DLAT as a Cuproptosis Promoter and a Molecular Target of Elesclomol in Hepatocellular Carcinoma.

OBJECTIVE: Cuproptosis is a novel cell death pathway that was newly discovered in early 2022. However, cuproptosis is still in its infancy in many respects and warrants further research in hepatocellular carcinoma (HCC). This study aimed to analyze the mechanism of cuprptosis in HCC. METHODS: Herein, the tumor microenvironment infiltration landscape of molecular subtypes was illustrated using GSVA, ssGSEA, TIMER, CIBERSORT, and ESTIMATE algorithms based on the expression profile of cuproptosis-related genes (CRGs) from TCGA and GEO databases. Then, the least absolute shrinkage and selection operator regression method was applied to construct a cuproptosis signature to quantify the cuproptosis profile of HCC. Further, we explored the expression of three hub CRGs in cell lines and clinical patient tissues of HCC by Western blotting, qRT-PCR and immunohistochemistry. Finally, we examined the function of dihydrolipoamide S-acetyltransferase (DLAT) in cuproptosis in HCC by loss-of-function strategy, Western blotting and CCK8 assay. RESULTS: Three distinct molecular subtypes were identified. Cluster 2 had the greatest infiltration of immune cells with best prognosis. The cuproptosis signature was indicative of tumor subtype, immunity, and prognosis for HCC, and specifically, a low cuproptosis score foreshadowed good prognosis. DLAT was highly expressed in liver cancer cell lines and HCC tissues and positively correlated with clinical stage and grade. We also found that potent copper ionophore elesclomol could induce cuproptosis in a copper-dependent manner. Selective Cu++ chelator ammonium tetrathiomolybdate and downregulating DLAT expression by siRNA could effectively inhibit cuproptosis. CONCLUSION: Cuproptosis and DLAT as a promising biomarker could help to determine the prognosis of HCC and may offer novel insights for effective treatment.

Impact of body size on efficacy of high-dose dual therapy for Helicobacter pylori eradication.

BACKGROUND: High-dose dual therapy (HDDT) is an emerging and promising therapeutic regime for Helicobacter pylori (H. pylori) eradication. However, the pharmacokinetics of the components of HDDT, amoxicillin and proton pump inhibitor, are likely to be affected by body size. In this study, we aimed to find out the impact of body size on the efficacy of HDDT. METHODS: We collected the medical data of 385 treatment-naive patients infected with H. pylori who received HDDT (esomeprazole 20 mg and amoxicillin 750 mg four times daily) for 14 days from July 2020 to December 2021. The associations among the eradication efficacy, adverse events, and variables (sex, age, height, body weight, body mass index (BMI), body surface area (BSA), smoking, drinking, etc.) were analyzed respectively in our study. Among these factors, continuous variables were classified into categorical variables using the cut-off values which were calculated by receiver operating characteristic analysis. RESULTS: The eradication rate of HDDT was 89.9%. There were 55 (14.3%) patients who occurred adverse events during the treatment. Patients with height <170.5 cm, body weight <60.5 kg, BMI <20.55 kg/m2 , BSA <1.69 m2 had a higher eradication rate (92.1% vs. 84.0%, 93.1% vs. 86.8%, 96.0% vs. 87.8%, 93.4% vs. 84.8%, all p < .05). The multivariate analysis showed that BSA ≥1.69 m2 (OR 2.53, 95% CI: 1.28-4.99, p = .007) was the only independent predictor of eradication failure. CONCLUSION: HDDT could achieve better eradication efficacy in patients with small BSA. Clinicians should be aware of the impact of BSA on the H. pylori eradication rate and pay more attention to patients with large BSA.

Urgent Endoscopy in Nonvariceal Upper Gastrointestinal Hemorrhage: A Retrospective Analysis.

