[Identification of quality markers of Gei Herba based on analytic hierarchy process-entropy weight method and network pharmacology].

Analytic hierarchy process(AHP)-entropy weight method(EWM) and network pharmacology were employed to identify the potential quality markers(Q-markers) of Gei Herba. According to the new concept of Q-markers in traditional Chinese medicine(TCM), the AHP-EWM was applied to quantitatively identify the Q-markers of Gei Herba. The AHP was used for the weight analysis of primary indicators(factor layer), and the EWM for the analysis of literature and experimental data of secondary indicators(control layer). In addition, network pharmacology was employed to build the "component-target-disease-efficacy" network for Gei Herba, and the components showing strong associations with the Qi-replenishing, spleen-invigorating, blood-tonifying, Yin-nourishing, lung-moistening, and phlegm-resolving effects of Gei Herba were screened out. According to the results of AHP-EWM and network pharmacology, four components, i.e., ellagic acid, gallic acid, gemin G, and gemin C, were finally identified as potential Q-markers of Gei Herba. In this study, the AHP-EWM and network pharmacology were employed to screen the Q-markers of Gei Herba, which provided ideas for the quantitative evaluation and identification of Q-markers of TCM.

Role of XBP1 in regulating the progression of non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Non-alcoholic steatohepatitis (NASH) is associated with the dysregulation of lipid metabolism and hepatic inflammation, though the underlying mechanisms remain unclear. We aimed to investigate the role of X-box binding protein-1 (XBP1) in the progression of NASH. METHODS: Human liver tissues obtained from patients with NASH and controls were used to assess XBP1 expression. NASH models were developed in hepatocyte-specific Xbp1 knockout (Xbp1ΔHep), macrophage-specific Xbp1 knockout (Xbp1ΔMf), macrophage-specific Nlrp3 knockout, and wild-type (Xbp1FL/FL or Nlrp3FL/FL) mice fed with a high-fat diet for 26 weeks or a methionine/choline-deficient diet for 6 weeks. RESULTS: The expression of XBP1 was significantly upregulated in liver samples from patients with NASH. Hepatocyte-specific Xbp1 deficiency inhibited the development of steatohepatitis in mice fed the high-fat or methionine/choline-deficient diets. Meanwhile, macrophage-specific Xbp1 knockout mice developed less severe steatohepatitis and fibrosis than wild-type Xbp1FL/FL mice in response to the high-fat or methionine/choline-deficient diets. Macrophage-specific Xbp1 knockout mice showed M2 anti-inflammatory polarization. Xbp1-deleted macrophages reduced steatohepatitis by decreasing the expression of NLRP3 and secretion of pro-inflammatory cytokines, which mediate M2 macrophage polarization in macrophage-specific Xbp1 knockout mice. Steatohepatitis was less severe in macrophage-specific Nlrp3 knockout mice than in wild-type Nlrp3FL/FL mice. Xbp1-deleted macrophages prevented hepatic stellate cell activation by decreasing expression of TGF-ß1. Less fibrotic changes were observed in macrophage-specific Xbp1 knockout mice than in wild-type Xbp1FL/FL mice. Inhibition of XBP1 suppressed the development of NASH. CONCLUSION: XBP1 regulates the development of NASH. XBP1 inhibitors protect against steatohepatitis. Thus, XBP1 is a potential target for the treatment of NASH. LAY SUMMARY: XBP1 is a transcription factor that is upregulated in liver tissues of patients with non-alcoholic steatohepatitis (NASH). Conditional knockout of Xbp1 in hepatocytes resulted in decreased lipid accumulation in mice, while genetic deletion of Xbp1 in macrophages ameliorated nutritional steatohepatitis and fibrosis in mice. Pharmacological inhibition of XBP1 protects against steatohepatitis and fibrosis, highlighting a promising therapeutic strategy for NASH.

Isoform- and Cell Type-Specific Roles of Glycogen Synthase Kinase 3 N-Terminal Serine Phosphorylation in Liver Ischemia Reperfusion Injury.

