Quinacrine Inhibits Cell Growth and Induces Apoptosis in Human Gastric Cancer Cell Line SGC-7901

Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage

BACKGROUND

With rapid increase in the global use of various plastics, microplastics (MPs) and nanoplastics (NPs) pollution and their adverse health effects have attracted global attention. MPs have been detected out in human body and both MPs and NPs showed female reproductive toxicological effects in animal models. Miscarriage (abnormal early embryo loss), accounting for 15-25% pregnant women worldwide, greatly harms human reproduction. However, the adverse effects of NPs on miscarriage have never been explored.

RESULTS

In this study, we identified that polystyrene (PS) plastics particles were present in women villous tissues. Their levels were higher in villous tissues of unexplained recurrent miscarriage (RM) patients vs. healthy control (HC) group. Furthermore, mouse assays further confirmed that exposure to polystyrene nanoplastics (PS-NPs, 50 nm in diameter, 50 or 100 mg/kg) indeed induced miscarriage. In mechanism, PS-NPs exposure (50, 100, 150, or 200 µg/mL) increased oxidative stress, decreased mitochondrial membrane potential, and increased apoptosis in human trophoblast cells by activating Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3 signaling through mitochondrial pathway. The alteration in this signaling was consistent in placental tissues of PS-NPs-exposed mouse model and in villous tissues of unexplained RM patients. Supplement with Bcl-2 could efficiently suppress apoptosis in PS-NPs-exposed trophoblast cells and reduce apoptosis and alleviate miscarriage in PS-NPs-exposed pregnant mouse model.

CONCLUSIONS

Exposure to PS-NPs activated Bcl-2/Cleaved-caspase-2/Cleaved-caspase-3, leading to excessive apoptosis in human trophoblast cells and in mice placental tissues, further inducing miscarriage.

Repurposing of Anti-Malarial Drug Quinacrine for Cancer Treatment: A Review

Quinacrine (QC), a synthetic drug belonging to the 9-aminoacridine family, has been used extensively to treat malaria and multiple ailments over the past several decades. Following its discovery in the 1920s and extensive use for the treatment of malaria for nearly two decades, numerous studies have explored its antineoplastic potential in both preclinical and clinical settings. Multiple studies spanning over seven decades have examined a wide range of QC anticancer activities across various types of cancers, along with the underlying mechanisms. Many of these mechanisms, including activation of the p53 signaling cascade and simultaneous NF-κB signaling inhibition, have been reported in various studies, bringing QC to a unique polypharmacological category drug possessing the potential to treat a wide variety of diseases, including cancer. This article summarizes most of the research conducted over several decades to uncover new molecular mechanisms activated or inactivated and directly correlate with antineoplastic activity QC.

Anti-Cancer Stem Cells Potentiality of an Anti-Malarial Agent Quinacrine: An Old Wine in a New Bottle

Quinacrine (QC) is a tricyclic compound and a derivative of 9-aminoacridine. It has been widely used to treat malaria and other parasitic diseases since the last century. Interestingly, studies have revealed that it also displays anti-cancer activities. Here, we have discussed the anti-cancer mechanism of QC along with its potentiality to specifically target cancer stem cells. The anti-cancer action of this drug includes DNA intercalation, inhibition of DNA repair mechanism, prevention of cellular growth, cell cycle arrest, inhibition of DNA and RNA polymerase activity, induction of autophagy, promotion of apoptosis, deregulation of cell signaling in cancer cells and cancer stem cells, inhibition of metastasis and angiogenesis. In addition, we have also emphasized on the synergistic effect of this drug with other potent chemotherapeutic agents and mentioned its different applications in anti-cancer therapy.