OBJECTIVE: The role of urgent endoscopy in nonvariceal upper gastrointestinal hemorrhage (NVUGIH) remains controversial. We designed a retrospective study to compare the outcomes between urgent endoscopy (within 12 h) and non-urgent endoscopy for patients with NVUGIH. METHODS: A total of 540 hospitalized patients with NVUGIH were included in our study. Patients who received endoscopy within 12 h or after 12 h were divided into two groups, the urgent and non-urgent endoscopy groups, respectively. The clinical outcomes including rebleeding, mortality, endoscopic re-intervention, need for emergency surgery and interventional radiotherapy were compared between the groups. Patients with Glasgow-Blatchford scores (GBS) <12 and ≥12 were defined as the lower- and high-risk groups, respectively, and the predictors of rebleeding and mortality in both groups were analyzed individually. RESULTS: Patients with NVUGIH in the urgent endoscopy group had a higher rate of rebleeding (27.6% vs. 16.9%, P=0.003) and blood transfusion (73.2% vs. 55.5%, P<0.001) than those in the non-urgent endoscopy group, while the mortality and the length of hospitalization were not significantly different between the groups (P>0.05). For lower-risk patients, urgent endoscopy was independently associated with a higher likelihood of rebleeding (adjusted OR: 1.73, 95% CI: 1.03-2.88), while it was not associated with in-hospital mortality. However, the urgent need for endoscopy was not associated with rebleeding and inhospital mortality in high-risk patients. CONCLUSION: Endoscopy within 12 h did not provide any advantage in the outcomes of patients with NVUGIH, and may even lead to an increased rebleeding rate in lower-risk patients.

Does off-hours endoscopic hemostasis affect outcomes of nonvariceal upper gastrointestinal bleeding?

Aim: Different researches showed controversial results about the 'off-hours effect' in nonvariceal upper gastrointestinal bleeding (NVUGIB). Materials & methods: A total of 301 patients with NVUGIB were divided into regular-hours group and off-hours group based on when they received endoscopic hemostasis, and the relationship of the clinical outcomes with off-hours endoscopic hemostasis was evaluated. Results: Patients who received off-hours endoscopy were sicker and more likely to experience worse clinical outcomes. Off-hours endoscopic hemostasis was a significant predictor of the composite outcome in higher-risk patients (adjusted OR: 4.63; 95% CI: 1.35-15.90). However, it did not associate with the outcomes in lower-risk patients. Conclusion: Off-hours effect may affect outcomes of higher-risk NVUGIB patients receiving endoscopic hemostasis (GBS ≥12).

Bromodomain-containing protein 9 promotes hepatocellular carcinoma progression via activating the Wnt/ß-catenin signaling pathway.

BACKGROUND: Epigenetic dysregulation participates in the initiation and progression of hepatocellular carcinoma (HCC). Bromodomain-containing protein 9 (BRD9) can identify acetylated lysine residues, contributing to several cancers. The function and molecular mechanism of BRD9 in HCC remain poorly understood. METHODS: BRD9 levels in tissues and cells of HCC and normal liver were evaluated using bioinformatic analysis, real-time PCR, and western blot. BRD9's association with clinical outcomes was investigated via survival analyses. Biological behaviors and pathways related to BRD9 were predicted using gene set enrichment analysis. BRD9's role in proliferation was verified via cell counting kit 8, colony formation, and 5-Ethynyl-2'-deoxyuridine assays. Its role in the cell cycle and apoptosis was assessed using flow cytometry. The role of BRD9 in vivo was investigated using xenograft tumor models. A rescue assay was performed to investigate the molecular mechanism of BRD9. RESULTS: BRD9 was markedly upregulated in HCC and higher BRD9 expression was associated with higher grade, advanced stage, greater tumor size, and poorer prognosis. BRD9 overexpression enhanced cell proliferation, cell cycle progress, but impeded cell apoptosis. BRD9 downregulation had the opposite effects. In vivo, BRD9 promoted xenograft tumor growth. Mechanistically, BRD9 activated Wnt/ß-catenin signaling, obstruction of which abrogated BRD9-mediated tumorigenesis. CONCLUSION: Increased BRD9 in HCC correlated with poor prognosis, which functioned via activating Wnt/ß-catenin signaling. Thus, BRD9 might be a promising biomarker and therapeutic target for patients with HCC.

