Selenium nanoparticles as a carrier of 5-fluorouracil to achieve anticancer synergism

Topical Delivery of 5-Fluorouracil from Pheroid™ Formulations and the In Vitro Efficacy Against Human Melanoma

Drug delivery vehicles can influence the topical delivery and the efficacy of an active pharmaceutical ingredient (API). In this study, the influence of Pheroid™ technology, which is a unique colloidal drug delivery system, on the skin permeation and antimelanoma efficacy of 5-fluorouracil were investigated. Lotions containing Pheroid™ with different concentrations of 5-fluorouracil were formulated then used in Franz cell skin diffusion studies and tape stripping. The in vitro efficacy of 5-fluorouracil against human melanoma cells (A375) was investigated using a flow cytometric apoptosis assay. Statistically significant concentrations of 5-fluorouracil diffused into and through the skin with Pheroid™ formulations resulting in an enhanced in vitro skin permeation from the 4.0% 5-fluorouracil lotion (p < 0.05). The stratum corneum-epidermis and epidermis-dermis retained 5-fluorouracil concentrations of 2.31 and 6.69 μg/ml, respectively, after a diffusion study with the 4.0% Pheroid™ lotion. Subsequent to the apoptosis assay, significant differences were observed between the effect of 13.33 μg/ml 5-fluorouracil in Pheroid™ lotion and the effects of the controls. The results obtained suggest that the Pheroid™ drug delivery system possibly enhances the flux and delivery of 5-fluorouracil into the skin. Therefore, using Pheroid™ could possibly be advantageous with respect to topical delivery of 5-fluorouracil.

The rational design of NAMI-A-loaded mesoporous silica nanoparticles as antiangiogenic nanosystems

Angiogenesis is essential for tumorous progression and metastasis. The RGD (Arg-Gly-Asp acid) peptide has been demonstrated to be a remarkable targeting reagent and can be distinguished by the integrin receptor overexpressed in various human tumor cells. Mesoporous silica nanoparticles (MSNs) are one of the most promising carriers applied for delivery of drugs or genes. It is well known that NAMI-A is an excellent drug for antimigration of tumor cells. Targeting the tumor vasculature with RGD-modified nanomaterials is expected to be a promising strategy for cancer therapy. Herein we have investigated the antiangiogenic activity of NAMI-A-loaded and RGD peptide surface decorated mesoporous silica nanoparticles in vitro and in vivo. The results revealed that NAMI-A@MSN-RGD remarkably enhanced the cellular uptake and antiangiogenic efficacy in contrast to bare NAMI-A in vitro. The nanosystem of NAMI-A@MSN-RGD also exhibited inspiring antiangiogenic action in vivo. Furthermore, the RGD-functionalized nanodrug inhibited angiogenesis by means of apoptosis by triggering ROS-mediated DNA damage in human umbilical vein endothelial cells (HUVECs). Our results suggested that the use of RGD-peptide modified MSNs as a vehicle of anticancer drugs is an efficient way to construct cancer-targeted nanosystems with antiangiogenic activity.

Synthesis and antioxidant properties of chitosan and carboxymethyl chitosan-stabilized selenium nanoparticles

Monodispersible selenium nanoparticles (SeNPs) were synthesized by using chitosan (CS) and carboxymethyl chitosan (CCS) as the stabilizer and capping agent using a facile synthetic approach. The structure, size, morphology and antioxidant activity of the nanocomposites were characterized by transmission electron microscopy (TEM), Ultraviolet-visible spectroscopy (UV-vis), Dynamic Light Scattering (DLS), Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA). The results revealed that the monodispersible SeNPs (mean particle size of about 50 nm) were ligated with CS and CCS to form nanocomposites in aqueous solution for at least 30 days, and for 120 days the nanoparticles increased to 180 nm or so in size. The DPPH scavenging ability of CS-SeNPs was higher than that of CCS-SeNPs, and could reach 93.5% at a concentration of 0.6 mmol/L. Moreover, SeNPs, CS-SeNPs and CCS-SeNPs exhibited a higher ABTS scavenging ability in comparison to Na2SeO3.