Undaria pinnatifida fucoidan nanoparticles loaded with quinacrine attenuate growth and metastasis of pancreatic cancer

Pancreatic cancer is a devastating gastrointestinal tumor with limited Chemotherapeutic options. Treatment is restricted by its poor vascularity and dense surrounding stroma. Quinacrine is a repositioned drug with an anticancer activity but suffers a limited ability to reach tumor cells. This could be enhanced using nanotechnology by the preparation of quinacrine-loaded Undaria pinnatifida fucoidan nanoparticles. The system exploited fucoidan as both a delivery system of natural origin and active targeting ligand. Lactoferrin was added as a second active targeting ligand. Single and dual-targeted particles prepared through nanoprecipitation and ionic interaction respectively were appraised. Both particles showed a size lower than 200 nm, entrapment efficiency of 80% and a pH-dependent release of the drug in the acidic environment of the tumor. The anticancer activity of quinacrine was enhanced by 5.7 folds in dual targeted particles compared to drug solution with a higher ability to inhibit migration and invasion of cancer. In vivo, these particles showed a 68% reduction in tumor volume compared to only 20% for drug solution. In addition, they showed a higher animals' survival rate with no hepatotoxicity. Hence, these particles could be an effective option for the eradication of pancreatic cancer cells.

Nano-synergistic combination of Erlotinib and Quinacrine for non-small cell lung cancer (NSCLC) therapeutics - Evaluation in biologically relevant in-vitro models

Non-small cell lung cancer (NSCLC), pre-dominant subtype of lung cancer, is a global disorder affecting millions worldwide. One of the early treatments for NSCLC was use of a first-generation tyrosine kinase inhibitor, Erlotinib (Erlo). However, chronic exposure to Erlo led to development of acquired drug resistance (ADR) in NSCLC, limiting the clinical use of Erlo. A potential approach to overcome development of ADR is a multi-drug therapy. It has been previously reported that Erlo and Quinacrine (QA), an anti-malarial drug, can work synergistically to inhibit tumor progression in NSCLC. However, the combination failed at clinical stages, citing lack of efficacy. In this study, an effort has been made to improve the efficacy of Erlo-QA combination via development of nanoformulations, known to enhance therapeutic efficacy of potent chemotherapies. Synergy between Erlo and QA was measured via estimating the combination indices (CI). It was seen that established combination of nanoformulations (CI: 0.25) had better synergy than plain drug solutions (CI: 0.85) in combination. Following extensive in-vitro testing, data were simulated in biologically relevant 3D tumor models. Two tumor models were developed for extensive in-vitro testing, 3D-Spheroids grown in ultra-low attachment culture plates for efficacy evaluation and a 5D-spheroid model in 5D-sphericalplate with capability of growing 750 spheroids/well for protein expression analysis. Extensive studies on these models revealed that combination of Erlo and QA nanoformulations overall had a better effect in terms of synergy enhancement as compared to plain drug combination. Further, effect of combinatorial therapy on molecular markers was evaluated on 5D-Sphericalplate leading to similar effects on synergy enhancement. Results from present study suggests that combination of nanoformulations can improve the synergy between Erlo and QA while reducing the overall therapeutic dose.

Drug Repositioning in Oncology

BACKGROUND

The worldwide increase in the occurrence of cancer associated with the limitations of immunotherapy and the emergence of resistance have impaired the prognosis of cancer patients, which leads to the search for alternative treatment methods. Drug repositioning, a well-established process approved by regulatory agencies, is considered an alternative strategy for the fast identification of drugs, because it is relatively less costly and represents lower risks for patients.

AREAS OF UNCERTAINTY

We report the most relevant studies about drug repositioning in oncology, emphasizing that its implementation faces financial and regulatory obstacles, making the creation of incentives necessary to stimulate the involvement of the pharmaceutical industry.

DATA SOURCES

We present 63 studies in which 52 non-anticancer drugs with anticancer activity against a number of malignancies are described.

THERAPEUTIC INNOVATIONS

Some have already been the target of phase III studies, such as the Add-Aspirin trial for nonmetastatic solid tumors, as well as 9 other drugs (aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, ritonavir, and sertraline) in the CUSP9* clinical trial for the treatment of recurrent glioblastoma. Others have already been successful in repositioning such as thalidomide, zoledronic acid, celecoxib, methotrexate, and gemcitabine.