LncRNA NBR2 inhibits tumorigenesis by regulating autophagy in hepatocellular carcinoma.

Long noncoding RNAs (lncRNAs) have been identified to play increasingly important roles in tumorigenesis, and they may serve as novel biomarkers for cancer therapy. LncRNA NBR2 (neighbor of BRCA1 gene 2), a novel identified lncRNA, is demonstrated to decrease in several cancers. However, it is still unknown whether lncRNA NBR2 is involved in hepatocellular carcinoma and autophagy. We found that HCC cases with lower NBR2 expression had significantly worse overall survival than those with higher NBR2 expression in advanced patients. And the expression of NBR2 was negatively correlated with the degree of malignancy of HCC cell lines and differentiation of hepatocellular carcinoma. Besides, NBR2 inhibited the proliferation, invasion, and migration of liver cancer cells. We further found that NBR2 repressed cytoprotective autophagy to restrain HCC cell proliferation. Moreover, NBR2 inhibited Beclin 1-dependent autophagy through ERK and JNK pathways. Taken together, NBR2 suppressed autophagy-induced cell proliferation at least partly through ERK and JNK pathways. These data indicated that NBR2 served as a tumor suppressor gene in hepatocellular carcinoma. The current study provides a novel insight and treatment strategy for hepatocellular carcinoma.

Long non-coding RNA LINC01503 promotes the progression of hepatocellular carcinoma via activating MAPK/ERK pathway.

Background: Increasing evidence has implicated that lncRNAs (long non-coding RNAs) play significant roles in carcinogenesis and progression of HCC (hepatocellular carcinoma). LINC01503 is a new lncRNA related to several tumors. Nonetheless, its role in HCC still remains unclear. Methods: The expression levels of LINC01503 in HCC, normal liver tissues as well as HCC cell lines were evaluated by TCGA (The Cancer Genome Atlas) and real-time PCR assay, respectively. The relationship between LINC01503 levels and the prognosis of patients with HCC was evaluated using Kaplan-Meier survival analysis. Then the potential biological functions and pathways related to LINC01503 were investigated by GO (Gene Ontology) analysis and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, and GSEA v4.0.1 software was employed. Furthermore, the influence of LINC01503 on the proliferation and apoptosis of HCC cells was confirmed using CCK8 assay, flow cytometry, and clone formation assay in cell experiments. Also the pro-tumor effect of LINC01503 was verified by mice xenograft experiment in vivo. In addition, the functional pathway of LINC01503 was proved by western blot and rescue experiments. Results: LINC01503 was highly expressed in HCC and positively correlated with large tumor size, high tumor grade, advanced tumor stage, and poor prognosis of HCC patients. Silencing LINC01503 with shRNA significantly restrained the proliferation of MHCC-97H HCC cells and strengthened the apoptosis, while up-regulation of LINC01503 in Huh7 HCC cells contributed to the contrary effects. Besides, LINC01503 promoted tumor growth of nude mice transplanted with liver cancer cells. Mechanistically, MAPK/ERK signaling pathway was activated by LINC01503, inhibition of which could alleviate the pro-tumor effect of LINC01503, consistent with the forecast of GSEA (Gene Set Enrichment Analysis). Conclusion: LINC01503 is highly expressed in HCC and promotes the progression of HCC via MAPK/ERK pathway, which maybe a new potential biomarker and therapeutic target for HCC.

Astrocyte elevated gene 1 (AEG-1) promotes anoikis resistance and metastasis by inducing autophagy in hepatocellular carcinoma.

