The Anti-Tumor Activity of Succinyl Macrolactin A Is Mediated through the β-Catenin Destruction Complex via the Suppression of Tankyrase and PI3K/Akt

High-efficiency breeding of Bacillus siamensis with hyper macrolactins production using physical mutagenesis and a high-throughput culture system

Macrolactins have attracted considerable attention due to their value and application in medicine and agriculture. However, poor yields severely hinder their broader application in these fields. This study aimed to improve macrolactins production in Bacillus siamensis using a combined atmospheric and room-temperature plasma mutagenesis and a microbial microdroplet culture system. After 25 days of treatment, a desirable strain with macrolactins production 3.0-fold higher than that of the parental strain was successfully selected. The addition of 30 mg/L ZnSO4 further increased macrolactins production to 503 ± 37.6 μg/mL, representing a 30.9 % improvement in production compared to controls. Based on transcriptome analysis, the synthesis pathways of amino acids, fengycin, and surfactin were found to be downregulated in IMD4036. Further fermentation experiments confirmed that inhibition of the comparative fengycin synthesis pathway was potentially driving the increased production of macrolactins. The strategies and possible mechanisms detailed in this study can provide insight into enhancing the production of other secondary metabolites toxic to the producer strains.

PI3K and tankyrase inhibitors as therapeutic targets in colorectal cancer

INTRODUCTION

The pathways like Wingless-related integration (Wnt/β-catenin) and PI3K play an important role in colorectal cancer (CRC) development; however, their roles are distinct in the process of oncogenesis. Despite their differences, these pathways interact through feedback mechanisms and regulate the common effectors both in the upstream and the downstream processes in normal and pathological conditions. Their ability to reciprocally control each other is a primary resistance mechanism for the selective inhibitors in CRC.

AREA COVERED

This review highlights the Wnt/β-catenin and PI3K pathways that are interrelated in CRC, recent advances and some key perspectives in developing inhibitors that could target the tankyrase enzyme and PI3K, apart from a brief description of the potential of dual inhibitors of PI3K and Tankyrases (TNKS).

EXPERT OPINION

Recent research has focused on overcoming the challenges particularly relating to the resistance and efficacy of dual inhibitors targeting PI3K and tankyrase proteins. Despite these challenges, PI3K as well as tankyrases remain promising therapeutic targets for the treatment of solid tumors. The design of potent inhibitors is crucial to effectively block these protein signaling pathways. Moreover, it is essential to explore the potential of dual-target inhibition of other signaling pathways in conjunction with PI3K and tankyrase.

UV-ARTP compound mutagenesis breeding improves macrolactins production of Bacillus siamensis and reveals metabolism changes by proteomic

Macrolactins are a type of compound with complex macrolide structure which mainly be obtained through microbiological fermentation now. They have excellent antifungal, antibacterial and antitumor activity. In order to improve macrolactins production, Bacillus siamensis YB304 was used as the research object, and a mutant Mut-K53 with stable genetic characters was selected by UV-ARTP compound mutagenesis. The yield of macrolactins was 156.46 mg/L, 3.95 times higher than original strain. The metabolic pathway changes and regulatory mechanism of macrolactins were analyzed by quantitative proteomics combined with parallel reaction monitoring. This study revealed that 1794 proteins were extracted from strain YB304 and strain Mut-K53, most of them were related to metabolism. After UV-ARTP compound mutagenesis treatment, the expression of 628 proteins were significantly changed, of which 299 proteins were significantly up-regulated. KEGG pathway analysis showed that differentially expression proteins mainly distributed in biological process, cellular component, and molecular function processing pathways. Such as utilization of carbon sources, glycolysis pathway, and amino acid metabolism pathway. Furthermore, key precursor substances such as acyl-CoA and amino acids of macrolactin biosynthesis are mostly up-regulated, which are one of the main reasons for increased production of macrolactin.This study will provide a new way to increase the yield of macrolactins through mutagenesis breeding and proteomics.

