Multidrug Resistance In Cancer Cells Research Articles

Biosynthesis of silver nanoparticles (Ag-NPs) using Senna alexandrina grown in Saudi Arabia and their bioactivity against multidrug-resistant pathogens and cancer cells

There is no doubt that the risk of drug-resistant pathogens and cancer diseases is on the rise. So, the goal of this study was to find out how effective silver nanoparticles (Ag-NPs) made by Senna alexandrina are at fighting these threats.In this work, S. alexandrina collected from Medina, Saudi Arabia was used and the biosynthesis method was applied to produce the Ag-NPs. The characterization of Ag-NPs was done using different analytical techniques, including UV spectroscopy, FT-IR, TEM, and XRD analysis. The MIC, MBC, and MTT protocols were applied to confirm the bioactivity of the Ag-NPs as antibacterial and anticancer bioagents. The findings reported indicating that the aqueous extract of S. alexandrina leaves, grown naturally in Saudi Arabia, is ideal for the production of bioactive Ag-NPs. The hydroxyl, aliphatic, alkene, N–H bend of primary amines, C–H bonds, and C-O bonds of alcohol were detected in this product. The small, sphere-shaped particles (4–7 nm) were the most prevalent among the bioactive Ag-NPs produced in this work. These nanoparticles inhibited some important multidrug-resistant pathogens (MDRPs) (Escherichia coli, Acinetobacter baumanii/haemolyticus, Staphylococcus epidermidis, and Methicillin-resistant Staphylococcus aureus (MRSA)), as well as their ability to inhibit breast cancer cells (MCF-7 cells). The MIC of Ag-NPs ranged from 0.03 to 0.6 mg/mL, while their MBC ranged from 0.06 to 2.5 mg/mL.Anticancer activity test showed that IC50 of the Ag-NPs against tested breast cancer cells was 61.9 ± 3.8 µg/mL. According to the current results, biosynthesis using S. alexandrina leaves grown naturally in Saudi Arabia was an ideal technique for producing bioactive Ag-NPs that could be used to combat a variety of MDRPs and cancer diseases.

Cymbopogon citratus and Citral Overcome Doxorubicin Resistance in Cancer Cells via Modulating the Drug's Metabolism, Toxicity, and Multidrug Transporters.

Multidrug resistance (MDR) is the major complex mechanism that causes the failure of chemotherapy, especially with drugs of natural origin such as doxorubicin (DOX). Intracellular drug accumulation and detoxification are also involved in cancer resistance by reducing the susceptibility of cancer cells to death. This research aims to identify the volatile composition of Cymbopogon citratus (lemon grass; LG) essential oil and compare the ability of LG and its major compound, citral, to modulate MDR in resistant cell lines. The composition of LG essential oil was identified using gas chromatography mass spectrometry (GC-MS). In addition, a comparison of the modulatory effects of LG and citral, performed on breast (MCF-7/ADR), hepatic (HepG-2/ADR), and ovarian (SKOV-3/ADR) MDR cell lines, were compared to their parent sensitive cells using the MTT assay, ABC transporter function assays, and RT-PCR. Oxygenated monoterpenes (53.69%), sesquiterpene hydrocarbons (19.19%), and oxygenated sesquiterpenes (13.79%) made up the yield of LG essential oil. α-citral (18.50%), β-citral (10.15%), geranyl acetate (9.65%), ylangene (5.70), δ-elemene (5.38%), and eugenol (4.77) represent the major constituents of LG oil. LG and citral (20 μg/mL) synergistically increased DOX cytotoxicity and lowered DOX dosage by >3-fold and >1.5-fold, respectively. These combinations showed synergism in the isobologram and CI < 1. DOX accumulation or reversal experiment confirmed that LG and citral modulated the efflux pump function. Both substances significantly increased DOX accumulation in resistant cells compared to untreated cells and verapamil (the positive control). RT-PCR confirmed that LG and citral targeted metabolic molecules in resistant cells and significantly downregulated PXR, CYP3A4, GST, MDR1, MRP1, and PCRP genes. Our results suggest a novel dietary and therapeutic strategy combining LG and citral with DOX to overcome multidrug resistance in cancer cells. However, these results should be confirmed by additional animal experiments before being used in human clinical trials.

