Metastatic hepatocarcinoma he/de tumor model in rat

NGR-Based Radiopharmaceuticals for Angiogenesis Imaging: A Preclinical Review

Angiogenesis plays a crucial role in tumour progression and metastatic spread; therefore, the development of specific vectors targeting angiogenesis has attracted the attention of several researchers. Since angiogenesis-associated aminopeptidase N (APN/CD13) is highly expressed on the surface of activated endothelial cells of new blood vessels and a wide range of tumour cells, it holds great promise for imaging and therapy in the field of cancer medicine. The selective binding capability of asparagine-glycine-arginine (NGR) motif containing molecules to APN/CD13 makes radiolabelled NGR peptides promising radiopharmaceuticals for the non-invasive, real-time imaging of APN/CD13 overexpressing malignancies at the molecular level. Preclinical small animal model systems are major keystones for the evaluation of the in vivo imaging behaviour of radiolabelled NGR derivatives. Based on existing literature data, several positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radioisotopes have been applied so far for the labelling of tumour vasculature homing NGR sequences such as Gallium-68 (68Ga), Copper-64 (64Cu), Technetium-99m (99mTc), Lutetium-177 (177Lu), Rhenium-188 (188Re), or Bismuth-213 (213Bi). Herein, a comprehensive overview is provided of the recent preclinical experiences with radiolabelled imaging probes targeting angiogenesis.

Apoptotic Janus-faced mycotoxins against thoracal and breast metastases

Abdominal organs (liver, kidney, spleen) are frequent targets of cancer cell invasion but their primary tumours are less known for their metastatic potential to other organs e.g. to the breast. Despite the known connection of the pathogenesis from breast cancer to liver metastasis, the study of the spread in the opposite direction has been neglected. The notion that breast cancer could be a metastasis besides being a primary tumour is based on rodents' tumour models upon implantation of tumour cells under the capsule of the kidney or under the Glisson's capsule of the liver of rats and mice. Tumour cells develop into a primary tumour at the site of subcutaneous implantation. The metastatic process starts with peripheral disruptions of blood vessels near the surface of primary tumours. Tumour cells released into the abdomen cross the apertures of the diaphragm, enter the thoracal lymph nodes and accumulate in parathymic lymph nodes. Abdominal colloidal carbon particles injected into the abdomen faithfully mimicked the migration of tumour cells and deposited in parathymic lymph nodes (PTNs). An explanation is provided why the connection between abdominal tumours and mammary tumours escaped attention, notably, parathymic lymph nodes in humans were referred to as internal mammary or parasternal lymph nodes. The apoptotic effect of Janus-faced cytotoxins is suggested to provide a new approach against the spread of abdominal primary tumours, and metastatic development.

Subrenal Capsule Assay - SRCA: The Promising Re-Emergence of a Long-Forgotten Method in Preclinical Nuclear Medical Cancer Diagnostics

Since metastases are responsible for the majority of cancer-related death, in-depth understanding of metastatisation may provide an opportunity for the introduction of new therapeutic as well as diagnostic approaches in cancer management. Previously, preclinical research into the development and progression of malignancies has been hampered by the relative paucity of in vivo tumor models. Subrenal capsule assay (SRCA)-induced tumor-bearing experimental animal models, however, serve as potential preclinical model systems for the assessment of primary tumors and the route of metastatic spread. Several studies implementing either Hepatocarcinoma (He/De), Mesoblastic Nephroma (Ne/De), chemically induced Myeloid Leukemia (My1/De), or spontaneous Myeloid Myelomonocytic Leukemia (My2/De) cells under the left renal capsule of rats applying SRCA method were underway to study secondary tumor formation. Based on the results of this research, subrenally transplanted neoplastic cells led to the appearance of metastasis in the parathymic lymph nodes. Therefore, renal capsule/parathymic lymph node complex seems to be valuable in the in vivo evaluation of the process of metastatisation and the occurrence of secondary neoplasms. The re-emergence of this highly promising SRCA-based renal capsule/parathymic lymph node complex in preclinical nuclear medicine and experimental oncology may open a novel field towards drug trials and radiopharmaceutical development. In the present review, we provide a detailed overview of the history of SRCA as well as the series of research on the establishment of renal capsule/parathymic lymph node complex.