Pyridine-Based 1,2,4-Triazolo-Tethered Indole Conjugates Potentially Affecting TNKS and PI3K in Colorectal Cancer

A library of pyridine-based 1,2,4-triazolo-tethered indole conjugates were designed, synthesized, and evaluated for anti-proliferative activity against a panel of six human cancer cell lines. All the synthesized conjugates (14a-q) were found to be effective against the HT-29 cell line. Particularly conjugates 14a, 14n, and 14q exhibited promising cytotoxicity, with IC50 values of 1 μM, 2.4 μM, and 3.6 μM, respectively, compared to the standard 5-fluorouracil (IC50 = 5.31 μM). Cell cycle arrest at the G0/G1 phase was observed with these compounds, the mitochondrial membrane potential was interrupted, and the total ROS production was enhanced. Western blot and immunofluorescence experiments illustrated that these compounds inhibit the expression of markers that are involved in β-catenin and PI3K pathways. Molecular dynamics simulations demonstrated that compound 14a has major hydrophobic interactions and few H-bonding interactions with both PI3K and tankyrase proteins.

Classification and Multifaceted Potential of Secondary Metabolites Produced by Bacillus subtilis Group: A Comprehensive Review

Despite their remarkable biosynthetic potential, Bacillus subtilis have been widely overlooked. However, their capability to withstand harsh conditions (extreme temperature, Ultraviolet (UV) and γ-radiation, and dehydration) and the promiscuous metabolites they synthesize have created increased commercial interest in them as a therapeutic agent, a food preservative, and a plant-pathogen control agent. Nevertheless, the commercial-scale availability of these metabolites is constrained due to challenges in their accessibility via synthesis and low fermentation yields. In the context of this rising in interest, we comprehensively visualized the antimicrobial peptides produced by B. subtilis and highlighted their prospective applications in various industries. Moreover, we proposed and classified these metabolites produced by the B. subtilis group based on their biosynthetic pathways and chemical structures. The biosynthetic pathway, bioactivity, and chemical structure are discussed in detail for each class. We believe that this review will spark a renewed interest in the often disregarded B. subtilis and its remarkable biosynthetic capabilities.

Synthesis and Cytotoxic Activity of 1,2,4-Triazolo-Linked Bis-Indolyl Conjugates as Dual Inhibitors of Tankyrase and PI3K

A series of new 1,2,4-triazolo-linked bis-indolyl conjugates (15a–r) were prepared by multistep synthesis and evaluated for their cytotoxic activity against various human cancer cell lines. It was observed that they were more susceptible to colon and breast cancer cells. Conjugates 15o (IC₅₀ = 2.04 μM) and 15r (IC₅₀ = 0.85 μM) illustrated promising cytotoxicity compared to 5-fluorouracil (5-FU, IC₅₀ = 5.31 μM) against the HT-29 cell line. Interestingly, 15o and 15r induced cell cycle arrest at the G₀/G₁ phase and disrupted the mitochondrial membrane potential. Moreover, these conjugates led to apoptosis in HT-29 at 2 μM and 1 μM, respectively, and also enhanced the total ROS production as well as the mitochondrial-generated ROS. Immunofluorescence and Western blot assays revealed that these conjugates reduced the expression levels of the PI3K-P85, β-catenin, TAB-182, β-actin, AXIN-2, and NF-κB markers that are involved in the β-catenin pathway of colorectal cancer. The results of the in silico docking studies of 15r and 15o further support their dual inhibitory behaviour against PI3K and tankyrase. Interestingly, the conjugates have adequate ADME-toxicity parameters based on the calculated results of the molecular dynamic simulations, as we found that these inhibitors (15r) influenced the conformational flexibility of the 4OA7 and 3L54 proteins.