CONCLUSIONS

Therefore, drug repositioning represents a promising alternative for the treatment of oncological disorders; however, the support from funding agencies and from the government is still needed, the latter regarding regulatory issues.

Targeting tumor hypoxia and mitochondrial metabolism with anti-parasitic drugs to improve radiation response in high-grade gliomas

High-grade gliomas (HGGs), including glioblastoma and diffuse intrinsic pontine glioma, are amongst the most fatal brain tumors. These tumors are associated with a dismal prognosis with a median survival of less than 15 months. Radiotherapy has been the mainstay of treatment of HGGs for decades; however, pronounced radioresistance is the major obstacle towards the successful radiotherapy treatment. Herein, tumor hypoxia is identified as a significant contributor to the radioresistance of HGGs as oxygenation is critical for the effectiveness of radiotherapy. Hypoxia plays a fundamental role in the aggressive and resistant phenotype of all solid tumors, including HGGs, by upregulating hypoxia-inducible factors (HIFs) which stimulate vital enzymes responsible for cancer survival under hypoxic stress. Since current attempts to target tumor hypoxia focus on reducing oxygen demand of tumor cells by decreasing oxygen consumption rate (OCR), an attractive strategy to achieve this is by inhibiting mitochondrial oxidative phosphorylation, as it could decrease OCR, and increase oxygenation, and could therefore improve the radiation response in HGGs. This approach would also help in eradicating the radioresistant glioma stem cells (GSCs) as these predominantly rely on mitochondrial metabolism for survival. Here, we highlight the potential for repurposing anti-parasitic drugs to abolish tumor hypoxia and induce apoptosis of GSCs. Current literature provides compelling evidence that these drugs (atovaquone, ivermectin, proguanil, mefloquine, and quinacrine) could be effective against cancers by mechanisms including inhibition of mitochondrial metabolism and tumor hypoxia and inducing DNA damage. Therefore, combining these drugs with radiotherapy could potentially enhance the radiosensitivity of HGGs. The reported efficacy of these agents against glioblastomas and their ability to penetrate the blood-brain barrier provides further support towards promising results and clinical translation of these agents for HGGs treatment.

Understanding Breast cancer: from conventional therapies to repurposed drugs

Breast cancer is the most common cancer among women and is considered a developed country disease. Moreover, is a heterogenous disease, existing different types and stages of breast cancer development, therefore, better understanding of cancer biology, helps to improve the development of therapies. The conventional treatments accessible after diagnosis, have the main goal of controlling the disease, by improving survival. In more advance stages the aim is to prolong life and symptom palliation care. Surgery, radiation therapy and chemotherapy are the main options available, which must be adapted to each person individually. However, patients are developing resistance to the conventional therapies. This resistance is due to alterations in important regulatory pathways such as PI3K/AKt/mTOR, this pathway contributes to trastuzumab resistance, a reference drug to treat breast cancer. Therefore, is proposed the repurposing of drugs, instead of developing drugs de novo, for example, to seek new medical treatments within the drugs available, to be used in breast cancer treatment. Providing safe and tolerable treatments to patients, and new insights to efficacy and efficiency of breast cancer treatments. The economic and social burden of cancer is enormous so it must be taken measures to relieve this burden and to ensure continued access to therapies to all patients. In this review we focus on how conventional therapies against breast cancer are leading to resistance, by reviewing those mechanisms and discussing the efficacy of repurposed drugs to fight breast cancer.

Quinacrine inhibits GSTA1 activity and induces apoptosis through G1/S arrest and generation of ROS in human non-small cell lung cancer cell lines

Background: Quinacrine (QC) is popular for its anti-malarial activity. It has been reported exhibiting anti-cancerous properties by suppressing nuclear factor-κB and activating p53 signaling; however, its effect on cellular pathways in human non-small cell lung cancer (NSCLC) has not been studied.

