Anticancer activity of a monobenzyltin complex C1 against MDA-MB-231 cells through induction of Apoptosis and inhibition of breast cancer stem cells

BMP Stimulation Differentially Affects Phosphorylation and Protein Stability of β-Catenin in Breast Cancer Cell Lines

Increased expression and nuclear translocation of β-CATENIN is frequently observed in breast cancer, and it correlates with poor prognosis. Current treatment strategies targeting β-CATENIN are not as efficient as desired. Therefore, detailed understanding of β-CATENIN regulation is crucial. Bone morphogenetic proteins (BMP) and Wingless/Integrated (WNT) pathway crosstalk is well-studied for many cancer types including colorectal cancer, whereas it is still poorly understood for breast cancer. Analysis of breast cancer patient data revealed that BMP2 and BMP6 were significantly downregulated in tumors. Since mutation frequency in genes enhancing β-CATENIN protein stability is relatively low in breast cancer, we aimed to investigate whether decreased BMP ligand expression could contribute to a high protein level of β-CATENIN in breast cancer cells. We demonstrated that downstream of BMP stimulation, SMAD4 is required to reduce β-CATENIN protein stability through the phosphorylation in MCF7 and T47D cells. Consequently, BMP stimulation reduces β-CATENIN levels and prevents its nuclear translocation and target gene expression in MCF7 cells. Conversely, BMP stimulation has no effect on β-CATENIN phosphorylation or stability in MDA-MB-231 and MDA-MB-468 cells. Likewise, SMAD4 modulation does not alter the response of those cells, indicating that SMAD4 alone is insufficient for BMP-induced β-CATENIN phosphorylation. While our data suggest that considering BMP activity may serve as a prognostic marker for understanding β-CATENIN accumulation risk, further investigation is needed to elucidate the differential responsiveness of breast cancer cell lines.

Synthesis, X-ray structure and anticancer activity evaluation of a binuclear La(III) complex with anthranilic acid

A binuclear La(III) complex {[La2(HA)4(H2O)4(C2H5OH)2Cl2]Cl4 (C1)} with 2-aminobenzoic acid (HA) was prepared from the ligand and heptahydrated lanthanum chloride. The complex was characterised by X-ray crystallography that revealed anti-prismatic geometry around both of the lanthanum. In the complex, the four 2-aminobenzoic acid ligands are zwitter ionic and the two lanthanum(III) ions net charge is only counterbalanced by chloride ions. The complex cytotoxicity was determined against human breast (MDA-MB-231), prostate (PC-3) and bladder (T-24) cancer cells. This complex afforded cytotoxicity towards the T-24 bladder cancer cells with an IC50 value of 383.5 µg/mL (319 µM). In contrary, activities by the lanthanum complex with IC50 values of 1124 µg/mL (934 µM) and 739 µg/mL (614 µM) were, respectively, shown against the MDA-MB-231 and PC-3 cancer cells. This means the complex is more cytotoxic against the T-24 cells, despite that its activity is less compared with activities shown by classical drugs.

6-Aryl-4-cycloamino-1,3,5-triazine-2-amines: synthesis, antileukemic activity, and 3D-QSAR modelling

Despite significant progress in immunotherapy and chimeric antigen receptor T cell therapy of leukemia, chemotherapy is the major treatment option for the disease. Therefore, the development of potent and safe drugs for standard and targeted chemotherapy of leukemia remains an important task for medicinal chemists. A library of 94 diverse 6-aryl-4-cycloamino-1,3,5-triazine-2-amines was prepared using a one-pot microwave-assisted protocol, which involves a three-component reaction of cyanoguanidine, aromatic aldehydes and cyclic amines, and subsequent dehydrogenative aromatization of the dihydrotriazine intermediates in the presence of alkali. The cytotoxic properties of prepared compounds were evaluated against the leukemic Jurkat T cell line and the selectivity of the 24 most active compounds was also assessed using a normal fibroblast MRC-5 cell line, indicating selective antiproliferative activity against leukemic cells. The structure-activity relationship was analysed, and the prepared 3D-QSAR model was found to predict the antileukemic activity of the compounds with reasonable accuracy. In the cell morphology study, both apoptosis and necrosis features were observed in Jurkat T cells after treatment with the most active compound.

Efficacy of metformin and electrical pulses in breast cancer MDA-MB-231 cells

Aim

Triple-negative breast cancer (TNBC) is a very aggressive subset of breast cancer, with limited treatment options, due to the lack of three commonly targeted receptors, which merits the need for novel treatments for TNBC. Towards this need, the use of metformin (Met), the most widely used type-2 diabetes drug worldwide, was explored as a repurposed anticancer agent. Cancer being a metabolic disease, the modulation of two crucial metabolites, glucose, and reactive oxygen species (ROS), is studied in MDA-MB-231 TNBC cells, using Met in the presence of electrical pulses (EP) to enhance the drug efficacy.

Methods

MDA-MB-231, human TNBC cells were treated with Met in the presence of EP, with various concentrations Met of 1 mmol/L, 2.5 mmol/L, 5 mmol/L, and 10 mmol/L. EP of 500 V/cm, 800 V/cm, and 1,000 V/cm (with a pulse width of 100 µs at 1 s intervals) were applied to TNBC and the impact of these two treatments was studied. Various assays, including cell viability, microscopic inspection, glucose, ROS, and wound healing assay, were performed to characterize the response of the cells to the combination treatment.

Results

Combining 1,000 V/cm with 5 mmol/L Met yielded cell viability as low as 42.6% at 24 h. The glucose level was reduced by 5.60-fold and the ROS levels were increased by 9.56-fold compared to the control, leading to apoptotic cell death.

Conclusions

The results indicate the enhanced anticancer effect of Met in the presence of electric pulses. The cell growth is inhibited by suppressing glucose levels and elevated ROS. This shows a synergistic interplay between electroporation, Met, glucose, and ROS metabolic alterations. The results show promises for combinational therapy in TNBC patients.