Chitosan loaded plant essential oils efficiently eradicate the multi-drug resistant bacterial infection and lung cancer cells

In present research, of chitosan loaded plant essential oils (CsEOs) were performed against Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E.coli), K. pneumoniae and Staphylococci aureus (S. aureus), also the anti-cancer properties were evaluated against A549 lung cancer cells. Consequently, the CsEOs against P. aeruginosa, E.coli, K. pneumoniae and Staphylococci aureus were shown 24 mm, 22 mm, and 26 mm and 22 mm zones of inhibition respectively. In addition, 500 µg/mL of CsEOs exhibited 92, 89, 88 and 94% of inhibition against P. aeruginosa, E.coli, K. pneumoniae and S. aureus were observed respectively using micro broth dilution broth experiment. Further, cytotoxicity ability of CsEOs against A549 human lung cancer cells were monitored by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, and result of 500 µg/mL concentration was exhibited 58% inhibition against A549 lung cancer cells. Furthermore, the microscopic evidence of 500 µg/mL concentrations of CsEOs treated A549 lung cancer cells was showed irregular morphology in phase contrast microscope. Altogether, both the invitro and morphological experiments of anti-bacterial and anti-cancer study results were conveyed that the CsEOs have excellent anti-bacterial and anti-cancer properties. Finally, the entire study was proposed, the chosen CsEOs was excellent bionanomaterial used to deliver the drugs and bioactive compounds in target sites for inhibit the infectious pathogens and cancer cells.

Abstract 4947: Exploration of Annamycin Organotropism to Target Primary and Metastatic Liver Cancers

Abstract Background. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is responsible for more than 12,000 deaths per year in the US. In addition to primary tumors, the liver is a common site for metastases of many types of cancer, including colorectal, and pancreatic cancer. The life expectancy and outlook for people with liver metastases are typically poor.Annamycin (ANN) is a novel anthracycline of our design that is clinically evaluated as a liposome formulated drug product, L-ANN. ANN and L-ANN display unique organotropism that differs from doxorubicin (DOX). In addition, ANN was shown to have increased potency against multidrug resistant cancer cell lines, and, importantly, L-ANN appeared to be non-cardiotoxic. Objective. The objective of this study was to analyze the pharmacokinetics of two formulations of ANN in the liver in comparison with DOX and to determine its tumoricidal potential in an HCC model in situ and in an experimental model of liver metastasis. Methods. The pharmacokinetics and tissue-organ distribution studies of L-ANN, free ANN, or DOX were performed in mice and rats. The levels of ANN and DOX in plasma and tissue homogenates were assessed using LC/MS. The antitumor efficacy of L-ANN was studied using HEPA 1-6 hepatocellular carcinoma models (subcutaneous, orthotopic, and experimental liver metastatic models) and compared with CT26 colon cancer liver metastasis experiments.Results. ANN exhibited dramatically higher accumulation in the liver parenchyma when compared to DOX (6-fold higher AUC values). We found that the increased liver uptake of the drug had a direct effect on activity of the drug in vivo. First, we observed clear, dose-dependent inhibition of the subcutaneous tumor growth after systemic (IV) administration of L-ANN. Next, remarkable activity of L-ANN was observed in orthotopic models. For instance, significant inhibition of the tumor growth and extension of the survival of L-ANN treated mice vs. vehicle-receiving animals was observed in HEPA 1-6 models (median survival 29.5 vs 50 days (p&amp;lt;0.0001) and 28 vs 59 days (p&amp;lt;0.0001), respectively). The significant delay in tumor progression was similar to that recorded in the CT26 experimental metastatic models, and L-ANN treatment strongly correlated with survival in this model as well (median survival 32 vs 53 days in L-ANN and vehicle groups, respectively, p&amp;lt;0.0001).Conclusions. Annamycin is a potent, non-cardiotoxic anthracycline with proven in vivo activity against different types of tumors. It showed increased penetration and accumulation in the liver, which correlated with high antitumor activity in HEPA 1-6 hepatocellular carcinoma and CT26 colon cancer liver metastasis models. Expanded studies to assess L-ANN activity in different tumor liver metastasis models as well as HCC models are being planned. It should be noted that L-ANN is currently undergoing clinical trials in patients with pulmonary metastasis soft tissue sarcoma and acute myeloid leukemia. Citation Format: Rafal J. Zielinski, Krzysztof Grela, Shaohua Peng, Edd Felix, Roberto Cardenas-Zuniga, Damian Grybowski, Stanislaw Skora, Izabela Fokt, Waldemar Priebe. Exploration of Annamycin Organotropism to Target Primary and Metastatic Liver Cancers. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4947.

