OS08.7.A Lomustine and the immunocytokine L19TNF are a promising treatment combination for recurrent glioblastoma

Background

Treatment options for recurrent glioblastoma are limited and with the possible exception of regorafenib, no agent has demonstrated superior activity to lomustine. Therefore, there is an urgent need for more effective treatment strategies for recurrent glioblastoma. Here, we investigated different treatment combinations based on the tumor-stroma targeting antibody-cytokine fusion protein L19TNF in preclinical glioma models and translated the most effective treatment combination to patients with recurrent glioblastoma.

Material and Methods

Orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity of L19TNF in combination with anti-PD1, bevacizumab or lomustine. Tumor growth was monitored by MRI. Flow cytometry and microscopy were used to characterize tumor-infiltrating-immune cells. MHC immunoaffinity purification and mass spectrometry were used to characterize the MHC immunopeptidome. Genetic mouse models were used to study immune-dependent effects. Subsequently, we translated the most efficient treatment combination to patients with recurrent glioblastoma within a phase I/II clinical trial (NCT04573192).

Results

The combination of L19TNF and lomustine demonstrated strong synergistic anti-tumor activity in two immunocompetent orthotopic glioma models and cured a majority of tumor-bearing mice. In contrast, combinations with anti-PD-1 or bevacizumab had only limited anti-glioma activity. Furthermore, compared to the monotherapies, the combination of L19TNF and lomustine led to the strongest increase in tumor-infiltrating lymphoid cells as demonstrated by flow cytometry and microsopy and to the highest number of peptides presented in the context of MHC-I. The treatment effect was abrograted in different genetic immunodeficient mouse models. The treatment combination of L19TNF and lomustine was well tolerated in the first patients treated within a phase I/II clinical trial and we observed partial tumor responses also in patients with an unmethylated MGMT promoter.

Conclusion

The combination of L19TNF and lomustine demonstrated promising anti-glioma activity and patients are currently recruited within a phase I/II clinical trial for patients with recurrent glioblastoma.

Childhood consumption of ultra-processed foods and adiposity trajectories: a UK birth cohort study

Background

Worldwide consumption of ultra-processed foods (UPFs) is continued to rise. Growing evidence has linked higher consumption with elevated risks of obesity and non-communicable diseases in adults. However, the influence of UPFs on long-term adiposity trajectories have not been evaluated in children.

Methods

Prospective birth cohort data were obtained from the Avon Longitudinal Study of Parents and Children. English children with baseline dietary intakes from 3-day food diaries and repeated adiposity measures were followed up from ages 7-24 years. Outcomes included body mass index (BMI), weight, waist circumference (WC), fat mass index (FMI) and body fat percentage. UPFs were identified using the NOVA food classification. Child's consumption of UPFs was derived as a percentage of its weight contribution (gram per day) in the total diet and categorised into quintiles. Longitudinal associations were assessed using linear growth curve models and adjusted for study covariates.

Results

Of the 9025 children followed up over a median (IQR) of 10.2 (5.2-16.4) years. Trajectories of BMI, FMI, weight and WC increased by an additional 0.06 (95% CI, 0.04-0.08) kg/m2, 0.03 (0.01-0.05) kg/m2, 0.20 (0.11-0.28) kg and 0.17 (0.11-0.22) cm per year among those in the highest (vs. lowest) quintile of UPF consumption. Evidence of dose-response relationships were consistently observed with those in the two highest quintiles of UPF consumption showing significantly more rapid progression of BMI, weight, and WC.

Conclusions

Radical and effective public health actions that reduce children's exposure and consumption of UPFs are urgently needed to address the obesity epidemic in England and internationally.

Funding: CM and EV are funded by the National Institute for Health Research (NIHR) School for Public Health Research (SPHR), Grant Reference Number PD-SPH-2015. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.

Key messages

Children with highest (vs. lowest) quintile of ultra-processed food consumption had more rapid regression of BMI, FMI, weight and waist circumference from ages 7-24 years. Dose-response relationships were consistently observed in the two highest quintile of ultra-processed food consumption showing more rapid progression of BMI, weight and waist circumference.

P12.08 Immunocytokines are a novel immunotherapeutic approach against glioblastoma

BACKGROUND

Glioblastoma is the most common malignant primary brain tumor in adults with an urgent need for novel treatment options. The administration of pro-inflammatory cytokines could be a potent immunotherapeutic approach to shift the balance between tumor-associated immunosuppression and immune activation. However, the systemic administration of therapeutically active doses of pro-inflammatory cytokines is not feasible due to toxic side effects and there is a need for strategies that enable a targeted delivery of pro-inflammatory cytokines to the tumor site.

