Systemic Metabolic Signatures of Oral Diseases.

Systemic metabolic signatures of oral diseases have been rarely investigated, and prospective studies do not exist. We analyzed whether signs of current or past infectious/inflammatory oral diseases are associated with circulating metabolites. Two study populations were included: the population-based Health-2000 (n = 6,229) and Parogene (n = 452), a cohort of patients with an indication to coronary angiography. Health-2000 participants (n = 4,116) provided follow-up serum samples 11 y after the baseline. Serum concentrations of 157 metabolites were determined with a nuclear magnetic resonance spectroscopy-based method. The associations between oral parameters and metabolite concentrations were analyzed using linear regression models adjusted for age, sex, number of teeth, smoking, presence of diabetes, and education (in Health-2000 only). The number of decayed teeth presented positive associations with low-density lipoprotein diameter and the concentrations of pyruvate and citrate. Negative associations were found between caries and the unsaturation degree of fatty acids (FA) and relative proportions of docosahexaenoic and omega-3 FAs. The number of root canal fillings was positively associated with very low-density lipoprotein parameters, such as diameter, cholesterol, triglycerides, and number of particles. Deepened periodontal pockets were positively associated with concentrations of cholesterol, triglycerides, pyruvate, leucine, valine, phenylalanine, and glycoprotein acetyls and negatively associated with high-density lipoprotein (HDL) diameter, FA unsaturation degree, and relative proportions of omega-6 and polyunsaturated FAs. Bleeding on probing (BOP) was associated with increased concentrations of triglycerides and glycoprotein acetyls, as well as decreased proportions of omega-3 and omega-6 FAs. Caries at baseline predicted alterations in apolipoprotein B-containing lipoproteins and HDL-related metabolites in the follow-up, and both caries and BOP were associated with changes in HDL-related metabolites and omega-3 FAs in the follow-up. Signs of current or past infectious/inflammatory oral diseases, especially periodontitis, were associated with metabolic profiles typical for inflammation. Oral diseases may represent a modifiable risk factor for systemic chronic inflammation and thus cardiometabolic disorders.

Tomato thymidine kinase-based suicide gene therapy for malignant glioma--an alternative for Herpes Simplex virus-1 thymidine kinase.

Malignant gliomas (MGs) are the most common malignant primary brain tumors with a short life estimate accompanied by a marked reduction in the quality of life. Herpes Simplex virus-1 thymidine kinase ganciclovir (HSV-TK/GCV) system is the best characterized enzyme prodrug therapy in use. However, lipophobicity of GCV and low enzymatic activity of HSV-TK reduce the treatment efficacy. Tomato TK (ToTK) has shown high activity in combination with its specific substrate azidothymidine (AZT). The aim of this study was to evaluate whether ToTK/AZT could be used as an alternative to HSV-TK/GCV therapy. Both treatments demonstrated cytotoxicity in human MG cells in vitro. In vivo, both treatments decreased tumor growth and tumors were smaller in comparison with controls in mouse orthotopic MG model. Survival of ToTK/AZT-treated mice was significantly increased compared with control mice (*P<0.05) but not as compared with HSV-TK/GCV-treated mice. No significant differences were observed in clinical chemistry safety analyses. We conclude that both treatments showed a beneficial treatment response in comparison to controls on tumor growth and ToTK/AZT also on survival. There were no significant differences between these treatments. Therefore ToTK/AZT could be considered as an alternative treatment option for MG because of its favorable therapeutic characteristics.

Improved therapeutic effect on malignant glioma with adenoviral suicide gene therapy combined with temozolomide.

Malignant gliomas (MGs) are cancers with poor prognosis and limited therapeutic options. Herpes Simplex virus-1 thymidine kinase expressed from adenoviruses with prodrug ganciclovir (TK/GCV) is the best-characterized suicide gene therapy, whereas temozolomide (TMZ) is the first-line chemotherapy for MG. However, the potential of their combination has not been studied thoroughly. The aim of this study was to evaluate the therapeutic response of this combination and to study whether addition of valproic acid (VPA) could benefit the treatment outcome. Efficacies of different treatments were first studied in vitro in BT4C rat MG cells. Therapeutic assessment in vivo was done in an immunocompetent rat MG model for treatment efficacy and toxicity. In vitro, VPA was able to significantly enhance cytotoxicity and increase adenovirus-mediated transduction efficiency up to sevenfold. In vivo, rats receiving TK/GCV+TMZ had notably smaller tumors and enhanced survival (P<0.001) in comparison with control rats. However, VPA was not able to further enhance the treatment response in vivo. Leukocytopenia and thrombocytopenia were the major side effects. We conclude that careful optimization of the treatment schedules and doses of individual therapies are necessary to achieve an optimal therapeutic effect with TK/GCV+TMZ combination. No further in vivo benefit with VPA was observed.

Characterization of HIV-1 TAT peptide as an enhancer of HSV-TK/GCV cancer gene therapy.

Cancer suicide gene therapy based on herpes simplex virus type I thymidine kinase (HSV-TK) and ganciclovir (GCV) suffers from the lack of efficacy in clinical use, which is mostly due to low gene-transfer efficiency and absence of bystander effect in tumors. We have previously demonstrated the enhancement of GCV cytotoxicity by fusing the HSV-TK with the cell penetrating peptide from HIV-1 transactivator protein transduction domain (TAT PTD). Despite the earlier promising results, we found that the triple fusion protein HIV-1 transactivator protein transduction domain-thymidine kinase suicide gene-green fluorescent protein marker gene (TAT-TK-GFP) increased GCV cytotoxicity only in 3/12 of different human tumor cell lines. Extended GCV exposure enhanced the cytotoxic effect of HSV-TK/GCV gene therapy, but the difference between TK-GFP and TAT-TK-GFP was not statistically significant. The modest improvement on cell killing mediated by TAT PTD in Chinese hamster ovary cells appeared to be associated with cell-surface heparan sulfate proteoglycan (HSPG) composition. However, TAT-mediated increased cell death did not correlate with the density of cell-surface HSPG expression in different tumor cell lines. In conclusion, although some degree of enhancement by TAT was shown in certain tumor cells in vitro, it is unlikely that TAT peptide linked to a suicide protein could be a useful booster of in vivo gene therapy trials.