Radioiodine-refractory differentiated thyroid cancer: Molecular mechanisms and therapeutic strategies for radioiodine resistance.

Radioiodine-refractory differentiated thyroid cancer (RAIR-DTC) is difficult to treat with radioactive iodine because of the absence of the sodium iodide transporter in the basement membrane of thyroid follicular cells for iodine uptake. This is usually due to the mutation or rearrangement of genes and the aberrant activation of signal pathways, which result in abnormal expression of thyroid-specific genes, leading to resistance of differentiated thyroid cancer cells to radioiodine therapy. Therefore, inhibiting the proliferation and growth of RAIR-DTC with multikinase inhibitors and other drugs or restoring its differentiation and then carrying out radioiodine therapy have become the first-line treatment strategies and main research directions. The drugs that regulate these kinases or signaling pathways have been studied in clinical and preclinical settings. In this review, we summarized the major gene mutations, gene rearrangements and abnormal activation of signaling pathways that led to radioiodine resistance of RAIR-DTC, as well as the medicine that have been tested in clinical and preclinical trials.

Preparation and evaluation of luteolin-loaded PLA-based shape memory gastroretentive drug delivery systems.

Luteolin, a natural flavonoid, is gaining growing attention for its potential in the treatment of gastric cancer. However, its clinical application is limited by factors such as poor aqueous solubility. This study aimed to develop a novel gastroretentive drug delivery system (GRDDS) to both enhance the oral bioavailability of luteolin and prolong its release and in vivo circulation time. Out of 10 luteolin-loaded PLA-based shape memory films prepared in this study, the LPC-PLA/PEG(7/3) formulation incorporated with PEG, HPMC, and NaHCO3 exhibited optimal properties in terms of drug release and inhibitory activity against SGC-7901 cells. Moreover, small-animal imaging revealed that LPC-PLA/PEG(7/3) exhibited a prolonged gastric retention time of approximately 8 h. Furthermore, the pharmacokinetic studies indicated a 354 % increase in the oral bioavailability of LPC-PLA/PEG(7/3) in rats compared to luteolin. In sum, a novel GRDDS was developed to enhance the relative bioavailability of luteolin, offering a potential strategy for practical oral administration.

A Reliable Approach for Fabricating Tissue-Mimicking Phantoms with Designated Dielectric Properties from 16 MHz to 3 GHz.

Tissue-mimicking dielectric phantoms are widely used to mimic the relative permittivity and conductivity of human tissues in various medical applications. The artificial material combinations determine the characterization of dialectic phantoms. However, a method that reliably determined the composition of artificial materials with designed values of dielectric properties and frequency is still lacking. In this work, we propose a method that easily determine the compositions of phantom to mimic the human tissues from 16 MHz to 3 GHz.

Design and evaluation of α-helix-based peptide inhibitors for blocking PD-1/PD-L1 interaction.

The current research in tumor immunotherapy indicates that blocking the protein-protein interaction (PPI) between PD-1 and its ligand, PD-L1, may be one of the most effective treatments for cancer patients. The α-helix is a common elements of protein secondary structure and is often involved in protein interaction. Thus, α-helix-based peptides could mimic proteins involved in such interactions and are also capable of modulating PPI in vivo. In this study, starting from a potential α-helix-rich protein, we designed a series of α-helix-based peptide candidates to block PD-1/PD-L1 interaction. These candidates were first screened using molecular docking and molecular dynamics simulations, and then their capacities to inhibit PD-1/PD-L1 interactions and to restore antitumor immune activities were investigated using the HTRF assay, SPR assay, cellular co-culture experiments and animal model experiments. Two peptides exhibited the best anti-tumor effects and the strong ability to restore the immunity of tumor-infiltrating T-cells. Further D-amino acid substitution was employed to improve the serum stability of peptide candidate, making the intravenous administration easier while maintaining the therapeutic efficacy. The resultant peptides showed promise as checkpoint inhibitors for application in tumor immunotherapy. These findings suggested that our strategy for developing peptides starting from an α-helical structure could be used in the design of bioactive inhibitors to potential block protein-protein interactions.

Periventricular Microglia Polarization and Morphological Changes Accompany NLRP3 Inflammasome-Mediated Neuroinflammation after Hypoxic-Ischemic White Matter Damage in Premature Rats.

