Prodrugs for nitroreductase based cancer therapy-4: Towards prostate cancer targeting: Synthesis of N-heterocyclic nitro prodrugs, Ssap-NtrB enzymatic activation and anticancer evaluation.

In this study, various N-heterocyclic nitro prodrugs (NHN1-16) containing pyrimidine, triazine and piperazine rings were designed and synthesized. The final compounds were identified using FT-IR, 1H NMR, 13C NMR as well as elemental analyses. Enzymatic activities of compounds were conducted by using HPLC analysis to investigate the interaction of substrates with Ssap-NtrB nitroreductase enzyme. MTT assay was performed to evaluate the toxic effect of compounds against Hep3B and PC3 cancer cell lines and healthy HUVEC cell. It was observed that synthesized compounds NHN1-16 exhibited different cytotoxic profiles. Pyrimidine derivative NHN3 and triazine derivative NHN5 can be good drug candidates for prostate cancer with IC50 values of 54.75 µM and 48.9 µM, respectively. Compounds NHN6, NHN10, NHN12, NHN14 and NHN16 were selected as prodrug candidates because of non-toxic properties against three different cell models. The NHN prodrugs and Ssap-NtrB combinations were applied to SRB assay to reveal the prodrug capabilities of these selected compounds. SRB screening results showed that the metabolites of all selected non-toxic compounds showed remarkable cytotoxicity with IC50 values in the range of 1.71-4.72 nM on prostate cancer. Among the tested compounds, especially piperazine derivatives NHN12 and NHN14 showed significant toxic effect with IC50 values of 1.75 nM and 1.79 nM against PC3 cell compared with standart prodrug CB1954 (IC50: 1.71 nM). Novel compounds NHN12 and NHN14 can be considered as promising prodrug candidates for nitroreductase-prodrug based prostate cancer therapy.

Is phenytoin a safe agent for staple line recovery after gastric sleeve surgery in rats?

BACKGROUND: The most challenging and mortal complication of gastric sleeve surgery (SG) is staple line leakage. Although many agents have been used for increasing tissue healing on the stapler line, there is still no consensus on its effectiveness and efficacy. The aim of study is to determine the effect of phenytoin on the healing process of gastric sleeve surgery in rats. METHODS: On the 10th post-operative day, the effects of phenytoin on bursting pressure in the stapler line were evaluated along-side pathohistological examinations. To investigate the molecular impact of phenytoin on the expression of TGF-ß, VEGF, FGF2, and p53 genes, quantitative real-time polymerase chain reaction was utilized. In addition, gene expressions at the protein level were deter-mined by immunohistochemical analysis. RESULTS: No signs of intra-abdominal leakage were observed in the resected samples. A statistically essential extend in stable line bursting pressure measure was observed between the control group and the group treated with phenytoin application. Pathohisto-logical results indicate that the mean score of collagens of the study group (3.2±0.42) was significantly higher than the control group (2.3±0.48) (P=0.003). In addition, the mean epithelization score of the study group (3.4±0.52) was significantly higher than the control group (2.1±0.57) (P=0.001). mRNA of TGFß, FGF2, VEGF, and p53 genes drastically increased phenytoin treated group. High FGF2 protein expression levels were determined from phenytoin use compared to the control group. CONCLUSION: Molecular studies suggest that phenytoin may increase the healing process of Gastric sleeve following SG in rats and may become a new agent for the prevention of human gastric leaks.

Investigation of the effects of post-operative intraperitoneal, oral, and rectal phenytoin administration on colorectal anastomosis in rats.

BACKGROUND: Anastomotic leakage is the most feared complication after colonic anastomosis. The purpose of the study is to determine the effects of phenytoin applied by different application routes, on the healing process of colorectal anastomoses. METHODS: Wistar Albino rats were divided into Intraperitoneal Phenytoin Group, Oral Phenytoin Group (OAP), Rectal Phenytoin Group (RAP), and control groups. The molecular effect of phenytoin on the expression of vascular endothelial growth factor (VEGF), transforming growth factor-beta (TGF-ß), fibroblast growth factor 2 (FGF2), and p53 genes was evaluated at mRNA and protein level. The effects of phenytoin on anastomotic bursting pressure analysis measured as well as pathohistological examinations. RESULTS: There are statistically significant increase in anastomotic bursting pressure values between control and application groups. Inflammatory cell infiltration of all groups increased in the intestinal anastomosis region compared to control. Collagen scores were found to be significantly higher in the OAP and RAP groups compared to the control group. mRNA of TGF-ß and FGF2 expression increased in all routes of phenytoin applications. CONCLUSION: Three different administration routes show considerably increase on the bursting pressure. Regarding the results of the expression of FGF2, TGF-ß, p53, and VEGF genes, there is a significant increase FGF2 and TGF-ß at mRNA and protein level in most administration routes.

Prodrugs for nitroreductase-based cancer therapy-3: Antitumor activity of the novel dinitroaniline prodrugs/Ssap-NtrB enzyme suicide gene system: Synthesis, in vitro and in silico evaluation in prostate cancer.

Prodrugs for targeted tumor therapies have been extensively studied in recent years due to not only maximising therapeutic effects on tumor cells but also reducing or eliminating serious side effects on healthy cells. This strategy uses prodrugs which are safe for normal cells and form toxic metabolites (drugs) after selective reduction by enzymes in tumor tissues. In this study, prodrug candidates (1-36) containing nitro were designed, synthesized and characterized within the scope of chemical experiments. Drug-likeness properties of prodrug candidates were analyzed using DS 2018 to investigate undesired toxicity effects. In vitro cytotoxic effects of prodrug canditates were performed with MTT assay for human hepatoma cells (Hep3B) and prostate cancer cells (PC3) and human umbilical vein endothelial cells (HUVEC) as healthy control. Non-toxic compounds (3, 5, 7, 10, 12, 15, 17, 19 and 21-23), and also compounds (1, 2, 5, 6, 9, 11, 14, 16, 20 and 24) which had low toxic effects, were selected to examine their suitability as prodrug canditates. The reduction profiles and kinetic studies of prodrug/Ssap-NtrB combinations were performed with biochemical analyses. Then, selected prodrug/Ssap-NtrB combinations were applied to prostate cancer cells to determine toxicity. The results of theoretical, in vitro cytotoxic and biochemical studies suggest 14/Ssap-NtrB, 22/Ssap-NtrB and 24/Ssap-NtrB may be potential prodrug/enzyme combinations for nitroreductase (Ntr)-based prostate cancer therapy.

PRODRUGS FOR NITROREDUCTASE BASED CANCER THERAPY- 2: Novel amide/Ntr combinations targeting PC3 cancer cells.

The use of nitroreductases (NTR) that catalyze the reduction of nitro compounds by using NAD(P)H in GDEPT (Gene-directed enzyme prodrug therapy) studies which minimize toxicity at healthy cells and increases concentration of drugs at cancer cells is remarkable. Discovery of new prodrug/NTR combinations is necessary to be an alternative to known prodrug candidates such as CB1954, SN23862, PR-104A. For this aim, nitro containing aromatic amides (A1-A23)2 were designed, synthesized, performed in silico ADMET and molecular docking techniques in this study. Prodrug candidates were studied on reduction potentials with Ssap-NtrB by HPLC system. Also, cyototoxic properties and prodrug ability of these amides were investigated using different cancer cell lines such as Hep3B and PC3. As a result of theoretical and biological studies, combinations of A5, A6 and A20 with Ssap-NtrB can be suggested as potential prodrugs/enzyme combinations at NTR based cancer therapy compared with CB1954/NfsB.