Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 18, Issue 6, 2018

Background: Over the past five years, the cold atmospheric plasma-activated solutions (PAS) have shown their promissing application in cancer treatment. Similar as the common direct cold plasma treatment, PAS shows a selective anti-cancer capacity in vitro and in vivo. However, different from the direct cold atmospheric plasma (CAP) treatment, PAS can be stored for a long time and can be used without dependence on a CAP device. The research on PAS is gradually becoming a hot topic in plasma medicine. Objectives: In this review, we gave a concise but comprehensive summary on key topics about PAS including the development, current status, as well as the main conclusions about the anti-cancer mechanism achieved in past years. The approaches to make strong and stable PAS are also summarized.

Objective: The aim of this work is to investigate the inhibitory effect of Plasma Activated Medium (PAM) on Head and Neck cancerous cells (FaDu). The response of FaDu cells in monolayer cultures and Multi Cellular Tumor Spheroids (MCTS) after treatment with different PAMs will be compared. Background: Head and Neck squamous cell carcinoma is a widespread cancer that responds poorly to anticancer treatments such as chemotherapy and radiotherapy. Nowadays there is a growing interest in cold plasmas and their applications in cancer therapy. Methods: A homemade helium plasma jet is used to produce PAM. The effects of PAM and hydrogen peroxide H2O2 on FaDu 2D cells cultures and MCTS were characterized by evaluating the cell viability with PrestoBlue test and by measuring the size of MCTS. Results: One treatment with PAM induce cell detachment from MCTS since the first day in a PAM exposure dependent manner. This is due to the presence of H2O2 in PAM. However, a rapid spheroids regrowth is observed attributed to a resistance of FaDu cells to H2O2. After multiple treatments of MCTS with PAM we obtained an inhibition of cell growth. MCTS are brought out when comparing PAM effect on 2D versus MCTS. Inversely, PAM induces cell death in the case of 2D cell culture. Conclusion: PAM may be considered as a potentially efficient agent in the therapy of head and neck cancer. We also point out that MCTS is a more valuable model than 2D cell culture for the evaluation of the anti-cancer activity of PAM.

Background: Application of cold atmospheric plasma to medium generates “plasma-activated medium” that induces apoptosis selectively in tumor cells and that has an antitumor effect in vivo. The underlying mechanisms are not well understood. Objective: Elucidation of potential chemical interactions within plasma-activated medium and of reactions of medium components with specific target structures of tumor cells should allow to define the active principle in plasma activated medium. Methods: Established knowledge of intercellular apoptosis-inducing reactive oxygen/nitrogen species-dependent signaling and its control by membrane-associated catalase and SOD was reviewed. Model experiments using extracellular singlet oxygen were analyzed with respect to catalase inactivation and their relevance for the antitumor action of cold atmospheric plasma. Potential interactions of this tumor cell-specific control system with components of plasma-activated medium or its reaction products were discussed within the scope of the reviewed signaling principles. Results: None of the long-lived species found in plasma-activated medium, such as nitrite and H2O2, nor OCl- or .NO seemed to have the potential to interfere with catalase-dependent control of apoptosis-inducing signaling of tumor cells when acting alone. However, the combination of H2O2 and nitrite might generate peroxynitrite. The protonation of peroxnitrite to peroxynitrous acid allows for the generation of hydroxyl radicals that react with H2O2, leading to the formation of hydroperoxide radicals. These allow for singlet oxygen generation and inactivation of membrane-associated catalase through an autoamplificatory mechanism, followed by intercellular apoptosis-inducing signaling. Conclusion: Nitrite and H2O2 in plasma-activated medium establish singlet oxygen-dependent interference selectively with the control system of tumor cells.

