scholarly journals Organometallic iron complexes as potential cancer therapeutics.

2014 ◽  
Vol 61 (4) ◽  
Author(s):  
Gabriela Mojžišová ◽  
Ján Mojžiš ◽  
Janka Vašková

Metal-containing drugs have long been used for medicinal purposes in more or less empirical way. The potential of these anticancer agents has only been fully realised and explored since the discovery of the biological activity of cisplatin. Cisplatin and carboplatin have been two of the most successful anti-cancer agents ever developed, and are currently used to treat ovarian, lung and testicular cancers. They share certain side effects, so their clinical use is severely limited by dose-limiting toxicity. Inherent or acquired resistance is a second problem often associated with platinum-based drugs, with further limits of their clinical use. These problems have prompted chemists to employ different strategies in development of the new metal-based anticancer agents with different mechanisms of action. There are various metal complexes still under development and investigation for the future cancer treatment use. In the search for novel bio-organometallic molecules, iron containing anti-tumoral agents are enjoying an increasing interest and appear very promising as the potential drug candidates. Iron, as an essential cofactor in a number of enzymes and physiological processes, may be less toxic than non essential metals, such as platinum. Up to now, some of iron complexes have been tested as cytotoxic agents and found to be endowed with an antitumor activity in several in vitro tests (on cultured cancer cell lines) and few in vivo experiments (e. g. on Ehrlich's ascites carcinoma). Although the precise molecular mechanism is yet to be defined, a number of observations suggest that the reactive oxygen species can play important role in iron-induced cytotoxicty. This review covers some relevant examples of research on the novel iron complexes.

2021 ◽  
Vol 1 (1) ◽  
pp. 28-37
Author(s):  
Alexandra Dragoi ◽  
Oana Alexandru

Cancer chemotherapeutic drugs acts in different manner to kill malignant cells. Most of the anticancer drugs available in clinical practice to treat cancer patients, are natural products including whole plant extract, crude plant extracts, isolated constituents, plant –based drug formulations etc. These natural compounds have been a basis for the development of several drugs against cancer. Agents such as topotecan, taxol, vinca alkaloids (vincristine, vinblastine, vinorelbine and vindesine), are important anticancer agents in widespread clinical use. Other agents, such as combretastatin, flavopiridol, betulinic acid were shown to have anti-tumor effects in both in vitro and in vivo experiments. In this review, we aim to make a brief description of classical plant-derived chemotherapeutics drugs and also to highlight the importance of these natural compounds in the development of new potential drugs in cancer treatment.


1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.


1963 ◽  
Vol 10 (01) ◽  
pp. 106-119 ◽  
Author(s):  
E Beck ◽  
R Schmutzler ◽  
F Duckert ◽  

SummaryInhibitor of kallikrein and trypsin (KI) extracted from bovine parotis was compared with ε-aminocaproic acid (EACA): both substances inhibit fibrinolysis induced with streptokinase. EACA is a strong inhibitor of fibrinolysis in concentrations higher than 0, 1 mg per ml plasma. The same amount and higher concentrations are not able to inhibit completely the proteolytic-side reactions of fibrinolysis (fibrinogenolysis, diminution of factor V, rise of fibrin-polymerization-inhibitors). KI inhibits well proteolysis of plasma components in concentrations higher than 2,5 units per ml plasma. Much higher amounts of KI are needed to inhibit fibrinolysis as demonstrated by our in vivo and in vitro tests.Combination of the two substances for clinical use is suggested. Therapeutic possibilities are discussed.


2008 ◽  
Vol 53 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Rahul P. Bakshi ◽  
Dongpei Sang ◽  
Andrew Morrell ◽  
Mark Cushman ◽  
Theresa A. Shapiro

ABSTRACT African trypanosomiasis (sleeping sickness), caused by protozoan Trypanosoma brucei species, is a debilitating disease that is lethal if untreated. Available drugs are antiquated, toxic, and compromised by emerging resistance. The indenoisoquinolines are a class of noncamptothecin topoisomerase IB poisons that are under development as anticancer agents. We tested a variety of indenoisoquinolines for their ability to kill T. brucei. Indenoisoquinolines proved trypanocidal at submicromolar concentrations in vitro. Structure-activity analysis yielded motifs that enhanced potency, including alkylamino substitutions on N-6, methoxy groups on C-2 and C-3, and a methylenedioxy bridge between C-8 and C-9. Detailed analysis of eight water-soluble indenoisoquinolines demonstrated that in trypanosomes the compounds inhibited DNA synthesis and acted as topoisomerase poisons. Testing these compounds on L1210 mouse leukemia cells revealed that all eight were more effective against trypanosomes than against mammalian cells. In preliminary in vivo experiments one compound delayed parasitemia and extended survival in mice subjected to a lethal trypanosome challenge. The indenoisoquinolines provide a promising lead for the development of drugs against sleeping sickness.


