Stabilization of mutant p53 (mutp53) in tumours greatly contributes to malignant progression. However, little is known about the underlying mechanisms and therapeutic approaches to destabilize ...mutp53. Here, through high-throughput screening we identify statins, cholesterol-lowering drugs, as degradation inducers for conformational or misfolded p53 mutants with minimal effects on wild-type p53 (wtp53) and DNA contact mutants. Statins preferentially suppress mutp53-expressing cancer cell growth. Specific reduction of mevalonate-5-phosphate by statins or mevalonate kinase knockdown induces CHIP ubiquitin ligase-mediated nuclear export, ubiquitylation, and degradation of mutp53 by impairing interaction of mutp53 with DNAJA1, a Hsp40 family member. Knockdown of DNAJA1 also induces CHIP-mediated mutp53 degradation, while its overexpression antagonizes statin-induced mutp53 degradation. Our study reveals that DNAJA1 controls the fate of misfolded mutp53, provides insights into potential strategies to deplete mutp53 through the mevalonate pathway-DNAJA1 axis, and highlights the significance of p53 status in impacting statins' efficacy on cancer therapy.
Proton pump inhibitors (PPIs) have been associated with adverse clinical outcomes amongst clopidogrel users after an acute coronary syndrome. Recent pre-clinical results suggest that this risk might ...extend to subjects without any prior history of cardiovascular disease. We explore this potential risk in the general population via data-mining approaches.
Using a novel approach for mining clinical data for pharmacovigilance, we queried over 16 million clinical documents on 2.9 million individuals to examine whether PPI usage was associated with cardiovascular risk in the general population.
In multiple data sources, we found gastroesophageal reflux disease (GERD) patients exposed to PPIs to have a 1.16 fold increased association (95% CI 1.09-1.24) with myocardial infarction (MI). Survival analysis in a prospective cohort found a two-fold (HR = 2.00; 95% CI 1.07-3.78; P = 0.031) increase in association with cardiovascular mortality. We found that this association exists regardless of clopidogrel use. We also found that H2 blockers, an alternate treatment for GERD, were not associated with increased cardiovascular risk; had they been in place, such pharmacovigilance algorithms could have flagged this risk as early as the year 2000.
Consistent with our pre-clinical findings that PPIs may adversely impact vascular function, our data-mining study supports the association of PPI exposure with risk for MI in the general population. These data provide an example of how a combination of experimental studies and data-mining approaches can be applied to prioritize drug safety signals for further investigation.
End-functionalised polymer grafted nanoparticles (PGNs) form bonds when their coronas overlap. The bonded interactions between the overlapping PGNs depend on the energy of the bonds (
U
). In the ...present study, oscillatory deformation imposed on a simple system with interacting PGNs placed on the vertices of a triangle is employed to examine the local dynamics as a function of energy of the bonds and the frequency of oscillation relative to the characteristic rupture frequency,
ω
0
= 2π
ν
exp(−
U
/
k
B
T
), of the bonds. In particular, the effect of functional anisotropy is studied by introducing bonds of two different energies between adjacent PGNs. A multicomponent model developed by Kadre and Iyer,
Macromol. Theory Simul.
, 2021,
30
, 2100005, that combines the features of effective interactions between PGNs, self-consistent field theory and master equation approach to study bond kinetics is employed to obtain the local dynamics. The resulting force-strain curves are found to exhibit a simple broken symmetry where
F
x
(
γ
,
&z.ggrda;
) ≠ −
F
x
(−
γ
,−
&z.ggrda;
) and
F
y
(
γ
,
&z.ggrda;
) ≠
F
y
(−
γ
,−
&z.ggrda;
) in systems with functional anisotropy. Fourier analysis of the dynamic response reveals that functional anisotropy leads to finite even harmonic terms and systematic variation of both the elastic and dissipative response from that of the isotropic systems. Furthermore, the intra-cycle variations in the strain stiffening and shear thickening ratios obtained from the analysis indicate that functional anisotropy leads to anisotropic nonlinear response.
Dynamics depends on anisotropy introduced
via
energy of bonded interactions between end-functionalised polymer grafted nanoparticles (PGNs).
