The PGC1α/NRF1-MPC1 axis suppresses tumor progression and enhances the sensitivity to sorafenib/doxorubicin treatment in hepatocellular carcinoma.

Targeting energy metabolism holds the potential to effectively treat a variety of malignant diseases, and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) is a key regulator of energy metabolism. However, PGC1α's role in cancer, especially in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we reported that PGC1α was significantly downregulated in HCC cell lines and specimens. Moreover, reduced expression of PGC1α in tumor cells was correlated with poor prognosis. PGC1α overexpression substantially inhibited cell proliferation and induced apoptosis in vitro and in vivo. On the contrary, the knockdown of PGC1α produced the opposite effect. The mechanism was at least partially due to the upregulation of mitochondrial pyruvate carrier 1 (MPC1) caused by PGC1α, which promoted mitochondrial biogenesis by binding to nuclear respiratory factor 1 (NRF1). Consequently, the production of cellular reactive oxygen species (ROS) caused by mitochondrial oxidation was elevated above a critical threshold for survival. Furthermore, we found that PGC1α could enhance the antitumor activity of sorafenib and doxorubicin in HCC through ROS accumulation-mediated cell death. These results indicate that PGC1α/NRF1-MPC1 axis is involved in HCC progression and could be a promising target for HCC treatment.

8-methoxysmyrindiol from Gerbera piloselloides (L.) Cass. and its vasodilation effects on isolated rat mesenteric arteries.

Gerbera piloselloides (L.) Cass. (Compositae) possesses various biological effects. It is used as an oriental remedy for relieving cough and resolving phlegm. The present study is to investigate the vasodilation effects of Gerbera piloselloides on isolated rat mesenteric arteries (MAs) and the potential mechanism. Different organic extracts of Gerbera piloselloides were tested, and an HPLC-UV-FD-based analytical method was established to identify the active constituents. The principal components, namely, 8-MOP (8-methoxypsoralan) and 8-MSD (8-methoxysmyrindiol), were found to be predominant in the extracts of petroleum ether and dichloroform, which showed stronger vasodilation activities. 8-MSD was isolated from Gerbera piloselloides by silica gel column chromatography coupled with a Waters 2545 high throughput autopurification system, and its vasodilation effects were explored by an assay of tension on rat MA rings. The results suggest that 8-MSD induces vascular relaxation in rat MAs via an endothelium-dependent mechanism involving the Kir channel, which enables Ca2+ entry in the cell and activates production of NO. The present research indicates that 8-MSD may be therapeutically useful as an anti-hypertension agent and to potentially treat cardiovascular and gastrointestinal diseases.

Sodium orthovanadate overcomes sorafenib resistance of hepatocellular carcinoma cells by inhibiting Na+/K+-ATPase activity and hypoxia-inducible pathways.

The resistance to sorafenib highly affects its clinical benefits for treating hepatocellular carcinoma (HCC). Sodium orthovanadate (SOV) is a phosphate analog that displays anti-cancer activities against various types of malignancies including HCC. The present study has demonstrated that SOV is able to overcome sorafenib resistance and strengthens sorafenib in suppressing sorafenib-resistant HCC cells in vitro and in animal models. Similar to its action on parental HCC cells, SOV induced cell cycle arrest at G2/M phases by regulating cyclin B1 and cyclin-dependent kinase 1, and apoptosis by reducing mitochondrial membrane potential, in sorafenib-resistant HCC cells. More importantly, SOV inhibited ATPase activity, which was significantly elevated in sorafenib-resistant HCC cells. SOV also reduced the expression of HIF-1α and HIF-2α and their nuclear translocation, resulting in downregulation of their downstream factors including vascular endothelial growth factor, lactate dehydrogenase-A and glucose transporter 1. Its ability to inhibit ATPase activity and hypoxia-inducible pathways enabled SOV to efficiently suppress both normoxic and hypoxic cells, which compose cancer cell populations inside sorafenib-resistant HCC tumors. The present results indicate that SOV may be a potent candidate drug for overcoming the resistance to sorafenib in treating HCC.