METHODS

We investigated different antibody-cytokine fusion products that enable a targeted delivery of interleukin (IL)-2, IL-12 or tumor necrosis factor (TNF)-α to the tumor site by binding to a tumor-specific epitope of fibronectin. We investigated the expression of this tumor-specific epitope ex vivo in tumor-bearing mouse brains and human glioblastoma samples. Subsequently, we assessed the anti-tumor activity of IL-2, IL-12 or TNF-α fused to an antibody targeting this tumor-specific epitope in orthotopic syngeneic mouse glioma models.

RESULTS

The tumor-specfic extra domain B of fibronectin is expressed in murine glioma models and human glioblastoma samples. A fluorochrome-labeled antibody targeting this tumor-specific epitope accumulated at the tumor site in the brain in vivo upon systemic administration. IL-2, IL-12, or TNF-α fused to this antibody conferred a survival benefit in orthotopic tumor-bearing mice and cured a fraction of tumor-bearing mice. Mechanistically, antibody-fused TNF-α induced tumor necrosis and increased the activation of tumor-infiltrating natural killer (NK) cells, whereas antibody-fused IL-12 mainly boosted an anti-tumor immune response mediated by NK cells and T cells.

CONCLUSION

We demonstrate the expression of a tumor-specific epitope of fibronectin in glioblastoma and exploit this for the targeted delivery of IL-2, IL-12 or TNF-α to the tumor site. Our preclinical assessments indicate potent anti-tumor activity in orthotopic, syngneic glioma mouse models and reveal the mode of action for the different immunocytokines. Based on these findings, we initiated a phase I/II clinical trial in patients with recurrent glioma to investigate the targeted delivery of TNF-α (ClinicalTrials.gov identifier NCT03779230).

Comparison of Pig, Human and Rat Hepatocytes as a Source of Liver Specific Metabolic Functions in Culture Systems - Implications for Use in Bioartificial Liver Devices

The limited availability of human hepatocytes results in the use of animal cells in most bioartificial liver support devices. In the present work, clinically relevant liver specific metabolic activities were compared in rat, pig and human hepatocytes cultured on liver-derived biomatrix to optimize the expression of differentiated functions. Pig hepatocytes showed higher rates of diazepam metabolism (2.549±0.821 μg/h/million cells vs. 0.474±0.079 μg/h/million cells rats, p<0.005, and vs. 0.704±0.171 μg/h/million cells in man, p<0.005) and of bilirubin conjugation (21.60116±8.433237 μmoles/l/24 h vs. 6.786809±2.983758 in man, p<0.001 and vs. 9.956538±1.781016 μmoles/l/24 h in rats, p<0.005). Urea synthesis was similar in pig and in human hepatocytes (150±46.3 vs. 144.8±21.46 nmoles/h/million cells) and it was lower in rats (84.38±35.2; p<0.001 vs. man, p<0.02 vs. pig). High liver specific metabolic activities in cultured pig hepatocytes further support their use as a substitue for human cells in bioartificial liver devices

Palliative Treatment of Hepatocellular Carcinoma with Transcatheter Arterial Embolization

Thirty-three consecutive patients with previously untreated hepatocellular carcinoma (HCC) and 6 patients with recurrent HCC were treated with transcatheter arterial embolization (TAE). The patients were not eligible for surgical resection or percutaneous ethanol injection. TAE was performed with Lipiodol Ultra-Fluid, epidoxorubicin and Gelfoam, with a mean of 1.7 treatments per patient. CT was performed 15 days after TAE. The mean cumulative survival was 14.2 months in patients with previously untreated HCC. The survival of patients stages Okuda I and II did not differ significantly (p > 0.05); tumor size did not affect survival (p > 0.05). Two patients with recurrent HCC died 7.0 and 9.3 months after the diagnosis of tumor recurrence; the remaining 4 patients are still alive with a maximum follow-up of 22.5 months from the diagnosis of HCC recurrence. Ten complications occurred in 8 patients, and were controlled by medical therapy. Eleven patients died during the study; no death was related to TAE. The series was not randomized, but comparison with the natural history of HCC suggests that TAE is effective as palliative treatment of advanced or recurrent HCC.

