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A series of new fist-time synthesized of thiazolyl-substituted 4-aminopyrimidine was obtained on the basis of a two-stage process including thioamidation of 4-amino-5-cyanopyrimide followed by one-pot acylation and Hantzsch synthesis in good yield (52–77%). All synthesized compounds showed a good anticancer effect in antiproliferative assay (end point) on three tumor lines A431, A549 и HT-1080

Objective The problem of drug resistance to BRAF-targeted therapy often occurs in melanoma treatment. Activation of PI3K/AKT/mTOR signaling pathway is one of the mechanisms of acquired resistance and a potential target for treatment. In the current research, we investigated that dual inhibition of mTOR and MEK synergistically reduced the viability of melanoma cells in vitro. Methods A combination of rapamycin (a macrolide immunosuppressant, mTOR inhibitor) and binimetinib (an anti-cancer small molecule, selective inhibitor of MEK) was studied using a panel of melanoma cell lines, including patient-derived cells. Results It was found, that combinatorial therapy of rapamycin (250 nM) and binimetinib (2 μM) resulted in 25% of cell viability compared to either rapamycin (85%) or binimetinib alone (50%) for A375 and vemurafenib-resistant Mel IL/R cells. The suppressed activation of mTOR and MEK by combined rapamycin and binimetinib treatment was confirmed using Western blot assay. Cell death occured via the apoptosis pathway; however, the combination treatment significantly increased the apoptosis only for Mel IL/R cells. The enhanced cytotoxic effect was also associated with enhanced cell cycle arrest in the G0/G1 phase. Conclusion In general, we provide the evidence that dual inhibition of mTOR and MEK could be promising for further preclinical investigations.

Abstract Upconversion nanoparticles (UCNPs) are a promising nanoplatform for bioreagent formation for in vivo imaging, which emit UV and blue light under the action of near-infrared radiation, providing deep tissue penetration and maintaining a high signal-to-noise ratio. In the case of solid tumor visualization, the UCNP surface functionalization is required to ensure a long circulation time, biocompatibility, and non-toxicity. The effective UCNP accumulation in the solid tumors is determined by the disturbed architecture of the vascular network and lymphatic drainage. This work demonstrates an approach to the UCNP biofunctionalization with endogenous polysialic acid for in vivo bioreagent formation. Bioreagents possess a low level of nonspecific protein adsorption and macrophage uptake, which allow the prolongation of the circulation time in the bloodstream up to 3 h. This leads to an intense photoluminescent signal in the tumor.

Introduction.The molecular basis of radio- and photodynamic therapy (PDT), the mechanism of action of a number of antitumor chemotherapy drugs is oxidative stress (OS). The enzyme hemoxygenase-I (НO-1), a molecular marker of OS, is a key participant in the system of protection and adaptation of tumor cells under stress.Objective.To find out whether the sensitivity of human melanoma tumor cells to OS depends on the basal and modulator-induced levels of НO-1 expressionMaterial and methods.Human melanoma cell lines were used in the study. The expression of mRNA НO-1 in cells was studied by real-time RT-PCR, the reactive oxygen species content in cells – by flow cytometry and the cytotoxicity of drugs – by MTT assay.Results.According to our data, human melanoma cells have different basal levels of HO-1 transcription: high (3.0–3.5 o. u.) in lines MelIL, MelP, medium (1.5 o. u.) in lines MeWo, MelZ, MelIbr and low (0.5 o. e.) – MelMe, A375).There is no direct correlation between the level of basal cell expression of HO-1 and their sensitivity to the OS inducer – Н2О2. The hemin-induced increase in HO-1 expression in cells is accompanied by doubled resistance to Н2О2. It was found that HO-1 repression in the presence of apigenin was registered in melanoma cells with different basal levels, but sensitization to Н2О2 (2–4 times) was observed only for cells with medium (MeWo) and low (A375) levels of basal HO-1 expression. It was found that the decrease in basal expression of HO-1 induced by apigenin is accompanied by an increase in the reactive oxygen species content in cells.Conclusions.The results of our research allow us to recommend natural flavon apigenin, a modulator of HO-1 expression, for inclusion in the chemotherapy and PDT regimens to increase the effectiveness of human melanoma treatment.

