Cobra (Naja Naja Atra) Membrane Toxin Isoforms: Structure and Function

Abstract

Two membrane toxins, termed MT-I and MT-II, were purified to HPLC homogeneity from the venom of Naja naja atra. The NH₂-terminal sequences of the two isoforms were determined. When compared with the known sequences of membrane toxins, we concluded they are CTX-I and CTX-III (from Naja naja atra), respectively. Membrane toxins are basic peptides typified by a chain of 60 amino acids long. Their pi is about 10 and Mr is 6,000-7,000. About half of the amino acids are hydrophobic.

There is lytic synergism between membrane toxins and phospholipase A₂. Membrane toxins, which are different from neurotoxins, are capable of depolarizing muscle cells. The toxins are able to kill cancer cells in vitro. Electrocardiograph of cat to which membrane toxin was applied shows magnificent changes. A positive correlation exists between hydrophobicities and activities of the toxins to inhibit protein kinase C (PKC) activity. All the effects are the result of action of the toxins on cell membranes. In addition, structure-activity relationships are investigated with the available comparative data for membrane toxins centering on LD₅₀, erythrocyte lysis, and muscle cell depolarization.     

Persistence and Decomposition of Hepatotoxic Microcystins Produced by Cyanobacteria in Natural Environment

Abstract

Microcystins, the cyclic heptapeptide toxins produced by cyanobacteria such as Microcystis, show tumor-promoting activity through inhibition of protein phosphatases 1 and 2A. They potentially threaten human health and are increasing the worldwide interest in the health risk asSoc. iated with cyanobacterial toxins. Microcystins are normally considered to be confined within cyanobacterial cells and to enter into the surrounding water after lysis and cell death under field conditions. Five pathways may be considered to contribute to natural routes of detoxification of the microcystins: (1) dilution, (2) adsorption, (3) thermal decomposition aided by temperature and pH, (4) photolysis and (5) biological degradation. In this review, we describe the persistence and decomposition of microcystins under the conditions mentioned above and discuss the fate of the toxins in the natural environment.     

Interplay Between CYP3A-Mediated Metabolism and Polarized Efflux of Terfenadine and Its Metabolites in Intestinal Epithelial Caco-2 (TC7) Cell Monolayers

Purpose. To further characterize cytochrome P450 (CYP) and P-glyco-protein (Pgp) expression in monolayers of the Caco-2 cell clone TC7, a cell culture model of the human intestinal epithelium. To study the interplay between CYP3A and Pgp as barriers to intestinal drug absorption in TC7 cells using terfenadine and its metabolites as substrates. Methods. mRNA expression of eight CYPs and Pgp was investigated in TC7 and parental Caco-2 (Caco-2p) cell monolayers using RT-PCR. The CYP3A kinetics was determined in microsomes from both cell lines. The transport, metabolism and efflux of terfenadine and its metabolites were investigated in TC7 monolayers. Results. Both TC7 and Caco-2p cells expressed mRNA for Pgp and several important CYPs. However, mRNA for CYP3A4 was detectable only from TC7 cells. The relative affinity of CYP3A for terfenadine metabolism in the two cell lines was comparable, but the maximum reaction rate in the TC7 cells was 8-fold higher. The rate of transport of terfenadine and its metabolites hydroxy-terfenadine (HO-T) and azacyclonol across TC7 monolayers was 7.1-, 3.5- and 2.1-fold higher, respectively, in the basolateral to apical direction than it was in the apical to basolateral (AP-BL) direction. Inhibition studies indicated that the efflux was mediated by Pgp. Ketoconazole increased the AP-BL transport terfenadine dramatically by inhibiting both terfenadine metabolism and Pgp efflux. Conclusions. Cell culture models such as TC7 provide qualitative information on drug interactions involving intestinal CYP3A and Pgp.     

Microbiota-derived uremic retention solutes: perpetrators of altered nonrenal drug clearance in kidney disease

Introduction: Scientific interest in the gut microbiota is increasing due to improved understanding of its implications in human health and disease. In patients with kidney disease, gut microbiota-derived uremic toxins directly contribute to altered nonrenal drug clearance. Microbial imbalances, known as dysbiosis, potentially increase formation of microbiota-derived toxins, and diminished renal clearance leads to toxin accumulation. High concentrations of microbiota-derived toxins such as indoxyl sulfate and p-cresol sulfate perpetrate interactions with drug metabolizing enzymes and transporters, which provides a mechanistic link between increases in drug-related adverse events and dysbiosis in kidney disease.

