Sulforhodamine B (SRB) Assay in Cell Culture to Investigate Cell Proliferation

Diverse Action of Selected Statins on Skeletal Muscle Cells-An Attempt to Explain the Protective Effect of Geranylgeraniol (GGOH) in Statin-Associated Myopathy (SAM)

The present study is centered on molecular mechanisms of the cytoprotective effect of geranylgeraniol (GGOH) in skeletal muscle harmed by statin-associated myopathy (SAM). GGOH via autophagy induction was purportedly assumed to prevent skeletal muscle viability impaired by statins, atorvastatin (ATR) or simvastatin (SIM). The C2C12 cell line was used as the ‘in vitro’ model of muscle cells at different stages of muscle formation, and the effect of ATR or SIM on the cell viability, protein expression and mitochondrial respiration were tested. Autophagy seems to be important for the differentiation of muscle cells; however, it did not participate in the observed GGOH cytoprotective effects. We showed that ATR- and SIM-dependent loss in cell viability was reversed by GGOH co-treatment, although GGOH did not reverse the ATR-induced drop in the cytochrome c oxidase protein expression level. It has been unambiguously revealed that the mitochondria of C2C12 cells are not sensitive to SIM, although ATR effectively inhibits mitochondrial respiration. GGOH restored proper mitochondria functioning. Apoptosis might, to some extent, explain the lower viability of statin-treated myotubes as the pan-caspase inhibitor, N-Benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-FMK), partly reversed ATR- or SIM-induced cytotoxic effects; however, it does not do so in conjunction with caspase-3. It appears that the calpain inhibitor, N-Acetyl-L-leucyl-L-leucyl-L-norleucinal (ALLM), restored the viability that was reduced by ATR and SIM (p< 0.001). GGOH prevents SAM, in part, as a consequence of a caspase-3 independent pathway, probably by calpain system inactivation.

Targeting Endometrial Cancer Stem Cell Activity with Metformin Is Inhibited by Patient-Derived Adipocyte-Secreted Factors

Advanced endometrial cancer continues to have a poor prognosis, due to limited treatment options, which may be further adversely impacted by obesity. Endometrial cancer stem cells have been reported to drive metastasis, chemotherapy resistance and disease relapse, but have yet to be fully characterised and no specific targeted therapies have been identified. Here, we describe the phenotype and genotype of aldehyde dehydrogenase high (ALDH^high) and CD133^+ve endometrial cancer stem cells and how adipocyte secreted mediators block the inhibitory effect of metformin on endometrial cancer stem cell activity. Ishikawa and Hec-1a cell lines were used to characterise ALDH^high and CD133^+ve endometrial cancer cells using flow cytometry, functional sphere assays and quantitative-Polymerase Chain Reaction. The comparative effect of metformin on endometrial cancer stem cell activity and bulk tumour cell proliferation was determined using an Aldefluor and cytotoxicity assay. The impact of adipocyte secreted mediators on metformin response was established using patient-derived conditioned media. ALDH^high cells demonstrated greater endometrial cancer stem cell activity than CD133^+ve cells and had increased expression of stem cell and epithelial-mesenchymal transition genes. Treatment with 0.5-1 mM metformin reduced the proportion and activity of both endometrial cancer stem cell populations (p ≤ 0.05), without affecting cell viability. This effect was, however, inhibited by exposure to patient-derived adipocyte conditioned media. These results indicate a selective and specific effect of metformin on endometrial cancer stem cell activity, which is blocked by adipocyte secreted mediators. Future studies of metformin as an adjuvant therapy in endometrial cancer should be adequately powered to investigate the influence of body mass on treatment response.

The deglycase activity of DJ-1 mitigates α-synuclein glycation and aggregation in dopaminergic cells: Role of oxidative stress mediated downregulation of DJ-1 in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder associated with the degeneration of dopamine neurons of the substantia nigra pars compacta (SNpc) and the presence of intra-neuronal aggregates of α-synuclein and its post-translational products. Based on emerging reports on the association between glycated α-synuclein and PD; and the newly identified deglycase activity of DJ-1, we sought to find the relevance of deglycase activity of DJ-1 on glycation of α-synuclein and its plausible role in PD. Our results demonstrate that DJ-1 has a higher affinity towards the substrate methylglyoxal (MGO) (Km = 900 mM) as compared to its familial mutant, L166P (Km = 1900 mM). Also, CML α-synuclein (CML-syn) served as a substrate for the deglycase activity of DJ-1. Treatment of cells with Parkinsonian mimetic, 1-methyl-4-phenylpyridinium ion (MPP⁺); oxidants, such as H₂O₂ and methylglyoxal (MGO) lead to a dose-dependent decrease in the levels of DJ-1 with a concomitant increase in CML-syn. Also, MGO induced cytosolic α-synuclein aggregates in cells which stained positive with the anti-CML antibody. Further, unilateral stereotaxic administration of MGO into the SNpc of mice induced α-synuclein aggregates and CML-syn with a concomitant reduction in the number of TH positive neurons, protein levels of TH and DJ-1 at the site of injection. Interestingly, overexpression of DJ-1 enhanced the clearance of preformed CML-syn in cells, mitigated MGO induced CML-syn and intracellular α-synuclein aggregates. Overall, the findings of our present study demonstrate that DJ-1 plays a pivotal role in the glycation and aggregation of α-synuclein. Reduced DJ-1 activity due to mutations or oxidative stress may lead to the accumulation of glycated α-synuclein and its aggregates.

