A functionalized graphene oxide with improved cytocompatibility for stimuli-responsive co-delivery of curcumin and doxorubicin in cancer treatment.

Nowadays, the usage of nanoparticles in various fields such as drug delivery, attracts the attention of many researchers in the treatment of cancers. Graphene oxide (GO) is one of the novel drug delivery systems which is used broadly owing to its unique features. In this survey, doxorubicin (DOX) was accompanied by natural medicine, curcumin (CUR), to diminish its side effects and enhance its efficiency. Cytotoxicity assay in human gastric cancer (AGS), prostate cancer (PC3), and ovarian cancer (A2780), was evaluated. Also, the uptake of DOX and CUR into cells, was assessed using a fluorescence microscope. Moreover, real-time PCR was applied for the evaluation of the expression of RB1 and CDK2 genes, which were involved in the cell cycle. In both separate and simultaneous forms, DOX and CUR were loaded with high efficiency and the release behavior of both drugs was pH-sensitive. The higher release rate was attained at pH 5.5 and 42 °C for DOX (80.23%) and CUR (13.06), respectively. The intensity of fluorescence in the free form of the drugs, was higher than the loaded form. In the same concentration, the free form of CUR and DOX were more toxic than the loaded form in all cell lines. Also, free drugs showed more impact on the expression of RB1 and CDK2 genes. Co-delivery of CUR and DOX into the mentioned cell lines, was more effective than the free form of CUR and DOX due to its lower toxicity to normal cells.

Plant Polyphenolic Compounds Potentiates Therapeutic Efficiency of Anticancer Chemotherapeutic Drugs: A Review.

BACKGROUND: Scientific research continues to develop more efficacious drugs to treat and cure cancer, the dreadful disease threatening the human race. Chemotherapy is an essential means in cancer therapy, however, plant drugs having pharmacological safety, can be used alone or as additions to current chemotherapeutic agents to enhance therapeutic efficacy and minimize chemotherapyinduced adverse effects. OBJECTIVE: A combination therapy where the synergistic effect on multiple targets is possible has gained significance because a one-drug one-target approach fails to yield the desired therapeutic effect. Therefore, a detailed description of important plant polyphenolic compounds with anticancer activity and their role in potentiating chemotherapeutic efficiency of existing anticancer drugs is provided in this review. Systematically screening combinations of active pharmaceutical ingredients for potential synergy with plant compounds may be especially valuable in cancer therapy. METHODS: We extensively have gone through reviews and research articles available in the literature. We made use of databases such as Google Scholar, Research Gate, PubMed, Science Direct, etc. The following keywords were used in our literature search: "Chemotherapy, drug development, cancer drugs, plant-derived polyphenolics, synergistic studies, combination therapy, diagnosis and genetics." CONCLUSION: Systematic research studies on screening combinations of plant phytochemicals with potential chemotherapeutic pharmaceuticals shed light on their synergistic effects, mechanisms of actions paving the way to develop more efficient anticancer therapeutics to treat and cure the cancer menace, to nullify chemotherapy-induced adverse effects and our review substantially contributes in this direction.

Shenmai injection suppresses multidrug resistance in MCF-7/ADR cells through the MAPK/NF-κB signalling pathway.

Context: Shenmai Injection (SMI) is usually used to treat atherosclerotic coronary heart disease and viral myocarditis in China. However, the effect of SMI on multidrug resistance has not been reported.Objective: To investigate the reversal effect of SMI in adriamycin (ADR) resistant breast cancer cell line (MCF-7/ADR) and explore the related molecular mechanisms.Materials and methods: The effect of SMI (0.25, 0.5, 1 mg/mL) to reverse chemoresistance in MCF-7/ADR cells was elucidated by MTT, HPLC-FLD, DAPI staining, flow cytometric analysis, western blotting. At the same time, in vivo test was conducted to probe into the effect of SMI on reversing ADR resistance, and verapamil (10 µM) was used as a positive control.Results: The results showed that the toxicity of ADR to MCF-7/ADR cells was strengthened significantly after treated with SMI (0.25, 0.5, 1 mg/mL), the IC50 of ADR was decreased 54.4-fold. The intracellular concentrations of ADR were increased 2.2-fold (p < 0.05) and ADR accumulation was enhanced in the nuclei (p < 0.05). SMI could strongly enhance the ADR-induced apoptosis and increase intracellular rhodamine 123 accumulation in MCF-7/ADR cells. Additionally, a combination of ADR and SMI (5 mg/kg) could dramatically reduce the weight and volume of tumour (p < 0.05). Furthermore, the results revealed that SMI might reverse MDR via inhibiting ADR-induced activation of the mitogen-activated protein kinase/nuclear factor (NF)-κB pathway to down-regulated the expression of P-glycoprotein (P-gp).Discussion and conclusions: SMI could potentially be used to treat ADR-resistance. This suggests possibilities for future clinical research.