Marine biome-derived secondary metabolites, a class of promising antineoplastic agents: A systematic review on their classification, mechanism of action and future perspectives

Cancer is one of the most deadly diseases on the planet. Over the past decades, numerous antineoplastic compounds have been discovered from natural resources such as medicinal plants and marine species as part of multiple drug discovery initiatives. Notably, several marine flora (e.g. Ascophyllum nodosum, Sargassum thunbergii) have been identified as a rich source for novel cytotoxic compounds of different chemical forms. Despite the availability of enormous chemically enhanced new resources, the anticancer potential of marine flora and fauna has received little attention. Interestingly, numerous marine-derived secondary metabolites (e.g., Cytarabine, Trabectedin) have exhibited anticancer effects in preclinical cancer models. Most of the anticancer drugs obtained from marine sources stimulated apoptotic signal transduction pathways in cancer cells, such as the intrinsic and extrinsic pathways. This review highlights the sources of different cytotoxic secondary metabolites obtained from marine bacteria, algae, fungi, invertebrates, and vertebrates. Furthermore, this review provides a comprehensive overview of the utilisation of numerous marine-derived cytotoxic compounds as anticancer drugs, as well as their modes of action (e.g., molecular target). Finally, it also discusses the future prospects of marine-derived drug developments and their constraints.

Therapeutic Potential of Fingolimod and Dimethyl Fumarate in Non-Small Cell Lung Cancer Preclinical Models

New therapies are required for patients with non-small cell lung cancer (NSCLC) for which the current standards of care poorly affect the patient prognosis of this aggressive cancer subtype. In this preclinical study, we aim to investigate the efficacy of Fingolimod, a described inhibitor of sphingosine-1-phosphate (S1P)/S1P receptors axis, and Dimethyl Fumarate (DMF), a methyl ester of fumaric acid, both already approved as immunomodulators in auto-immune diseases with additional expected anti-cancer effects. The impact of both drugs was analyzed with in vitro cell survival analysis and in vivo graft models using mouse and human NSCLC cells implanted in immunocompetent or immunodeficient mice, respectively. We demonstrated that Fingolimod and DMF repressed tumor progression without apparent adverse effects in vivo in three preclinical mouse NSCLC models. In vitro, Fingolimod did not affect either the tumor proliferation or the cytotoxicity, although DMF reduced tumor cell proliferation. These results suggest that Fingolimod and DMF affected tumor progression through different cellular mechanisms within the tumor microenvironment. Fingolimod and DMF might uncover potential therapeutic opportunities in NSCLC.

Albuca Bracteate Polysaccharides Synergistically Enhance the Anti-Tumor Efficacy of 5-Fluorouracil Against Colorectal Cancer by Modulating β-Catenin Signaling and Intestinal Flora

The first-line treatment for colorectal cancer (CRC) is 5-fluorouracil (5-FU). However, the efficacy of this treatment is sometimes limited owing to chemoresistance as well as treatment-associated intestinal mucositis and other adverse events. Growing evidence suggests that certain phytochemicals have therapeutic and cancer-preventing properties. Further, the synergistic interactions between many such plant-derived products and chemotherapeutic drugs have been linked to improved therapeutic efficacy. Polysaccharides extracted from Albuca bracteata (Thunb.) J.C.Manning and Goldblatt (ABP) have been reported to exhibit anti-oxidant, anti-inflammatory, and anti-tumor properties. In this study, murine CRC cells (CT26) and a murine model of CRC were used to examine the anti-tumor properties of ABP and explore the mechanism underlying the synergistic interactions between ABP and 5-FU. Our results revealed that ABP could inhibit tumor cell proliferation, invasion, and migratory activity in vitro and inhibited tumor progression in vivo by suppressing β-catenin signaling. Additionally, treatment with a combination of ABP and 5-FU resulted in better outcomes than treatment with either agent alone. Moreover, this combination therapy resulted in the specific enrichment of Ruminococcus, Anaerostipes, and Oscillospira in the intestinal microbiota and increased fecal short-chain fatty acid (SCFA) levels (acetic acid, propionic acid, and butyric acid). The improvement in the intestinal microbiota and the increase in beneficial SCFAs contributed to enhanced therapeutic outcomes and reduced the adverse effects of 5-FU. Together, these data suggest that ABP exhibits anti-neoplastic activity and can effectively enhance the efficacy of 5-FU in CRC treatment. Therefore, further research on the application of ABP in the development of novel anti-tumor drugs and adjuvant compounds is warranted and could improve the outcomes of CRC patients.