Antitumor effects of all-trans retinoic acid and its synergism with gemcitabine are associated with downregulation of p21-activated kinases in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal malignancies worldwide. All-trans retinoic acid (ATRA) has been used as an antistromal agent in PDA, and its antitumor effect has also been reported in various kinds of cancer, including PDA. Inhibition of p21-activated kinases (PAKs) is associated with decreased tumor growth and increased gemcitabine sensitivity. The aim of this study was to evaluate the inhibitory effects of ATRA alone and in combination with gemcitabine on cell growth and migration of wild-type and gemcitabine-resistant PDA cells and the potential mechanism(s) involved. Human (MiaPaCa-2) and murine (TB33117) PDA cell lines were incubated in increasing concentrations of gemcitabine to establish resistant clones. Cell growth, clonogenicity, and migration/invasion were determined using a sulforhodamine B assay, a colony formation assay, and a Boyden chamber assay, respectively. Protein expression was measured by Western blotting. ATRA reduced cell proliferation, colony formation, and migration/invasion in both wild-type and gemcitabine-resistant cell lines. PAK1 expression was significantly increased in resistant cells. Cells treated with ATRA showed decreased expression of PAK1, PAK2, PAK4, and α-smooth muscle actin. The combination of ATRA and gemcitabine synergistically reduced cell growth in both wild-type and gemcitabine-resistant cell lines. Depletion of PAK1 enhanced ATRA sensitivity in MiaPaCa-2 cells. In conclusion, the antitumor effects of ATRA and its synergism with gemcitabine are associated with downregulation of PAKs. NEW & NOTEWORTHY The inhibitory effect of all-trans retinoic acid (ATRA) on cell proliferation, colony formation, and migration/invasion was associated with downregulation of p21-activated kinases (PAKs), and depletion of PAK1 enhanced ATRA sensitivity in MiaPaCa-2 cells. The combination of ATRA and gemcitabine synergistically reduced cell growth in both wild-type and gemcitabine-resistant pancreatic ductal adenocarcinoma cells. As an important prognostic marker, α-smooth muscle actin also can be downregulated by ATRA in pancreatic ductal adenocarcinoma cells.

Cell quality control mechanisms maintain stemness and differentiation potential of P19 embryonic carcinoma cells

Given the relatively long life of stem cells (SCs), efficient mechanisms of quality control to balance cell survival and resistance to external and internal stress are required. Our objective was to test the relevance of cell quality control mechanisms for SCs maintenance, differentiation and resistance to cell death. We compared cell quality control in P19 stem cells (P19SCs) before and after differentiation (P19dCs). Differentiation of P19SCs resulted in alterations in parameters involved in cell survival and protein homeostasis, including the redox system, cardiolipin and lipid profiles, unfolded protein response, ubiquitin-proteasome and lysosomal systems, and signaling pathways controlling cell growth. In addition, P19SCs pluripotency was correlated with stronger antioxidant protection, modulation of apoptosis, and activation of macroautophagy, which all contributed to preserve SCs quality by increasing the threshold for cell death activation. Furthermore, our findings identify critical roles for the PI3K-AKT-MTOR pathway, as well as autophagic flux and apoptosis regulation in the maintenance of P19SCs pluripotency and differentiation potential.Abbreviations: 3-MA: 3-methyladenine; AKT/protein kinase B: thymoma viral proto-oncogene; AKT1: thymoma viral proto-oncogene 1; ATG: AuTophaGy-related; ATF6: activating transcription factor 6; BAX: BCL2-associated X protein; BBC3/PUMA: BCL2 binding component 3; BCL2: B cell leukemia/lymphoma 2; BNIP3L: BCL2/adenovirus E1B interacting protein 3-like; CASP3: caspase 3; CASP8: caspase 8; CASP9: caspase 9; CL: cardiolipin; CTSB: cathepsin B; CTSD: cathepsin D; DDIT3/CHOP: DNA-damage inducible transcript 3; DNM1L/DRP1: dynamin 1-like; DRAM1: DNA-damage regulated autophagy modulator 1; EIF2AK3/PERK: eukaryotic translation initiation factor 2 alpha kinase 3; EIF2S1/eIF2α: eukaryotic translation initiation factor 2, subunit alpha; ERN1/IRE1α: endoplasmic reticulum to nucleus signaling 1; ESCs: embryonic stem cells; KRT8/TROMA-1: cytokeratin 8; LAMP2A: lysosomal-associated membrane protein 2A; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; NANOG: Nanog homeobox; NAO: 10-N-nonyl acridine orange; NFE2L2/NRF2: nuclear factor, erythroid derived 2, like 2; OPA1: OPA1, mitochondrial dynamin like GTPase; P19dCs: P19 differentiated cells; P19SCs: P19 stem cells; POU5F1/OCT4: POU domain, class 5, transcription factor 1; PtdIns3K: phosphatidylinositol 3-kinase; RA: retinoic acid; ROS: reactive oxygen species; RPS6KB1/p70S6K: ribosomal protein S6 kinase, polypeptide 1; SCs: stem cells; SOD: superoxide dismutase; SHC1-1/p66SHC: src homology 2 domain-containing transforming protein C1, 66 kDa isoform; SOX2: SRY (sex determining region Y)-box 2; SQSTM1/p62: sequestosome 1; SPTAN1/αII-spectrin: spectrin alpha, non-erythrocytic 1; TOMM20: translocase of outer mitochondrial membrane 20; TRP53/p53: transformation related protein 53; TUBB3/betaIII-tubulin: tubulin, beta 3 class III; UPR: unfolded protein response; UPS: ubiquitin-proteasome system.