Astrocyte elevated gene 1 (AEG-1) is overexpressed in hepatocellular carcinoma (HCC) and is strongly associated with tumor metastasis. Anoikis resistance and autophagy may play an important role in the survival of circulating tumor cells. However, the relationship among AEG-1, anoikis resistance, autophagy, and metastasis in HCC is still not clear. The results of this study indicate that AEG-1 expression is increased in HCC cell lines grown in suspension culture. AEG-1 could enhance anoikis resistance to promote the survival of detached HCC cells. Moreover, the anoikis resistance appears to be partly dependent on autophagy. Regulating AEG-1 expression changed the autophagy levels to modulate anoikis resistance, likely acting via the protein kinase RNA-like ER kinase (PERK)-eIF2α-ATF4-CHOP signaling axis. Finally, inhibiting autophagy by RNA interference prevented the AEG-1-promoted metastasis of HCC xenografts to the liver and lungs of nude mice. Taken together, AEG-1 is a key contributor to anoikis resistance and metastasis by inducing autophagy in vitro and in vivo, and it may be a potential target for therapeutic intervention in HCC.

Primary Cilia Blockage Promotes the Malignant Behaviors of Hepatocellular Carcinoma via Induction of Autophagy.

Primary cilia are organelles protruding from cell surface into environment that function in regulating cell cycle and modulating cilia-related signal. Primary ciliogenesis and autophagy play important roles in tumorigenesis. However, the functions and interactions between primary cilia and autophagy in hepatocellular carcinoma (HCC) have not been reported yet. Here, we aimed to investigate the relationship and function of primary cilia and autophagy in HCC. In vitro, we showed that serum starvation stimuli could trigger primary ciliogenesis in HCC cells. Blockage of primary ciliogenesis by IFT88 silencing enhanced the proliferation, migration, and invasion ability of HCC cells. In addition, inhibition of primary cilia could positively regulate autophagy. However, the proliferation, migration, and invasion ability which were promoted by IFT88 silencing could be partly reversed by inhibition of autophagy. In vivo, interference of primary cilia led to acceleration of tumor growth and increase of autophagic flux in xenograft HCC mouse models. Moreover, IFT88 high expression or ATG7 low expression in HCC tissues was correlated with longer survival time indicated by the Cancer Genome Atlas (TCGA) analysis. In conclusion, our study demonstrated that blockage of primary ciliogenesis by IFT88 silencing had protumor effects through induction of autophagy in HCC. These findings define a newly recognized role of primary cilia and autophagy in HCC.

Chinese Trauma Surgeon Association for management guidelines of vacuum sealing drainage application in abdominal surgeries-Update and systematic review.

Vacuum sealing drainage (VSD) is frequently used in abdominal surgeries. However, relevant guidelines are rare. Chinese Trauma Surgeon Association organized a committee composed of 28 experts across China in July 2017, aiming to provide an evidence-based recommendation for the application of VSD in abdominal surgeries. Eleven questions regarding the use of VSD in abdominal surgeries were addressed: (1) which type of materials should be respectively chosen for the intraperitoneal cavity, retroperitoneal cavity and superficial incisions? (2) Can VSD be preventively used for a high-risk abdominal incision with primary suture? (3) Can VSD be used in severely contaminated/infected abdominal surgical sites? (4) Can VSD be used for temporary abdominal cavity closure under some special conditions such as severe abdominal trauma, infection, liver transplantation and intra-abdominal volume increment in abdominal compartment syndrome? (5) Can VSD be used in abdominal organ inflammation, injury, or postoperative drainage? (6) Can VSD be used in the treatment of intestinal fistula and pancreatic fistula? (7) Can VSD be used in the treatment of intra-abdominal and extra-peritoneal abscess? (8) Can VSD be used in the treatment of abdominal wall wounds, wound cavity, and defects? (9) Does VSD increase the risk of bleeding? (10) Does VSD increase the risk of intestinal wall injury? (11) Does VSD increase the risk of peritoneal adhesion? Focusing on these questions, evidence-based recommendations were given accordingly. VSD was strongly recommended regarding the questions 2-4. Weak recommendations were made regarding questions 1 and 5-11. Proper use of VSD in abdominal surgeries can lower the risk of infection in abdominal incisions with primary suture, treat severely contaminated/infected surgical sites and facilitate temporary abdominal cavity closure.