Glycogen synthase kinase 3 (Gsk3) α and ß are both constitutively active and inhibited upon stimulation by N-terminal serine phosphorylation. Although roles of active Gsk3 in liver ischemia reperfusion injury (IRI) have been well appreciated, whether Gsk3 N-terminal serine phosphorylation has any functional significance in the disease process remains unclear. In a murine liver partial warm ischemia model, we studied Gsk3 N-terminal serine mutant knock-in (KI) mice and showed that liver IRI was decreased in Gsk3αS21A but increased in Gsk3ßS9A mutant KI mice. Bone marrow chimeric experiments revealed that the Gsk3α, but not ß, mutation in liver parenchyma protected from IRI, and both mutations in bone marrow-derived cells exacerbated liver injuries. Mechanistically, mutant Gsk3α protected hepatocytes from inflammatory (TNF-α) cell death by the activation of HIV-1 TAT-interactive protein 60 (TIP60)-mediated autophagy pathway. The pharmacological inhibition of TIP60 or autophagy diminished the protection of the Gsk3α mutant hepatocytes from inflammatory cell death in vitro and the Gsk3α mutant KI mice from liver IRI in vivo. Thus, Gsk3 N-terminal serine phosphorylation inhibits liver innate immune activation but suppresses hepatocyte autophagy in response to inflammation. Gsk3 αS21, but not ßS9, mutation is sufficient to sustain Gsk4 activities in hepatocytes and protect livers from IRI via TIP60 activation.

TGR5/Cathepsin E signaling regulates macrophage innate immune activation in liver ischemia and reperfusion injury.

The role and underlying mechanism of plasma membrane-bound G protein-coupled bile acid receptor (TGR5) in regulating macrophage innate immune activation during liver ischemia and reperfusion (IR) injury remains largely unclear. Here, we demonstrated that TGR5 depletion in myeloid cells aggravated liver injury with increased macrophage infiltration and enhanced inflammation in livers post-IR. While TGR5 deficiency enhanced mobility and proinflammatory M1 polarization of macrophages, TGR5 agonist enhanced the anti-inflammatory effect of TGR5 both in vivo and in vitro. Microarray profiling revealed that TGR5-deficient macrophages exhibited enhanced proinflammatory characteristics and cathepsin E (Cat E) was the most upregulated gene. Knockdown of Cat E abolished the enhanced mobility and shift of macrophage phenotypes induced by TGR5 depletion. Moreover, Cat E knockdown attenuated liver IR injury and liver inflammation in myeloid TGR5-deficient mice. In patients undergoing partial hepatectomy, IR stress promoted TGR5 activation of CD11b+ cells in peripheral blood mononuclear cells, correlating with the shift in macrophage M2 polarization. Ursodeoxycholic acid administration enhanced TGR5 activation and the trend in macrophage M2 polarization. Our results suggest that TGR5 attenuates proinflammatory immune activation by restraining macrophage migration and facilitating macrophage M2 polarization via suppression of Cat E and thereby protects against liver IR injury.

Hyperglycemia aggravates acute liver injury by promoting liver-resident macrophage NLRP3 inflammasome activation via the inhibition of AMPK/mTOR-mediated autophagy induction.

Although the detrimental effects of diabetes mellitus/hyperglycemia have been observed in many liver disease models, the function and mechanism of hyperglycemia regulating liver-resident macrophages, Kupffer cells (KCs), in thioacetamide (TAA)-induced liver injury remain largely unknown. In this study, we evaluated the role of hyperglycemia in regulating NOD-like receptor family pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting autophagy induction in KCs in the TAA-induced liver injury model. Type I diabetes/hyperglycemia was induced by streptozotocin treatment. Compared with the control group, hyperglycemic mice exhibited a significant increase in intrahepatic inflammation and liver injury. Enhanced NLRP3 inflammasome activation was detected in KCs from hyperglycemic mice, as shown by increased gene induction and protein levels of NLRP3, cleaved caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain and interleukin-1ß, compared with control mice. NLRP3 inhibition by its antagonist CY-09 effectively suppressed inflammasome activation in KCs and attenuated liver injury in hyperglycemic mice. Furthermore, inhibited autophagy activation was revealed by transmission electron microscope detection, decreased LC3B protein expression and p-62 protein degradation in KCs isolated from TAA-stressed hyperglycemic mice. Interestingly, inhibited 5' AMP-activated protein kinase (AMPK) but enhanced mammalian target of rapamycin (mTOR) activation was found in KCs from TAA-stressed hyperglycemic mice. AMPK activation by its agonist 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or mTOR signaling knockdown by small interfering RNA restored autophagy activation, and subsequently, inhibited NLRP3 inflammasome activation in KCs, leading to ultimately reduced TAA-induced liver injury in the hyperglycemic mice. Our findings demonstrated that hyperglycemia aggravated TAA-induced acute liver injury by promoting liver-resident macrophage NLRP3 inflammasome activation via inhibiting AMPK/mTOR-mediated autophagy. This study provided a novel target for prevention of toxin-induced acute liver injury under hyperglycemia.

