Interactions between Lipid Vesicle Membranes and Single Amino Acid Fibrils: Probable Origin of Specific Neurological Disorders.

Amyloid fibrils are known to be responsible for several neurological disorders, like Alzheimer's disease (AD), Parkinson's disease (PD), etc. For decades, mostly proteins and peptide-based amyloid fibrils have been focused on, and the topic has acknowledged the rise, development, understanding of, and controversy, as well. However, the single amino acid based amyloid fibrils, responsible for several disorders, such as phenylketonuria, tyrosenimia type II, hypermethioninemia, etc., have gotten scientific attention lately. To understand the molecular level pathogenesis of such disorders originated due to the accumulation of single amino acid-based amyloid fibrils, interaction of these fibrils with phospholipid vesicle membranes is found to be an excellent cell-free in vitro setup. Based on such an in vitro setup, these fibrils show a generic mechanism of membrane insertion driven by electrostatic and hydrophobic effects inside the membrane that reduces the integral rigidity of the membrane. Alteration of such fundamental properties of the membrane, therefore, might be referred to as one of the prime pathological factors for the development of these neurological disorders. Hence, such interactions must be investigated in cellular and intracellular compartments to design suitable therapeutic modulators against fibrils.

Kaempferol with Verapamil impeded panoramic chemoevasion pathways in breast cancer through ROS overproduction and disruption of lysosomal biogenesis.

BACKGROUND: Reactive oxygen species (ROS) at low level promotes cell survival through lysosome induced autophagy induction. Glucose stress induced acidosis, hypoxia, ROS, upregulates markers related to cancer stemness and multidrug resistance. Also, lysosomal upregulation is proposed to be one of the important indicators of cell survival under ROS induced stress. Studies supported that, stimulation of Lysosome-TFEB-Ca2+ cascade has important role in induction of chemoresistance and survival of cancerous cells. PURPOSE: To observe the effect of synergistic drug combination, Kaempferol and Verapamil on markers regulating chemoevasion, tumor stemness & acidosis as well as lysosome upregulation pathways, under low as well as high glucose conditions. HYPOTHESIS: Based on our earlier observation as well as previous reports, we hypothesized, our drug combination Kaempferol with Verapamil could attenuate markers related to chemoevasion, tumor stemness & acidosis as well as lysosome-TFEB-Ca2+ pathway, all of which have indispensable association and role in chemoresistance. METHODS: RNA and protein expression of candidate genes, along with ROS production and Ca2+ concentrations were measured in ex vivo models in altered glucose conditions upon treatment with KV. Also, computational approaches were utilized to hypothesize the mechanism of action of the drug combination. PCR, IHC, western blotting and molecular docking approaches were used in this study. RESULTS: The overproduction of ROS by our candidate drugs KV, downregulated the chemoresistance and tumor acidosis markers along with ATP1B1 and resulted in lysosomal disruption with reduction of Ca2+ release, diminishing TFEB expression under low glucose condition. An anomalous outcome was observed in high glucose conditions. We also observed KV promoted the overproduction of ROS levels thereby inducing autophagy-mediated cell death through the upregulation of LC3-II and p62 in low glucose conditions. The ex vivo studies also corroborate with in silico study that exhibited the parallel outcome. CONCLUSION: Our ex-vivo and in-silico studies revealed that our candidate drug combination KV, could effectively target several pathways regulating chemoresistance, that were not hitherto studied in the same experimental setup and thus may be endorsed for therapeutic purposes.

Interplay of gut microbiome, fatty acids, and the endocannabinoid system in regulating development, progression, immunomodulation, and chemoresistance of cancer.

The roles of gut microorganisms in cancer are diverse. Studies on metagenomics and bioinformatics have documented diverse microbial etiology in different tumors. Evidence supports that a commensal microbiome could provide a promising strategy to treat and prevent cancer through interference in several biologic processes, such as host cell survival and death, host immune function, inflammation, oncogenic signaling, and several hormone receptor signaling and detoxification pathways. The cumulative evidence recommends that metabolites of commensal gut microorganisms (e.g., short-chain fatty acids, omega-3 and -6 fatty acids) play an important role in cancer prevention, with a robust antiproliferative effect of omega-3 fatty acids. Intriguingly, the endocannabinoid system (omega-3 and -6 fatty acid-derived neurotransmitter of the body) shows diverse effects on cancer prevention and oncogenesis depending on the context of the tumor microenvironment. Thus, an interplay of gut microorganisms with their fatty acid metabolites and the endocannabinoid system play an important role in the development, progression, immunomodulation, and chemoresistance of cancer. In this review, we highlight aspects of the current knowledge of and interactions between the microbiome with fatty acids and the host endocannabinoid system. We also document their effect on host immunomodulation and chemoresistance, and discuss how these insights might translate into future development of microbiome-targeted therapeutic interventions.