IL-37 suppresses the sustained hepatic IFN-γ/TNF-α production and T cell-dependent liver injury.

T cell-dependent liver injury is an important reason for the massive hepatic damage and cirrhosis. So far it is unclear whether the development of the disease could be efficiently suppressed by anti-inflammatory cytokine that modulates innate immune cells. Here we report that anti-inflammatory cytokine IL-37 could efficiently suppress the sustained hepatic expression of IFN-γ and TNF-α, two critical cytokines for inducing hepatocyte apoptosis and liver fibrosis in T cell-dependent liver injury. IL-37 could directly suppress IFN-γ/TLR4 ligand-induced M1 activation of macrophages, thus reducing the expression of pro-inflammatory cytokines TNF-α, IL-1ß, and IL-12. Moreover, IL-37 attenuated Th1 response in vivo and increased the expression of Th2 cytokines IL-4 and IL-13, which in turn promoted M2 activation of macrophages in the liver. The increase of M2 activation not only further reduced TNF-α, IL-1ß and IL-12 expression, but also increased IL-10 and IL-1Ra expression in macrophages, thus more efficiently suppressing the hepatic IFN-γ expression. By suppressing IFN-γ/TNF-α expression, IL-37 suppressed the up-regulation and activation of MLKL that drives hepatocellular necrosis in T cell-dependent liver damage. Accordingly, IL-37 efficiently reduced liver injury and hepatic inflammation after the repeated ConA challenge and the induction of autoimmune hepatitis, and also suppressed hepatic fibrosis resulting from the sustained liver damage. This study showed that the direct and indirect effect of IL-37 on macrophages could reduce the hepatic TNF-α expression, and also modulate IL-1ß/IL-12 and IL-10/IL-1Ra expression to suppress the hepatic IFN-γ expression, thus suppressing the development of T cell-dependent liver injury such as autoimmune hepatitis.

Circular RNAs in digestive system cancer: potential biomarkers and therapeutic targets.

Circular RNAs (circRNAs) are a series of special closed circular RNA molecules with stability and conservatism. In recent years, advances in high-throughput RNA sequencing technology have led to explosive discovery of circRNAs in different types of species and cells. Moreover, circRNAs can accomplish a remarkable multitude of biological functions, such as regulating transcription or splicing, serving as miRNA sponges, interacting with RNA-binding proteins, and translating proteins. Meanwhile, circRNAs involve in the biogenesis and development of many diseases, including cardiovascular disorders, nervous system disorders, cancers, etc. Herein, we discuss the latest research progress of circRNA, as well as their diagnostic and prognostic significance in digestive system cancers. In addition, this paper highlights that circRNAs might serve as potential therapeutic targets for novel drugs by taking digestive system cancer as an illustrative example.

The role of autophagy in hepatocellular carcinoma: friend or foe.

Autophagy is an evolutionarily conserved lysosome-dependent catabolic process which degrades cell's components in order to recycle substrates to exert optimally and adapt to tough circumstances. It is a critical cellular homeostatic mechanism with stress resistance, immunity, antiaging, and pro-tumor or anti-tumor effects. Among these, the role of autophagy in cancer is the most eye-catching that is not immutable but dynamic and highly complex. Basal autophagy acts as a tumor suppressor by maintaining genomic stability in normal cells. However, once a tumor is established, unbalanced autophagy will contribute to carcinoma cell survival under tumor microenvironment and in turn promote tumor growth and development. The dynamic role of autophagy can also apply on hepatocellular carcinoma (HCC). HCC is a highly malignant cancer with high morbidity and poor survival rate. Decline or overexpression of autophagic essential genes such as ATG7, ATG5 or Beclin 1 plays a key role in the occurrence and development of HCC but the exact mechanisms are still highly controversial. Signaling pathways or molecules involving in autophagy, for example PI3K/AKT/mTOR pathway, ERK/MAPK pathway, PERK pathway, p53, LncRNA PTENP1 (Long non-coding RNA PTENP1), microRNA-375 and so on, occupy an important position in the complex role of autophagy in HCC. Here, we discuss the dynamic role, the signaling pathways and the potential prognostic and therapy value of autophagy in HCC.

