Lawsone derivatives target the Wnt/β-catenin signaling pathway in multidrug-resistant acute lymphoblastic leukemia cells

Lawsone Unleashed: A Comprehensive Review on Chemistry, Biosynthesis, and Therapeutic Potentials

Lawsone, a naturally occurring organic compound also called hennotannic acid, obtained mainly from Lawsonia inermis (Henna). It is a potential drug-like molecule with unique chemical and biological characteristics. Traditionally, henna is used in hair and skin coloring and is also a medicinal herb for various diseases. It is also widely used as a starting material for the synthesis of various drug molecules. In this review, we investigate on the chemistry, biosynthesis, physical and biological properties of lawsone. The results showed that lawsone has potential antioxidant, anti-inflammatory, antimicrobial and antitumor properties. It also induces cell cycle inhibition and programmed cell death in cancer, making it a potential chemotherapeutic agent. Additionally, inhibition of pro-inflammatory cytokine production makes it an essential treatment for inflammatory diseases. Exploration of its biosynthetic pathway can pave the way for its development into targets for new drug development. In future, well-thought-out clinical studies should be made to verify its safety and efficacy.

Natural medicinal compounds target signal transduction pathways to overcome ABC drug efflux transporter-mediated multidrug resistance in cancer

ATP-binding cassette (ABC) transporters such as ABCB1, ABCG2, and ABCC1 are the major players in drug efflux-mediated multidrug resistance (MDR), which severely affects the efficacy of chemotherapy. Several synthetic compounds block the drug transport by ABC transporters; however, they exhibit a narrow therapeutic window, and produce side effects in non-target normal tissues. Conversely, the downregulation of the expression of ABC drug transporters seems to be a promising strategy to reverse MDR in cancer cells. Several signaling pathways, such as NF-κB, STAT3, Gli, NICD, YAP/TAZ, and Nrf2 upregulate the expression of ABC drug transporters in drug-resistant cancers. Recently, natural medicinal compounds have gained importance to overcome the ABC drug-efflux pump-mediated MDR in cancer. These compounds target transcription factors and the associated signal transduction pathways, thereby downregulating the expression of ABC transporters in drug-resistant cancer cells. Several potent natural compounds have been identified as lead candidates to synergistically enhance chemotherapeutic efficacy, and a few of them are already in clinical trials. Therefore, modulation of signal transduction pathways using natural medicinal compounds for the reversal of ABC drug transporter-mediated MDR in cancer is a novel approach for improving the efficiency of the existing chemotherapeutics. In this review, we discuss the modulatory role of natural medicinal compounds on cellular signaling pathways that regulate the expression of ABC transporters in drug-resistant cancer cells.

Inhibitory effect of O-propargyllawsone in A549 lung adenocarcinoma cells

BACKGROUND

Lung cancer is the deadliest type of cancer in the world and the search for compounds that can treat this disease is highly important. Lawsone (2-hydroxy-1,4-naphtoquinone) is a naphthoquinone found in plants from the Lawsone genus that show a high cytotoxic effect in cancer cell lines and its derivatives show an even higher cytotoxic effect.

METHODS

Sulforhodamine B was used to evaluate the cytotoxic activity of compounds on tumor cells. Clonogenic assay was used to analyze the reduction of colonies and wound healing assay to the migratory capacity of A549 cells. Apoptosis and necrosis were analyzed by flow cytometer and Giemsa staining. Hemolysis assay to determine toxicity in human erythrocytes.

RESULTS

Lawsone derivatives were evaluated and compound 1 (O-propargyllawsone) was the one with the highest cytotoxic effect, with IC50 below 2.5 µM in A549 cells. The compound was able to reduce colony formation and inhibit cell migration. Morphological changes and cytometry analysis show that the compound induces apoptosis and necrosis in A549 cells.

CONCLUSIONS

These results show that O-propargyllawsone show a cytotoxic effect and may induce apoptosis in A549 cells.

