Enhanced in vitro and in vivo therapeutic efficacy of codrug-loaded nanoparticles against liver cancer

Advances in nano-preparations for improving tetrandrine solubility and bioavailability

Tetrandrine (TET) is a natural bis-benzylisoquinoline alkaloid isolated from Stephania species with a wide range of biological and pharmacologic activities; it mainly serves as an anti-inflammatory agent or antitumor adjuvant in clinical applications. However, limitations such as prominent hydrophobicity, severe off-target toxicity, and low absorption result in suboptimal therapeutic outcomes preventing its widespread adoption. Nanoparticles have proven to be efficient devices for targeted drug delivery since drug-carrying nanoparticles can be passively transported to the tumor site by the enhanced permeability and retention (EPR) effects, thus securing a niche in cancer therapies. Great progress has been made in nanocarrier construction for TET delivery due to their outstanding advantages such as increased water-solubility, improved biodistribution and blood circulation, reduced off-target irritation, and combinational therapy. Herein, we systematically reviewed the latest advancements in TET-loaded nanoparticles and their respective features with the expectation of providing perspective and guidelines for future research and potential applications of TET.

Drug repurposing a compelling cancer strategy with bottomless opportunities: Recent advancements in computational methods and molecular mechanisms

Drug discovery has customarily focused on a de novo design approach, which is extremely expensive and takes several years to evolve before reaching the market. Discovering novel therapeutic benefits for the current drugs could contribute to new treatment alternatives for individuals with complex medical demands that are safe, inexpensive, and timely. In this consequence, when pharmaceutically yield and oncology drug efficacy appear to have hit a stalemate, drug repurposing is a fascinating method for improving cancer treatment. This review gathered about how in silico drug repurposing offers the opportunity to quickly increase the anticancer drug arsenal and, more importantly, overcome some of the limits of existing cancer therapies against both old and new therapeutic targets in oncology. The ancient nononcology compounds' innovative potential targets and important signaling pathways in cancer therapy are also discussed. This review also includes many plant-derived chemical compounds that have shown potential anticancer properties in recent years. Here, we have also tried to bring the spotlight on the new mechanisms to support clinical research, which may become increasingly essential in the future; at the same time, the unsolved or failed clinical trial study should be reinvestigated further based on the techniques and information provided. These encouraging findings, combined together, will through new insight on repurposing more non-oncology drugs for the treatment of cancer.

Progress on structural modification of Tetrandrine with wide range of pharmacological activities

Tetrandrine (Tet), derived from the traditional Chinese herb Fangji, is a class of natural alkaloids with the structure of bisbenzylisoquinoline, which has a wide range of physiological activities and significant pharmacfological effects. However, studies and clinical applications have revealed a series of drawbacks such as its poor water solubility, low bioavailability, and the fact that it can be toxic to humans. The results of many researchers have confirmed that chemical structural modifications and nanocarrier delivery can address the limited application of Tet and improve its efficacy. In this paper, we summarize the anti-tumor efficacy and mechanism of action, anti-inflammatory efficacy and mechanism of action, and clinical applications of Tet, and describe the progress of Tet based on chemical structure modification and nanocarrier delivery, aiming to explore more diverse structures to improve the pharmacological activity of Tet and provide ideas to meet clinical needs.

Long noncoding RNA LEF1-AS1 acts as a microRNA-10a-5p regulator to enhance MSI1 expression and promote chemoresistance in hepatocellular carcinoma cells through activating AKT signaling pathway