Objective: The aim of the paper is to investigate the optimum condition for generation of Plasma Activated Media (PAM), where it can deactivate the cancer cells while minimum damage for normal cells. Background: Over past few years, cold atmospheric Plasma-Activated Media (PAM) have shown its promising application in plasma medicine for treatment of cancer. PAM has a tremendous ability for selective anti-cancer capacity in vitro and in vivo. Methods: We have analyzed the radicals in air using the optical emission spectroscopy and in culture media using chemical analysis. Further, we have tested the toxicity of PAM using MTT assay. Results: We observed that more cancer cell death is for the Ar plasma followed by the Ar-N2 plasma, and the least cell death was observed for the Ar-O2 plasma at all treatment times both by direct treatment and through PAM treatment. The concentration of the RNS species is high for Ar-N2 plasma in gas as well as inside the culture media compared to that for pure Ar plasma. However, the difference is significantly less between the Ar plasma treatments and the Ar-N2 plasma treatments, showing that ROS is the main factor contributing to cell death. Conclusion: Among all three feeding gas plasmas the best system is Ar-O2 plasma for direct treatments towards the cancer cells. In addition, the best system for PAM preparation is Ar-N2 at low time treatments (1 min and 2 min) because it has no effect on normal cells, but kills the cancer cells.

Background: The use of plasma-activated liquids such as PBS, medium or simply plasma-activated water (PAW) has been receiving increasing attention for applications in cancer treatments. Amongst the reactive species contained in these solutions, hydrogen peroxide appears to play a pivotal role in causing cytotoxic effects. H2O2 concentrations can be correlated with reduced cell viability and growth and used as an indicator of the potential efficacy of a plasma-activated liquid. Objective: To investigate the cytotoxic mediators generated in water specific to high-voltage DBD-ACP. Method: Using a high-voltage dielectric barrier atmospheric cold plasma (DBD-ACP) system, we examined PAW-mediated cytotoxic effects on different mammalian cell lines employing a set-up where short-lived reactive species can be discounted and activated liquids with long-term stability are generated. Results: The PAW potency could be modulated using voltage level, treatment time and post-treatment storage time and target-related characteristics such as surface to volume ratio. All of these parameters effected cell viability in a hydrogen peroxide concentration correlated manner. The susceptibility of two cancer cell lines to PAW was similar to that observed for two non-cancer cell lines and the toxicity of plasma-activated water exceeded that of the corresponding hydrogen peroxide concentrations. Conclusion: In cytotoxic plasma activated water an essential role for H2O2 has been demonstrated multi-fold, yet further contributing factors are apparent and remain to be identified.

Background: Cold physical plasma has been suggested as a new anticancer tool recently. However, direct use of plasma is limited to visible tumors and in some clinical situations, is not feasible. This includes repetitive treatment of peritoneal metastases, which commonly occur in advanced gastrointestinal cancer and in pancreatic cancer in particular. In case of diffuse intraperitoneal metastatic spread, Hyperthermic Intraperitoneal Intraoperative Chemotherapy (HIPEC) is used as a therapeutic approach. Plasma-treated solutions may combine non-toxic characteristics with the anticancer effects of HIPEC. Previous work has provided evidence for an anticancer efficacy of plasma-treated cell culture medium but the clinical relevance of such an approach is low due to its complex formulation and lack of medical accreditation. Objective: Plasma-treated Phosphate-Buffered Saline (PBS), which closely resembles medically certified solutions, was investigated for its cytotoxic effect on 2D monolayer murine pancreatic cancer cells in vitro. Methods: Toxicity studies of primary murine fibroblasts, PDA6606 murine pancreatic cancer cells, and COLO 357 human pancreatic cancer cells exposed to plasma-treated PBS were performed. Results: Plasma-treated PBS significantly decreased cancer cell metabolisms and proliferation whereas plasma-treated Dulbecco's Modified Eagle Medium had no effect. Moreover, tumor cell growth attenuation was significantly higher when compared to syngeneic primary murine fibroblasts. Both results were confirmed in a human pancreatic cancer cell line. Finally, plasma-treated PBS also decreased the size of pancreatic tumors in a three-dimensional manner, and induction of apoptosis was found to be responsible for all anticancer effects identified. Conclusion: Plasma-treated PBS inhibited cell growth in 2D and 3D models of cancer. These results may help facilitate the development of new plasma-derived anticancer agent with clinical relevance in the future.

