Derivation of feline vaccine-associated fibrosarcoma cell line and its growth on chick embryo chorioallantoic membrane - a new in vivo model for veterinary oncological studies

Long non‑coding RNA LINC00238 suppresses the malignant phenotype of liver cancer by sponging miR‑522

Long non‑coding RNAs can regulate the malignant tumor phenotype either as tumor suppressors or oncogenes. The present study investigated the underlying mechanism of LINC00238 in liver cancer. LINC00238 was identified as a downregulated molecule in The Cancer Genome Atlas liver hepatocellular carcinoma dataset through Gene Expression Profiling Interactive Analysis software. Through gain‑ and loss‑of‑function experiments, LINC00238 was confirmed as a tumor suppressor that could not only decrease cell viability, migration and invasion in vitro, but also tumorigenesis and tumor metastasis in vivo. By cytoplasmic and nuclear RNA isolation, LINC00238 was confirmed to be predominantly cytoplasmic. Mechanistically, RNA pull‑down assays showed that LINC00238 sponged microRNA (miR)‑522 and then reversed the inhibitory effects on two downstream targets, secreted frizzled related protein 2 and dickkopf1. Collectively, LINC00238 was identified as a tumor suppressor that acts via sponging miR‑522 followed by silencing of downstream targets, suggesting that LINC00238 may have a key role in suppressing the malignant phenotype of liver cancer cells.

Proteomic Differences in Feline Fibrosarcomas Grown Using Doxorubicin-Sensitive and -Resistant Cell Lines in the Chick Embryo Model

Proteomic analyses are rapid and powerful tools that are used to increase the understanding of cancer pathogenesis, discover cancer biomarkers and predictive markers, and select and monitor novel targets for cancer therapy. Feline injection-site sarcomas (FISS) are aggressive skin tumours with high recurrence rates, despite treatment with surgery, radiotherapy, and chemotherapy. Doxorubicin is a drug of choice for soft tissue sarcomas, including FISS. However, multidrug resistance is one of the major causes of chemotherapy failure. The main aim of the present study was to identify proteins that differentiate doxorubicin-resistant from doxorubicin-sensitive FISS using two-dimensional gel electrophoresis (2DE), followed by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Using the three-dimensional (3D) preclinical in ovo model, which resembles features of spontaneous fibrosarcomas, three significantly (p ≤ 0.05) differentially expressed proteins were identified in tumours grown from doxorubicin-resistant fibrosarcoma cell lines (FFS1 and FFS3) in comparison to the doxorubicin-sensitive one (FFS5): Annexin A5 (ANXA5), Annexin A3 (ANXA3), and meiosis-specific nuclear structural protein 1 (MNS1). Moreover, nine other proteins were significantly differentially expressed in tumours grown from the high doxorubicin-resistant cell line (FFS1) in comparison to sensitive one (FFS5). This study may be the first proteomic fingerprinting of FISS reported, identifying potential candidates for specific predictive biomarkers and research targets for doxorubicin-resistant FISS.

Current knowledge on feline injection-site sarcoma treatment

Feline injection-site sarcomas (FISS) are malignant skin tumours of mesenchymal origin, the treatment of which is a challenge for veterinary surgeons. The role of surgery, radiotherapy and chemotherapy in FISS treatment has been studied, and a correlation between “clean” surgical margins and disease-free survival has been shown. In addition, clean surgical margins are one of the most important factors for achieving a low recurrence rate. The most effective method of FISS treatment includes combining radical surgery with pre- or postoperative radiotherapy. Chemotherapy may be used as a palliative method of treatment or may be considered an adjunctive therapy for surgery and radiotherapy. In cats with FISS without metastasis, the use of immunostimulant treatment with Oncept IL-2, intended as a complementary immunotherapy in association with surgery and brachytherapy, may also be considered to reduce the risk of relapse and increase the time to relapse. Additionally, this review focuses on recent advances in FISS treatment, including the use of novel compounds, such as doxorubicin conjugated to glutathione-stabilized gold nanoparticles, liposomal doxorubicin or tyrosine kinase inhibitors.

Experimental tumor growth of canine osteosarcoma cell line on chick embryo chorioallantoic membrane (in vivo studies)

The chick embryo chorioallantoic membrane (CAM) model is extensively used in human medicine in preclinical oncological studies. The CAM model has several advantages: low cost, simple experimental approach, time saving and following "3R principles". Research has shown that the human osteosarcoma cell lines U2OS, MMNG-HOS, and SAOS can form tumors on the CAM. In veterinary medicine, this has been described only for feline fibrosarcomas, feline mammary carcinomas and canine osteosarcomas. However, in case of canine osteosarcomas, it has been shown that only non-adherent osteosarcoma stem cells isolated from KTOSA5 and CSKOS cell lines have the ability to form microtumors on the CAM after an incubation period of 5 days, in contrast to adherent KTOSA5 and CSKOS cells. In the presented study, we have proven that the commercial adherent canine osteosarcoma cell line (D-17) can form vascularized tumors on the CAM after the incubation period of 10 days.