ABCB1 and ABCG2 Overexpression Mediates Resistance to the Phosphatidylinositol 3-Kinase Inhibitor HS-173 in Cancer Cell Lines.

Constitutive activation of the phosphoinositide-3-kinase (PI3K)/Akt signaling pathway is crucial for tumor growth and progression. As such, this pathway has been an enticing target for drug discovery. Although HS-173 is a potent PI3K inhibitor that halts cancer cell proliferation via G2/M cell cycle arrest, the resistance mechanisms to HS-173 have not been investigated. In this study, we investigated the susceptibility of HS-173 to efflux mediated by the multidrug efflux transporters ABCB1 and ABCG2, which are two of the most well-known ATP-binding cassette (ABC) transporters associated with the development of cancer multidrug resistance (MDR). We found that the overexpression of ABCB1 or ABCG2 significantly reduced the efficacy of HS-173 in human cancer cells. Our data show that the intracellular accumulation of HS-173 was substantially reduced by ABCB1 and ABCG2, affecting G2/M arrest and apoptosis induced by HS-173. More importantly, the efficacy of HS-173 in multidrug-resistant cancer cells could be recovered by inhibiting the drug-efflux function of ABCB1 and ABCG2. Taken together, our study has demonstrated that HS-173 is a substrate for both ABCB1 and ABCG2, resulting in decreased intracellular concentration of this drug, which may have implications for its clinical use.

Enhanced therapeutic efficacy of doxorubicin against multidrug-resistant breast cancer with reduced cardiotoxicity

Doxorubicin (DOX), a commonly used anti-cancer drug, is limited by its cardiotoxicity and multidrug resistance (MDR) of tumor cells. Epigallocatechin gallate (EGCG), a natural antioxidant component, can effectively reduce the cardiotoxicity of DOX. Meanwhile, EGCG can inhibit the expression of P-glycoprotein (P-gp) and reverse the MDR of tumor cells. In this study, DOX is connected with low molecular weight polyethyleneimine (PEI) via hydrazone bond to get the pH-sensitive PEI-DOX, which is then combined with EGCG to prevent the cardiotoxicity of DOX and reverse the MDR of cancer cells. In addition, folic acid (FA) modified polyethylene glycol (PEG) (PEG-FA) is added to get the targeted system PEI-DOX/EGCG/FA. The MDR reversal and targeting ability of PEI-DOX/EGCG/FA is performed by cytotoxicity and in vivo anti-tumor activity on multidrug resistant MCF-7 cells (MCF-7/ADR). Additionally, we investigate the anti-drug resistant mechanism by Western Blot. The ability of EGCG to reduce DOX cardiotoxicity is confirmed by cardiotoxicity assay. In conclusion, PEI-DOX/EGCG/FA can inhibit the expression of P-gp and reverse the MDR in tumor cells. It also shows the ability of remove oxygen free radicals effectively to prevent the cardiotoxicity of DOX.

In Silico Exploration of Microtubule Agent Griseofulvin and Its Derivatives Interactions with Different Human β-Tubulin Isotypes

Tubulin isotypes are known to regulate microtubule stability and dynamics, as well as to play a role in the development of resistance to microtubule-targeted cancer drugs. Griseofulvin is known to disrupt cell microtubule dynamics and cause cell death in cancer cells through binding to tubulin protein at the taxol site. However, the detailed binding mode involved molecular interactions, and binding affinities with different human β-tubulin isotypes are not well understood. Here, the binding affinities of human β-tubulin isotypes with griseofulvin and its derivatives were investigated using molecular docking, molecular dynamics simulation, and binding energy calculations. Multiple sequence analysis shows that the amino acid sequences are different in the griseofulvin binding pocket of βI isotypes. However, no differences were observed at the griseofulvin binding pocket of other β-tubulin isotypes. Our molecular docking results show the favorable interaction and significant affinity of griseofulvin and its derivatives toward human β-tubulin isotypes. Further, molecular dynamics simulation results show the structural stability of most β-tubulin isotypes upon binding to the G1 derivative. Taxol is an effective drug in breast cancer, but resistance to it is known. Modern anticancer treatments use a combination of multiple drugs to alleviate the problem of cancer cells resistance to chemotherapy. Our study provides a significant understanding of the involved molecular interactions of griseofulvin and its derivatives with β-tubulin isotypes, which may help to design potent griseofulvin analogues for specific tubulin isotypes in multidrug-resistance cancer cells in future.