Traditionally, breast cancer (BC) is divided into different subtypes defined by immunohistochemistry (IHC) according to the expression of hormone receptors and overexpression/amplification of human epidermal growth factor receptor 2 (HER2), with crucial therapeutic implications. In the last few years, the definition of different BC molecular subgroups within the IHC-defined subtypes and the identification of the important role that molecular heterogeneity can play in tumor progression and treatment resistance have inspired the search for personalized therapeutic approaches. In this scenario, translational research represents a key strategy to apply knowledge from cancer biology to the clinical setting, through the study of all the tumors “omics”, including genomics, transcriptomics, proteomics, epigenomics, and metabolomics. Importantly, the introduction of new high-throughput technologies, such as next generation sequencing (NGS) for the study of cancer genome and transcriptome, greatly amplifies the potential and the applications of translational research in the oncology field. Moreover, the introduction of new experimental approaches, such as liquid biopsy, as well as new-concept clinical trials, such as biomarker-driven adaptive studies, may represent a turning point for BC translational research. It is likely that translational research will have in the near future a significant impact on BC care, especially by giving us the possibility to dissect the complexity of tumor cell biology and develop new personalized treatment strategies.

Background: Colon cancer is the most common type of gastrointestinal cancer. Despite advances during the last two decades, the efficacy of colorectal cancer treatment is still insufficient and new anticancer agents are necessary. Methods: In our study, colon cancer cells derived from a primary tumor (SW480) and lymph node metastasis (SW620) from the same patient were used and compared. The effect of flubendazole (FLU) on cell adhesion and migration was monitored using the x-CELLigence Real-Time Cell Analysis system. Expressions of molecules involved in adhesion and migration were analyzed using RT-PCR and western blot. Furthermore, RNA silencing of nuclear factor-ΚB in SW620 cells was used to determine the involvement of the NF-ΚB p65 regulation pathway in FLU action. Results: FLU significantly suppressed the adhesion of SW480 cells and reduced the expression of adhesion markers (ICAM-1, αE-catenin; β-catenin; integrin α5 and β1). Moreover, a significant anti-migratory potential of FLU was manifested in the SW620 cells. In addition, FLU suppressed the phosphorylation of NF-ΚB p65 and potentiated the suppression of several metastatic markers (ICAM-1, EpCAM, integrin α5, β1, α-tubulin) caused by NF-ΚB p65 silencing. Conclusion: FLU has a significant anti-migratory effect in intestinal cancer cell SW480 and its lymph node metastatic cells SW620. FLU decreases the expression of some proteins involved in metastatic processes and inhibits activation of NF-ΚB p65.

Background: Triterpenoids are an important class of natural bioactive products present in many medicinal plants. Objective: The aim of present study is to investigate the antioxidant and anticarcinogenic potential of Oleanolic Acid (OA) and Ursolic Acid (UA) on B16 murine melanoma cell line isolated from Plumeria obtusa, free and loaded in a nanoemulsion (NEm) system. Methods: The nanoemulsion was characterized by dynamic light scattering, transmission electron microscopy. The viscosity was also evaluated. The antioxidant activity was determined by the reduction of 2,2-diphenyl-2- picrylhydrazyl (DPPH) free radical. In vitro proliferation studies were determined using the sulforhodamine-B method. Results: OA/UA natural mixture exhibited high percentage of inhibition of DPPH (86.06% and 85.12%, with and without irradiation). Percentages of inhibition higher than 85% in samples with and without ultraviolet irradiation were recorded when loaded in the NEm system. The natural mixture incorporated into the NEm showed cytotoxic activity from 2.9 μM, whereas the free compounds from 17.4 μM. Conclusion: We conclude that these pentacyclic triterpenes loaded in a NEm system could be considered as a new potential tool for further investigation as anticancer agents.

Aims: Oncology treatments aim at selective toxicity for tumor (compared to normal) cells, and chromone- coumarin hybrids have shown such activity. Methods: In this study, we test a novel series of synthetic chromone and coumarin derivatives (1–9) for cytotoxic activity against a panel of tumor cell lines (MCF-7, A549, HepG2, HTC-116, B16 and Caco-2) opposed to non-tumor cells (HEK-293t). Electrical impedance spectroscopy was used to monitor cell viability in real time. Results: Compound 8 showed the most potent activity, and it significantly diminished cancer cell proliferation and viability in different cell lines. It induced apoptosis in a dose-dependent manner, as shown by Western blot and flow cytometry. Conlcusion: Electrical impedance spectroscopy appears to be a convenient tool for in vitro cytotoxicity analysis, which could be useful for identifying drug effects and side effects during early phases of drug discovery and development.

