Oncogenic signal transduction and therapeutic strategy for hepatocellular carcinoma

Puerarin inhibits hepatocellular carcinoma invasion and metastasis through miR-21-mediated PTEN/AKT signaling to suppress the epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) is one of the most common primary malignant tumors of the liver worldwide. Liver resection and transplantation are currently the only effective treatments; however, recurrence and metastasis rates are still high. Previous studies have shown that the epithelial-mesenchymal transition (EMT) is a key step in HCC invasion and metastasis. Inhibition of EMT has become a new therapeutic strategy for tumors. Recently, puerarin, a well-characterized component of traditional Chinese medicine, has been isolated from Pueraria radix and exerts positive effects on many diseases, particularly cancers. In this study, CCK-8, EdU immunofluorescence, colony formation, wound healing, and migration assays were used to detect the effects of puerarin on HCC cells. We further analyzed the relationship between puerarin and miR-21/PTEN/EMT markers in HCC cell lines. Our results showed that HCC cell proliferation, migration, invasion, tumor formation, and metastasis were reduced by puerarin in vitro and in vivo. Additionally, puerarin inhibited the EMT process of HCC by affecting the expression of Slug and Snail. Moreover, oncogenic miR-21 was inhibited by puerarin, coupled with an increase in the tumor suppressor gene PTEN. Increasing miR-21 expression or decreasing PTEN expression reversed the inhibition effects of puerarin in HCC. These data confirmed that puerarin affects HCC through the miR-21/PTEN/EMT regulatory axis. Overall, puerarin may represent a chemopreventive and/or chemotherapeutic agent for HCC treatment.

AP-2β inhibits hepatocellular carcinoma invasion and metastasis through Slug and Snail to suppress epithelial-mesenchymal transition

Transcription factor AP-2β plays an important role in human cancer, but its clinical significance in hepatocellular carcinogenesis is largely unknown.

Methods: AP-2β expression was detected in human hepatocellular cancer (HCC) tissues and cell lines. The effects of AP-2β on HCC proliferation, migration, invasion, tumor formation and metastasis were evaluated by MTT, colony formation and transwell assays in vitro and mouse experiments in vivo. The association between AP-2β and miR-27a/EMT markers in HCC cell lines and tissues was analyzed.

Results: AP-2β expression was decreased in HCC tissues and cell lines. Reduced expression of AP-2β was significantly associated with more advanced tumor stages and larger tumor sizes. The overexpression of AP-2β reduced HCC proliferation, migration, invasion, tumor formation and metastasis in vitro and in vivo. Additionally, AP-2β overexpression increased the sensitivity of HCC cells to cisplatin. Moreover, AP-2β modulates the levels of EMT markers through Slug and Snail in HCC cell lines and tissues. Furthermore, oncogenic miR-27a inhibits AP-2β expression by binding to the AP-2β 3′ untranslated region (UTR) and reverses the tumor suppressive role of AP-2β.

Conclusion: These results suggested that AP-2β is lowly expressed in HCC by inhibiting EMT signaling to regulate HCC cell growth and migration. Therefore, AP-2β in the novel miR-27a/AP-2β/Slug/EMT regulatory axis enhances the chemotherapeutic drug sensitivity of HCC and might represent a potential target for evaluating the treatment and prognosis of human HCC.

Precision medicine based on surgical oncology in the era of genome-scale analysis and genome editing technology

