Synergistic effects of pemetrexed and amrubicin in non-small cell lung cancer cell lines: Potential for combination therapy

Therapeutic applications of carbohydrate-based compounds: a sweet solution for medical advancement

Carbohydrates, one of the most abundant biomolecules found in nature, have been seen traditionally as a dietary component of foods. Recent findings, however, have unveiled their medicinal potential in the form of carbohydrates-derived drugs. Their remarkable structural diversity, high optical purity, bioavailability, low toxicity and the presence of multiple functional groups have positioned them as a valuable scaffold and an exciting frontier in contemporary therapeutics. At present, more than 170 carbohydrates-based therapeutics have been granted approval by varying regulatory agencies such as United States Food and Drug Administration (FDA), Japan Pharmaceuticals and Medical Devices Agency (PMDA), Chinese National Medical Products Administration (NMPA), and the European Medicines Agency (EMA). This article explores an overview of the fascinating potential and impact of carbohydrate-derived compounds as pharmacological agents and drug delivery vehicles.

Carbohydrate-based drugs launched during 2000-2021

Carbohydrates are fundamental molecules involved in nearly all aspects of lives, such as being involved in formating the genetic and energy materials, supporting the structure of organisms, constituting invasion and host defense systems, and forming antibiotics secondary metabolites. The naturally occurring carbohydrates and their derivatives have been extensively studied as therapeutic agents for the treatment of various diseases. During 2000 to 2021, totally 54 carbohydrate-based drugs which contain carbohydrate moities as the major structural units have been approved as drugs or diagnostic agents. Here we provide a comprehensive review on the chemical structures, activities, and clinical trial results of these carbohydrate-based drugs, which are categorized by their indications into antiviral drugs, antibacterial/antiparasitic drugs, anticancer drugs, antidiabetics drugs, cardiovascular drugs, nervous system drugs, and other agents.

Decitabine Sensitizes the Radioresistant Lung Adenocarcinoma to Pemetrexed Through Upregulation of Folate Receptor Alpha

Chemotherapy is the backbone of subsequent treatment for patients with lung adenocarcinoma (LUAD) exhibiting radiation resistance, and pemetrexed plays a critical role in this chemotherapy. However, few studies have assessed changes in the sensitivity of LUAD cells to pemetrexed under radioresistant circumstances. Therefore, the objectives of this study were to delineate changes in the sensitivity of radioresistant LUAD cells to pemetrexed and to elucidate the related mechanisms and then develop an optimal strategy to improve the cytotoxicity of pemetrexed in radioresistant LUAD cells. Our study showed a much lower efficacy of pemetrexed in radioresistant cells than in parental cells, and the mechanism of action was the significant downregulation of folate receptor alpha (FRα) by long-term fractionated radiotherapy, which resulted in less cellular pemetrexed accumulation. Interestingly, decitabine effectively reversed the decrease in FRα expression in radioresistant cells through an indirect regulatory approach. Thereafter, we designed a combination therapy of pemetrexed and decitabine and showed that the activation of FRα by decitabine sensitizes radioresistant LUAD cells to pemetrexed both in vitro and in xenografts. Our findings raised a question regarding the administration of pemetrexed to patients with LUAD exhibiting acquired radioresistance and accordingly suggested that a combination of pemetrexed and decitabine would be a promising treatment strategy.

High expression level of serpin peptidase inhibitor clade E member 2 is associated with poor prognosis in lung adenocarcinoma

Background

Recent studies have revealed that serpin peptidase inhibitor clade E member 2 (SERPINE2) is associated with tumorigenesis. However, SERPINE2 expression and its role in lung adenocarcinomas are still unknown.

Methods

The expression levels of SERPINE2 in 74 consecutively resected lung adenocarcinomas were analyzed by using immunostaining. Inhibition of SERPINE2 expression by small interfering RNA (siRNA) was detected by quantitative PCR. Cell number assays and cell apoptosis assays were performed to clarify the cell-autonomous function of SERPINE2 in A549 and PC9 lung cancer cells.

Results

The overall survival of patients with high SERPINE2 expression was significantly worse than that of patients with low SERPINE2 expression (P = 0.0172). Multivariate analysis revealed that SERPINE2 expression was an independent factor associated with poor prognosis (P = 0.03237). The interference of SERPINE2 decreased cell number and increased apoptosis in A549 and PC9 cells

Conclusion

These results suggest that SERPINE2 can be used as a novel prognostic marker of lung adenocarcinoma.