Drug combination sensitivity scoring facilitates the discovery of synergistic and efficacious drug combinations in cancer.

High-throughput drug screening has facilitated the discovery of drug combinations in cancer. Many existing studies adopted a full matrix design, aiming for the characterization of drug pair effects for cancer cells. However, the full matrix design may be suboptimal as it requires a drug pair to be combined at multiple concentrations in a full factorial manner. Furthermore, many of the computational tools assess only the synergy but not the sensitivity of drug combinations, which might lead to false positive discoveries. We proposed a novel cross design to enable a more cost-effective and simultaneous testing of drug combination sensitivity and synergy. We developed a drug combination sensitivity score (CSS) to determine the sensitivity of a drug pair, and showed that the CSS is highly reproducible between the replicates and thus supported its usage as a robust metric. We further showed that CSS can be predicted using machine learning approaches which determined the top pharmaco-features to cluster cancer cell lines based on their drug combination sensitivity profiles. To assess the degree of drug interactions using the cross design, we developed an S synergy score based on the difference between the drug combination and the single drug dose-response curves. We showed that the S score is able to detect true synergistic and antagonistic drug combinations at an accuracy level comparable to that using the full matrix design. Taken together, we showed that the cross design coupled with the CSS sensitivity and S synergy scoring methods may provide a robust and accurate characterization of both drug combination sensitivity and synergy levels, with minimal experimental materials required. Our experimental-computational approach could be utilized as an efficient pipeline for improving the discovery rate in high-throughput drug combination screening, particularly for primary patient samples which are difficult to obtain.

Improved cytotoxicity of pyridyl-substituted thiosemicarbazones against MCF-7 when used as metal ionophores.

Zinc is the second most abundant transition metal in the human body, between 3 and 10% of human genes encoding for zinc binding proteins. We have investigated the interplay of reactive oxygen species and zinc homeostasis on the cytotoxicity of the thiosemicarbazone chelators against the MCF-7 cell line. The cytotoxicity of thiosemicarbazone chelators against MCF-7 can be improved through supplementation of ionic zinc provided the zinc ion is at a level exceeding the thiosemicarbazone concentration. Elimination of the entire cell population can be accomplished with this regime, unlike the plateau of cytotoxicity observed on thiosemicarbazone monotherapy. The cytotoxic effects of copper complexes of the thiosemicarbazone are not enhanced by zinc supplementation, displacement of copper from the complex being disfavoured. Treatment of MCF-7 with uncomplexed thiosemicarbazone initiates post G1 blockade alongside the induction of apoptosis, cell death being abrogated through subsequent supplementation with zinc ion after drug removal. This would implicate a metal depletion mechanism in the cytotoxic effect of the un-coordinated thiosemicarbazone. The metal complexes of the species, however, fail to initiate similar G1 blockade and apparently exert their cytotoxic effect through generation of reactive oxygen species, suggesting that multiple mechanisms of cytotoxicity can be associated with the thiosemicarbazones dependant on the level of metal ion association.

Curcuma increasing antitumor effect of Rhizoma paridis saponins through absorptive enhancement of paridis saponins.

Rhizoma paridis saponins (RPS) played a good antitumor role in many clinical applications. However, low oral bioavailability limited its application. In this research, water extract of Curcuma (CW) significantly increased antitumor effect of Rhizoma paridis saponins (RPS). GC-MS was used to identify its polar composition. HPLC was applied for determination of the content of curcuminoids in CW. As a result, 47 analytes with 0.65% of curcuminoids were identified in CW. According to the in vivo anti-tumor data, the best proportion of curcuminoids in CW with RPS was 16:500 (w/w). Using this ratio, curcuminoids significantly increased absorption of RPS in the everted rat duodenum sac system. In addition, curcuminoids decreased the promotion of RPS on rhodamine 123 efflux. The effect of curcuminoids was similar to that of the P-gp inhibitor, cyclosporin A in combination with RPS. In conclusion, drug combination of water extract of Curcuma with RPS was a good method to increase the antitumor effect of RPS. This combination would be a potent anticancer agent used in the prospective application.

