Reversal Of Multiple Drug Resistance Research Articles

Artesunate-loaded solid lipid nanoparticles resist esophageal squamous cell carcinoma by inducing Ferroptosis through inhibiting the AKT/mTOR signaling

Esophageal squamous cell carcinoma (ESCC) is a severe malignancy with high incidence and mortality rate in China, while the application of standard chemotherapeutic drugs for ESCC meets the barriers of high toxicity and multiple drug resistance (MDR). In recent years, the anticancer effects of artesunate (ART), a Chinese medicine monomer have gained extensive attentions due to its characteristics of low toxicity, high potency, and reversal of MDR. In this study, we develop the artesunate-loaded solid lipid nanoparticles (SLNART) to overcome the poor water solubility and bioavailability of ART, further improving the efficiency of ART on ESCC treatment. Especially mentioned, SLNART is shown to present marked inhibitory effects on ESCC development based on the induction of ferroptosis by two pathways included upregulating TFR to increase Fe2+ ions and inhibiting the AKT/mTOR signaling to downregulate GPX4. Collectively, this study is the first to pave a promising approach for ESCC therapy based on a strategy of developing SLNART to induce ferroptosis by mediating Fe2+ ions and AKT/mTOR signaling.

Unveiling the antibacterial potential and antibiotic-resistance breaker activity of Syzygium jambos (Myrtaceae) towards critical-class priority pathogen Klebsiella isolates

Background: Klebsiella has developed multiple-drug resistance (MDR) to a wide range of medicines, including carbapenems and third generation cephalosporins which are often regarded as the most effective drugs against MDR bacteria. The present study examined the anti-klebsiella, modes of action, and antibiotic-resistance reversal potential of Syzygium jambos (Myrtaceae) leaf (SJL) and bark (SJB) methanol extracts towards a panel of sixteen MDR K. pneumoniae and K. oxytoca strains and clinical isolates. Methods: The anti-klebsiella potential of SJL and SJB was assessed by determining the minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) using broth microdilution. Extracts were tested alone, in combination with an efflux pump inhibitor (PaβN), and in association with conventional antibiotics at their sub-inhibitory concentrations. Effects of SJL were also evaluated on bacterial kinetic growth, H+-ATPase-mediated pump, and cell membrane integrity, using standards. Results: SJL and SJB were shown to have anti-klebsiella action, with MICs ranging from 64 to 2048 g/mL. SJL was found to be more effective, acting on all tested pathogens with 100 ≤ MIC ≤ 2048 µg/mL, indicating considerable to moderate activity and generating bactericidal effects on more than half of the MDR Klebsiella strains investigated. SJL also produced a remarkably active effect (MIC ≤ 100 µg/mL), with MIC of 64 µg/mL against K. pneumoniae KP26. In the presence of PaβN, SJL and SJB activity rose significantly, demonstrating the involvement of active efflux machinery as MDR mechanisms. SJL displayed significant MDR reversal potential, as evidenced by an enhanced efficacy of conventional antibiotics, when in association. The activity of doxycycline and levofloxacin was improved on 100% of studied MDR pathogens. Interestingly, SJL also significantly enhanced the efficacy of the last resort drugs cefixime (cephalosporin) and imipenem (carbapenems) at more than 75% at MIC/2. Exposure of K. pneumoniae KP63 to SJL at 0.5×MIC, MIC, and 2×MIC for 20 h produced a concentration-dependent trend toward greater bacterial killing, extending the latent phase. In addition, SJL showed pronounced inhibition of the H+-ATPase-mediated pump and mildly disrupted the cytoplasmic membrane. Conclusion: This work provides a solid experimental foundation for considering S. jambos leaf extract as a viable treatment option for MDR Klebsiella-related illnesses. Keywords: Antibiotic-resistance modifying agents; efflux pump inhibitor; food plants; Klebsiella infections; multidrug resistance; Syzygium jambos.

Plant-derived natural products and combination therapy in liver cancer.