Doxorubicin Conjugated to Glutathione Stabilized Gold Nanoparticles (Au-GSH-Dox) as an Effective Therapeutic Agent for Feline Injection-Site Sarcomas-Chick Embryo Chorioallantoic Membrane Study

Feline injection-site sarcomas are malignant skin tumours with a high local recurrence rate, ranging from 14% to 28%. The treatment of feline injection-site sarcomas includes radical surgery, radiotherapy and/or chemotherapy. In our previous study it has been demonstrated that doxorubicin conjugated to glutathione-stabilized gold nanoparticles (Au-GSH-Dox) has higher cytotoxic effects than free doxorubicin for feline fibrosarcoma cell lines with high glycoprotein P activity (FFS1, FFS3). The aim of the present study was to assess the effectiveness of intratumoural injection of Au-GSH-Dox on the growth of tumours from the FFS1 and FFS3 cell lines on chick embryo chorioallantoic membrane. This model has been utilized both in human and veterinary medicine for preclinical oncological studies. The influence of intratumoural injections of Au-GSH-Dox, glutathione-stabilized gold nanoparticles and doxorubicin alone on the Ki-67 proliferation marker was also checked. We demonstrated that the volume ratio of tumours from the FFS1 and FFS3 cell lines was significantly (p < 0.01) decreased after a single intratumoural injection of Au-GSH-Dox, which confirms the positive results of in vitro studies and indicates that Au-GSH-Dox may be a potent new therapeutic agent for feline injection-site sarcomas.

The use of rats and mice as animal models in ex vivo bone growth and development studies

In vivo animal experimentation has been one of the cornerstones of biological and biomedical research, particularly in the field of clinical medicine and pharmaceuticals. The conventional in vivo model system is invariably associated with high production costs and strict ethical considerations. These limitations led to the evolution of an ex vivo model system which partially or completely surmounted some of the constraints faced in an in vivo model system. The ex vivo rodent bone culture system has been used to elucidate the understanding of skeletal physiology and pathophysiology for more than 90 years. This review attempts to provide a brief summary of the historical evolution of the rodent bone culture system with emphasis on the strengths and limitations of the model. It encompasses the frequency of use of rats and mice for ex vivo bone studies, nutritional requirements in ex vivo bone growth and emerging developments and technologies. This compilation of information could assist researchers in the field of regenerative medicine and bone tissue engineering towards a better understanding of skeletal growth and development for application in general clinical medicine.Cite this article: A. A. Abubakar, M. M. Noordin, T. I. Azmi, U. Kaka, M. Y. Loqman. The use of rats and mice as animal models in ex vivo bone growth and development studies. Bone Joint Res 2016;5:610-618. DOI: 10.1302/2046-3758.512.BJR-2016-0102.R2.

Enhancing anti-tumor efficacy of Doxorubicin by non-covalent conjugation to gold nanoparticles - in vitro studies on feline fibrosarcoma cell lines

Background

Feline injection-site sarcomas are malignant skin tumors of mesenchymal origin, the treatment of which is a challenge for veterinary practitioners. Methods of treatment include radical surgery, radiotherapy and chemotherapy. The most commonly used cytostatic drugs are cyclophosphamide, doxorubicin and vincristine. However, the use of cytostatics as adjunctive treatment is limited due to their adverse side-effects, low biodistribution after intravenous administration and multidrug resistance. Colloid gold nanoparticles are promising drug delivery systems to overcome multidrug resistance, which is a main cause of ineffective chemotherapy treatment. The use of colloid gold nanoparticles as building blocks for drug delivery systems is preferred due to ease of surface functionalization with various molecules, chemical stability and their low toxicity.

Methods

Stability and structure of the glutathione-stabilized gold nanoparticles non-covalently modified with doxorubicin (Au-GSH-Dox) was confirmed using XPS, TEM, FT-IR, SAXRD and SAXS analyses. MTT assay, Annexin V and Propidium Iodide Apoptosis assay and Rhodamine 123 and Verapamil assay were performed on 4 feline fibrosarcoma cell lines (FFS1WAW, FFS1, FFS3, FFS5). Statistical analyses were performed using Graph Pad Prism 5.0 (USA).

Results

A novel approach, glutathione-stabilized gold nanoparticles (4.3 +/- 1.1 nm in diameter) non-covalently modified with doxorubicin (Au-GSH-Dox) was designed and synthesized. A higher cytotoxic effect (p<0.01) of Au-GSH-Dox than that of free doxorubicin has been observed in 3 (FFS1, FFS3, FFS1WAW) out of 4 feline fibrosarcoma cell lines. The effect has been correlated to the activity of glycoprotein P (main efflux pump responsible for multidrug resistance).

Conclusions

The results indicate that Au-GSH-Dox may be a potent new therapeutic agent to increase the efficacy of the drug by overcoming the resistance to doxorubicin in feline fibrosarcoma cell lines. Moreover, as doxorubicin is non-covalently attached to glutathione coated nanoparticles the synthesized system is potentially suitable to a wealth of different drug molecules.

An approach to local immunotoxicity induced by adjuvanted vaccines

The occurrence of injection site reactions following immunization is the most frequently reported toxicity manifestation of vaccines; however, the different types of local reactions and the different mechanisms involved are still unclear. Here, the current advances in adjuvants and the role that adjuvants play in local reactions are reviewed. The role of adjuvants in the formation of the loco-regional complex (LRC), which consists of the injection site, draining lymphatic vessels and regional lymph nodes, is also discussed. Finally, strategies and recommendations for the rational design of adjuvanted vaccines are discussed, with a particular interest in the reduction of local inflammation.