Photobiomodulation enhancement of cell proliferation at 660 nm does not require cytochrome c oxidase

Photobiomodulation (PBM) therapy is based on the use of specific light parameters to promote tissue repair. Although demonstrated in different cell models and tissues, the mechanism by which photobiomodulation operates is not well understood. Previous studies suggested that the cell proliferation enhancement triggered by red and near-infrared PBM involves the activation of the mitochondrial respiratory chain enzyme cytochrome c oxidase (CCO). It was suggested that light in this range would displace inhibitory nitric oxide bound to CCO. To test this mechanism, we took advantage of cell lines lacking CCO, including a mouse line knockout for Cox10 (a gene required for the synthesis of heme a, the prosthetic group of CCO) and a human cell line with an mtDNA mutation in the tRNA Lysine gene, leading to mitochondrial protein synthesis impairment and the lack of three critical CCO subunits. In both models we showed the complete absence of assembled CCO. PBM (660 nm) was applied to these proliferating cells using various parameters. In most of the conditions tested, increased cell proliferation was associated with PBM in both control and CCO negative cells, demonstrating that CCO is not required for PBM enhancement of cellular proliferation. Additional experiments showed that PBM increased both ATP levels and citrate synthase activity and levels. These results showed that although metabolic changes are associated with PBM, CCO is not required for its cell proliferation enhancing effect.

Sulforaphane Cannot Protect Human Fibroblasts From Repeated, Short and Sublethal Treatments with Hydrogen Peroxide

A delicate balance of reactive oxygen species (ROS) exists inside the cell: when the mechanisms that control the level of ROS fail, the cell is in an oxidative stress state, a condition that can accelerate aging processes. To contrast the pro-aging effect of ROS, the supplementation of antioxidants has been recently proposed. Sulforaphane (SFN) is an isothiocyanate isolated from Brassica plants that has been shown to modulate many critical factors inside the cells helping to counteract aging processes. In the present work, we exposed human dermal fibroblast to short, sublethal and repeated treatments with hydrogen peroxide for eight days, without or in combination with low concentration of SFN. Hydrogen peroxide treatments did not affect the oxidative status of the cells, without any significant change of the intracellular ROS levels or the number of mitochondria or thiols in total proteins. However, our regime promoted cell cycle progression and cell viability, increased the anti-apoptotic factor survivin and increased DNA damage, measured as number of foci positive for γ -H2AX. On the other hand, the treatment with SFN alone seemed to exert a protective effect, increasing the level of p53, which can block the expansion of possible DNA damaged cells. However, continued exposure to SFN at this concentration could not protect the cells from stress induced by hydrogen peroxide.

High PKD2 predicts poor prognosis in lung adenocarcinoma via promoting Epithelial-mesenchymal Transition

Protein kinase D2 (PKD2) has been reported to be related with progression and invasion in various cancers. However, its prognostic value and the underlying mechanism in lung cancer remains unclear. Herein we evaluated the expression of PKD2 in lung adenocarcinoma and investigated its relationship with EMT. GSEA, TCGA and K-M plotter database were applied and revealed that high PKD2 expression predicted poor outcome and related with lymph nodes metastasis in lung cancer. IHC and qRT-PCR were performed and found PKD2 was elevated in lung adenocarcinoma and negatively related with OS (p = 0.015), PFS (p = 0.006) and the level of E-cadherin (p = 0.021). Experiment in lung adenocarcinoma cell lines demonstrated up-regulation of PKD2 led to high expression of mesenchymal markers (N-cadherin, vim, mmp9 et al.) and EMT transcription factors(zeb1, twist, snail), and the results were reversed when PKD2 was knocked down. Further investigation showed that abrogation of PKD2 inhibited A549 cell migration, invasion, proliferation and induced cell arrest in G2/M phase. We concluded that high expression of PKD2 was associated with poor prognosis and cancer progression in lung adenocarcinoma patients by promoting EMT.