Schistosoma mansoni eggs induce Wnt/β-catenin signaling and activate the protooncogene c-Jun in human and hamster colon

Schistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia, in sub-Saharan Africa, and particularly also in Europe. The WHO describes an increasing global health burden with more than 290 million people threatened by the disease and a potential to spread into regions with temperate climates like Corsica, France. The aim of our study was to investigate the influence of S. mansoni infection on colorectal carcinogenic signaling pathways in vivo and in vitro. S. mansoni infection, soluble egg antigens (SEA) and the Interleukin-4-inducing principle from S. mansoni eggs induce Wnt/β-catenin signaling and the protooncogene c-Jun as well as downstream factor Cyclin D1 and markers for DNA-damage, such as Parp1 and γH2a.x in enterocytes. The presence of these characteristic hallmarks of colorectal carcinogenesis was confirmed in colon biopsies from S. mansoni-infected patients demonstrating the clinical relevance of our findings. For the first time it was shown that S. mansoni SEA may be involved in the induction of colorectal carcinoma-associated signaling pathways.

Marine Microorganism-Derived Macrolactins Inhibit Inflammatory Mediator Effects in LPS-Induced Macrophage and Microglial Cells by Regulating BACH1 and HO-1/Nrf2 Signals through Inhibition of TLR4 Activation

Recently, many natural products with unique structure and promising pharmacological potential have been reported from marine-derived microorganisms. The macrolactin A (MA), 15-epi-dihydromacrolactin F (DMF) and macrolactin F (MF) were obtained from the culture broth extract of a marine sediment derived microorganism Bacillus sp. HC001. In this study, MA, DMF and MF inhibited the production and expression of proinflammatory mediators of inducible nitric oxide synthase (iNOS) and cyclooxygenase–2 (COX-2) in LPS-stimulated RAW264.7 and BV2 cells. Also, MA, DMF and MF exert anti-inflammatory effects through the expression of heme oxygenase (HO) -1, a stress-inducing enzyme that converts heme to carbon monoxide (CO), iron and biliberdine. Toll-like receptor 4 (TLR4) expressed by lipopolysaccharide (LPS) was inhibited by increased expression of HO-1 transcription factor Nrf2 and down regulation of BTB Domain And CNC Homolog 1 (BACH1), inhibited phosphorylation of Mitogen-activated protein kinase kinase kinase 7 (MAP3K7, TAK1) and nuclear factor kappaB (NF-κB). These results show that MA, DMF and MF effectively inhibited TLR4 by regulating BACH1 and HO-1/Nrf2 signals in LPS-stimulated RAW264.7 and BV2 cells, which suggests the possibility of use as an anti-inflammatory agent.

Bioactive Secondary Metabolites from Bacillus subtilis: A Comprehensive Review

Bacillus subtilis is widely underappreciated for its inherent biosynthetic potential. This report comprehensively summarizes the known bioactive secondary metabolites from B. subtilis and highlights potential applications as plant pathogen control agents, drugs, and biosurfactants. B. subtilis is well known for the production of cyclic lipopeptides exhibiting strong surfactant and antimicrobial activities, such as surfactins, iturins, and fengycins. Several polyketide-derived macrolides as well as nonribosomal peptides, dihydroisocoumarins, and linear lipopeptides with antimicrobial properties have been reported, demonstrating the biosynthetic arsenal of this bacterium. Promising efforts toward the application of B. subtilis strains and their natural products in areas of agriculture and medicine are underway. However, industrial-scale availability of these compounds is currently limited by low fermentation yields and challenging accessibility via synthesis, necessitating the development of genetically engineered strains and optimized cultivation processes. We hope that this review will attract renewed interest in this often-overlooked bacterium and its impressive biosynthetic skill set.

Novel agent #2714 potently inhibits lung cancer growth by suppressing cell proliferation and by inducing apoptosis in vitro and in vivo