Objective: to assess the expression and prognostic value of vascular endothelial growth factor A (VEGF-A), fibroblast growth factor 2 (FGF-2) and their receptors VEGFR-1, -2; FGFR-1, -2, as well as platelet-derived growth factor receptors (PDGFR-α, PDGFR-β) in paired samples of primary tumors and tumor thrombi in renal cell carcinoma (RCC).Materials and methods. Expression of VEGF-A, FGF-2, VEGFR-1, -2; FGFR-1, -2; PDGFR-α, -β was studied in paired surgical samples of primary tumors and tumor thrombi in 25 patients with clear cell RCC pT3a–T4N0–1M0–1 and tumor venous thrombosis by immunohistochemical assay using the appropriate Abcam/Santa Cruz Biotech antibodies from the immunohistochemical staining kit Invitrogen. Expression levels were evaluated by a semi-quantitative method (H-score). The analysis of the correlation between expression levels of VEGF-A, FGF-2, VEGFR-1, -2; FGFR-1, -2; PDGFR-α, -β and RCC characteristics, as well as evaluation of their influence on the outcome of RCC were performed.Results. VEGF-A, FGF-2, as well as VEGFR-1, -2; FGFR-1, -2; PDGFR-α, -β were expressed in the cytoplasm and on the membrane of the primary tumor and tumor thrombus cells in RCC patients. Tumor thrombus cells were characterized by lower expression of VEGFR-1, VEGFR-2, PDGFR-α (p ³2 identified risk factors was 27.3 %, risk factors – 87.5 % (p = 0.004).Conclusion. Tumor thrombus cells in RCC patients expressed VEGF-A, FGF-2, VEGFR-1, -2; FGFR-1, -2; PDGFR-α, -β less active than the cells of the primary tumor. Overexpression of growth factors and tyrosine kinases correlated with RCC Furman grade and tumor venous wall invasion. Overexpression of VEGFR-2 in both primary tumor and thrombus cells in combination with hypoexpression of VEGF-A in the thrombus negatively influenced on OS.

The research is devoted to comparison of the blood vessel structure and the oxygen state of three xenografts: SN-12C, HCT-116 and Colo320. Differences in the vessel formation and the level of oxygenation are revealed by optoacoustic (OA) microscopy and diffuse optical spectroscopy (DOS) respectively. The Colo320 tumor is characterized by the highest values of vessel size and fraction. DOS showed increased content of deoxyhemoglobin that led to reduction of saturation level for Colo320 as compared to other tumors. Immunohistochemical (IHC) analysis for CD31 demonstrates the higher number of vessels in Colo320. The IHC for hypoxia was consistent with DOS results and revealed higher values of the relative hypoxic fraction in Colo320.

Novel 4-amino-5-cyano-2-sulfonylpyrimidines were prepared based on three-component cyclization between isothiouronium salts, benzaldehydes and malononitrile, followed by oxidation of the sulfide moiety with Oxone. The cytotoxic activity of the synthesized compounds, as well as the induction of apoptosis, inhibition of the cell cycle and proliferation tests were performed on selected cancer cell lines A431, A549, A375, HCT 116, MCF7, LNCap and SH-SY5Y.

The possibilities of using fluorescence-based analytical methods and their advantages for visualization and identification of the type of programmed cell death in human tumor cells exposed to flavonoids have been analyzed in experiments in vitro. HeLa cervical cancer cells and A498 kidney carcinoma cells were used as the objects of the study, and exposure to the flavonoid-containing extract of common hedgehyssop (Gratiola officinalis L.) was tested as the experimental treatment. The following fluorescence-based techniques were used: the “live and dead” test with double staining by propidium iodide and acridine orange and double staining with annexin and propidium iodide. Autophagy induction was confirmed by fluorescence-based tests implemented in a Muse cell analyzer with a Muse Autophagy LC3-Antibody Based Kit. The use of double staining with acridine orange and propidium iodide fluorescent dyes in the “live and dead” test and comparison with phase contrast microscopy enables the visualization of apoptotic body and autophagosome formation processes in the cells and can, therefore, be used as a method of screening assessment of the efficiency of various chemotherapy drugs.

1-Imidoylbenzotriazoles [N-aryl-1-(1H-benzotriazol-1-yl)-2,2,2-trifluoroethan-1-imines] reacted with tosylmethyl isocyanide according to van Leusen’s procedure to give difficultly accessible 1-aryl-4-(4-methylbenzenesulfonyl)-5-(trifluoromethyl)-1H-imidazoles in good yields (81–94%). The initial imidoylbenzotriazoles were conveniently synthesized by reaction of sodium benzotriazolide with the corresponding imidoyl chlorides in THF. The reactions were carried out with a wide series of imidoylbenzotriazoles containing various electron-donating and electron-withdrawing substituents in the N-aryl fragment.