Long noncoding RNAs (lncRNAs) contribute to the development of hepatocellular carcinoma (HCC), which could regulate various HCC biological characteristics. Here, the study seeks to investigate the role of lncRNA LEF1-AS1 in HCC cell chemoresistance by regulating microRNA (miR)-10a-5p and Musashi1 (MSI1). The microarray-based analysis was employed to identify the HCC-related lncRNA-miRNA-gene regulatory network. Expression patterns of LEF1-AS1, miR-10a-5p, and MSI1 in the HCC cell lines, tissues were accessed by means of reverse transcription-quantitative polymerase chain reaction. Next, the interaction among LEF1-AS1, miR-10a-5p, and MSI1 in HCC was accessed by bioinformatics and dual-luciferase reporter gene assay. Then, the cell line resistant to cisplatin was established, which was then treated with sh/oe-lncRNA LEF1-AS1, miR-10a-5p-mimic, and oe/sh-MSI1 vectors alone or in combination. Afterward, the effect of LEF1-AS1, miR-10a-5p, and MSI1 on HCC cell chemoresistance, proliferation, and apoptosis was assessed. At last, in vivo experiments confirmed the role of MSI1 in tumor growth and chemoresistance in HCC. LEF1-AS1 might potentially affect the growth and chemoresistance of HCC cells by regulating miR-10a-5p and MSI1. LEF1-AS1 and MSI1 expression patterns were elevated, while miR-10a-5p was repressed in HCC tissues and cell lines. LEF1-AS1 combined to miR-10a-5p and regulated MSI1, thereby activating the protein kinase B (AKT) signaling pathway. Knockdown of LEF1-AS1 and MSI1 or elevation of miR-10a-5p compromised the proliferation of Huh7 cell line resistant to DDP and promoted its chemosensitivity and apoptosis. At last, these in vitro findings were also confirmed in vivo. Our results unraveled LEF1-AS1 acts as a miR-10a-5p modulator to promote chemoresistance of HCC cells by stimulating MSI1 and activating the AKT signaling pathway, which might provide a novel therapeutic target for HCC.

Dual variable of drug loaded micelles in both particle and electrical charge on gastric cancer treatment

Gastric cancer is a malignant tumour characterised by the uncontrolled cell growth. The incidence and mortality of gastric cancer remain high for the invasion and metastasis. We are urgently seeking a risk-free and effective treatment strategy for gastric cancer. In this study, paclitaxel and tetrandrine were encapsulated in the inner core of micelles, and DSPE-PEG₂₀₀₀-CPP and HA were modified on the micellar surface. HA/CPP modified paclitaxel plus tetrandrine micelles had a suitable particle size (90 nm) for permeating tumour tissue. The zeta potential of the targeting micelles was 8.37 mV after hydrolysis by HAase solution. Results of in vitro experiments indicated that HA/CPP modified paclitaxel plus tetrandrine micelles + HAase could enhance the intracellular uptake, inhibit the formation of neovascularization, block the process of EMT and destroy the invasion and metastasis. In vivo assays indicated that HA/CPP modified paclitaxel plus tetrandrine micelles could be selectively accumulated into tumour sites and exhibited the strong antitumor activity with negligible toxicity. These results suggested that HA/CPP modified paclitaxel plus tetrandrine micelles might provide a new strategy for treating gastric cancer.

Novel "Carrier-Free" Nanofiber Codelivery Systems with the Synergistic Antitumor Effect of Paclitaxel and Tetrandrine through the Enhancement of Mitochondrial Apoptosis

Paclitaxel (Ptx), a type of microtubule depolymerization inhibitor, is one of the main components in gastric cancer chemotherapy. Some studies have demonstrated that tetrandrine (Tet), a bisbenzylisoquinoline alkaloid, has potential antitumor effects in several cancers. Aside from the direct anticancer effect, Tet is proved to synergistically enhance the antitumor effect of Ptx in gastric cancer. However, the application of the combinational strategy is limited by the poor solubility of both drugs. Nanodrug delivery systems including polymeric nanoparticles, self-assembled nanofibers, hydrogels, etc., hold the potential to meet the need. Here, a novel supramolecular nanomaterial, based on the concept of "carrier-free nanodrugs", is reported as a feasible platform for synergistic drug delivery. Ptx-SA-RGD is obtained through the conjugation of Ptx and the tumor-specific peptide RGD (arginine-glycine-aspartic acid) with succinic acid (SA) as a linker. Ptx-SA-RGD could self-assemble into Ptx nanofibers (P-NFs) with high drug-loading efficiency. Tet was then encapsulated into P-NFs to acquire novel Ptx and Tet coloaded self-assembled nanofibers (P/T-NFs). The uptake study shows the dynamic internalization of P/T-NFs by the gastric cancer cell line MGC-803. P/T-NFs significantly triggered the accumulation of reactive oxygen species (ROS) in gastric cancer cells MGC803 and further decreased the mitochondrial membrane potential, which led to the induction of mitochondrial apoptosis with superior cytotoxicity against free drugs. Moreover, P/T-NFs suppressed the expressions of p-STAT3 and p-JAK, initiated cytochrome-C release, and promoted caspase protein expression. Furthermore, P/T-NFs demonstrated the strongest tumor-delaying effect as well as the lowest toxicity. Therefore, self-assembled nanofibers of P/T-NFs demonstrated an increase of the mitochondrial apoptosis level and a stronger antitumor effect both in vitro and in vivo, which could be a potential way to enhance the clinical efficacy and reduce the side-effects of Ptx in gastric cancer.

