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X-ray photodynamic therapy (XPDT) has been recently considered as an efficient alternative to conventional radiotherapy of malignant tissues. Nanocomposites for XPDT typically consist of two components—a nanophosphor which re-emits X-rays into visible light that in turn is absorbed by the second component, a photosensitizer, for further generation of reactive oxygen species. In this study, BaGdF5 nanophosphors doped with different Eu:Gd ratios in the range from 0.01 to 0.50 were synthesized by the microwave route. According to transmission electron microscopy (TEM), the average size of nanophosphors was ~12 nm. Furthermore, different coatings with amorphous SiO2 and citrates were systematically studied. Micro-CT imaging demonstrated superior X-ray attenuation and sufficient contrast in the liver and the spleen after intravenous injection of citric acid-coated nanoparticles. In case of the SiO2 surface, post-treatment core–shell morphology was verified via TEM and the possibility of tunable shell size was reported. Nitrogen adsorption/desorption analysis revealed mesoporous SiO2 formation characterized by the slit-shaped type of pores that should be accessible for methylene blue photosensitizer molecules. It was shown that SiO2 coating subsequently facilitates methylene blue conjugation and results in the formation of the BaGdF5: 10% Eu3+@SiO2@MB nanocomposite as a promising candidate for application in XPDT.

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Herein we report the development of a nanocomposite for X-ray-induced photodynamic therapy (X-PDT) and computed tomography (CT) based on PEG-capped GdF3:Tb3+ scintillating nanoparticles conjugated with Rose Bengal photosensitizer via electrostatic interactions. Scintillating GdF3:Tb3+ nanoparticles were synthesized by a facile and cost-effective wet chemical precipitation method. All synthesized nanoparticles had an elongated “spindle-like” clustered morphology with an orthorhombic structure. The structure, particle size, and morphology were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analysis. The presence of a polyethylene glycol (PEG) coating and Rose Bengal conjugates was proved by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and ultraviolet–visible (UV-vis) analysis. Upon X-ray irradiation of the colloidal PEG-capped GdF3:Tb3+–Rose Bengal nanocomposite solution, an efficient fluorescent resonant energy transfer between scintillating nanoparticles and Rose Bengal was detected. The biodistribution of the synthesized nanoparticles in mice after intravenous administration was studied by in vivo CT imaging.

e15033 Background: Cardioesophageal cancer is a common tumor affecting the cardiac stomach and lower esophagus. Tumor heterogeneity is important, since it can cause the ineffectiveness of chemotherapy and radiotherapy due to individual characteristics of the neoplasm in different patients, as well as the intensification of invasion and metastasis. Our purpose was to analyze the relative copy numbers of TP63, YAP1 and KMT2D genetic loci and EGFR expression in orthotopic patient-derived xenografts of cardioesophageal cancer. Methods: The model of cardioesophageal cancer was created in Balb/c Nude mice with surgical bioptates of adenocarcinoma obtained from donors. The relative copy numbers of TP63, YAP1 and KMT2D genetic loci and EGFR expression were determined by Real-Time qPCR. Results: A PDX model of cardioesophageal cancer was successfully created by transplanting a moderately differentiated adenocarcinoma from a patient diagnosed with infiltrative ulcerative cancer of the lower third of the esophagus with a transition to the cardiac stomach into the distal esophagus of Balb/c Nude mice. The EGFR expression was elevated in patient tumor samples, compared to healthy tissues (p = 0.021) and gastric cancer xenografts (p = 0.07). Molecular genetic analysis demonstrated an association between an increased EGFR expression and changes in the relative copy numbers of TP63, YAP1, and KMT2D in donor samples compared to gastric cancer xenografts (p = 0.02, p = 0.026 and p = 0.042). Conclusions: The relative copy numbers of TP63, YAP1, and KMT2D were associated with intensified EGFR expression and changed with each new generation of orthotopic xenografts.