Molecular hybridization strategy for tuning bioactive peptide function

The physicochemical and structural properties of antimicrobial peptides (AMPs) determine their mechanism of action and biological function. However, the development of AMPs as therapeutic drugs has been traditionally limited by their toxicity for human cells. Tuning the physicochemical properties of such molecules may abolish toxicity and yield synthetic molecules displaying optimal safety profiles and enhanced antimicrobial activity. Here, natural peptides were modified to improve their activity by the hybridization of sequences from two different active peptide sequences. Hybrid AMPs (hAMPs) were generated by combining the amphipathic faces of the highly toxic peptide VmCT1, derived from scorpion venom, with parts of four other naturally occurring peptides having high antimicrobial activity and low toxicity against human cells. This strategy led to the design of seven synthetic bioactive variants, all of which preserved their structure and presented increased antimicrobial activity (3.1-128 μmol L-1). Five of the peptides (three being hAMPs) presented high antiplasmodial at 0.8 μmol L-1, and virtually no undesired toxic effects against red blood cells. In sum, we demonstrate that peptide hybridization is an effective strategy for redirecting biological activity to generate novel bioactive molecules with desired properties.

Synthesis, Solid State Structure, and Cytotoxic Activity of a Complex Dimer of Yttrium with Anthranilic Acid against Cancer Cells

This paper presents the synthesis and isolation of a new binuclear complex of yttrium with anthranilic acid (HA). The complex [Y2(HA)6(H2O)4] Cl6.2C2H5OH (C1) was obtained as single crystals that its X-ray analysis revealed its triclinic P-1 space group in addition to anti-prismatic geometry around each of the yttrium ions. In the complex, the anthranilic acid ligands are bidentate, zwitter ionic and neutral, and the yttrium ions' charge is only compensated by six chloride ions. The cytotoxicity of this complex against human breast cancer MDA-MB-231 cells, prostate cancer PC-3 cells, and bladder cancer T-24 cells was evaluated. This yttrium complex displayed more cytotoxic activity against the bladder cancer cells with an IC50 value of 307.7 μg/ml (223 μM). On the other hand, the activities of complex C1 against the MDA-MB-231 and PC-3 cells were less significant respectively with IC50 values of 1097 μg/ml (796 μM) and 921 μg/ml (669 μM).

Thallium-induced DNA damage, genetic, and epigenetic alterations

Thallium (Tl) is a toxic heavy metal responsible for noxious effects in living organisms. As a pollutant, Tl can be found in the environment at high concentrations, especially in industrial areas. Systemic toxicity induced by this toxic metal can affect cell metabolism, including redox alterations, mitochondrial dysfunction, and activation of apoptotic signaling pathways. Recent focus on Tl toxicity has been devoted to the characterization of its effects at the nuclear level, with emphasis on DNA, which, in turn, may be responsible for cytogenetic damage, mutations, and epigenetic changes. In this work, we review and discuss past and recent evidence on the toxic effects of Tl at the systemic level and its effects on DNA. We also address Tl's role in cancer and its control.

Nimbin analog N2 alleviates high testosterone induced oxidative stress in CHO cells and alters the expression of Tox3 and Dennd1a signal transduction pathway involved in the PCOS zebrafish

Polycystic ovarian syndrome (PCOS) is a hormonal disorder that causes enlargement of ovaries and follicular maturation arrest, which lacks efficient treatment. N2, a semi-natural triterpenoid from the neem family, was already reported to have antioxidant and antiinflammatory properties in our previous report. This study investigated the anti-androgenic property of N2 on testosterone-induced oxidative stress in Chinese Hamster Ovarian cells (CHO) and PCOS zebrafish model. The testosterone exposure disrupted the antioxidant enzymes and ROS level and enhanced the apoptosis in both CHO cells and PCOS zebrafish. However, N2 significantly protected the CHO cells from ROS and apoptosis. N2 improved the Gonado somatic index (GSI) and upregulated the expression of the SOD enzyme in zebrafish ovaries. Moreover, the testosterone-induced follicular maturation arrest was normalized by N2 treatment in histopathology studies. In addition, the gene expression studies of Tox3 and Denndla in zebrafish demonstrated that N2 could impair PCOS condition. Furthermore, to confirm the N2 activity, the in-silico studies were performed against PCOS susceptible genes Tox3 and Dennd1a using molecular docking and molecular dynamic simulations. The results suggested that N2 alleviated the oxidative stress and apoptosis in-vitro and in-vivo and altered the expression of PCOS key genes.

Cytotoxic effects of halogenated tin phosphinoyldithioformate complexes against several cancer cell lines

Organotin complexes are studied as promising alternatives to the anticancer drug cisplatin. We report two monoorganotin(IV) complexes based on a dibenzyl phosphinoyldithioformate (H-DBPTF) ligand, containing either bromide (Sn-DBPTF-1) or chloride (Sn-DBPTF-2) anions. The complexes were characterized by standard analytical techniques and the structural details of these complexes were elucidated by single crystal X-ray diffraction. Sn-DBPTF-1 was cytotoxic at IC50 <10 μg mL-1 against cancer cell lines A549 (lung cancer), Aspc-1 (pancreatic cancer), OVCAR-3 (ovarian cancer), T-47D (breast cancer) and HCT116 (colon cancer), and breast epithelial stem cell line D492. The non-tumorigenic breast epithelial cell line MCF-10 was less sensitive at IC50 = 22 μg mL-1. Sn-DBPTF-2 had limited cytotoxic effect at IC50 13-37 μg mL-1. Sn-DBPTF-1 induced apoptosis and double-strand DNA breaks. Cell cycle arrest in G2 occurred in HCT116 and accumulation in G1 in Aspc-1. The results indicate that the basic effect of Sn-DBPTF-1 is to induce DNA damage, leading to apoptosis and cell cycle arrest depending on the cell line.