The use of small molecule compounds to inhibit cell proliferation is one of the most promising approaches in cancer therapy. In the present study, a cell viability assay, flow cytometry analysis, western blotting and mouse xenograft models were used to investigate the anticancer activities of #2714 and its underlying mechanisms in lung cancer. The present in vitro results suggested that #2714 significantly inhibited the viability of the human non-small cell lung cancer line SPC-A1 in a concentration- and time-dependent manner, with a half-maximal inhibitory concentration value of 5.54 µM after 48 h of treatment. Additionally, #2714 inhibited SPC-A1 cell proliferation via the Wnt/β-catenin pathway and by impairing mitochondrial membrane potential. The protein expression levels of Wnt 3a, Wnt 5a/b, phosphorylated (p)-β-catenin, p-glycogen synthase kinase 3β, and p-mitogen-activated protein kinase 14 were downregulated following treatment with #2714. Furthermore, using a mouse xenograft model, #2714 was identified to significantly inhibit tumor growth and to decrease cancer cell proliferation in vivo. #2714 may represent a novel effective anticancer compound targeting lung cancer cells. Additionally, #2714 was able to induce apoptosis and decrease cell proliferation in SPC-A1 cells via the Wnt/β-catenin pathway.

Microbial diversity of saline environments: searching for cytotoxic activities

In order to select halophilic microorganisms as a source of compounds with cytotoxic activities, a total of 135 bacterial strains were isolated from water and sediment samples collected from the Zipaquirá salt mine in the Colombian Andes. We determined the cytotoxic effects of 100 crude extracts from 54 selected organisms on the adherent murine mammary cell carcinoma 4T1 and human mammary adenocarcinoma MCF-7 cell lines. These extracts were obtained from strains of Isoptericola, Ornithinimicrobium, Janibacter, Nesterenkonia, Alkalibacterium, Bacillus, Halomonas, Chromohalobacter, Shewanella, Salipiger, Martellela, Oceanibaculum, Caenispirillum and Labrenzia. The extracts of 23 strains showed an IC₅₀ of less than 100 μg mL⁻¹. They were subsequently analyzed by LC/MS allowing dereplication of 20 compounds. The cytotoxic effect was related to a complex mixture of diketopiperazines present in many of the extracts analyzed. The greatest cytotoxic activity against both of the evaluated cell lines was obtained from the chloroform extract of Labrenzia aggregata USBA 371 which had an IC₅₀ < 6 μg mL⁻¹. Other extracts with high levels of cytotoxic activity were obtained from Bacillus sp. (IC₅₀ < 50 μg mL⁻¹) which contained several compounds such as macrolactin L and A, 7-O-succinoylmacrolactin F and iturin. Shewanella chilikensis USBA 344 also showed high levels of cytotoxic activity against both cell lines in the crude extract: an IC₅₀ < 15 μg mL⁻¹ against the 4T1 cell line and an IC₅₀ < 68 μg mL⁻¹ against the MCF-7 cell line. Nesterenkonia sandarakina CG 35, which has an IC₅₀ of 118 µg mL⁻¹ against 4T1, is a producer of diketopiperazines and 1-acetyl-β-carboline. Also, Ornithinimicrobium kibberense CG 24, which has IC₅₀ < 50 μg mL⁻¹, was a producer of diketopiperazines and lagunamycin. Our study demonstrates that these saline environments are habitats of halophilic and halotolerant bacteria that have previously unreported cytotoxic activity.

Combination therapy of 7-O-succinyl macrolactin A tromethamine salt and temozolomide against experimental glioblastoma

7-O-succinyl macrolactin A has shown anti-inflammatory, anti-angiogenesis, and anti-metastatic effects. It also exhibits strong suppression of tumor growth. In our previous study, we assessed the anti-neoplastic effects of 7-O-succinyl macrolactin A tromethamine salt (SMA salt) on a glioma cell line. Moreover, according to our data, SMA salt might be contributed to the inhibitory effects on migration and invasion, as well as a cytotoxic effect on the glioblastoma cell lines. In the present study, we investigated the anti-tumor effects of combination therapy with SMA salt and temozolomide (TMZ) in glioblastoma cell lines. The combination therapy affected cell viability significantly, decreasing in glioblastoma cell lines. In cell migration assays, combination therapy showed more inhibitory effects than TMZ in these cell lines. The tumor volume was significantly decreased in the combination group compared with both TMZ and control groups by using the orthotopic mouse model. The effects of combination therapy with SMA salt and TMZ attributed to the inhibition of migration, invasion activities and anti-tumor effects. SMA salt could be one of the promising candidates for combination therapy in clinical settings.