e15034 Background: Cardioesophageal cancer is one of the most common tumors affecting the mucosa of the cardiac stomach and distal esophagus. Despite the variety of treatment strategies and chemotherapy agents, the prognosis for the patients remains poor. The purpose of the study was to analyze the relative copy numbers of SOX-2 and NOTCH1 and vimentin expression in orthotopic patient-derived xenografts of cardioesophageal cancer. Methods: The model of cardioesophageal cancer was created in Balb/c Nude mice with surgical bioptates of moderately differentiated adenocarcinoma obtained from a donor with infiltrative ulcerative cancer of the lower third of the esophagus with a transition to the cardiac stomach into the distal esophagus of Balb/c Nude mice. The index of proliferative activity in the bioptates was assessed by IHC. The relative copy numbers of SOX-2 and NOTCH1 and vimentin expression were determined by Real-Time qPCR. Results: Expression of vimentin was absent in tissues of the donor tumor. The levels of vimentin expression statistically significantly increased in xenografts (1+ and 3+). The SOX-2 and NOTCH1 relative copy numbers were statistically significantly increased in tissues of the donor tumor (0.9 and 0.7), compared to xenografts (1.5±0.03 and 1.7±0.03). Molecular genetic analysis demonstrated an association between an increased vimentin expression and changes in the relative copy numbers of SOX-2 and NOTCH1 (p = 0.013 and p = 0.0001). Conclusions: The relative copy numbers of SOX-2 and NOTCH1 genetic loci was associated with increased expression of the epithelial-mesenchymal transition marker vimentin in tumor tissue samples and changed with each new generation of orthotopic xenografts.

The aim. To study the toxicity of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in vitro and in vivo.Materials and methods. 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone was synthesized using a method for expanding the o-quinone cycle during the reaction between 5-nitro-2,6,8-trimethyl4-chloroquinoline and 3,4,5,6-tetrachloro-1,2-benzoquinone while boiled in dioxane. An in vitro experiment was carried out in the human A549 cell line. Cell viability was assessed using the MTT colorimetric assay by reducing the optical density of the experimental samples compared with the control ones. Acute toxicity was studied on 20 BALB/c Nude male mice. The test compound was administered once orally as a suspension in 1% starch gel at three doses: 0.0055 (group 1), 0.055 (group 2) and 0.55 mg / g (group 3). The control group (group 4) received a placebo.Results. We synthesized a new compound, 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone. Its structure was established by 1 H nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and mass spectrometry. The yield was 19.8 g (52%), the melting point was 205–207 ºС, bright yellow crystals (benzene) were observed. The half-maximal inhibitory concentration (IC50) of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone was 0.21 ± 0.01 μM, which was significantly lower (р < 0.05) than the IC50 of cisplatin (3.84 ± 0.23). Following the in vivo experiment, no toxic effect of tropolone was detected when administered once at a dose of 0.0055, 0.055, and 0.55 mg / g. Conclusion. 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone demonstrated cytotoxic effects on the A549 cell line at a lower IC50 than cisplatin which is widely used in treatment of cancers, including lung cancer. Insolubility of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in water and the absence of its toxic effect in the studied modes determine the scope of its application for further study of cumulative and antitumor effects.

Purpose of the study. Was to analyze antitumor efficacy of the XAV 939 Wnt signaling pathway inhibitor and its combination with 5 fluorouracil in subcutaneous xenografts derived from patients with colorectal cancer.Materials and methods. Antitumor efficacy of the agents and their combination was studied in xenografts derived from patients with colorectal cancer and subcutaneously implanted in immunodeficient Balb/c Nude mice. All animals with tumors were divided into 4 groups (n = 5): group 1 received 5 fluorouracil 25 mg/kg, group 2 – XAV 939 25 mg/kg, group 3–5 fluorouracil and XAV 939 combination at the same dosages, group 4 was control. Criteria for the efficacy of the tested agents and their combination included tumor growth rate and tumor growth inhibition rate (TGI %).Results. The mean volumes of xenografts and tumor growth rate in the group receiving a combination of 5 fluorouracil and XAV 939 were 335.2 ± 40.7 mm3 , being lower than the averages of xenografts in controls – 609.3 ± 69.5 mm3 (p < 0.05). The mean volumes of xenografts in the group receiving 5 fluorouracil monotherapy were 601.9 ± 45.5 mm3 , in the group with the XAV 939 monotherapy – 527.9 ± 258.6 mm3 . The highest TGI (44.99 %) was registered in the group receiving a combination of 5 fluorouracil and XAV 939.Conclusion. The study revealed the ability of combined XAV 939 Wnt signaling pathway inhibitor and 5 fluorouracil to inhibit the growth of subcutaneous xenografts derived from patients with colorectal cancer.