Dual inhibition of Akt and c-Met as a second-line therapy following acquired resistance to sorafenib in hepatocellular carcinoma cells.

Sorafenib displays a limited efficacy for advanced hepatocellular carcinoma (HCC). Some patients with HCC initially respond to sorafenib, but eventually succumb to the disease, indicating that the acquired resistance to sorafenib reduces its beneficial effects. No alternative drugs are available after the failure of sorafenib therapy. Therefore, investigation of the mechanisms underlying the acquired resistance and development of second-line treatments for sorafenib-resistant HCC are urgently required. In this study, sorafenib-resistant HCC cells generated from sorafenib-sensitive human HCC cells were shown to overproduce hepatocyte growth factor (HGF) and overexpress c-Met kinase and its phosphorylated form, leading to the activation of Akt and ERK (extracellular signaling-regulated kinase) pathways. Use of specific c-Met inhibitors enhanced the effects of sorafenib by inhibiting the growth of sorafenib-resistant HCC cells. Akt inhibitors, a class of second-line therapeutic drugs under investigation for treating HCC in clinical trials, enhanced the effects of sorafenib, but also activated the c-Met pathway in sorafenib-resistant cells. Dual inhibition of Akt and c-Met by their respective inhibitors, MK2206 and capmatinib, additively or synergistically suppressed sorafenib-resistant HCC cells in vitro and sorafenib-resistant HCC xenografts in mice. The anticancer activities of MK2206 mainly rely on its ability to induce cell apoptosis and autophagic death, while capmatinib treatment leads to cell cycle arrest at phase G1. These results provide strong evidence for further investigation on the clinical utility of dual inhibition of Akt and c-Met, particularly MK2206 and capmatinib, as a second-line therapy for advanced HCC that has acquired resistance to sorafenib.

An artificial lncRNA targeting multiple miRNAs overcomes sorafenib resistance in hepatocellular carcinoma cells.

Sorafenib resistance remains a major obstacle for the effective treatment of hepatocellular carcinoma (HCC), and a number of miRNAs contribute to this resistance. However, the regulatory networks of miRNAs are very complex, thus inhibiting a single miRNA may sequentially activate other compensatory pathways. In the present study, we generated an artificial long non-coding RNA (AlncRNA), which simultaneously targets multiple miRNAs including miR-21, miR-153, miR-216a, miR-217, miR-494 and miR-10a-5p. These miRNAs have been shown to be upregulated in sorafenib-resistant cells and participate in the mechanisms underlying sorafenib resistance. The AlncRNA contains tandem sequences of 6 copies of the complementary binding sequences to the target miRNAs and is expressed by an adenoviral vector (Ad5-AlncRNA). Infection of Ad5-AlncRNA into sorafenib-resistant HCC cells blocked the function of miRNAs, and sequentially inhibited the downregulation of PTEN and activation of AKT. Ad5-AlncRNA significantly inhibited proliferation and induced apoptosis of sorafenib-resistant cells and enhanced the effects of sorafenib in vitro and in animal models. Inhibition of autophagy decreased the sensitivity of sorafenib-resistant cells to Ad5-AlncRNA, while its induction had the opposite effect. These results indicate that targeting multiple miRNAs by the artificial lncRNA could be a potential promising strategy for overcoming sorafenib resistance in the treatment of HCC.

Hydroxytyrosol, a natural molecule from olive oil, suppresses the growth of human hepatocellular carcinoma cells via inactivating AKT and nuclear factor-kappa B pathways.

The present study aimed to investigate the anti-cancer effects of hydroxytyrosol (HT) in human hepatocellular carcinoma (HCC) cells. Our results show that HT could inhibit proliferation, induce G2/M cell cycle arrest and apoptosis in human HCC cells. Mechanically, we found that HT could suppress the activation of AKT and nuclear factor-kappa B (NF-κB) pathways. HT also significantly inhibited the tumor growth, angiogenesis and the activation of AKT and NF-κB pathways in an orthotopic model of human HCC in vivo. These data suggest that HT may be a promising candidate agent for the treatment of HCC.