Hsa-miR-132 inhibits proliferation of hepatic carcinoma cells by targeting YAP

MicroRNAs and Yes-associated protein (YAP) play an important role in the occurrence and development of hepatic carcinomas. However, the interaction between microRNAs and YAP was seldom elucidated. In this study, we showed that miR-132 could target YAP gene by using dual-luciferase reporter system. Further quantitative polymerase chain reaction analysis and western blotting showed that miR-132 could significantly reduce the expression of YAP at mRNA and protein levels. Results of annexin V-fluorescein isothiocyanate, 5-ethynyl-2'-deoxyuridine staining and transwell assays showed that miR-132 significantly promoted the cell apoptosis and effectively inhibited the proliferation and invasion of hepatoma cells. These results indicated that miR-132 could inhibit the growth of hepatoma cells by targeting YAP gene and reducing its expression level. Taken together, results from this study would help us to understand the mechanisms for occurrence and development of hepatic carcinoma and provide new targets for diagnosis and treatment of liver cancer.

The inhibitory effect of selenium nanoparticles on protein glycation in vitro

Selenium nanoparticles (Se NPs) possess well-known excellent biological activities and low toxicity, and have been employed for numerous applications except as inhibitors to protein glycation. Herein, the present study is carried out to investigate the inhibitory effect of Se NPs on protein glycation in a bovine serum albumin (BSA)/glucose system. By measuring the amount of glucose covalently bound onto BSA, the formation of fructosamine and fluorescent products, it is found that Se NPs can hinder the development of protein glycation in a dose-dependent but time-independent manner under the selected reaction conditions (55 °C, 40 h). And after comparing the increase of inhibitory rate in different stages, it is observed that Se NPs show the greatest inhibitory effect in the early stage, then in the advanced stage, but no effect in the intermediate stage. Fourier transform infrared spectroscopy characterization of Se NPs collected after glycation and determination of ·OH influence and glyoxal formation show that the mechanism for the inhibitory efficacy of Se NPs is related to their strong competitive activity against available amino groups in proteins, their great scavenging activity on reactive oxygen species and their inhibitory effect on α-dicarbonyl compounds' formation. In addition, it is proved that Se NPs protect proteins from structural modifications in the system and they do not exhibit significant cytotoxicity towards BV-2 and BRL-3A cells at low concentrations (10 and 50 μg mL(-1)). Consequently, Se NPs may be suitable for further in vivo studies as novel anti-glycation agents.

Synthesis of selenazolopyridine derivatives with capability to induce apoptosis in human breast carcinoma MCF-7 cells through scavenge of intracellular ROS

A series of selenazolopyridine derivatives have been synthesized and characterized by X-ray diffraction, high resolution NMR and Mass spectrum. The in vitro anticancer activities of the synthetic compounds were screened against a panel of human cancer cell lines, human breast carcinoma MCF-7 cells, human liver carcinoma HepG2 cells and L02 normal cell line by MTT assay. By analyzing the structure-activity relationship among the synthetic compounds, it was found that 2-(phenylamino) selenazolo [5,4-b] pyridine, (PSeD, 7) had higher growth inhibitory effect on MCF-7 cells. The intracellular mechanism of cell death was evaluated by flow cytometric analysis and ROS assay, which revealed that PSeD could induce MCF-7 cells apoptosis by scavenging intracellular ROS. Taken together, we regard PSeD as an antioxidant which could inhibit cancer cell growth through induction of apoptosis.