Background: Lung cancer is the most prevalent cancer and a high fatality disease. Despite of all available therapeutic approaches, drug resistance of chemotherapy agents for patients remain as an obstacle. New drugs integrating immunotherapeutic and conventional cytotoxic effects is a powerful strategy for the treatment of cancer to overcome this limitation. Antineoplastic phospholipids combine both of these activities by affecting lipid metabolism and signaling through lipid rafts. Therefore, they emerge as interesting scaffolds for designing new drugs. Objective: We aimed to evaluate antineoplastic phospholipids as scaffolds for designing new drugs for lung cancer treatment. Methods: The initial screening in A549 cells was performed by MTT assay. Others cytotoxic effects were evaluated in A549 cells by clonogenic assay, Matrigel 3D culture and flow cytometry analyses of cell cycle, apoptosis, mitochondrial membrane electronic potential and superoxide production. Immunological effects of ED were accessed on dendritic cells (DCs) and the expression of some markers were evaluated by flow cytometry. In vivo lung colonization analysis was performed after intravenously injection of A549 cells and daily treatment with ED. Results: Herein, ED showed to be the most efficient compound concerning cytotoxic, thereby, ED was selected for following tests. ED showed a cytotoxic profile in both monolayer and 3D culture and also in vivo models using A549 cells. This profile is due to G0/G1 phase cellular arrest and apoptosis drove by mitochondrial membrane depolarization and superoxide overproduction. Moreover, ED modulated DCs toward an activated pattern by the increased expression of CD83 and a remarkable decreased expression of PD-L1/CD274 on DCs membrane. Conclusions: Thus, ED is an interesting antitumor drug prototype due to not only its direct cellular cytotoxicity but also given its immunological features.

Background: Retinoblastoma is the most common intraocular malignant tumor in childhood. Although external beam radiation and enucleation are effective to control retinoblastoma, eye salvage and vision preservation are still significant challenges. Polyphyllin I (PPI), a natural compound extracted from Paris polyphylla rhizomes, has a wide range of activities against many types of cancers. However, the potential effect of this herbal compound on retinoblastoma has not yet been investigated. Method: In the present study, we evaluated the cytotoxic effect of PPI on human retinoblastoma Y-79 cells as well as its underlying molecular mechanism. Our results indicated that PPI treatment significantly inhibited cell proliferation, arrested the cell cycle at G2/M phase and induced cell apoptosis of Y79 cells through the mitochondrial- dependent intrinsic pathway. Moreover, p53 is involved in PPI-induced cytotoxicity in human retinoblastoma Y-79 cells. Exposure to 10 μM PPI for 48 h dramatically induced the expression levels of p53, phosphorylated- p53 and acetylated-p53. Furthermore, blockade of p53 expression effectively attenuated PPI-induced cell cycle arrest and cell apoptosis in Y-79 cells. Result: These results demonstrated that PPI exhibits anti-proliferation effect on human retinoblastoma Y-79 cells through modulating p53 expression, stabilization and activation. This information shed light on the potential application of PPI in retinoblastoma therapy.

Background and Purpose: It has been well-known both gold nanoparticles (AuNPs) and cisplatin are potential radiosensitizers for radiotherapy of cancer. In this in vitro study, we investigated the chemoradiotherapeutic effects of alginate nanogel co-loaded with AuNPs and cisplatin (ACA) on U87-MG human glioblastoma cells. Methods: Based on the accomplished pilot studies, U87-MG cells were incubated with ACA and cisplatin at 10% inhibitory concentration (IC10) for 4h. Then, the cells were irradiated to different doses of 6MV X-rays (2 and 10 Gy). MTT assay was performed to evaluate the cell survival rate. Apoptosis was determined by flow cytometry using an annexinV–fluorescein isothiocyanate/propidium iodide apoptosis detection kit. Results: The results showed that ACA at the concentration of 4 μg/ml (per cisplatin) and free cisplatin at concentration of 15 μg/ml have the same effects on U87-MG cells (survival rate: 90%). The combination of ACA with radiation resulted in a significant decrease in cell viability (survival rate: 30%). The flow cytometry assay also showed that such a combination therapy induces more apoptosis than necrosis. Conclusion: It may be concluded that co-delivery of AuNPs and cisplatin with a single nanoplatform like ACA nanocomplex enhances the therapeutic ratio of human glioblastoma radiation therapy.

