-6/STAT3 signaling pathway through down-regulating Rb protein. (Hepatology 2014;59:935–946)

Background Mounting epidemiological evidence supports a role for phosphatase and tensin homologue (PTEN)-T cell leukaemia 1 (Tcl1) signalling deregulation in hepatocarcinogenesis. Objective To determine the molecular and biochemical mechanisms by which the PTEN/Tcl1 axis regulates the pentose phosphate pathway (PPP) in hepatocellular carcinoma (HCC). Methods We compared levels of PTEN and glucose-6-phosphate dehydrogenase (G6PD) mRNA in human HCC and healthy liver tissue. We measured PPP flux, glucose consumption, lactate production, nicotinamide adenine dinucleotide phosphate (NADPH) levels and lipid accumulation. We investigated the PTEN/Tcl1 axis using molecular biology, biochemistry and mass spectrometry analysis. We assessed proliferation, apoptosis and senescence in cultured cells, and tumour formation in mice. Results We showed that PTEN inhibited the PPP pathway in human liver tumours. Through the PPP, PTEN suppressed glucose consumption and biosynthesis. Mechanistically, the PTEN protein bound to G6PD, the first and rate-limiting enzyme of the PPP and prevented the formation of the active G6PD dimer. Tcl1, a coactivator for Akt, reversed the effects of PTEN on biosynthesis. Tcl1 promoted G6PD activity and also increased G6PD pre-mRNA splicing and protein expression in a heterogeneous nuclear ribonucleoprotein (hnRNPK)-dependent manner. PTEN also formed a complex with hnRNPK, which inhibited G6PD pre-mRNA splicing. Moreover, PTEN inactivated Tcl1 via glycogen synthase kinase-3β (GSK3β)-mediated phosphorylation. Importantly, Tcl1 knockdown enhanced the sensitivity of HCC to sorafenib, whereas G6PD knockdown inhibited hepatocarcinogenesis. Conclusions These results establish the counteraction between PTEN and Tcl1 as a key mechanism that regulates the PPP and suggest that targeting the PTEN/Tcl1/hnRNPK/G6PD axis could open up possibilities for therapeutic intervention and improve the prognosis of patients with HCC.

Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has been reported to be a novel surgical technique that provides fast and effective growth of liver remnant. Despite occasional reports on animal studies, the mechanisms of rapid liver regeneration in ALPPS remains unclear. In the present study, we intend to develop a reproducible rat model to mimick ALPPS and to explore the underlying mechanisms. Rats assigned to the portal vein ligation (PVL), left lateral lobe (LLL) resection, transection and sham groups served as controls. Results indicated that the regeneration rate in the remnant liver after ALPPS was two times relative to PVL, whereas rats with transection alone showed minimal volume increase. The expression levels of Ki-67 and PCNA were about ten-fold higher after ALPPS compared with the transection and LLL resection groups and four-fold higher compared with the PVL group. The levels of TNF-α, IL-6 and HGF in the regenerating liver remnant were about three-fold higher after ALPPS than the controls. There was a more significant activation of NF-κB p65, STAT3 and Yap after ALPPS, suggesting synergistic activation of the pathways by PVL and transection, which might play an important role in liver regeneration after ALPPS.