Superior antitumor effect of self-assembly supramolecular paclitaxel nanoparticles

Carrier-free paclitaxel nanoparticles with higher drug loading efficiency, less non-specific toxicity and more stable and durable antitumor effect of Ptx.

RIPL peptide-conjugated nanostructured lipid carriers for enhanced intracellular drug delivery to hepsin-expressing cancer cells

Background

To facilitate selective and enhanced drug delivery to hepsin (Hpn)-expressing cancer cells, RIPL peptide (IPLVVPLRRRRRRRRC, 16-mer)-conjugated nanostructured lipid carriers (RIPL-NLCs) were developed.

Methods

NLCs were prepared using a solvent emulsification-evaporation method and the RIPL peptide was conjugated to the maleimide-derivatized NLCs via the thiol-maleimide reaction. Employing a fluorescent probe (DiI), in vitro target-selective intracellular uptake behaviors were observed using fluorescence microscopy and flow cytometry. Separately, docetaxel (DTX) was encapsulated by pre-loading technique, then cytotoxicity and drug release were evaluated. In vivo antitumor efficacy was investigated in BALB/c nude mice with SKOV3 cell tumors after intratumoral injections of different DTX formulations at a dose equivalent to 10 mg/kg DTX.

Results

RIPL-NLCs showed positively charged nanodispersion, whereas NLCs were negatively charged. DTX was successfully encapsulated with an encapsulation efficiency and drug loading capacity of 95-98% and 44-46 µg/mg, respectively. DTX release was diffusion-controlled, revealing the best fit to the Higuchi equation. Cellular uptake of DiI-loaded RIPL-NLCs was 8.3- and 6.2-fold higher than that of DiI-loaded NLCs, in Hpn(+) SKOV3 and LNCaP cells, respectively. The translocation of RIPL-NLCs into SKOV3 cells was time-dependent with internalization within 1 h and distribution throughout the cytoplasm after 2 h. DTX-loaded RIPL-NLCs (DTX-RIPL-NLCs) revealed dose-dependent in vitro cytotoxicity, while drug-free formulations were non-cytotoxic. In SKOV3-bearing xenograft mouse model, DTX-RIPL-NLCs significantly inhibited tumor growth: the inhibition ratios of the DTX solution-treated and DTX-RIPL-NLC-treated groups were 61.4% and 91.2%, respectively, compared to those of the saline-treated group (control).

Conclusion

RIPL-NLCs are good candidates for Hpn-selective drug targeting with a high loading capacity of hydrophobic drug molecules.

Tetrandrine, a Chinese plant-derived alkaloid, is a potential candidate for cancer chemotherapy

Cancer is a disease caused by the abnormal proliferation and differentiation of cells governed by tumorigenic factors. Chemotherapy is one of the major cancer treatment strategies, and it functions by targeting the physiological capabilities of cancer cells, including sustained proliferation and angiogenesis, the evasion of programmed cell death, tissue invasion and metastasis. Remarkably, natural products have garnered increased attention in the chemotherapy drug discovery field because they are biologically friendly and have high therapeutic effects. Tetrandrine, isolated from the root of Stephania tetrandra S Moore, is a traditional Chinese clinical agent for silicosis, autoimmune disorders, inflammatory pulmonary diseases, cardiovascular diseases and hypertension. Recently, the novel anti-tumor effects of tetrandrine have been widely investigated. More impressive is that tetrandrine affects multiple biological activities of cancer cells, including the inhibition of proliferation, angiogenesis, migration, and invasion; the induction of apoptosis and autophagy; the reversal of multidrug resistance (MDR); and the enhancement of radiation sensitization. This review focuses on introducing the latest information about the anti-tumor effects of tetrandrine on various cancers and its underlying mechanism. Moreover, we discuss the nanoparticle delivery system being developed for tetrandrine and the anti-tumor effects of other bisbenzylisoquinoline alkaloid derivatives on cancer cells. All current evidence demonstrates that tetrandrine is a promising candidate as a cancer chemotherapeutic.