Accumulated evidence suggests that multiple molecular and cellular interactions promote cancer evolution in vivo. Surgical oncology is of growing significance to a comprehensive understanding of the malignant diseases for therapeutic application. We have analyzed more than 1000 clinical samples from surgically resected tissue to identify molecular biomarkers and therapeutic targets for advanced malignancies. Cancer stemness and mitotic instability were then determined as the essential predictors of aggressive phenotype with poor prognosis. Recently, whole genome/exome sequencing showed a mutational landscape underlying phenotype heterogeneity in caners. In addition, integrated genomic, epigenomic, transcriptomic, metabolic, proteomic and phenomic analyses elucidated several molecular subtypes that cluster in liver, pancreatic, biliary, esophageal and gastroenterological cancers. Identification of each molecular subtype is expected to realize the precise medicine targeting subtype‐specific molecules; however, there are obstacle limitations to determine matching druggable targets or synthetic lethal interactions. Current breakthroughs in genome editing technology can provide us with unprecedented opportunity to recapitulate subtype‐specific pathophysiology in vitro and in vivo. Given a great potential, on‐demand editing system can design actionable strategy and revolutionize precision cancer medicine based on surgical oncology.

Glycogen synthase kinase-3β is associated with the prognosis of hepatocellular carcinoma and may mediate the influence of type 2 diabetes mellitus on hepatocellular carcinoma

BACKGROUND

Although many studies have shown glycogen synthase kinase-3β (GSK-3β) was associated with type 2 diabetes mellitus (T2DM) and implicated with a wide range of cancers, the role of GSK-3β in hepatocellular carcinoma(HCC) and the correlation among GSK-3β, T2DM and HCC remains unclear. Our objectives were to identify the effect of p-Ser9-GSK-3β on the prognosis of patients with HCC and to learn more about the interaction among T2DM, GSK-3β and the prognosis of HCC.

METHODS

Firstly we used reverse transcriptase-PCR(RT-PCR) and western blotting to determine the expression levels of GSK-3β and p-Ser9-GSK-3β in human HCC samples. We then used immunohistochemical staining to evaluate the expression pattern of p-Ser9-GSK-3β in 178 patients with HCC after curative partial hepatectomy. Finally we statistically analyzed the association of p-Ser9-GSK-3β and T2DM with the prognosis of patients with HCC.

RESULTS

P-Ser9-GSK-3β was over-expressed in tumor tissues compared with their normal counterparts. Correlation and regression analysis indicated that the over-expression of p-Ser9-GSK-3β was significantly associated with T2DM, and the correlation coefficient was 0.259 (P = 0.001). Multivariate analysis showed that the over-expression of p-Ser9-GSK-3β(P<0.001) and T2DM(P = 0.008) were independently associated with poor prognosis of HCC, respectively. Further analysis demonstrated that these two variables are closely related with each other.

CONCLUSION

The over-expression of p-Ser9-GSK-3β and T2DM are strongly correlated with worse surgical outcome of HCC. P-Ser9-GSK-3β may play a significant role in mediating the influence of T2DM on the prognosis of HCC.

Molecular targeted therapies in hepatocellular carcinoma

In vivo tumor progression requires the supply of oxygen and nutrition by neovasculature. Hepatocellular carcinoma (HCC) is one of the typical tumors with neovascularization, and the dramatic alteration in the arterial vascularity may lead to acquisition of the potential for vascular invasiveness and metastasis. In 2008, phase III clinical trials revealed anti-angiogenic agent "sorafenib" as the first drug that demonstrated an improved overall survival in patients with advanced HCC. A new era of HCC treatment had arrived, but there has been limited further improvement in survival benefits. This review summarizes molecular targeted therapy with a focus on angiogenesis, growth signals, and mitotic abnormalities, as well as the promising concepts of "cancer stemness" and "synthetic lethality" for the strategy of targeted therapy.