Y. Liu, X. Zhang, Y. Liang, H. Yu, X. Chen, T. Zheng, B. Zheng, L. Wang, L. Zhao, C. Shi and S. Zhao (2011) Neuropathology and Applied Neurobiology37, 395–405 Targeting X box-binding protein-1 (XBP1) enhances sensitivity of glioma cells to oxidative stress Aims: Reactive oxygen species (ROS) and oxidative stress are tightly linked with cancers including gliomas. We previously reported the protective role of X box-binding protein-1 (XBP1) against oxidative stress in both mouse embryofibroblasts and human Hela cells. This study was to investigate XBP1-mediated protection against oxidative stress in the treatment of gliomas. Materials and methods: XBP1 expression levels were knocked down by siRNA transfection in the U251MG cell line. After exposure to hydrogen peroxide (H2O2) or the ROS inducer arsenic trioxide (As2O3), cell death, mitochondrial membrane potential (MMP) loss, ROS levels and the expression of several antioxidant molecules were examined. Expression of XBP1 and antioxidant molecules was also detected in surgically excised specimens from 30 patients with glioma, and 10 normal brain control specimens obtained at autopsy. Results: XBP1 knockdown significantly enhanced the cell death fraction, MMP loss and ROS levels in H2O2- or As2O3-treated glioma cells, concomitant with a decrease of several antioxidant molecules including catalase. Moreover, the abundant expression of XBP1 and antioxidant molecules was also observed in human glioma specimens, as compared with normal brain tissues. Conclusions: XBP1 confers an important role in protection against oxidative stress in gliomas, potentially via up-regulation of antioxidant molecules such as catalase. Targeting XBP1 may have synergistic effects with ROS inducers on glioma treatment.

The p53 family members, which consist of 3 transcription factors—p53, p63, and p73—are conserved during evolution. The p53 family proteins are involved in many important cellular functions, including tumor suppression (p53 and p73), the development of epithelial cell layers (p63), and the development of central nervous system and immune system (p73). Studies on p53-like proteins in low organisms have demonstrated that their primordial functions are to maintain the genomic integrity of germ cells and ensure faithful development and reproduction. In vertebrates, the p53 family proteins retain these functions in reproduction and at the same time have developed additional important functions in reproduction, such as the regulation of embryonic implantation (p53). p53 regulates embryonic implantation through transcriptional regulation of leukemia inhibitory factor (LIF). p63, in particular TAp63, is a main regulator to protect the fidelity of female germ cells during meiotic arrest. p73, in particular TAp73, regulates the ovary function and the quality of oocytes. Loss of p53, p63, or p73 genes in female mice leads to a significant decrease in fertility. These functions of the p53 family proteins in reproduction provide a plausible explanation for positive evolutionary selection observed in a group of single nucleotide polymorphisms and haplotypes in the p53 family genes. A better understanding of the functions of the p53 family proteins in reproduction may lead to new strategies for fertility treatment.

Hepatocellular carcinoma (HCC) is one of the most common malignancies and the third leading cause of cancer mortality world wide. Despite continuing development of new therapies, the prognosis for patients with HCC remains extremely poor. In part, this may relate to molecular abnormalities that stimulate HCC tumorigenesis and also contribute to reduced sensitivity to standard treatment. Increasing evidence has revealed the importance of liver cancer stem cells in hepatocarcinogenesis. Although widely investigated, the signaling pathways important for liver cancer stem cells in liver tumor initiation and progression are poorly understood. The Hippo signaling pathway was identified in Drosophila as an essential regulator of cell proliferation and apoptosis. Recently, Hippo pathway has been implicated in multiple events during development and it has also been proposed to play a vital role in several tumor types, especially in hepatocellular carcinoma. Strong evidences also proved the significant role of the Hippo signaling pathway in oval cell activation. As suggested, hippo signaling has a dual regulation of Hippo in liver tumor suppression as well as transition of oval cells to fully differentiated hepatocytes. Delineation of the malfunction of Hippo signaling pathway in HCC may lead to better understanding of hepatocarcinogenesis, rational medical therapy for HCC and possible therapy for other tumors. Here, we provide a historical review of this potent growth-regulatory pathway in HCC and highlight outstanding questions that will likely be the focus of future investigation.