Antrocin, a bioactive component from Antrodia cinnamomea, suppresses breast carcinogenesis and stemness via downregulation of β-catenin/Notch1/Akt signaling

BACKGROUND

We identified increased β-catenin and Atk expression was associated with drug resistance and poor prognosis in breast cancer patients using public databases. Antrocin treatment suppressed breast tumorigenesis and stemness properties.

HYPOTHESIS/PURPOSE

We aimed to provide preclinical evidence for antrocin, an active component of Antrodia cinnamomea, as a potential small-molecule drug for treating drug-resistant breast cancer.

METHODS

Various in vitro assays including SRB, Boyden chamber, colony formation, drug combination index and tumor sphere generation were used to determine the anti-cancer and stemness effects of antrocin. Mouse xenograft models were used to evaluate antrocin's effect in vivo.

RESULTS

Antrocin treatment suppressed the viability, migration colony formation and mammosphere generation. Antrocin-mediated anti-cancer effects were associated with the decreased expression of oncogenic and stemness markers such as β-catenin, Akt and Notch1. A sequential regimen of antrocin and paclitaxel synergistically inhibit breast cancer viability in vitro and in vivo.

CONCLUSION

Our preclinical evidence supports antrocin's ability of inhibiting tumorigenic and stemness properties in breast cancer cells. Further develop of antrocin should be encouraged; the combined use of antrocin and paclitaxel may also be considered for future clinical trials.

Anticancer, antimicrobial and antioxidant potential of sterically tuned bis-N-heterocyclic salts

The current study was conducted to evaluate the antimicrobial, antioxidant, antileishmanial and cytotoxic potential of designed derivatives of 1,1′-(1,3-phenylenebis(methylene))bis(3-alkyl/aryl-1H-benzimidazol-3-ium) salts. The antibacterial potential of the test compounds was investigated against Staphylococcus aureus, Pseudomonas aeruginosa and two methicillin-resistant S. aureus (MRSA) strains (MRSA10, MRSA11), where compound 6 showed the best results. For brine shrimp lethality bioassay (BSLB), compound 6 again showed up to 100% mortality at 200 μg/mL and 56.7% mortality at 6.25 μg/mL. Antileishmanial assay was performed against Leishmania tropica at 20 μg/mL dosage, where 6 showed the most promising activity with 16.26% survival (83.74% mortality; IC50=14.63 μg/mL). The anticancer potential of the selected benzimidazole derivatives was evaluated against two selected cell lines (human colorectal cancer, HCT-116 and breast adenocarcinoma, MCF-7) using sulforhodamine B (SRB) assay. Compound 6 was found to be the most effective cytotoxic compound with 75% inhibition of HCT-116 proliferation at 1 mg/mL concentration. Succinctly, 6 exhibited impressive pharmacological potential that might be attributed to its higher lipophilic character owing to the longer N-substituted alkyl chains when compared to the other test compounds.

Synthesis and Evaluation of Baylis-Hillman Reaction Derived Imidazole and Triazole Cinnamates as Antifungal Agents

Allylic acetates derived from Baylis-Hillman reaction undergo efficient nucleophilic isomerization with imidazoles and triazoles to provide imidazolylmethyl and triazolylmethyl cinnamates stereoselectively. Antifungal evaluation of these derivatives against Cryptococcus neoformans exhibits good minimum inhibitory concentration values. These compounds exhibit low toxicity in proliferating MCF-7 breast cancer cell line. Structure activity relationship studies indicate that halogenated aromatic derivatives provide better antifungal activity.

Hyaluronidase inhibits reactive adipogenesis and inflammation of colon and skin

In this study we evaluated the role of hyaluronan (HA) in reactive adipogenesis, a local expansion of preadipocytes that provides host defense by release of antimicrobial peptides. We observed that HA accumulated during maturation of adipocytes in vitro and was associated with increased expression of preadipocyte factor 1, zinc finger protein 423, and early B cell factor 1. Although HA is normally abundant in the extracellular matrix, a further increase in HA staining occurred in mice at sites of reactive adipogenesis following injury of colon by dextran sodium sulfate or injury of skin from infection with Staphylococcus aureus. HA also abundantly accumulated around adipocytes seen in the colons of patients with inflammatory bowel disease. This HA was necessary for adipocyte maturation because digestion of HA by administration of soluble hyaluronidase or transgenic expression of hyaluronidase 1 inhibited adipogenesis in vitro and in vivo. Furthermore, hyaluronidase also suppressed inflammation of both skin and colon and decreased antimicrobial peptide expression by developing preadipocytes. This resulted in increased bacterial transit across the epithelial barrier despite decreased tissue injury from inflammation. These observations suggest HA plays an important role in reactive adipogenesis and host defense after injury.