Kaempferol attenuates viability of ex-vivo cultured post-NACT breast tumor explants through downregulation of p53 induced stemness, inflammation and apoptosis evasion pathways.

Early onset of chemotherapy evasion is a therapeutic challenge. Chemotherapy-induced upregulation of stem cell markers imparts invasiveness and metastatic property to the resident tumor. The efficacy of Kaempferol in attenuating epithelial to mesenchymal transition has earlier been established in the breast cancer cell. In our study population, progression-free survival was observed to be statistically more significant in post-NACT low-grade tumors than the high-grade tumors. Further, in post-NACT TNBCs, high-grade tumors showed a preponderance of strong nuclear p53 expression and very low expression of Caspase 3, indicating that, altered p53 expression predisposes these tumors to apoptosis escape and up-regulation of stemness markers. Herein, we report the robust efficacy of Kaempferol on ex-vivo grown breast tumors, derived from post-NACT TNBC patients, through downregulation of nuclear p53, CD44, ALDH1, NANOG, MDR1, Ki67, BCL2 and upregulation of Caspase 3. Such tumors also showed concurrent deregulated RNA and protein expression of CD44, NANOG, ALDH1 and MDR1 with upregulation of Caspase 3 and cleaved Caspase 3, upon Kaempferol treatment. Validation of efficacy of the treatment dosage of Kaempferol through immunophenotyping on MDA-MB-231, suggested that Kaempferol at its IC-50 dosage was effective against CD44 and CD326 positive breast cancer through deregulating their expression. Protein-protein interaction network through STRING pathway analysis and co-expression study of candidate proteins showed the highest degree of co-expression of p53 and KI-67, CD44, NF- kappaB, ALDH1, NANOG, MDR1, and BCL2. Thus, potentially targetable oncogenic protein markers, that are susceptible to downregulation by Kaempferol, provides insight into biomarker-driven therapeutic approaches with it.

Amyloids Formed by Nonaromatic Amino Acid Methionine and Its Cross with Phenylalanine Significantly Affects Phospholipid Vesicle Membrane: An Insight into Hypermethioninemia Disorder.

The incorrect metabolic breakdown of the nonaromatic amino acid methionine (Met) leads to the disorder called hypermethioninemia via an unknown mechanism. To understand the molecular level pathogenesis of this disorder, we prepared a DMPC lipid membrane, the mimicking setup of the cell membrane, and explored the effect of the millimolar level of Met on it. We found that Met forms toxic fibrillar aggregates that disrupt the rigidity of the membrane bilayer, and increases the dynamic response of water molecules surrounding the membrane as well as the heterogeneity of the membrane. Such aggregates strongly deform red blood cells. This opens the requirement to consider therapeutic antagonists either to resist or to inhibit the toxic amyloid aggregates against hypermethioninemia. Moreover, such disrupting effect on membrane bilayer and cytotoxicity along with deformation effect on RBC by the cross amyloids of Met and Phenylalanine (Phe) was found to be most virulent. This exclusive observation of the enhanced virulent effect of the cross amyloids is expected to be an informative asset to explain the coexistence of two amyloid disorders.

Antibiofilm and anticancer activities of unripe and ripe Azadirachta indica (neem) seed extracts.