Nano-carrier Polyamidoamine Dendrimer G4 Induces Mitochondrialdependent Apoptosis in Human Multidrug-resistant Breast Cancer Cells through G0/G1 Phase Arrest.

Multidrug-resistant tumor cells have special drug detoxification/inactivation mechanisms. The terminal amino groups of the polyamidoamine (PAMAM-NH2), which is cytotoxic to tumor sensitive cells, may have no cytotoxicity in tumor resistant cells with a mechanism different from tumor sensitive cells. This study aimed to investigate the cytotoxic effects of PAMAM-G4-NH2 on human multidrug- resistant breast cancer cells (MCF-7/ADR cells) and identify the possible molecular mechanisms. The cytotoxicity of PAMAM-G4-NH2 (10-1000 μg/mL) against MCF-7 and MCF-7/ADR cells was detected. Then, MCF-7 and MCF-7/ADR cells were treated with PAMAM-G4-NH2 (10, 100 and 1000 μg/mL), and apoptosis, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), activities of caspase-3, -8 and -9 and cell cycle distribution were determined. Within 48 h, the cell viabilities in MCF-7/ADR cells after treatment with PAMAM-G4-NH2 were significantly higher than that in MCF-7 cells in the concentration range of 200-500 μg/mL (P < 0.05). Viabilities of MCF-7/ADR cells treated with PAMAM-G4-OH and PAMAM-G4-COOH for 48 and 72 h were much higher than that of MCF-7/ADR cells treated with PAMAM-G4-NH2. Treated with high concentration (1000 μg/mL) of PAMAM-G4-NH2 for 24 h, the apoptosis ratio, ROS levels, as well as caspase-3 and -9 activities in MCF-7 and MCF-7/ADR cells increased, while MMP decreased, and the cells were arrested in the G0/G1 phase. PAMAM-G4-NH2 induced concentration-dependent cytotoxicity in MCF-7/ADR cells via G0/G1 arrest, and acted through h the mitochondria-dependent apoptotic pathway, which was similar to those in tumor sensitive cell, MCF-7 cells. The results suggest that PAMAM-G4-NH2, instead of PAMAM-G4-OH and PAMAM-G4-COOH, can be used as a carrier for drug delivery, concomitantly, it can also induce apoptosis in multidrug-resistant cancer cells in combination with the loaded drug through multiple apoptotic pathways.

Recent advances in the strategic incorporation of fluorine into new-generation taxoid anticancer agents