S-1: a promising new oral fluoropyrimidine derivative.

S-1 is an oral fluoropyrimidine that is designed to improve the antitumor activity of 5-fluorouracil (5-FU) concomitantly with an intent to reduce its toxicity. S-1 consists of tegafur, a prodrug of 5-FU combined with two 5-FU biochemical modulators:5-chloro-2,4-dihydroxypyridine (gimeracil or CDHP), a competitive inhibitor of dihydropyrimidine dehydrogenase and oteracil potassium which inhibits phosphorylation of 5-FU in the gastrointestinal tract decreasing serious gastrointestinal toxicities,including nausea, vomiting, stomatitis and diarrhea. Being an oral agent, S-1 offers convenience of administration and prevents complications of central venous access such as infection, thrombosis and bleeding. S-1 has shown efficacy in both gastrointestinal as well non-gastrointestinal malignancies. The authors review the current literature and provide their expert opinion on the incorporation of S-1 in the treatment of solid malignancies [corrected].

Lymph node status and TS gene expression are prognostic markers in stage II/III rectal cancer after neoadjuvant fluorouracil-based chemoradiotherapy.

PURPOSE: According to the CAO/ARO/AIO-94 trial of the German Rectal Cancer Study Group, preoperative combined fluorouracil (FU) -based long-term chemoradiotherapy (CT/RT) is recommended for patients with International Union Against Cancer (UICC) stage II/III rectal cancer. However, despite the local benefit of neoadjuvant treatment, the overall prognostic value remains uncertain in comparison with adjuvant CT/RT. Furthermore, the prognostic value of molecular biomarkers, such as thymidylate synthase (TS), thymidine phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD), all of which are involved in the FU metabolism, is unknown in neoadjuvant settings. We assessed the impact of standardized preoperative CT/RT and intratumoral TS, TP, and DPD levels on patient outcome. PATIENTS AND METHODS: Forty patients with rectal cancer pretherapeutic UICC stage II/III, receiving preoperative FU-based CT/RT (CAO/ARO/AIO-94 trial) followed by standardized surgery, including total mesorectal excision, were investigated. Downsizing, downstaging, tumor regression, as well as TS, TP, and DPD gene expression of post-treatment surgical specimens were correlated with disease-free survival (DFS) and overall survival (OS). RESULTS: Significant downsizing (P < .001) and downstaging (P = .001) were achieved with preoperative CT/RT. During a median follow-up of 49 months (95% CI, 43 to 58 months), the cancer recurrence rate was 28.2%. DFS and OS were significantly increased in patients with downstaging (P < .001 and P = .003, respectively), compared with patients without downstaging. All patients who developed cancer recurrence had a persistent positive lymph node status after preoperative CT/RT (P < .001) and a significantly higher TS gene expression (P = .035) compared with those patients without recurrence. CONCLUSION: Persistent positive lymph node status and high intratumoral TS expression after preoperative CT/RT are predictive of an unfavorable prognosis in rectal cancer UICC stage II/III.

Efficacies of tea components on doxorubicin induced antitumor activity and reversal of multidrug resistance.

Considering of novel biochemical modulation by some foods and beverages, we have performed screening for green tea components that have enhancing effects on doxorubicin (DOX) induced antitumor activity. Components, such as caffeine, theanine, (-)-epigallocatechin gallate (EGCG) and flavonoids have inhibitory effects on the DOX efflux from Ehrlich ascites carcinoma cells. Thus, it is suggested that EGCG and flavonoids may enhance DOX induced antitumor activity and increase the DOX concentrations in tumors through the inhibition of DOX efflux. It is expected that these components in green tea exhibit low toxicity and that there are few side effects of drinking green tea in combination with an antitumor agent. We think that the intake of a favorite beverage favors a positive mental attitude of a patient and increases the efficacy of the chemotherapeutic index, and that this efficacy is useful for improving the quality of life on cancer chemotherapy. In DOX resistant P388 leukemia cell bearing mice theanine increased the DOX induced efficacy through an increase in the DOX concentrations in the tumors. Theanine attacked the same transport process for DOX in both types of cells, elevated the DOX concentration and increased the DOX induced antitumor activity.