Novel pyrrolidine-aminophenyl-1,4-naphthoquinones: structure-related mechanisms of leukemia cell death

Novel derivatives of aminophenyl-1,4-naphthoquinones, in which a pyrrolidine group was added to the naphthoquinone ring, were synthesized and investigated for the mechanisms of leukemic cell killing. The novel compounds, TW-85 and TW-96, differ in the functional (methyl or hydroxyl) group at the para-position of the aminophenyl moiety. TW-85 and TW-96 were found to induce concentration- and time-dependent apoptotic and/or necrotic cell death in human U937 promonocytic leukemia cells but only TW-96 could also kill K562 chronic myeloid leukemia cells and CCRF-CEM lymphoblastic leukemia cells. Normal peripheral blood mononuclear cells were noticeably less responsive to both compounds than leukemia cells. At low micromolar concentrations used, TW-85 killed U937 cells mainly by inducing apoptosis. TW-96 was a weaker apoptotic agent in U937 cells but proved to be cytotoxic and a stronger inducer of necrosis in all three leukemic cell lines tested. Both compounds induced mitochondrial permeability transition pore opening, cytochrome c release, and caspase activation in U937 cells. Cytotoxicity induced by TW-96, but not by TW-85, was associated with the elevation of the cytosolic levels of reactive oxygen species (ROS). The latter was attenuated by diphenyleneiodonium, indicating that NADPH oxidase was likely to be the source of ROS generation. Activation of p38 MAPK by the two agents appeared to prevent necrosis but differentially affected apoptotic cell death in U937 cells. These results further expand our understanding of the structure-activity relationship of aminophenyl-1,4-naphthoquinones as potential anti-leukemic agents with distinct modes of action.

Comprehensive Genomic Analysis for Identifying FZD6 as a Novel Diagnostic Biomarker for Acute Myeloid Leukemia

As a family of G protein-coupled receptors (GPCRs) with a seven-span transmembrane structure, frizzled class receptors (FZDs) play crucial roles in regulating multiple biological functions. However, their transcriptional expression profile and prognostic significance in acute myeloid leukemia (AML) are unclear. In AML, the role of FZDs was explored by performing the comprehensive analysis on the relationship between clinical characteristics and mRNA expression profiles from public databases including cBioPortal for Cancer Genomics, Gene Expression Profile Interactive Analysis (GEPIA), and Cancer Cell Line Encyclopedia (CCLE). We identified that in the majority of 27 AML cell lines, frizzled class receptor 6 (FZD6) was high-expressed. A significantly higher expression of FZD6 in AML patients was observed when compared to normal controls (P < 0.01). Compared with intermediate and poor/adverse risk group patients, FZD6 expressed much lower in cytogenetic favorable risk group patients (P < 0.0001). Patients with higher-expressed FZD6 were associated with shorter overall survival (OS) (P = 0.0089) rather than progression-free survival (PFS). However, the predictive effect of FZD6 on OS could be reversed by hematopoietic stem cell transplantation (HSCT). The data of gene set enrichment analysis (GSEA) demonstrated that 4 gene sets, including MYC targets, HEME metabolism, E2F targets, and UV response, were differentially enriched in the high-expression FZD6 group. To conclude, the study suggested that high expression of FZD6 might be a novel poor prognostic biomarker for AML treatment.

The Wnt/β-catenin signalling pathway in Haematological Neoplasms

Leukaemia and lymphoma are common malignancies. The Wnt pathway is a complex network of proteins regulating cell proliferation and differentiation, as well as cancer development, and is divided into the Wnt/β-catenin signalling pathway (the canonical Wnt signalling pathway) and the noncanonical Wnt signalling pathway. The Wnt/β-catenin signalling pathway is highly conserved evolutionarily, and activation or inhibition of either of the pathways may lead to cancer development and progression. The aim of this review is to analyse the mechanisms of action of related molecules in the Wnt/β-catenin pathway in haematologic malignancies and their feasibility as therapeutic targets.