Traditional Chinese herbal extracts inducing autophagy as a novel approach in therapy of nonalcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver diseases around the world due to the modern sedentary and food-abundant lifestyle, which is characterized by excessive fat accumulation in the liver related with causes other than alcohol abuse. It is widely acknowledged that insulin resistance, dysfunctional lipid metabolism, endoplasmic reticulum stress, oxidative stress, inflammation, and apoptosis/necrosis may all contribute to NAFLD. Autophagy is a protective self-digestion of intracellular organelles, including lipid droplets (lipophagy), in response to stress to maintain homeostasis. Lipophagy is another pathway for lipid degradation besides lipolysis. It is reported that impaired autophagy also contributes to NAFLD. Some studies have suggested that the histological characteristics of NAFLD (steatosis, lobular inflammation, and peri-sinusoid fibrosis) might be improved by treatment with traditional Chinese herbal extracts, while autophagy may be induced. This review will provide insights into the characteristics of autophagy in NAFLD and the related role/mechanisms of autophagy induced by traditional Chinese herbal extracts such as resveratrol, Lycium barbarum polysaccharides, dioscin, bergamot polyphenol fraction, capsaicin, and garlic-derived S-allylmercaptocysteine, which may inhibit the progression of NAFLD. Regulation of autophagy/lipophagy with traditional Chinese herbal extracts may be a novel approach for treating NAFLD, and the molecular mechanisms should be elucidated further in the near future.

MiR-497 suppresses angiogenesis and metastasis of hepatocellular carcinoma by inhibiting VEGFA and AEG-1.

Hepatocellular carcinoma (HCC) is a worldwide malignance and displays marked vascular abnormalities and active metastasis. MicroRNAs (miRNAs) have been shown to play important roles in regulating tumor properties in cancer, however, whether miR-497 contributes to HCC angiogenesis or metastasis remains unclear. In this study, we found that miR-497 was significantly down-regulated in HCC tissue samples and cell lines. Gain-of-function and loss-of-function studies revealed that miR-497 could repress both the pro-angiogenic and metastatic ability of HCC cells. Subsequent investigations disclosed that miR-497 directly inhibited the 3'-untranslated regions (UTRs) of vascular endothelial growth factor A (VEGFA) and astrocyte elevated gene-1 (AEG-1). Furthermore, overexpression of these targets antagonized the function of miR-497. Based on nude mouse models, we demonstrated that overexpression of miR-497 significantly repressed microvessel densities in xenograft tumors and reduced pulmonary metastasis. In conclusion, our findings indicate that miR-497 downregulation contributes to angiogenesis and metastasis in HCC.

Mouse models of liver cancer: Progress and recommendations.

To clarify the pathogenesis of hepatocellular carcinoma (HCC) and investigate the effects of potential therapies, a number of mouse models have been developed. Subcutaneous xenograft models are widely used in the past decades. Yet, with the advent of in vivo imaging technology, investigators are more and more concerned with the orthotopic models nowadays. Genetically engineered mouse models (GEM) have greatly facilitated studies of gene function in HCC development. Recently, GEM of miR-122 and miR-221 provided new approaches for better understanding of the in vivo functions of microRNA in hepatocarcinogenesis. Chemically induced liver tumors in animals share many of the morphological, histogenic, and biochemical features of human HCC. Yet, the complicated and obscure genomic alternation restricts their applications. In this review, we highlight both the frequently used mouse models and some emerging ones with emphasis on their merits or defects, and give advises for investigators to chose a "best-fit" animal model in HCC research.