Background and Aims: Nutlin-3, a selective small-molecule inhibitor of the p53-MDM2 interaction, has been shown to have antitumor activities in various tumors with wild-type p53. However, its effect on hepatocellular carcinoma (HCC) with different types of p53 remains unclear. This study is designed to determine nutlin-3′s antitumor efficacy and underlying mechanisms of action in human HCC cells. Methods: Cell viability assay, cell cycle analysis, apoptosis assay, western blot, co- immunoprecipitation and siRNA experiments were analyzed in three human HCC cells. Anti-tumoral effects of nutlin-3 targeting the p53 and p73 pathways were evaluated in HCC cell lines. Results: Nutlin-3 exerted the greatest anti-tumoral effect to three human HCC cells with wild-type p53, mutant p53 and p53-null. Nutlin-3 not only upregulated p53 in HepG2 cells, but also p73 in Huh7 and Hep3B cells, and disrupted p53-MDM2 and p73-MDM2 complexes in HCC cells. The compound inhibited cell proliferation, induced G0/G1 phase arrest, decreased the levels of CyclinD1, CyclinE, CDK2, CDK4, PCNA and E2F-1, and increased the levels of p21 and p27. It also induced apoptosis, increased the Bax/Bcl-2 ratio, then activated caspase-9 and caspase-3. Conclusions: Nutlin-3 has significant anticancer effects against human HCC cells, regardless of p53 status, indicating that it is a promising therapy for human hepatocellular carcinoma.

Background and Aim: More and more microRNA (miRNA) are found to be involved in tumor genesis and progress. Arsenic trioxide has been an effective chemotherapeutic drug in cancer therapy for many years. In this study, we aimed to find the miRNA involved in the mechanisms of arsenic trioxide treatment in cancer therapy. Methods: We detected the expression profile of miRNA by miRNA microarray and quantitative real-time polymerase chain reaction. Cell viability assay, flow cytometry analysis, prediction of miRNA targets, Western blot analysis and luciferase reporter assay were carried out to determine the role of one selected miRNA, namely mir-29a, in affecting the biological behaviors of HepG-2 cells. Results: Among the 677 human miRNA in the microarray, five miRNA were upregulated and four were downregulated in HepG-2 cells treated with arsenic trioxide compared to their controls. If only changes above two folds were considered, four miRNA were identified, namely miR-24, miR-29a, miR-30a and miR-210, which were all upregulated. Among them, miR-29a showed a positive therapeutic effect in liver cancer cells by inhibiting cell growth and inducing cell apoptosis, and PPM1D was confirmed to be the target gene of miR-29a. Furthermore, a synergy effect was detected between miR-29a and arsenic trioxide. Conclusions: Arsenic trioxide altered miRNA expression profile in HepG-2 cells. Among the altered miRNA, miR-29a seemed to take a role in the mechanism of arsenic trioxide in liver cancer therapy. The synergy effect between miR-29a and arsenic trioxide may offer this drug a new chance in cancer therapy by decreasing its dose and toxic side-effects.

FTY720, a new immunosuppressant, derived from ISP-1, has been studied for its putative anti-cancer properties in the recent years. In this study, we have reported that FTY720 greatly inhibited gastric cancer cell proliferation for the first time, and found this effect was associated with G1 phase cell cycle arrest and apoptosis. Results from our Western blotting and Real-time PCR showed that FTY720 induced obvious PTEN expression in a p53-independent way, consistent with a substantial decrease in p-Akt and MDM2. FTY720 dramatically increased the expression of Cip1/p21, p27, and BH3-only proteins through the accumulation of p53 by PTEN-mediated inhibition of the PI3K/Akt/MDM2 signaling. Suppression of PTEN expression with siRNA significantly reduced the p53 and p21 levels and activated Akt, resulting in decreased apoptosis and increased cell survival. Furthermore, we have observed an additive effect of FTY720 in killing gastric cancer cells when in combination with Cisplatin, partly through PTEN-mediated Akt/MDM2 inhibition. In vivo study has also shown that tumor growth was significantly suppressed after FTY720 treatment. In conclusion, our results suggest that FTY720 induces a significant increase of PTEN, which inhibits p-Akt and MDM2, and then increases the level of p53, thereby inducing G1 phase arrest and apoptosis. We have characterized a novel immunosuppressant, for the first time, which shows potential anti-tumor effects on gastric cancer by PTEN activation through p53-independent mechanism, especially in combination with Cisplatin. This PTEN target-based therapy is worth further investigation and warrants clinical evaluation.