Tetrandrine and cancer - An overview on the molecular approach

Tetrandrine has been known in the treatment of tuberculosis, hyperglycemia, negative ionotropic and chronotropic effects on myocardium, malaria, cancer and fever since years together. It has been known that, tetrandrine could modulate multiple signaling molecules such as kinases of cell cycle and rat sarcoma (RAS) pathway along with proteins of tumor suppressor genes, autophagy related, β-catenins, caspases, and death receptors. Moreover, tetrandrine exhibited reversal of drug resistance by modulating P-glyco protein (P-gp) expression levels in different cancers which is an added advantage of this compound compared to other chemotherapy drugs. Though, bioavailability of tetrandrine is a limiting factor, the anticancer activity was observed in animal models without changing any pharmacokinetic parameters. In the present review, role of tetrandrine as kinase inhibitor, inducer of autophagy and caspase pathways and suppressor of RAS mediated cell proliferation were discussed along with inhibition of angiogenesis. It has also been discussed that how tetrandrine potentiate anticancer effect in different types of cancers by modulating multidrug resistance under in vitro and in vivo trials including the available literature on the clinical trials.

Metformin enhances the chemosensitivity of hepatocarcinoma cells to cisplatin through AMPK pathway

This study investigated the effect of metformin on chemosensitivity of hepatocarcinoma cells to cisplatin and the possible mechanism. HepG2 and Huh-7 hepatoma cells were treated with cisplatin at concentrations of 0, 2, 4, 6, 8 and 10 µM for 48 h. Proliferation of HepG2 and Huh-7 hepatoma cells were detected by MTT assay. Apoptosis of hepatocellular carcinoma cells was detected by flow cytometry. Western blot analysis was used to detect the expression of 5-monophosphate-activated protein kinase (AMPK) and p-AMPK protein. Proliferative activity of HepG2 and Huh-7 cells decreased with the increase of cisplatin concentration. After adding metformin, proliferation ability of hepatocarcinoma cells was significantly reduced. Apoptosis rate of the metformin was significantly higher than that of the control group, and apoptosis rate of the cisplatin + metformin was significantly higher than that of the cisplatin group. There was no significant difference in expression level of AMPK protein found between control, metformin, cisplatin and cisplatin + metformin group. Compared with the control, ratio of p-AMPK/AMPK in metformin group was increased, and ratio of p-AMPK/AMPK in cisplatin + metformin was significantly higher than that in cisplatin group. Activity of cells in cisplatin + metformin + compound C (AMPK pathway blocker) group was significantly higher than that of cisplatin + metformin, while apoptosis of cells in cisplatin + metformin + compound C (AMPK pathway blocker) was significantly lower than that of cisplatin + metformin group. In conclusion, metformin can inhibit the proliferation, promote apoptosis and enhance the chemosensitivity of hepatocarcinoma cells to cisplatin through AMPK pathway.

A Benzylideneacetophenone Derivative Induces Apoptosis of Radiation-Resistant Human Breast Cancer Cells via Oxidative Stress

Benzylideneacetophenone derivative (1E)-1-(4-hydroxy-3-methoxyphenyl) hept-1-en-3-one (JC3) elicited cytotoxic effects on MDA-MB 231 human breast cancer cells-radiation resistant cells (MDA-MB 231-RR), in a dose-dependent manner, with an IC₅₀ value of 6 μM JC3. JC3-mediated apoptosis was confirmed by increase in sub-G1 cell population. JC3 disrupted the mitochondrial membrane potential, and reduced expression of anti-apoptotic B cell lymphoma-2 protein, whereas it increased expression of pro-apoptotic Bcl-2-associated X protein, leading to the cleavage of caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In addition, JC3 activated mitogen-activated protein kinases, and specific inhibitors of these kinases abrogated the JC3-induced increase in apoptotic bodies. JC3 increased the level of intracellular reactive oxygen species and enhanced oxidative macromolecular damage via lipid peroxidation, protein carbonylation, and DNA strand breakage. Considering these findings, JC3 is an effective therapy against radiation-resistant human breast cancer cells.