Caspase Recruitment Domain-Containing Protein 9 Expression is a Novel Prognostic Factor for Lung Adenocarcinoma

Purpose

Caspase recruitment domain-containing protein 9 (CARD9) is expressed at high levels in bone marrow cells and has a crucial role in innate immunity. Current studies indicate that CARD9 also plays a key role in tumor progression, but there are few reports on the role of CARD9 in lung cancer. The aim of this study was to clarify the role of CARD9 in lung adenocarcinoma.

Patients and Methods

Lung adenocarcinoma tumor samples from 74 patients who underwent complete resection at Kobe University Hospital from January 2014 to December 2014 were analyzed by immunohistochemistry. The role of CARD9 in cancer cells was analyzed using lung cancer cell lines treated with CARD9 siRNA.

Results

High expression of CARD9 was observed in 32.4% of tumors, and compared to low expression of CARD9, high expression was associated with poorer overall survival (P = 0.0365). Univariate and multivariate analyses showed that high expression of CARD9 was an independent prognostic factor. Knockdown of CARD9 in lung adenocarcinoma cells inhibited proliferation but did not increase apoptosis. In addition, CARD9 activated the NF-κB pathway in a lung adenocarcinoma cell line.

Conclusion

CARD9 was shown to be an independent prognostic factor of poor outcome for lung cancer and may represent a molecular target for treatment.

Histone deacetylase inhibitor OBP‑801 and amrubicin synergistically inhibit the growth of squamous cell lung carcinoma by inducing mitochondrial ASK1‑dependent apoptosis

Squamous cell lung carcinoma (SQCLC) is an aggressive type of lung cancer. In contrast with the marked advances that have been achieved in the treatment of lung adenocarcinoma, there are currently no effective targeted therapies for SQCLC, for with cytotoxic drugs are still the main treatment strategy. Therefore, the present study aimed to develop novel combination therapies for SQCLC. The results demonstrated that a combined treatment with the potent histone deacetylase (HDAC) inhibitor OBP‑801 and the third‑generation anthracycline amrubicin synergistically inhibited the viability of SQCLC cell lines by inducing apoptosis signal‑regulating kinase 1 (ASK1)‑dependent, as well as JNK‑ and p38 mitogen‑activated protein kinase (MAPK)‑independent apoptosis. OBP‑801 treatment strongly induced the protein expression levels of thioredoxin‑interacting protein (TXNIP), and amrubicin treatment increased the levels of intracellular reactive oxygen species (ROS), which suggested that this combination oxidized and dissociated thioredoxin 2 (Trx2) from mitochondrial ASK1 and activated ASK1. Moreover, mouse xenograft experiments using human H520 SQCLC cells revealed that the co‑treatment potently suppressed tumor growth in vivo. These results suggested that a combined treatment with OBP‑801 and amrubicin may have potential as a therapeutic strategy for SQCLC.

Delivery of pemetrexed by magnetic nanoparticles: design, characterization, in vitro and in vivo assessment

Drug-loaded magnetic nanoparticles have been developed because of the advantages of specific drug targeting in cancer treatment. Pemetrexed (PEM) is a multi-targeting antifolate agent that is effective for the treatment of many cancers, for example, non-small cell lung cancer. Here, PEM loaded magnetic O-carboxymethyl chitosan (O-CMC) nanoparticles were prepared to deliver PEM on tumor tissue with an external magnetic field. The modification of chitosan to O-CMC was confirmed by FTIR analysis. Nanoparticle synthesis was performed via ionic gelation method. The diameter of magnetic O-CMC nanoparticles (MCMC) was found to be 130.1 ± 22.96 nm. After PEM loading, diameter was found to be 123.9 ± 11.42 nm. The drug release of PEM loaded MCMC (PMCMC) was slower in physiological medium than in acidic medium. A549-luc-C8 and CRL5807 cell lines were used for MTT test which showed that IC₅₀ values of nanoparticles were lower than PEM. The antitumor efficiency of PMCMC in xenograft tumor model was examined with in vivo imaging system (IVIS) and caliper and with hematological analyses. In vivo studies revealed that PMCMC had targeted antitumor activity in A549-luc-C8-tumor-bearing mice compared to PEM. As a result, it was suggested that PMCMC have great potential for the treatment of non-small cell lung cancer.