Lanthanide-doped upconversion nanoparticles (UCNPs) are promising bioimaging agents that emit light under near infra-red excitation, capable of penetrating deep in biotissues with a high signal-to-noise ratio. Their successful implementation is principally associated with surface functionalization. Here, we report on UCNP surface modification with highly hydrophilic, endogenous, non-toxic, non-immunogenic colominic acid, conferring "stealth" properties. We proposed surface functionalization of UCNPs based on a two-step strategy, which consists of hydrophilization with polyethyleneimine and attachment of colominic acid by electrostatic or covalent bond formation. Analysis revealed that regardless of the nature of the bond, colominic acid acted as a non-cytotoxic UCNP surface coating with low nonspecific blood protein adsorption. UCNP-colominic acid nanocomplexes exhibited low uptake by macrophages in vitro, which plays an active role in inflammatory reactions. We demonstrated the superiority of colominic acid compared to polyethylene glycol coating in terms of the prolonged circulation time in the bloodstream of small animals when injected intravenously. The colominic acid coating made it possible to prolong the UCNP circulation time up to 3 h. This led to the efficient UCNP accumulation in the inflammation site due to microvascular remodeling, accompanied by an enhanced uptake and retention effect. UCNP-assisted imaging of inflammation in the whole-body mode as well as local visualization of blood vessels were acquired in vivo. These collective findings validate the functional significance of UCNP decoration with colominic acid for their application in bioimaging.

Theranostics is the direction in modern biomedicine aimed at developing drugs that combine the capabilities of diagnosis and therapy of tumors in one agent. Upconversion nanophosphors (UCNPs) are inorganic crystalline materials that can be used to create a nanoplatform providing diagnostic and therapeutic modalities. They have been proposed as luminescent markers for optical imaging of biological tissue due to their anti-Stokes luminescence, lack of photodegradation and low toxicity. In this article, UCNPs as a theranostic agent for both optical imaging and delivery of anticancer drugs have been offered. To obtain biocompatible nanocomplexes, UCNP surface with a core/shell structure of NaYF4:Yb3+Tm3+/NaYF4 was modified with polylactic acid in the presence of various stabilizers (dextran, polyvinyl alcohol, and poly-N-vinylpyrrolidone). To give the therapeutic modality to the nanocomplex, the antitumor antibiotic doxorubicin was loaded into the polymer shell. The loading efficiency was up to 0.1 mg per 1 mg UCNPs. The toxicity and the intracellular accumulation of nanocomplexes were evaluated in vitro. It was concluded that the modification of UCNPs with polylactic acid provides the transport of doxorubicin, allowing the combination of diagnostic and therapeutic modalities in one agent.

Oncolytic viruses, including live attenuated measles virus (MV) vaccine strains, have recently been shown as promising therapeutic agents against human malignancies. In this study, the oncolytic potential of the attenuated vaccine strain Leningrad-16 (L-16) of MV was evaluated in a panel of human metastatic melanoma cell lines. The L-16 measles virus was shown to replicate within melanoma cells mediating direct cell killing of tumor cells, although all melanoma cell lines varied in regard to their ability to respond to L-16 MV infection, as revealed by the different pattern of the Interferon Stimulated Gene expression, cytokine release and mechanisms of cell death. Furthermore, the statistically significant L-16 measles virus related tumor growth inhibition was demonstrated in a melanoma xenograft model. Therefore, L-16 MV represents an appealing oncolytic platform for target delivery of therapeutic genes along with other attenuated measles virus strains.

The discovery of B-RAF activating mutations in malignant melanoma cells has led to the development of a number of targeted drugs, which block exclusively the mutant B-RAF protein. Tumor cells often acquire resistance to B-RAF inhibitors via activation of alternative signaling pathways. One of the resistance mechanisms is activation of PDGF, VEGF, c-KIT, and certain other tyrosine kinases. The possibility of overcoming the resistance to the B-RAF inhibitor Vemurafenib by inactivating receptor tyrosine kinases (RTKs) was studied in metastatic melanoma cell lines differing in B-RAF mutations and RTK activity. It was found that RTK inactivation may help to overcome resistance to B-RAF inhibitors via inhibition of tyrosine kinase phosphorylation and a subsequent blocking of the PI3K-AKT-mTOR and MEK-ERK1/2 downstream signaling pathways. The changes eventually mitigated the cell growth and enhanced the Vemurafenib-dependent cell cycle arrest.

