Dose Issues in Cancer Chemotherapy

Electrochemical detection of the oxidative damage of a potential pyrimido[5,4-g]pteridine-derived antitumor agent toward DNA

In this work, we design and synthesize 2,2'-(7,9-dimethyl-2,4,6,8-tetraoxo-6,7,8,9-tetrahydropyrimido[5,4-g]pteridine-1,3(2H,4H)-diyl)bis(N,N-bis(2-chloroethyl)acetamide) (PT-MCA) as a novel DNA intercalator and potential antitumor agent. Electrochemical analysis reveals the redox process of PT-MCA on the electrode surface. The bioelectrochemical sensors are obtained by modifying the surface of GCE with calf thymus DNA (ctDNA), poly (dG), poly (dA), and G-quadruplex, respectively. The DNA oxidative damage induced by PT-MCA is investigated by comparing the peak intensity change of dGuo and dAdo and monitoring the peaks of the oxidation products of guanine and/or adenine (8-oxoGua and/or 2,8-oxoAde). UV-vis absorption and fluorescence spectra and gel electrophoresis are further employed to understand the intercalation of PT-MCA into DNA base pairs. Moreover, PT-MCA is proved to exhibit stronger anti-proliferation activity than mitoxantrone against both 4T1 and B16-F10 cancer cells. At last, the oxidative damage of PT-MCA toward ctDNA is not interfered by the coexistence of ions and also can be detected in real serums.

Target concentration achievement for efficacy and safety of patients with osteosarcoma treated with high-dose methotrexate based on individual pharmacokinetics: A retrospective study

In the high-dose methotrexate (HD-MTX) treatment of patients with osteosarcoma, a dose-adjustment method using individual pharmacokinetic parameters (PK method) to optimize the concentration was developed in 2010. However, to the best of our knowledge, the clinical usefulness of the PK method has not been verified until now. In the present retrospective study, to assess the usefulness of the PK method, the achievement rate of an effective and safe concentration range was evaluated. A total of 43 patients with osteosarcoma who were administered HD-MTX therapy (43 first courses and 200 subsequent courses) were enrolled. The MTX dose in the first course was determined using a common method based on body surface area (BSA method); a total of 8-12 g/m² was administered as an initial dose for 1 h and a maintenance dose for 5 h. In the subsequent courses, loading and maintenance doses were calculated by the PK method based on the serum MTX concentration profile of the previous course. The effective target concentration during 1-6 h after the start of MTX administration was 700-1,000 µmol/l, whereas the target safe MTX level was less than 10, 1 and 0.1 µmol/l at 24, 48 and 72 h, respectively. Notably, the rate of achieving the effective target concentration was significantly higher when using the PK method as compared to that when using the BSA method. The achievement rate of the safe target concentration at 24, 48 and 72 h when using the PK method was significantly higher. Additionally, the incidence of abnormal laboratory values of aspartate aminotransferase and alanine aminotransferase was significantly lower when using the PK method. Therefore, the PK method was suggested to be very useful in HD-MTX therapy for patients with osteosarcoma.

Targeting co-delivery of doxorubicin and gefitinib by biotinylated Au NCs for overcoming multidrug resistance in imaging-guided anticancer therapy

Drug resistance and potential cardiotoxicity severely limit the DOX-mediated chemotherapy in clinical. Multi-drug combination is conducive to the realization of multi-modal synergy at the molecular level, which is crucial in drug dose optimization and improvement of therapeutic effect. In this work, fluorescent biotinylated Au Nanoclusters as an active targeting carrier was developed to realize real-time biological imaging and dual-drug delivery simultaneously. DNA toxin doxorubicin (DOX) and tyrosinase inhibitor gefitinib (GEF) were selected as dual-drug models for the treatment of human non-small cell lung cancer. The in vitro and in vivo results showed that dual-drug combination suppressed cancer cell growth more efficiently than any single formula at the same concentrations. GEF can block signaling in target cancer cells with mutated and overactive EGFR, thereby inhibiting tumor growth and metastasis and promoting tumor cell apoptosis. Combined with DOX chemotherapy, it will effectively overcome the problem of DOX resistance. In addition, the dual-drug delivery system produced excellent synergistic therapeutic effects without extra adverse toxicities. It provides a reference for the design and clinical application of the dual-drug delivery system.

Oncolytic Adenoviruses: Strategies for Improved Targeting and Specificity

Cancer is a major health problem. Most of the treatments exhibit systemic toxicity, as they are not targeted or specific to cancerous cells and tumors. Adenoviruses are very promising gene delivery vectors and have immense potential to deliver targeted therapy. Here, we review a wide range of strategies that have been tried, tested, and demonstrated to enhance the specificity of oncolytic viruses towards specific cancer cells. A combination of these strategies and other conventional therapies may be more effective than any of those strategies alone.