Anti-Angiogenic Effect of Orally Available Pemetrexed for Metronomic Chemotherapy

Metronomic chemotherapy (MCT) is defined as the frequent administration of low-dose chemotherapeutics, without long drug-free periods, with the exertion of antitumor activity exclusively through anti-angiogenic mechanisms. In this study, we have developed an orally available formulation of pemetrexed (PMX) for MCT. PMX was first complexed ionically with N^α-deoxycholyl-l-lysyl-methylester (DCK) as the permeation enhancer. This was followed by dispersion with poloxamer 188 and Labrasol to form the solid oral formulation of PMX (PMX/DCK-OP). PMX/DCK-OP exhibited a 10.6-fold increase in permeability across a Caco-2 cell monolayer compared to PMX alone. This resulted in a 70-fold increase in the oral bioavailability of PMX/DCK-OP in mice over oral PMX alone. In the A549 xenograft model, tumor volume was reduced by 51.1% in the PMX/DCK-OP treated group compared to only 32.8% in the maximum tolerated dose (MTD)-treated group. Furthermore, PMX/DCK-OP exhibited a significant anti-angiogenic effect on the A549 xenograft mice when compared to the MTD-treated group, as indicated by microvessel density quantification for CD-31. In addition, PMX/DCK-OP enhanced the release of an endogenous angiogenesis inhibitor, thrombospondin-1 (TSP-1), into both the blood circulation and the tumor microenvironment. Therefore, due to its oral route of administration, PMX/DCK-OP appears to be a better alternative to the conventional treatment of PMX.

Synergistic interaction of gemcitabine and paclitaxel by modulating acetylation and polymerization of tubulin in non-small cell lung cancer cell lines

Background: The combination of gemcitabine (GEM) and paclitaxel (PTX) was appealing for clinical exploration due to different mechanisms of action and partially non-overlapping toxicities.

Purpose: The aim of this study was to elucidate a potential effect of this combination on the proliferation of two non-small cell lung cancer (NSCLC) cell lines, A549 and H520.

Materials and methods: Cell lines were treated with GEM and PTX for 48 hours to evaluate the half maximal inhibitory concentration (IC50). To determine the combination index (CI), cell lines were exposed to GEM and PTX, in a constant ratio of IC50, by various combination treatments. GEM`s effect on tubulin was assessed by western blotting and immunofluorescent staining. GEM was combined with nanoparticle albumin-bound-paclitaxel (NP) in evaluating tumor growth inhibition.

Results: The IC50 of GEM and PTX in A549 and H520 were 6.6 nM and 46.1 nM, and 1.35 nM and 7.59 nM, respectively. Among the sequences explored (GEM→PTX, PTX→GEM, and GEM plus PTX simultaneously [GEM+PTX]), GEM→PTX produced a mean CI <1 in both cell lines. Western blotting and immunofluorescent staining revealed the intention expressions of acetylated tubulin protein and enhancement of tubulin polymerization within GEM→PTX group. A combination order GEM→NP also worked synergistically to suppress tumor growth.

Conclusion: The GEM→PTX sequence may represent a promising candidate regimen for the treatment of NSLCL.

Phospholipase Cε plays a crucial role in neutrophilic inflammation accompanying acute lung injury through augmentation of CXC chemokine production from alveolar epithelial cells

BACKGROUND

We have shown that phospholipase Cε (PLCε), an effector of Ras and Rap1 small GTPases, plays pivotal roles in inflammation and inflammation-associated carcinogenesis by augmenting proinflammatory cytokine production from epithelial cells of various organs. The purpose of this study is to analyze its role in neutrophilic alveolar inflammation accompanying acute lung injury (ALI), focusing on that in alveolar epithelial cells (AECs), which are known to make a major contribution to the pathogenesis of ALI.

METHODS

We examine the effect of the PLCε genotypes on the development of ALI induced by intratracheal administration of lipopolysaccharide (LPS) to PLCε wild-type (PLCε^+/+) and knockout (PLCε^ΔX/ΔX) mice. Pathogenesis of ALI is analyzed by histological examination of lung inflammation and measurements of the levels of various cytokines, in particular neutrophil-attracting chemokines such as Cxcl5, by quantitative reverse transcription-polymerase chain reaction and immunostaining. Primary cultures of AECs, established from PLCε^+/+ and PLCε^ΔX/ΔX mice, are used to analyze the roles of PLCε, protein kinase D (PKD) and nuclear factor-κB (NF-κB) in augmentation of LPS-induced Cxcl5 expression.