Formulation of promising anticancer herbal drug curcumin as a nanoscale-sized curcumin (nanocurcumin) improved its delivery to cells and organisms both in vitro and in vivo. We report on coupling nanocurcumin with upconversion nanoparticles (UCNPs) using Poly (lactic-co-glycolic Acid) (PLGA) to endow visualisation in the near-infrared transparency window. Nanocurcumin was prepared by solvent-antisolvent method. NaYF4:Yb,Er (UCNP1) and NaYF4:Yb,Tm (UCNP2) nanoparticles were synthesised by reverse microemulsion method and then functionalized it with PLGA to form UCNP-PLGA nanocarrier followed up by loading with the solvent-antisolvent process synthesized herbal nanocurcumin. The UCNP samples were extensively characterised with XRD, Raman, FTIR, DSC, TGA, UV-VIS-NIR spectrophotometer, Upconversion spectrofluorometer, HRSEM, EDAX and Zeta Potential analyses. UCNP1-PLGA-nanocurcumin exhibited emission at 520, 540, 660 nm and UCNP2-PLGA-nanocurmin showed emission at 480 and 800 nm spectral bands. UCNP-PLGA-nanocurcumin incubated with rat glioblastoma cells demonstrated moderate cytotoxicity, 60–80% cell viability at 0.12–0.02 mg/mL marginally suitable for therapeutic applications. The cytotoxicity of UCNPs evaluated in tumour spheroids models confirmed UCNP-PLGA-nanocurcumin therapeutic potential. As-synthesised curcumin-loaded nanocomplexes were administered in tumour-bearing laboratory animals (Lewis lung cancer model) and showed adequate contrast to enable in vivo and ex vivo study of UCNP-PLGA-nanocurcumin bio distribution in organs, with dominant distribution in the liver and lungs. Our studies demonstrate promise of nanocurcumin-loaded upconversion nanoparticles for theranostics applications.

Patients with metastatic melanoma are difficult to treat and have a very poor prognosis because of high resistance to therapy. Recent evidence indicates that tumors could overcome death through autophagy, a survival mechanism, which cancer cells use under lack of energy and nutrient deprivation. Melanoma cells have different sensitivity to temozolomide (TMZ) treatment. In this study, we showed that the combination of autophagy inhibitors chloroquine or LY294002 and TMZ induced enhanced cytotoxicity of alkylating agents on human melanoma cell lines. All assays were performed on patient-derived melanoma cell lines. The effectiveness of the combined treatment of TMZ and autophagy inhibitors was determined using an MTT assay. Next, we analyzed the expression mRNA level of Beclin 1, LC3B, and p62/STSQM1 and the relative expression of LC3B protein under combined treatment. Autophagic flux was determined by analysis of colocalization of Lysotracker Red and LC3B puncta. Apoptosis was measured by Annexin V/PI staining. Cell cycle analyses were carried out by flow cytometry. We showed that autophagy inhibition could enhance melanoma cell death combined with TMZ therapy. Chloroquine synergistically enhanced the TMZ-induced growth arrest and increased the G0/G1 population in Mel Z and Mel IL cell lines, but not Mel MTP. The expression analysis showed that autophagy involvement in TMZ enhanced cytotoxicity. Furthermore, LY294002, an early-stage autophagy, and PI3K inhibitor were found to exert similar effects. Both chloroquine and LY294002 improved the cytotoxic effect of TMZ treatment, making this combination applicable as a potent antitumor treatment for metastatic melanoma.