This account describes our recent progress on the strategic incorporation of fluorine and organofluorine moieties into new-generation taxoid anticancer agents for medicinal chemistry and chemical biology studies.In the case study 1, novel 3rd-generation fluorotaxoids bearing 3-OCF3 or 3-OCF2H group in the C2-benzoate moiety were designed, synthesized and examined for their anticancer activities. The potency of novel taxoids against drug-resistant cancer cell lines was 2–3 orders of magnitude higher than that of paclitaxel (PTX). Molecular modeling analysis indicated the favorable van der Waals interactions of OCF3 and OCHF2 groups in the binding site. Overall, taxoids bearing a OCHF2 group at the C2 benzoate position exhibited the highest potencies against multidrug-resistant (MDR) cancer cell lines and cancer stem cell (CSC)-enriched cell lines, indicating that the new 3rd-generation fluorotaxoids are promising candidates as chemotherapeutic agents.In the case study 2, novel 3rd-generation 3′-difluorovinyl (DFV)-taxoids, bearing 3-CF3O or 3-CHF2O group in the C2-benzoyl moiety, were designed, synthesized, and evaluated for their potencies and pharmacological properties. These new DFV-taxoids exhibited remarkable cytotoxicity against extremely drug-resistant cancer cell lines with subnanomolar IC50 values, indicating that these new DFV-taxoids can overcome MDR caused by the overexpression of Pgp and other ABC cassette transporters. The molecular docking analysis of new DFV-taxoids revealed that the 3′-DFV moiety and the 3-CF3O/3-CHF2O group of the C2-benzoate moiety are nicely accommodated to the deep hydrophobic pocket of the PTX/taxoid binding site in the β-tubulin, enabling an enhanced binding through unique attractive interactions between F/OCF3/OCHF2 and the protein. This enhancement in binding is reflected in the remarkable high potency of new 3rd-generation DFV-taxoids.In the case study 3.1, the therapeutic potential of new 3rd-generation DFV-taxoids in anaplastic thyroid cancer (ATC) cells was evaluated in vitro and in vivo. This study demonstrated that these new DFV-taxoids were more efficacious than PTX against ATC cell lines and tumor xenografts, as demonstrated by the efficient inhibition of cell proliferation and colony formation, induction of apoptosis via the mitotic arrest at the G2/M phase, as well as the suppression of tumorigenic potential in nude mice. Furthermore, tubulin polymerization assay and molecular docking analysis confirmed that these new DFV-taxoids promoted far more rapid polymerization of β-tubulin than PTX through stronger binding to tubulin/microtubules. Taken together, this study has indicated a promising therapeutic potential of these new DFV-taxoids against ATC.In the case study 3.2, DFV-OTX displayed potent cytotoxicity and effective induction of β-tubulin polymerization, as well as the G2/M phase arrest, leading to apoptosis in PTX-sensitive and PTX-resistant breast cancer cells. Furthermore, DFV-OTX clearly exhibited efficacy against MCF-7R and MDA-MB-231R tumor xenografts in mouse models. Thus, DFV-OTX effectively overcame PTX-resistance in MDA-MB-231R cells and tumor xenografts, wherein the drug resistance was attributed to ABCB1/ABCG2 upregulation. DFV-OTX was also effective against MCF-7R cells and tumor xenografts, which are PTX-resistant due to different MOA. Accordingly, DFV-OTX is a promising chemotherapeutic agent for the treatment of PTX-resistant cancers.Overall, these next-generation fluorotaxoids are promising candidates for highly potent chemotherapeutic agents, as well as payloads for tumor-targeting drug conjugates such as antibody-drug conjugates (ADCs).

Nanoparticle drug delivery systems for synergistic delivery of tumor therapy.

Nanoparticle drug delivery systems have proved anti-tumor effects; however, they are not widely used in tumor therapy due to insufficient ability to target specific sites, multidrug resistance to anti-tumor drugs, and the high toxicity of the drugs. With the development of RNAi technology, nucleic acids have been delivered to target sites to replace or correct defective genes or knock down specific genes. Also, synergistic therapeutic effects can be achieved for combined drug delivery, which is more effective for overcoming multidrug resistance of cancer cells. These combination therapies achieve better therapeutic effects than delivering nucleic acids or chemotherapeutic drugs alone, so the scope of combined drug delivery has also been expanded to three aspects: drug-drug, drug-gene, and gene-gene. This review summarizes the recent advances of nanocarriers to co-delivery agents, including i) the characterization and preparation of nanocarriers, such as lipid-based nanocarriers, polymer nanocarriers, and inorganic delivery carriers; ii) the advantages and disadvantages of synergistic delivery approaches; iii) the effectual delivery cases that are applied in the synergistic delivery systems; and iv) future perspectives in the design of nanoparticle drug delivery systems to co-deliver therapeutic agents.

Designing of new tetrahydro-β-carboline-based ABCG2 inhibitors using 3D-QSAR, molecular docking, and DFT tools

Human ATP-binding cassette superfamily G member 2 (ABCG2) protein is a member of the ABC transporter family, which is responsible for multidrug resistance (MDR) in cancerous cells. MDR reduces the effectiveness of chemotherapy in breast cancer, which is one of the leading causes of death in women globally. MDR in cancer cells is one of the immediate signs of progression of resistance; thus, various anticancer drugs can be designed. To reduce MDR, we utilized the tetrahydro-β-carboline (THβC) compound library. We accomplished a three-dimensional quantitative structure-activity relationship (3D-QSAR), scaffold hopping to design a new library of compounds of THβC, and further molecular docking, induced-fit docking (IFD), molecular mechanics energies combined with generalized born and surface area continuum solvation (MM-GBSA), drug-like features, ADMET properties, and density functional theory (DFT) studies were performed. From these studies, the best 3D-QSAR model (r2 = 0.99, q2 = 0.92) was found, and the necessity of electrostatic, steric, and hydrophobic field effects were determined that could modulate bioactivity. Moreover, based on electrostatic, steric, and hydrophobic field notations, new THβC derivatives (3409) were designed. These findings might provide new insight for researchers to perform in vitro and in vivo studies for better antagonists against MDR in treating breast cancer.Communicated by Ramaswamy H. Sarma