Areas covered: This review summarizes the effects of microbiota-derived uremic toxins on hepatic phase I and phase II drug metabolizing enzymes and drug transporters. Research articles that tested individual toxins were included. Therapeutic strategies to target microbial toxins are also discussed.

Expert commentary: Large interindividual variability in toxin concentrations may explain some differences in nonrenal clearance of medications. Advances in human microbiome research provide unique opportunities to systematically evaluate the impact of individual and combined microbial toxins on drug metabolism and transport, and to explore microbiota-derived uremic toxins as potential therapeutic targets.     

Antidiabetic effects of natural plant extracts via inhibition of carbohydrate hydrolysis enzymes with emphasis on pancreatic alpha amylase

Introduction: The increasing prevalence of type 2 diabetes mellitus and the negative clinical outcomes observed with the commercially available anti-diabetic drugs have led to the investigation of new therapeutic approaches focused on controlling postprandrial glucose levels. The use of carbohydrate digestive enzyme inhibitors from natural resources could be a possible strategy to block dietary carbohydrate absorption with less adverse effects than synthetic drugs.

Areas covered: This review covers the latest evidence regarding in vitro and in vivo studies in relation to pancreatic alpha-amylase inhibitors of plant origin, and presents bioactive compounds of phenolic nature that exhibit anti-amylase activity.

Expert opinion: Pancreatic alpha-amylase inhibitors from traditional plant extracts are a promising tool for diabetes treatment. Many studies have confirmed the alpha-amylase inhibitory activity of plants and their bioactive compounds in vitro, but few studies corroborate these findings in rodents and very few in humans. Thus, despite some encouraging results, more research is required for developing a valuable anti-diabetic therapy using pancreatic alpha-amylase inhibitors of plant origin.     

Targeting protein-bound uremic toxins in chronic kidney disease

Introduction: Protein-bound uremic toxins such as indoxyl sulfate cannot be removed efficiently by hemodialysis. These protein-bound uremic toxins have emerged as important risk factors for the progression of chronic kidney disease (CKD) as well as cardiovascular disease (CVD).

Areas covered: Indoxyl sulfate shows toxic effects on a variety of cells such as renal proximal tubular cells, glomerular mesangial cells, vascular smooth muscle cells, vascular endothelial cells, cardiomyocytes, cardiac fibroblasts, monocytes, osteoblasts and osteoclasts. This review overviews the cellular toxicity of indoxyl sulfate, its molecular mechanism and its role in the progression of CKD and CVD. Further, this review summarizes the clinical effects of AST-120 and the other strategies to reduce serum levels of indoxyl sulfate.

Expert opinion: Protein-bound uremic toxins such as indoxyl sulfate have emerged as target molecules for therapeutic intervention of not only CKD but also CVD. An oral sorbent AST-120 reduces serum level of indoxyl sulfate by adsorbing indole in the intestine. The modulation of intestinal bacteria by prebiotics/probiotics might be effective in reducing the production of indole in the intestine followed by reduced serum levels of indoxyl sulfate. An alternative approach might be antagonist which can counteract indoxyl sulfate-induced cellular effects and signaling pathways.     

Rattlesnake Neurotoxins: Biochemical and Biological Aspects

Abstract

A number of rattlesnake venoms contain potent neurotoxic protein complexes that have phospholipase A₂ activity. Data derived from studies of some of these neurotoxins indicate that neuromuscular transmission is blocked. The primary action appears to be at presynaptic sites, but at high doses interactions with cholinergic receptors reduce postsynaptic responses. The toxin complexes are mixtures of closely related isoforms, each composed of two distinct and separable subunits. The basic protein subunit is a phospholipase which is somewhat toxic whereas the acidic constituent is devoid of toxicity and lacks enzymatic activity. Even though the two subunits have quite different structures, they have considerable sequence similarity, suggesting a common ancestral origin. The acidic subunit enhances the lethal potency of the basic phospholipase component when the two are combined to generate a reconstituted toxin. Evidence suggests the acidic subunit reduces nonspecific binding of the basic phospholipase to membranes, thereby restricting binding of the neurotoxic component to specific sites on toxin sensitive membranes.