Materials and Methods: Binding of QC with GSTA1 was studied computationally as well as through GST activity assay kit. Cell viability, cell cycle and mitochondrial membrane potential activity were studied using flow cytometry. RT-PCR and western blot were carried out to understand the involvement of various genes at their mRNA as well as protein level.

Results: QC inhibited the activity of GSTA1 approximately by 40–45% which inhibits cell survival and promotes apoptosis. QC reduced viability of NSCLC cells in a dose-dependent manner. It also causes nuclear fragmentation, G₁/S arrest of cell cycle and ROS generation; which along with disruption of mitochondrial membrane potential activity leads to apoptotic fate.

Conclusions: Results revealed, QC has promising anti-cancer potential against NSCLC cells via inhibition of GSTA1, induction of G₁/S arrest and ROS mediated apoptotic signaling.

Lactoferrin/Hyaluronic acid double-coated lignosulfonate nanoparticles of quinacrine as a controlled release biodegradable nanomedicine targeting pancreatic cancer

Quinacrine is an antimalarial drug that was repositioned for treatment of cancer. This is the first work to enhance quinacrine activity and minimize its associated hepatotoxicity via loading into bio-degradable, bio-renewable lignosulfonate nanoparticles. Particles were appraised for treatment of pancreatic cancer, one of the most life-threatening tumors with a five-year survival estimate. Optimum nanocomposites prepared by polyelectrolyte interaction exhibited a particle size of 138 nm, a negative surface charge (-28 mV) and a pH dependent release of the drug in an acidic environment. Ligands used for active targeting (lactoferrin and hyaluronic acid) were added to nanoparticles' surface via layer by layer coating technique. The highest anticancer activity on PANC-1 cells was demonstrated with dual active targeted particles (3-fold decrease in IC₅₀) along with an increased ability to inhibit migration and invasion of pancreatic cancer cells. In vivo studies revealed that elaborated nanoparticles particles showed the highest tumor volume reduction with enhanced survival without any toxicity on major organs. In conclusion, the elaborated nanoparticles could be considered as a promising targeted nanotherapy for treatment of pancreatic cancer with higher efficacy& survival rate and lower organ toxicity.

Development of inhalable quinacrine loaded bovine serum albumin modified cationic nanoparticles: Repurposing quinacrine for lung cancer therapeutics

Drug repurposing is on the rise as an atypical strategy for discovery of new molecules, involving use of pre-existing molecules for a different therapeutic application than the approved indication. Using this strategy, the current study aims to leverage effects of quinacrine (QA), a well-known anti-malarial drug, for treatment of non-small cell lung cancer (NSCLC). For respiratory diseases, designing a QA loaded inhalable delivery system has multiple advantages over invasive delivery. QA-loaded nanoparticles (NPs) were thus prepared using polyethyleneimine (PEI) as a cationic stabilizer. While the use of PEI provided cationic charge on the particles, it also mediated a burst release of QA and demonstrated potential particle toxicity. These concerns were circumvented by coating nanoparticles with bovine serum albumin (BSA), which retained the cationic charge, reduced NP toxicity and modulated QA release. Prepared nanoparticles were characterized for physicochemical properties along with their aerosolization potential. Therapeutic efficacy of the formulations was tested in different NSCLC cells. Mechanism of higher anti-proliferation was evaluated by studying cell cycle profile, apoptosis and molecular markers involved in the progression of lung cancer. BSA coated QA nanoparticles demonstrated good aerosolization potential with a mass median aerodynamic diameter of significantly less than 5 µm. Nanoparticles also demonstrated improved therapeutic efficacy against NSCLC cells in terms of low IC₅₀ values, cell cycle arrest at G2/M phase and autophagy inhibition leading to increased apoptosis. BSA coated QA NPs also demonstrated enhanced therapeutic efficacy in a 3D cell culture model. The present study thus lays solid groundwork for pre-clinical and eventual clinical studies as a standalone therapy and in combination with existing chemotherapeutics.