Knockdown of LncRNA CRNDE suppresses proliferation and P-glycoprotein-mediated multidrug resistance in acute myelocytic leukemia through the Wnt/β-catenin pathway

Mechanisms involved in non-coding RNAs have been implicated in multidrug resistance (MDR) of acute myeloid leukemia (AML). Long non-coding RNA (lncRNAs) colorectal neoplasia differentially expressed (CRNDE) is reported to be involved in the malignant progression in AML. The purpose of the present study is to explore the roles and potential molecular mechanism of CRNDE in the MDR in AML. In our study, we confirmed that the expression of CRNDE was significantly up-regulated in patients with AML, especially in AML patients after adriamycin (ADR)-based chemotherapy. Spearman correlation analysis showed a positive correlation between the levels of CRNDE and MDR1 in AML patients after ADR-based chemotherapy. Moreover, CRNDE was up-regulated in AML cells, especially in ADR-resistant AML cells. Multidrug resistance protein 1 (MDR1)/p-glycoprotein (P-gp) levels were significantly increased in ADR-resistant AML cells, compared with parental AML cells. CRNDE down-regulation inhibited cell proliferation, promoted apoptosis, reduced Ki67 expression and enhanced cleaved caspase-3 expression in AML and ADR-resistant AML cells. In addition, CRNDE knockdown led to down-regulation of P-gp/MDR1, β-catenin, c-Myc and cyclinD1 expression, and enhanced the drug sensitivity to ADR in ADR-resistant AML cells. In conclusion, knockdown of CRNDE suppresses proliferation and P-gp-mediated MDR in ADR-resistant AML cells via inhibiting the Wnt/β-catenin pathway, suggesting that repression of CRNDE might be a therapeutic target to reverse MDR of ADR-resistant AML cells.

Artemisinin-type drugs for the treatment of hematological malignancies

Qinghaosu, known as artemisinin (ARS), has been for over two millennia, one of the most common herbs prescribed in traditional Chinese medicine (TCM). ARS was developed as an antimalarial drug and currently belongs to the established standard treatments of malaria as a combination therapy worldwide. In addition to the antimalarial bioactivity of ARS, anticancer activities have been shown both in vitro and in vivo. Like other natural products, ARS acts in a multi-specific manner also against hematological malignancies. The chemical structure of ARS is a sesquiterpene lactone, which contains an endoperoxide bridge essential for activity. The main mechanism of action of ARS and its derivatives (artesunate, dihydroartemisinin, artemether) toward leukemia, multiple myeloma, and lymphoma cells comprises oxidative stress response, inhibition of proliferation, induction of various types of cell death as apoptosis, autophagy, ferroptosis, inhibition of angiogenesis, and signal transducers, as NF-κB, MYC, amongst others. Therefore, new pharmaceutically active compounds, dimers, trimers, and hybrid molecules, could enhance the existing therapeutic alternatives in combating hematologic malignancies. Owing to the high potency and good tolerance without side effects of ARS-type drugs, combination therapies with standard chemotherapies could be applied in the future after further clinical trials in hematological malignancies.

Inhibition of cell migration and induction of apoptosis by a novel class II histone deacetylase inhibitor, MCC2344

Epigenetic modifiers provide a new target for the development of anti-cancer drugs. The eraser histone deacetylase 6 (HDAC6) is a class IIb histone deacetylase that targets various non-histone proteins such as transcription factors, nuclear receptors, cytoskeletal proteins, DNA repair proteins, and molecular chaperones. Therefore, it became an attractive target for cancer treatment. In this study, virtual screening was applied to the MicroCombiChem database with 1162 drug-like compounds to identify new HDAC6 inhibitors. Five compounds were tested in silico and in vitro as HDAC6 inhibitors. Both analyses revealed 1-cyclohexene-1-carboxamide, 2-hydroxy-4,4-dimethyl-N-1-naphthalenyl-6-oxo- (MCC2344) as the best HDAC6 inhibitor among the five ligands. The binding affinity of MCC2344 to HDAC6 was further confirmed by microscale thermophoresis. Additionally, the anti-cancer activity of MCC2344 was tested in several tumor cell lines. Leukemia cells were the most sensitive cells towards MCC2344, particularly the P-glycoprotein-overexpressing multidrug-resistant cell line CEM/ADR5000 exhibited remarkable collateral sensitivity towards MCC2344. Transcriptome analysis using microarray hybridization was performed for investigating downstream mechanisms of action of MCC2344 in leukemia cells. MCC2344 affected microtubule dynamics and suppressed cell migration in the wound healing assay as well as in a spheroid model by hyper-acetylation of tubulin and HSP-90. MCC2344 induced cell death in CEM/ADR5000 cells by activation of PARP, caspase-3, and p21 in addition to the downregulation of p62. MCC2344 significantly inhibited tumor growth in vivo in zebrafish larvae without mortality until 20 pM. We propose MCC2344 as a novel HDAC6 inhibitor for cancer treatment.