Recently introduced upconversion nanoparticles (UCNPs) have pushed the depth of photodynamic therapy (PDT) treatment to the centimetre range by converting deeply-penetrating near-infrared (NIR) radiation to visible radiation for photoexcitation of PDT drugs. Here we demonstrate that the direct exposure of the cancer tissue to phototoxic ultraviolet radiation generated by NIR-photoexcited UCNPs enabled successful PDT. To this aim, core/shell UCNPs of the formula NaYF4:Yb3+Tm3+/NaYF4 featuring an enhanced band in the ultraviolet UV-A and UV-B spectral bands were rationally designed and synthesised. Coupling UCNPs to the recombinant modules of the Designed Ankyrin Repeat Protein (DARPin) fused to a fluorescent protein mCherry allowed the target delivery of DARPin-mCherry/UCNP to human breast adenocarcinoma SK-BR-3 cells overexpressing HER2/neu receptors, as confirmed by fluorescence microscopy. DARPin-mCherry/UCNPs were demonstrated to be phototoxic to SK-BR-3 cells under 975 nm laser irradiation at a dose of 900 J cm−2 due to the UV photoexcitation of endogenous photosensitizers and concomitant generation of reactive oxygen species. The Lewis lung cancer mouse model was employed to demonstrate the feasibility of PDT using UCNP-mediated UV excitation of endogenous photosensitizers in the tumor tissue at a NIR dose of 1200 J cm−2. This study paves the way for exploring and harnessing UV photoexcitation processes in deep tissues in vivo.

Melanoma is one of the most aggressive and lethal form of cancer. Photodynamic therapy (PDT) is a clinically approved technique for cancer treatment, including non-melanoma skin cancer. However, the most of conventional photosensitizers are of low efficacy against melanoma due to the possible dark toxicity at high drug concentrations, melanin pigmentation, and induction of anti-oxidant defense mechanisms. In the current research we propose non-toxic flavin mononucleotide (FMN), which is a water-soluble form of riboflavin (vitamin B2) as a promising agent for photodynamic therapy of melanoma. We demonstrated selective accumulation of FMN in melanoma cells in vivo and in vitro in comparison with keratinocytes and fibroblasts. Blue light irradiation with dose 5 J/cm2 of melanoma cells pre-incubated with FMN led to cell death through apoptosis. Thus, the IC50 values of human melanoma A375, Mel IL, and Mel Z cells were in a range of FMN concentration 10–30 µM that can be achieved in tumor tissue under systemic administration. The efficiency of reactive oxygen species (ROS) generation under FMN blue light irradiation was measured in single melanoma cells by a label-free technique using an electrochemical nanoprobe in a real-time control manner. Melanoma xenograft regression in mice was observed as a result of intravenous injection of FMN followed by blue-light irradiation of tumor site. The inhibition of tumor growth was 85–90% within 50 days after PDT treatment.

Prospects for using upconversion nanoparticles as markers for tumor optical imaging are discussed. Using a model of epidermoid Lewis lung carcinoma engrafted in mice, luminescent signals from nanoparticles delivered into the tumor tissue are registered in vivo.

A novel surface modification approach of brightly luminescent upconversion nanoparticles (UCNPs) is reported. Inorganic core@shell UCNPs (core – NaYF4 co-doped with Yb3+ and Tm3+ ions, shell – NaYF4) were modified by intercalation with amphiphilic copolymer poly(maleic anhydride-alt-1-octadecene) followed by cross-linking with poly(ethylene glycol) diglycidyl ether (PEG-DGE). The proposed approach enables preparation of UCNPs with an outmost PEG-containing layer, which provides steric stabilization and low non-specific protein adsorption. Intravenous injection of PEG-functionalized UCNPs into the mice results in extension of the UCNP blood circulation time up to 1 hour. In vivo epi-luminescence imaging of the mouse model with Lewis lung carcinoma is ensured by the high quantum yield of the modified UCNPs and passive targeting associated with efficient UCNP accumulation in solid tumors.

Melanoma is one of the most aggressive and treatment-resistant tumors that responsible for majority of skin-cancer related deaths. Here we propose a combination of MEK inhibitor binimetinib with metformin as a promising therapy against human melanoma cells in vitro, including BRAF -mutated A375, Mel Z, and Mel IL cells, and NRAS-mutated Mel MTP and Mel Me cells. Additionally, we obtained two close to clinical practice models of melanoma progression. The first one was vemurafenib-resistant Mel IL/R melanoma cells with acquired resistance to BRAF inhibition-targeted therapy, and the second one was tumor spheroids, which are 3D in vitro model of small-size solid tumors in vivo. The cytotoxicity of binimetinib and metformin was synergistic in both 2D and 3D melanoma culture and mediated through apoptotic pathway. The combination reduced the number of melanoma-formed colonies, inhibited cell invasion and migration, and led to G0/G1 cell cycle arrest through cyclin D/CDK4/CDK6 pathway. The mechanism of metformin and binimetinib synergy in melanoma cells was associated with increased activation of p-AMPKα and decreased p-ERK, but not with alterations in p-mTOR. In summary, the combination of metformin and binimetinib resulted in stronger anti-proliferative effects on melanoma cells compared to binimetinib alone, and therefore could be promising for clinical applications.