2-Dimensional in vitro culture assessment of ovarian cancer cell line using cost effective silver nanoparticles from Macrotyloma uniflorum seed extracts

Our research focused on generating AgNPs using Macrotyloma uniflorum (MU) seed extracts and studied their efficacy in combating tumor growth using the 2-Dimensional method for ovarian cancer cell line-PA-1. Characterization studies including a UV-visible spectrophotometer confirmed the surface plasmon resonance peak of 436 nm. Particle size determination data validated the nanoparticle diameter of 91.8 nm. Synthesized AgNPs possess a negative charge of -28.0 mV, which was confirmed through the zeta potential study. Structural characterization studies including XRD determined the crystal phase of AgNPs at four distant peaks at 2θ (38.17, 44.36, 64.52, and 77.46) and were assigned to 111, 200, 220, and 311 planes of the FCC. FTIR studies have confirmed the presence of O-H, N-H, C=O, ethers, C-Br, and C-I groups in AgNPs respectively. DPPH study has confirmed the presence of free radicles and we observed that at 500 μg/ml concentration, 76.08% of free radicles were formed which shows their efficiency. MTT assay shows the efficacy of MU-AgNPs in reducing the cell viability. At lower concentrations of MU-AgNP, 66% viability was observed and 9% of viability was observed at higher dose. ROS production (21%) was observed using MU-AgNPs with respect to 0.45% in controls, which affirms the capacity to induce DNA damage via apoptosis. Standard drug camptothecin generated 26% of ROS production which confirms higher potential of AgNPs in inducing DNA damage in tumor cells without causing lethality to the healthy cells. Further, the Fluorescence-activated cell sorting (FACS) study using a standard Caspase-3 marker confirms the generation of apoptotic bodies using two different concentrations of MU-AgNPs. At 40 μg, 64% of apoptotic cell death was observed, whereas, using 20 μg, 23% of apoptosis was recorded via fluorescent intensity. Propidium iodide-based Cell cycle study has shown a significant decrease in G0/G1 phase compared to control (88.8%), which further confirmed the apoptotic induction. Matrix metalloproteinases (MMP) studies using JC-1 dye, showed a significant increase in green fluorescence owing to lowered membrane potential, thus ensuring the breakdown of mitochondrial potential compared to untreated and standard drugs. With the obtained results, we are concluding that MU-AgNPs has a tremendous capacity to suppress the ovarian cancer cell proliferation in vitro by inducing DNA damage and apoptosis.

Exosomal-microRNA transcriptome profiling of Parental and CSC-like MDA-MB-231 cells in response to cisplatin treatment

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype with higher risk of metastasis and cancer reoccurrence. Cisplatin is one of the potential anticancer drugs for treating TNBC, where its effectiveness remains challenged by frequent occurrence of cisplatin resistance. Since acquirement of drug resistance often being associated with presence of cancer stem cells (CSCs), investigation has been conducted, suggesting CSC-like subpopulation to be more resistant to cisplatin than their parental counterpart. On the other hand, plethora evidences showed the transmission of exosomal-miRNAs are capable of promoting drug resistance in breast cancers. In this study, we aim to elucidate the differential expression of exosomal-microRNAs profile and reveal the potential target genes in correlation to cisplatin resistance associated with CSC-like subpopulation by using TNBC cell line (MDA-MB-231). Utilizing next generation sequencing and Nanostring techniques, cisplatin-induced dysregulation of exosomal-miRNAs were evaluated in maximal for CSC-like subpopulation as compared to parental cells. Intriguingly, more oncogenic exosomal-miRNAs profile was detected from treated CSC-like subpopulation, which may correlate to enhancement of drug resistance and maintenance of CSCs. In treated CSC-like subpopulation, unique clusters of exosomal-miRNAs namely miR-221-3p, miR-196a-5p, miR-17-5p and miR-126-3p were predicted to target on six genes (ATXN1, LATS1, GSK3β, ITGA6, JAG1 and MYC), aligned with previous finding which demonstrated dysregulation of these genes in treated CSC-like subpopulation. Our results highlight the potential correlation of exosomal-miRNAs and their target genes as well as novel perspectives of the corresponding pathways that may be essential to contribute to the attenuated cytotoxicity of cisplatin in CSC-like subpopulation.

Mineral requirements for mitochondrial function: A connection to redox balance and cellular differentiation

Professor Bruce Ames demonstrated that nutritional recommendations should be adjusted in order to 'tune-up' metabolism and reduce mitochondria decay, a hallmark of aging and many disease processes. A major subset of tunable nutrients are the minerals, which despite being integral to every aspect of metabolism are often deficient in the typical Western diet. Mitochondria are particularly rich in minerals, where they function as essential cofactors for mitochondrial physiology and overall cellular health. Yet substantial knowledge gaps remain in our understanding of the form and function of these minerals needed for metabolic harmony. Some of the minerals have known activities in the mitochondria but with incomplete regulatory detail, whereas other minerals have no established mitochondrial function at all. A comprehensive metallome of the mitochondria is needed to fully understand the patterns and relationships of minerals within metabolic processes and cellular development. This brief overview serves to highlight the current progress towards understanding mineral homeostasis in the mitochondria and to encourage more research activity in key areas. Future work may likely reveal that adjusting the amounts of specific nutritional minerals has longevity benefits for human health.

HSP70s in Breast Cancer: Promoters of Tumorigenesis and Potential Targets/Tools for Therapy

The high frequency of breast cancer worldwide and the high mortality among women with this malignancy are a serious challenge for modern medicine. A deeper understanding of the mechanisms of carcinogenesis and emergence of metastatic, therapy-resistant breast cancers would help development of novel approaches to better treatment of this disease. The review is dedicated to the role of members of the heat shock protein 70 subfamily (HSP70s or HSPA), mainly inducible HSP70, glucose-regulated protein 78 (GRP78 or HSPA5) and GRP75 (HSPA9 or mortalin), in the development and pathogenesis of breast cancer. Various HSP70-mediated cellular mechanisms and pathways which contribute to the oncogenic transformation of mammary gland epithelium are reviewed, as well as their role in the development of human breast carcinomas with invasive, metastatic traits along with the resistance to host immunity and conventional therapeutics. Additionally, intracellular and cell surface HSP70s are considered as potential targets for therapy or sensitization of breast cancer. We also discuss a clinical implication of Hsp70s and approaches to targeting breast cancer with gene vectors or nanoparticles downregulating HSP70s, natural or synthetic (small molecule) inhibitors of HSP70s, HSP70-binding antibodies, HSP70-derived peptides, and HSP70-based vaccines.