Rational design of cancer-targeted selenium nanoparticles to antagonize multidrug resistance in cancer cells

Multidrug resistance is one of the greatest challenges in cancer therapy. Herein we described the synthesis of folate (FA)-conjugated selenium nanoparticles (SeNPs) as cancer-targeted nano-drug delivery system for ruthenium polypyridyl (RuPOP) exhibits strong fluorescence, which allows the direct imaging of the cellular trafficking of the nanosystem. This nanosystem could effectively antagonize against multidrug resistance in liver cancer. FA surface conjugation significantly enhanced the cellular uptake of SeNPs by FA receptor-mediated endocytosis through nystain-dependent lipid raft-mediated and clathrin-mediated pathways. The nanomaterials overcame the multidrug resistance in R-HepG2 cells through inhibition of ABC family proteins expression. Internalized nanoparticles triggered ROS overproduction and induced apoptosis by activating p53 and MAPKs pathways. Moreover, FA-SeNPs exhibited low in vivo acute toxicity, which verified the safety and application potential of FA-SeNPs as nanodrugs. This study provides an effective strategy for the design of cancer-targeted nanodrugs against multidrug resistant cancers.

FROM THE CLINICAL EDITOR

In the combat against hepatocellular carcinoma, multidrug resistance remains one of the obstacles to be overcome. The authors designed and synthesized folate (FA)-conjugated selenium nanoparticles (SeNPs) with enhanced cancer-targeting capability. This system carried ruthenium polypyridyl (RuPOP), an efficient metal-based anti-cancer drug with strong fluorescence. It was shown that this combination was effective in antagonizing against multidrug resistance in vitro.

Carboxylic group-induced synthesis and characterization of selenium nanoparticles and its anti-tumor potential on Dalton's lymphoma cells

Carboxylic group-induced synthesis of selenium nanoparticles (SeNPs) was achieved using sodium selenosulphate as a precursor. The particles were stabilized and capped with 0.01% polyvinyl alcohol under ambient conditions. This is a simple and easy method of producing SeNPs in a size range from 35 to 105 nm. The synthesized SeNPs were purified by centrifugation at 11,500 × g for 20 min and characterized by UV-visible spectroscopy, FTIR spectroscopy, XRD, DSC and TEM. It was observed that the synthesized SeNPs showed differences in their absorption spectra, phase composition and crystal structure, thermodynamic behaviour, size and shape. Further, to confirm anti-tumour potential of the synthesized SeNPs induced by the carboxylic group of acetic acid, pyruvic acid and benzoic acid, cell viability assay, nuclear morphology testing and DNA fragmentation assay were carried out using Dalton's lymphoma (DL) cells. DL cells treated with the SeNPs showed reduced cell viability, altered nuclear morphology, typical apoptotic DNA ladder and apoptosis. Therefore, these SeNPs may have therapeutic relevance to treat this type of cancer.

Multicomponent 5-fluorouracil loaded PAMAM stabilized-silver nanocomposites synergistically induce apoptosis in human cancer cells

Herein, we report the development of a poly(amidoamine) (PAMAM) dendrimer based multicomponent therapeutic agent forin vitrocancer therapy applications.

Ruthenium complexes as inhibitors of human islet amyloid polypeptide aggregation, an effect that prevents beta cell apoptosis

Herein we show that ruthenium complexes could inhibit fibrosis of hIAPP and protect the hIAPP-induced cell damage by suppressing ROS generation, indicating the application potential of the complexes in treatment of T2DM by targeting hIAPP.

Selenadiazole derivatives as theranostic agents for simultaneous cancer chemo-/radiotherapy by targeting thioredoxin reductase

Herein we have identified selenadiazole derivatives as effective and safe theranostic agents for simultaneous cancer chemo-/radiotherapy.

Localized drug delivery of selenium (Se) using nanoporous anodic aluminium oxide for bone implants

Release behavior and cancer toxicity of different forms of Se loaded into nanoporous AAO were studied.

Construction of a cancer-targeted nanosystem as a payload of iron complexes to reverse cancer multidrug resistance

This study demonstrates the construction of a cancer-targeted nanosystem as payload of iron complexes to reverse cancer multidrug resistance.

Dual-functional carbon dots–silver@zinc oxide nanocomposite: in vitro evaluation of cellular uptake and induction of apoptosis

We report here the devleopment of novel CDs decorated on a silver–zinc oxide (CD–Ag@ZnO) nanocomposite (NC) consisting of highly fluorescent CDs and Ag@ZnO.