Superior antitumor effect of extremely high drug loading self-assembled paclitaxel nanofibers

Recent studies focused on the nanodelivery system of paclitaxel (Ptx) to overcome the poor solubility and hypersensitivity of Ptx caused by the application of Cremophor EL as a solvent. Although many studies use different types of polymers as carriers to prepare Ptx-loaded polymeric nanoparticles, the relatively low loading efficiency of Ptx-loaded polymeric nanoparticles significantly limits its application. Here, we design and synthesize a simple conjugation of Ptx and succinic acid (Ptx-SA), which can self-assemble into nanofibers and become "carrier-free" with Ptx as the drug carrier. The highest loading efficiency of Ptx is 89.5% with a controlled release pattern. The cellular uptake study indicates the internalization of Ptx-SA nanofibers by A549 cells. The in vitro cytotoxicity test results indicate that Ptx-SA nanofibers were much more effective in inhibiting the proliferation of A549 cells than free Ptx, particularly at the lower working concentration. The clonogenic assay shows the enhanced effect of Ptx-SA in ameliorating the clonogenic abilities of A549 cells compared with the equivalent dose of free Ptx. Moreover, Ptx-SA significantly attenuates the expression of p-Akt and increases the expression of cleaved PARP and Caspase-3 compared to the equivalent dose of free Ptx, which demonstrates the enhanced apoptosis-inducing effect of Ptx-SA. The animal study demonstrates the superior antitumor effect of Ptx-SA compared to free Ptx. Therefore, the conjugation of Ptx with SA enables the self-assembly of Ptx-loaded nanofibers with stronger in vitro and in vivo antitumor effects, which is a promising method to improve the therapeutic efficacy of Ptx in treating lung cancer.

Inhibition of TrxR2 suppressed NSCLC cell proliferation, metabolism and induced cell apoptosis through decreasing antioxidant activity

AIMS

This study aims to analyze the effect of thioredoxin reductase 2 (TrxR2) on lung cancer cell proliferation, apoptosis, invasion and migration in vitro.

MAIN METHODS

Real-time PCR was used to measure the expression of TrxR2 in NSCLC tumor tissues. After pAd-TrxR2 or shRNA-TrxR2 was transfected into A549 or NCI-H1299 cells, the cell proliferation was measured by CCK-8 method; cell apoptosis was measured by flow cytometry; cell invasion and migration was measured by Transwell method. The production of ROS was measured by DCFH-DA method; the activity of SOD, CAT and GSH-Px was measured by relative ELISA kit.

KEY FINDINGS

The results showed that TrxR2 was up-regulated in NSCLC tumor tissues. Inhibition of TrxR2 suppressed NSCLC cell proliferation and induced apoptosis, and inhibited cell invasion and migration. However, overexpression of TrxR2 showed the opposite effect. Furthermore, when cells were transfected with shRNA-TrxR2, the production of ROS was significantly increased, and SOD, CAT and GSH-Px activity was decreased. Conversely, pAd-TrxR2 transfection showed the opposite effect.

SIGNIFICANCE

Taken together, our results suggest that TrxR2 acts as an oncogenic gene in the context of lung cancer progression. The inhibition of TrxR2 suppressed lung cancer cell proliferation, invasion and migration and induced cell apoptosis by inducing ROS production and decreasing antioxidant activity. TrxR2 may be a potential target for NSCLC treatment.

A microalga, Euglena tuba induces apoptosis and suppresses metastasis in human lung and breast carcinoma cells through ROS-mediated regulation of MAPKs

Background

Euglena tuba, a microalga, is known for its excellent antioxidant and iron-chelation activities; however its anticancer efficacies have not been reported yet. This study investigates the antitumor and antimetastatic activities of 70 % methanolic extract of Euglena tuba (ETME) against human lung (A549) and breast cancer (MCF-7) cells in vitro. Moreover, we had examined ETME’s role in inducing intracellular ROS with the regulation of antioxidants and MAPK pathway.

Methods

Anticancer activity of ETME was thoroughly studied using flow cytometry, confocal microscopy and western blotting; along with various biochemical assays for analysing ROS-induced regulation of antioxidant enzymes. Inhibition of invasion and migration of malignant cells by ETME were investigated by wound healing and zymographic studies. DNA–Protein interaction with ETME was also studied.