Identification of p53 Activators in a Human Microarray Compendium

Biomarkers predictive of molecular and toxicological effects are needed to interpret emerging high-throughput transcriptomic data streams. The previously characterized 63 gene TGx-DDI biomarker that includes 20 genes known to be regulated by p53 was previously shown to accurately predict DNA damage in chemically treated cells. We comprehensively evaluated whether the molecular basis of the DDI predictions was based on a p53-dependent response. The biomarker was compared to microarray data in a compendium derived from human cells using the Running Fisher test, a nonparametric correlation test. Using the biomarker, we identified conditions that led to p53 activation, including exposure to the chemical nutlin-3 which disrupts interactions between p53 and the negative regulator MDM2 or by knockdown of MDM2. The expression of most of the genes in the biomarker (75%) were found to depend on p53 activation status based on gene behavior after TP53 overexpression or knockdown. The biomarker identified DDI chemicals that were strong inducers of p53 in wild-type cells; these p53 responses were decreased or abolished in cells after p53 knockdown by siRNAs. Using the biomarker, we screened ∼1950 chemicals in ∼9800 human cell line chemical vs control comparisons and identified ∼100 chemicals that caused p53 activation. Among the positive chemicals were many that are known to activate p53 through direct and indirect DNA damaging mechanisms. These results contribute to the evidence that the TGx-DDI biomarker is useful for identifying chemicals that cause DDI and activate p53.

Quinacrine Depletes BCR-ABL and Suppresses Ph-Positive Leukemia Cells

Drug resistance to TKIs and the existance of CML leukemia stem cells is an urgent problem. In this study, we demonstrate that quinacrine (QC) induces apoptosis in BCR-ABL positive CML and acute lymphoblastic leukemia (ALL) cells. Interestingly, QC inhibits the colony formation of primary CD34⁺ progenitor/stem leukemia cells from CML patients. QC targets RNA polymerase I, which produces ribosomal (r)RNA, involving in protein translation process. Also, QC treatment prolongs CML-like mice survival and inhibits K562 tumor growth in vivo. In conclusion, we demonstrate that QC depletes BCR-ABL protein and suppresses Ph-positive leukemia cells in vitro and in vivo.

The design of 1,4-naphthoquinone derivatives and mechanisms underlying apoptosis induction through ROS-dependent MAPK/Akt/STAT3 pathways in human lung cancer cells

The natural compound 1,4-naphthoquinone has potent anti-tumor activity. However, the clinical application of 1,4-naphthoquinone and its derivatives has been limited by their side effects. In this study, we attempted to reduce the toxicity of 1,4-naphthoquinone by synthesizing two derivatives: 2,3-dihydro-2,3-epoxy-2-propylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (EPDMNQ) and 2,3-dihydro-2,3-epoxy-2-nonylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (ENDMNQ). Then we evaluated the cytotoxicity and molecular mechanisms of these compounds in lung cancer cells. EPDMNQ and ENDMNQ significantly inhibited the viabilities of three lung cancer cell lines and induced A549 cell cycle arrest at the G1 phase. In addition, they induced the apoptosis of A549 lung cancer cells by increasing the phosphorylation of p38 and c-Jun N-terminal kinase (p-JNK), and decreasing the phosphorylation of extracellular signal-related kinase (p-ERK), protein kinase B (Akt), and signal transducer and activator of transcription 3 (STAT3). Furthermore, they increased reactive oxygen species (ROS) levels in A549 cells; however, pretreatment with the ROS inhibitor N-acetyl-l-cysteine significantly inhibited EPDMNQ- and ENDMNQ-mediated apoptosis and reversed apoptotic proteins expression. In conclusion, EPDMNQ and ENDMNQ induced G1 phase cell cycle arrest and apoptosis in A549 cells via the ROS-mediated activation of mitogen activated protein kinase (MAPK), Akt and STAT3 signaling pathways.