Wnt-β-catenin Signaling Pathway, the Achilles' Heels of Cancer Multidrug Resistance

BACKGROUND

Most of the anticancer chemotherapies are hampered via the development of multidrug resistance (MDR), which is the resistance of tumor cells against cytotoxic effects of multiple chemotherapeutic agents. Overexpression and/or over-activation of ATP-dependent drug efflux transporters is a key mechanism underlying MDR development. Moreover, enhancement of drug metabolism, changes in drug targets and aberrant activation of the main signaling pathways, including Wnt, Akt and NF-κB are also responsible for MDR.

METHODS

In this study, we have reviewed the roles of Wnt signaling in MDR as well as its potential therapeutic significance. Pubmed and Scopus have been searched using Wnt, β-catenin, cancer, MDR and multidrug resistance as keywords. The last search was done in March 2019. Manuscripts investigating the roles of Wnt signaling in MDR or studying the modulation of MDR through the inhibition of Wnt signaling have been involved in the study. The main focus of the manuscript is regulation of MDR related transporters by canonical Wnt signaling pathway.

RESULT AND CONCLUSION

Wnt signaling has been involved in several pathophysiological states, including carcinogenesis and embryonic development. Wnt signaling is linked to various aspects of MDR including P-glycoprotein and multidrug resistance protein 1 regulation through its canonical pathways. Aberrant activation of Wnt/β- catenin signaling leads to the induction of cancer MDR mainly through the overexpression and/or over-activation of MDR related transporters. Accordingly, Wnt/β-catenin signaling can be a potential target for modulating cancer MDR.

The multiple ways Wnt signaling contributes to acute leukemia pathogenesis

WNT proteins constitute a very conserved family of secreted glycoproteins that act as short-range ligands for signaling with critical roles in hematopoiesis, embryonic development, and tissue homeostasis. These proteins transduce signals via the canonical pathway, which is β-catenin-mediated and better-characterized, or via more diverse noncanonical pathways that are β-catenin independent and comprise the planar cell polarity (PCP) pathway and the WNT/Ca⁺⁺ pathways. Several proteins regulate Wnt signaling through a variety of sophisticated mechanisms. Disorders within the pathway can contribute to various human diseases, and the dysregulation of Wnt pathways by different molecular mechanisms is implicated in the pathogenesis of many types of cancer, including the hematological malignancies. The types of leukemia differ considerably and can be subdivided into chronic, myeloid or lymphocytic, and acute, myeloid or lymphocytic, leukemia, according to the differentiation stage of the predominant cells, the progenitor lineage, the diagnostic age strata, and the specific molecular drivers behind their development. Here, we review the role of Wnt signaling in normal hematopoiesis and discuss in detail the multiple ways canonical Wnt signaling can be dysregulated in acute leukemia, including alterations in gene expression and protein levels, epigenetic regulation, and mutations. Furthermore, we highlight the different impacts of these alterations, considering the distinct forms of the disease, and the therapeutic potential of targeting Wnt signaling.

Antiepileptic Drug Carbamazepine Binds to a Novel Pocket on the Wnt Receptor Frizzled-8

Misregulation of Wnt signaling is common in human cancer. The development of small molecule inhibitors against the Wnt receptor, frizzled (FZD), may have potential in cancer therapy. During small molecule screens, we observed binding of carbamazepine to the cysteine-rich domain (CRD) of the Wnt receptor FZD8 using surface plasmon resonance (SPR). Cellular functional assays demonstrated that carbamazepine can suppress FZD8-mediated Wnt/β-catenin signaling. We determined the crystal structure of the complex at 1.7 Å resolution, which reveals that carbamazepine binds at a novel pocket on the FZD8 CRD. The unique residue Tyr52 discriminates FZD8 from the closely related FZD5 and other FZDs for carbamazepine binding. The first small molecule-bound FZD structure provides a basis for anti-FZD drug development. Furthermore, the observed carbamazepine-mediated Wnt signaling inhibition may help to explain the phenomenon of bone loss and increased adipogenesis in some patients during long-term carbamazepine treatment.