Results

ETME inhibited the growth of both A549 (IC₅₀ 92.14 µg/ml) and MCF-7 cells (IC₅₀ 50.27 µg/ml) by inducing apoptosis, while remained non-toxic against nomral WI-38 cells (IC₅₀ 911.43 µg/ml). ETME treatment resulted in increasing Bax/Bcl-2 ratio, BID truncation and activation of caspase cascade. This ultimately leads to PARP degradation and apoptosis through the intrinsic and extrinsic pathway in both A549 and MCF-7 cells. Wound healing and gelatin zymography studies revealed that ETME significantly inhibited the invasion and migration of both A549 and MCF-7 cells dose-dependently through the downregulation of MMP-9. Further investigations showed that ETME selectively induces intracellular ROS, regulated the levels of intracellular antioxidants and suppresses the activation of ERK1/2, JNK, P38 mitogen-activated protein kinase pathways in both type of malignant cells. Further DNA and protein binding studies revealed that ETME strongly interact with DNA as well as protein attributing the possibilities of presence of components which are targeting the macromolecules in cancer cells. Moreover, when the identified compounds from ETME were examined for their cytotoxicities individually, it was found that they lost their specificities towards cancer cells and also attacked normal cells.

Conclusions

Our study suggests that ETME retards the growth of both lung and breast cancer cells, in vitro, through multivariate mechanisms, proving its candidature for the development of better and safer drugs against these cancers.

Efficient antitumor effect of co-drug-loaded nanoparticles with gelatin hydrogel by local implantation

Tetrandrine (Tet) could enhance the antitumor effect of Paclitaxel (Ptx) by increasing intracellular Reactive Oxygen Species (ROS) levels, which leads to the possibility of co-delivery of both drugs for synergistic antitumor effect. In the current study, we reported an efficient, local therapeutic strategy employing effective Tet and Ptx delivery with a nanoparticle-loaded gelatin system. Tet- and Ptx co-loaded mPEG-PCL nanoparticles (P/T-NPs) were encapsulated into the physically cross-linked gelatin hydrogel and then implanted on the tumor site for continuous drug release. The drug-loaded gelatin hydrogel underwent a phase change when the temperature slowly increased. In vitro study showed that Tet/Ptx-loaded PEG-b-PCL nanoparticles encapsulated within a gelatin hydrogel (P/T-NPs-Gelatin) inhibited the growth and invasive ability of BGC-823 cells more effectively than the combination of free drugs or P/T-NPs. In vivo study validated the therapeutic potential of P/T-NPs-Gelatin. P/T-NPs-Gelatin significantly inhibited the activation of p-Akt and the downstream anti-apoptotic Bcl-2 protein and also inducing the activation of pro-apoptotic Bax protein. Moreover, the molecular-modulating effect of P/T-NPs-Gelatin on related proteins varied slightly under the influence of NAC, which was supported by the observations of the tumor volumes and weights. Based on these findings, local implantation of P/T-NPs-Gelatin may be a promising therapeutic strategy for the treatment of gastric cancer.

Tetrandrine--A molecule of wide bioactivity

Stephania tetrandra and other related species of Menispermaceae form the major source of the bisbenzylisoquinoline alkaloid - tetrandrine. The plant is extensively referenced in the Chinese Pharmacopoeia for its use in the Chinese medicinal system as an analgesic and diuretic agent and also in the treatment of hypertension and various other ailments, including asthma, tuberculosis, dysentery, hyperglycemia, malaria, cancer and fever. Tetrandrine, well-known to act as a calcium channel blocker, has been tested in clinical trials and found effective against silicosis, hypertension, inflammation and lung cancer without any toxicity. Recently, the efficacy of tetrandrine was tested against Mycobaterium tuberculosis, Candida albicans, Plasmodium falciparum and Ebola virus. Tetrandrine's pharmacological property has been proved to be through its action on different signalling pathways like reactive oxygen species, enhanced autophagic flux, reversal of multi drug resistance, caspase pathway, cell cycle arrest and by modification of calcium channels. The present review summarises current knowledge on the synthesis, distribution, extraction, structural elucidation, pharmacological properties and the mechanism of action of tetrandrine. Future perspectives in the clinical use of tetrandrine as a drug are also considered.