Properties of novel surfactin-derived biosurfactants obtained through solid-phase synthesis

Eight molecules, four peptides (SPs) and four lipopeptides (LPs) derived by rational design from surfactin, a well-known secreted biosurfactant from Bacillus subtilis, were produced employing Fmoc-based solid-phase synthesis. These new peptides were tested to evaluate their potential biosurfactant and biological activities, aiming at possible applications in industrial, biological, pharmaceutical, and medical use. Five molecules (SP1, SP2, SP4, LP5, and LP8) presented potential for medical uses, mainly due to their drug delivery properties as suggested by their synergistic activity with the antibiotic vancomycin against Staphylococcus aureus. All synthetic peptides showed low toxicity against Vero cell cultures, in assays of hemolysis, and in different cytotoxicity assays. In addition, we found that three peptides (SP1, LP6, and LP7) had potential technological and industrial use because of their emulsifying capacity, low toxicity, and ability to physically stabilize solutions. These novel molecules retained some properties of the parental molecule (surfactin, which was originally obtained through nonribosomal synthesis in Bacillus subtilis) but have the advantage of being linear peptides, which can be produced at large scales through the use of conventional heterologous protein expression protocols.

Software tools for cell culture-related 3D printed structures

Three-dimensional (3D) printing technology allowed fast and cheap prototype fabrication in numerous segments of industry and it also became an increasingly versatile experimental platform in life sciences. Yet, general purpose software tools to control printer hardware are often suboptimal for bioprinting applications. Here we report a package of open source software tools that we developed specifically to meet bioprinting requirements: Machine movements can be (i) precisely specified using high level programming languages, and (ii) easily distributed across a batch of tissue culture dishes. To demonstrate the utility of the reported technique, we present custom fabricated, biocompatible 3D-printed plastic structures that can control cell spreading area or medium volume, and exhibit excellent optical properties even at 50 ul sample volumes. We expect our software tools to be helpful not only to manufacture customized in vitro experimental chambers, but for applications involving printing cells and extracellular matrices as well.

Green Synthesis of Gold Nanoparticles Using Carrageenan Oligosaccharide and Their In Vitro Antitumor Activity

Gold nanoparticles (AuNPs) have been widely used in catalysis, photothermal therapy, and targeted drug delivery. Carrageenan oligosaccharide (CAO) derived from marine red algae was used as a reducing and capping agent to obtain AuNPs by an eco-friendly, efficient, and simple synthetic route for the first time. The synthetic conditions of AuNPs were optimized by response surface methodology (RSM), and the CAO-AuNPs obtained were demonstrated to be ellipsoidal, stable and crystalline by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The CAO-AuNPs showed localized surface plasmon resonance (LSPR) oscillation at about 530 nm with a mean diameter of 35 ± 8 nm. The zeta potential of CAO-AuNPs was around -20 mV, which was related to the negatively charged CAO around AuNPs. The CAO-AuNPs exhibited significant cytotoxic activities to HCT-116 and MDA-MB-231 cells, which could be a promising nanomaterial for drug delivery.

From the Clinical Problem to the Basic Research-Co-Culture Models of Osteoblasts and Osteoclasts

Bone tissue undergoes constant remodeling and healing when fracture happens, in order to ensure its structural integrity. In order to better understand open biological and clinical questions linked to various bone diseases, bone cell co-culture technology is believed to shed some light into the dark. Osteoblasts/osteocytes and osteoclasts dominate the metabolism of bone by a multitude of connections. Therefore, it is widely accepted that a constant improvement of co-culture models with both cell types cultured on a 3D scaffold, is aimed to mimic an in vivo environment as closely as possible. Although in recent years a considerable knowledge of bone co-culture models has been accumulated, there are still many open questions. We here try to summarize the actual knowledge and address open questions.