Epidermal growth factor induces tumour marker AKR1B10 expression through activator protein-1 signalling in hepatocellular carcinoma cells

AKR1B10 (aldo-keto reductase 1B10) is overexpressed in liver and lung cancer, and plays a critical role in tumour development and progression through promoting lipogenesis and eliminating cytotoxic carbonyls. AKR1B10 is a secretory protein and potential tumour marker; however, little is known about the regulatory mechanism of AKR1B10 expression. The present study showed that AKR1B10 is induced by mitogen EGF (epidermal growth factor) and insulin through the AP-1 (activator protein-1) signalling pathway. In human HCC (hepatocellular carcinoma) cells (HepG2 and Hep3B), EGF (50 ng/ml) and insulin (10 nM) stimulated endogenous AKR1B10 expression and promoter activity. In the AKR1B10 promoter, a putative AP-1 element was found at bp -222 to -212. Deletion or mutation of this AP-1 element abrogated the basal promoter activity and response to EGF and AP-1 proteins. This AP-1 element bound to nuclear proteins extracted from HepG2 cells, and this binding was stimulated by EGF and insulin in a dose-dependent manner. Chromatin immunoprecipitation showed that the AP-1 proteins c-Fos and c-Jun were the predominant factors bound to the AP-1 consensus sequence, followed by JunD and then JunB. The same order was followed in the stimulation of endogenous AKR1B10 expression by AP-1 proteins. Furthermore, c-Fos shRNA (short hairpin RNA) and AP-1 inhibitors/antagonists (U0126 and Tanshinone IIA) inhibited endogenous AKR1B10 expression and promoter activity in HepG2 cells cultured in vitro or inoculated subcutaneously in nude mice. U0126 also inhibited AKR1B10 expression induced by EGF. Taken together, these results suggest that AKR1B10 is up-regulated by EGF and insulin through AP-1 mitogenic signalling and may be implicated in hepatocarcinogenesis.

Molecular targeted therapy for hepatocellular carcinoma in the current and potential next strategies

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its incidence is still increasing. While the primary curative treatment for HCC is surgical resection, a major obstacle for the treatment of HCC is the high frequency of tumor recurrence even after curative resection. Effective palliative treatment is hindered by the evidence that HCC is frequently resistant to conventional chemotherapy and radiotherapy. Targeted therapy which specifically inhibits molecular abnormalities has emerged as a novel approach for the innovative and effective medical treatment of malignancies. In order to fulfill this promise there is an urgent need to identify the optimal targets for the treatment of HCC. A multi-kinase angiogenesis inhibitor, sorafenib, has been revealed as the first agent to show favorable overall survival in patients with advanced HCC. A new era of HCC treatment has arrived, but there has been limited improvement in survival benefits with the status quo. This review summarizes molecular targeted therapy for HCC, with a focus on angiogenesis, growth signaling, and mitosis, as well as a promising concept, "cancer stemness" for the current and potential next strategies of HCC treatment.

Molecular targeted therapy for hepatocellular carcinoma in the current and potential next strategies

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its incidence is still increasing. While the primary curative treatment for HCC is surgical resection, a major obstacle for the treatment of HCC is the high frequency of tumor recurrence even after curative resection. Effective palliative treatment is hindered by the evidence that HCC is frequently resistant to conventional chemotherapy and radiotherapy. Targeted therapy which specifically inhibits molecular abnormalities has emerged as a novel approach for the innovative and effective medical treatment of malignancies. In order to fulfill this promise there is an urgent need to identify the optimal targets for the treatment of HCC. A multi-kinase angiogenesis inhibitor, sorafenib, has been revealed as the first agent to show favorable overall survival in patients with advanced HCC. A new era of HCC treatment has arrived, but there has been limited improvement in survival benefits with the status quo. This review summarizes molecular targeted therapy for HCC, with a focus on angiogenesis, growth signaling, and mitosis, as well as a promising concept, "cancer stemness" for the current and potential next strategies of HCC treatment.