White matter damage (WMD) is a primary cause of cerebral palsy and cognitive impairment in preterm infants, and no effective treatments are available. Microglia are a major component of the innate immune system. When activated, they form typical pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes and regulate myelin development and synapse formation. Therefore, they may play a pivotal role in hypoxic-ischemic (HI) WMD. Herein, we investigated neural inflammation and long-term microglia phenotypic polarization in a neonatal rat model of hypoxia-ischemia-induced WMD and elucidated the underlying pathophysiological processes. We exposed 3-day-old (P3) Sprague-Dawley rats to hypoxia (8% oxygen) for 2.5 hr after unilateral common carotid artery ligation. The activation of NLRP3 inflammatory bodies, microglia M1/M2 polarization, myelination, and synaptic development in our model were monitored 7, 14, and 21 days after birth. In addition, the Morris water maze test was performed on postnatal Day 28. We confirmed myelination disturbance in the periventricular white matter, abnormal synaptic development, and behavioral changes in the periventricular area during the development of HI WMD. In addition, we found an association between the occurrence and development of HI WMD and activation of the NLRP3 inflammasome, microglial M1/M2 polarization, and the release of inflammatory factors. NLRP3 inhibition can play an anti-inflammatory role by inhibiting the differentiation of microglia into the M1 phenotype, thereby improving myelination and synapse formation. In conclusion, microglia are key mediators of the inflammatory response and exhibit continuous phenotypic polarization 7-21 days after HI-induced WMD. This finding can potentially lead to a new treatment regimen targeting the phenotypic polarization of microglia early after HI-induced brain injury.

A mobile APP-based, customizable automated device for self-administered olfactory testing and an implementation of smell identification test.

Olfactory tests are used for the evaluation of ability to detect and identify common odors in humans psychophysically. Olfactory tests are currently administered by professionals with a set of given odorants. Manual administration of such tests can be labor and cost intensive and data collected as such are confounded with experimental variables, which adds personnel costs and introduces potential errors and data variability. For large-scale and longitudinal studies, manually recorded data must be collected and compiled from multiple sites. It is difficult to standardize the way data are collected and recorded. There is a need for a computerized smell test system for psychophysical and clinical applications. A mobile digital olfactory testing system (DOTS) was developed, consisting of an odor delivery system (DOTS-ODD) and a mobile application program (DOTS-APP) connected wirelessly. The University of Pennsylvania Smell Identification Test was implemented in DOTS and compared to its commercial product on a cohort of 80 normosmic subjects and a clinical cohort of 12 Parkinson's disease patients. A test-retest was conducted on 29 subjects of the normal cohort. The smell identification scores obtained from the DOTS and standard UPSIT commercial test are highly correlated (r = 0.714, P < 0.001), and test-retest reliability coefficient was 0.807 (r = 0.807, P < 0.001). The DOTS is customizable and mobile compatible, which allows for the implementation of standardized olfactory tests and the customization of investigators' experimental paradigms. The DOTS-APP on mobile devices offers capabilities for a broad range of on-site, online, or remote clinical and scientific chemosensory applications.

The effect of the subthreshold oscillation induced by the neurons' resonance upon the electrical stimulation-dependent instability.

Repetitive electrical nerve stimulation can induce a long-lasting perturbation of the axon's membrane potential, resulting in unstable stimulus-response relationships. Despite being observed in electrophysiology, the precise mechanism underlying electrical stimulation-dependent (ES-dependent) instability is still an open question. This study proposes a model to reveal a facet of this problem: how threshold fluctuation affects electrical nerve stimulations. This study proposes a new method based on a Circuit-Probability theory (C-P theory) to reveal the interlinkages between the subthreshold oscillation induced by neurons' resonance and ES-dependent instability of neural response. Supported by in-vivo studies, this new model predicts several key characteristics of ES-dependent instability and proposes a stimulation method to minimize the instability. This model provides a powerful tool to improve our understanding of the interaction between the external electric field and the complexity of the biophysical characteristics of axons.

Sensitivity investigation of open-ended coaxial probe in skin cancer detection.

Open-ended coaxial probe method is one of the most common modalities in measuring dielectric properties (DPs) of biological tissues. Due to the significant differences between the tumors and normal tissues in DPs, the technique can be used to detect skin cancer in the early stage. Although various studies have been reported, systematic assessment is in urgent need to advance it to clinical applications, for its parameters interactions and detecting limitations remained unclear. In this study, we aim to provide a comprehensive examination of this method, including the minimum detectable tumor size by using a three-layer skin model via simulation and demonstrated that open-ended coaxial probe method can be used for detection of early-stage skin cancer. The smallest detecting size are subject to different subtypes: for BCC, inside the skin is 0.5 mm radius × 0.1 mm height; for SCC, inside the skin is 1.4 mm × 1.3 mm in radius and height; the smallest distinguishing size of BCC is 0.6 mm × 0.7 mm in radius and height; for SCC is 1.0 mm × 1.0 mm in radius and height; for MM is 0.7 mm × 0.4 mm in radius and height. The experiment results showed that sensitivity was affected by tumor dimension, probe size, skin height, and cancer subtype. The probe is more sensitive to cylinder tumor radius than height growing on the surface of the skin while the smallest size probe is the most sensitive among the working probes. We provide a detailed systematic evaluation of the parameters employed in the method for further applications.