BACKGROUND: Antibiotic resistances of pathogens and breast cancer warrant the search for new alternative strategies. Phytoextracts can eradicate microbe-borne diseases as well as cancer with lower side effects compared to conventional antibiotics. AIM: Unripe and ripe Azadirachta indica (neem) seed extracts were explored as potential antibiofilm and anticancer agents in combating multidrug-resistant infectious bacteria as well as anticancer agents against the MDR breast cancer cell lines. METHODS: Shed-dried neem seeds (both unripe and ripe) were pulverized and extracted using methanol. The chemical components were identified with FTIR and gas chromatography - mass spectrometry. Antibiofilm activity of neem seed extracts were assessed in terms of minimum biofilm inhibitory concentration (MBIC), minimum biofilm eradication concentration (MBEC), and fluorescence microscopic studies on Staphylococcus aureus and Vibrio cholerae. Bacterial cells were studied by fluorescence microscopy using acridine orange/ethidium bromide as the staining agents. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were evaluated to observe the antibacterial activities. Cytotoxicity of the extracts against human blood lymphocytes and the anticancer activity against drug-resistant breast cancer cell lines were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and fluorescence-activated cell sorting (FACS) studies. RESULTS: 4-Ethyl-2-hydroxy-2-cyclopentene-1-one, phthalic acid, and 2-hexyl-tetrahydro thiophane were the major compounds in unripe neem seed, whereas 3,5-dihydroxy-6-methyl-2,3-dihydro-4-H-pyran-4-one and 4-ethylbenzamide were predominant in ripe neem seed. Triazine derivatives were also common for both the extracts. MBIC values of unripe and ripe neem seed extracts for S. aureus are 75 and 100 µg/mL, respectively, and for V. cholerae, they are 100 and 300 µg/mL, respectively. MBEC values of unripe and ripe seed extracts are 500 and 300 µg/mL, respectively for S. aureus and for V. cholerae the values are 700 and 500 µg/mL, respectively. Fluorescence microscopic studies at 16 and 24 h, after bacterial culture, demonstrate enhanced antibiofilm activity for the ripe seed extract than that of the unripe seeds for both the bacteria. MTT assay reveals lower cytotoxicity of both the extracts towards normal blood lymphocytes, and anticancer activity against breast cancer cell line (MDA-MB-231) with superior activity of ripe seed extract. FACS studies further supported higher anticancer activity for ripe seed extract. CONCLUSIONS: Methanolic extract of neem seeds could substantially inhibit and eradicate biofilm along with their potent antibacterial and anticancer activities. Both the extracts showed higher antibiofilm and antibacterial activity against S. aureus (gram-positive) than V. cholerae (gram-negative). Moreover, ripe seed extract showed higher antibiofilm and anticancer activity than unripe extracts.

Deregulation of the CD44-NANOG-MDR1 associated chemoresistance pathways of breast cancer stem cells potentiates the anti-cancer effect of Kaempferol in synergism with Verapamil.

Chemoresistance is an imminent therapeutic challenge for breast cancer. Previous evidence suggests that breast cancer stem cells (BCSC) develop resistance through upregulation of stemness and chemo-evasion markers viz. SOX2, OCT4, NANOG, MDR1 and CD44, following anticancer chemotherapeutic treatments. Early studies suggest an inhibitory role of Kaempferol in BCSC propagation through downregulation of epithelial to mesenchymal transition. We hypothesized that the pathway involved in chemoresistance could be effectively addressed through Kaempferol (K), alone or in combination with Verapamil (V), which is an inhibitor of MDR1. We used K in combination with V, in multiple assays to determine if there was an inhibitory effect on BCSC. Both K and KV attenuated pH-dependent mammosphere formation in primary BCSC and MDA-MB-231 cells. RNA and protein (immunocytochemistry, western blot) expression of candidate markers viz. SOX2, OCT4, NANOG, MDR1 and CD44 were carried out in the presence or absence of candidate drugs in ex-vivo grown primary BCSC and MDA-MB-231 cell line. Immunoprecipitation assay, cell cycle analysis was carried out in MDA-MB-231. Our candidate drugs were not only anti-proliferative, but also downregulated candidate genes expression at RNA and protein level in both settings, with more robust efficacy in KV treatment than K; induced G2/M dependent cell cycle arrest, and interrupted physical association of CD44 with NANOG as well as MDR1 in MDA-MB-231. In primary tumor explant but not in adjacent normal tissue, our candidate drugs K and KV induced robust γH2AX expression. Thus, our candidate drugs are effective in attenuating BCSC survival.

Formation of lipid tubules induced by a sugar-like molecule myo-inositol.

The sugar-like molecule myo-inositol (InOH) bears an uncanny structural resemblance to the pyranose form of the sugar D-glucose (DG). InOH and its derivatives play a pivotal role in cell biology; whereby its interaction with the model membrane needs to be studied. Here, we have demonstrated that lipid tubules are formed as a result of the above-said interactions and that these interactions can be prevented by using hydroxyl protected InOH derivatives. We have tried to elucidate the nature of the InOH-membrane interactions by comparing them with DG-membrane interactions and have proposed a mechanism for the same.

The Dietary Nutrient Trimethylamine N-Oxide Affects the Phospholipid Vesicle Membrane: Probable Route to Adverse Intake.