Preparation and characterization of zedoary turmeric oil-loaded insulin-modified sterically stabilized liposomes

The poor selectivity of anticancer drugs often leads to their multiplicate dose-limiting toxicities in humans, which severely restricts their clinical application. In this study, a novel liposomal formulation of zedoary turmeric oil (ZTO) targeting the insulin receptor (IR) was prepared by covalently conjugating insulin to the terminal of the polyethylene glycol (PEG) chain of sterically stabilized liposomes. In vitro assays indicated that a higher uptake of insulin-modified sterically stabilized liposomes (ISSLs) was observed in SMMC-7721 hepatocarcinoma cells overexpressing insulin receptors. IC(50) values of ISSLs, NTLs (nontargeted liposomes), and ZTO injection (free ZTO) against SMMC-7721, determined by MTT assays, were 157.2, 256.7, and 43.3 microg x ml(-1), respectively. Plasma-clearance profiles of ZTO in the liposomal formulations were then compared with that of ZTO injection. The liposomal formulations showed much longer terminal half-lives (11.24 and 14.73 hours for ISSLs and NTLs, respectively) than that of ZTO injection (1.45 hours). All results above indicated the ISSLs were potentially useful for the treatment of IR (+) tumors and are worthy of further investigation.

The selective Aurora B kinase inhibitor AZD1152 as a novel treatment for hepatocellular carcinoma

BACKGROUND & AIMS

We previously identified that high Aurora B expression was associated with hepatocellular carcinoma (HCC) recurrence due to tumor dissemination. In this preclinical study, a novel inhibitor of Aurora B kinase was evaluated as a treatment for human HCC.

METHODS

AZD1152 is a selective inhibitor of Aurora B kinase. Twelve human HCC cell lines were analyzed for Aurora B kinase expression and the in vitro effects of AZD1152. The in vivo effects of AZD1152 were analyzed in a subcutaneous xenograft model and a novel orthotopic liver xenograft model.

RESULTS

Aurora B kinase expression varied among the human HCC cell lines and was found to correlate with inhibition of cell proliferation, accumulation of 4N DNA, and the proportion of polyploid cells following administration of AZD1152-hydroxyquinazoline-pyrazol-anilide (AZD1152-HQPA). AZD1152-HQPA suppressed histone H3 phosphorylation and induced cell death in a dose-dependent manner. Growth of subcutaneous human HCC xenografts was inhibited by AZD1152 administration. In an orthotopic hepatoma model, treatment with AZD1152 significantly decelerated tumor growth and increased survival. Pharmacobiological analysis revealed that AZD1152 induced the rapid suppression of phosphohistone H3, followed by cellular apoptosis in the liver tumors but not in the normal tissues of the orthotopic models.

CONCLUSIONS

Our preclinical studies indicate that AZD1152 is a promising novel therapeutic approach for the treatment of HCC.

Surgical contribution to recurrence-free survival in patients with macrovascular-invasion-negative hepatocellular carcinoma

BACKGROUND

Macroscopic vascular invasion (MVI) is a well-known indicator of recurrence of hepatocellular carcinoma (HCC) even after curative hepatectomy, but the clinicopathologic and molecular features of the recurrence remain unclear in MVI-negative HCC.

STUDY DESIGN

Two hundred seven consecutive patients with confirmed primary MVI-negative HCC were retrospectively assessed after curative resection, with special emphasis on the importance of anatomically systematized hepatectomy. HCC tissues were also analyzed for genome-wide gene expression profile of each tumor using a microarray technique.

RESULTS

Univariant analysis of HCC recurrence revealed multiple tumors (p < 0.001), moderate to poor differentiation (p = 0.044), Child-Pugh B/C (p = 0.047), alpha-fetoprotein elevation (p = 0.007), and nonanatomic hepatectomy (p = 0.010) as risk factors. According to Cox hazard multivariant analysis, multiple tumors (p = 0.002), alpha-fetoprotein elevation (p < 0.001), and nonanatomic hepatectomy (p = 0.002) were identified as independent factors of the recurrence. In the recurrent cases after anatomic hepatectomy for HCC, local recurrence was significantly infrequent compared with those after nonanatomic hepatectomy (p < 0.001). Network expression analysis using cDNA microarray revealed distinct signaling pathways of epithelial-mesenchymal transitions are associated with recurrence after anatomically systematized hepatectomy.