Rational design and fabrication of a cancer-targeted chitosan nanocarrier to enhance selective cellular uptake and anticancer efficacy of selenocystine

A cancer-targeted chitosan nanocarrier has been rationally designed to enhance the selective cellular uptake and anticancer efficacy of selenocystine.

Nanovesicular carrier-based formulation for skin cancer targeting: evaluation of cytotoxicity, intracellular uptake, and preclinical anticancer activity

CONTEXT

Skin cancer has turned into global epidemic leading to higher incidences among cancer stricken population.

OBJECTIVE

The aim of the present investigation is to evaluate the anticancer potential and intracellular uptake of a novel nanovesicular formulation of 5-FU.

MATERIALS AND METHODS

Detailed intracellular uptake study in conjunction with estimation of intracellular reactive oxygen species was done using skin melanoma cell lines (A375) along with cytotoxicity studies. To further obtain the mechanistic insights into inhibition of tumor cell proliferation, cell-cycle arrest studies were conducted. The preclinical anticancer activity was carried out employing in vivo DMBA-croton oil-induced skin cancer model in mice.

RESULTS AND DISCUSSION

Significant reduction in the number of papillomas was observed in skin cancer-bearing mice on treatment with nanovesicular formulation (51.4 ± 3.2%) in comparison with marketed formulation (21.3 ± 2.1%) of 5-FU. Tumor volume was found to be reduced to 46.3 ± 3.5% with prepared formulation, whereas the marketed formulation-treated group showed the reduction of 18.6 ± 1.8% in comparison with the control (untreated) group.

CONCLUSION

The results of present study demonstrated that nanovesicular formulation of 5-FU possessed the enhanced anticancer activity which could be attributed to better intracellular uptake, cellular retention, and sustained release of drug.

Chitosan-decorated selenium nanoparticles as protein carriers to improve the in vivo half-life of the peptide therapeutic BAY 55-9837 for type 2 diabetes mellitus

PURPOSE

As a potential protein therapeutic for type 2 diabetes mellitus (T2DM), BAY 55-9837 is limited by poor stability and a very short half-life in vivo. The purpose of this study was to construct a novel nanostructured biomaterial by conjugating BAY 55-9837 to chitosan-decorated selenium nanoparticles (CS-SeNPs) to prolong the in vivo half-life of BAY 55-9837 by reducing its renal clearance rate.

MATERIALS AND METHODS

BAY 55-9837-loaded CS-SeNPs (BAY-CS-SeNPs) were prepared, and their surface morphology, particle size, zeta potential, and structure were characterized. The stability, protein-loading rate, and in vitro release of BAY 55-9837 from CS-SeNPs were also quantified. Additionally, a sensitive high-performance liquid chromatography (HPLC) assay was developed for the quantification of BAY 55-9837 in mouse plasma. Thereafter, mice were injected via the tail vein with either BAY 55-9837 or BAY-CS-SeNPs, and the plasma concentration of BAY 55-9837 was determined via our validated HPLC method at different time intervals postinjection. Relevant in vivo pharmacokinetic parameters (half-life, area under the curve from time 0 to last sampling point, observed clearance) were then calculated and analyzed.

RESULTS

BAY-CS-SeNPs were successfully synthesized, with diameters of approximately 200 nm. BAY-CS-SeNPs displayed good stability with a high protein-loading rate, and the release process of BAY 55-9837 from the CS-SeNPs lasted for over 70 hours, with the cumulative release reaching 78.9%. Moreover, the conjugation of CS-SeNPs to BAY 55-9837 significantly reduced its renal clearance to a rate of 1.56 mL/h and extended its half-life to 20.81 hours.

CONCLUSION

In summary, our work provides a simple method for reducing the renal clearance rate and extending the half-life of BAY 55-9837 in vivo by utilizing CS-SeNPs as nanocarriers.