Trimethylamine N-oxide (TMAO), a choline-containing dietary supplement obtained from red meat, egg, and other animal resources, on excess accumulation is known to cause cardiovascular diseases (CVDs) like atherosclerosis. To understand the molecular mechanism of the pathogenesis of TMAO-induced CVDs, we have set up 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane in water that mimicked the endothelial cell membrane-blood interface of the artery wall and investigated the effect of an elevated concentration of TMAO on the membrane. We found that TMAO exerts an "action at a distance" mechanism through electrostatic force of attraction that significantly alters various properties of the membrane, like hydrophobicity, lateral organization, and interfacial water dynamics, which elevates the rigidity of the membrane. Such an effect was found to be further amplified in the presence of known causes of CVDs, i.e., high content of cholesterol (Chol). Therefore, TMAO-induced membrane rigidity may restrict the intrinsic elasticity of an artery membrane, expected to be introducing "hardening of the arteries", which makes the membrane atherosclerotic.

Influence of a Polyneurotransmitter on DNA-Mediated Förster-Based Resonance Energy Transfer: A Path Leading to White Light Generation.

The physiologically important biomolecule, dopamine (DA), shows strong self-oxidation and aggregation behaviors, which have been controlled and modulated to result in fluorescent polydopamine (F-PDA) nanoparticles. On the other hand, the simultaneous binding of two diverse deoxyribonucleic acid (DNA) binding probes, 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and ethidium bromide (EtBr), has been elaborately established to follow the Förster-based resonance energy transfer (FRET) pathway. The comparative understanding of this DNA-mediated FRET in three media, phosphate buffer saline (PBS) of pH 7.4, DA, and F-PDA, has concluded that the FRET efficiency in the three media follows the order: PBS > DA > F-PDA. This controlled FRET in the fluorescent F-PDA matrix serves a pivotal role for efficient white light (WL) generation with excellent Commission Internationale de l'Eclairage (CIE) parameters that match well with that of pure WL emission. The obtained WL emission has been shown to be very specific with respect to concentrations of different participating components and the excitation wavelength of the illuminating source. Furthermore, the optical properties of the WL emitting solution have been observed to be retained excellently inside the well-known agarose gel matrix. Finally, the mechanistic pathway behind such a FRET-based WL generation has been established in detail, and to the best of our knowledge, the current study offers the first and only report that discloses the influence of a fluorescent polyneurotransmitter matrix for successful generation of WL emission.

Self-assembly of artificial sweetener aspartame adversely affects phospholipid membranes: plausible reason for its deleterious effects.

The prolonged intake of the artificial sweetener aspartame is known to have deleterious effects. Our biophysical experimentations indicate that aspartame forms self-assembled cytotoxic fibrillar etiologies that affect the intrinsic integrity of the phospholipid membrane bilayer through electrostatic interaction and hydrophobic insertion, thereby making the membrane less rigid and more heterogeneous.

Phenylalanine Interacts with Oleic Acid-Based Vesicle Membrane. Understanding the Molecular Role of Fibril-Vesicle Interaction under the Context of Phenylketonuria.

In the present contribution, on the basis of a spectroscopic and microscopic investigation, the characterization and photophysics of various assemblies of oleic acid/oleate solution at three pH values, namely, 8.28, 9.72, and 11.77, were explored. The variation in the dynamic response of aqua molecules in and around the assemblies has been interrogated by a picoseconds solvation dynamics experiment using a time-correlated single-photon counting setup employing coumarin-153 as a probe. On the one hand, the time-resolved fluorescence anisotropy measurement along with the fluorescence correlation spectroscopy experiment was executed to extract information regarding the comparison of the extent of the internal restricted confinement of these assemblies. On the other hand, an effort to investigate the cross-interaction between the self-assembled architectures of l-phenylalanine (l-Phe), responsible for phenylketonuria (PKU) disorder, and the oleic acid at the vesicle-forming pH established that the l-Phe fibrillar morphologies strongly alter the dynamic properties of the vesicle membrane formed by the oleic acid. Specifically, the interaction of the l-Phe assemblies with the oleic acid vesicle membrane is found to introduce the flexibility of the vesicle membrane and alter the hydration properties of the membrane. To track the fibril-induced alterations of the oleic acid vesicle properties, various spectroscopic and microscopic investigations were performed. The mutual reconciliation of the experimental outputs, therefore, portrays the state of the art, which accounts for the fibril-induced alterations of the properties of the oleic acid vesicle membrane, the mimicking setup of the cellular membrane, thereby informing us that alterations of such a property of the membrane should be taken into active consideration during the rational development of therapeutic modulators against disorders like PKU.