This class of toxins has not been used extensively to study subcellular membrane vesicles or cultured cells. Results from some of our studies with isolated rat brain synaptosomes demonstrated that Mojave toxin and the basic subunit isolated from Mojave toxin alter the uptake and release of neurotransmitters. Recent unpublished studies with cultured muscle cells showed marked effects on the fusion process in which primary myoblasts form myotubes. The toxin also reduces the formation of colonies from several clonal myoblast cell lines. The biochemical bases for these observations remain to be determined.     

In vitro effect of IL-2 in combination with pazopanib or sunitinib on lymphocytes function and apoptosis of RCC cells

Objective: Combination of immunotherapy with tyrosine kinase inhibitors (TKIs) has been used with some success for the treatment of metastatic renal cell carcinoma. Herein we evaluate the in vitro effect of high-dose interleukin-2 (HDIL-2) and pazopanib or sunitinib on the lymphocyte function and on induction of apoptosis in renal cell carcinoma (RCC) cell lines.

Methods: Peripheral blood mononuclear cells (PBMCs) isolated from healthy donors or RCC patients were treated with different HDIL-2/TKI combinations. Effects of different combinations on proliferation and cytotoxic activity of PBMCs were evaluated, in addition to their effect on apoptosis of three different RCC cell lines.

Results: While sunitinib did not inhibit the proliferation of various immune cells induced by HDIL-2, pazopanib appeared to inhibit the HDIL-2–induced proliferation of these cells. Interestingly, none of the HDIL-2/TKI combinations appeared to compromise the functional properties of these cells. Additionally, significant proportion of RCC cell lines treated with pazopanib alone underwent apoptosis, while the proportions of apoptotic cells post-HDIL-2 or sunitinib were not different from the background. Furthermore, the combination of HDIL-2/pazopanib did not inhibit the pazopanib-induced RCC apoptosis.

Conclusion: The combination of HDIL-2 with either pazopanib or sunitinib exerts different anticancer mechanisms that could enhance the treatment efficacy.     

Patent Evaluation: A New Approach to the Production of Human Monoclonal Antibodies

Summary

Novelty: A technique is described for the immortalization of human B-cells producing either IgG, IgM or IgA, thereby creating cell lines producing natural, human monoclonal antibodies. This technique may have major implications in the use of antibodies in human therapy where a lack of antigenicity is required. It will circumvent and simplify the current methods of humanizing mouse monoclonals.

Biology: Human blood is depleted of T-cells by rosetting and the resulting B-cell population of lymphocytes is transformed with Epstein Barr virus in conjunction with at least one of the cytokines, Interleukin-4 or Interleukin-6 plus 8-mercaptoguanosine. The cells are cloned out by limiting dilution in microliter trays and tested for antigen specific antibody production. Antibody production increases with time. IgG is produced in the largest quantities.     

Natural Protein Toxins Affecting Cutaneous Microvascular Permeability

Abstract

Natural toxins are found widespread from animal, plant and micro-organism sources. Presented here in review are recently discovered natural protein toxins that have in some way been shown to affect the permeability of the cutaneous micro-vasculature or skin capillaries.

Capillaries play a major role in the body by controlling the necessary normal balance of metabolites in the body's tissues and that of the blood. The trans-capillary exchanges of water and metabolites are regulated by the basal lamina, the internal activities of the endothelial cells and the driving forces on each side of the capillary wall. Edema, inflammation, urticaria, increased capillary permeability and cutaneous edema are conditions that are related. The main methods for detecting the increase in skin capillary permeability have been by using the rat paw edema assay, labelled albumin, or other detectable indicators.

Natural venoms and toxins sources causing edema include mammals, reptiles, amphibians, fishes, invertebrates, plants, and micro-organisms. Not all the substances causing increased capillary permeability are proteins such as certain alkaloids (Plants, fungi, fire ants and others) and normal endogenous substances e.g. histamine, serotonin, acetylcholine, (plants, snakes, and others) and are not considered in this review.

Recently, a large number of toxins (predominantly bacterial toxins) have been reported that produce increased cutaneous capillary permeability, some of which are known in some detail and selected toxins are discussed.

These studies have helped to understand the toxins, provided for more effective treatments, and helped to improve our knowledge of the capillaries and endothelial cells.     