Hypoxia-mediated sorafenib resistance can be overcome by EF24 through Von Hippel-Lindau tumor suppressor-dependent HIF-1α inhibition in hepatocellular carcinoma.

UNLABELLED: 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.

Therapeutic effects of matrine on primary and metastatic breast cancer.

Matrine, one of the main components extracted from a traditional Chinese herb, Sophora flavescens Ait, has displayed anti-cancer activity in several types of cancer cells. This study aims to evaluate the therapeutic benefits of matrine on primary and metastatic breast cancer. Matrine inhibited the viability of and induced apoptosis in human MCF-7 and mouse 4T1 breast cancer cells in a dose-dependent manner in vitro as shown by MTT assay, flow cytometry and laser scanning confocal microscopy. Administration of matrine inhibited the growth of primary tumors and their metastases to lungs and livers, in a dose-dependent manner, in a highly metastatic model of 4T1 breast cancer established in syngeneic Balb/c mice. Tumors from matrine-treated mice had a smaller proliferation index, shown by immunostaining with an anti-Ki-67 antibody, a greater apoptosis index, shown by TUNEL-staining, and a less microvessel density, shown by immunostaining with an anti-CD31 A antibody, compared to the controls. Western blot analysis of tumoral homogenates indicated that matrine therapy reduced the ratio of Bcl-2/Bax, downregulated the expressions of VEGF and VEGFR-2, and increased the activation of caspase-3 and caspase-9. This study suggests matrine may be a potent agent, from a natural resource, for treating metastatic breast cancer because of its anti-apoptotic, anti-proliferative and anti-angiogenic activities.

Protective effects of emodin combined with danshensu on experimental severe acute pancreatitis.

OBJECTIVE AND DESIGN: In the present experiment, we aimed to determine the feasibility and curative effects of emodin combined with danshensu on experimental severe acute pancreatitis (SAP) and the mutual benefit of this synergistic strategy by a prospective animal study. MATERIAL: Eighty Wistar rats were randomly divided into four groups (n = 20). TREATMENT: SAP was elicited by a retrograde infusion of 5.0% sodium taurocholate into the pancreatic main duct. SAP rats in each group received no further intervention, emodin alone, danshensu (DSS) alone, and emodin combined with DSS (EDSS), respectively. METHODS: 48 h after SAP induction, all surviving animals were sacrificed to collect blood and tissue samples for the following measurements: serum levels of amylase, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), endotoxin and D-lactate. Pancreatic levels of TNF-alpha, IL-1beta, maleic dialdehyde (MDA), myeloperoxidase (MPO) activity, nuclear factor-kappaappaB (NF-kappaB) activation as well as wet-dry weight ratio were also evaluated. Ascitic fluid was quantified and the severity of pancreatic damage was analyzed by pathological grading and scoring. RESULTS: Compared with the SAP group, the emodin, DSS and EDSS groups had significant differences in every index. Furthermore, EDSS obviously improved all the parameters mentioned above so as to counteract inflammatory response and oxidative stress, as well as most effectively abating pancreatic and intestinal barrier injury. CONCLUSIONS: EDSS exerted protective effects on SAP rats and remarkably alleviated the severity of experimental SAP. Mechanisms that might account for the beneficial effects include protecting the intestinal barrier, inhibiting over-inflammatory reaction and abating oxidative stress. The combined strategy proved to be more effective than either emodin or DSS alone and may cause synergistic effects in combination in the early stage of SAP. Broad potential for future clinical practice is foreseeable.

Down-regulation of hypoxia-inducible factor-1alpha by hyperbaric oxygen attenuates the severity of acute pancreatitis in rats.