Different tissue distribution properties for glycosylation variants of fusion proteins containing the p40 subunit of murine interleukin-12

Antibody-based fusion proteins are gaining increasing importance for therapeutic applications, but the impact of glycosylation on in vivo biopharmaceutical performance is not always completely understood. In this article, we have analyzed biochemical and pharmaceutical properties of fusion proteins, consisting of the F8 antibody (specific to the EDA domain of fibronectin, a marker of tissue remodeling and of angiogenesis) and of the p40 subunit of interleukin-12, an inhibitor of inflammation. The corresponding fusion protein (F8-IL12p40), which inhibits colitis development in mice, is a glycosylated protein with suboptimal disease targeting properties in vivo Since the protein was extensively glycosylated, as evidenced by PNGase F treatment and mass spectrometric analysis, we mutated four asparagine residues in various combinations. The corresponding proteins exhibited similar biochemical and antigen-binding properties, but differences in thermal stability and bioactivity. Asparagine mutations did not lead to recovery of disease targeting performance in vivo, as evidenced by quantitative biodistribution studies with radioiodinated protein preparations in tumor-bearing mice. By contrast, an almost complete recovery of targeting was achieved with an enzymatically deglycosylated protein preparation. These findings reinforce the concept that different glycostructures can have an impact on tissue distribution properties.

F8-SIP mediated targeted photodynamic therapy leads to microvascular dysfunction and reduced glioma growth

The extra domain A (ED A) of fibronectin has been identified as a tumor vessel specific neovascular marker in glioma. Antibody based vascular targeting against ED A of fibronectin allows precise accumulation of photosensitizer in glioma microvasculature and thereby promises to overcome drawbacks of current photodynamic therapy (PDT) for glioma treatment. Our aim was to characterize microcirculatory consequences of F8-small immunoprotein (SIP) mediated PDT by intravital microscopy (IVM) and to analyze the effects on glioma growth. For IVM SF126 glioma cells were implanted into dorsal skinfold-chamber of nude mice. PDT was performed after intravenous injection of photosensitizer (PS)-coupled F8-SIP or PBS (n = 4). IVM was performed before and after PDT for 4 days. Analysis included total and functional (TVD, FVD) vessel densities, perfusion index (PI), microvascular permeability and blood flow rate (Q). To assess tumor growth SF126 glioma cells were implanted subcutaneously. PDT was performed as a single and repetitive treatment after PS-F8-SIP injection (n = 5). Subcutaneous tumors were treated after uncoupled F8-SIP injection as control group (n = 5). PDT induced microvascular stasis and thrombosis with reduced FVD (24 h: 115.98 ± 0.7 vs. 200.8 ± 61.9 cm/cm(2)) and PI (39 ± 11 vs. 70 ± 10 %), whereas TVD was not altered (298 ± 39.2 vs. 278.2 ± 51 cm/cm(2)). Microvascular dysfunction recovered 4 days after treatment. Microvascular dysfunction led to a temporary reduction of glioma growth in the first 48 h after treatment with complete recovery 5 days after treatment. Repetitive PDT resulted in sustained reduction of tumor growth. F8-SIP mediated PDT leads to microvascular dysfunction and reduced glioma growth in a preclinical glioma model with recovery of microcirculation 4 days after treatment. Repetitive application of PDT overcomes microvascular recovery and leads to prolonged antiglioma effects.

Survival benefit of transplantation for recurrence of hepatocellular carcinoma after liver resection

BACKGROUND

Liver transplantation (LT) for hepatocellular carcinoma (HCC) can be used for tumor recurrence after liver resection (LR) both for initially transplant-eligible patients as conventional salvage therapy (ST) and for non-transplant-eligible patients (beyond Milan criteria) with a goal of downstaging (DW). The aim of this study was to compare the intention-to-treat (ITT) survival rates of patients who are listed for LT, according to these two strategies.

METHODS

We analyzed a prospective database of 399 consecutive patients who underwent hepatic resection for HCC from 2002 to 2011 to identify patients included in the waiting list for tumor recurrence. Intention-to-treat (ITT) survivals were compared with those of patients resected for HCC within and beyond Milan criteria in the same period and not included in the LT waiting list.

RESULTS

The study group consisted of 42 patients, 28 in the ST group (within Milan) and 14 in the DW group (beyond Milan). The 5-year ITT survival rate was similar between the 2 groups, being 64% for ST and 60% for DW (P=.84). Twenty-five patients (15 ST and 10 DW) underwent LT, 13 (10 ST and 3 DW) were still awaiting LT, 4 (3 ST and 1 DW) dropped out of the waiting list because of tumor progression, and 7 (5 ST [33%] and 2 DW [20%]) had tumor recurrence. The 5-year ITT survival of ST patients was similar to that of 252 in-Milan HCC patients resected only (P=.3), whereas 5-year ITT survival of DW patients was significantly higher (P<.01) than that of 105 beyond-Milan HCC patients resected only.