Liver cancer is one of the malignant cancers globally and seriously endangers human health because of its high morbidity and mortality. Plant-derived natural products have been evaluated as potential anticancer drugs due to low side effects and high anti-tumor efficacy. However, plant-derived natural products also have defects of poor solubility and cumbersome extraction process. In recent years, a growing numbers of plant derived natural products have been used in combination therapy of liver cancer with conventional chemotherapeutic agents, which has improved clinical efficacy through multiple mechanisms, including inhibition of tumor growth, induction of apoptosis, suppression of angiogenesis, enhancement of immunity, reversal of multiple drug resistance and reduction of side effects. The therapeutic effects and mechanisms of plant-derived natural products and combination therapy on liver cancer are reviewed to provide references for developing anti-liver-cancer strategies with high efficacy and low side effects.

Metal-polyphenol-network coated CaCO3 as pH-responsive nanocarriers to enable effective intratumoral penetration and reversal of multidrug resistance for augmented cancer treatments

Construction of multifunctional stimuli-responsive nanotherapeutics enabling improved intratumoral penetration of therapeutics and reversal of multiple-drug resistance (MDR) is potent to achieve effective cancer treatment. Herein, we report a general method to synthesize pH-dissociable calcium carbonate (CaCO3) hollow nanoparticles with amorphous CaCO3 as the template, gallic acid (GA) as the organic ligand, and ferrous ions as the metallic center via a one-pot coordination reaction. The obtained GA–Fe@CaCO3 exhibits high loading efficiencies to both oxidized cisplatin prodrug and doxorubicin, yielding drug loaded GA–Fe@CaCO3 nanotherapeutics featured in pH-responsive size shrinkage, drug release, and Fenton catalytic activity. Compared to nonresponsive GA–Fe@silica nanoparticles prepared with silica nanoparticles as the template, such GA–Fe@CaCO3 confers significantly improved intratumoral penetration capacity. Moreover, both types of drug-loaded GA–Fe@CaCO3 nanotherapeutics exhibit synergistic therapeutic efficacies to corresponding MDR cancer cells because of the GA–Fe mediated intracellular oxidative stress amplification that could reduce the efflux of engulfed drugs by impairing the mitochondrial-mediated production of adenosine triphosphate (ATP). As a result, it is found that the doxorubicin loaded GA–Fe@CaCO3 exhibits superior therapeutic effect towards doxorubicin-resistant 4T1 breast tumors via combined chemodynamic and chemo-therapies. This work highlights the preparation of pH-dissociable CaCO3-based nanotherapeutics to enable effective tumor penetration for enhanced treatment of drug-resistant tumors.

Cholesterol-Containing Nuclease-Resistant siRNA Accumulates in Tumors in a Carrier-free Mode and Silences MDR1 Gene.

Chemical modifications are an effective way to improve the therapeutic properties of small interfering RNAs (siRNAs), making them more resistant to degradation in serum and ensuring their delivery to target cells and tissues. Here, we studied the carrier-free biodistribution and biological activity of a nuclease-resistant anti-MDR1 cholesterol-siRNA conjugate in healthy and tumor-bearing severe combined immune deficiency (SCID) mice. The attachment of cholesterol to siRNA provided its efficient accumulation in the liver and in tumors, and reduced its retention in the kidneys after intravenous and intraperitoneal injection. The major part of cholesterol-siRNA after intramuscular and subcutaneous injections remained in the injection place. Confocal microscopy data demonstrated that cholesterol-siRNA spread deep in the tissue and was present in the cytoplasm of almost all the liver and tumor cells. The reduction of P-glycoprotein level in human KB-8-5 xenograft overexpressing the MDR1 gene by 60% was observed at days 5–6 after injection. Then, its initial level recovered by the eighth day. The data showed that, regardless of the mode of administration (intravenous, intraperitoneal, or peritumoral), cholesterol-siMDR efficiently reduced the P-glycoprotein level in tumors. The designed anti-MDR1 conjugate has potential as an adjuvant therapeutic for the reversal of multiple drug resistance of cancer cells.