CONCLUSIONS

Anatomically systematized hepatectomy might contribute to recurrence-free survival of HCC patients of HCC without MVI. Local recurrence could be mostly averted by anatomic hepatectomy, although specific epithelial-mesenchymal transitions signaling might regulate the biologic aggressiveness of HCC.

Molecularly targeted therapy for hepatocellular carcinoma

Accumulated understanding of the molecular pathways regulating cancer progression has led to the development of novel targeted therapies. Hepatocellular carcinoma (HCC) remains a highly lethal disease that is resistant to conventional cytotoxic chemotherapy and radiotherapy. Unlike conventional chemotherapy, molecular-targeted agents offer the potential advantages of a relatively high therapeutic window and use in combination with other anticancer strategies without overlapping toxicity. It is hoped that these drugs will become valuable therapeutic tools within the multimodal approach to treating cancer. A recent clinical trial revealed an oral multikinase inhibitor, sorafenib, as the first agent that has demonstrated improved overall survival in patients with advanced HCC. The present review summarizes molecular abnormalities of HCC with a focus on clinical studies, and current status as well as problems of the targeted strategies for HCC.

Overexpression of insulin receptor substrate-2 in human and murine hepatocellular carcinoma

De-regulations in insulin and insulin-like growth factor (IGF) pathways may contribute to hepatocellular carcinoma. Although intracellular insulin receptor substrate-2 (IRS-2) is the main effector of insulin signaling in the liver, its role in hepatocarcinogenesis is unknown. Here, we show that IRS-2 was overexpressed in two murine models of hepatocarcinogenesis: administration of diethylnitrosamine and hepatic overexpression of SV40 large T antigen. In both models, IRS-2 overexpression was detected in preneoplastic lesions and at higher levels in tumoral nodules. IRS-2 overexpression associated with IGF-2 and IRS-1 overexpression and with GSK-3beta inhibition. Increased expression of IRS-2 was also detected in human hepatocellular carcinoma specimens and hepatoma cell lines. In murine and human hepatoma cells, IRS-2 protein induction associated with increased IRS-2 mRNA levels. The functionality of IRS-2 was demonstrated in Hep 3 B cells, in which IRS-2 tyrosine phosphorylation and its association with phosphatidylinositol-3 kinase were induced by IGF-2. Moreover, down-regulation of IRS-2 expression increased apoptosis in these cells. In conclusion, we demonstrate that IRS-2 is overexpressed in human and murine hepatocellular carcinoma. The emergence of IRS-2 overexpression at preneoplastic stages during experimental hepatocarcinogenesis and its protective effect against apoptosis suggest that IRS-2 contributes to liver tumor progression.

Synthesis and characterization of the tumor targeting mitoxantrone-insulin conjugate

Anticancer drugs have serious side effects arising from their poor malignant cells selectivity. Since insulin receptors highly express on the cytomembrane of some kind of tumor cells, using insulin as the vector was expected to reduce serious side effects of the drugs. The objective of this study was to evaluate the tumor targeting effect of the newly synthesized mitoxantrone-insulin conjugate (MIT-INS) with the drug loading of 11.68%. In vitro stability trials showed MIT-INS were stable in buffers with different pH (2-8) at 37 degrees C within 120 h (less than 3% of free MIT released), and were also stable in mouse plasma within 48 h (less than 1% of free MIT released). In vivo study on tumor-bearing mice showed that, compared with MIT [75.92 microg x h/g of the area under the concentration-time curve (AUC) and 86.85 h of mean residence time (MRT)], the conjugates had better tumor-targeting efficiency with enhanced tumor AUC of 126.53 microg x h/g and MTR of 151.95 h. The conjugate had much lower toxicity to most other tissues with targeting indexes (TIC) no larger than 0.3 besides good tumor targeting efficiency with TIC of 1.67. The results suggest the feasibility to promote the curative effect in cancer chemotherapy by using insulin as the vector of anti-cancer drugs.