Lipid-Peptide-mRNA Nanoparticles Augment Radioiodine Uptake in Anaplastic Thyroid Cancer.

Restoring sodium iodide symporter (NIS) expression and function remains a major challenge for radioiodine therapy in anaplastic thyroid cancer (ATC). For more efficient delivery of messenger RNA (mRNA) to manipulate protein expression, a lipid-peptide-mRNA (LPm) nanoparticle (NP) is developed. The LPm NP is prepared by using amphiphilic peptides to assemble a peptide core and which is then coated with cationic lipids. An amphiphilic chimeric peptide, consisting of nine arginine and hydrophobic segments (6 histidine, C18 or cholesterol), is synthesized for adsorption of mRNA encoding NIS in RNase-free conditions. In vitro studies show that LP(R9H6) m NP is most efficient at delivering mRNA and can increase NIS expression in ATC cells by more than 10-fold. After intratumoral injection of NIS mRNA formulated in optimized LPm NP, NIS expression in subcutaneous ATC tumor tissue increases significantly in nude mice, resulting in more iodine 131 (131 I) accumulation in the tumor, thereby significantly inhibiting tumor growth. Overall, this work designs three arginine-rich peptide nanoparticles, contributing to the choice of liposome cores for gene delivery. LPm NP can serve as a promising adjunctive therapy for patients with ATC by restoring iodine affinity and enhancing the therapeutic efficacy of radioactive iodine.

The sirtuin family in health and disease.

Sirtuins (SIRTs) are nicotine adenine dinucleotide(+)-dependent histone deacetylases regulating critical signaling pathways in prokaryotes and eukaryotes, and are involved in numerous biological processes. Currently, seven mammalian homologs of yeast Sir2 named SIRT1 to SIRT7 have been identified. Increasing evidence has suggested the vital roles of seven members of the SIRT family in health and disease conditions. Notably, this protein family plays a variety of important roles in cellular biology such as inflammation, metabolism, oxidative stress, and apoptosis, etc., thus, it is considered a potential therapeutic target for different kinds of pathologies including cancer, cardiovascular disease, respiratory disease, and other conditions. Moreover, identification of SIRT modulators and exploring the functions of these different modulators have prompted increased efforts to discover new small molecules, which can modify SIRT activity. Furthermore, several randomized controlled trials have indicated that different interventions might affect the expression of SIRT protein in human samples, and supplementation of SIRT modulators might have diverse impact on physiological function in different participants. In this review, we introduce the history and structure of the SIRT protein family, discuss the molecular mechanisms and biological functions of seven members of the SIRT protein family, elaborate on the regulatory roles of SIRTs in human disease, summarize SIRT inhibitors and activators, and review related clinical studies.

IL-17D affects the chemokines and chemokine receptors of intestinal epithelial cells under hyperoxia.

IL-17D is a new member of the IL-17 family. Currently, it is believed that IL-17D can directly act on immune cells or may indirectly modulate immune responses by regulating cytokine expression. Herein, we hypothesized that IL-17D regulates the expression of chemokines in intestinal epithelial cells, in turn modulating the immune response within intestinal mucosa under hyperoxia. To explore this notion, newborn rats were divided into a hyperoxia group (85 % O2) and control group (21 % O2). Small intestinal tissues were obtained from neonatal rats at 3, 7, 10, and 14 days. Similarly, intestinal epithelial cells were treated by hyperoxia (85 % O2) as the hyperoxia group or were incubated under normal oxygen (21 % O2) as the control group. Finally, intestinal epithelial cells subjected to hyperoxia were treated with recombinant IL-17D and IL-17D antibodies for 24, 48, and 72 h. Immunohistochemistry, western blot, and reverse transcription-quantitative polymerase chain reaction were used to detect the expression levels of chemokines and chemokine receptors in intestinal tissues of newborn rats and intestinal epithelial cells. We found that hyperoxia affected chemokine expression both in vivo and in vitro. Under hyperoxia, IL-17D promoted the expression of CCL2, CCL25, CCL28, and CCR9 in intestinal epithelial cells while downregulating CCR2, CCR5, CCL5, and CCL20. Our findings provide a basis for further study on the effects of hyperoxia-induced intestinal inflammation and intestinal injury.