Disturbance of myocardial metabolism participates in autoantibodies against β1 -adrenoceptor-induced cardiac dysfunction

Cardiac dysfunction is involved in disorders of energy metabolism. High-titre autoantibodies against the β1 -adrenoceptor (β1 -AAs) have been reported to exist in patients with cardiac dysfunction; however, the mechanism by which β1 -AAs affect cardiac function is unknown. This study aimed to determine whether β1 -AAs disturb myocardium energy metabolism and cause cardiac dysfunction. β1 -AA monoclonal antibodies (β1 -AAmAbs) were successfully pre-synthesized by hybridoma clones and used in all experiments. β1 -AAmAbs impaired cardiac function and induced a myocardial metabolic disturbance, as evidenced by decreased left ventricular ejection fraction and fractional shortening. In addition, β1 -AAmAbs decreased the adenosine triphosphate level and increased cardiac energy consumption (rate-pressure product). We further showed that the effects of β1 -AAmAbs on heart tissue might involve the mitochondria and metabolic pathways via the β1 -adrenoceptor based on an immunoprecipitation and mass spectrometry. Additionally, we found that β1 -AAmAbs impaired myocardial mitochondrial structure, decreased the membrane potential, and induced insufficient mitophagy. In conclusion, β1 -AAmAb-induced cardiac dysfunction is partly due to a disturbance in myocardial energy metabolism.

In vivo assessment of aminopeptidase N (APN/CD13) specificity of different 68Ga-labelled NGR derivatives using PET/MRI imaging

Aminopeptidase N (APN/CD13) plays an important role in neoangiogenic process in malignancies. Our previous studies have already shown that ⁶⁸Ga-labelled NOTA conjugated asparagine-glycine-arginine peptide (c[KNGRE]-NH₂) specifically bind to APN/CD13 expressing tumors. The aim of this study was to evaluate and compare the APN/CD13 specificity of newly synthesized ⁶⁸Ga-labelled NGR derivatives in vivo by PET/MRI imaging using hepatocellular carcinoma (He/De) and mesoblastic nephroma (Ne/De) tumor models. PET/MRI and ex vivo biodistribution studies were performed 11 ± 1 days after subcutaneous injection of tumor cells and 90 min after intravenous injection of ⁶⁸Ga-NOTA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR) (MG1) or ⁶⁸Ga-NODAGA-c(NGR) (MG2). The APN/CD13 selectivity was confirmed by blocking experiments and the APN/CD13 expression was verified by immunohistochemistry. ⁶⁸Ga-labelled c(NGR) derivatives were produced with high specific activity and radiochemical purity. In control animals, low radiotracer accumulation was found in abdominal and thoracic organs. Using tumor-bearing animals we found that the ⁶⁸Ga-NOTA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR), and ⁶⁸Ga-NODAGA-c(NGR) (MG1) derivatives showed higher uptake in He/De and Ne/De tumors, than that of the accumulation of ⁶⁸Ga-NODAGA-c(NGR) (MG2). APN/CD13 is a very promising target in PET imaging, however, the selection of the appropriate ⁶⁸Ga-labelled NGR-based radiopharmaceutical is critical for the precise detection of tumor neo-angiogenesis and for monitoring the efficacy of anticancer therapy.

Nephroprotective effect of Ferulago angulata flowers on N-nitrosodimethylamine-induced nephrotoxicity in rats and its phytochemical profile