RESULTS

Compared to PLCε^+/+ mice, PLCε^ΔX/ΔX mice exhibit marked alleviation of lung inflammation as shown by great reduction in lung wet/dry weight ratios, accumulation of inflammatory cells in the alveolar space and thickening of alveolar walls as well as the number of neutrophils and the protein concentration in bronchoalveolar lavage fluid. Also, LPS-induced expression of the CXC family of chemokines, in particular Cxcl5, is substantially diminished in the total lung and AECs of PLCε^ΔX/ΔX mice. Moreover, LPS-induced Cxcl5 expression in primary cultured AECs is markedly suppressed on the PLCε^ΔX/ΔX background (p < 0.05 versus PLCε^+/+ AECs), which is accompanied by the reduction in phosphorylation of inhibitor κB (IκB), PKD and nuclear translocation of NF-κB p65. Also, it is suppressed by the treatment with inhibitors of PKD and IκB kinase, suggesting the involvement of the PLCε-PKD-IκB-NF-κB pathway.

CONCLUSIONS

PLCε-mediated augmentation of the production of the CXC family of chemokines, in particular Cxcl5, in AECs plays a crucial role in neutrophilic alveolar inflammation accompanying ALI, suggesting that PLCε may be a potential molecular target for the treatment of acute respiratory distress syndrome.

Role of S1P/S1PR3 axis in release of CCL20 from human bronchial epithelial cells

Background

Sphingosine kinase phosphorylates sphingosine to generate sphingosine 1 phosphate (S1P) following stimulation of the five plasma membrane G-protein-coupled receptors. The objective of this study is to clarify the role of S1P and its receptors (S1PRs), especially S1PR3 in airway epithelial cells.

Methods

The effects of S1P on asthma-related genes expression were examined with the human bronchial epithelial cells BEAS-2B and Calu-3 using a transcriptome analysis and siRNA of S1PRs. To clarify the role of CCL20 in the airway inflammation, BALB/c mice were immunized with ovalbumin (OVA) and subsequently challenged with an OVA-containing aerosol to induce asthma with or without intraperitoneal administration of anti-CCL20. Finally, the anti-inflammatory effect of VPC 23019, S1PR1/3 antagonist, in the OVA-induced asthma was examined.

Results

S1P induced the expression of some asthma-related genes, such as ADRB2, PTGER4, and CCL20, in the bronchial epithelial cells. The knock-down of SIPR3 suppressed the expression of S1P-inducing CCL20. Anti-CCL20 antibody significantly attenuated the eosinophil numbers in the bronchoalveolar lavage fluid (P<0.01). Upon OVA challenge, VPC23019 exhibited substantially attenuated eosinophilic inflammation.

Conclusions

S1P/S1PR3 pathways have a role in release of proinflammatory cytokines from bronchial epithelial cells. Our results suggest that S1P/S1PR3 may be a possible candidate for the treatment of bronchial asthma.

Searching Synergistic Dose Combinations for Anticancer Drugs

Recent development has enabled synergistic drugs in treating a wide range of cancers. Being highly context-dependent, however, identification of successful ones often requires screening of combinational dose on different testing platforms in order to gain the best anticancer effects. To facilitate the development of effective computational models, we reviewed the latest strategy in searching optimal dose combination from three perspectives: (1) mainly experimental-based approach; (2) Computational-guided experimental approach; and (3) mainly computational-based approach. In addition to the introduction of each strategy, critical discussion of their advantages and disadvantages were also included, with a strong focus on the current applications and future improvements.

Metformin synergistic pemetrexed suppresses non-small-cell lung cancer cell proliferation and invasion in vitro