CONCLUSIONS

LR seems to be a safe and effective therapy both as alternative to transplantation and as downstaging strategy for intermediate-advanced HCC. The survival benefit of salvage LT, however, seems to be higher in the 2nd than in the 1st group.

Targeted ED-B fibronectin SPECT in vivo imaging in experimental atherosclerosis

AIM

The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. This study evaluated whether [(99m)Tc]-conjugated AP39 ([(99m)Tc]-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice.

METHODS

Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting [(99m)Tc]-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry.

RESULTS

In vivo [(99m)Tc]-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01).

CONCLUSION

[(99m)Tc]-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.

Alcohol abuse and de novo tumors in liver transplantation

INTRODUCTION

Organ transplant recipients show an increased incidence of cancer ranging from 4% to 16% owing to several causes: immunosuppression, viral infection, individual predisposition, and so on.

MATERIALS AND METHODS

We retrospectively reviewed the records of 43/683 (6.3%) recipients of 734 liver transplants performed from November 1991 to November 2008 who experienced a de novo neoplasm.

CONCLUSION

Alcohol abuse significantly increased the rate of all de novo neoplasms and particularly pharyngogastroesophageal cancers among population of liver transplant recipients. Minimization of immunosuppressive therapy is necessary to reduce the risk of a de novo neoplasm. Strict posttransplant follow-up is required to identify early gastroenteric tumors.

Progression of hepatocellular carcinoma before liver transplantation: dropout or liver transplantation?

BACKGROUND

Tumor progression before liver transplantation (OLT) is the main cause of dropout from the waiting list (WL) of patients with hepatocellular carcinoma (HCC). The aim of this study was to show a correlation between adopted dropout criteria and dropout/intention-to-treat survival rates of WL HCC patients.

METHODS

The study period was 2000 to 2007. The dropout criteria were macroscopic vascular invasion, metastases, or a poorly differentiated tumor. Adult patients with benign chronic liver disease enlisted for primary OLT in the same period represented the control group.

RESULTS

Dropout probability of study (n = 128) versus control group (n = 377) subjects was similar: namely, 12% at 1 year in both groups (P = NS). Intention-to-treat survival curve of the HCC group overlapped that of the benign group (5-year survival rates were 73% and 71%, respectively; P = NS). At the time of listing, 103 study group patients were within the Milan criteria (MC): among these patients, 29 (28%) showed tumor progression beyond MC before OLT. Simulating the dropout of these 29 patients at the time of diagnosis of tumor progression, we compared the dropout probability of the 103 patients within MC with that of the control group. As a result, the 1- and 2-year dropout rates became 37% and 53%, respectively, in the study group, which were significantly higher than those in the controls (P < .01).

CONCLUSION

HCC patients on the WL showed a significantly greater dropout rate than subjects with benign cirrhosis when too restrictive radiologic dropout criteria were used. The adoption of criteria more related to biological aggressiveness of a tumor decreased the dropout risk for HCC patients without impairing their intention-to-treat survival rates.

Measured anatomical distributions of solar UVR on strawberry production workers in Italy

The exposure of outdoor workers to solar ultraviolet radiation (UVR) has been known for some time. Measurements of erythemally weighted UVR are usually related to days of exposure and to the anatomical distribution of UVR on the human body. The aim of this research is to describe the UVR exposure of workers during a strawberry production cycle in order to assess the UVR hazard and to identify the highest exposure in the anatomical distribution of UVR on the body during an entire agricultural production cycle. This research was carried out on the experimental farm (Azienda Agraria Didattico-Sperimentale) of Università Politecnica delle Marche in Agugliano, Italy. A spectrometer was used to measure UVR, and electronic dosimeters were used to record UVR exposure. The measurements were carried out on all working days of the strawberry production cycle in 2012 during daily peak UVR levels. The daily UVR exposure geometric mean and the percentage ambient UVR in the strawberry production cycle were calculated and analyzed to assess the hazard for workers during the entire production cycle. The nape of the neck was the anatomical site most exposed to UVR. The mean daily UVR exposure on the nape of the neck was higher than 1.50 SED, the minimum value required to produce perceptible erythema in unacclimatized white skin, and a maximum value of 2.29 SED was measured. Real-time exposure data suggest that it may be useful to remind workers of the risks associated with UVR exposure.