Metal complexes against breast cancer stem cells

With the highest incidence, breast cancer is the leading cause of cancer deaths among women in the world. Tumor metastasis is the major contributor of high mortality in breast cancer, and the existence of cancer stem cells (CSCs) has been proven to be the cause of tumor metastasis. CSCs are a small proportion of tumor cells, and they are associated with self-renewal and tumorigenic potential. Given the significance of CSCs in tumor initiation, expansion, relapse, resistance, and metastasis, studies should investigate and discover effective anticancer agents that can not only inhibit the proliferation of differentiated tumor cells but also reduce the tumorigenic capability of CSCs. Thus, new therapies must be discovered to treat and prevent this severely hazardous disease of human beings. The success of platinum complexes in cancer treatment has laid the basic foundation for the utilization of metal complexes in the treatment of malignant cancers, in particular the highly aggressive triple-negative breast cancer. Importantly, metal complexes currently have diverse and versatile competences in the therapeutic targeting of CSCs. The anti-CSC properties provide a strong impetus for the development of novel metal-based compounds for the targeting of CSCs and treatment of chemotherapy-resistant and relapsed tumors. In this review, we provide the latest advances in metal complexes including platinum, ruthenium, osmium, iridium, manganese, cobalt, nickel, copper, zinc, palladium, and tin complexes against breast CSCs obtained over the past decade, with pertinent literature including those published until 2021.

Novel Tl(III) complexes containing pyridine-2,6-dicarboxylate derivatives with selective anticancer activity through inducing mitochondria-mediated apoptosis in A375 cells

Three novel Tl(III) complexes (C1), (C2) and (C3) were synthesized using the one-pot reactions of pyridine dicarboxylic acid derivatives, 2-aminobenzimidazole and/or 4-aminopyridine, and also thallium(III) nitrate trihydrate metal salt. The structure of all three complexes was determined by the single-crystal X-ray diffraction. C1 and C2 were realized to be isostructural with disordered square anti-prismatic geometry and for C3 arrangement of the distorted tricapped triangular prism was proposed. Cyclic voltammetry measurements on the complexes exhibited that formal potential values are more positive for C1 (E⁰' 0.109 V) and C3 (E⁰' 0.244 V) compared to C2 (E⁰' -0.051 V), versus Ag/AgCl under argon. Moreover, cytotoxicity of the compounds was evaluated in vitro against two cancer cell lines including a human melanoma (A375), a human colon adenocarcinoma (HT29), and also one normal cell human foreskin fibroblast (HFF). The selective and potent cytotoxicity effect was exhibited by C1 and C3 on cancer cell lines. The apoptosis through a caspase-dependent mitochondrion pathway was confirmed by ROS production, MMP reduction, p53 activation, Bax up-regulation, and Bcl-2 down-regulation, cytochrome c release, procaspase-9, and 3 expression, for A375 cells treated to C1 and C3. According to similar cellular uptake of the complexes in A375 cell line, the generation of ROS was considered as an effective agent to justify the inhibition effect C1 and C3 on mentioned cells. Furthermore, arresting the cell cycle in the G2-M phase and inducing apoptosis were indicated by these two complexes.

Cytotoxic and apoptosis-inducing effects of novel 8-amido isocoumarin derivatives against breast cancer cells

Isocoumarin is a lactone, a type of natural organic compound that is used as synthetic intermediates of several natural products and pharmaceutical compounds explored for their potential therapeutic applications like antifungal, antimicrobial, anti-inflammatory, and anticancer activities. In our previous work, we were the first group to report the use of amide C-N bond of isatins as the oxidizing directing group for the synthesis of 8-amido isocoumarin derivatives. Whereas in our present work, we have screened the cytotoxic effects of novel 8-amido isocoumarin derivatives (S1-S10) in human breast cancer MCF-7 and MDA-MB-231 cells. Our novel results revealed that N-(3-(4-methoxyphenyl)-1-oxo-4-(4-propylphenyl)-1H-isochromen-8yl)acetamide (S1) and N-(4-(3,5-difluorophenyl)-1-oxo-3-(p-tolyl)-1H-isochromen-8-yl) acetamide (S2) are the two potent compounds among the rest synthesized isocoumarin derivatives that are cytotoxic against MCF-7 and MDA-MB-231 cells, whereas less toxic to the non-tumorigenic IOSE-364 cells. Flow cytometry studies have confirmed the induction of apoptotic effects of compounds by Annexin V/PI double staining. We also observed the cytotoxic effects of S1 and S2, as evaluated by DAPI-PI immunostaining and H&E staining. The morphological alterations consistent with apoptotic blebs were observed in both cancer cells treated with compounds assessed by scanning electron microscopy. Overall, this present study strongly demonstrates that 8-amido isocoumarin derivatives have potent cytotoxic and apoptotic effects in breast cancer cells.