A Comparative Study on DMSO-Induced Modulation of the Structural and Dynamical Properties of Model Bilayer Membranes.

Modulating the structures and properties of biomembranes via permeation of small amphiphilic molecules is immensely important, having diverse applications in cell biology, biotechnology, and pharmaceuticals, because their physiochemical and biological interactions lead to new pathways for transdermal drug delivery and administration. In this work, we have elucidated the role of dimethyl sulfoxide (DMSO), broadly used as a penetration-enhancing agent and cryoprotective agent on model lipid membranes, using a combination of fluorescence microscopy and time-resolved fluorescence spectroscopy. Spatially resolved fluorescence lifetime imaging microscopy (FLIM) has been employed to unravel how the fluidity of the DMSO-induced bilayer regulates the structural alteration of the vesicles. Moreover, we have also shown that the dehydration effect of DMSO leads to weakening of the hydrogen bond between lipid headgroups and water molecules and results in faster solvation dynamics as demonstrated by femtosecond time-resolved fluorescence spectroscopy. It has been gleaned that the water dynamics becomes faster because bilayer rigidity decreases in the presence of DMSO, which is also supported by time-resolved rotational anisotropy measurements. The enhanced diffusivity and increased membrane fluidity in the presence of DMSO are further ratified at the single-molecule level through fluorescence correlation spectroscopy (FCS) measurements. Our results indicate that while the presence of DMSO significantly affects the 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl-rac-glycero-3-phosphatidylcholine (DPPC) bilayers, it has a weak effect on 1,2-dimyristoyl-sn-glycero-3-phospho-rac-glycerol (DMPG) vesicles, which might explain the preferential interaction of DMSO with the positively charged choline group present in DMPC and DPPC vesicles. The experimental findings have also been further verified with molecular dynamics simulation studies. Moreover, it has been observed that DMSO is likely to have a differential effect on heterogeneous bilayer membranes depending on the structure and composition of their headgroups. Our results illuminate the importance of probing the lipid structure and composition of cellular membranes in determining the effects of cryoprotective agents.

Denaturant-Mediated Modulation of the Formation and Drug Encapsulation Responses of Gold Nanoparticles.

The extensive and diversified applications of the well-known plasmonic nanoparticle systems along with their easy and environment-friendly synthesis strategies drive us to investigate in-depth this important research field. In the current scenario, our present study deals with an important plasmonic nanomaterial, i.e., globular protein, and human serum albumin (HSA)-conjugated gold nanoparticle (HSA-Au NP) system. The well-known chemical denaturants, urea and guanidine hydrochloride (GdnHCl or GnHCl), are investigated to show detrimental effects toward the formation of gold nanoparticles; however, the effect of GdnHCl is observed to be much prominent compared to that of urea. The synthesized nanoparticle system is found to be highly biocompatible from the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based cytotoxicity assay, and therefore, the applications of encapsulation of the well-known anticancer drug molecule, doxorubicin hydrochloride (Dox), in the nanoparticle system are further studied. In this drug encapsulation study, drug-metal complexation between Dox and HAuCl4·3H2O has been discussed elaborately. Similar to the nanoparticle formation, the effects of denaturants on drug encapsulation have also been discovered, and interestingly, it has been observed that urea plays a positive role, whereas GdnHCl plays a negative or detrimental role toward drug encapsulation in the synthesized gold nanoparticle system. The detailed photophysical mechanisms behind the drug encapsulation in the synthesized plasmonic nanosystem at every stage have also been explored. Overall, this study will conclusively explain the influences of the extensively used chemical denaturants on the synthesis and drug encapsulation behaviors of a well-known protein-conjugated gold nanoparticle, and as a consequence, it can be highly useful and acceptable to the biomedical and pharmaceutical research communities.

Antagonist Effects of l-Phenylalanine and the Enantiomeric Mixture Containing d-Phenylalanine on Phospholipid Vesicle Membrane.