Disruption of binding of two or more molecules to a protein surface is a common basis of inhibition of many biological activities. Smallmolecule inhibitors, antibodies, proteins, and peptidomimetics ...have been examined as ways to antagonize receptor activity. The peptide α-helix plays a crucial role in the function of many proteins. Hence, much effort has been invested in mimicking α-helices at the binding interface of two proteins to competitively inhibit their interactions. Peptide stapling involves choosing two amino acids on the same face of a native peptide sequence for substitution with non-native amino acids whose side chains can be "stapled" together. The focus of this review is to survey the prevalence in literature of stapled peptides and small-molecule antagonists of interactions of selected mammalian cancer targets, such as β-catenin, BH3-only members of the Bcl-2 family of proteins, eIF4E/G, estrogen receptor complexes, EZH2, Mdm2, Notch, p110α, and survivin. The increasing interest in protein targets currently considered to be "undruggable" with greater selectivity for existing targets, with the goal of overcoming the omnipresent problem of resistance, could be served well by utilizing information about protein-protein interactions to develop both small-molecule and stapled peptide inhibitors.
Breast cancer is a complex disease which cannot be defined merely by clinical parameters like lymph node involvement and histological grade, or by routinely used biomarkers like estrogen receptor ...(ER), progesterone receptor (PGR) and epidermal growth factor receptor 2 (HER2) in diagnosis and prognosis. Breast cancer originates from the epithelial cells. Keratins (K) are cytoplasmic intermediate filament proteins of epithelial cells and changes in the expression pattern of keratins have been seen during malignant transformation in the breast. Expression of the K8/18 pair is seen in the luminal cells of the breast epithelium, and its role in prognostication of breast cancer is not well understood.
In this study, we have modulated K8 expression to understand the role of the K8/18 pair in three different breast epithelium derived cell lines: non-transformed MCF10A, transformed but poorly invasive MDA MB 468 and highly invasive MDA MB 435. The up-regulation of K8 in the invasive MDA MB 435 cell line resulted in a significant decrease in proliferation, motility, in-vitro invasion, tumor volume and lung metastasis. The down-regulation of K8 in MDA MB 468 resulted in a significant increase in transformation potential, motility and invasion in-vitro, while MCF10A did not show any changes in cell transformation assays.
These results indicate the role of K8/18 in modulating invasion in breast cancer -its presence correlating with less invasive phenotype and absence correlating with highly invasive, dedifferentiated phenotype. These data may have important implications for prognostication of breast cancer.
Ion channels represent the molecular entities that give rise to the cardiac action potential, the fundamental cellular electrical event in the heart. The concerted function of these channels leads to ...normal cyclical excitation and resultant contraction of cardiac muscle. Research into cardiac ion channel regulation and mutations that underlie disease pathogenesis has greatly enhanced our knowledge of the causes and clinical management of cardiac arrhythmia. Here we review the molecular determinants, pathogenesis, and pharmacology of congenital Long QT Syndrome. We examine mechanisms of dysfunction associated with three critical cardiac currents that comprise the majority of congenital Long QT Syndrome cases: 1) I
, the slow delayed rectifier current; 2) I
, the rapid delayed rectifier current; and 3) I
, the voltage-dependent sodium current. Less common subtypes of congenital Long QT Syndrome affect other cardiac ionic currents that contribute to the dynamic nature of cardiac electrophysiology. Through the study of mutations that cause congenital Long QT Syndrome, the scientific community has advanced understanding of ion channel structure-function relationships, physiology, and pharmacological response to clinically employed and experimental pharmacological agents. Our understanding of congenital Long QT Syndrome continues to evolve rapidly and with great benefits: genotype-driven clinical management of the disease has improved patient care as precision medicine becomes even more a reality.
Delivery of Therapeutic Proteins Pisal, Dipak S.; Kosloski, Matthew P.; Balu-Iyer, Sathy V.
Journal of pharmaceutical sciences,
June 2010, Volume:
99, Issue:
6
Journal Article
Peer reviewed
Open access
The safety and efficacy of protein therapeutics are limited by three interrelated pharmaceutical issues, in vitro and in vivo instability, immunogenicity and shorter half-lives. Novel drug ...modifications for overcoming these issues are under investigation and include covalent attachment of poly(ethylene glycol) (PEG), polysialic acid, or glycolic acid, as well as developing new formulations containing nanoparticulate or colloidal systems (e.g., liposomes, polymeric microspheres, polymeric nanoparticles). Such strategies have the potential to develop as next generation protein therapeutics. This review includes a general discussion on these delivery approaches.