Novel applications for an established antimalarial drug: tumoricidal activity of quinacrine

Quinacrine (QC), a synthetic antimalarial drug, was consistently used worldwide to combat malaria during the last century. Interestingly, later studies revealed that it also displays various additional properties, specifically antitumor activity. QC's antitumor activity occurs via a variety of pathways, including DNA intercalation, angiogenesis inhibition, signal transduction regulation, cell cycle arrest and autophagy induction. In combination with traditional therapies such as chemotherapy and radiotherapy, QC has also displayed synergistic effects against tumors, which may open promising therapeutic avenues. However, the breadth and complexity of its antitumor mechanisms have not yet been fully elucidated. In this review, we have systematically categorized QC's reported antitumor mechanisms from recent studies, to enable a deeper understanding of its antitumor activity.

Quinacrine pretreatment reduces microwave-induced neuronal damage by stabilizing the cell membrane

Quinacrine, widely used to treat parasitic diseases, binds to cell membranes. We previously found that quinacrine pretreatment reduced microwave radiation damage in rat hippocampal neurons, but the molecular mechanism remains poorly understood. Considering the thermal effects of microwave radiation and the protective effects of quinacrine on heat damage in cells, we hypothesized that quinacrine would prevent microwave radiation damage to cells in a mechanism associated with cell membrane stability. To test this, we used retinoic acid to induce PC12 cells to differentiate into neuron-like cells. We then pretreated the neurons with quinacrine (20 and 40 mM) and irradiated them with 50 mW/cm² microwaves for 3 or 6 hours. Flow cytometry, atomic force microscopy and western blot assays revealed that irradiated cells pretreated with quinacrine showed markedly less apoptosis, necrosis, and membrane damage, and greater expression of heat shock protein 70, than cells exposed to microwave irradiation alone. These results suggest that quinacrine stabilizes the neuronal membrane structure by upregulating the expression of heat shock protein 70, thus reducing neuronal injury caused by microwave radiation.

Quinacrine upregulates p21/p27 independent of p53 through autophagy-mediated downregulation of p62-Skp2 axis in ovarian cancer

We have previously shown that the anti-malarial compound Quinacrine (QC) inhibits ovarian cancer (OC) growth by modulating autophagy. In the present study we extended these studies to identify the molecular pathways regulated by QC to promote apoptosis independent of p53 status in OC. QC exhibited strong anti-cancer properties in OC cell lines in contrast to other anti-malarial autophagy inhibiting drugs. QC treatment selectively upregulated cell cycle inhibitor p21, and downregulated F box protein Skp2 and p62/SQSTM1 expression independent of p53 status. Genetic downregulation of key autophagy protein ATG5 abolished QC-mediated effects on both cell cycle protein p21/Skp2 as well as autophagic cargo protein p62. Furthermore, genetic silencing of p62/SQSTM1 resulted in increased sensitivity to QC-mediated apoptosis, downregulated Skp2 mRNA and increased accumulation of p21 expression. Likewise, genetic knockdown of Skp2 resulted in the upregulation of p21 and p27 and increased sensitivity of OC cells to QC treatment. In contrast, transient overexpression of exogenous p62-HA plasmid rescued the QC-mediated Skp2 downregulation indicating the positive regulation of Skp2 by p62. Collectively, these data indicate that QC-mediated effects on cell cycle proteins p21/Skp2is autophagy-dependent and p53-independent in high grade serious OC cells.

Anticancer effect of quinacrine on diffuse large B‑cell lymphoma via inhibition of MSI2‑NUMB signaling pathway

Diffuse large B‑cell lymphoma (DLBCL) is the most common subtype of non‑Hodgkin's lymphoma. Despite improvements in the clinical outcomes of DLBCL, ~30% of patients will develop relapse/refractory disease. Therefore, novel therapeutic drugs have been investigated to improve disease outcomes. Previous studies have revealed the anticancer effects of quinacrine (QC) on tumor cells in vitro, although its role in human DLBCL is yet to be identified. The present study sought to examine the cytotoxic effect of QC on DLBCL cells. QC induced G0/G1 cell cycle arrest and apoptosis in the DLBCL cell lines SU‑DHL‑8 and OCI‑LY01, in a dose‑dependent manner, in addition to the downregulation of cyclin‑dependent kinase 4/6 and the upregulation of cleaved poly‑ADP ribose polymerase 1. Upon exposure to QC, RNA‑binding protein Musashi homolog 2 inactivation and activation of protein numb homolog were observed. In addition, QC was able to inhibit the expression of Myc proto‑oncogene protein. The results of the present study indicated that QC may be a potential anti‑DLBCL drug.