Identification of inhibitors of the polo-box domain of polo-like kinase 1 from natural and semisynthetic compounds

PLK1 has an important role in the regulation of cell cycle and represents an important target for cancer treatment. This enzyme belongs to the Polo-like kinases family, which is characterized by a regulatory domain named Polo-box domain (PBD). Rather than regular kinase inhibitors, this domain provides high selectivity to PLK1. Here, we report on four novel PLK1 PBD inhibitors identified by cytotoxicity screening and fluorescence polarization assay of a chemical library of natural and semisynthetic compounds. These compounds revealed two- to three-fold higher selectivity to the PDB of PLK1 than to those of the related family members, PLK2 and PLK3. These four substances inhibited tumor cell growth of sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. The tested compounds increased the apoptotic cell fraction, which indicates apoptosis as a major mechanism of cell death. Cell cycle analysis showed compound (5) arrested the cell cycle of CCRF-CEM cells in the G2/M phase, while the other three molecules ((compound (3), compound (4), and compound (6)) exerted pronounced cytotoxicity with an increase of cells in the sub-G1 population. Molecular docking was performed for the understanding of ligand-protein interaction, the tested candidates showed strong binding affinity to PLK1 PBD. In conclusion, we identified four new chemical scaffolds that may serve as lead compounds for the development of selective PLK1 inhibitors in the future.

MCC1019, a selective inhibitor of the Polo-box domain of Polo-like kinase 1 as novel, potent anticancer candidate

Polo-like kinase (PLK1) has been identified as a potential target for cancer treatment. Although a number of small molecules have been investigated as PLK1 inhibitors, many of which showed limited selectivity. PLK1 harbors a regulatory domain, the Polo box domain (PBD), which has a key regulatory function for kinase activity and substrate recognition. We report on 3-bromomethyl-benzofuran-2-carboxylic acid ethyl ester (designated: MCC1019) as selective PLK1 inhibitor targeting PLK1 PBD. Cytotoxicity and fluorescence polarization-based screening were applied to a library of 1162 drug-like compounds to identify potential inhibitors of PLK1 PBD. The activity of compound MC1019 against the PLK1 PBD was confirmed using fluorescence polarization and microscale thermophoresis. This compound exerted specificity towards PLK1 over PLK2 and PLK3. MCC1019 showed cytotoxic activity in a panel of different cancer cell lines. Mechanistic investigations in A549 lung adenocarcinoma cells revealed that MCC1019 induced cell growth inhibition through inactivation of AKT signaling pathway, it also induced prolonged mitotic arrest—a phenomenon known as mitotic catastrophe, which is followed by immediate cell death via apoptosis and necroptosis. MCC1019 significantly inhibited tumor growth in vivo in a murine lung cancer model without affecting body weight or vital organ size, and reduced the growth of metastatic lesions in the lung. We propose MCC1019 as promising anti-cancer drug candidate.

Comparison of the Effect of Native 1,4-Naphthoquinones Plumbagin, Menadione, and Lawsone on Viability, Redox Status, and Mitochondrial Functions of C6 Glioblastoma Cells

Background: 1,4-naphthoquinones, especially juglone, are known for their anticancer activity. However, plumbagin, lawsone, and menadione have been less investigated for these properties. Therefore, we aimed to determine the effects of plumbagin, lawsone, and menadione on C6 glioblastoma cell viability, ROS production, and mitochondrial function. Methods: Cell viability was assessed spectrophotometrically using metabolic activity method, and by fluorescent Hoechst/propidium iodide nuclear staining. ROS generation was measured fluorometrically using DCFH-DA. Oxygen uptake rates were recorded by the high-resolution respirometer Oxygraph-2k. Results: Plumbagin and menadione displayed highly cytotoxic activity on C6 cells (IC₅₀ is 7.7 ± 0.28 μM and 9.6 ± 0.75 μM, respectively) and caused cell death by necrosis. Additionally, they increased the amount of intracellular ROS in a concentration-dependent manner. Moreover, even at very small concentrations (1–3 µM), these compounds significantly uncoupled mitochondrial oxidation from phosphorylation impairing energy production in cells. Lawsone had significantly lower viability decreasing and mitochondria-uncoupling effect, and exerted strong antioxidant activity. Conclusions: Plumbagin and menadione exhibit strong prooxidant, mitochondrial oxidative phosphorylation uncoupling and cytotoxic activity. In contrast, lawsone demonstrates a moderate effect on C6 cell viability and mitochondrial functions, and possesses strong antioxidant properties.