RIP3 deficiency alleviates liver fibrosis by inhibiting ROCK1-TLR4-NF-κB pathway in macrophages.

Liver fibrosis is an important pathologic process in injured liver tissues. A protein kinase, receptor-interacting protein (RIP)3, plays a crucial role in mediating different diseases. However, the role of RIP3 in macrophages in liver fibrosis has not yet been studied. In our study, we found that RIP3 expression was up-regulated in liver tissues and macrophages of humans and mice with liver fibrosis. Absence of RIP3 in macrophages could alleviate inflammation and macrophage or neutrophil accumulation in mice after carbon tetrachloride (CCl4) or bile duct ligation (BDL) treatment. Importantly, RIP3 deficiency in macrophages could decrease CCl4-induced and BDL-induced liver fibrosis in mice. Moreover, RIP3 deficiency could inhibit the TLR4-NF-κB pathway through suppressing Rho-associated coiled-coil containing protein kinase (ROCK)1 in macrophages. To explore the connection of ROCK1 and RIP3 in macrophages of mice with liver fibrosis in vivo, ROCK1-overexpressed macrophages were infused to RIP3-deficient mice, which resulted in increased inflammation and liver fibrosis. In conclusion, our findings suggest that RIP3 plays a crucial proinflammatory role in liver fibrosis by regulating the ROCK1-TLR4-NF-κB signaling pathway in macrophages and therefore may be a potential therapeutic target for immune-mediated liver fibrosis.-Wei, S., Zhou, H., Wang, Q., Zhou, S., Li, C., Liu, R., Qiu, J., Shi, C., Lu, L. RIP3 deficiency alleviates liver fibrosis by inhibiting ROCK1-TLR4-NF-κB pathway in macrophages.

Magnetic nanoparticle hyperthermia for treating locally advanced unresectable and borderline resectable pancreatic cancers: the role of tumor size and eddy-current heating.

PURPOSE: Tumor volume largely determines the success of local control of borderline resectable and locally advanced pancreatic cancer with current therapy. We hypothesized that a tumor-mass normalized dose of magnetic nanoparticle hyperthermia (MNPH) with alternating magnetic fields (AMFs) reduces the effect of tumor volume for treatment. METHODS: 18 female athymic nude mice bearing subcutaneous MiaPaCa02 human xenograft tumors were treated with MNPH following intratumor injections of 5.5 mg Fe/g tumor of an aqueous suspension of magnetic iron-oxide nanoparticles. Mice were randomly divided into control (n = 5) and treated groups having small (0.15 ± 0.03 cm3, n = 4) or large (0.30 ± 0.06 cm3, n = 5) tumors. We assessed the clinical feasibility of this approach and of pulsed AMF to minimize eddy current heating using a finite-element method to solve a bioheat equation for a human-scale multilayer model. RESULTS: Compared to the control group, both small and large MiaPaCa02 subcutaneous tumors showed statistically significant growth inhibition. Conversely, there was no significant difference in tumor growth between large and small tumors. Both computational and xenograft models demonstrated higher maximum tumor temperatures for large tumors compared to small tumors. Computational modeling demonstrates that pulsed AMF can minimize nonspecific eddy current heating. CONCLUSIONS: MNPH provides an advantage to treat large tumors because the MION dose can be adjusted to increase power. Pulsed AMF, with adjusted treatment time, can enhance MNPH in challenging cases such as low MION dose in the target tissue and/or large patients by minimizing nonspecific eddy current heating without sacrificing thermal dose to the target. Nanoparticle heterogeneity in tumors remains a challenge for continued research.

Prolonged Ischemia Triggers Necrotic Depletion of Tissue-Resident Macrophages To Facilitate Inflammatory Immune Activation in Liver Ischemia Reperfusion Injury.