Lanthanide-based upconversion nanoparticles attach great attention in theranostics due to their unique physicochemical and optical properties. It is innovative platform possessing peculiar properties for luminescent imaging, temperature mapping, sensing, and therapy. In present work we demonstrate advantages of new luminescent agents based on upconversion nanoparticles and hydrophylic biocompatible polymer.

In recent years, the overwhelming majority of the upconversion nanoparticles (UCNPs) prominent applications have originated from their unique luminescent properties. Due to original properties of inorganic UCNPs they attract the interest in numerous fields. We discussed a number of UCNP assisted techniques, such as biomedical imaging, therapy agents, anti-counterfeit labels and 3D printing, showing highly versatile and translatable UCNP photoluminescent nanotechnology for the applications in industry and biomedicine.

The discovery of B-RAF activating mutations in malignant melanoma cells has led to the development of a number of targeted drugs, which block exclusively the mutant B-RAF protein. Tumor cells often acquire resistance to B-RAF inhibitors via activation of alternative signaling pathways. One of the resistance mechanisms is activation of PDGF, VEGF, c-KIT, and certain other tyrosine kinases. The possibility of overcoming the resistance to the B-RAF inhibitor Vemurafenib by inactivating receptor tyrosine kinases (RTKs) was studied in metastatic melanoma cell lines differing in B-RAF mutations and RTK activity. It was found that RTK inactivation may help to overcome resistance to B-RAF inhibitors via inhibition of tyrosine kinase phosphorylation and a subsequent blocking of the PI3K-AKT-mTOR and MEK-ERK1/2 downstream signaling pathways. The changes eventually mitigated the cell growth and enhanced the Vemurafenib-dependent cell cycle arrest.

Riboflavin (Rf) is a vitamin and endogenous photosensitizer capable to generate reactive oxygen species (ROS) under UV-blue irradiation and kill cancer cells, which are characterized by the enhanced uptake of Rf. We confirmed its phototoxicity on human breast adenocarcinoma cells SK-BR-3 preincubated with 30-μM Rf and irradiated with ultraviolet light, and proved that such Rf concentrations (60 μM) are attainable in vivo in tumour site by systemic intravascular injection. In order to extend the Rf photosensitization depth in cancer tissue to 6 mm in depth, we purpose-designed core/shell upconversion nanoparticles (UCNPs, NaYF4:Yb3+:Tm3+/NaYF4) capable to convert 2% of the deeply-penetrating excitation at 975 nm to ultraviolet-blue power. This power was expended to photosensitise Rf and kill SK-BR-3 cells preincubated with UCNPs and Rf, where the UCNP-Rf energy transfer was photon-mediated with ~14% Förster process contribution. SK-BR-3 xenograft regression in mice was observed for 50 days, following the Rf-UCNPs peritumoural injection and near-infrared light photodynamic treatment of the lesions.

Dendritic cells (DC) belong to the most effective antigen-presenting cells. Their role in the presentation of thymus-dependent antigens and initiation of primary immune response is well known. At the same time, participation of DC in the immune response to T-independent antigens of type 2 (TI-2 antigens) is poorly explored. In this work, the ability of DC to initiate the immune response to a TI-2 antigen α(1→3) dextran (Dex) is investigated. Mouse bone-marrow-derived DC were generated by culturing the precursors with GM-CSF and then DC were pulsed by TI-2 antigens. The pulse induced DC activation, as was verified by an increase in the number of CD80 and CD86 positive cells. Uptake of FITC-labeled Dex was examined by flow cytometry. At a concentration of FITC-Dex of 100 μg/106 cells, the number of DC binding the antigen (Ag) reached “plateau”. DC charged by TI-2 antigens were mixed with normal mouse splenocytes and cultivated in RPMI-1640 medium for 4 days. The numbers of antibody- and immunoglobulin-forming cells were determined by ELISPOT method. The mixtures of splenocytes and naive DC not charged by the Ag were used as control. It was shown that the increase in the numbers of AFC and IFC under the influence of naive DC did not exceed 20%. On the contrary, the addition of DC pulsed by the Ag increased specific immune response more than twofold. The data obtained point to the direct interactions of DC with TI-2 antigens. Pulsed DC present TI-2 antigens to mouse splenocytes and induce specific and polyclonal B-cell activation, i.e., possess immunostimulating activity.