The emerging role of astrocyte-elevated gene-1 in hepatocellular carcinoma (Review).

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, yet effective treatment for this disease is lacking. Thus, there is an urgent need to identify novel therapeutic targets for this dreadful disease. Numerous studies have established that overexpression of astrocyte-elevated gene-1 (AEG-1) is frequently observed in multiple types of cancers including HCC, and its expression levels are correlated with the stage and grade of the disease. Further studies revealed that AEG-1 plays a key role in several crucial aspects of HCC progression, including growth, transformation, cell survival, invasion, metastasis and chemoresistance. Moreover, AEG-1 overexpression activates the Wnt/ß-catenin, mitogen-actived protein kinase (MAPK), nuclear factor (NF)-κB, and PI3K/Akt signaling pathways, and promotes its downstream gene expression to facilitate malignant potential. Recently, transgenic mice with hepatocyte-specific expression of AEG-1 (Alb/AEG-1) and AEG-1-knockout mouse both revealed novel aspects of the functions of AEG-1 in an in vivo context. This review evaluates the multi-functions of AEG-1 and describes the major signaling pathways and molecular alterations regulated by AEG-1 in HCC, indicating its key roles and potential as a biomarker or significant target for the therapy of HCC.

Sirtuin 6 promotes transforming growth factor-ß1/H2O2/HOCl-mediated enhancement of hepatocellular carcinoma cell tumorigenicity by suppressing cellular senescence.

Sirtuin 6 (SIRT6) can function as a tumor suppressor by suppressing aerobic glycolysis and apoptosis resistance. However, the negative effect of SIRT6 on cellular senescence implies that it may also have the potential to promote tumor development. Here we report that the upregulation of SIRT6 expression was required for transforming growth factor (TGF)-ß1 and H2O2/HOCl reactive oxygen species (ROS) to promote the tumorigenicity of hepatocellular carcinoma (HCC) cells. Transforming growth factor-ß1/H2O2/HOCl could upregulate SIRT6 expression in HCC cells by inducing the sustained activation of ERK and Smad pathways. Sirtuin 6 in turn abrogated the inducing effect of TGF-ß1/H2O2/HOCl on cellular senescence of HCC cells, and was required for the ERK pathway to efficiently suppress the expression of p16 and p21. Sirtuin 6 altered the effect of Smad and p38 MAPK pathways on cellular senescence, and contributed to the inhibitory effect of the ERK pathway on cellular senescence. However, SIRT6 was inefficient in antagonizing the promoting effect of TGF-ß1/H2O2 HOCl on aerobic glycolysis and anoikis resistance. Intriguingly, if SIRT6 expression was inhibited, the promoting effect of TGF-ß1/H2O2/HOCl on aerobic glycolysis and anoikis resistance was not sufficient to enhance the tumorigenicity of HCC cells. Suppressing the upregulation of SIRT6 enabled TGF-ß1/H2O2/HOCl to induce cellular senescence, thereby abrogating the enhancement of HCC cell tumorigenicity by TGF-ß1/H2O2/HOCl. These results suggest that SIRT6 is required for TGF-ß1/H2O2/HOCl to enhance the tumorigenicity of HCC cells, and that targeting the ERK pathway to suppress the upregulation of SIRT6 might be a potential approach in comprehensive strategies for the therapy of HCC.

ß3 integrin promotes TGF-ß1/H2O2/HOCl-mediated induction of metastatic phenotype of hepatocellular carcinoma cells by enhancing TGF-ß1 signaling.