Pharmacokinetics and pharmacodynamics of high-dose zidovudine administered as a continuous infusion in patients with cancer.

STUDY OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of high-dose intravenous zidovudine (ZDV). DESIGN: Phase 1, dose-escalating, unblinded study in patients with cancer. SETTING: A university-affiliated cancer treatment center. PATIENTS: Fourteen patients (6 women) with solid tumors that were unresponsive to standard therapy received 31 courses of therapy. INTERVENTIONS: Intravenous ZDV was administered in doses of 2, 3, 4, 5.5, 7, 8.5, 10, 12, 15, or 20 g/m2/day as a continuous infusion over 48 hours. Patients also received fluorouracil plus leucovorin for 24 hours before the start of and during the ZDV infusion. If no dose-limiting toxicities were encountered, subsequent doses were escalated. Blood samples were collected at 24 and 48 hours after the start of the infusion, and hourly for 4 hours after stopping the infusion. Urine was collected in five patients during the infusion and for 24 hours after stopping it. Blood for measuring peripheral white blood cells was collected before and at the end of the infusion in seven patients to measure DNA chain breaks due to incorporation of ZDV. MEASUREMENTS AND MAIN RESULTS: Zidovudine was measured in plasma by high-performance liquid chromatography and in urine fluorescence polarization immunoassay. Its incorporation into DNA was measured by determining DNA strand breakage in peripheral white blood cells using fluorescence analysis. Pharmacokinetic models were fit to plasma ZDV concentrations using extended least squares regression. Short-term high-dose ZDV was generally well tolerated, with adverse effects related to large amounts of free water administered during the infusion. The mean (SD) ZDV pharmacokinetic values were total clearance 1.44 (1.09) L/hr/kg, volume of distribution 2.72 (2.97) L/kg, and half-life 1.2 (0.6) hours. There was considerable interpatient variability in total drug clearance. Although ZDV exposure increased proportionately with increasing dose, two of three patients receiving the highest dose (20 g/m2/day) had markedly low total drug clearances. The relation between the percentage of abnormal DNA in peripheral white blood cells and zidovudine area under the plasma ZDV versus time curve was described by the Emax pharmacodynamic model. CONCLUSIONS: The pharmacokinetics of high-dose ZDV administered by continuous infusion to patients with cancer are similar to those reported with lower doses in patients with infection due to the human immunodeficiency virus. Further study of potential nonlinear pharmacokinetic behavior at doses above 20 g/m2/day is necessary. The high between-patient variability in ZDV clearance results in variable levels of exposure in vivo, and indicates the need for concentration- or effect-controlled study designs in the further evaluation of the agent's antineoplastic effects.

Pharmacokinetic characteristics of 5-fluorouracil and mitomycin C in intraperitoneal chemotherapy.

Eight patients with malignancies confined to the peritoneal space participated in this study. Five hundred milligrams 5-fluorouracil or 10 mg mitomycin C was diluted in 1 L saline. The mixed solution was injected intraperitoneally through the semi-permanent peritoneal catheter. Blood and peritoneal fluid were collected after injection. 5-Fluorouracil concentrations in the peritoneal fluid were 1000 times those in serum, while mitomycin C concentrations were 100 times those in serum. Areas under the concentration vs time curve (AUC) were calculated by the trapezoidal method with extrapolation to infinity. The ratio of peritoneal fluid AUC to serum AUC was about 1400 for 5-fluorouracil and 80 for mitomycin C. Patterns for the absorption and elimination from systemic circulation were similar for both compounds. Drug concentrations in the peritoneal fluid and serum were analysed according to the compartment model. The half-life in the peritoneal fluid (t1/2p) and the rate constant from the peritoneal fluid to the systemic circulation (ka) were nearly equal for both 5-fluorouracil and mitomycin C (t1/2p, 1.0 h for 5-fluorouracil and 1.3 h for mitomycin C; ka 0.71 h-1 for 5-fluorouracil and 0.68 h-1 for mitomycin C), although the apparent volume of distribution (Vds/F) and clearance in the peritoneal cavity (CLp) for mitomycin C (78 L m-2 and 1.8 L h-1 m-2) were about twice the values for 5-fluorouracil (149 L m-2 and 0.8 L h-1 m-2).