Co-delivery of multiple drug resistance inhibitors by polymer/inorganic hybrid nanoparticles to effectively reverse cancer drug resistance

To effectively reverse multiple drug resistance (MDR) in tumor treatments, a functional nano-sized drug delivery system with active targeting function and pH sensitivity was prepared for the co-delivery of multiple drug resistance inhibitors. Buthionine sulfoximine (BSO) to inhibit GSH synthesis and celecoxib (CXB) to down-regulate P-gp expression were co-loaded in polymer/inorganic hybrid nanoparticles to form buthionine sulfoximine/celecoxib@biotin-heparin/heparin/calcium carbonate/calcium phosphate nanoparticles (BSO/CXB@BNP). To investigate the reversal of MDR, the drug resistant cells (MCF-7/ADR) were pretreated by the dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) followed by the treatment of doxorubicin (DOX) loaded nanoparticles (DOX@BNP). The dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) exhibited greatly enhanced efficiency in down-regulation of GSH and P-gp since BSO and CXB had combined effects on the reduction of GSH and P-gp in drug resistant tumor cells. As a result, BSO/CXB@BNP exhibited a significantly improved capability in reversal of MDR compared with mono-inhibitor loaded nanoparticles (CXB@BNP and BSO@BNP). As compared with free drug resistance inhibitors, delivery of drug resistance inhibitors by functional nanocarriers could obviously improve the therapeutic efficiency due to enhanced cellular uptake and increased intracellular drug accumulation. The study on immunostimulatory effects of different treatments showed that BSO/CXB@BNP treatment resulted in the lowest concentration of interleukin 10, a cytokine related to tumor development. These results suggest the nanoparticulate drug delivery platform developed in this study has promising applications in multiple drug delivery to overcome drug resistance in tumor treatments.

Development, Maintenance, and Reversal of Multiple Drug Resistance: At the Crossroads of TFPI1, ABC Transporters, and HIF1.

Early detection and improved therapies for many cancers are enhancing survival rates. Although many cytotoxic therapies are approved for aggressive or metastatic cancer; response rates are low and acquisition of de novo resistance is virtually universal. For decades; chemotherapeutic treatments for cancer have included anthracyclines such as Doxorubicin (DOX); and its use in aggressive tumors appears to remain a viable option; but drug resistance arises against DOX; as for all other classes of compounds. Our recent work suggests the anticoagulant protein Tissue Factor Pathway Inhibitor 1α (TFPI1α) plays a role in driving the development of multiple drug resistance (MDR); but not maintenance; of the MDR state. Other factors; such as the ABC transporter drug efflux pumps MDR-1/P-gp (ABCB1) and BCRP (ABCG2); are required for MDR maintenance; as well as development. The patient population struggling with therapeutic resistance specifically requires novel treatment options to resensitize these tumor cells to therapy. In this review we discuss the development, maintenance, and reversal of MDR as three distinct phases of cancer biology. Possible means to exploit these stages to reverse MDR will be explored. Early molecular detection of MDR cancers before clinical failure has the potential to offer new approaches to fighting MDR cancer.

Modulating cancer multidrug resistance by sertraline in combination with a nanomedicine