In addition to being an important mediator of migration and invasion of tumor cells, ß3 integrin can also enhance TGF-ß1 signaling. However, it is not known whether ß3 might influence the induction of metastatic phenotype of tumor cells, especially non-metastatic tumor cells which express low level of ß3. Here we report that H2O2 and HOCl, the reactive oxygen species produced by neutrophils, could cooperate with TGF-ß1 to induce metastatic phenotype of non-metastatic hepatocellular carcinoma (HCC) cells. TGF-ß1/H2O2/HOCl, but not TGF-ß1 or H2O2/HOCl, induced ß3 expression by triggering the enhanced activation of p38 MAPK. Intriguingly, ß3 in turn promoted TGF-ß1/H2O2/HOCl-mediated induction of metastatic phenotype of HCC cells by enhancing TGF-ß1 signaling. ß3 promoted TGF-ß1/H2O2/HOCl-induced expression of itself via positive feed-back effect on p38 MAPK activation, and also promoted TGF-ß1/H2O2/HOCl-induced expression of α3 and SNAI2 by enhancing the activation of ERK pathway, thus resulting in higher invasive capacity of HCC cells. By enhancing MAPK activation, ß3 enabled TGF-ß1 to augment the promoting effect of H2O2/HOCl on anoikis-resistance of HCC cells. TGF-ß1/H2O2/HOCl-induced metastatic phenotype was sufficient for HCC cells to extravasate from circulation and form metastatic foci in an experimental metastasis model in nude mice. Inhibiting the function of ß3 could suppress or abrogate the promoting effects of TGF-ß1/H2O2/HOCl on invasive capacity, anoikis-resistance, and extravasation of HCC cells. These results suggest that ß3 could function as a modulator to promote TGF-ß1/H2O2/HOCl-mediated induction of metastatic phenotype of non-metastatic tumor cells, and that targeting ß3 might be a potential approach in preventing the induction of metastatic phenotype of non-metastatic tumor cells.

[Expression and clinical significance of nerve growth factor in primary liver cancer].

OBJECTIVE: To determine the expression of nerve growth factor (NGF) in hepatic tissues and serum of patients with primary liver cancer (PLC), and to investigate the relationship of serum NGF levels with clinicopathological features of PLC. METHODS: Hepatocellular carcinoma (HCC) samples and patient-matched tumor-adjacent liver samples were collected from 26 PLC patients to assess the mRNA and protein expressions of NGF by reverse transcription-PCR, western blotting (b-actin normalized), and immunohistochemistry. In addition, serum samples were collected from 40 PLC patients, 40 liver cirrhosis patients, 40 chronic hepatitis patients (including hepatitis B or C virus infections), and 30 healthy (normal) controls. The serum levels of NGF were measured by enzyme-linked immunosorbent assay. Intergroup differences were assessed by the t-test, and correlation with sex, age, presence of cirrhosis, tumor size, and TNM classification were assessed by the Kruskal-Wallis H test followed the Mann-Whitney U test. RESULTS: HCC tissues showed higher mRNA and protein expressions of NGF than the corresponding tumor-adjacent non-HCC tissues. Hepatic NGF expression was mainly localized to the tumor cell cytoplasm. Serum NGF expression was significantly higher in PLC patients (33.86+/-16.11 pg/ml) and cirrhosis patients (20.57+/-9.73 pg/ml) than in normal controls (11.13+/-6.12 pg/ml) and chronic hepatitis patients (13.20+/-6.23 pg/ml) (P less than 0.01). Furthermore, when the PLC patients were stratified according to tumor size and TNM stage, the serum NGF level was found to be significantly higher in patients with tumors more than 5 cm (vs. less than 5 cm; U=83.000, P=0.002) or of TNM stage III/IV (vs. stage I/II; U=103.500, P=0.009). CONCLUSION: Elevated expression of NGF in liver cancer tissues and serum of PLC patients is related with tumor size and TNM staging. These findings suggest that NGF may play a role in HCC tumorigenesis and/or that serum NGF may represent a prognostic marker of PLC.