Chemotherapy to date has not been effective in the treatment of cholangiocarcinoma. However, gemcitabine, a novel nucleoside analog, has shown remarkable biological activity against cholangiocarcinoma in some clinical studies. Combinations of gemcitabine with other agents have also shown promising results, with a tolerable toxicity profile. Nutlin-3 is a small-molecule inhibitor that acts to inhibit murine double minute-2 (MDM2) binding to p53 or p73 and subsequently activates p53- or p73-dependent apoptosis signaling pathways. To investigate their effects in combination, a p53-mutant cholangiocarcinoma line HuCCT1 was treated with Nutlin-3 and/or gemcitabine in the current study. Cell proliferation assay, apoptosis assay, Western blot, coimmunoprecipitation, and small interfering RNA (siRNA) experiments were analyzed in HuCCT1 cells. Antitumoral effects of Nutlin-3 and/or gemcitabine targeting the p73/MDM2 pathways were evaluated. Nutlin-3 and gemcitabine can both inhibit the growth of HuCCT1 cells. Nutlin-3 induces apoptosis and potentiates the cytotoxic effect of gemcitabine through disrupting the binding of p73 with MDM2. Nutlin-3 leads to activation of caspases, increase levels of puma and bax, and decrease the expression of bcl-2. Blocking p73 function with a siRNA attenuates the apoptosis induced by gemcitabine, Nutlin-3, and gemcitabine/Nutlin-3 combination. Our data provide evidence that p73 might compensate for p53 function in gemcitabine-induced apoptosis of HuCCT1 cells. Nutlin-3 acts through the inhibition of p73-MDM2 with subsequent activation of the apoptotic pathway signaling, which leads to the increase in chemosensitivity to gemcitabine. In summary, our findings suggest that Nutlin-3 will be active in the treatment of p53-mutant cholangiocarcinoma, especially when in combination with gemcitabine.

Despite recent advances in chemotherapeutic agents for Hepatocellular carcinoma (HCC) treatment, the results of chemotherapy remain unsatisfactory. Doxorubicin (DOX) still represents the cornerstone in HCC chemotherapy, but resistance and toxicity to normal cells are major obstacles to successful chemotherapy. Therefore, new active agents in HCC chemotherapy and agents that increase the chemosensitivity of HCC cells to DOX are still urgently required. Nutlin-3 is a small-molecule inhibitor that acts to inhibit murine double minute-2 (MDM2) binding to p53 or p73, and subsequently activates p53- or p73-dependent apoptosis signaling pathway. This study was designed to investigate whether Nutlin-3 alters cell toxicity to HCC cells following DNA damage and to assess the suitability of DOX/Nutlin-3 as a chemotherapeutic combination in HCC chemotherapy.Four human HCC cells were analyzed using cell proliferation assay, apoptosis assay, western blotting, co-immunoprecipitation and siRNA experiments. Anti-tumoral effects of Nutlin-3/DOX targeting the p53/MDM2 and p73/MDM2 pathways were evaluated in HCC cell lines.Nutlin-3 enhances the growth inhibition by DOX and potentates the apoptotic effect in all HCC cell lines with different p53 types. Nutlin-3 acts through the disruption of p53-MDM2 binding in HepG2, and the disruption of p73-MDM2 in Huh-7 and Hep3B cell lines with subsequent activation of the apoptotic pathway, which leads to the increase in chemosensitivity to DOX in HCC cells.Taken together, our findings suggest that Nutlin-3 will be active in the treatment of HCC and offers new prospects for overcoming DOX resistance.