Although mechanisms of immune activation against liver ischemia reperfusion (IR) injury (IRI) have been studied extensively, questions regarding liver-resident macrophages, that is, Kupffer cells (KCs), remain controversial. Recent progress in the biology of tissue-resident macrophages implicates homeostatic functions of KCs. This study aims to dissect responses and functions of KCs in liver IRI. In a murine liver partial warm ischemia model, we analyzed liver-resident versus infiltrating macrophages by FACS and immunofluorescence staining. Our data showed that liver immune activation by IR was associated with not only infiltrations/activations of peripheral macrophages, but also necrotic depletion of KCs. Inhibition of receptor-interacting protein 1 (RIP1) by necrostatin-1s protected KCs from ischemia-induced depletion, resulting in the reduction of macrophage infiltration, suppression of proinflammatory immune activation, and protection of livers from IRI. The depletion of KCs by clodronate liposomes abrogated the effect of necrostatin-1s. Additionally, liver reconstitutions with KCs postischemia exerted anti-inflammatory/cytoprotective effects against IRI. These results reveal a unique response of KCs against liver IR, that is, RIP1-dependent necrosis, which constitutes a novel mechanism of liver inflammatory immune activation in the pathogenesis of liver IRI.

Precoagulation with microwave ablation for hepatic parenchymal transection during liver partial resection.

PURPOSE: To evaluate the feasibility of precoagulation with microwave ablation (MWA) for hepatic parenchymal transection during liver partial resection. METHODS: A total of 66 eligible patients were enrolled in this double-blind, randomized, controlled study. Patients were randomized to receive either the traditional clamp-crushing method (Control group) or the MWA precoagulation method (MWA group) for hepatic parenchymal transection during liver partial resection. The operative time, hepatic portal occlusion time, intraoperative blood loss and transfusion, postoperative complications and recovery outcomes were compared. RESULTS: Compared to the Control group, the MWA group had significantly less intraoperative blood loss. Fewer red blood cell transfusions were observed in the MWA group but without statistical significance. The MWA group showed significantly higher serum alanine aminotransferase and aspartate aminotransferase levels at day 1 postoperatively, but no differences between the MWA and Control groups were found at days 3 and 7. There were no significant differences in terms of operative time, hepatic portal occlusion time, postoperative total bilirubin levels, human albumin solution consumption or length of hospital stay. Postoperative complications such as impaired renal function, pyrexia, admission to ICU, abscess, biliary leakage, intrahepatic and distant tumor recurrence and in-hospital mortality were comparable between the two groups. CONCLUSION: Precoagulation with MWA reduced intraoperative blood loss with similar postoperative complications, providing a safe, effective, novel alternative for hepatic parenchymal transection during liver partial resection. Additional results from larger series are recommended to confirm these findings.

Glycogen synthase kinase 3ß promotes liver innate immune activation by restraining AMP-activated protein kinase activation.

BACKGROUND & AIMS: Glycogen synthase kinase 3ß (Gsk3ß [Gsk3b]) is a ubiquitously expressed kinase with distinctive functions in different types of cells. Although its roles in regulating innate immune activation and ischaemia and reperfusion injuries (IRIs) have been well documented, the underlying mechanisms remain ambiguous, in part because of the lack of cell-specific tools in vivo. METHODS: We created a myeloid-specific Gsk3b knockout (KO) strain to study the function of Gsk3ß in macrophages in a murine liver partial warm ischaemia model. RESULTS: Compared with controls, myeloid Gsk3b KO mice were protected from IRI, with diminished proinflammatory but enhanced anti-inflammatory immune responses in livers. In bone marrow-derived macrophages, Gsk3ß deficiency resulted in an early reduction of Tnf gene transcription but sustained increase of Il10 gene transcription on Toll-like receptor 4 stimulation in vitro. These effects were associated with enhanced AMP-activated protein kinase (AMPK) activation, which led to an accelerated and higher level of induction of the novel innate immune negative regulator small heterodimer partner (SHP [Nr0b2]). The regulatory function of Gsk3ß on AMPK activation and SHP induction was confirmed in wild-type bone marrow-derived macrophages with a Gsk3 inhibitor. Furthermore, we found that this immune regulatory mechanism was independent of Gsk3ß Ser9 phosphorylation and the phosphoinositide 3-kinase-Akt signalling pathway. In vivo, myeloid Gsk3ß deficiency facilitated SHP upregulation by ischaemia-reperfusion in liver macrophages. Treatment of Gsk3b KO mice with either AMPK inhibitor or SHP small interfering RNA before the onset of liver ischaemia restored liver proinflammatory immune activation and IRI in these otherwise protected hosts. Additionally, pharmacological activation of AMPK protected wild-type mice from liver IRI, with reduced proinflammatory immune activation. Inhibition of the AMPK-SHP pathway by liver ischaemia was demonstrated in tumour resection patients. CONCLUSIONS: Gsk3ß promotes innate proinflammatory immune activation by restraining AMPK activation. LAY SUMMARY: Glycogen synthase kinase 3ß promotes macrophage inflammatory activation by inhibiting the immune regulatory signalling of AMP-activated protein kinase and the induction of small heterodimer partner. Therefore, therapeutic targeting of glycogen synthase kinase 3ß enhances innate immune regulation and protects liver from ischaemia and reperfusion injury.