Biogenesis of silver nanoparticles to treat cancer, diabetes, and microbial infections: a mechanistic overview

Green synthesis of silver nanoparticles (SNPs) by harnessing the natural abilities of plant secondary metabolites has advantages over routine physical and chemical synthetic approaches due to their one-step experimental setup to reduce and stabilize the bulk silver into SNPs, biocompatible nature, and therapeutic significance. The unique size, shape, and biochemical functional corona of SNPs embellish them with the potential to perform therapeutic actions by adopting various mechanistic approaches including but not limited to the disruption of the electron transport chain, mitochondrial damage, DNA fragmentation, inhibition of ATP synthase activity, disorganization of the cell membrane, suspension of cellular signaling pathways, induction of apoptosis, and inhibition of enzymes activity. This review elaborates the biogenic synthesis of SNPs in redox chemical reactions by using plant secondary metabolites found in plant extracts. In addition, it explains the synergistic influence of physicochemical reaction parameters such as the temperature, pH, the concentration of the AgNO₃, and the ratio of reactants to affect the reaction kinetics, molecular mechanics, enzymatic catalysis, and protein conformations that aid to affect the size, shape, and potential biochemical corona of nanoparticles. This review also provides up-to-date information on the mechanistic actions that embellish the plant-based SNPs, an anticancer, cytotoxic, antidiabetic, antimicrobial, and antioxidant potential. The mechanistic understanding of the therapeutic actions of SNPs will help in precision medicine to develop customized treatment and healthcare approaches for the welfare of the human population. KEY POINTS: • Significance of the biogenic nanoparticles • Biomedical application potential of the plant-based silver nanoparticles • Mechanism of the anticancer, antidiabetic, and antimicrobial actions of the plant-based silver nanoparticles.

Net charge tuning modulates the antiplasmodial and anticancer properties of peptides derived from scorpion venom

VmCT1, a linear helical antimicrobial peptide isolated from the venom of the scorpion Vaejovis mexicanus, displays broad spectrum antimicrobial activity against bacteria, fungi, and protozoa. Analogs derived from this peptide containing single Arg-substitutions have been shown to increase antimicrobial and antiparasitic activities against Trypanossoma cruzi. Here, we tested these analogs against malaria, an infectious disease caused by Plasmodium protozoa, and assessed their antitumoral properties. Specifically, we tested VmCT1 synthetic variants [Arg]³ -VmCT1-NH₂ , [Arg]⁷ -VmCT1-NH₂ , and [Arg]¹¹ -VmCT1-NH₂ , against Plasmodium gallinaceum sporozoites and MCF-7 mammary cancer cells. Our screen identified peptides [Arg]³ -VmCT1-NH₂ and [Arg]⁷ -VmCT1-NH₂ as potent antiplasmodial agents (IC₅₀ of 0.57 and 0.51 μmol L^-1 , respectively), whereas [Arg]¹¹ -VmCT1-NH₂ did not show activity against P. gallinaceum sporozoites. Interestingly, all peptides presented activity against MCF-7 and displayed lower cytotoxicity toward healthy cells. We demonstrate that increasing the net positive charge of VmCT1, through arginine substitutions, modulates the biological properties of this peptide family yielding novel antiplasmodial and antitumoral molecules.

Prodigiosin/PU-H71 as a novel potential combined therapy for triple negative breast cancer (TNBC): preclinical insights

Prodigiosin, a secondary metabolite red pigment produced by Serratia marcescens, has an interesting apoptotic efficacy against cancer cell lines with low or no toxicity on normal cells. HSP90α is known as a crucial and multimodal target in the treatment of TNBC. Our research attempts to assess the therapeutic potential of prodigiosin/PU-H71 combination on MDA-MB-231 cell line. The transcription and protein expression levels of different signalling pathways were assessed. Treatment of TNBC cells with both drugs resulted in a decrease of the number of adherent cells with apoptotic effects. Prodigiosin/PU-H71 combination increased the levels of caspases 3,8 and 9 and decreased the levels of mTOR expression. Additionally, there was a remarkable decrease of HSP90α transcription and expression levels upon treatment with combined therapy. Also, EGFR and VEGF expression levels decreased. This is the first study to show that prodigiosin/PU-H71 combination had potent cytotoxicity on MDA-MB-231 cells; proving to play a paramount role in interfering with key signalling pathways in TNBC. Interestingly, prodigiosin might be a potential anticancer agent to increase the sensitivity of TNBC cells to apoptosis. This study provides a new basis for upcoming studies to overcome drug resistance in TNBC cells.

Phytosynthesis of colloidal nanosilver from Mentha longifolia and Mentha arvensis: Comparative morphological and optical characterization

The present study involves an ecofriendly strategy for the reduction of bulk silver into its nanoforms by using the aqueous extracts of Mentha longifolia leaves (MLL), M. longifolia branches (MLB), and Mentha arvensis (MA). Synthesis of silver nanoparticles (AgNPs) was confirmed initially by observing a change in the color of the reaction mixture followed by measuring the absorbance, and a characteristic surface plasmon resonance band was observed between 400 and 500 nm of the λ of light. Morphological and optical characterization techniques of AgNPs were performed by using UV-visible spectrophotometer, scanning electron microscopy, atomic force microscopy, energy-dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS) analysis. It was confirmed that the phytosynthesized nanoparticles are anisotropic and nearly spherical having a size smaller than 100 nm while some cubical and prismatic nanostructures were also observed. The average size of a single nanoparticle measured by DLS analysis was reported 10.50 nm, 15.55 nm, and 20.46 nm biofabricated by using MLB, MLL, and MA extract, respectively. The EDX analysis reported the presence of elemental Ag while elemental O was also observed in MLL and MLB AgNPs. The results from these experiments endorse the potential of reported plant species to phytosynthesize AgNPs. The future applications of this work involve the utilization of AgNPs for multiple biological applications.