Inherent and acquired multiple drug resistance (MDR) to chemotherapeutic drugs is a major obstacle in cancer treatment. The ATP Binding Cassettes (ABC) transporter super family that act as extrusion pumps such as P-glycoprotein and multidrug-resistance-associated-proteins have prominent roles in cancer MDR. One of the most efficient strategies to modulate this active drug efflux from the cells is to physically block the pump proteins and thus change the balance between drug influx and efflux toward an accumulation of drug inside the cell, which eventually cumulates into cell death. MDR modulators (also known as chemosensitizers) were found among drugs approved for non-cancer indications. Yet, toxicity, adverse effects, and poor solubility at doses required for MDR reversal prevent their clinical application. Previous reports have shown that drugs belonging to the selective serotonin reuptake inhibitors (SSRI) family, which are clinically used as antidepressants, can act as effective chemosensitizers both in vitro and in vivo in tumor bearing mouse models. Here, we set out to explore whether sertraline (Zoloft®), a molecule belonging to the SSRI family, can be used as an MDR modulator. Combining sertraline with another FDA approved drug, Doxil® (pegylated liposomal doxorubicin), is expected to enhance the effect of chemotherapy while potentially reducing adverse effects. Our findings reveal that sertraline acts as a pump modulator in cellular models of MDR. In addition, in an aggressive and highly resistant human ovarian xenograft mouse model the use of sertraline in combination with Doxil® generated substantial reduction in tumor progression, with extension of the median survival of tumor-bearing mice. Taken together, our results show that sertraline could act as a clinically relevant cancer MDR inhibitor. Moreover, combining two FDA approved drugs, DOXIL®, which favor the influx of chemotherapy inside the malignant cell with sertraline, which blocks the extrusion pumps, could readily be available for clinical translation in the battle against resistant tumors.

MiR-5000-3p, miR-5009-3P and miR-552: potential microRNA biomarkers of side population cells in colon cancer.

Colon cancer is one of the most common cancers in the world. Multidrug resistance is related to poor prognosis of advanced colon cancer. The side population plays an important role in multiple drug resistance (MDR) of colon cancer. MicroRNA biomarkers of the side population of colon cancer is still unknown. In the present study, we aimed to explore miRNA markers of side population (SP) cells of colon cancer. The side population was sorted by flow cytometry. Cell viability was measured using an MTT assay. MicroRNA profiling analysis was performed to compare microRNA expression levels in the SP cells of colon cancer with levels in the non-SP cells of colon cancer. RT-PCR was applied to verify the result obtained from the microRNA profiling analysis. miR-5000-3p, miR-5009-3P and miR-552 were all found to be upregulated in SP cells of the colon cancer cell lines HCT-15, HT-29 and LoVo. RT-PCR confirmed the result from the microRNA profiling analysis. This implied that miR-5000-3p, miR-5009-3P and miR-552 may be potential microRNA biomarkers of the side population in colon cancer, which may provide new specific targets of the side population for the reversal of MDR of colon cancer.

Rapid and Sensitive UPLC-MS/MS Method for Simultaneous Quantification of Peimine and Peiminine: A Multiple Drug Resistance Reversal Agent of Tumors and their Application to Preliminary Pharmacokinetic Studies in Beagle Dogs

Rapid and Sensitive UPLC-MS/MS Method for Simultaneous Quantification of Peimine and Peiminine: A Multiple Drug Resistance Reversal Agent of Tumors and their Application to Preliminary Pharmacokinetic Studies in Beagle Dogs

Reversal of multiple drug resistance in Escherichia coli by blocking CTX-M through antisense phosphothioate oligodeoxynucleotides

Objective To investigate the effects of antisense phosphothioate oligodeoxynucleotides (AS-ODNs) W086 on drug-resistant gene CTX-M expression in Escherichia coli producing extended-spectrum β-lactamases(ESBLs).Methods AS-ODNs liposome was introduced into the purpose bacteria B052.The total colony forming unit(CFU) was counted.The bacteria growth curve was drawn by microplate reader.The inhibition effects of AS-ODNs on the expressions of drug-resistant gene CTX-M were observed by RT-PCR in B052.The minimal inhibitory concentration(MIC)was determined by fluid dilution method.Results significant growth inhibition of cells treated with W086 was observed as compared with those in cells in control treated bacteria.The number of B052 colonies significantly decreased in all W086 treated groups in a concentration dependent manner (P ＜ 0.05),while CFU of B052 was not influenced in simple liposome group,simple W086 group and controlled chain group.The expression of CTX-M was selectively inhibited.Conclusion Efficiently and specificly blocking expression of CTX-M mRNA,AS-ODNs reverses the multiple drug resistance of B052.It indicates that AS-ODNs provides a new viable strategy to reverse antibiotic resistance problem. Key words: Antisense phosphothioate oligodeoxynucleotides; Extended-spectrum β-lactamases; Escherichia coli; Drug-resistance; Gene expression