Osteogenic Effect and Cell Signaling Activation of Extremely Low-Frequency Pulsed Electromagnetic Fields in Adipose-Derived Mesenchymal Stromal Cells

Extremely low-frequency pulsed electromagnetic field (ELF-PEMF) devices have been used in the clinic for the treatment of bone disorders over the past 30 years. However, the underlying mechanism of which ELF-PEMFs exert an effect on tissues at a cellular level is not well understood. Hence, in this study, we explored the potential of different ELF-PEMF signals in modulating human adipose-derived mesenchymal stromal cells' (hAMSC) osteogenic capability. The cell proliferation rate was assessed using carboxyfluorescein succinimidyl ester (CFSE) method. The osteogenesis potential of cells was determined by alkaline phosphatase (ALP) activity, Alizarin-Red S staining, and RT-qPCR. Finally, the intracellular signaling pathway of a selected ELF-PEMF signal was examined using the PathScan Intracellular Signaling Array. Among the tested ELF-PEMF signals, program 20 (26 Hz) showed activation of the Akt and MAPK/ERK signaling cascade and significant upregulations of collagen I, alkaline phosphatase, and osteocalcin when compared to nonstimulated cells. This study demonstrates the potential of certain ELF-PEMF signal parameters to induce osteogenic differentiation of hAMSC and provides important clues in terms of the molecular mechanisms for the stimulation of osteogenic effects by ELF-PEMF on hAMSC.

EZH2 induces the expression of miR-1301 as a negative feedback control mechanism in triple negative breast cancer

Breast cancer is one of the most common malignancies in women. ERα, PR, and HER2 triple negative breast cancer (TNBC) is the current research focus because of the lack of effective targeted therapies. In our study, lentivirus systems were used to overexpress EZH2 and miR-1301 in TNBC cell lines. Western blot analysis and RT-qPCR were used to detect the protein and microRNA levels. The TCGA and Kaplan Meier plotter databases were used to analyze the EZH2 and miR-1301 expression levels in breast cancer. The effect of miR-1301 overexpression on cell proliferation, migration and colony formation were determined by using the sulforhodamine B (SRB) assay, wound healing assay and colony formation assay, respectively. Furthermore, an xenograft mouse model was used to investigate the function of miR-1301 overexpression in vivo. Finally, dual luciferase reporter assay was used to verify the binding site of EZH2 and miR-1301. We found that EZH2 induced the expression of miR-1301 in two TNBC cell lines, HCC1937 and HCC1806. Overexpression of miR-1301 suppressed TNBC cell proliferation, migration and colony formation, as well as the xenograft tumor growth in immunodeficient mice. Interestingly, miR-1301 inhibited the expression of EZH2 by binding to the 3'-UTR of EZH2 gene. These data suggest that EZH2 induces the expression of miR-1301 as a negative feedback control mechanism in TNBC.

Harmine, a dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) inhibitor induces caspase-mediated apoptosis in neuroblastoma

Background

Neuroblastoma (NB) is an early childhood malignancy that arises from the developing sympathetic nervous system. Harmine is a tricyclic β-carboline alkaloid isolated from the harmal plant that exhibits both cytostatic and cytotoxic effects. Harmine is capable of blocking the activities of dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) family proteins and mitogen-activated protein kinase. These kinases promote proliferation and inhibit apoptosis.

Methods

Four human NB cell lines were used to study the effects of harmine treatment: SKNBE and KELLY (MYCN-amplified) as well as SKNAS and SKNFI (MYCN non-amplified). The anti-cancer properties of harmine were examined by RealTime-Glo MT cell viability assays, caspase activity assays, PARP cleavage using Western blot analysis, and flow cytometry-based Annexin V detection. A molecular interaction model of harmine bound to the DYRK2 family kinase was generated by computational docking using X-ray structures. NB tumors from human patients were profiled for DYRK mRNA expression patterns and clinical correlations using the R2 platform.

Results

The IC₅₀ values for harmine after 72 h treatment were 169.6, 170.8, and 791.7 μM for SKNBE, KELLY, and SKNFI, respectively. Exposure of these NB cell lines to 100 μM of harmine resulted in caspase-3/7 and caspase-9 activation as well as caspase-mediated PARP cleavage and Annexin V-positive stained cells, as early as 24 h after treatment, clearly suggesting apoptosis induction, especially in MYCN-amplified cell lines. Elevated DYRK2 mRNA levels correlated with poor prognosis in a large cohort of NB tumors.

Conclusion

Harmine is a known inhibitor of DYRK family kinases. It can induce apoptosis in NB cell lines, which led us to investigate the clinical correlations of DYRK family gene expression in NB tumors. The patient results support our hypothesis that DYRK inhibition by harmine and the subsequent triggering of caspase-mediated apoptosis might present a novel approach to NB therapy.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0574-3) contains supplementary material, which is available to authorized users.

FolamiRs: Ligand-targeted, vehicle-free delivery of microRNAs for the treatment of cancer

MicroRNAs are small RNAs that negatively regulate gene expression posttranscriptionally. Because changes in microRNA expression can promote or maintain disease states, microRNA-based therapeutics are being evaluated extensively. Unfortunately, the therapeutic potential of microRNA replacement is limited by deficient delivery vehicles. In this work, microRNAs are delivered in the absence of a protective vehicle. The method relies on direct attachment of microRNAs to folate (FolamiR), which mediates delivery of the conjugated microRNA into cells that overexpress the folate receptor. We show that the tumor-suppressive FolamiR, FolamiR-34a, is quickly taken up both by triple-negative breast cancer cells in vitro and in vivo and by tumors in an autochthonous model of lung cancer and slows their progression. This method delivers microRNAs directly to tumors in vivo without the use of toxic vehicles, representing an advance in the development of nontoxic, cancer-targeted therapeutics.