Chemotherapy has been widely used in treatment of cancer, both as systemic therapy and as part of local treatment. Unfortunately, many kinds of cancer are still refractory to chemotherapy. The anticancer drug resistance mechanisms have been extensively explored, yet have not been fully characterized. Recent works have underlined the involvement of noncoding RNAs in cancer development, with several studies regarding their possible involvement in the evolution of drug resistance. MicroRNAs (miRNAs) are endogenous small noncoding RNAs (20-23 nucleotides) that negatively regulate the gene expressions at the post-transcriptional level by base pairing to the 3' untranslated region of target messenger RNAs. Evidence is emerging that particular microRNAs (miRNA) alterations are involved in the initiation and progression of human cancer. More recently, accumulating evidence is revealing an important role of miRNAs in anticancer drug resistance and miRNA expression profiling can be correlated with the development of anticancer drug resistance. The micro-RNA-mediated form of drug resistance adds yet another mechanism of drug resistance. So, exploiting the emerging knowledge of miRNAs for the development of new human therapeutic applications for overcoming anticancer drug resistance will be important.

Tumor suppressor p53 is the most frequently mutated gene in tumors. Many mutant p53 (mutp53) proteins promote tumorigenesis through the gain-of-function (GOF) mechanism. Mutp53 proteins often accumulate to high levels in tumors, which is critical for mutp53 GOF. Its underlying mechanism is poorly understood. Here, we found that BAG2, a protein of Bcl-2 associated athanogene (BAG) family, promotes mutp53 accumulation and GOF in tumors. Mechanistically, BAG2 binds to mutp53 and translocates to the nucleus to inhibit the MDM2-mutp53 interaction, and MDM2-mediated ubiquitination and degradation of mutp53. Thus, BAG2 promotes mutp53 accumulation and GOF in tumor growth, metastasis and chemoresistance. BAG2 is frequently overexpressed in tumors. BAG2 overexpression is associated with poor prognosis in patients and mutp53 accumulation in tumors. These findings revealed a novel and important mechanism for mutp53 accumulation and GOF in tumors, and also uncovered an important role of BAG2 in tumorigenesis through promoting mutp53 accumulation and GOF. DOI: http://dx.doi.org/10.7554/eLife.08401.001, eLife digest Cancer can develop if cells in the body acquire mutations that enable them to grow rapidly to form a mass called a tumor. The gene that encodes a protein called p53 is the most commonly mutated gene in human tumors. Most of these mutations result in the production of mutant p53 proteins that are similar in size to the normal protein, but do not work in the same way. The normal p53 protein is known as a ‘tumor suppressor’ because it promotes the repair of damaged genetic material and stops the cell from dividing while this repair is underway. Also, it can instruct a cell to die if the damage is too great to repair. However, many of the mutant p53 proteins stop performing these roles and gain new activities that promote tumor growth instead. These activities often rely on the mutant p53 proteins accumulating to very high levels, but it is not clear why this happens. Here, Yue, Zhao et al. used biochemical techniques to search for other proteins that can bind to mutant p53 proteins. The experiments reveal that a protein called BAG2 binds to mutant p53 and promotes its accumulation in cancer cells, which increases the activity of mutant p53 in driving tumor growth. Loss of BAG2 leads to a reduction in the level of mutant p53 in cells and inhibits the activity of mutant p53. Using a public database of genetic data from human tumors, Yue, Zhao et al. found that human tumor cells often contain higher levels of BAG2 than normal cells. Furthermore, patients with tumors that had high levels of BAG2—and therefore accumulated mutant p53 proteins—were less likely to have positive outcomes after medical treatment. Yue, Zhao et al.'s findings suggest that increased production of BAG2 in many tumors may be responsible for the accumulation of mutant p53 proteins that drive tumor growth. A future goal is to develop a new treatment strategy that targets BAG2 in tumors to prevent the accumulation of mutant p53 proteins and therefore block the growth of tumors. DOI: http://dx.doi.org/10.7554/eLife.08401.002