Collateral Sensitivity of Parthenolide via NF-κB and HIF-α Inhibition and Epigenetic Changes in Drug-Resistant Cancer Cell Lines

Parthenolide (PT) is a sesquiterpene lactone isolated from Tanacetum parthenium. In this study, PT showed varying cytotoxic effects against different solid tumor cell lines. HCT116 (p53^+/+) colon carcinoma cells and their parental HCT116 knockout p53 (p53^-/-) cell lines showed a resistance degree of 2.36. On the other hand, wild-type U87.MG cells or cells transfected with a deletion-activated EGFR cDNA (U87.MGΔEGFR) exhibited slight sensitivity toward PT. Multidrug-resistant MDA-MB-231-BCRP cells were even more sensitive toward PT than sensitive MDA-MB-231-pcDNA cells with a resistance degree of 0.07 (collateral sensitivity). To the best of our knowledge, hypersensitivity (collateral sensitivity) in MDA-MB-231-BCRP cell line is reported in this study for the first time. We attempted to identify the mechanism of collateral sensitivity. Firstly, we found that PT bound to IKK preventing IκBα degradation and eventually inhibition of the nuclear factor kappa B (NF-κB) pathway. Down-regulation of hypoxia inducing factor 1-alpha (HIF-1α) in MDA-MB-231-BCRP resistant cells may be a second mechanism, since it is a target gene of NF-κB. Moreover, PT also showed epigenetic effect by inhibition of HDAC activity as shown using both molecular docking and HDAC activity assay. Based on COMPARE and hierarchical cluster analyses, we found gene expression profiles that predicted sensitivity or resistance of 47 tumor cell lines toward PT. Interestingly, pathway analyses of gene expression profiles revealed NF-κB and HIF signaling as top networks of these genes, cellular functions and canonical pathways influencing the activity of PT against tumor cells. In conclusion, PT exerted profound cytotoxic activity against various cancer cell lines mainly against BCRP-overexpressing tumor cells, suggesting PT as novel candidate for cancer treatment.

A selective inhibitor of the Polo-box domain of Polo-like kinase 1 identified by virtual screening

Polo-like kinase 1 (PLK1), a member of the Polo-like kinase family, plays an important regulatory role in mitosis and cell cycle progression. PLK1 overexpression is correlated with tumourigenesis and poor prognosis in cancer patients. Therefore, the identification of novel compounds that inhibit PLK1 would provide attractive therapeutic approaches. Although some PLK1 kinase inhibitors have been developed, their application has been limited by off-target effects. PLK1 contains a regulatory domain named the Polo-box domain (PBD), which is characteristic only for the Polo-like kinase family. This domain represents an alternative therapeutic target with higher selectivity for PLK1. In this study, we applied in silico virtual drug screening, fluorescence polarization and microscale thermophoresis to identify new scaffolds targeting the PBD of PLK1. One compound, 3-{[(1R,9S)-3-(naphthalen-2-yl)-6-oxo-7,11-diazatricyclo[7.3.1.02,7]trideca-2,4-dien-11-yl]methyl}benzonitrile (designated compound (1)), out of a total of 30,793 natural product derivatives, inhibited the PLK1 PBD with high selectivity (IC50: 17.9 ± 0.5 µM). This compound inhibited the growth of cultured leukaemia cells (CCRF-CEM and CEM/ADR5000) and arrested the cell cycle in the G2/M phase, which is characteristic for PLK1 inhibitors. Immunofluorescence analyses showed that treatment with compound (1) disrupted spindle formation due to the aberrant localization of PLK1 during the mitotic process, leading to G2/M arrest and ultimately cell death. In conclusion, compound (1) is a selective PLK1 inhibitor that inhibits cancer cell growth. It represents a chemical scaffold for the future synthesis of new selective PLK1 inhibitors for cancer therapy.