Multiple Drug Resistance in Cancer Revisited: The Cancer Stem Cell Hypothesis

The failure to eradicate cancer may be as fundamental as a misidentification of the target. Current therapies succeed at eliminating bulky disease but often miss a tumor reservoir that is the source of disease recurrence and metastasis. Recent advances in the understanding of tissue development and repair cause us to revisit the process of drug resistance as it applies to oncogenesis and tumor heterogeneity. The cancer stem cell hypothesis states that the cancer-initiating cell is a transformed tissue stem cell, which retains the essential property of self-protection through the activity of multiple drug resistance (MDR) transporters. This resting constitutively drug-resistant cell remains at low frequency among a heterogeneous tumor mass. In the context of this hypothesis, the authors review the discovery of MDR transporters in cancer and normal stem cells and the failure of MDR reversal agents to increase the therapeutic index of substrate antineoplastic agents.

Reversal of multiple drug resistance in cholangiocarcinoma by the glutathione S-transferase-pi-specific inhibitor O1-hexadecyl-gamma-glutamyl-S-benzylcysteinyl-D-phenylglycine ethylester.

Cholangiocarcinoma is markedly resistant to chemotherapy and has a dismal prognosis, but its mechanism of drug resistance is unknown. This study examines whether glutathione S-transferase-pi (GSTP1-1) is involved in resistance to anticancer drugs in cholangiocarcinoma and whether GSTP1-1-specific inhibitors can overcome this resistance. First, immunohistochemical examination disclosed strong staining of all our 17 cholangiocarcinoma specimens for GSTP1-1, irrespective of histological type. Transfection of the GSTP1-1 antisense expression vector into a human cholangiocarcinoma cell line (HuCCT1) apparently decreased its intracellular GSTP1-1 concentration, and the sensitivity of transfectants to adriamycin (ADR), cisplatin, and alkylating agents such as melphalan and 4-hydroxyperoxycyclophosphamide (4-HC) was increased significantly, compared with that of mock transfectants. We next synthesized GSTP1-1-specific inhibitors by elongating the carbon chain of the ethylester at the N-terminal of gamma-glutamyl-S-benzylcysteinyl-phenylglycyl diethylester and performed a pharmacokinetic study on them. Of six GSTP1-1 inhibitors tested, O1-hexadecyl-gamma-glutamyl-S-benzylcysteinyl-d-phenylglycine ethylester (C16C2) showed the smallest volume of central compartment and smallest volume of distribution at steady state and the second smallest clearance, being the most effective inhibitor in vivo. The IC50 value of ADR or 4-HC for HuCCT1 cells decreased greater by treatment with C16C2 in a dose-dependent manner, paralleling the decrease in GSTP1-1 activity, than that of ADR or 4-HC alone. The antitumor activity of ADR or cyclophosphamide was clearly enhanced by combination therapy with C16C2 in a xenograft model. In conclusion, our results demonstrated that GSTP1-1 is a resistance factor for anticancer drugs in cholangiocarcinoma and that C16C2, a GSTP1-1-specific inhibitor, is a potent agent against the resistance.

Structure-activity relationship: analyses of p-glycoprotein substrates and inhibitors.