Selective targeting of tumour neovasculature by a radiohalogenated human antibody fragment specific for the ED-B domain of fibronectin

Angiogenesis is a characteristic feature of many aggressive tumours and other disorders. Antibodies capable of binding to new blood vessels, but not to mature vessels, could be used as selective targeting agents for immunoscintigraphic and radioimmunotherapeutic applications. Here we show that scFv(L19), a recombinant human antibody fragment with sub-nanomolar affinity for the ED-B domain of fibronectin, a marker of angiogenesis, can be stably labelled with iodine-125 and astatine-211 with full retention of immunoreactivity, using a trimethyl-stannyl benzoate bifunctional derivative. Biodistribution studies in mice bearing two different types of tumour grafted subcutaneously, followed by ex vivo micro-autoradiographic analysis, revealed that scFv(L19) rapidly localises around tumour blood vessels, but not around normal vessels. Four hours after intravenous injection of the stably radioiodinated scFv(L19), tumour to blood ratios were 6:1 in mice bearing the F9 murine teratocarcinoma and 9:1 in mice bearing an FE8 rat sarcoma. As expected, all other organs (including kidney) contained significantly less radioactivity than the tumour. Since the ED-B domain of fibronectin has an identical sequence in mouse and man, scFv(L19) is a pan-species antibody and the results presented here suggest clinical utility of radiolabelled scFv(L19) for the scintigraphic detection of angiogenesis in vivo. Furthermore, it should now be possible to investigate scFv(L19) for the selective delivery of 211At to the tumour neovasculature, causing the selective death of tumour endothelial cells and tumour collapse.

The antibody-based targeted delivery of TNF in combination with doxorubicin eradicates sarcomas in mice and confers protective immunity

Background:

Soft-tissue sarcomas are a group of malignancies of mesenchymal origin, which typically have a dismal prognosis if they reach the metastatic stage. The observation of rare spontaneous remissions in patients suffering from concomitant bacterial infections had triggered the clinical investigation of the use of heat-killed bacteria as therapeutic agents (Coley's toxin), which induced complete responses in patients in the pre-chemotherapy era and is now known to mediate substantial elevations in serum TNF levels.

Methods:

We designed and developed a novel immunocytokine based on murine TNF sequentially fused to the antibody fragment F8 (specific to extra-domain A of fibronectin). The antitumor activity was studied in two syngeneic murine sarcoma models.

Results:

The L19 antibody (specific to extra-domain B of fibronectin) has shown by SPECT imaging procedures to selectively localise on sarcoma in a patient with a peripheral nerve sheath tumour, and immunohistochemical analysis of human soft-tissue sarcoma samples showed comparable antigen expression of EDA and EDB. The antibody-based pharmacodelivery of TNF by the fusion protein ‘F8–TNF' to oncofetal fibronectin in sarcoma-bearing mice leads to complete and long-lasting tumour eradications when administered in combination with doxorubicin, the first-line drug for the treatment of sarcomas in humans. Doxorubicin alone did not display any therapeutic effect in both tested models of this study. The cured mice had acquired protective immunity against the tumour, as they rejected subsequent challenges with sarcoma cells.

Conclusion:

The findings of this study provide a rationale for the clinical study of the fully human immunocytokine L19-TNF in combination with doxorubicin in patients with soft-tissue sarcoma.

Liver autotransplantation for the treatment of unresectable hepatic metastasis: an uncommon indication-a case report

Ex situ ex vivo liver surgery represents a method to expand the surgical indications to treat otherwise unresectable liver tumors. We report the case of a 38-year old woman with hepatic metastasis from a pancreatoblastoma that was judged to be unresectable due to the involvement of the three hepatic veins. To treat the primary tumor, she underwent a pancreaticoduodenectomy, adjuvant chemotherapy, and thermal ablation of a liver metastasis. After appropriate preoperative study and with the permission of the ethics committee, she underwent ex situ ex vivo liver resection. The hepatectomy was performed by removing the whole liver en bloc with the retrohepatic vena cava. The inferior vena cava was reconstructed by interposition of a prosthetic graft. The ex situ ex vivo hepatic resection, a left hepatic lobectomy included the lesion in segments 1-5-7-8. The two hepatic veins were reconstructed using patches of saphenous vein. The organ was preserved continuously for 6 hours using hypothermic perfusion with 4°C Celsior solution. The liver was then reimplanted performing an anastomosis between the reconstructed hepatic veins and the caval prostheses. The patient was discharged at postoperative day 22 and is currently disease-free at 8 months after surgery and 44 months after the initial diagnosis. Ex situ, ex vivo liver surgery offers an additional option for patients with both primary and secondary liver tumors considered to be unresectable using traditional surgical approaches.

