Abstract 2994: In vivo targeting of mesothelioma’s molecular signature with nanoparticle functionalized with nucleolin-binding peptide

Mesothelioma is a malignant tumor of the mesothelium, often associated with asbestos exposure, with an overall survival of only 8.8 months. A combination of cisplatin and pemetrexed has been used as an adjuvant treatment to surgical resection or in patients who have inoperable disease. This combination remains as the current standard of care, regardless the sub-type of mesothelioma, with only a 9% 5-year survival rate. Herein, it is hypothesized that a novel targeted treatment, based on a doxorubicin (DXR)-containing nanoparticle functionalized with the nucleolin-binding F3 peptide (named PEGASEMP), will have significant a therapeutic impact against the most aggressive subtype of mesothelioma (biphasic). The hypothesis relies on nucleolin deregulated overexpression in cancer and endothelial cells from tumor blood vessels. Human biphasic mesothelioma cells were stably transduced with luciferase-reporter gene, and orthotopically injected intrapleurally into female immunocompromised mice. Three weeks (Early Stage) and 4 weeks (Advanced Stage) after cell injection, animals were randomly allocated to different treatment groups: vehicle, PEGASEMP at 5.6 or 7 mg of DXR/kg alone (q7dx5w); cisplatin at 4.0 mg/kg alone or combined with PEGASEMP at 5.6 mg of DXR/kg (q7dx5w); and the standard of care, a combination of cisplatin at 4.0 mg/kg (q7dx5w) plus pemetrexed at 100.0 mg/kg (q2dx3x5w). Bioluminescence was monitored weekly with IVIS Spectrum In Vivo Imaging system. Differential gene expression upon PEGASEMP treatment of advanced stage tumors was also performed in comparison with non-treated animals using the GeneChip Human Transcriptome Array 2.0. In the early stage of development, PEGASEMP, at 7.0 mg/kg, inhibited tumor growth by 2,713-fold relative to standard of care, which translated into a 1223-fold decrease in tumor burden. At an advanced stage of tumor development, the combination of PEGASEMP and cisplatin enabled 107-fold tumor growth inhibition, enabling a 55-fold reduction in tumor burden, relative to standard of care. In both cases, no decrease of the body weight was observed. Furthermore, 75% (146) gene transcripts were found to be deregulated (while the remaining 25% were upregulated), involving the downregulation of cell division, including ontologies such as cell cycle or chromatin organization and assembly. Specifically, downregulation of topoisomerase 2, cyclin B1 or Ki67 transcripts, part of the described molecular signature of mesothelioma, was observed and was consistent with the mechanism of action of doxorubicin. Overall, the novel mechanism of action associated with PEGASEMP, enables a significant benefit in terms of efficacy and safety in the treatment of biphasic mesothelioma, as compared with the current standard of care, affecting the molecular signature of the disease and thus supporting future clinical evaluation.

Citation Format: Nuno A. Fonseca, Vera Moura, Fabiana Colelli, Daniela Pesce, Giacomo Signorino, Laura Focareta, Alessandra Fucci, Francesco Cardile, Claudio Pisano, Sérgio Simões, João Nuno Moreira. In vivo targeting of mesothelioma’s molecular signature with nanoparticle functionalized with nucleolin-binding peptide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2994.

Abstract 5155: Targeting nucleolin with doxorubicin-containing nanoparticle induces a significant tumor growth inhibition in an orthotopic animal model of standard of care-resistant mesothelioma

Mesothelioma is a malignant tumor of the mesothelium, the thin lining of the surface of the body cavities and the organs within, and is often associated with asbestos exposure. It has a poor prognosis, with a mean overall survival of 8.8 months. Chemotherapy has been used for malignant pleural mesothelioma as an adjuvant treatment after surgical resection (often palliative) or in patients who have inoperable disease. A combination of cisplatin and pemetrexed remains as the current standard of care, with only a 9% 5-year survival rate. Herein, a novel targeted treatment for mesothelioma, based on a doxorubicin (DXR)-containing nanoparticle functionalized with the nucleolin-binding F3 peptide (named PEGASEMP), is proposed. It relies on nucleolin deregulated overexpression in cancer cells and the tumor microenvironment (endothelial cells from tumor blood vessels). Studies were performed in an orthotopic model of human mesothelioma. Mesothelioma cells harvested from a patient with disease progression who undergone chemotherapy, were stably transduced with luciferase-reporter gene, and orthotopically injected intrapleurally into female immunocompromised mice. Animals were randomly allocated to different treatment groups: vehicle, peptide-targeted DXR-containing nanoparticle (PEGASEMP) at 5.6 or 7 mg of DXR/kg alone (q7dx5w); cisplatin at 4.0 mg/kg alone or combined with PEGASEMP at 5.6 mg of DXR/kg (q7dx5w). A control group administered with the standard of care, a combination of cisplatin at 4.0 mg/kg (q7dx5w) plus pemetrexed at 100.0 mg/kg (q2dx3x5w) was also included. Bioluminescence was monitored weekly with live imaging using IVIS Spectrum In Vivo Imaging system. Peptide-targeted DXR-containing nanoparticle at 7.0 mg/kg enabled a tumor growth inhibition, by the end of the treatment, that was 183-fold higher than the standard of care. Moreover, treatment with DXR-containing nanoparticle targeting nucleolin, either at 5.6 or 7.0 mg/kg, enabled a 10- or 66-fold reduction of tumor burden, respectively, relative to non-treated mice. Conversely, treatment with the standard of care did not show any effect on tumor growth inhibition (being similar to the group injected with vehicle) nor on tumor burden. Importantly, DXR-containing nanoparticle targeting nucleolin, at the highest tested dose, enabled a marked decreased of the incidence of tumor infiltration into the chest cavity, as well as of the presence of severe lung lesions, as compared with the standard of care (57.1% versus 100% and 14.3% versus 50%, respectively). Overall, the novel mechanism of action associated with DXR-containing nanoparticle targeting nucleolin, enables a significant benefit in terms of efficacy (and safety) in the treatment of mesothelioma, as compared with the current standard of care, thus supporting future clinical evaluation.