A large number of structurally and functionally diverse compounds act as substrates or modulators of p-glycoprotein (p-gp). Some of them possess multiple drug resistance (MDR)-reversing activity, but only a small number of them have entered clinical study. In order to uncover the factors which exert a significant impact on the interaction between substrates/modulators and p-gp, we have performed structure-activity relationship (SAR) analyses, including molecular modelling, two-dimensional (2D) and three-dimensional (3D) parameter-frame-setting analysis, quantitative structure activity relationship (QSAR) analysis among substrates/modulators, as well as clinically promising MDR-reversing agents. The physicochemical parameters C log P, CMR and all regression equations were derived by using C log P version 4.0 and the latest CQSAR software, respectively. Molecular modelling and all other parameter calculations were performed by using HyperChem version 5.0 program, after geometry optimization and energy minimization using the AM1 semiempirical method. SAR analyses indicate that MDR reversal activity is correlated with the lipophilicity (C log P), molecular weight (log Mw), longest chain (Nlc) of the molecule and the energy of the highest occupied orbital (Ehomo). In addition, the presence of a basic tertiary nitrogen atom in the structure is also an important contributor to p-gp inhibitory activity. Some separation in space is achieved for different subsets of p-gp substrates and inhibitors using Nlc, C log P and Ehomo as three independent parameters in the 3D-parameter-frame setting. A highly effective p-gp modulator candidate should possess a log P value of 2.92 or higher, 18-atom-long or longer molecular axis, and a high Ehomo value, as well as at least one tertiary basic nitrogen atom. The results obtained may be useful in explaining drug-p-gp interactions for different compounds, including drug interactions and the development of new MDR chemosensitizers.

Modulation of vinca-alkaloid induced P-glycoprotein expression by indole-3-carbinol

The over-expression of mdr-1 gene transcript P-glycoprotein (P-gp), responsible for multiple drug resistance, is one of the major obstacles in cancer chemotherapy. In the present study, indole-3-carbinol (I3C), a well-known chemopreventive agent present in cruciferous vegetables, has been evaluated for its potential to modulate the over-expression of P-gp induced by vinblastine or vincristine, which are known inducers of mdr-1 gene. The results revealed that I3C significantly reversed the over-expression of P-gp in vinca-alkaloid induced drug resistance as evident by Western blotting using monoclonal antibody (clone JSB1). Quantization of immunostained tissue sections using image analysis technique revealed that vinblastine/ vincristine induced overexpression of P-gp was effectively reversed by I3C. The present investigation suggests that I3C can significantly inhibit the P-gp over-expression and may have utility as a dietary adjuvant in the treatment of cancer for the reversal of multiple drug resistance.

Reversal of multiple drug resistance in vitro by phosphorothioate oligonucleotides and ribozymes

In the present study we investigated the effectiveness of 14, 15 and 18 nucleotide antisense phosphorothioate oligonucleotides (S-ODNs) directed to four different regions of the published mdr-1 gene sequence to reduce the level of mdr-1 gene product (p170, P-glycoprotein) and its function in the over-expressing cell lines Lo-VoDxR, S180DxR and KBChR8-5. The highest efficiency in reduction of multiple drug resistance was obtained at a concentration of 2 microM. In proliferation assays a growth reduction of 50% was observed after exposure of doxorubicin-resistant cells to S-ODN3. p170 protein expression of the resistant cell line LoVoDxR was reduced to the level of the sensitive cell line LoVo as shown by Western blot analysis. S-ODN3 reduced the ID50 of the two human cell lines up to 60% (LoVoDxR) and 21% (KBChR8-5), respectively, but showed no effect in the murine cell line S180DxR. In contrast, S-ODN1 was most effective in the murine system (67% reduction of the ID50), less effective in LoVoDxR (34%) and exhibited no effect in cell line KBChR8-5. Based on the results with the antisense oligonucleotides, a ribozyme directed against the mRNA target region of S-ODN3 was designed. This ribozyme was able to reduce the mdr-1 mRNA in total RNA preparations from cell line LoVoDxR up to 80% after an incubation time of 6 h in the presence of 10 mM MgCl2 at pH 7.5. A modified ribozyme was investigated in cell culture and reduced chemo-resistance of the resistant cell line LoVoDxR and ex vivo cultured blasts of acute myeloid leukemia patients up to 50%.