Heterometrus Spinifer: An Untapped Source of Anti-Tumor Molecules

Despite intensive research, cancer incidence and mortality continue to rise. Consequently, the necessity to develop effective anti-cancer therapy is apparent. We have recently shown that the gut bacteria of animals living in polluted environments, such as crocodiles, are a potential source of novel anti-tumor molecules. To extend this work to other resilient species, we investigated the anti-tumor effects of gut bacteria of Heterometrus spinifer (a scorpion). Bacteria from the feces and gut were isolated, identified and evaluated for their anti-tumor effects. Bacterial-conditioned media was prepared in Roswell Park Memorial Institute (RPMI) 1640 media, and cytotoxicity and growth inhibitory properties were examined against cervical (HeLa) cancer cells. Liquid chromatography–mass spectrometry (LC-MS) was conducted to establish the identity of the molecules. Eighteen bacteria species from the gut (HSG01-18) and ten bacteria species from feces (HSF01-10) were tested for anti-tumor effects. Bacterial-conditioned media from scorpion gut and feces exhibited significant growth inhibitory effects against HeLa cells of 66.9% and 83.8%, respectively. Microscopic analysis of cancer cells treated with conditioned media HSG12 and HSG16 revealed apoptosis-like effects. HSG12 was identified as Pseudomonas aeruginosa and HSG16 was identified as Bacillus subtilis. Both conditioned media exhibited 100% growth inhibitory effects versus a selection of cancer cells, comprising cervical, breast and prostate cancer cells. LC–MS indicated the presence of 72 and 38 compounds, detected from HSG12 and HSG16, respectively. Out of these compounds, 47 were successfully identified while the remainder were unidentified and are possibly novel. This study suggests that the fecal and gut microbiota of scorpions might possess molecules with anti-cancer properties, however, further intensive research is needed to assess these expectations.

Synergistic Effects of Physicochemical Parameters on Bio-Fabrication of Mint Silver Nanoparticles: Structural Evaluation and Action Against HCT116 Colon Cancer Cells

Background

Physicochemical parameters such as temperature, pH, the concentration of the AgNO₃ and ratio of reactants act synergistically to influence the reaction kinetics, molecular mechanics, enzymatic catalysis and protein conformations that aid to affect the size, shape and biochemical corona of nanoparticles. The present study was performed to investigate the influence of reaction parameters on the bio-fabrication of silver nanoparticles (AgNPs) by using Mentha arvensis and to determine their potential to control the proliferation of colon cancer cells'.

Methods

Plant-mediated method was used for the bio-fabrication and stabilization of AgNPs. Reaction parameters were arranged, and surface plasmon resonance (SPR) bands of AgNPs were collected by using a UV-Visible spectrophotometer. NPs were characterized structurally and optically by using SEM, AFM, EDX and DLS techniques. AgNPs and plant aqueous extract were tested against HCT116 colon cancer cells by using SRB assay, Annexin V assay and cell cycle analysis.

Results

Spectrophotometric comparison of various reaction conditions manifested that 5 mM of AgNO₃, 60 °C in an acidic pH and a mixing ratio of 1:9 of plant extract and AgNO₃, respectively, are the optimized conditions for AgNP synthesis. Structural evaluation by SEM, AFM and particle size analysis confirmed that the NPs are <100 nm and are anisotropic, spherical, triangular and moderately dispersed in the colloidal mixture. SRB assay expressed biomass-stabilized AgNPs as effective cytotoxic particles against HCT116 colon cancer cells, and the IC₅₀ was measured at 1.7 µg/mL. Annexin V apoptosis assay further confirmed that the AgNPs induce apoptosis in a dose-dependent manner. Experimental evidence manifested that the AgNPs arrest cell cycle and expressed entrapment of a greater number of cells in the Sub-G1 phase, further verifying the anticancer abilities of AgNPs.

Conclusion

These findings explain the synergistic effects of physicochemical parameters to optimize the phytosynthesis of biocompatible AgNPs to overcome the limitations of conventional chemotherapeutic treatments of colon cancer cells.

AOC1 Contributes to Tumor Progression by Promoting the AKT and EMT Pathways in Gastric Cancer

Background

AOC1 is a copper-containing amine oxidase that is responsible for catalyzing the deamination of polyamines, which produces reactive oxygen species. Previous studies have demonstrated that polyamines are involved in the regulation of proliferation, migration, and apoptosis of cells. However, very little is known about the functions and regulatory mechanisms of AOC1 in tumors.

Methods

Based on GEPIA data, we found that AOC1 was significantly upregulated in human gastric cancer tissues. We knocked down AOC1 in human AGS and MKN45 cells using siRNA transfection, then utilized qRT-PCR assay and Western blot to verify the effectiveness of AOC1 knockdown in gastric cancer cells.

Results

Function analysis demonstrated that knockdown of AOC1 inhibited the proliferation, invasion, and migration of human gastric cancer cells. Flow cytometry detection suggested that AOC1 knockdown induced apoptosis in human gastric cancer cells. Mechanism investigation suggested that AOC1 knockdown increased the ratio of Bax/Bcl2 and induced activation of the caspase cascade. Furthermore, the AKT signaling pathway was inactivated when AOC1 was silenced, including downregulated phosphorylation level of AKT and expression of downstream effectors, Cyclin D1, and p70S6K. Finally, we found that knockdown of AOC1 inhibited the epithelial–mesenchymal transition (EMT) in human gastric cancer by increasing the expression of epithelial markers E-cadherin, as well as decreasing mesenchymal marker N-cadherin, SNAIL and Slug.

Conclusion

Our study suggests that AOC1 functions as an oncogene in human gastric cancer by activating the AKT signaling pathway and EMT process and maybe a target of 6-mercaptopurine, which provides new insight in the clinical use of AOC1 in gastric cancer therapy.