Background Interleukin 6 (IL-6)-mediated signal transducers and activators of transcription 3 (STAT-3) phosphorylation (activation) is aberrantly sustained in cholangiocarcinoma cells resulting in enhanced myeloid cell leukemia 1 (Mcl-1) expression and resistance to apoptosis. FTY720, a new immunosuppressant, derived from ISP-1, has been studied for its putative anti-cancer properties. This study aimed to elucidate the mechanism by which FTY720 mediates antitumor effects in cholangiocarcinoma (CC) cells. Methods Three CC cell lines were examined, QBC939, TFK-1, and HuCCT1. The therapeutic effects of FTY720 were evaluated in vitro and in vivo. Cell proliferation, apoptosis, cell cycle, invasive potential, and epithelial- mesenchy-mal transition (EMT) were examined. Results FTY720 greatly inhibited CC cells proliferation and EMT in vitro and in vivo, and this effect was associated with dephosphorylation of STAT3tyr705. FTY720 induced apoptosis and G1 phase arrest in CC cells, and inhibited invasion of CC cells. Western blot analysis showed that FTY720 induced cleavage of caspases 3, 8 and 9, and of PARP, in a dose-dependent manner, consistent with a substantial decrease in p-STAT3, Bcl-xL, Bcl-2, survivin, cyclin D1, cyclin E, N-cadherin, vimentin, VEGF and TWIST1. In vivo studies showed that tumor growth and metastasis were significantly suppressed after FTY720 treatment. Conclusions These results suggest that FTY720 induces a significant decrease in p-STAT3, which inhibits proliferation and EMT of CC cells, and then induces G1 phase arrest and apoptosis. We have characterized a novel immunosuppressant, which shows potential anti-tumor effects on CC via p-STAT3 inhibition. FTY720 merits further investigation and warrants clinical evaluation. Electronic supplementary material The online version of this article (doi:10.1186/1471-2407-14-783) contains supplementary material, which is available to authorized users.

Background Gankyrin has shown to be overexpressed in human liver cancers and plays a complex role in hepatocarcinogenesis. Panobinostat (LBH589), a new hydroxamic acid-derived histone deacetylase inhibitor has shown promising anticancer effects recently. Here, we investigated the potential of LBH589 as a form of treatment for hepatocellular carcinoma (HCC). Methods Gankyrin plasmid was transfected into HCC cells, and the cells were selected for more than 4 weeks by incubation with G418 for overexpression clones. The therapeutic effects of LBH589 were evaluated in vitro and in vivo. Cell proliferation, apoptosis, cell cycle, invasive potential, and epithelial-mesenchy-mal transition (EMT) were examined. Results LBH589 significantly inhibited HCC growth and metastasis in vitro and in vivo. Western blotting analysis indicated that LBH589 could decrease the expression of gankyrin and subsequently reduced serine-phosphorylated Akt and tyrosine-phosphorylated STAT3 expression although the total Akt and STAT3 were unaffected. LBH589 inhibited metastasis in vitro via down-regulation of N-cadherin, vimentin, TWIST1, VEGF and up-regulation of E-cadherin. LBH589 also induced apoptosis and G1 phase arrest in HCC cell lines. Ectopic expression of gankyrin attenuated the effects of LBH589, which indicates that gankyrin might play an important role in LBH589 mediated anticancer effects. Lastly, in vivo study indicated that LBH589 inhibited tumor growth and metastasis, without discernable adverse effects comparing to control group, with abrogating gankyrin/STAT3/Akt pathway. Conclusions Our results suggested that LBH589 could inhibit HCC growth and metastasis through down-regulating gankyrin/STAT3/Akt pathway. LBH589 may present itself as a novel therapeutic strategy for HCC.