Psoralen reverses the P-glycoprotein-mediated multidrug resistance in human breast cancer MCF-7/ADR cells

The resistance of cancer to chemotherapeutic agents is a major obstacle during chemotherapy. Clinical multidrug resistance (MDR) is commonly mediated by membrane drug efflux pumps, including ATP‑binding cassette subfamily B member 1, also termed P-glycoprotein (P-gp). P-gp is a membrane transporter encoded by the MDR1 gene. The current study aimed to investigate the impact of psoralen on the expression and function of P‑gp. The 10% inhibitory concentration (IC10) of psoralen, and its capacity to reduce MDR in adriamycin (ADR)‑resistant MCF‑7/ADR cells were determined using MTT assay. The ability of psoralen to modulate the transport activity of P‑gp in MCF‑7/ADR cells was evaluated by measuring the accumulation and efflux of rhodamine 123 (Rh 123) and adriamycin with flow cytometry. The present study evaluated the mRNA level of MDR1 in MCF‑7 and MCF‑7/ADR cells treated with psoralen using reverse transcription-quantitative polymerase chain reaction. The protein expression level of P‑gp was examined by western blot analysis. The current study demonstrated that the IC10 of psoralen in MCF‑7/ADR cells was 8 µg/ml. At 8 µg/ml, psoralen reduced MDR and the sensitivity of the MCF‑7/ADR cells to ADR compared with untreated cells. Additionally, psoralen significantly increased the intracellular accumulation of ADR and Rh 123. However, the IC10 of psoralen did not affect the protein expression levels of P‑gp or mRNA levels of MDR1 (P>0.05). Psoralen reduces MDR by inhibiting the efflux function of P‑gp, which may be important for increasing the efficiency of chemotherapy and improving the clinical protocols aiming to reverse P-gp-mediated MDR.

Tumor pH(e)-triggered charge-reversal and redox-responsive nanoparticles for docetaxel delivery in hepatocellular carcinoma treatment

The insufficient cellular uptake of nanocarriers and their slow drug release have become major obstacles for achieving satisfactory anticancer outcomes in nano-medicine therapy. Because of the slightly acidic extracellular environment (pHe≈ 6.5) and a higher glutathione (GSH) concentration (approximately 10 mM) in tumor tissue/cells, we firstly designed a novel d-α-tocopheryl polyethylene glycol 1000-poly(β-amino ester) block copolymer containing disulfide linkages (TPSS). TPSS nanoparticles (NPs) with pH- and redox-sensitive behaviors were developed for on-demand delivery of docetaxel (DTX) in hepatocellular carcinoma. DTX/TPSS NPs exhibited sensitive surface charge reversal from -47.6 ± 2.5 mV to +22.5 ± 3.2 mV when the pH decreased from 7.4 to 6.5, to simulate the pHe. Meanwhile, anabatic drug release of DTX/TPSS NPs was observed in PBS buffer (pH 6.5, 10 mM GSH). Due to the synergism between the pHe-triggered charge reversal and the redox-triggered drug release, enhanced drug uptake and anticancer efficacy were observed in HepG2 and SMMC 7721 cells treated with DTX/TPSS NPs. The positively charged NPs exhibited a stronger inhibitory effect on cell proliferation, promoted cell cycle arrest in the G2/M phase, and increased the rate of apoptosis. More importantly, based on the higher tumor accumulation of TPSS vehicles in vivo, a significant suppression of tumor growth, but without side-effects, was observed when DTX/TPSS NPs were injected intravenously into HepG2 xenograft tumor-bearing mice. Collectively, these results demonstrate that the newly developed dual-functional TPSS copolymer may be utilized as a drug delivery system for anticancer therapy.

Lactoferrin-modified PEGylated liposomes loaded with doxorubicin for targeting delivery to hepatocellular carcinoma

Lactoferrin (Lf) is a potential-targeting ligand for hepatocellular carcinoma (HCC) cells because of its specific binding with asialoglycoprotein receptor (ASGPR). In this present work, a doxorubicin (DOX)-loaded, Lf-modified, polyethylene glycol (PEG)ylated liposome (Lf-PLS) system was developed, and its targeting effect and antitumor efficacy to HCC was also explored. The DOX-loaded Lf-PLS system had spherical or oval vesicles, with mean particle size approximately 100 nm, and had an encapsulation efficiency of 97%. The confocal microscopy and flow cytometry indicated that the cellular uptake of Lf-PLS was significantly higher than that of PEGylated liposome (PLS) in ASGPR-positive cells (P<0.05) but not in ASGPR-negative cells (P>0.05). Cytotoxicity assay by MTT demonstrated that DOX-loaded Lf-PLS showed significantly stronger antiproliferative effects on ASGPR-positive HCC cells than did PLS without the Lf modification (P<0.05). The in vivo antitumor studies on male BALB/c nude mice bearing HepG2 xenografts demonstrated that DOX-loaded Lf-PLS had significantly stronger antitumor efficacy compared with PLS (P<0.05) and free DOX (P<0.05). All these results demonstrated that a DOX-loaded Lf-PLS might have great potential application for HCC-targeting therapy.