One of the congenital flaws of metabolism, phenylketonuria (PKU), is known to be related to the self-assembly of toxic fibrillar aggregates of phenylalanine (Phe) in blood at elevated concentrations. Our experimental findings using l-phenylalanine (l-Phe) at millimolar concentration suggest the formation of fibrillar morphologies in the dry phase, which in the solution phase interact strongly with the model membrane composed of 1,2-diacyl-sn-glycero-phosphocholine (LAPC) lipid, thereby decreasing the rigidity (or increasing the fluidity) of the membrane. The hydrophobic interaction, in addition to the electrostatic attraction of Phe with the model membrane, is found to be responsible for such phenomena. On the contrary, various microscopic observations reveal that such fibrillar morphologies of l-Phe are severely ruptured in the presence of its enantiomer d-phenylalanine (d-Phe), thereby converting the fibrillar morphologies into crushed flakes. Various biophysical studies, including the solvation dynamics experiment, suggest that this l-Phe in the presence of d-Phe, when interacting with the same model membrane, now reverts the rigidity of the membrane, i.e., increases the rigidity of the membrane, which was lost due to interaction with l-Phe exclusively. Fluorescence anisotropy measurements also support this reverse rigid character of the membrane in the presence of an enantiomeric mixture of amino acids. A comprehensive understanding of the interaction of Phe with the model membrane is further pursued at the single-molecular fluorescence detection level using fluorescence correlation spectroscopy (FCS) experiments. Therefore, our experimental conclusion interprets a linear correlation between increased permeability and enhanced fluidity of the membrane in the presence of l-Phe and certifies d-Phe as a therapeutic modulator of l-Phe fibrillar morphologies. Further, the study proposes that the rigidity of the membrane lost due to interaction with l-Phe was reinstated-in fact, increased-in the presence of the enantiomeric mixture containing both d- and l-Phe.

Surface Ligand-Controlled Wavelength-Tunable Luminescence of Gold Nanoclusters: Cellular Imaging and Smart Fluorescent Probes for Amyloid Detection.

Gold nanoclusters (Au NCs) are an emerging class of fluorescent nanomaterials due to their fascinating chemical or physical properties and atomically precise structures; hence, they have been widely used in the field of biosensing and bioimaging. In this article, we demonstrate the green synthesis of orange, yellow, green, and cyan emitting Au NCs by core etching and ligand exchange methodology. Our investigation reveals that the chain length of the mercaptan acids, which are present on the surface of the Au NCs, controls the optical and electronic properties of the synthesized NCs. The steady-state and time-resolved spectroscopic data suggest that the emission properties of Au NCs mainly originate from the ligand to metal charge transfer (LMCT) transition. Alterations of the optical properties of these Au NCs can be proposed due to the difference in the core size of the Au NCs, which is strongly influenced by the surface-capping ligands. These NCs are highly biocompatible and nontoxic as evidenced by the cell viability and cellular uptake studies. By virtue of this, our as-synthesized NCs have been successfully used as excellent intracellular fluorescent imaging probes. Interestingly, fluorescence properties of Au NCs can efficiently probe the protein amyloids associated with several neurodegenerative diseases. To facilitate research in the field of amyloidosis, we have demonstrated fluorescence lifetime imaging microscopy (FLIM) and fluorescence correlation spectroscopy (FCS) as two advanced tools to probe the aggregation of proteins and to monitor the physical interactions between proteins and NCs. It has been observed that the hydrophobicity of the NC surface can trigger the amyloid detection capability of Au NCs. Owing to these unique optical and attractive biological properties coupled with the imaging capability, these ultrasmall-sized Au NCs may enable in vivo detection of amyloids in the near future.

An insight into metastasis: Random or evolving paradigms?

Mechanical or fostered molecular events define metastatic cascade. Three distinct sets of molecular events characterize metastasis, viz invasion of extracellular matrix; angiogenesis, vascular dissemination and anoikis resistance; tumor homing and relocation of tumor cells to selective organ. Invasion of extracellular matrix requires epithelial to mesenchymal transition through disrupted lamellopodia formation and contraction of actin cytoskeleton; aberration of Focal adhesion complex formation involving integrins and the extracellular matrix; degradation of extracellular matrix by matrix metalloproteases; faulty immune surveillance in tumor microenvironment and an upregulated proton efflux pump NHE1 in tumors. Vascular dissemination and anoikis resistance depend upon upregulation of integrins, phosphorylation of CDCP1, attenuated apoptotic pathways and upregulation of angiogenesis. Tumor homing depends on recruitment of mesenchymal stem cells, expression on chemokines and growth factors, upregulated stem cell renewal pathways. Despite of many potential challenges in curbing metastasis, future targeted therapies involving immunotherapy, stem cell engineered and oncolytic virus based therapy, pharmacological activation of circadian clock are held promising. To sum up, metastasis is a complex cascade of events and warrants detailed molecular understanding for development of therapeutic strategies.