Calculation of a First-In-Man Dose of 7-O-Succinyl Macrolactin A Based on Allometric Scaling of Data from Mice, Rats, and Dogs

7-O-Succinyl macrolactin A (SMA) exerts several pharmacological effects including anti-bacterial, anti-inflammation, and anti-cancer activities. Recently, SMA has been extensively evaluated as an anti-cancer drug. Thus, the objectives of the present study were to characterise the pharmacokinetics of SMA via both non-compartmental and compartmental analysis in mice, rats, and dogs, and to derive an appropriate first-in-man dose based on allometric scaling of the animal data. The time courses of plasma SMA concentrations after intravenous administration to rats and dogs were analysed retrospectively, as were data collected after intraperitoneal SMA injection in mice. Pharmacokinetic parameters were estimated via both noncompartmental and compartmental analysis, and were correlated with body weight and/or the potential maximum life-span. The clearance and distribution volume of SMA in humans were predicted, and a first-in-man dose proposed. A two-compartment model best described the time courses of SMA plasma concentrations after a saturation elimination process was applied to fit the dataset obtained from rats. Incorporation of the maximum potential life-span during allometric scaling was required to improve the estimation of human clearance. The SMA clearance and the distribution volume in the steady state, in a 70-kg adult male, were estimated to be 30.6 L/h and 19.5 L, respectively. To meet the area under the curve (AUC) required for anti-tumour activity, a dose of 100 mg (∼1.5 mg/kg) was finally proposed as the first dose for a 70-kg human. Although toxicological profiles derived from non-clinical studies must be considered before any final decision is made, our work will facilitate clinical studies on SMA.

Antitumor activity of 7-O-succinyl macrolactin A tromethamine salt in the mouse glioma model

Chemoradiotherapy with temozolomide is the current standard treatment option for patients with glioblastoma. However, the majority of patients with glioblastoma survive for <2 years. Therefore, it is necessary to develop more effective therapeutic strategies for the treatment of glioblastoma. 7-O-succinyl macrolactin A tromethamine salt (SMA salt), a macrolactin compound, is known to possess an antiangiogenic activity. The present study investigated the antitumor effects of SMA salt in the treatment of glioblastoma by evaluating in vitro and in vivo antitumor effects of SMA salt in an experimental glioblastoma model. The antitumor effects of the drug on human glioblastoma U87MG, U251MG and LN229 cell lines were assessed using in vitro cell viability, migration and invasion assays. Nude mice with established U87MG glioblastoma were assigned to either the control or SMA salt treatment group. The volume of tumors and the duration of survival were also measured. SMA salt affected cell viability and caused a concentration-dependent inhibition effect on the migration and invasion of glioblastoma cell lines. Animals in the SMA salt treatment group demonstrated a significant reduction in tumor volume and an increase in survival (P<0.05). Treatment with SMA salt presented more cytotoxic effects as well as anti-migration and anti-invasion activity compared with the control group in vitro and in vivo. These results suggest that SMA salt has significant antitumor effects on glioblastoma.

Alcohol Injury Damages Intestinal Stem Cells

BACKGROUND

Alcohol consumption is associated with intestinal injury including intestinal leakiness and the risk of developing progressive gastrointestinal cancer. Alcoholics have disruption of intestinal barrier dysfunction that persists weeks after stopping alcohol intake, and this occurs in spite of the fact that intestinal epithelial cells turn over every 3 to 5 days. The renewal and functional regulation of the intestinal epithelium largely relies on intestinal stem cells (ISCs). Chronic inflammation and tissue damage in the intestine can injure stem cells including accumulation of mutations that may result in ISC dysfunction and transformation. ISCs are a key element in intestinal function and pathology; however, very little is known about the effects of alcohol on ISCs. We hypothesize that dysregulation of ISCs is one mechanism by which alcohol induces long-lasting intestinal damage.

METHODS

In Vivo: Small intestinal samples from alcohol- and control-fed mice were assessed for ISC markers (Lgr5 and Bmi1) and the changes of the β-catenin signaling using immunofluorescent microscopy, Western blotting, and RT-PCR. Ex Vivo: Organoids were generated from small intestine tissue and subsequently exposed to alcohol and analyzed for ISC markers, β-catenin signaling.