Deguelin induces the apoptosis of lung cancer cells through regulating a ROS driven Akt pathway

Background

Duguelin is a rotenoid extracted from plants and has potent antitumor effects in vitro and in vivo. However, the mechanism underlying the antitumor effect remains unclear. Our preliminary study showed that Deguelin is effective to stimulate the generation of Reactive Oxygen Species (ROS). In the current study, we evaluated the in vitro cytotoxicity of Deguelin against lung cancer cells and studied whether a ROS scavenger, N-acetyl-cysteine (NAC), can reverse the inhibitory effect of Deguelin.

Results

We showed that the dose-dependent apoptotic inducing effect of Deguelin could be partially reversed by the co-administration of NAC. Moreover, Deguelin reduced the phosphorylation of Akt protein and induced the apoptotic protein Caspase-3 in a dose-dependent manner. Co-treatment with NAC partially attenuated this effect and rescued some cells from apoptosis.

Conclusion

Deguelin induces the apoptosis of cancer cells through a ROS driven Akt pathway, which could translate into a promising therapeutic for lung cancer.

An efficient Trojan delivery of tetrandrine by poly(N-vinylpyrrolidone)-block-poly(ε-caprolactone) (PVP-b-PCL) nanoparticles shows enhanced apoptotic induction of lung cancer cells and inhibition of its migration and invasion

Earlier studies have demonstrated the promising antitumor effect of tetrandrine (Tet) against a series of cancers. However, the poor solubility of Tet limits its application, while its hydrophobicity makes Tet a potential model drug for nanodelivery systems. We report on a simple way of preparing drug-loaded nanoparticles formed by amphiphilic poly(N-vinylpyrrolidone)-block-poly(ε-caprolactone) (PVP-b-PCL) copolymers with Tet as a model drug. The mean diameters of Tet-loaded PVP-b-PCL nanoparticles (Tet-NPs) were between 110 nm and 125 nm with a negative zeta potential slightly below 0 mV. Tet was incorporated into PVP-b-PCL nanoparticles with high loading efficiency. Different feeding ratios showed different influences on sizes, zeta potentials, and the drug loading efficiencies of Tet-NPs. An in vitro release study shows the sustained release pattern of Tet-NPs. It is shown that the uptake of Tet-NPs is mainly mediated by the endocytosis of nanoparticles, which is more efficient than the filtration of free Tet. Further experiments including fluorescence activated cell sorting and Western blotting indicated that this Trojan strategy of delivering Tet in PVP-b-PCL nanoparticles via endocytosis leads to enhanced induction of apoptosis in the non-small cell lung cancer cell A549 line; enhanced apoptosis is achieved by inhibiting the expression of anti-apoptotic Bcl-2 and Bcl-xL proteins. Moreover, Tet-NPs more efficiently inhibit the ability of cell migration and invasion than free Tet by down-regulating matrix metalloproteinases (MMP)-2 and MMP-9, as well as up-regulating tissue inhibitor of MMP-3 (TIMP-3). Therefore, data from this study not only confirms the potential of Tet in treating lung cancer but also offers an effective way of improving the anticancer efficiency of Tet by nanodrug delivery systems.

Efficient hepatic delivery of drugs: novel strategies and their significance

Liver is a vital organ responsible for plethora of functions including detoxification, protein synthesis, and the production of biochemicals necessary for the sustenance of life. Therefore, patients with chronic liver diseases such as viral hepatitis, liver cirrhosis, and hepatocellular carcinoma need immediate attention to sustain life and as a result are often exposed to the prolonged treatment with drugs/herbal medications. Lack of site-specific delivery of these medications to the hepatocytes/nonparenchymal cells and adverse effects associated with their off-target interactions limit their continuous use. This calls for the development and fabrication of targeted delivery systems which can deliver the drug payload at the desired site of action for defined period of time. The primary aim of drug targeting is to manipulate the whole body distribution of drugs, that is, to prevent distribution to non-target cells and concomitantly increase the drug concentration at the targeted site. Carrier molecules are designed for their selective cellular uptake, taking advantage of specific receptors or binding sites present on the surface membrane of the target cell. In this review, various aspects of liver targeting of drug molecules and herbal medications have been discussed which elucidate the importance of delivering the drugs/herbal medications at their desired site of action.