Molecular imaging of myogenic stem/progenitor cells with [18F]-FHBG PET/CT system in SCID mice model of post-infarction heart.

Preclinical and clinical studies have shown that stem cells can promote the regeneration of damaged tissues, but therapeutic protocols need better quality control to confirm the location and number of transplanted cells. This study describes in vivo imaging while assessing reporter gene expression by its binding to a radiolabelled molecule to the respective receptor expressed in target cells. Five mice underwent human skeletal muscle-derived stem/progenitor cell (huSkMDS/PC EF1-HSV-TK) intracardial transplantation after induction of myocardial infarction (MI). The metabolic parameters of control and post-infarction stem progenitor cell-implanted mice were monitored using 2-deoxy-18F-fluorodeoxyglucose ([18F]-FDG) before and after double promotor/reporter probe imaging with 9-(4-18F-fluoro-3-[hydroxymethyl]butyl)guanine ([18F]-FHBG) using positron emission tomography (PET) combined with computed tomography (CT). Standardized uptake values (SUVs) were then calculated based on set regions of interest (ROIs). Experimental animals were euthanized after magnetic resonance imaging (MRI). Molecular [18F]-FHBG imaging of myogenic stem/progenitor cells in control and post-infarction mice confirmed the survival and proliferation of transplanted cells, as shown by an increased or stable signal from the PET apparatus throughout the 5 weeks of monitoring. huSkMDS/PC EF1-HSV-TK transplantation improved cardiac metabolic ([18F]-FDG with PET) and haemodynamic (MRI) parameters. In vivo PET/CT and MRI revealed that the precise use of a promotor/reporter probe incorporated into stem/progenitor cells may improve non-invasive monitoring of targeted cellular therapy in the cardiovascular system.

Assessment of Immunological Potential of Glial Restricted Progenitor Graft In Vivo-Is Immunosuppression Mandatory?

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease, causing motor neuron and skeletal muscle loss and death. One of the promising therapeutic approaches is stem cell graft application into the brain; however, an immune reaction against it creates serious limitations. This study aimed to research the efficiency of glial restricted progenitors (GRPs) grafted into murine CNS (central nervous system) in healthy models and the SOD1G93A ALS disease model. The cellular grafts were administered in semiallogenic and allogeneic settings. To investigate the models of immune reaction against grafted GRPs, we applied three immunosuppressive/immunomodulatory regimens: preimplantation factor (PiF); Tacrolimus; and CTLA-4, MR1 co-stimulatory blockade. We tracked the cells with bioluminescence imaging (BLI) in vivo to study their survival. The immune response character was evaluated with brain tissue assays and multiplex ELISA in serum and cerebrospinal fluid (CSF). The application of immunosuppressive drugs is disputable when considering cellular transplants into the immune-privileged site/brain. However, our data revealed that semiallogenic GRP graft might survive inside murine CNS without the necessity to apply any immunomodulation or immunosuppression, whereas, in the situation of allogeneic mouse setting, the combination of CTLA-4, MR1 blockade can be considered as the best immunosuppressive option.

hTERT C250T promoter mutation and telomere length as a molecular markers of cancer progression in patients with head and neck cancer.

Squamous cell carcinoma of the head and neck (HNSCC) is the sixth leading cause of cancer worldwide, representing over half a million incidents every year. Cancer cells, including HNSCC, are characterized by increased telomerase activity. This enzymatic complex is active in ~90% of all cancer types and is responsible for the lengthening of telomeres. Highly recurrent point mutations in the human telomerase reverse transcriptase (hTERT) promoter have recently been reported in a number of human neoplasms. The aim of the present study was to analyze the prevalence of the hTERT promoter C250T mutation and telomere length in the blood leukocytes of 61 patients with HNSCC and 49 healthy individuals. Quantitative polymerase chain reaction identified the hTERT promoter mutation in 36% of patients with HNSCC. To the best of our knowledge this is first report indicating the presence of shorter telomeres in early stage tumors. In addition, the results suggest that the C250T hTERT promoter mutation and telomere length assessment may serve as important molecular markers of HNSCC progression.