Cyclic peptide-selenium nanoparticles as drug transporters

A cyclic peptide composed of five tryptophan, four arginine, and one cysteine [W5R4C] was synthesized. The peptide was evaluated for generating cyclic peptide-capped selenium nanoparticles (CP-SeNPs) in situ. A physical mixing of the cyclic peptide with SeO3(-2) solution in water generated [W5R4C]-SeNPs via the combination of reducing and capping properties of amino acids in the peptide structure. Transmission electron microscopy (TEM) images showed that [W5R4C]-SeNPs were in the size range of 110-150 nm. Flow cytometry data revealed that a fluorescence-labeled phosphopeptide (F'-PEpYLGLD, where F' = fluorescein) and an anticancer drug (F'-dasatinib) exhibited approximately 25- and 9-times higher cellular uptake in the presence of [W5R4C]-SeNPs than those of F'-PEpYLGLD and dasatinib alone in human leukemia (CCRF-CEM) cells after 2 h of incubation, respectively. Confocal microscopy also exhibited higher cellular delivery of F'-PEpYLGLD and F'-dasatinib in the presence of [W5R4C]-SeNPs compared to the parent fluorescence-labeled drug alone in human ovarian adenocarcinoma (SK-OV-3) cells after 2 h of incubation at 37 °C. The antiproliferative activities of several anticancer drugs doxorubicin, gemcitabine, clofarabine, etoposide, camptothecin, irinotecan, epirubicin, fludarabine, dasatinib, and paclitaxel were improved in the presence of [W5R4C]-SeNPs (50 μM) by 38%, 49%, 36%, 36%, 31%, 30%, 30%, 28%, 24%, and 17%, respectively, after 48 h incubation in SK-OV-3 cells. The results indicate that CP-SeNPs can be potentially used as nanosized delivery tools for negatively charged biomolecules and anticancer drugs.

Gracilaria lemaneiformis polysaccharide as integrin-targeting surface decorator of selenium nanoparticles to achieve enhanced anticancer efficacy

The poor permeability of glioma parenchyma represents a major limit for antiglioblastoma drug delivery. Gracilaria lemaneiformis polysaccharide (GLP), which has a high binding affinity to αvβ3 integrin overexpressed in glioma cells, was employed in the present study to functionalize selenium nanoparticles (SeNPs) to achieve antiglioblastoma efficacy. GLP-SeNPs showed satisfactory size distribution, high stability, and selectivity between cancer and normal cells. In U87 glioma cell membrane, which has a high integrin expression level, GLP-SeNPs exhibited significantly higher cellular uptake than unmodified SeNPs. As expected, U87 cells exhibited a greater uptake of GLP-SeNPs than C6 cells with low integrin expression level. Furthermore, the internalization of GLP-SeNPs was inhibited by cyclo-(Arg-Gly-Asp-Phe-Lys) peptides, suggesting that cellular uptake into U87 cells and C6 cells occurred via αvβ3 integrin-mediated endocytosis. For U87 cells, the cytotoxicity of SeNPs decorated by GLP was enhanced significantly because of the induction of various apoptosis signaling pathways. Internalized GLP-SeNPs triggered intracellular reactive oxygen species downregulation. Therefore, p53, MAPKs, and AKT pathways were activated to advance cell apoptosis. These findings suggest that surface decoration of nanomaterials with GLP could be an efficient strategy for design and preparation of glioblastoma targeting nanodrugs.

Effective inhibition of colon cancer cell growth with MgAl-layered double hydroxide (LDH) loaded 5-FU and PI3K/mTOR dual inhibitor BEZ-235 through apoptotic pathways