OBJECTIVES: This study investigated the role of hypoxia-inducible factor 1alpha (HIF-1alpha) in acute pancreatitis (AP) and whether HIF-1alpha is involved in the therapeutic effects of hyperbaric oxygen (HBO) on AP. METHODS: Thirty Wistar rats with taurocholate-induced AP were randomly assigned to 3 groups (each group had 10 rats) receiving oxygen, HBO, or no therapeutic treatment 4 hours after induction. Ten healthy sham-operated rats also served as controls. The arterial oxygen saturation, PaO2, pH, lactate dehydrogenase in the arterial sera, and amylase and tumor necrosis factor alpha in the venous sera were measured 6 hours after induction. Pancreatic tissues were subjected to histopathologic analysis, immunohistochemical and Western-blotted analyses of HIF-1alpha and vascular endothelial growth factor, and measuring of myeloperoxidase activity. RESULTS: The HBO therapy attenuated the severity of acute pancreatitis; reduced histopathologic scores, dry weight-wet weight ratio of pancreatic tissues, and levels of amylase and lactate dehydrogenase; and elevated blood arterial oxygen saturation, PaO2, and pH values. The HBO therapy inhibited AP-induced up-regulation of HIF-1alpha and its downstream effector vascular endothelial growth factor and the production of tumor necrosis factor alpha and myeloperoxidase activity. CONCLUSIONS: Hypoxia-inducible factor 1alpha plays a key role in the pathogenesis of AP, and the ability to down-regulate the expression of HIF-1alpha may partially explain the therapeutic effect of HBO on AP.

[The effect of hyperbaric oxygen on acute pancreatitis through downregulating hypoxia-inducible factor.].

OBJECTIVE: To observe the therapeutic effect of hyperbaric oxygen (HBO) on acute pancreatitis (AP) by downregulating hypoxia-inducible factor (HIF). METHODS: Forty Wistar rats were randomly divided into 4 groups (n = 10): sham group, AP group, normo-oxygen group (NP) and HBO group. At 4 hours after taurocholate-induced AP, the rats of NP group and HBO group were respectively treated with oxygen or HBO for 90 min. Several parameters were measured to evaluate oxygen stress after treatment including oxygen saturation (SaO2), partial pressure of oxygen (PO2), pH, and serum LDH. Pancreatic tissues were subjected to histopathological analysis, immunostained, and homogenized for Western blotted analysis of HIF-1alpha and VEGF, and measuring myeloperoxidase activity. The serum TNF-alpha and pancreatic histopathological scores were evaluated the severity of AP. RESULTS: It was proved by immunohistochemisty that HIF in acinar cell and polymorphonuclear leukocytes (PMNs) was activated and transferred from cytoplasm into nucleus in AP group, NP group, and HBO group, following upregulation of VEGF. HBO therapy elevated blood SaO2 (99.6% +/- 0.7% vs. 87.7% +/- 1.8% or 91.2% +/- 2.5%, P < 0.05) and PaO2 [(369.1 +/- 67.6) mm Hg (1 mm Hg = 0.133 kPa) vs. (86.6 +/- 5.6) mm Hg or (99.9 +/- 4.0) mm Hg, P < 0.05]. HBO therapy attenuated the severity of AP through inhibiting AP-induced upregulation of HIF-1alpha and VEGF, as evidenced by reducing histopathological scores (12.40 +/- 1.21 vs. 16.45 +/- 1.10 or 16.38 +/- 1.10, P < 0.05), dry/wet weight ratio of pancreatic tissues, and myeloperoxidase activity. CONCLUSIONS: HIF-1alpha plays a key role in the pathogenesis of AP. HBO therapy attenuates the severity of AP through downregulating the expression of HIF-1alpha.

[Protection of oxymatrine against ischemia-reperfusion injury of liver and mechanism thereof: experiment with rats].