Cryptotanshinone induces ROS-mediated apoptosis in human gastric cancer cells

Cryptotanshinone (CT), isolated from the plant Salvia miltiorrhiza Bunge, has been reported to have potential anticancer effects on human prostate and breast cancer cells. However, the mechanisms of action of CT on gastric cancer (GC) cells are not well understood. Here we investigated the antitumor effects of CT on GC cells and its possible molecular mechanism. We found CT suppressed viability of twelve GC cell lines in a dose-dependent manner. CT induced cell cycle arrest at the G2/M phase and mitochondrial apoptosis accompanying the accumulation of reactive oxygen species (ROS). Pretreatment with ROS inhibitor N-acetyl-L-cysteine (NAC) blocked CT-induced apoptosis. CT increased p-JNK and p-p38, and decreased p-ERK and p-STAT3 protein expression, these effects were prevented by NAC. Furthermore, a xenograft assay showed that CT significantly inhibited MKN-45 cell-induced tumor growth in vivo by increasing expression of pro-apoptotic proteins (p-JNK, p-38 and cleaved-caspase-3) and reducing expression of anti-apoptotic proteins (p-ERK and p-STAT3) without adverse effects on nude mice weight. In conclusion, CT induced apoptosis and cell cycle arrest in GC cells via ROS-mediated MAPK and AKT signaling pathways, and this CT may be a useful compound for the developing anticancer agents for GC.

Quinacrine induces the apoptosis of human leukemia U937 cells through FOXP3/miR-183/β-TrCP/SP1 axis-mediated BAX upregulation

Quinacrine, which is clinically used as an antimalarial drug, has anti-cancer activity. However, mechanism underlying its cytotoxic effect remains to be completely elucidated. In the present study, we investigated the cytotoxic effect of quinacrine on human leukemia U937 cells. Quinacrine-induced apoptosis of U937 cells was accompanied with ROS generation, mitochondrial depolarization, and BAX upregulation. Quinacrine-treated U937 cells showed ROS-mediated p38 MAPK activation and ERK inactivation, which in turn upregulated FOXP3 transcription. FOXP3-mediated miR-183 expression decreased β-TrCP mRNA stability and suppressed β-TrCP-mediated SP1 degradation, thus increasing SP1 expression in U937 cells. Upregulated SP1 expression further increased BAX expression. BAX knock-down attenuated quinacrine-induced mitochondrial depolarization and increased the viability of quinacrine-treated cells. Together, our data indicate that quinacrine-induced apoptosis of U937 cells is mediated by mitochondrial alterations triggered by FOXP3/miR-183/β-TrCP/SP1 axis-mediated BAX upregulation.

A Quinacrine Analogue Selective Against Gastric Cancer Cells: Insight from Biochemical and Biophysical Studies

One of the earliest synthetic antimalarial drugs, quinacrine, was recently reported as interesting for the treatment of acute myeloid leukemia. Inspired by this and similar findings, we evaluated a set of quinacrine analogues against gastric (MKN-28), colon (Caco-2), and breast (MFC-7) cancer cell lines and one normal human fibroblast cell line (HFF-1). All the compounds, previously developed by us as dual-stage antimalarial leads, displayed antiproliferative activity, and one of the set stood out as selective toward the gastric cancer cell line, MKN-28. Interestingly, this compound was transported across an in vitro MKN-28 model cell line in low amounts, and approximately 80 % was trapped inside those cells. Nuclear targeting of the same compound and its interactions with calf thymus DNA were assessed through combined fluorescence microscopy, spectroscopy, and calorimetry studies, which provided evidence for the compound's ability to reach the nucleus and to interact with DNA.