Colon cancer is the third most common cancer and the third largest cause of cancer-related death. Fluorouracil (5-FU) is the front-line chemotherapeutic agent for colon cancer. However, its response rate is less than 60%, even in combination with other chemotherapeutic agents. The side effects of 5-FU also limit its application. Nanoparticles have been used to deliver 5-FU, to increase its effectiveness and reduce side effects. Another common approach for colon cancer treatment is targeted therapy against the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. A recently-invented inhibitor of this pathway, BEZ-235, has been tested in several clinical trials and has shown effectiveness and low side effects. Thus, it is a very promising drug for colon cancer treatment. The combination of these two drugs, especially nanoparticle-packed 5-FU and BEZ-235, has not been studied. In the present study, we demonstrated that nanoparticles of layered double hydroxide (LDH) loaded with 5-FU were more effective than a free drug at inhibiting colon cancer cell growth, and that a combination treatment with BEZ-235 further increased the sensitivity of colon cancer cells to the treatment of LDH-packed 5-FU (LDH-5-FU). BEZ-235 alone can decrease colon cancer HCT-116 cell viability to 46% of the control, and the addition of LDH-5-FU produced a greater effect, reducing cell survival to 8% of the control. Our data indicate that the combination therapy of nanodelivered 5-FU with a PI3K/Akt inhibitor, BEZ-235, may promise a more effective approach for colon cancer treatment.

Inhibition of islet amyloid polypeptide fibril formation by selenium-containing phycocyanin and prevention of beta cell apoptosis

Human islet amyloid polypeptide (hIAPP) fibril is the major constituent of amyloid deposits in pancreatic islets of type 2 diabetes. Misfolding and hIAPP fibril formation are thought to be important in the pathogenesis of diabetes. Studies have showed that selenium-containing phycocyanin (Se-PC) inhibited the fibrillation of hIAPP to form nanoscale particles, which is mainly by interfering with the combination between hIAPP. Small nanoscale oligomers tended to grow into larger nanoparticles and the size of nanoparticles increased with the incubation time. By interfering with the fibrillation of hIAPP and altering the structure, Se-PC alleviated hIAPP-induced cell apoptosis. Meantime, generation of ROS produced during the fibrillation process was inhibited, which was proposed to be the main factor for the hIAPP-cytotoxicity in beta cells. Taken together, Se-PC inhibited hIAPP fibrillation, thus suppressed the formation of ROS to show protective effect on hIAPP mediated cell apoptosis. Our studies provide useful information for our understanding of the interaction mechanisms of Se-PC on hIAPP structure and protective mechanisms on hIAPP cytotoxicity, presenting useful candidate for anti-diabetes drug development.

Enhancement of auranofin-induced lung cancer cell apoptosis by selenocystine, a natural inhibitor of TrxR1 in vitro and in vivo

Thioredoxin reductase (TrxR) is overpressed in many human tumors and has a key role in regulating intracellular redox balance. Recently, thioredoxin system has emerged as a valuable target for anticancer drug development. Herein we demonstrate that selenocystine (SeC) could enhance auranofin (AF)-induced A549 human lung adenocarcinoma cell apoptosis in vitro and in vivo through synergetic inhibition of TrxR1. SeC pretreatment significantly enhanced AF-induced loss of mitochondrial membrane potential (Δψ_m) by regulating Bcl-2 family proteins. The combined treatment with SeC and AF also resulted in enhanced intracellular reactive oxygen species (ROS) accumulation, DNA damage, and inactivation of ERK and AKT. Inhibitors of ERK and AKT effectively enhanced combined treatment-induced apoptotic cell death. However, inhibition of ROS reversed the apoptosis induced by SeC and AF, and recovered the inactivation of ERK and AKT, which revealed the importance of ROS in cell apoptosis and regulation of ERK and AKT pathways. Moreover, xenograft lung tumor growth in nude mice was more effectively inhibited by combined treatment with SeC and AF by induction of apoptosis through targeting TrxR1 in vivo. Taken together, our results suggest the strategy to use SeC and AF in combination could be a highly efficient way to achieve anticancer synergism by targeting TrxR1.