Background: Phosphatidylinositol-3-kinase α (PI3Kα) is a ubiquitous intracellular enzyme, mainly involved in intracellular signaling pathways, promotes cellular growth, proliferation, and differentiation. Therefore, inhibition of PI3K can be a hotspot in molecular targeted therapy for the treatment of cancer. Methods: The present research work involves molecular docking studies performed to screen derivatives of urea and thiourea bearing thieno [3,2-d]-pyrimidines against the active site of PI3K enzyme using MOE.2008.10. The designed structures (6a-f) and (7a-j) were synthesized by the facile synthetic methods and evaluated for their anticancer activity against HT-29 and MCF-7 cell lines and inhibitory activity against PI3Kα enzyme. Results: Among the tested compounds, 4-(4-(2-(3-(pyrimidin-2-yl)thioureido)ethyl)piperazin-1-yl)thieno[3,2- d]pyrimidine-6-carboxamide (7f) showed the highest anticancer activity against HT-29 and MCF-7 cell lines with IC50 values of 2.18 μM and 4.25 μM, respectively. Further, the same compound also exhibited potent PI3Kα inhibitory activity with IC50 value of 1.26 μM. Conclusion: Docking studies supported the initial pharmacophoric hypothesis and suggested a mode of interaction at the active binding site of PI3Kα, demonstrating that the target compounds were potential inhibitory agents for cancer therapy.

Background#154;There are inconsistent reports about the role of Nitric Oxide (NO) in cancer progression and prevention. Quinones demonstrate significant anti-cancer activities both in vitro and in vivo. Objective#154; We investigated the effect of 2-methoxy-6-acetyl-7-methyljuglone (MAM), a natural naphthoquinone isolated from Polygonum cuspidatum Sieb. et Zucc, on NO generation and its role in DNA damage in cancer cells. Methods: BEL-7402 and A549 cells were cultured and treated with MAM. The NO generation, DNA damage, and protein expression were determined. Results: MAM induced inducible nitric oxide synthase (iNOS)/NO-mediated DNA damage response through activation of MAPKs pathways. MAM induced DNA damage by activating ATM/Chk2. MAM increased iNOS expression, NO production, and MAPKs (JNK1/2, ERK1/2, and p38MAPK) phosphorylation in concentrationand time- dependent manners. Furthermore, iNOS inhibitor 1400W, iNOS siRNA, and NO scavenger hemoglobin (Hb) could significantly reverse MAM-induced DNA damage, ATM/Chk2 activation, NO production, and cell death. In addition, MAPKs inhibitors (SP600125, U0126, and SB203580) reversed MAM-induced cell death and ATM/Chk2 activation. MAM-induced cell death was partially reversed by 1400W and Hb but enhanced by L-arginine. Conclusion: These results suggested that MAM induced iNOS/NO activation and generation mediated by MAPKs pathways, which resulted in DNA damage.

Background: 1,3,4-Oxadiazoles have been known with a wide variety of pharmacological activities including anticancer activity. Objective: In this study, novel 2,5-disubstituted 1,3,4-oxadiazole derivatives were synthesized and evaluated for determining their anticancer, anticholinesterase and lipoxygenase (LOX) inhibitory activity. Methods: All compounds were tested against C6 rat glioma, A549 human lung carcinoma and NIH/3T3 mouse embryo fibroblast cell lines to define cytotoxic concentrations and apoptosis induction levels which they cause. Results: Many of the compounds exhibited remarkable potency that compounds 2a, 2b, 2e, 2h and 2j against C6 cells and compounds 2a, 2b, 2d, 2g, 2i, 2j against A549 cells were found more active than cisplatin. Compound 2d namely, 2-[(5-(4-aminophenyl)-1,3,4-oxadiazol-2-yl)thio]-1-(4-chlorophenyl)ethan-1-one induced apoptosis of A549 cells with 74.9% whereas cisplatin caused 70.9% percentage. Conclusion: Among them, compounds 2d and 2j against A549 cell line, compounds 2b and 2e against both tumor cell lines showed selective cytotoxicity evaluating the inhibition concentration against NIH/3T3 cell line. None of the compounds showed significant acetylcholinesterase (AChE) and lipoxygenase inhibitory activities.