Patent Evaluation: Antibody toxins for the treatment of bladder cancer

Summary

Novelty: Hybrid proteins comprising Pseudomonas Exotoxin-40 (PE₄₀) modified by removal of cysteine residues and linked to transforming growth factor α (TGF-α) are disclosed. The hybrids target bladder carcinoma cells through interaction of the TGF-α component and the upregulated epidermal growth factor receptor (EGF) borne on their surface. The hybrid exotoxin component then destroys the malignant cell.

Biology: Selected hybrids are assessed in an assay for cytotoxic activity against eight human bladder carcinoma cell lines and a variety of other carcinoma and blastoma cell lines. ED₅₀ values against the bladder lines range from 100–800 pM, with some lines affected only at very much higher concentrations. Cytotoxicity against a variety of lines is shown to be variable, with some non-bladder lines being affected at low doses.

Chemistry: Preparation of the hybrids is by conventional recombinant techniques comprising the construction of recombinant clones, modification of the clones and isolation of the fusion proteins. These stages are fully exemplified, with both nucleotide and amino acid sequences being provided.     

Oxysterol receptors and their therapeutic applications in cancer conditions

Introduction: Oxysterols are implicated in various cellular processes. Among their target proteins, liver X receptors (LXRs) α and β modulate the cell cycle in a large range of cancer cell lines. Besides their role as cholesterol sensors, LXRs are also involved in the proliferation/apoptosis balance regulation in various types of cancers.

Areas covered: This review covers oxysterols and derivatives of cholesterol as well as synthetic or natural ligands (agonist/antagonist) of LXRs. Most tumor cell lines are sensitive to LXR activation. Indeed various cancers are concerned such as prostate, breast, glioblastoma, colorectal, and ovary tumors, and leukemia.

Expert opinion: Developing the use of LXR ligands in human health, especially in the field of cancer, represents a novel and promising strategy. Despite a wide spectrum of applications, numerous adverse effects of LXR activation need to be solved before genuine clinical trials in humans. Future directions will be based on the engineering of selective LXRs modulators (SLiMs) as already done for nuclear steroid receptors.     

Applications of stable V79-derived cell lines expressing rat cytochromes P4501A1, 1A2, and 2B1

1. Chinese hamster V79-derived cell lines, stably expressing cytochromes P4501A1, 1A2, and 2B1 activities, were constructed by genetic engineering in continuation of our work to establish a battery of V79 derived cell lines designed to study the metabolism of xenobiotics.

2. Cell lines XEM1 and XEM2, expressing cytochrome P4501A1, were capable of the O-dealkylation of 7-ethoxycoumarin and the hydroxylation of benzo[a]pyrene.

3. Cell lines XEMd.MZ and XEMd.NH, expressing P4501A2, were shown to hydroxylate 17β-estradiol and 2-aminofluorene.

4. Cell line SD1, expressing cytochrome P4502B1, was able to hydroxylate testosterone stereo- and regio-specifically at the 16α and 16β positions.

5. Cell lines were validated in mutagenicity, cytotoxicity, and metabolism studies employing benzo[a]pyrene, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene, cyclophos-phamide, ifosfamide, and picene.

6. Construction of metabolically-competent V79-derived cell lines be recombinant DNA technology will be a fundamental improvement for the evaluation of the cytotoxic, genotoxic and pharmacological properties of a chemical.     

Antiproliferative effect of alkaloids via cell cycle arrest from Pseuduvaria rugosa

Context: Pseuduvaria rugosa (Blume) Merr. (Annonacaea) grows widely in the south and southeast regions of Thailand. Preliminary screening for biological activities revealed that crude hexane, ethyl acetate, and acetone extracts from mixtures of leaves and twigs of P. rugosa showed cytotoxicity.

Objective: Chemical constituents and their antiproliferative activity in K562, U937, and HL-60 human leukemic cell lines from P. rugosa were performed for the first time.

Materials and methods: The isolated compounds were obtained from chromatographic separation. The structures were established by spectroscopic techniques including IR, UV, NMR together with 2D NMR (HMBC, COSY, and NOE) and MS. The K562, U937, and HL-60 cell lines were treated with isolated aporphine alkaloids (0–100 µg/mL) and cell viability was measured with the MTT assay. Cell cycle analysis was performed using propidium iodide (PI) based staining methods.