In this work are shown the prospects of using upconversion nanoparticles (UCNPs) as markers for contrast optical imaging of a tumor. For using nanoparticles for biomedical purposes is implemented a technique for coating nanoparticles with polymers, such as PEG and PSA. This approach provides low non-specific adsorption, which prolongs the circulation of UCNPs in mouse bearing Lewis Lung Cancer (LLC) up to 10 hours. These properties allow nanoparticles to quickly accumulate in the tumor. Effective delivery of particles with different polymer coatings in the tumor is demonstrated with the help of an epiluminescent imaging system.

Dendritic cells (DC) play a key role in adaptive immune response. By virtue of their extremely wide distribution and high populational diversity, DC interact with almost all types of immune cells linking innate and adaptive immunity. Due to great diversity of receptors, DC recognize a lot of pathogenic microorganisms and namely DC are responsible for the subsequent immune response. Inflammation triggers maturation of DC, which manifests itself in intracellular rearrangement and in appearance of costimulating molecules (CD40, CD80 and CD86) on DC surface. DC capture and process antigens keeping high amount of immunogenic peptides which are then presented to naive lymphocytes and induce their differentiation into effector cells. Depending on pathogen type and cytokine microenvironment, DC induce polarization of immune responses. In the absence of proinflammatory factors DC induce tolerance. In addition, DC play a crucial role in T-lymphocyte selection and Treg formation. The basic traits of DC biology are reviewed.

Alofanib is a potential allosteric inhibitor of FGFR2 used in oncology. The inhibitor blocks the extracellular part of the receptor and prevents its binding with the ligand. Alofanib suppressed proliferation of endothelial cells, their migration activity, and ability to form vessellike structures in vitro and significantly decreased the number of microvessels in Matrigel implant and in ovarian cancer (SKOV-3) xenograft in vivo. The results indicate that Alofanib can inhibit angiogenesis.

Alofanib (formerly known as RPT835) is a novel allosteric FGFR2 inhibitor with activity in FGFR2-expressing triple-negative breast cancer [Tjulandin S, et al. San Antonio Breast Cancer Symposium 2014]. Early data suggest that combining FGFR2 inhibitors with platinum-containing cytotoxic agents for the treatment of epithelial ovarian cancer may yield increased antitumor activity [Cole C, et al. Cancer Biol Ther. 2010]. We investigated antitumor activity of alofanib in ovarian cancer in vitro and in vivo. To assess the efficacy of alofanib on FGF-mediated cell proliferation, ovarian cancer (SKOV-3) FGFR2-expressing cells were incubated in a 96-well microculture plate and were treated with serially diluted RPT835. Basic FGF was added at a concentration of 25 ng/ml. Control wells were left untreated. Cell growth inhibition was determined using Promega's Cell Titer-Glo® assay. Immunocompromised mice were used for xenotransplantation of FGFR2 high-expressing ovarian cancer cells (SCOV-3). Seventy animals with measurable tumors were selected on day 10 and randomized into control groups (no treatment or chemotherapy alone (paclitaxel + carboplatin) and treatment groups (alofanib orally or intravenously (different dose levels) in combination with chemotherapy). Measurements of tumor volume (mm3) were performed by digital calipers every 3 days during 30 days after tumor inoculation. Basic FGF significantly increased proliferation of the ovarian cancer cells in untreated control group (P = 0.001). Alofanib treatment resulted in growth inhibition of SKOV-3 cell line in vitro. Treatment of alofanib in combination with paclitaxel/carboplatin demonstrated significant tumor growth delay phenotype in all treatment groups compared to control non-treatment groups. Alofanib exhibited a dose-dependent effect on tumor growth. Daily intravenous regimen of alofanib (total maximum dose per week was 350 mg/kg) demonstrated dramatic effect (inhibiting growth by 80% and by 53% in comparison with vehicle and chemotherapy group alone, respectively (P These results provide strong rationale for evaluation of alofanib in combination with paclitaxel and carboplatin in patients with ovarian cancer. Citation Format: Sergei Tjulandin, Mikhail Byakhov, Evgenia Stepanova, Dmitry Khochenkov, Daniel Harrison, Ilya Tsimafeyeu. Alofanib, a novel allosteric FGFR2 inhibitor, shows potent antitumor activity in ovarian cancer with FGFR2 expression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 796. doi:10.1158/1538-7445.AM2015-796