Design, synthesis and biological evaluation of new carbazole derivatives as anti-cancer and anti-migratory agents

Based on the efficacy of EHop-016 as an inhibitor of migration and Rac1 activation, a new series of carbazole derivatives has been synthesized. Cytotoxic and anti-migratory effects of these compounds were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines. Preliminary investigations of their anticancer activity demonstrated that several compounds have moderate antiproliferative effects on cancer cell lines with GI50 values in the range of 13-50 µM. Furthermore, compounds 3b and 11b inhibit migration activity of metastatic cell line MDA-MB-231 by 32% and 34%, respectively. Compound 11b was shown to inhibit activation of the Rho GTPase Rac1 by 55% at 250 nM in both MDA-MB-231 and MDA-MB-435 cell lines. Compared with the IC50 of Rac1 inhibition by lead compound EHop-016 of 1.1 µM, compound 11b demonstrates 4X improved in vitro efficacy.

Controlling of N-alkylpolyamine analogue metabolism by selective deuteration

Replacing protium with deuterium is an efficient method to modulate drug metabolism. N-alkylated polyamine analogues are polyamine antimetabolites with proven anticancer efficacy. We have characterized earlier the preferred metabolic routes of N1,N12-diethylspermine (DESpm), N1-benzyl-N12-ethylspermine (BnEtSpm) and N1,N12-dibenzylspermine (DBSpm) by human recombinant spermine oxidase (SMOX) and acetylpolyamine oxidase (APAO). Here, we studied the above analogues, their variably deuterated counterparts and their metabolites as substrates and inhibitors of APAO, SMOX, semicarbazide-sensitive amine oxidase (SSAO), diamine oxidase (DAO) and monoamine oxidases. We found that targeted deuteration efficiently redirected the preferable cleavage site and suppressed reaction rate by APAO and SMOX in vitro We found a three- to six-fold decline in Vmax with moderate variable effect on Km when deuterium was located at the preferred hydrogen abstraction site of the analogue. We also found some of the metabolites to be potent inhibitors of DAO and SSAO. Surprisingly, analogue deuteration did not markedly alter the anti-proliferative efficacy of the drugs in DU145 prostate cancer cells, while in mouse embryonic fibroblasts, which had higher basal APAO and SMOX activities, moderate effect was observed. Interestingly, the anti-proliferative efficacy of the analogues did not correlate with their ability to suppress polyamine biosynthetic enzymes, induce spermidine/spermine-N1-acetyltransferase or deplete intracellular polyamine levels, but correlated with their ability to induce SMOX. Our data show that selective deuteration of N-alkyl polyamine analogues enables metabolic switching, offering the means for selective generation of bioactive metabolites inhibiting, e.g. SSAO and DAO, thus setting a novel basis for in vivo studies of this class of analogues.

Suppression of RANKL-Induced Osteoclastogenesis by the Metabolites from the Marine Fungus Aspergillus flocculosus Isolated from a Sponge Stylissa sp

A new α-pyrone merosesquiterpenoid possessing an angular tetracyclic carbon skeleton, ochraceopone F (1), and four known secondary metabolites, aspertetranone D (2), cycloechinulin (3), wasabidienone E (4), and mactanamide (5), were isolated from the marine fungus Aspergillus flocculosus derived from a sponge Stylissa sp. collected in Vietnam. The structures of Compounds 1–5 were elucidated by analysis of 1D and 2D NMR spectra and MS data. All the isolated compounds were evaluated for anti-proliferation activity and their suppression effects on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation using tartate-resisant acid phosphatase (TRAP). Compounds 1–5 had no anti-proliferative effect on human cancer cell lines up to 30 μg/mL. Among these compounds, aspertetranone D (2) and wasabidienone E (4) exhibited weak osteoclast differentiation inhibitory activity at 10 μg/mL. However, mactanamide (5) showed a potent suppression effect of osteoclast differentiation without any evidence of cytotoxicity.

Cell-based in vitro models in environmental toxicology: a review

An analysis of biological effects induced by environmental toxins and exposure-related evaluation of potential risks for health and environment represent central tasks in classical biomonitoring. While epidemiological data and population surveys are clearly the methodological frontline of this scientific field, cellbased in vitro assays provide information on toxin-affected cellular pathways and mechanisms, and are important sources for the identification of relevant biomarkers. This review provides an overview on currently available in vitro methods based on cultured cells, as well as some limitations and considerations that are of specific interest in the context of environmental toxicology. Today, a large number of different endpoints can be determined to pinpoint basal and specific toxicological cellular effects. Technological progress and increasingly refined protocols are extending the possibilities of cell-based in vitro assays in environmental toxicology and promoting their increasingly important role in biomonitoring.