Citation Format: Nuno André Fonseca, Vera Moura, Fabiana Colelli, Daniela Pesce, Francesco Cardile, Claudio Pisano, Sérgio Simões, João Nuno Moreira. Targeting nucleolin with doxorubicin-containing nanoparticle induces a significant tumor growth inhibition in an orthotopic animal model of standard of care-resistant mesothelioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5155. doi:10.1158/1538-7445.AM2017-5155

Preclinical pharmacology and safety of a novel avidin derivative for tissue-targeted delivery of radiolabelled biotin

We recently described an oxidized avidin variant, named AvidinOX(®) , which is a product that chemically links to tissue proteins while maintaining the capacity to uptake intravenously administered biotin. Such product proved to be successful in targeting radionuclide therapy in a mouse model of inoperable breast cancer. Here, we show that the uptake of a single or multiple doses of biotin (up to five times), by the tissue-bound AvidinOX(®) , is stable for 2 weeks. Taking into account that oxidized avidin is the first chemically reactive protein to be proposed for clinical use, we evaluated its tolerability, immunogenicity and mutagenicity. Present in vitro data indicate that AvidinOX(®) (up to 10 μg/5 × 10(5) cells) does not affect cell viability or proliferation of PC3 human prostate cancer or 3T3 mouse fibroblast cell lines as well as primary mouse spleen cells. Safety pharmacology and toxicology studies were conducted using AvidinOX(®) up to the highest concentration compatible with its solubility (about 12 mg/mL), representing four times the product concentration intended for human use, and in the maximum administrable volume compatible with each study system. The intramuscular administration in rat and monkey induced a moderate to strong inflammatory response particularly after a second administration and consistently with the induction of an immune response. Interestingly, the intramuscular administration of AvidinOX(®) to rodents and monkeys exhibiting very high anti-avidin antibody titres was well tolerated with no systemic symptoms of any kind. Intravenous administration of AvidinOX(®) , performed to mimic an accidental injection of the dose intended for a local administration (15 μL of 3.3 mg/mL solution), showed significant localization of the product into the spleen not associated with uptake of the radiolabelled biotin intravenously injected after 24 hr, thus suggesting rapid inactivation. No mutagenic activity was induced by oxidized avidin in prokaryotic and eukaryotic cells. Overall, the present data indicate that AvidinOX(®) is well tolerated in rodents and non-human primates, thus supporting its clinical use within protocols of radionuclide therapy of inoperable tumour lesions.

Propionyl-L-carnitine reduces intimal hyperplasia after injury in normocholesterolemic rabbit carotid artery by modulating proliferation and caspase 3-dependent apoptosis of vascular smooth muscle cells

Previously we documented that propionyl-L-carnitine (PLC) reduces the growth of atherosclerotic lesions in cholesterol-fed aged rabbits in association with a decrease of plaque smooth muscle cell (SMC) proliferation and plasma triglycerides. To clarify whether PLC might influence SMC growth through mechanisms other than triglyceride lowering, we investigated the effect of a daily treatment per os with PLC on carotid intimal hyperplasia after ballooning in normocholesterolemic rabbits. PLC did not induce variations of plasma triglyceride and cholesterol. One week later, the number of proliferating SMCs was reduced in PLC as compared with controls. After 3 weeks, morphometric analysis demonstrated a reduced neointimal relative volume and percentage of stenosis but not vessel area in PLC as compared with controls. This associated with an intimal reduced SMC number and an increased apoptotic rate as detected by nick-end labelling (TUNEL) and ligation-mediated polymerase chain reaction (PCR). Western blotting also demonstrated an increase of caspase-3 cleavage in PLC carotids. Antiproliferative and pro-apoptotic effects of PLC were confirmed in vitro on actively proliferating and serum deprived SMCs, respectively. Molecules with an additional cell-specific, pro-apoptotic action may represent a new therapeutic tool in reducing intimal SMC hyperplasia following angioplasty or stenting procedures.