Bioactive Immunomodulatory Compounds: A Novel Combinatorial Strategy for Integrated Medicine in Oncology? BAIC Exposure in Cancer Cells

The Standardized Cultured Extract of Lentinula edodes Mycelia (also known as Active Hexose Correlated Compound, AHCC) and Wasabia japonica (Wasabi) are natural nutritional supplements known for their immunomodulatory and anticancer potential. The aim of this study was to evaluate the combinatorial effect of the bioactive immunomodulatory compound (BAIC), obtained by combining Wasabi and AHCC, on human breast (MCF-7) and pancreatic (Panc02) adenocarcinoma cell lines. Data obtained revealed that BAIC determines a striking decline in cancer cell growth at minimal concentrations compared with the use of Wasabi and AHCC as single agents. A significant increase in the G₀/G₁ subpopulation together with a marked augmentation in the percentage of apoptotic cells was demonstrated by flow cytometry, together with a significant upregulation in the expression of genes associated to the apoptotic cascade in both cell lines. The inhibitory role BAIC plays in mammospheres formation from MCF-7-derived cancer stem cells was shown with a marked reduction in size and number. Interestingly, when BAIC was exposed to monocytic cells, no cytotoxic effects were observed. A monocytes-to-macrophages differentiation was rather observed with the concomitant acquisition of an anti-inflammatory phenotype. Taken together, our findings suggest that BAIC could be used as a potential integration of standard chemotherapy treatments because of the improved inhibitory activity on cancer cell proliferation and reduced potential adverse effects.

Lycium barbarum polysaccharides exert an antioxidative effect on rat chondrocytes by activating the nuclear factor (erythroid-derived 2)-like 2 signaling pathway

INTRODUCTION

Oxidative stress is the main cause of osteoarthritis (OA). Lycium barbarum polysaccharides (LBP) have antioxidant properties. Thus, the potential effect of LBP on H₂O₂-stimulated chondrocytes was examined.

MATERIAL AND METHODS

The cell viability was detected by CCK-8. The reactive oxygen species (ROS) production and apoptosis rates were determined by flow cytometric analysis. The DNA damage was detected by comet assay. Real-time polymerase chain reaction (qPCR) and Western blot assays were performed to examine the expression of histone 2A family member X (γH2AX), checkpoint kinase 1 (Chk1), poly ADP-ribose polymerase (PARP), cysteinyl aspartate specific proteinase (caspase)-3/8/9, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its antioxidant-response element (ARE) dependent factors including heme oxygenase-1 (HO-1) and quinine oxidoreductase-1 (NQO-1).

RESULTS

Compared to the H₂O₂ group, LBP inhibited the ROS production and DNA damage caused by H₂O₂ (p < 0.05), respectively. LBP inhibited the mRNA and protein expressions of γH2AX and Chk1 (p < 0.05). Meanwhile, LBP significantly decreased apoptosis (p < 0.05). And LBP inhibited the expression levels of PARP and Caspase-3/8/9 (p < 0.05). Moreover, LBP increased the expression of Nrf2, HO-1and NQO-1 (p < 0.05). Furthermore, the depletion of Nrf2 that mediated by RNA interference reversed the apoptosis and DNA damage inhibition effect of LBP (p < 0.05).

CONCLUSIONS

LBP protected chondrocytes through inhibiting DNA damage and apoptosis caused by H₂O₂, in which the Nrf2/ARE signaling pathway played a positive role. It provided an inspiration for clinical application - developing LBP as a therapeutic agent and Nrf2 as a promising candidate.

Heat shock protein 70 dampens the inflammatory response of human PDL cells to mechanical loading in vitro

BACKGROUND AND OBJECTIVE

Previously, we demonstrated an inflammatory response of human PDL (hPDL) cells to mechanical loading. The cellular reaction was dampened by heat pre-treatment suggesting a protective role for heat shock proteins (HSP) during stress-induced ischemia. Here we explored if HSP70, which has already been documented in the pressure zone of tooth movement, might be regulatorily involved in the attenuation of the inflammatory response.

MATERIALS AND METHODS

Fifth passage hPDL cells were mechanically loaded in the presence of the HSP70 inhibitor VER155008. Cell morphology, HSP70 expression, viability, IL-6 and IL-8 expression were determined by means of microscopy, realtime-PCR and ELISA. The conditioned medium of mechanically loaded and pre-treated hPDL cells was used to culture monocytes to identify a potential impact on adhesion and osteoclastic differentiation capacity.

RESULTS

Mechanical cell stress resulted in a significant increase of pro-inflammatory parameters. HSP70 inhibition led to a further enhancement of cytokine expression. The conditioned medium of mechanically loaded hPDL cells significantly increased monocyte adhesion and differentiation along the osteoclastic pathway. VER155008 pronounced this effect significantly.

CONCLUSION

The results indicate a regulatory role for HSP70 in the control of the inflammatory hPDL cell response to mechanical loading and identify HSP70 as a target in the attempt to attenuate tissue damage during orthodontic tooth movement. Furthermore, the present findings point to the risk of increased periodontal destruction when medication targeting HSP70 is applied for severe medical conditions during orthodontic tooth movement.

Theaflavins prevent cartilage degeneration via AKT/FOXO3 signaling in vitro

Theaflavins (TFs) are the main bioactive polyphenols in tea and contribute to protection against oxidative stress. Excessive reactive oxygen species (ROS) accumulation can lead to the disruption of cartilage homeostasis. The present study examined the potential effects of TFs on H₂O₂-induced cartilage degeneration in vitro. Cell Counting kit (CCK-8) was used to determine cell viability, and flow cytometric analysis was used to detect ROS, apoptosis and DNA damage. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression levels of target factors. The present study revealed that TFs effectively reduced the expression of catabolic factors, including matrix metalloproteinase-13, interleukin-1 and cartilage glycoprotein 39. TFs inhibited ROS generation in cartilage degeneration, and suppressed apoptosis and DNA damage caused by oxidative stress. TFs also downregulated the expression levels of cleaved caspase-3 and B-cell lymphoma 2-associated X protein, and the DNA damage-related genes, ATR serine/threonine kinase and ATM serine/threonine kinase. Furthermore, TFs enhanced the activity of glutathione peroxidase 1 and catalase, but reduced the expression levels of phosphorylated (p)-AKT serine/threonine kinase (AKT) and p-Forkhead box O3 (FOXO3)a. Conversely, the effects of TFs on apoptosis and DNA damage were reversed by persistent activation of AKT. In conclusion, TFs prevented cartilage degeneration via AKT/FOXO3 signaling in vitro. The present study suggested that TFs may be a potential candidate drug for the prevention of cartilage degeneration.