Dysregulation of miR-335-3p, targeted by NEAT1 and MALAT1 long non-coding RNAs, is associated with poor prognosis in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most prevalent cancer among children, and multidrug efflux mediated by overexpression of ABC transporters is the major impediment to successful chemotherapy in this malignancy. The goal of this study is to identify the non-coding RNAs (ncRNAs) which may affect the expression levels of ABCA3; the previously identified prognostic biomarker for multidrug resistance (MDR) in childhood ALL (cALL). Bone marrow samples from 64 cALLs, including 46 de novo and 18 relapsed patients, in addition to 30 non-cancer controls were collected, and ncRNAs were nominated using in silico studies. Quantitative RT-PCR showed low expression profiles of miR-335-3p in cALLs compared with the control group (P = 0.018). Inverse correlation was determined between the miR-335-3p and ABCA3 mRNA expression profiles in cALL patients (r = 0.5019, P = 0.002). Moreover, it was shown that the expression levels of miR-335-3p was downregulated in the drug-resistant samples (MDR group) compared with the drug-sensitive patients (mrd- group), (P = 0.0005, AUC = 0.801). On the other hand, negative correlations were identified between the expression levels of miR-335-3p and the selected LncRNAs, NEAT1 and MALAT1, in the MDR group compared with the mrd- patients (P = 0.009), suggesting a sponge effect for these LncRNAs. The current study showed a potential regulatory role for miR-335-3p in ABCA3 expression targeted by NEAT1 and MALAT1 long non-coding RNAs. This negative impact may possibly contribute to the development of chemoresistance in childhood ALL, and provide an exceptional insight to new therapeutic approaches.

GSK-3β Inhibitor Alsterpaullone Attenuates MPP+-Induced Cell Damage in a c-Myc-Dependent Manner in SH-SY5Y Cells

Mitochondrial dysfunction plays significant roles in the pathogenesis of Parkinson’s Disease (PD). The inactivation of c-Myc, a down-stream gene of Wnt/β-catenin signaling, may contribute to the mitochondria dysfunction. Inhibition of glycogen synthase kinase 3β (GSK-3β) with Alsterpaullone (Als) can activate the down-stream events of Wnt signaling. Here, we investigated the protective roles of Als against MPP⁺-induced cell apoptosis in SH-SY5Y cells. The data showed that Als effectively rescued c-Myc from the MPP⁺-induced decline via Wnt signaling. Furthermore, Als protected SH-SY5Y cells from the MPP⁺-induced mitochondrial fission and cell apoptosis. However, the protective roles of Als were lost under β-catenin-deficient conditions. These findings indicate that Als, a GSK-3β inhibitor, attenuated the MPP⁺-induced mitochondria-dependent apoptotic via up-regulation of the Wnt signaling.

Metal Complexes of Natural Product Like-compounds with Antitumor Activity

Cancer continues to be one of the major causes of death worldwide. Despite many advances in the understanding of this complex disease, new approaches are needed to improve the efficacy of current therapeutic treatments against aggressive tumors. Natural products are one of the most consistently successful sources of drug leads. In recent decades, research activity into the clinical potential of this class of compounds in cancer has increased. Furthermore, a highly promising field is the use of metals and their complexes in the design and development of metal-based drugs for the treatment of cancer. Metal complexes offer unique opportunities due to their ability to alter pharmacology, improving the efficacy and/or reducing the negative side effects of drug molecules. In addition, transition metals as copper, iron, and manganese, among others, can interact with active sites of enzymes, playing important roles in multiple biological processes. Thus, these complexes not only possess higher activities but also reach their targets more efficiently. This review article highlights recent advances on the emerging and expanding field of metal-based drugs. The emphasis is on new therapeutic strategies consisting of metal complexes with natural product like-compounds as a starting point for the rational design of new antitumor agents.