Interactions between 7-hydroxymethotrexate and folinic acid in RAJI cells, in vitro.

HPLC analysis of plasma samples obtained from patients included in a high-dose methotrexate-folinic acid Rescue (HD-MTX-CF) protocol, allowed the simultaneous determination of MTX, CF and their respective plasma metabolites, 7-hydroxymethotrexate (7-OH-MTX) and 5-methyltetrahydrofolate (5-CH3-FH4). These 4 compounds interact at the cellular level to ensure the selective effectiveness of the HD-MTX-CF rescue protocol. An in vitro study has been investigated in RAJI cells to better describe the interference of CF on uptake, accumulation and metabolism of [3H]7-OH-MTX. Results about uptake and accumulation of CF were also obtained using [3H]CF, in the absence or the presence of unlabeled 7-OH-MTX. The rate of [3H]7-OH-MTX influx in RAJI cells (Km = 25.30 +/- 7.75 microM, n = 3) was competitively inhibited by the presence of 10 microM CF with a Ki value of 6.00 +/- 1.94 microM (n = 2). Intracellular 7-OH-MTX accumulation was decreased by approximately 30% when extracellular CF concentration was twice as high as that of 7-OH-MTX, and 70% when CF extracellular concentration was 5 times higher. The metabolism of 7-OH-MTX to its intracellular polyglutamyl derivatives was depressed by 90% when 10 microM CF were incubated for 2 h with equimolar [3H]7-OH-MTX, and it was completely abolished in the presence of 100 microM CF.

High-dose chemotherapy. Concepts and strategies.

In experimental tumors, a steep dose-response curve has been demonstrated for chemosensitive malignancies. In clinical practice, increasing dose over the conventional dose results in higher responses. These observations have prompted efforts to use chemotherapy in higher doses. Initial empiricism lends itself to more rational use of high-dose chemotherapy. Strategies are based on alteration in drug schedules [e.g., high-dose cytosine arabinoside (Ara-C)], drug-to-drug interaction [e.g., high-dose methotrexate (MTX) with citrovorum rescue], and drug pharmacokinetics (e.g., regional chemotherapy). In general, increasing the dose of cytotoxic agents leads to increasing toxicity. Methods to circumvent unacceptable toxicity have been explored. Autologous bone marrow transplant is one such method that provides new avenues of therapy and has resulted in the emergence of a new spectrum of dose-limiting toxicity. Despite the improved response rate, high-dose chemotherapy has resulted in short response durations and no significant impact on the survival of cancer patients as yet. The greater benefit of such a modality may be in the consolidation of drug-sensitive tumors (e.g., lymphoma and small cell carcinoma) with minimal residual disease after minimal conventional therapy. We review various factors and concepts as they relate to the current use of high-dose chemotherapy. We conclude that drug resistance is multifactorial, and one variable that can be manipulated by clinicians is drug dose. The drug concentration appears crucial in enhancing cytotoxicity. All frontiers examining this approach in clinical practice deserve continued enthusiasm and cautious exploration while other factors are being fully understood and exploited.

Advances in rational combination chemotherapy.

Due to the high frequency of micro- or macrometastatic disease at the time of diagnosis of cancer, and to the increasing prevalence of cancer in this country, the use of chemotherapy to evoke cure or prolongation of survival has become critically important. In addition, the growth kinetics of large tumor burdens and the high probability of drug-resistant cells in a tumor mass at the time of diagnosis necessitate combinations of chemotherapeutic agents rather than single agents as the most effective mode of treatment. Since there are 40 to 50 active anticancer drugs now utilized, and since synergy between drug combinations is often dose and/or schedule dependent, the number of possible drug combinations and permutations is vast. Thus, screening for effective drug combinations requires a rational approach which will allow for accurate predictions of synergy. Most advances in this scientific approach have utilized biochemical modulation in conjunction with in vitro cytotoxicity assays, in particular, clonogenic assays. Such an approach has generated a number of drug combinations, such as sequential MTX-5FU, with widely applicable clinical efficacy. The continued use of biochemical modulation should rapidly generate new effective drug combinations which will, hopefully, allow us to cure even those cancers presently considered incurable.