The present study was designed to assess the phytochemical content of Ferulago angulata (FA) and possible in vivo nephroprotective effect of FA administration on trace elements, minerals, MDA and GSH in kidney and liver tissue samples, serum vitamin (α-tocopherol, retinol, cholecalciferol, phylloquinone), TSA, and LSA in a rat model of DMN-induced nephrotoxicity. In the study, Wistar albino rats were assigned to six groups: Control (0.9% NaCl), (DMN 10 mg/kg), (FA 150 mg/kg), (DMN + FA 150 mg/kg), (FA 300 mg/kg), and (DMN + FA 300 mg/kg). Rats were intraperitoneally given DMN for the first 7 days. Renal injury caused by DMN was proved by the histopathological alterations. The FA (300 mg/kg) treatment significantly normalized Se, Cr, Ca levels in liver and Co level in kidney tissue samples. These observed positive effects are due to the phytochemical content of the plant. The flower extract of FA (300 mg/kg) can be used for the prevention of kidney damage. PRACTICAL APPLICATIONS: Ferulago angulata flowers are used in traditional medicine for treat kidney and liver digestive system diseases. This species is endemic taxa of the family Apiaceae, which has been used both as food and therapeutics because of their phytochemical composition. In this study, the phenolic characterization of FA flower was used to a new RP-HPLC method, as well as the biological activity of FA flower and possible in vivo nephroprotective effect of FA flowers on trace elements, minerals, MDA and GSH in kidney and liver tissue samples and vitamins, TSA, and LSA in serum samples a rat model of DMN-induced nephrotoxicity. It was found that high level of phenolic compounds (chlorogenic acid, vanillic acid, 2-hydroxycinnamic acid) present in the flower extract of F. angulata has positive effects and antioxidant properties. Due to its phenolic content, FA flower extract could protect for kidney damage and can be used as antioxidants in the food additive and pharmaceutical industry.

Metastatic Spread from Abdominal Tumor Cells to Parathymic Lymph Nodes

Metastatic studies on rats showed that after subrenal implantation of tumor cells under the capsule of the kidney or subhepatic implantation under Glisson's capsule of the liver generated primary tumors in these organs. It was assumed that tumor cells that escaped through the disrupted peripheral blood vessels of primary tumors entered the peritoneal cavity, crossed the diaphragm, and appeared in the thoracal, primarily in the parathymic lymph nodes. This explanation did not answer the question whether distant lymph nodes were reached via the blood stream from the primary tumor or through the thoracal lymphatic vessels. In this work, we investigated the metastatic pathway in C3H/HeJ mice, after direct intraperitoneal administration of murine SCC VII cells bypassing the hematogenic spread of tumor cells. The direct pathway was also mimicked by intraperitoneal injection of Pelican Ink colloidal particles, which appeared in the parathymic lymph nodes, similarly to the tumor cells that caused metastasis in the parathymic lymph nodes and in the thymic tissue. The murine peritoneal-parathymic lymph node route indicates a general mechanism of tumor progression from the abdominal effusion. This pathway starts with the growth of abdominal tumors, continues as thoracal metastasis in parathymic lymph nodes and may proceed as mammary lymph node metastasis.

Modeling of Lymphogenous and Hematogenous Metastasizing from Murine В16 Melanoma in Rats

We developed a model of experimental melanoma. Intralienal xenogeneic transplantation of a suspension of melanoma cells B16 in physiological saline (0.1 ml; 1:10) was conducted to outbred male rats. In 6 months, histologically confirmed melanoma B16 in the spleen and its metastases in the liver, intestine, pancreas, adrenal glands, and lungs (hematogenous metastasis), as well as in the thymus and lymph nodes (lymphogenous metastasis) were revealed in rats. The proposed rat model of melanoma B16 metastasizes by the hematogenous and lymphogenous pathways, develops over 6 months, and allows receiving sufficient volume of material for analysis.

Nanodiamond-enhanced MRI via in situ hyperpolarization

Nanodiamonds are of interest as nontoxic substrates for targeted drug delivery and as highly biostable fluorescent markers for cellular tracking. Beyond optical techniques, however, options for noninvasive imaging of nanodiamonds in vivo are severely limited. Here, we demonstrate that the Overhauser effect, a proton–electron polarization transfer technique, can enable high-contrast magnetic resonance imaging (MRI) of nanodiamonds in water at room temperature and ultra-low magnetic field. The technique transfers spin polarization from paramagnetic impurities at nanodiamond surfaces to ¹H spins in the surrounding water solution, creating MRI contrast on-demand. We examine the conditions required for maximum enhancement as well as the ultimate sensitivity of the technique. The ability to perform continuous in situ hyperpolarization via the Overhauser mechanism, in combination with the excellent in vivo stability of nanodiamond, raises the possibility of performing noninvasive in vivo tracking of nanodiamond over indefinitely long periods of time.

Hyperpolarized magnetic resonance imaging can enhance imaging contrast by orders of magnitude, but applications are limited by the thermal relaxation of hyperpolarized states. Here, Waddington et al. demonstrate the on-demand hyperpolarization of hydrogen spins through the Overhauser effect with nanodiamonds.