Role of HSP70 protein in human periodontal ligament cell function and physiology

OBJECTIVE

Heat pre-treatment of mechanically loaded human periodontal ligament cells (hPDL) dampens the inflammatory cellular response, as evidenced by a reduced expression of pro-inflammatory cytokines, inhibition of monocyte adhesion and osteoclastic differentiation. These findings imply heat shock proteins (HSP) as cell protective molecules acting in the PDL that are up-regulated upon ischemia caused by mechanical loading. HSP70 and its inhibition by VER155008 as the active agent in several pharmaceuticals are established targets and strategies, respectively, in the treatment of neoproliferative diseases. However, the effect of both players on periodontal remodeling in unknown. Therefore, we analyzed the role of HSP70 and its frequently used inhibitor VER155008 in the regulation of physiological hPDL cell functions and immune cell interaction.

MATERIALS AND METHODS

Fifth passage hPDL cells were cultured in the presence of 25μm HSP70 inactivating agent VER155008. At harvest, HSP70 expression, cell proliferation, and parameters of cell interaction, colony formation and wound healing were analyzed by means of real-time PCR, immunohistochemistry, Western blot, biochemical MTS assay, microscopy, and functional assays for monocyte adhesion and differentiation.

RESULTS

Basal HSP70 expression and hPDL cell morphology were not affected by HSP70 inhibitor VER155008. In contrast, cell proliferation, tissue defect healing, and colony formation were reduced significantly following HSP70 inhibition, whereas apoptosis and necrosis, monocyte adhesion and osteoclastic differentiation were markedly increased.

CONCLUSIONS

The present data indicate a regulatory role for HSP70 protein in hPDL cell biology.

CLINICAL RELEVANCE

These findings identify HSP70 as a promising target in the attempt to modify periodontal remodeling and point to potential periodontal side effects of HSP70 pharmaceutical usage.

Oxidative DNA damage induced by ROS-modulating agents with the ability to target DNA: A comparison of the biological characteristics of citrus pectin and apple pectin

DNA targeting anticancer agents have been very successful in clinic, especially, when used in combinatorial therapy. But unfortunately, they often exhibit high levels of toxicity towards normal cells. Hence, much effort has been put into finding agents with more selectivity, and less toxicity. Pectins are natural polysaccharides, and beneficial nutritional fibers that have attracted attentions due to their antitumor properties. However, their molecular targets, and mechanism of action are widely unknown. Here, we have reported that citrus pectin (CP) and apple pectin (AP) selectively suppress viability in MDA-MB-231, MCF-7 and T47D human Breast cancer cells, while non-toxic to L929 normal cells. Upon CP, and AP treatments, cancer cells’ ROS content increased rapidly, and led to the collapse of the mitochondrial transmembrane potential which functions upstream of the caspase-dependent apoptosis. CP and AP treated cancer cells were also arrested at the S and G1 or G2/M phases of the cell cycle, respectively. Furthermore, mRNA expression of Galectin-3 (a multi-functional lectin involved in cell adhesion, cell cycle, and apoptosis) reduced in both CP and AP treated cells. Growth inhibition of MDA-MB-231 cells by CP, and AP was concomitant with DNA damage (oxidation, and strand breaks). In this context, in an effort to clarify the mechanism of action, we showed that CP, and AP are able to interact with DNA. The strength and mode of DNA binding were established by spectroscopy techniques. We demonstrated that CP, and AP bind to dsDNA by intercalation, and groove binding/partial intercalation, respectively. In conclusion, our findings suggest that CP, and AP induce apoptosis in MDA-MB-231 cells by increasing the release of ROS, which may be related to the mitochondrial apoptosis pathway, and direct interactions with DNA. Our data indicate that these compounds may be potentially useful in cancer treatment.

Inhibition of human prostate cancer (PC-3) cells and targeting of PC-3-derived prostate cancer stem cells with koenimbin, a natural dietary compound from Murraya koenigii (L) Spreng

BACKGROUND

Inhibition of prostate cancer stem cells (PCSCs) is an efficient curative maintenance protocol for the prevention of prostate cancer. The objectives of this study were to assess the efficiency of koenimbin, a major biologically active component of Murraya koenigii (L) Spreng, in the suppression of PC-3 cells and to target PC-3-derived cancer stem cells (CSCs) through apoptotic and CSC signaling pathways in vitro.

MATERIALS AND METHODS

The antiproliferative activity of koenimbin was examined using MTT, and the apoptotic detection was carried out by acridine orange/propidium iodide (AO/PI) double-staining and multiparametric high-content screening (HCS) assays. Caspase bioluminescence assay, reverse transcription polymerase chain reaction (RT-PCR), and immunoblotting were conducted to confirm the expression of apoptotic-associated proteins. Cell cycle analysis was investigated using flow cytometry. Involvement of nuclear factor-kappa B (NF-κB) was analyzed using HCS assay. Aldefluor™ and prostasphere formation examinations were used to evaluate the impact of koenimbin on PC-3 CSCs in vitro.

RESULTS

Koenimbin remarkably inhibited cell proliferation in a dose-dependent manner. Koenimbin induced nuclear condensation, formation of apoptotic bodies, and G0/G1 phase arrest of PC-3 cells. Koenimbin triggered the activation of caspase-3/7 and caspase-9 and the release of cytochrome c, decreased anti-apoptotic Bcl-2 and HSP70 proteins, increased pro-apoptotic Bax proteins, and inhibited NF-κB translocation from the cytoplasm to the nucleus, leading to the activation of the intrinsic apoptotic pathway. Koenimbin significantly (P<0.05) reduced the aldehyde dehydrogenase-positive cell population of PC-3 CSCs and the size and number of PC-3 CSCs in primary, secondary, and tertiary prostaspheres in vitro.

CONCLUSION

Koenimbin has chemotherapeutic potential that may be employed for future treatment through decreasing the recurrence of cancer, resulting in the improvement of cancer management strategies and patient survival.