Results: Two known aporphine alkaloids, 1,2,3-trimethoxy-5-oxonoraporphine (1) and ouregidione (2) were isolated. Treatment of the cells with compounds 1 and 2 at a concentration of 100 µg/mL for 72?h reduced the viability of K562, U937, and HL-60 cell lines to 63 and 64, 38 and 66, and 49 and 64%, respectively. In addition, compounds 1 and 2, at a concentration of 100 µg/mL, exposed to U937 and HL-60 cell lines showed cell cycle arrest. The U937 cell line treated with compounds 1 and 2 increased significantly the proportion of the cell in S phase, whereas the HL-60 cell line-induced G2/M and G1 phase, respectively.

Discussion and conclusion: The results showed that 1,2,3-trimethoxy-5-oxonoraporphine and ouregidione-induced cytotoxicity with HL-60, U937, and K562 cells where 1,2,3-trimethoxy-5-oxonoraporphine was more active than ouregidione.     

Applications of CRISPR genome editing technology in drug target identification and validation

Introduction: The analysis of pharmaceutical industry data indicates that the major reason for drug candidates failing in late stage clinical development is lack of efficacy, with a high proportion of these due to erroneous hypotheses about target to disease linkage. More than ever, there is a requirement to better understand potential new drug targets and their role in disease biology in order to reduce attrition in drug development. Genome editing technology enables precise modification of individual protein coding genes, as well as noncoding regulatory sequences, enabling the elucidation of functional effects in human disease relevant cellular systems.

Areas covered: This article outlines applications of CRISPR genome editing technology in target identification and target validation studies.

Expert opinion: Applications of CRISPR technology in target validation studies are in evidence and gaining momentum. Whilst technical challenges remain, we are on the cusp of CRISPR being applied in complex cell systems such as iPS derived differentiated cells and stem cell derived organoids. In the meantime, our experience to date suggests that precise genome editing of putative targets in primary cell systems is possible, offering more human disease relevant systems than conventional cell lines.     

Patent Evaluation : WO9310130-: Istituto Nazionale per la Ricerca sul Cancro: Triamino platinum complexes and their potential as anticancer agents

Novelty: Triamino platinum complexes are claimed. They are stated to have in vivo antitumour activity without renal toxicity. They may be used to treat cancer.

Biology: Compounds had significant cytotoxicity in vitro against P388 murine leukaemic cells, K562 human erythroleukaemic cells, Jurkat human cells and cisplatin-resistant tumour cells. The preferred compound (cis-DPR) was evaluated in vitro on cisplatin-resistant L1210 murine leukaemic cell lines (24 hr thymidine-uptake method). IC₅₀ values were about 10 times superior to cisplatin. BDF1 mice infected with P388 leukaemic cells showed a significant increase in lifespan compared with cisplatin.

Chemistry: An example is provided for the preparation of cis-diamino-chloro-4-[diethylammoniumethoxycarbonylphenyl]amino-platinum (II) bis-chloride monohydrate (cis-DPR). This is the preferred compound used in the tests. Characterization is by mp, ir, uv and elemental analysis.     

Evaluation of the cytotoxic potential of a new pentacyclic triterpene from Rhododendron arboreum stem bark

Context: Traditionally, Rhododendron arboreum Sm. (Ericaceae) is a very important medicinal plant having oxytocic, estrogenic, anti-inflammatory, analgesic and hepatoprotective activities; it also inhibits the prostaglandin synthetase.

Objectives: This study determines the cytotoxic potential of 15-oxoursolic acid isolated from R. arboreum against selected human cancer cell lines.

Materials and methods: Extraction from stem bark (5?kg) of R. arboreum was performed with methanol, which was successively partitioned into hexane, dichloromethane and ethyl acetate fractions, respectively. The new antitumor agent [15-oxoursolic acid (1)] was isolated from ethyl acetate fraction through column chromatography. Structure elucidation of new compound was performed through extensive spectroscopy i.e., IR, MS and 1D and 2D NMR. Cytotoxicity of isolated compound was determined at doses 5–100?μM for a period of 72?h on specified human cancer cell lines [renal cell carcinoma (A498), non-small cell lung (NCI-H226), squamous cell carcinoma (H157) and human ovarian carcinoma (MDR-2780AD)].