RESULTS

Chronic alcohol consumption significantly decreased the expression of stem cell markers, Bmi1 in the small intestine of the alcohol-fed mice and also resulted in dysregulation of the β-catenin signaling-an essential regulator of its target gene Lgr5 and ISC function. Exposure of small intestine-derived organoids to 0.2% alcohol significantly reduced the growth of the organoids, including budding, and total surface area of the organoid cultures. Alcohol also significantly decreased the expression of Lgr5, p-β-catenin (ser552), and Bmi1 in the organoid model.

CONCLUSIONS

Both chronic alcohol feeding and acute exposure of alcohol resulted in ISC dysregulation which might be one mechanism for alcohol-induced long-lasting intestinal damage.

Potential role of Wnt/β-catenin signaling in blastic transformation of chronic myeloid leukemia: cross talk between β-catenin and BCR-ABL

Chronic myeloid leukemia (CML) results from malignant transformation of hematopoietic stem cells induced by the BCR-ABL oncogene. Transformation from chronic to blastic phase is the lethal step in CML. Leukemic stem cells (LSCs) are the basic reason for blastic transformation. It has been shown that Wnt/β-catenin signaling contributes to the self-renewal capacity and proliferation of LSCs in CML. However, the role of Wnt/β-catenin signaling in blastic transformation of CML is still obscure. Here, we explored the relationship between BCR-ABL and β-catenin signaling in vitro and in vivo. We found that BCR-ABL stimulated β-catenin via activation of PI3K/AKT signaling in blastic phase CML cells. Inhibition of the kinase activity of BCR-ABL, PI3K, or AKT decreased the level of β-catenin in both K562 cells and a CML mouse model and suppressed the transcription of downstream target genes (c-myc and cyclin D1). In addition, inhibition of the BCR-ABL/PI3K/AKT pathway delayed the disease progression in the CML mouse model. To further explore the role of β-catenin in the self-renewal and survival of CML LSCs, we established a secondary transplantation CML mouse model. Our data revealed that inhibition of the BCR-ABL/PI3K/AKT pathway reduced the tumor-initiating ability of K562 cells, decreased leukemia cell infiltration into peripheral blood and bone marrow, and prolonged the survival of mice. In conclusion, our data indicate a close relationship between β-catenin and BCR-ABL/PI3K/AKT in blastic phase CML. β-Catenin inhibition may be of therapeutic value by targeting LSCs in combination with a tyrosine kinase inhibitor, which may delay blastic transformation of CML.

Multifunctional DDX3: dual roles in various cancer development and its related signaling pathways

DEAD-box RNA helicase 3 (DDX3) is a highly conserved family member of DEAD-box protein, which is a cluster of ATP-dependent and the largest family of RNA helicase. DEAD-box family is characterized by the regulation of ATPase and helicase activities, the modulation of RNA metabolism, and the actors of RNA binding proteins or molecular chaperones to interact with other proteins or RNA. For DDX3, it exerts its multifaceted roles in viral manipulation, stress response, hypoxia, radiation response and apoptosis, and is closely related to cancer development and progression. DDX3 has dual roles in different cancer types and can act as either an oncogene or tumor suppressor gene during cancer progression. In the present review, we mainly provide an overview of current knowledge on dual roles of DDX3 in various types of cancer, including breast cancer, lung cancer, colorectal cancer, hepatocellular carcinoma, oral squamous cell carcinoma, Ewing sarcoma, glioblastoma multiforme and gallbladder carcinoma, and illustrate the regulatory mechanisms for leading these two controversial biological effects. Furthermore, we summarize the essential signaling pathways that DDX3 participated, especially the Wnt/β-catenin signaling and EMT related signaling (TGF-β, Notch, Hedgehog pathways), which are crucial to DDX3 mediated cancer metastasis process. Thoroughly exploring the dual roles of DDX3 in cancer development and the essential signaling pathways it involved, it will help us open new perspectives to develop novel promising targets to elevate therapeutic effects and facilitate the "Personalized medicine" or "Precision medicine" to come into clinic.