Multifunctional targeting daunorubicin plus quinacrine liposomes, modified by wheat germ agglutinin and tamoxifen, for treating brain glioma and glioma stem cells

Most anticancer drugs are not able to cross the blood-brain barrier (BBB) effectively while surgery and radiation therapy cannot eradicate brain glioma cells and glioma stem cells (GSCs), hence resulting in poor prognosis with high recurrence rates. In the present study, a kind of multifunctional targeting daunorubicin plus quinacrine liposomes was developed for treating brain glioma and GSCs. Evaluations were performed on in-vitro BBB model, murine glioma cells, GSCs, and GSCs bearing mice. Results showed that the multifunctional targeting daunorubicin plus quinacrine liposomes exhibited evident capabilities in crossing the BBB, in killing glioma cells and GSCs and in diminishing brain glioma in mice. Action mechanism studies indicated that the enhanced efficacy of the multifunctional targeting drugs-loaded liposomes could be due to the following aspects: evading the rapid elimination from blood circulation; crossing the BBB effectively; improving drug uptake by glioma cells and GSCs; down-regulating the overexpressed ABC transporters; inducing apoptosis of GSCs via up-regulating apoptotic receptor/ligand (Fas/Fasl), activating apoptotic enzymes (caspases 8, 9 and 3), activating pro-apoptotic proteins (Bax and Bok), activating tumor suppressor protein (P53) and suppressing anti-apoptotic proteins (Bcl-2 and Mcl-1). In conclusion, the multifunctional targeting daunorubicin plus quinacrine liposomes could be used as a potential therapy for treating brain glioma and GSCs.

Extending in silico mechanism-of-action analysis by annotating targets with pathways: application to cellular cytotoxicity readouts

Background: An in silico mechanism-of-action analysis protocol was developed, comprising molecule bioactivity profiling, annotation of predicted targets with pathways and calculation of enrichment factors to highlight targets and pathways more likely to be implicated in the studied phenotype. Results: The method was applied to a cytotoxicity phenotypic endpoint, with enriched targets/pathways found to be statistically significant when compared with 100 random datasets. Application on a smaller apoptotic set (10 molecules) did not allowed to obtain statistically relevant results, suggesting that the protocol requires modification such as analysis of the most frequently predicted targets/annotated pathways. Conclusion: Pathway annotations improved the mechanism-of-action information gained by target prediction alone, allowing a better interpretation of the predictions and providing better mapping of targets onto pathways.

Anticancer effects of 4-vinyl-2,6-dimethoxyphenol (canolol) against SGC-7901 human gastric carcinoma cells

Gastric cancer remains the fourth most commonly diagnosed cancer and is the second leading cause of cancer-related mortality worldwide. The aim of this study was to investigate the effects of canolol on the proliferation and apoptosis of SGC-7901 human gastric cancer cells and its relevant molecular mechanisms. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to observe the effect of canolol on the proliferation of SGC-7901 human gastric adenocarcinoma cells. The results showed that SGC-7901 cells exhibited a marked dose-dependent reduction in the proliferation rate. The survival rate of the cells was 88.86±1.58% at 50 μmol/l, decreasing to 53.73±1.51% at 800 μmol/l (P<0.05). By contrast, canolol had no significant toxicity on the human gastric mucosal epithelial cell line GES-1. The vivid images of cell morphology using an inverted microscope provided confirmation of the MTT assay. Treatment of SGC-7901 cells with canolol resulted in apoptosis demonstrated by flow cytometry. Furthermore, canolol downregulated the mRNA levels of COX-2, but had no significant effect on the mRNA expession of the Bax and Bcl-2 genes. These findings suggest that canolol has potential to be developed as a new natural anti-gastric carcinoma agent.