2021 ◽  
Vol 24 (2) ◽  
pp. 167-175
Author(s):  
E. I. Firkova

Periodontal research has developed very fast in the last two decades. Although at this stage of science a lot of genetic and molecular-based trials are performed in order to elucidate the complex etiology, pathophysiology, biofilm-host interactions and responses on genetic and cellular level, in vivo animal models are still used. In many ways, in vivo experiments are superior to in vitro tests when the dynamics of the immune-inflammatory nature of the periodontal disease and peri-implantitis and the specific healing of soft and hard tissues is concerned. Screening the efficacy, mechanisms of action and application of different biomaterials requires in vivo experiments, be-fore the data translation to clinical settings. A number of small animals like rodents and large species like dogs and nonhuman primates are involved in periodontal research. As live creatures are used, the design of the studies must be well defined, with regard to the type of the animals, most suitable for the tested hypothesis, observation period, sample size, study power, critical size defects, and specific testing sites.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4756-4756 ◽  
Author(s):  
Gwyn Bebb ◽  
Huong Muzik ◽  
Sophia Nguyen ◽  
Don Morris ◽  
Douglas A. Stewart

Abstract Introduction Mantle cell lymphoma (MCL), an incurable B cell lymphoma, consistently over expresses bcl-2 despite not carrying the t(14;18). The attenuation of apoptosis by bcl-2 is thought to contribute to the malignant process and increase resistance to some cytotoxic agents. We recently demonstrated that GX15-070, a small molecular inhibitor of the BH3 binding groove of bcl-2, has activity against MCL cell lines in vitro. We set out to assess the effect of GX15-070 alone and in combination with Vincristine on the viability of MCL cells in vitro and in vivo. Methods 3 previously characterized bcl-2 over expressing MCL cell lines (JVM-2, Hbl-2, granta) were used. Cells were grown in standard media and exposed to a range of concentrations of GX15-070 with and without Vincristine. Dose-response was assessed by measuring viability at 48 hours using the WST-1 assay. In vivo experiments were conducted on immune deficient mice in which 5×106 cells were injected in the flank then treated IV with GX15-070 (q 2days × 5 doses), Vincristine (q4 days × 3 doses) or both starting 5 days later. Tumours were measured three times weekly. Results All three MCL cell lines over-expressed bcl-2 by western blot. Each MCL cell line showed sensitivity to GX15-070 at a range of concentrations. The addition of GX15-070 to low dose Vincristine (10−6) caused significant growth inhibition of each MCL cell line (see table 1). Discussion Our results demonstrate that using GX15-070 to target bcl-2 is an effective anti neoplastic approach against MCL cell lines in vitro. In addition, our results suggest that combining Vincristine and GX15-070 is a promising strategy in treating MCL. In vivo experiments to confirm this additive activity are still ongoing and will be presented in full. Initial impressions suggest that there is a rationale for the addition of GX15-070 to current cytotoxic regimens used to treat MCL in the setting of clinical trials. Table 1: Effect of Vincristine and GX15-070 on in vitro growth of 3 MCL cell lines Growth as % age of Control Cell Line JVM-2 HBL-2 Granta Vincristine alone (10-6 mg/ml) 92% 48% 89% GX15-070 alone (0.08 uM) 75% 76% 60% Vincristine 10-6 mg/ml and GX15-070 0.08 uM 52% 24% 52%


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13509-e13509
Author(s):  
Roberto Bianco ◽  
Roberta Rosa ◽  
Lucia Nappi ◽  
Luigi Formisano ◽  
Vincenzo Damiano ◽  
...  

e13509 Background: Although EGFR inhibitors, such as the mAb cetuximab, represent an effective strategy in colorectal cancer (CRC), the clinical use of these agents is limited by intrinsic or acquired resistance. Alterations in the ‘sphingolipid rheostat’, or the balance between the proapoptotic molecule ceramide and the mitogenic factor sphingosine-1-phosphate (S1P), due to overactivation of sphingosine kinase 1 (SphK1), have been involved in the regulation of resistance to anticancer agents. Since some studies described cross-talks between SphK1 and EGFR-dependent signalling pathways, we investigated the contribution of SphK1 to cetuximab resistance in CRC models. Methods: We used CRC cell lines with both intrinsic or acquired resistance to cetuximab. In these models, we analyzed SphK1 expression/activation by using different tools, including the available drug fingolimod (FTY720), both in vitro and in vivo. We confirmed our data through a tissue microarray (TMA)-based analysis on CRC tissues. Results: SphK1 is overexpressed in CRC cells resistant to cetuximab. Higher doses of N,N-dimethylsphingosine (DMS), a potent competitive inhibitor of SphK1, are needed to achieve complete enzyme saturation and survival inhibition in resistant cells. Moreover, ceramide induces apoptosis less efficiently in resistant than in sensitive cells, consistently with the idea that increased SphK1 levels mediate S1P synthesis by ceramide in resistant cells. SphK1 contribution to resistance is supported by the demonstration that SphK1 inhibition by DMS or silencing via siRNA in resistant cells restores sensitivity to cetuximab, whereas exogenous SphK1 overexpression in wild-type cells confers resistance. Re-sensitization to cetuximab is observed after treatment with fingolimod, a S1P receptor inhibitor, both in vitro and in nude mice xenografted with CRC cells. Finally, a TMA-based analysis on CRC tissues revealed that SphK1 expression is related to K-Ras mutational status, a well-known determinant of cetuximab resistance. Conclusions: Our data could clarify the role of SphK1 in the onset of resistance to cetuximab, thus suggesting SphK1 inhibition as a part of novel targeting strategies for resistant cancer patients.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Junjie Xu ◽  
Zhe Wan ◽  
Minyue Tang ◽  
Zhongjie Lin ◽  
Shi Jiang ◽  
...  