Application of microwave ablation in the emergent control of intraoperative life-threatening tumor hemorrhage during hepatic surgeries.

PURPOSE: This study was designed to evaluate the efficacy and safety of microwave ablation (MWA) in the treatment of intraoperative life-threatening tumour haemorrhage during hepatic surgeries. METHODS: Three cases of MWA application in the emergent control of life-threatening hepatic tumour haemorrhage were analysed and reported. RESULTS: Satisfactory hemostasis for hepatic tumour rupture was achieved by MWA in all three cases. No major complications, such as post-operative haemorrhage, bile duct injury, liver abscess, colon perforation, skin burns, tumour seeding or renal dysfunction, were identified. CONCLUSIONS: MWA may be a feasible, effective and simple strategy for the emergent control of intraoperative hepatic tumour bleeding. To the best of our knowledge, this study represents the first reported cases of this novel application of MWA.

An optimised spectrophotometric assay for convenient and accurate quantitation of intracellular iron from iron oxide nanoparticles.

We report the development and optimisation of an assay for quantitating iron from iron oxide nanoparticles in biological matrices by using ferene-s, a chromogenic compound. The method is accurate, reliable and can be performed with basic equipment common to many laboratories making it convenient and inexpensive. The assay we have developed is suited for quantitation of iron in cell culture studies with iron oxide nanoparticles, which tend to manifest low levels of iron. The assay was validated with standard reference materials and with inductively coupled plasma-mass spectrometry (ICP-MS) to accurately measure iron concentrations ∼1 × 10-6 g in about 1 × 106 cells (∼1 × 10-12 g Fe per cell). The assay requires preparation and use of a working solution to which samples can be directly added without further processing. After overnight incubation, the absorbance can be measured with a standard UV/Vis spectrophotometer to provide iron concentration. Alternatively, for expedited processing, samples can be digested with concentrated nitric acid before addition to the working solution. Optimization studies demonstrated significant deviations accompany variable digestion times, highlighting the importance to ensure complete iron ion liberation from the nanoparticle or sample matrix to avoid underestimating iron concentration. When performed correctly, this method yields reliable iron ion concentration measurements to ∼2 × 10-6 M (1 × 10-7 g/ml sample).

Plasma membrane-bound G protein-coupled bile acid receptor attenuates liver ischemia/reperfusion injury via the inhibition of toll-like receptor 4 signaling in mice.

The plasma membrane-bound G protein-coupled bile acid receptor (TGR5) displays varied levels of expression in different tissues. TGR5-induced liver protection has been demonstrated during several liver diseases, except during ischemia/reperfusion injury (IRI). Male adult wild-type and TGR5 knockout (KO) mice were subjected to liver partial warm ischemia/reperfusion. Hepatic injury was evaluated based on serum alanine aminotransferase and serum aspartate aminotransferase. Liver histological injury and inflammatory cell infiltration were evaluated in tissue sections using liver immunohistochemical analysis. We used quantitative real-time polymerase chain reaction to analyze the liver expression of inflammatory cytokines. The toll-like receptor 4 (TLR4) signaling pathway and its related apoptotic molecules were investigated after reperfusion. Moreover, the effect of TGR5 on inflammation was determined with TGR5+/+ or TGR5-/- primary bone marrow-derived macrophages in vitro. TGR5 significantly attenuated liver damage after IRI. As demonstrated by in vivo experiments, TGR5 significantly reduced the up-regulation of the TLR4-nuclear factor kappa B (NF-κB) pathway and inhibited caspase 8 activation after IRI. Later experiments showed that TGR5 KO significantly increased the expression of TLR4-NF-κB signaling molecules and promoted hepatocellular apoptosis. In addition, in vitro experiments showed that overexpression of 6alpha-ethyl-23(S)-methylcholic acid (INT-777)-activated TGR5 directly down-regulated tumor necrosis factor α (TNF-α) and interleukin (IL) 6 expression but up-regulated IL10 expression in hypoxia/reoxygenation-induced primary TGR5+/+ macrophages. Moreover, the expression of TLR4-NF-κB signaling molecules was significantly inhibited by the activation of TGR5. Importantly, these results were completely reversed in primary TGR5-/- macrophages. This work is the first to provide evidence for a TGR5-inhibited inflammatory response in IRI through suppression of the TLR4-NF-κB pathway, which may be critical in reducing related inflammatory molecules and modulating innate inflammation. Liver Transplantation 23:63-74 2017 AASLD.