Dipeptidylpeptidase--IV, a key enzyme for the degradation of incretins and neuropeptides: activity and expression in the liver of lean and obese rats

Given the scarcity of donors, moderately fatty livers (FLs) are currently being considered as possible grafts for orthotopic liver transplantation (OLT), notwithstanding their poor tolerance to conventional cold preservation. The behaviour of parenchymal and sinusoidal liver cells during transplantation is being studied worldwide. Much less attention has been paid to the biliary tree, although this is considered the Achille's heel even of normal liver transplantation. To evaluate the response of the biliary compartment of FLs to the various phases of OLT reliable markers are necessary. Previously we demonstrated that Alkaline Phosphatase was scarcely active in bile canaliculi of FLs and thus ruled it out as a marker. As an alternative, dipeptidylpeptidase-IV (DPP-IV), was investigated. This ecto-peptidase plays an important role in glucose metabolism, rapidly inactivating insulin secreting hormones (incretins) that are important regulators of glucose metabolism. DPP-IV inhibitors are indeed used to treat Type II diabetes. Neuropeptides regulating bile transport and composition are further important substrates of DPP-IV in the enterohepatic axis. DPP-IV activity was investigated with an azo-coupling method in the liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. Protein expression was studied by immunofluorescence with the monoclonal antibody (clone 5E8). In Wistar rat liver, DPP-IV activity and expression were high in the whole biliary tree, and moderate in sinusoid endothelial cells, in agreement with the literature. Main substrates of DPP-IV in hepatocytes and cholangiocytes could be incretins GLP-1 and GIP, and neuropeptides such as vasoactive intestinal peptide (VIP) and substance P, suggesting that these substances are inactivated or modified through the biliary route. In lean Zucker rat liver the enzyme reaction and protein expression patterns were similar to those of Wistar rat. In obese rat liver the patterns of DPP-IV activity and expression in hepatocytes reflected the morphological alterations induced by steatosis as lipid-rich hepatocytes had scarce activity, located either in deformed bile canaliculi or in the sinusoidal and lateral domains of the plasma membrane. These findings suggest that bile canaliculi in steatotic cells have an impaired capacity to inactivate incretins and neuropeptides. Incretin and/or neuropeptide deregulation is indeed thought to play important roles in obesity and insulin-resistance. No alteration in enzyme activity and expression was found in the upper segments of the biliary tree of obese respect to lean Zucker and Wistar rats. In conclusion, this research demonstrates that DPP-IV is a promising in situ marker of biliary functionality not only of normal but also of fatty rats. The approach, initially devised to investigate the behaviour of the liver during the various phases of transplantation, appears to have a much higher potentiality as it could be further exploited to investigate any pathological or stressful conditions involving the biliary tract (i.e., metabolic syndrome and cholestasis) and the response of the biliary tract to therapy and/or to surgery.

B domain containing Tenascin-C: a new urine marker for surveillance of patients with urothelial carcinoma of the urinary bladder?

BACKGROUND

ECM remodelling during tumorigenesis entails the re-occurrence of different Tn-C(L) splicing variants. In patients with urothelial carcinoma of the urinary bladder (UBC), B and C domain containing Tenascin-C (B(+) and C(+) Tn-C) urine levels were shown to be increased in case of muscle invasiveness. Thus, the present study was aimed at examining the ability of B(+) and C(+) Tn-C as potential urinary surveillance markers of UBC patients.

METHODS

Urine levels of B(+) and C(+) Tn-C were determined by ELISA in 35 UBC patients during a 2 year follow-up period after therapy and related to clinical diagnosis and histological stage in 4 defined groups representing typical courses of disease.

RESULTS

B(+) Tn-C levels showed significant differences between cases of tumour progression or regression. The urine levels of B(+) Tn-C could be used to discriminate between cases without tumour recurrence and such with tumour existence (cut-off value: 0.8 ng/ml) or between non-muscle invasive and muscle invasive tumour growth (cut-off value: 3.5 ng/ml).

CONCLUSIONS

Progression of UBC with time is accompanied by significant changes in urinary levels of B(+) Tn-C. Urinary B(+) Tn-C can therefore be suggested as a valuable urine surveillance marker in UBC follow-up care.