Cholangiocarcinoma (CCA) is a type of digestive tumor that is associated with a high rate of mortality due to the difficulty of early diagnosis and the resistance of this tumor type to chemotherapy. Hydroxytyrosol (HT), which is derived from virgin olive oil (VOO), has recently been reported to inhibit the proliferation of various types of human cancer cells. In the present study, we investigated the effect of HT on CCA. The antiproliferative and proapoptotic effects of HT on CCA were evaluated in the human CCA cell lines TFK-1 and KMBC and the human gallbladder cancer cell line GBS-SD. We also assessed this effect in vivo. We found that 75 µM HT inhibited the proliferation of the TFK-1, KMBC and GBS-SD cell lines. However, 200 µM HT treatment did not affect the proliferation of the human bile duct cell line HIBEpiC. More importantly, HT (250 and 500 mg/kg/day) markedly inhibited the growth of CCA xenografts in mice. G2/M phase cell cycle arrest and apoptosis were observed using flow cytometry and western blotting, and we also noted a time- and dose-dependent inhibition of phospho-ERK, with no changes in total-ERK, during treatment with HT. The present study showed that HT induces cell cycle arrest and apoptosis in vitro and in vivo. These data suggest that HT, which possesses excellent biocompatibility and few side-effects, could be developed as a novel agent against CCA.

The increasing incidence of hepatocellular carcinoma (HCC) is of great concern not only in the United States but throughout the world. Although sorafenib, a multikinase inhibitor with antiangiogenic and antiproliferative effects, currently sets the new standard for advanced HCC, tumor response rates are usually quite low. An understanding of the underlying mechanisms for sorafenib resistance is critical if outcomes are to be improved. In this study we tested the hypothesis that hypoxia caused by the antiangiogenic effects of sustained sorafenib therapy could induce sorafenib resistance as a cytoprotective adaptive response, thereby limiting sorafenib efficiency. We found that HCCs, clinically resistant to sorafenib, exhibit increased intratumor hypoxia compared with HCCs before treatment or HCCs sensitive to sorafenib. Hypoxia protected HCC cells against sorafenib and hypoxia-inducible factor 1 (HIF-1α) was required for the process. HCC cells acquired increased P-gp expression, enhanced glycolytic metabolism, and increased nuclear factor kappa B (NF-κB) activity under hypoxia. EF24, a molecule having structural similarity to curcumin, could synergistically enhance the antitumor effects of sorafenib and overcome sorafenib resistance through inhibiting HIF-1α by sequestering it in cytoplasm and promoting degradation by way of up-regulating Von Hippel-Lindau tumor suppressor (VHL). Furthermore, we found that sustained sorafenib therapy led to increased intratumor hypoxia, which was associated with sorafenib sensitivity in HCC subcutaneous mice tumor models. The combination of EF24 and sorafenib showed synergistically effects against metastasis both in vivo and in vitro. Synergistic tumor growth inhibition effects were also observed in subcutaneous and orthotopic hepatic tumors. Conclusion: Hypoxia induced by sustained sorafenib treatment confers sorafenib resistance to HCC through HIF-1α and NF-κB activation. EF24 overcomes sorafenib resistance through VHL-dependent HIF-1α degradation and NF-κB inactivation. EF24 in combination with sorafenib represents a promising strategy for HCC. (HEPATOLOGY 2013)

Epidemiological studies strongly suggest that chronic psychological stress promotes tumorigenesis. However, its direct link in vivo and the underlying mechanisms that cause this remain unclear. This study provides direct evidence that chronic stress promotes tumorigenesis in vivo; chronic restraint, a well-established mouse model to induce chronic stress, greatly promotes ionizing radiation (IR)-induced tumorigenesis in p53 +/− mice. The tumor suppressor protein p53 plays a central role in tumor prevention. Loss or attenuation of p53 function contriubutes greatly to tumorigenesis. We found that chronic restraint decreases the levels and function of p53 in mice, and furthermore, promotes the growth of human xenograft tumors in a largely p53-dependent manner. Our results show that glucocorticoids elevated during chronic restraint mediate the effect of chronic restraint on p53 through the induction of serum- and glucocorticoid-induced protein kinase (SGK1), which in turn increases MDM2 activity and decreases p53 function. Taken together, this study demonstrates that chronic stress promotes tumorigenesis in mice, and the attenuation of p53 function is an important part of the underlying mechanism, which can be mediated by glucocortcoids elevated during chronic restraint.