Periodontal tissue disposition of azithromycin in patients affected by chronic inflammatory periodontal diseases

BACKGROUND

The recognition that periodontal diseases are associated with specific pathogens has led to interest in the use of antibacterial drugs for inhibition of these microorganisms. On these bases, the present study was aimed at evaluating the tissue distribution of the new macrolide antibiotic azithromycin in patients subjected to oral surgery for chronic inflammatory diseases of both marginal and periapical periodontium.

METHODS

Thirty-two patients were treated with azithromycin 500 mg/day orally for 3 consecutive days, and drug concentrations in plasma, saliva, normal gingiva, and pathological periodontal tissues were evaluated. For this purpose, samples of blood, saliva, normal gingiva, granulation tissue, and radicular granuloma or cyst wall (from dentigerous cyst) were collected during oral surgery or 0.5, 2.5, 4.5, and 6.5 days after the end of pharmacological treatment; then, azithromycin levels were measured by a microbiological plate assay, using Micrococcus luteus NCTC 8440 as the indicator organism.

RESULTS

The concentrations of azithromycin in plasma, saliva, normal gingiva, and pathological tissues reached the highest values 12 hours after the last dose (0.37+/-0.05 mg/l, 2.12+/-0.30 mg/l, 6.30+/-0.68 mg/kg, and 11.60+/-1.50 mg/kg, respectively) and then declined gradually. Consistent levels of the drug in normal gingiva and pathological tissues could be detected, however, up to 6.5 days, indicating that azithromycin was retained in target tissues for a long time after the end of treatment. Moreover, azithromycin levels in both normal gingiva and pathological tissues exceeded the minimum inhibitory concentrations of most pathogens involved in the pathophysiology of chronic inflammatory periodontal diseases. Notably, azithromycin levels in pathological tissues were significantly higher than those in normal gingiva 0.5, 2.5, and 4.5 days after the last dose.

CONCLUSIONS

The present results indicate a marked penetration of azithromycin into both normal and pathological periodontal tissues, suggesting that azithromycin represents a promising option in both adjunctive and prophylactic treatments of chronic inflammatory periodontal diseases.

[Use of minitracheotomy in high-risk pulmonary resection surgery. Results of a comparative study]

Twenty patients undergoing lung resections were randomized into two groups: group 1 (n = 10) received mini-tracheotomy postoperatively and group 2 (n = 10) were control patients. The two groups were similarly matched in pulmonary functions (FEV1 < 1.8 1), performance status and surgical procedures (major pulmonary resections). All patients were monitored by serial chest X-ray examinations, arterial blood gases, clinical assessment and response to chest physiotherapy. Postoperative pulmonary complications of atelectasis/bronchopneumonia developed in 1 patient in group A and 4 patients in group B. Two patients of this last group required mini-tracheotomy to treat the pneumonia. The mean overall duration of mini-tracheotomy was 6.3 days. Five patients presented minor temporary symptoms related to mini-tracheotomy, including voice changes, discomfort and stridor. No long term morbidity was observed. We concluded that the use of mini-tracheotomy is safe and effective in decreasing postoperative respiratory morbidity in high risk patients.

Effect of propionyl-L-carnitine in a rat model of peripheral arteriopathy: a functional, histologic, and NMR spectroscopic study

Propionyl-L-carnitine (PLC) has been shown to exert beneficial effects in experimental models of peripheral arterial diseases, such as ergotamine-induced tail gangrene and bilateral femoral arteries occlusion in rats. These models, however, present some drawbacks. The present study was performed to determine whether repeated oral administration of PLC improves the functional, histologic, and metabolic parameters in rats with long-lasting chemically induced peripheral arteriopathy. Peripheral arteriopathy was induced by injecting Na laurate in both the femoral arteries of rats. The walking capacity of the animals (treadmill test) was evaluated at different times and up to 5 weeks after Na laurate injection. Histological examination of vessels and muscles was performed at the end of the experimental period (5 weeks). In separate experiments the level of high-energy phosphates was determined with 31P NMR methodology in the leg muscles. Injection of Na laurate impaired (p < 0.05) the walking capacity of rats, caused thickening of the intima and marked narrowing of the vasal lumen, and reduced the ATP and PCr levels in muscles by 42% and 25%, respectively. PLC given orally for 7 days at 30, 60, 120, and 250 mg/kg dose-dependently decreased the severity of walking capacity impairment by 19%, 41%, 64%, and 71%, respectively. Long-term administration (4 weeks) of PLC (60 and 250 mg/kg os) caused a significant improvement of walking capacity throughout the entire period. The improvement persisted 1 week after discontinuation of the treatment. The severity of the vascular and muscular damages was markedly reduced, particularly in animals treated with the highest dose. Alterations in ATP and PCr levels were significantly (p < 0.05) diminished by PLC (120 mg/kg os) administered daily for 15 days starting 24 hours after Na laurate injection, or for 11 days starting 4 days after Na laurate. The dextro-isomer of the compound was completely inactive, and L-carnitine improved motor performance to a much lesser degree than an identical dose of PLC. It is suggested that the activity of PLC is linked to its metabolic effects on fatty acid oxidation, with consequent preservation of high-energy phosphate levels.