Abstract Background and aims Accumulating evidence suggests that the primary and acquired resistance of hepatocellular carcinoma (HCC) to sorafenib is mediated by multiple molecular, cellular, and microenvironmental mechanisms. Understanding these mechanisms will enhance the likelihood of effective sorafenib therapy. Methods In vitro and in vivo experiments were performed and clinical samples and online databases were acquired for clinical investigation. Results In this study, we found that a circular RNA, circRNA-SORE, which is up-regulated in sorafenib-resistant HCC cells, was necessary for the maintenance of sorafenib resistance, and that silencing circRNA-SORE substantially increased the efficacy of sorafenib-induced apoptosis. Mechanistic studies determined that circRNA-SORE sequestered miR-103a-2-5p and miR-660-3p by acting as a microRNA sponge, thereby competitively activating the Wnt/β-catenin pathway and inducing sorafenib resistance. The increased level of circRNA-SORE in sorafenib-resistant cells resulted from increased RNA stability. This was caused by an increased level of N6-methyladenosine (m6A) at a specific adenosine in circRNA-SORE. In vivo delivery of circRNA-SORE interfering RNA by local short hairpin RNA lentivirus injection substantially enhanced sorafenib efficacy in animal models. Conclusions This work indicates a novel mechanism for maintaining sorafenib resistance and is a proof-of-concept study for targeting circRNA-SORE in sorafenib-treated HCC patients as a novel pharmaceutical intervention for advanced HCC.


2020 ◽  
Vol 1 (5) ◽  
pp. 192-200
Author(s):  
Madhulika Srikanth ◽  
Waseem S Khan ◽  
Ramazan Asmatulu ◽  
Heath E Misak ◽  
Shang-You Yang ◽  
...  

The unique structures and properties of nanomaterials have attracted many engineers and scientists to these resources for different applications, including biomedical, electronics, manufacturing, transportation, energy, and defense. The increasing applications of nanomaterials have also caused some concern among the scientific community about their safety and cytotoxicity. To successfully use nanomaterials in different fields, their interaction with mammalian cells in vitro must be addressed before in vivo experiments can be carried out successfully. In this study, the cytotoxicity values of commonly known nanomaterials, such as 100-ply Carbon Nanotube (CNT) wires, graphene, CNTs, nanoclay, and fullerene, were investigated through in vitro tests on human L929 and mice 3T3 fibroblast cells and compared with each other. The effects of cytotoxicity on both cell types were similar in many ways, but not closely identical due to structural and morphological differences. Compared to mice fibroblast cells, human fibroblast cells have a larger surface area; therefore, the viability values of L929 cells at different dilutions and time durations vary over a larger range. Pristine 100-ply CNT wires were found to be the least cytotoxic, with an average viability of 86.9%, whereas materials with high aspect ratio (e.g., CNTs and graphene) had higher cytotoxicity values due to their potential to pierce through cell membranes.


2020 ◽  
Vol 9 (8) ◽  
pp. 2342
Author(s):  
Eiji Hishinuma ◽  
Evelyn Gutiérrez Rico ◽  
Masahiro Hiratsuka

Fluoropyrimidine drugs (FPs), including 5-fluorouracil, tegafur, capecitabine, and doxifluridine, are among the most widely used anticancer agents in the treatment of solid tumors. However, severe toxicity occurs in approximately 30% of patients following FP administration, emphasizing the importance of predicting the risk of acute toxicity before treatment. Three metabolic enzymes, dihydropyrimidine dehydrogenase (DPD), dihydropyrimidinase (DHP), and β-ureidopropionase (β-UP), degrade FPs; hence, deficiencies in these enzymes, arising from genetic polymorphisms, are involved in severe FP-related toxicity, although the effect of these polymorphisms on in vivo enzymatic activity has not been clarified. Furthermore, the clinical usefulness of current methods for predicting in vivo activity, such as pyrimidine concentrations in blood or urine, is unknown. In vitro tests have been established as advantageous for predicting the in vivo activity of enzyme variants. This is due to several studies that evaluated FP activities after enzyme metabolism using transient expression systems in Escherichia coli or mammalian cells; however, there are no comparative reports of these results. Thus, in this review, we summarized the results of in vitro analyses involving DPD, DHP, and β-UP in an attempt to encourage further comparative studies using these drug types and to aid in the elucidation of their underlying mechanisms.


Sign in / Sign up

Export Citation Format

Share Document