Effect of Cellular and Microenvironmental Multidrug Resistance on Tumor-Targeted Drug Delivery in Triple-Negative Breast cancer.

Multidrug resistance (MDR) reduces the efficacy of chemotherapy. Besides inducing the expression of drug efflux pumps, chemotherapy treatment alters the composition of the tumor microenvironment (TME), thereby potentially limiting tumor-directed drug delivery. To study the impact of MDR signaling in cancer cells on TME remodeling and nanomedicine delivery, we generated multidrug-resistant 4T1 triple-negative breast cancer (TNBC) cells by exposing sensitive 4T1 cells to gradually increasing doxorubicin concentrations. In 2D and 3D cell cultures, resistant 4T1 cells are presented with a more mesenchymal phenotype and produced increased amounts of collagen. While sensitive and resistant 4T1 cells showed similar tumor growth kinetics in vivo, the TME of resistant tumors was enriched in collagen and fibronectin. Vascular perfusion was also significantly increased. Fluorophore-labeled polymeric (∼10nm) and liposomal (∼100nm) drug carriers were administered to mice with resistant and sensitive tumors. Their tumor accumulation and penetration were studied using multimodal and multiscale optical imaging. At the whole tumor level, polymers accumulate more efficiently in resistant than in sensitive tumors. For liposomes, the trend was similar, but the differences in tumor accumulation were insignificant. At the individual blood vessel level, both polymers and liposomes were less able to extravasate out of the vasculature and penetrate the interstitium in resistant tumors. In a final in vivo efficacy study, we observed a stronger inhibitory effect of cellular and microenvironmental MDR on liposomal doxorubicin performance than free doxorubicin. These results exemplify that besides classical cellular MDR, microenvironmental drug resistance features should be considered when aiming to target and treat multidrug-resistant tumors more efficiently.

Nanocracker capable of simultaneously reversing both P-glycoprotein and tumor microenvironment.

Here, we describe a multidrug-resistant nanocracker (MDRC) that can treat multi-drug resistant (MDR) cancer by recognizing the acidic microenvironment and inhibiting two mechanisms of MDR such as P-glycoprotein (P-gp) and vacuolar-type ATPase (V-ATPase). MDRC is a liposome formulation co-loading pantoprazole (PZ) and paclitaxel (PTX). PZ acts as a chemosensitizer that enhances the MDR cancer treatment effect of PTX by disrupting the pH gradient and inhibiting P-gp. MDRC-encapsulated PZ and PTX have different release rates, with PZ released within 12h and PTX sustained release for 48h in the plasma. MDRC could increase cell uptake by inhibiting the P-gp overexpressed MCF-7/mdr cells and UV-2237M cells, which are human breast MDR cancer cells and murine fibrosarcoma cells, respectively. MDRC can also increase the cytotoxic efficacy of PTX by increasing intracellular pH. MDRC has a 10.5-fold reduced IC50 value in the P-gp overexpressed human breast adenocarcinoma and a 6.3- to 9.5-fold reduced IC50 value in the P-gp non-expressed human breast adenocarcinoma compared to the mixture of PZ and PTX, respectively. Intravenous injection of MDRC did not cause weight loss, liver dysfunction, or major organ toxicity. MDRC exhibited 80% complete remission of murine fibrosarcoma. The excellent therapeutic effect of MDRC on MDR tumors was accompanied by an increase in dendritic cell maturation and cytotoxic T cells. In other words, MDRC has the potential to terminate MDR therapy through the complete remission of MDR tumors.

Pinostrobin and Tectochrysin Conquer Multidrug-Resistant Cancer Cells via Inhibiting P-Glycoprotein ATPase.