An intelligent NIR-responsive chelate copper-based anticancer nanoplatform for synergistic tumor targeted chemo-phototherapy

The chelate copper-based anticancer drug bleomycin (BLM) is usually believed to bind metal ions especially Cu(ii) to generate the "activated BLM" for DNA cleavage. Herein, BLM and L-menthol (LM) co-loaded hollow mesoporous Cu_2-xS nanoparticles (HMCu_2-xS NPs) with surface folic acid (FA) modification were formulated to construct an intelligent NIR-responsive nanoplatform for synergistic tumor targeted chemo-phototherapy. With the tumor targeting ability of the folate receptor (FR)-positive, FA-HMCu_2-xS/BLM/LM could pinpoint tumor cells efficiently. Under NIR irradiation, the versatile HMCu_2-xS would be bound to exploit the merits of phototherapy (including PTT and PDT-like effects) for cancer treatment. Meanwhile, benefiting from the controllable "solid-liquid" (S-L) phase transition feature of LM as a gatekeeper, FA-HMCu_2-xS/BLM/LM offered a platform for simultaneous NIR-mediated temperature-responsive BLM and copper ion release, which further initiated the generation of the "activated BLM". As a matter of course, the remarkable synergistic combination of Cu-dependent chemo-phototherapy in vitro and in vivo by such a smart all-in-one drug delivery nanoplatform developed here provided information for advancing nanotherapy in biomedical fields.

Migration Rate Inhibition of Breast Cancer Cells Treated by Caffeic Acid and Caffeic Acid Phenethyl Ester: An In Vitro Comparison Study

One of the deadliest cancers among women is a breast cancer. Research has shown that two natural substances occurring in propolis, caffeic acid (CA) and caffeic acid phenethyl ester (CAPE), have significant anticancer effects. The purpose of our in vitro study was to compare cytotoxic activity and migration rate inhibition using CA and CAPE (doses of 50 and 100 µm) against triple-negative, MDA-MB-231 breast adenocarcinoma line cells, drawn from Caucasian women. Viability was measured by XTT-NR-SRB assay (Tetrazolium hydroxide-Neutral Red-Sulforhodamine B) for 24 h and 48 h periods. Cell migration for wound healing assay was taken for 0 h, 8 h, 16 h, and 24 h periods. CAPE displayed more than two times higher cytotoxicity against MDA-MB-231 cells. IC₅₀ values for the XTT assay were as follows: CA for 24 h and 48 h were 150.94 µM and 108.42 µM, respectively, while CAPE was 68.82 µM for 24 h and 55.79 µM for 48 h. For the NR assay: CA was 135.85 µM at 24 h and 103.23 µM at 48 h, while CAPE was 64.04 µM at 24 h and 53.25 µM at 48 h. For the SRB assay: CA at 24 h was 139.80 µM and at 48 h 103.98 µM, while CAPE was 66.86 µM at 24 h and 47.73 µM at 48 h. Both agents suspended the migration rate; however, CAPE displayed better activity. Notably, for the 100 µM CAPE dose, motility of the tested breast carcinoma cells was halted.

A tRNA fragment, tRF5-Glu, regulates BCAR3 expression and proliferation in ovarian cancer cells

Ovarian cancer is a complex disease marked by tumor heterogeneity, which contributes to difficulties in diagnosis and treatment. New molecular targets and better molecular profiles defining subsets of patients are needed. tRNA fragments (tRFs) offer a recently identified group of noncoding RNAs that are often as abundant as microRNAs in cancer cells. Initially their presence in deep sequencing data sets was attributed to the breakdown of mature tRNAs, however, it is now clear that they are actively generated and function in multiple regulatory events. One such tRF, a 5’ fragment of tRNA-Glu-CTC (tRF5-Glu), is processed from the mature tRNA-Glu and is shown in this study to be expressed in ovarian cancer cells. We confirmed that tRF5-Glu binds directly to a site in the 3’UTR of the Breast Cancer Anti-Estrogen Resistance 3 (BCAR3) mRNA thereby down regulating its expression. BCAR3 has not previously been studied in ovarian cancer cells and our studies demonstrate that inhibiting BCAR3 expression suppresses ovarian cancer cell proliferation. Furthermore, mimics of tRF5-Glu were found to inhibit proliferation of ovarian cancer cells. In summary, BCAR3 and tRF5-Glu contribute to the complex tumor heterogeneity of ovarian cancer cells and may provide new targets for therapeutic intervention.