The effect of microneedles on the skin permeability and antitumor activity of topical 5-fluorouracil

Topical 5-fluorouracil (5-FU) is approved for the treatment of superficial basal cell carcinoma and actinic keratosis. However, 5-FU suffers from poor skin permeation. Microneedles have been successfully applied to improve the skin permeability of small and large molecules, and even nanoparticles, by creating micron-sized pores in the stratum corneum layer of the skin. In this report, the feasibility of using microneedles to increase the skin permeability of 5-FU was tested. Using full thickness mouse skin mounted on Franz diffusion apparatus, it was shown that the flux of 5-FU through the skin was increased by up to 4.5-fold when the skin was pretreated with microneedles (500 μm in length, 50 μm in base diameter). In a mouse model with B16-F10 mouse melanoma cells implanted in the subcutaneous space, the antitumor activity of a commercially available 5-FU topical cream (5%) was significantly enhanced when the cream was applied on a skin area that was pretreated with microneedles, as compared to when the cream was simply applied on a skin area, underneath which the tumor cells were implanted, and without pretreatment of the skin with microneedles. Fluorouracil is not approved for melanoma therapy, but the clinical efficacy of topical 5-FU against tumors such as basal cell carcinoma may be improved by integrating microneedle technology into the therapy.

Selenium substitution endows cystine with radiosensitization activity against cervical cancer cells

Selenium substitution could endow cystine the radiosensitization activity against cervical cancer HeLa cells through overproduction of ROS and activation of downstream signaling, which suggests this could be a novel strategy for design of cancer radiosensitizers.

pH-responsive cancer-targeted selenium nanoparticles: a transformable drug carrier with enhanced theranostic effects

A cancer-targeted and structure-transformable drug delivery system has been constructed, which displays enhanced anticancer efficacy and exhibits the characteristics of shape transformation and pH-controlled drug release under acidifying cell organelles.

Undecylprodigiosin conjugated monodisperse gold nanoparticles efficiently cause apoptosis in colon cancer cells in vitro

Bacterial pigment undecylprodigiosin was conjugated to monodisperse gold nanoparticles, resulting in improved stability and cytotoxicity against colon cancer cells.

Aptamer-functionalized graphene oxide for highly efficient loading and cancer cell-specific delivery of antitumor drug

A novel anticancer drug loading and cell-specific delivery system based on cell-type-specific aptamer-functionalized graphene oxide is reported.

Combination of fenretinide and selenite inhibits proliferation and induces apoptosis in ovarian cancer cells

The combination of fenretinide and selenite on ovarian cancer cells was investigated to assess its effects on proliferation and ability to induce apoptosis. Our results showed that fenretinide and selenite in combination significantly suppress the proliferation of ovarian cancer cells and induced apoptosis (including reactive oxygen species generation, and the loss of mitochondrial membrane potential) compared with either drug used alone. The caspase3/9-dependent pathway was triggered significantly in combination treatment, and moreover, the AMPK pathway also mediated the apoptosis induction in fenretinide and selenite combination. Fenretinide and selenite combination treatment was demonstrated to suppress tumor growth in vivo, this drug combination has been thus found to have an enhanced anti-tumor effect on ovarian cancers cells.

Potent anticancer activity of cystine-based dipeptides and their interaction with serum albumins

BACKGROUND

Cancer is a severe threat to the human society. In the scientific community worldwide cancer remains a big challenge as there are no remedies as of now. Cancer is quite complicated as it involves multiple signalling pathways and it may be caused by genetic disorders. Various natural products and synthetic molecules have been designed to prevent cell proliferation. Peptide-based anticancer drugs, however, are not explored properly. Though peptides have their inherent proteolytic instability, they could act as anticancer agents.

RESULTS

In this present communication a suitably protected cystine based dipeptide and its deprotected form have been synthesized. Potent anticancer activities were confirmed by MTT assay (a laboratory test and a standard colorimetric assay, which measures changes in colour, for measuring cellular proliferation and phase contrast images. The IC50 value, a measure of the effectiveness of a compound in inhibiting biological or biochemical function, of these compounds ranges in the sub-micromolar level. The binding interactions with serum albumins (HSA and BSA) were performed with all these molecules and all of them show very strong binding at sub-micromolar concentration.

CONCLUSIONS

This study suggested that the cystine-based dipeptides were potential anticancer agents. These peptides also showed very good binding with major carrier proteins of blood, the serum albumins. We are currently working on determining the detailed mechanism of anticancer activity of these molecules.