Enhanced drug efflux through ATP-binding cassette transporters, particularly P-glycoprotein (P-gp), is a key mechanism underlying multidrug resistance (MDR). In the present study, we investigated the inhibitory effects of pinostrobin and tectochrysin on P-gp in MDR cancer cells and the underlying mechanisms. Fluorescence substrate efflux assays, multidrug resistance 1 (MDR1) shift assays, P-gp ATPase activity assays, Western blotting, and docking simulation were performed. The potential of the test compounds for MDR reversal and the associated molecular mechanisms were investigated through cell viability assay, cell cycle analysis, apoptosis assay, and further determining the combination index. Results demonstrated that pinostrobin and tectochrysin were not the substrates of P-gp, nor did they affect the expression of this transporter. Both compounds noncompetitively inhibited the efflux of rhodamine 123 and doxorubicin through P-gp. Furthermore, they resensitized MDR cancer cells to chemotherapeutic drugs, such as vincristine, paclitaxel, and docetaxel; thus, they exhibited strong MDR reversal effects. Our findings indicate that pinostrobin and tectochrysin are effective P-gp inhibitors and promising candidates for resensitizing MDR cancer cells.

Combination Chemotherapy of Multidrug-resistant Early-stage Colon Cancer: Determining Optimal Dose Schedules by High-performance Computer Simulation.

The goal of this project was to utilize mechanistic simulation to demonstrate a methodology that could determine drug combination dose schedules and dose intensities that would be most effective in eliminating multidrug resistant cancer cells in early-stage colon cancer. An agent-based model of cell dynamics in human colon crypts was calibrated using measurements of human biopsy specimens. Mutant cancer cells were simulated as cells that were resistant to each of two drugs when the drugs were used separately. The drugs, 5-flurouracil and sulindac, have different mechanisms of action. An artificial neural network was used to generate nearly two hundred thousand two-drug dose schedules. A high-performance computer simulated each dose schedule as a in silico clinical trial and evaluated each dose schedule for its efficiency to cure (eliminate) multidrug resistant cancer cells and its toxicity to the host, as indicated by continued crypt function. Among the dose schedules that were generated, 2430 dose schedules were found to cure all multidrug resistant mutants in each of the 50 simulated trials and retained colon crypt function. One dose schedule was optimal; it eliminated multidrug resistant cancer cells with the minimum toxicity and had a time schedule that would be practical for implementation in the clinic. These results demonstrate a procedure to identify which combination drug dose schedules could be most effective in eliminating drug resistant cancer cells. This was accomplished using a calibrated agent-based model of a human tissue, and a high-performance computer simulation of clinical trials.

Feature-Based Molecular Networking for the Exploration of the Metabolome Diversity of Common Egyptian Centaurea Species in Relation to Their Cytotoxic Activity

Centaurea is a genus compromising over 250 herbaceous flowering species and is used traditionally to treat several ailments. Among the Egyptian Centaurea species, C. lipii was reported to be cytotoxic against multidrug-resistant cancer cells. In this context, we aimed to explore the metabolome of C. lipii and compare it to other members of the genus in pursuance of identifying its bioactive principles. An LC-MS/MS analysis approach synchronized with feature-based molecular networks was adopted to offer a holistic overview of the metabolome diversity of the Egyptian Centaurea species. The studied plants included C. alexandrina, C. calcitrapa, C. eryngioides, C. glomerata, C. lipii, C. pallescens, C. pumilio, and C. scoparia. Their constitutive metabolome showed diverse chemical classes such as cinnamic acids, sesquiterpene lactones, flavonoids, and lignans. Linking the recorded metabolome to the previously reported cytotoxicity identified sesquiterpene lactones as the major contributors to this activity. To confirm our findings, bioassay-guided fractionation of C. lipii was adopted and led to the isolation of the sesquiterpene lactone cynaropicrin with an IC50 of 1.817 µM against the CCRF-CEM leukemia cell line. The adopted methodology highlighted the uniqueness of the constitutive metabolome of C. lipii and determined the sesquiterpene lactones to be the responsible cytotoxic metabolites.

Cancer-cell-membrane-camouflaged supramolecular self-assembly of antisense oligonucleotide and chemodrug for targeted combination therapy.