The aim of this study was to investigate whether metformin in combination with pemetrexed has an effect on the treatment of non-small-cell lung cancer (NSCLC) models and to explore the related molecular mechanism. The half maximal inhibitory concentration (IC50) and combination index (CI) of metformin and pemetrexed were detected by the CCK8 assay to assess the antiproliferative and therapeutic effects of the two-drug combination. Flow cytometry (FCM) and invasion assays were used to estimate the variation in apoptosis rate and invasion ability of the differently treated NSCLC cell lines. Apoptotic markers were detected by western blotting to validate the data related to the antiproliferation and proapoptosis effects. Metformin monotherapy inhibited the growth of NSCLC cell lines and reduced the invasion ability to different degrees compared with the control groups (P < 0.05). Metformin in combination with pemetrexed produced a synergistic effect (CI < 0.90) compared with the two drugs in monotherapy in the three tested NSCLC cell lines. Metformin in combination with pemetrexed significantly increased the cell numbers of HCC827 cells at S phase (P < 0.001), and the combination therapy had no influence on the A549 and H1975 cell lines. We found that combining metformin with pemetrexed induced more cell apoptosis than metformin or pemetrexed used alone (P < 0.05), which was validated by the apoptotic markers. These results demonstrate that the combination of metformin and pemetrexed has a synergistic effect on the treatment of NSCLC cell lines by inducing apoptosis or blocking the cell cycle. Our data indicate that the combination of metformin and pemetrexed could have beneficial antitumor effects on NSCLC cells in vitro.

Glucose metabolism-targeted therapy and withaferin A are effective for epidermal growth factor receptor tyrosine kinase inhibitor-induced drug-tolerant persisters

In pathway‐targeted cancer drug therapies, the relatively rapid emergence of drug‐tolerant persisters (DTPs) substantially limits the overall therapeutic benefit. However, little is known about the roles of DTPs in drug resistance. In this study, we investigated the features of epidermal growth factor receptor–tyrosine kinase inhibitor‐induced DTPs and explored a new treatment strategy to overcome the emergence of these DTPs. We used two EGFR‐mutated lung adenocarcinoma cell lines, PC9 and II‐18. They were treated with 2 μM gefitinib for 6, 12, or 24 days or 6 months. We analyzed the mRNA expression of the stem cell‐related markers by quantitative RT‐PCR and the expression of the cellular senescence‐associated proteins. Then we sorted DTPs according to the expression pattern of CD133 and analyzed the features of sorted cells. Finally, we tried to ablate DTPs by glucose metabolism targeting therapies and a stem‐like cell targeting drug, withaferin A. Drug‐tolerant persisters were composed of at least two types of cells, one with the properties of cancer stem‐like cells (CSCs) and the other with the properties of therapy‐induced senescent (TIS) cells. The CD133^high cell population had CSC properties and the CD133^low cell population had TIS properties. The CD133^low cell population containing TIS cells showed a senescence‐associated secretory phenotype that supported the emergence of the CD133^high cell population containing CSCs. Glucose metabolism inhibitors effectively eliminated the CD133^low cell population. Withaferin A effectively eliminated the CD133^high cell population. The combination of phloretin and withaferin A effectively suppressed gefitinib‐resistant tumor growth.

Synergistic Antiproliferative Effects of a New Cucurbitacin B Derivative and Chemotherapy Drugs on Lung Cancer Cell Line A549

Nonsmall cell lung cancer (NSCLC) represents an important cause of mortality worldwide due to its aggressiveness and growing resistance to currently available therapy. Cucurbitacins have emerged as novel potential anticancer agents showing strong antiproliferative effects and can be promising candidates for combined treatments with clinically used anticancer agents. This study investigates the synergistic antiproliferative effects of a new semisynthetic derivative of cucurbitacin B (DACE) with three chemotherapy drugs: cisplatin (CIS), irinotecan (IRI), and paclitaxel (PAC) on A549 cells. The most effective combinations were selected for studies of the mechanism of action. Using an in silico tool, DACE seems to act by a different mechanism of action when compared with that of different classes of drugs already used in clinical settings. DACE also showed potent synergic effects with drugs, and the most potent combinations induced G2/M cell cycle arrest by modulating survivin and p53 expression, disruption of F-actin cytoskeleton, and cell death by apoptosis. These treatments completely inhibited the clonogenic potential and did not reduce the proliferation of nontumoral lung cells (MRC-5). DACE also showed relevant antimigratory and anti-invasive effects, and combined treatments modulated cell migration signaling pathways evolved with metastasis progression. The effects of DACE associated with drugs was potentiated by the oxidant agent l-buthionine-sulfoximine (BSO), and attenuated by N-acetilcysteine (NAC), an antioxidant agent. The antiproliferative effects induced by combined treatments were attenuated by a pan-caspase inhibitor, indicating that the effects of these treatments are dependent on caspase activity. Our data highlight the therapeutic potential of DACE used in combination with known chemotherapy drugs and offer important insights for the development of more effective and selective therapies against lung cancer.