OBJECTIVE: To investigate the effects of oxymatrine on protecting the liver against ischemia-reperfusion injury (IRI) and explore the mechanism thereof. METHODS: Thirty male Wistar rats were randomly divided into 3 equal groups: IRI group (2 ml normal saline was injected into the dorsal vein of penis, 30 min later laparotomy was performed, arterial clamp was used to grip the hepatic artery and portal vein for 30 minutes and then removed, the vessels were reperfused for 90 min, and 4 ml blood was collected from the aorta; parts of the liver were resected); oxymatrine group (oxymatrine 40 mg/kg was injected into the dorsal vein of penis, and the other procedures were the same as in the IRI group); and sham operation group (2 ml normal saline was injected into the dorsal vein of penis, laparotomy was performed, 150 min after the injection 4 ml blood was collected from the aorta and parts of the liver were resected). The levels of alanine transaminase (ALT) and aspartate transaminase (AST) were detected. The liver tissues underwent HE staining and TUNEL staining for pathological examination. Suspension of single hepatocytes was prepared to observe the ratio of apoptotic cells and cell cycles by flow cytometry (FCM). Western blotting was used to examine the Fas protein expression. RESULTS: The AST and ALT levels of the IRI group were 1326 U/L +/- 211 U/L and 768 U/L +/- 175 U/L respectively, significantly higher than those of the sham operation group (112 U/L +/- 53 U/L and 55 U/L +/- 17 U/L, both P < 0.05) and those of the oxymatrine group (513 U/L +/- 96 U/L and 352 U/L +/- 72 U/L respectively, both P < 0.01). The liver cells of the sham operation group were normal, those of the IRI group showed remarkable edema and cytoplasm degeneration. TUNEL staining showed remarkably more apoptotic cells in the IRI group. FCM showed that the apoptotic rate of hepatocytes was 42.8% +/- 5.2% in the IRI group, significantly higher than in the oxymatrine group (8.8% +/- 1.8%, P < 0.01), and that the ratio of hepatocytes in G(0)/G(1) stage of the IRI group was 99.2% +/- 1.8%, significantly higher than that of the sham operation group (77.0% +/- 2.1%), and that of the oxymatrine group (87.6% +/- 2.8%) (both P < 0.05); the ratio of hepatocytes in the S stage of the IRI group was 0.52% +/- 0.25%, significantly lower than those of the sham operation group (23.94% +/- 1.84%) and oxymatrine group (12.42% +/- 0.46%) (both P < 0.01). The Fas protein expression was significantly highly in the IRI group than in the oxymatrine group. CONCLUSION: Remarkably reducing the IRI of hepatocytes, oxymatrine has potential to protect the liver against IRI during surgical intervention.

Arterial chemotherapy of 5-fluorouracil and mitomycin C in the treatment of liver metastases of colorectal cancer.

AIM: Regional chemotherapy using hepatic artery catheters is a good method of treating patients with colorectal cancer liver metastases. We investigated the survival of patients with liver metastases from colorectal cancer using 5-fluorouracil (5-FU) and mitomycin C Cthrough implantable hepatic arterial infusion port. METHODS: Seventy-five patients with inoperable liver metastases from colorectal cancer were included between March, 1992 and November, 2001. We placed implantable hepatic arterial catheter (HAC) port by laparotomy. 5-FU, 1 000 mg/ m(2)/d continuous infusion for five days every four weeks, was delivered in the hepatic arterial catheter through the port. Mitomycin C, 30 mg/m(2)/d infusion in the first day every cycle through the port. Response to the treatment was evaluated by serial determinations of plasma CEA and imaging techniques consisting of computerized tomography and sonography of liver. RESULTS: Sixty-eight were performed hepatic artery chemotherapy and fifty-six were followed up among seventy-five HAC patients. Twenty-six patients(46.4 %) have responded and 4 complete remission were achieved. Eight patients (14.3 %) had stable liver metastases. Twenty-two patients (39.3 %) were progressed with increased tumor size and number. Twenty-nine patients(51.8%) had a decreased serum CEA level, while 10 patients (17.9 %) were stable and 17 patients (30.4 %) had an increased serum CEA level. There were no operative death in this series. Complications, which occurred in 18 patients (32.1 %), were as followed: hepatic artery thrombosis in 11, Upper gastric and intestinal bleeding in 3, liver abscess in 1, pocket infection in 1, cholangitis in 1, and hepatic artery pseudo-aneurysm in one patient. CONCLUSION: Combined infusion of 5-FU and mitomycin C by hepatic artery catheter port is an effective treatment for liver metastases from colorectal cancer. The high response and lower complication rates prove the adjuvant treatment of colorectal cancer with this treatment.