Multi-functional nanoparticle thin films are being used in various applications ranging from biosensing to photo-voltaics. In this study, we integrate two different numerical approaches to understand ...the interplay between the mechanical deformation and optical response of polymer grafted plasmonic nanoparticle (PGPN) arrays. Using numerical simulations we examine the deformation of thin films formed by end-functionalised polymer grafted nanoparticles subject to uniaxial elongation. The induced deformation causes the particles in the thin film network to rearrange their positions by two different mechanisms
viz.
sliding and packing. In sliding, the particles move in the direction of induced deformation. On the other hand, in packing, the particles move in a direction normal to that of the induced deformation. By employing a Green's tensor formulation in polarizable backgrounds for evaluating the optical response of the nanoparticle network, we calculate the evolution of the plasmonic response of the structure as a function of strain. The results indicate that the evolution of plasmonic response closely follows the deformation. In particular, we show that the onset of relative electric field enhancement of the optical response occurs when there is significant rearrangement of the constituent PGPNs in the array. Furthermore, we show that depending on the local packing/sliding and the polarization of the incident light there can be both enhancement and suppression of the SERS response.
Deformation induced modification of SERS response in polymer grafted plasmonic nanoparticle thin films yields insights into structure-function relationships in plasmonic networks.
Background
The development of antidrug antibodies, also termed inhibitors, against administered factor VIII (FVIII) is one of the major complications in the clinical management of hemophilia A. Once ...formed, these inhibitory antibodies abrogate the activity of FVIII, resulting in loss of hemostatic efficacy and patients are subjected to increased risk of bleeding tendencies. Current treatment options after inhibitor development are expensive and ineffective in some cases. Therefore, treatment strategies that can prevent inhibitor formation is an effective approach in the management of hemophilia A.
Objectives
We aimed to evaluate and discuss the use of a tolerogenic form of FVIII as an immunotherapy strategy to prevent inhibitor risk.
Methods
FVIII was associated with nanoparticles containing lysophosphatidylserine (Lyso‐PS) and administered to hemophilia A mice via intravenous route. These animals then received weekly rechallenge injections with free FVIII, and plasma was collected at the end of the study to evaluate for inhibitor development. To investigate whether Lyso‐PS nanoparticles influence the plasma survival of FVIII, a pharmacokinetic study following a single intravenous administration of FVIII in the presence and absence of Lyso‐PS nanoparticles was performed. For dosing convenience, the tolerogenic effect of Lyso‐PS nanoparticles following oral administration was also examined.
Results and conclusions
The results demonstrated that FVIII associated with Lyso‐PS nanoparticles significantly reduced inhibitor development while improving plasma survival of FVIII following intravenous administration, suggesting a multifunctional FVIII form to improve clinical utility. Additionally, reduction in inhibitor formation can also be achieved using Lyso‐PS nanoparticles through the user‐friendly oral route of administration.
Breast cancer is the most frequently diagnosed cancer in women, and one of the leading causes of cancer-related deaths worldwide. Recent evidences indicate that dietary agents such as resveratrol may ...inhibit cancer progression through modulation of microRNAs (miRNAs). We demonstrate that resveratrol regulates apoptotic and cell cycle machinery in breast cancer cells by modulating key tumor-suppressive miRNAs including miR-125b-5p, miR-200c-3p, miR-409-3p, miR-122-5p and miR-542-3p. Resveratrol-mediated miRNA modulation regulates key anti-apoptotic and cell cycle proteins including Bcl-2, X-linked inhibitor of apoptosis protein and CDKs, which are critical for its activity. Modulating miRNAs with mimics or inhibitors further validated a key role for miR-542-3p in MCF-7 and miR-122-5p in MDA-MB-231 breast cancer cell death in response to resveratrol. In conclusion, this study reveals novel miRNAs modulated by resveratrol that have a key role in breast cancer cell death.
PDF