Tumor suppressor p53 plays a crucial role in preventing tumor formation. p53 responds to stress signals and transcriptionally regulates its target genes to start various cellular responses, thus preventing tumor initiation and/or progression. p53 is the most frequently-mutated gene in tumors; approximately 50% of human tumors harbor inactivating mutations in p53. The p53 protein is under tight regulation in cells. Loss or the attenuation of p53 function affects cancer risk and tumor progression. Epidemiological studies strongly suggest that chronic psychological stress has negative influences on the onset, progression and mortality of cancers. Studies employing chronic restraint or social isolation in mice, two well-established chronic stress models, have shown that chronic stress enhances tumor growth and metastasis in xenograft tumor assays. However, the direct evidence that chronic stress promotes tumorigenesis in vivo is still lacking, and furthermore, the molecular mechanisms by which chronic stress promotes tumorigenesis remain unclear. To investigate the impact of chronic stress upon tumorigenesis in vivo, we established a mouse model that combines chronic restraint and ionizing radiation (IR)-induced tumorigenesis. IR induces tumorigenesis in both mice and humans. p53+/- mice are susceptible to IR-induced tumorigenesis; a single dose of 4 Gy IR results in the development of tumors, mainly lymphomas, in p53+/- mice. By employing this mouse model system, we found that in p53+/- C57BL6/J mice, chronic restraint stress greatly promoted IR-induced tumorigenesis; chronic restraint reduced IR-induced tumor latency from ∼49 weeks to ∼38 weeks of median survival age (p=0.004). This result provides direct evidence that chronic stress enhances tumorigenesis in vivo. Furthermore, chronic restraint decreased p53 protein levels and function in mice, and promoted the growth of human xenograft tumors in a largely p53-dependent manner. Chronic restraint greatly promotes the growth rate of HCT116 p53+/+ tumors (increased by 3.77-fold) in mice; and has significantly less pronounced promoting effect on the growth of HCT116 p53-/- tumors (increased by 1.52-fold) (p Citation Format: Cen Zhang, Meihua Lin, Yuhan Zhao, Tongsen Zheng, Jiabei Wang, Arnold Levine, Zhaohui Feng, Wenwei Hu. Chronic stress promotes tumorigenesis through attenuation of p53 function . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 784. doi:10.1158/1538-7445.AM2013-784

Tumor suppressor p53 is frequently mutated in tumors. Mutant p53 (Mutp53) proteins often gain new activities in promoting tumorigenesis, defined as gain-of-function (GOF). Mutp53 often accumulates at high levels in tumors, which promotes mutp53 GOF in tumorigenesis. The mechanism of mutp53 accumulation is poorly understood. Here we find that MDM2 isoforms promote mutp53 accumulation in tumors. MDM2 isoform B (MDM2-B), the MDM2 isoform most frequently over-expressed in human tumors, interacts with full-length MDM2 to inhibit MDM2-mediated mutp53 degradation, promoting mutp53 accumulation and GOF in tumorigenesis. Furthermore, MDM2-B over-expression correlates with mutp53 accumulation in human tumors. In mutp53 knock-in mice, a MDM2 isoform similar to human MDM2-B is over-expressed in the majority of tumors, which promotes mutp53 accumulation and tumorigenesis. Thus, over-expression of MDM2 isoforms promotes mutp53 accumulation in tumors, contributing to mutp53 GOF in tumorigenesis. Furthermore, promoting mutp53 accumulation and GOF is an important mechanism by which MDM2 isoforms promote tumorigenesis.