Ropivacaine wound infiltration: a fast-track approach in patients undergoing thoracotomy surgery.

BACKGROUND: Postoperative pain impairs enhanced recovery in patients after various surgeries. Local use of ropivacaine has become an effective strategy for postoperative pain management. The aim of this study was to assess the effectiveness and safety of wound infiltration with ropivacaine for postoperative analgesia as a fast-track approach in patients undergoing thoracotomy surgery. MATERIALS AND METHODS: Forty adult patients with esophageal cancer scheduled for selective thoracotomy surgery were enrolled in this double-blind, randomized, controlled study. Patients were randomized (1:1) to receive ropivacaine or placebo wound infiltration before incision closure. Numerical rating score (NRS), postoperative analgesics consumption, length of hospital stay, time to anal exsufflation, defecation, ambulation, and patient satisfaction scores were recorded. Side effects including allergic reaction, nausea, vomiting, wound infection, and pneumonia were also assessed. RESULTS: NRS was significantly decreased in the ropivacaine group with less consumption of postsurgery analgesics. The ropivacaine group also showed shorter postoperative hospital stays, earlier anal exsufflation and ambulation, and higher patient satisfaction scores. However, there were no significant differences between the two groups regarding time of defecation. No allergic reactions occurred in either group. The incidences of nausea, vomiting, wound infection, and pneumonia were similar. CONCLUSIONS: The present study showed that ropivacaine wound infiltration could be a safe and effective fast-track approach for patients undergoing thoracotomy surgery.

Image-guided thermal therapy with a dual-contrast magnetic nanoparticle formulation: A feasibility study.

PURPOSE/OBJECTIVE: The aim of this study was to develop and investigate the properties of a magnetic iron oxide nanoparticle-ethiodised oil formulation for image-guided thermal therapy of liver cancer. MATERIALS AND METHODS: The formulation comprises bionised nano-ferrite (BNF) nanoparticles suspended in ethiodised oil, emulsified with polysorbate 20 (BNF-lip). Nanoparticle size was measured via photon correlation spectroscopy and transmission electron microscopy. In vivo thermal therapy capability was tested in two groups of male Foxn1(nu) mice bearing subcutaneous HepG2 xenograft tumours. Group I (n = 12) was used to screen conditions for group II (n = 48). In group II, mice received one of BNF-lip (n = 18), BNF alone (n = 16), or PBS (n = 14), followed by alternating magnetic field (AMF) hyperthermia, with either varied duration (15 or 20 min) or amplitude (0, 16, 20, or 24 kA/m). Image-guided fluoroscopic intra-arterial injection of BNF-lip was tested in New Zealand white rabbits (n = 10), bearing liver VX2 tumours. The animals were subsequently imaged with CT and 3 T MRI, up to 7 days post-injection. The tumours were histopathologically evaluated for distribution of BNF-lip. RESULTS: The BNF showed larger aggregate diameters when suspended in BNF-lip, compared to clear solution. The BNF-lip formulation produced maximum tumour temperatures with AMF >20 kA/m and showed positive X-ray visibility and substantial shortening of T1 and T2 relaxation time, with sustained intratumoural retention up to 7 days post-injection. On pathology, intratumoural BNF-lip distribution correlated well with CT imaging of intratumoural BNF-lip distribution. CONCLUSION: The BNF-lip formulation has favourable thermal and dual imaging capabilities for image-guided thermal therapy of liver cancer, suggesting further exploration for clinical applications.

Bromopyridone Nucleotide Analogues, Anoxic Selective Radiosensitizing Agents That Are Incorporated in DNA by Polymerases.