Results: Structure of isolated compound was characterized as 15-oxoursolic acid on the basis of various extensive spectroscopic techniques. 15-Oxoursolic acid revealed considerable anticancer activity with IC₅₀ values of 2.3?±?0.1?μM, 4.9?±?0.2?μM, 9.2?±?0.2?μM and 10.3?±?0.1?μM against MDR 2780AD, Hep G2, H157 and NCI-H226, respectively, while in the case of A498, the activity was good (IC₅₀ 32.8?±?1.2?μM).

Conclusions: This study highlighted the potential of 15-oxoursolic acid to be further explored as a new lead compound for cancer chemotherapy.     

Effect of endoplasmic reticulum stress preconditioning on cytotoxicity of clinically relevant nephrotoxins in renal cell lines.

The cytoprotection of LLC-PK1 cells afforded by endoplasmic reticulum (ER) stress preconditioning suggests that the ER plays an important role during drug-induced renal toxicity. However, in vitro studies have been largely limited to LLC-PK1 cells and model toxins. Therefore, we tested the hypothesis that cytoprotection following ER stress preconditioning is a common property of renal cell lines (LLC-PK1 (pig), NRK-52E (rat), HEK293 (human), MDCK (dog)) and extends to clinically relevant nephrotoxins. ER stress inducers (tunicamycin, thapsigargin and oxidized dithiothreitol (DTTox)) resulted in a dose-dependent increase in GRP78 and GRP94 stress protein expression, but the magnitude of induction was cell line- and inducer-dependent. Toxicity of the model toxins iodoacetamide and tert-butylhydroperoxide was modified by preconditioning. DTTox was effective in decreasing the toxicity in all cell lines, but protection was variable with tunicamycin and thapsigargin. Toxicity of clinically relevant drugs (cisplatin, gentamicin, glyoxylate, cyclosporine A, p-aminophenol) was significantly decreased in cells preconditioned by tunicamycin or DTTox. These results demonstrate that ER stress preconditioning offers cytoprotection against clinically relevant nephrotoxins in renal cell lines from multiple species, although there were qualitative and quantitative differences between the cell lines. These results support the hypothesis that ER is involved in drug-induced renal toxicity.     

Novel dietary lipid-based self-nanoemulsifying drug delivery systems of paclitaxel with p-gp inhibitor: implications on cytotoxicity and biopharmaceutical performance

Objectives: This work describes the development and characterization of novel self-nanoemulsifying drug delivery systems (SNEDDS) employing polyunsaturated fatty acids for enhancing the oral bioavailability and anticancer activity of paclitaxel (PTX) by coadministration with curcumin (Cu).

Methods: Preformulation studies endorsed sesame oil, labrasol, and sodium deoxycholate as lipid surfactants and cosurfactants based on their solubility for the drugs and spontaneity of emulsification to produce nanoemulsions. Further, phase titration studies were performed to identify a suitable nanoemulsion region for preparing the SNEDDS formulation.

Results: The prepared formulations were characterized through in vitro, in situ, and in vivo studies to evaluate the biopharmaceutical performance. In vitro drug release studies showed 2.8- to 3.4-fold enhancement in the dissolution rate of both drugs from SNEDDS as compared with the pure drug suspension. Cell line studies revealed 1.5- to 2.7-fold reduction in the cytotoxicity on MCF-7 cells by plain PTX-SNEDDS and PTX-Cu-SNEDDS vis-à-vis the PTX-suspension. In situ intestinal perfusion studies revealed significant augmentation in permeability and absorption parameters of drug from PTX-Cu-SNEDDS over the plain PTX-SNEDDS and PTX-suspension (p < 0.001). In vivo pharmacokinetic studies also showed a remarkable improvement (i.e., 5.8- to 6.3-fold) in the oral bioavailability (C_max and AUC) of the drug from PTX-SNEDDS and PTX-Cu-SNEDDS vis-à-vis the PTX-suspension.

Conclusions: Overall, the studies corroborated superior biopharmaceutical performance of PTX-Cu-SNEDDS.     

Enhancing the efficiency of bortezomib conjugated to pegylated gold nanoparticles: an in vitro study on human pancreatic cancer cells and adenocarcinoma human lung alveolar basal epithelial cells

ABSTRACT

Objectives: Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells.

Methods: Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines.

Results: We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h’ incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC₅₀ value of free BTZ is respectively 1.5 and 4.3 times higher than the IC₅₀ value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC₅₀ value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs.

Conclusions: Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).