The anti-apoptotic B-cell lymphoma-2 (Bcl-2) family of proteins are critical regulators of cell death that are overexpressed in many cancer cells, especially in multi-drug resistant cancer cells. Combinatorial gene- and chemotherapies using antisense oligonucleotides (ASOs) to suppress the expression of Bcl-2-family mRNA and restore the sensitivity of the cell to chemodrugs provide a promising pathway for anticancer treatment. However, intrinsic differences between macromolecular ASOs and small molecular chemodrugs make their co-delivery challenging. Moreover, extraneous carriers may induce immunogenicity and inflammation problems. Herein, we develop a targeted nanodrug delivery system using the cationic amphiphilic chemodrug mitoxantrone (Mito), which interacts with Bcl-2 ASO through electrostatic interaction and self-assembles into nanoparticles (NP[Bcl-2/Mito]), whose size can be controlled by regulating the ratio of ASO and Mito. NP[Bcl-2/Mito] can protect the ASO from degradation during delivery and combine gene- and chemotherapies to improve the anticancer effect. Furthermore, cancer cell membranes (CCMs) derived from homologous tumors were used to camouflage NP[Bcl-2/Mito] (NP[Bcl-2/Mito]@CCM) to achieve immune escape and tumor targeting. Both in vitro and in vivo assessments demonstrate the excellent performance of NP[Bcl-2/Mito]@CCM for drug-resistant breast tumor therapy. This CCM-camouflaged ASO/chemodrug nanoplatform provides a promising pathway for the targeted delivery of ASOs and chemodrugs for tumor combination therapy.

CCT251545 enhances drug delivery and potentiates chemotherapy in multidrug-resistant cancers by Rac1-mediated macropinocytosis.

It was well known that P-glycoprotein (P-gp/ABCB1) is a master regulator of multidrug resistance (MDR) in cancers. However, the clinical benefit from blocking this pathway remains inconclusive, which motivates a paradigm shift towards alternative strategies for enhancing drug influx. Using a patient-derived organoid (PDO)-based drug screening platform, we report that the combined use of chemotherapy and CCT251545 (CCT) displays robust synergistic effect against PDOs and reduces proliferation of MDR cancer cells in vitro, and results in regression of xenograft tumors, reductions in metastatic dissemination and recurrence rate in vivo. The synergistic activity mediated by CCT can be mainly attributed to the intense uptake of chemotherapeutic agents into the cells, accompanied by alterations in cell phenotypes defined as a mesenchymal epithelial transformation (MET). Mechanistically, analysis of the transcriptome coupled with validation in cellular and animal models demonstrate that the chemosensitizing effect of CCT is profoundly affected by Rac1-dependent macropinocytosis. Furthermore, CCT binds to NAMPT directly, resulting in elevated NAD levels within MDR cancer cells. This effect promotes the assembly of adherents junction (AJ) components with cytoskeleton, which is required for continuous induction of macropinocytosis and consequent drug internalization. Overall, our results illustrate the potential use of CCT as a combination partner for the commonly used chemotherapeutic drugs in the management of MDR cancers.

ABC transporters affects tumor immune microenvironment to regulate cancer immunotherapy and multidrug resistance.

Multidrug resistance (MDR) is the phenomenon in which cancer cells simultaneously develop resistance to a broad spectrum of structurally and mechanistically unrelated drugs. MDR severely hinders the effective treatment of cancer and is the major cause of chemotherapy failure. ATP-binding cassette (ABC) transporters are extensively expressed in various body tissues, and actively transport endogenous and exogenous substrates through biological membranes. Overexpression of ABC transporters is frequently observed in MDR cancer cells, which promotes efflux of chemotherapeutic drugs and reduces their intracellular accumulation. Increasing evidence suggests that ABC transporters regulate tumor immune microenvironment (TIME) by transporting various cytokines, thus controlling anti-tumor immunity and sensitivity to anticancer drugs. On the other hand, the expression of various ABC transporters is regulated by cytokines and other immune signaling molecules. Targeted inhibition of ABC transporter expression or function can enhance the efficacy of immune checkpoint inhibitors by promoting anticancer immune microenvironment. This review provides an update on the recent research progress in this field.

Novel artesunate–pyrimidine-based hybrids with anticancer potential against multidrug-resistant cancer cells

Approach based on hybrid compounds of artesunate and pyrimidine provided novel and promising anticancer agents.