Ionizing radiation is frequently used to kill tumor cells. However, hypoxic solid tumor cells are more resistant to this treatment, providing the impetus to develop molecules that sensitize cells to ionizing radiation. 5-Bromo-2'-deoxyuridine (BrdU) has been investigated as a radiosensitizing agent in the lab and clinic for almost 5 decades. Recent reports that BrdU yields DNA interstrand cross-links (ICLs) in non-base-paired regions motivated us to develop radiosensitizing agents that generate cross-links in duplex DNA selectively under anoxic conditions. 4-Bromo- and 5-bromopyridone analogues of BrdU were synthesized and incorporated into oligonucleotides via solid-phase synthesis. Upon irradiation, these molecules yield DNA interstrand cross-links under anaerobic conditions. The respective nucleotide triphosphates are substrates for some DNA polymerases. ICLs are produced upon irradiation under anoxic conditions when the 4-bromopyridone is present in a PCR product. Because the nucleoside analogue is a poor phosphorylation substrate for human deoxycytidine kinase, a pro-nucleotide form of the 4-bromopyridone was used to incorporate this analogue into cellular DNA. Despite these efforts, the 4-bromopyridone nucleotide was not detected in cellular DNA. Although these molecules are improvements over previously reported nucleotide analogues designed to be hypoxic radiosensitizing agents, additional advances are needed to create molecules that function in cells.

Magnetic nanoparticle hyperthermia enhances radiation therapy: A study in mouse models of human prostate cancer.

PURPOSE: We aimed to characterise magnetic nanoparticle hyperthermia (mNPH) with radiation therapy (RT) for prostate cancer. METHODS: Human prostate cancer subcutaneous tumours, PC3 and LAPC-4, were grown in nude male mice. When tumours measured 150 mm3 magnetic iron oxide nanoparticles (MIONPs) were injected into tumours to a target dose of 5.5 mg Fe/cm3 tumour, and treated 24 h later by exposure to alternating magnetic field (AMF). Mice were randomly assigned to one of four cohorts to characterise (1) intratumour MIONP distribution, (2) effects of variable thermal dose mNPH (fixed AMF peak amplitude 24 kA/m at 160 ± 5 kHz) with/without RT (5 Gy), (3) effects of RT (RT5: 5 Gy; RT8: 8 Gy), and (4) fixed thermal dose mNPH (43 °C for 20 min) with/without RT (5 Gy). MIONP concentration and distribution were assessed following sacrifice and tissue harvest using inductively coupled plasma mass spectrometry (ICP-MS) and Prussian blue staining, respectively. Tumour growth was monitored and compared among treated groups. RESULTS: LAPC-4 tumours retained higher MIONP concentration and more uniform distribution than did PC3 tumours. AMF power modulation provided similar thermal dose for mNPH and combination therapy groups (CEM43: LAPC-4: 33.6 ± 3.4 versus 25.9 ± 0.8, and PC3: 27.19 ± 0.7 versus 27.50 ± 0.6), thereby overcoming limitations of MIONP distribution and yielding statistically significant tumour growth delay. CONCLUSION: PC3 and LAPC-4 tumours represent two biological models that demonstrate different patterns of nanoparticle retention and distribution, offering a model to make comparisons of these effects for mNPH. Modulating power for mNPH offers potential to overcome limitations of MIONP distribution to enhance mNPH.

Irreversible inhibition of DNA polymerase ß by small-molecule mimics of a DNA lesion.

Abasic sites are ubiquitous DNA lesions that are mutagenic and cytotoxic but are removed by the base excision repair pathway. DNA polymerase ß carries out two of the four steps during base excision repair, including a lyase reaction that removes the abasic site from DNA following incision of its 5'-phosphate. DNA polymerase ß is overexpressed in cancer cells and is a potential anticancer target. Recently, DNA oxidized abasic sites that are produced by potent antitumor agents were shown to inactivate DNA polymerase ß. A library of small molecules whose structures were inspired by the oxidized abasic sites was synthesized and screened for the ability to irreversibly inhibit DNA polymerase ß. One candidate (3a) was examined more thoroughly, and modification of its phosphate backbone led to a molecule that irreversibly inactivates DNA polymerase ß in solution (IC50 ≈ 21 µM), and inhibits the enzyme's lyase activity in cell lysates. A bisacetate analogue is converted in cell lysates to 3a. The bisacetate is more effective in cell lysates, more cytotoxic in prostate cancer cells than 3a and potentiates the cytotoxicity of methyl methanesulfonate between 2- and 5-fold. This is the first example of an irreversible inhibitor of the lyase activity of DNA polymerase ß that works synergistically with a DNA damaging agent.