Co-expression network analysis for identification of novel biomarkers of bronchopulmonary dysplasia model.

Background: Bronchopulmonary dysplasia (BPD) is the most common neonatal chronic lung disease. However, its exact molecular pathogenesis is not understood. We aimed to identify relevant gene modules that may play crucial roles in the occurrence and development of BPD by weighted gene co-expression network analysis (WGCNA). Methods: We used RNA-Seq data of BPD and healthy control rats from our previous studies, wherein data from 30 samples was collected at days 1, 3, 7, 10, and 14. Data for preprocessing analysis included 17,613 differentially expressed genes (DEGs) with false discovery rate <0.05. Results: We grouped the highly correlated genes into 13 modules, and constructed a network of mRNA gene associations, including the 150 most associated mRNA genes in each module. Lgals8, Srpra, Prtfdc1, and Thap11 were identified as the key hub genes. Enrichment analyses revealed Golgi vesicle transport, coated vesicle, actin-dependent ATPase activity and endoplasmic reticulum pathways associated with these genes involved in the pathological process of BPD in module. Conclusions: This is a study to analyze data obtained from BPD animal model at different time-points using WGCNA, to elucidate BPD-related susceptibility modules and disease-related genes.

Uncovering the Key Targets and Therapeutic Mechanisms of Qizhen Capsule in Gastric Cancer through Network Pharmacology and Bioinformatic Analyses.

Objective. This study is aimed at screening out effective active compounds of Qizhen capsule (QZC) and exploring the underlying mechanisms against gastric cancer (GACA) by combining both bioinformatic analysis and experimental approaches. Weighted gene coexpression network analysis (WGCNA), network pharmacology, molecular docking simulation, survival analysis, and data-based differential gene and protein expression analysis were employed to predict QZC's potential targets and explore the underlying mechanisms. Subsequently, multiple experiments, including cell viability, apoptosis, and protein expression analyses, were conducted to validate the bioinformatics-predicted therapeutic targets. The results indicated that luteolin, rutin, quercetin, and kaempferol were vital active compounds, and TP53, MAPK1, and AKT1 were key targets. Molecular docking simulation showed that the four abovementioned active compounds had high binding affinities to the three main targets. Enrichment analysis showed that vital active compounds exerted therapeutic effects on GACA through regulating the TP53 pathway, MAPK pathway, and PI3K/AKT pathway. Furthermore, data-based gene expression analysis revealed that TP53 and JUN genes were not only differentially expressed between normal and GACA tissues but also correlated with clinical stages. In parallel, in vitro experimental results suggested that QZC exerted therapeutic effects on GACA by decreasing IC50 values, downregulating AKT expression, upregulating TP53 and MAPK expression, and increasing apoptosis of SGC-7901 cells. This study highlights the potential candidate biomarkers, therapeutic targets, and basic mechanisms of QZC in treating GACA, providing a foundation for new drug development, target mining, and related animal studies in GACA.

Design, synthesis, and biological characterization of a potent STAT3 degrader for the treatment of gastric cancer.

Gastric cancer is a common malignant tumor that threatens human health, and its occurrence and development mechanism is a complex process involving multiple genes and multiple signals. Signal transducer and activator of transcription 3 (STAT3) has been elucidated as a promising target for developing anticancer drugs in gastric cancer. However, there is no FDA-approved STAT3 inhibitor yet. Herein, we report the design and synthesis of a class of STAT3 degraders based on proteolysis-targeting chimeras (PROTACs). We first synthesized an analog of the STAT3 inhibitor S3I-201 as a ligand, using the cereblon (CRBN)/cullin 4A E3 ligase ligand pomalidomide to synthesize a series of PROTACs. Among them, the SDL-1 achieves the degradation of STAT3 protein in vitro, and exhibits good anti-gastric cancer cell proliferation activity, inhibits invasion and metastasis of MKN1 cell, and induces MKN1 cell apoptosis and arrests cell cycle at the same time. Our study shows that SDL-1 is a potent STAT3 degrader and may serve as a potential anti-gastric cancer drug, providing ideas for further development of drugs for clinical use.

In Silico Screening and Validation of PDGFRA Inhibitors Enhancing Radioiodine Sensitivity in Thyroid Cancer.

Aberrant activation of platelet-derived growth factor receptor α (PDGFRA) has been implicated in tumorigenesis and radioiodine resistance of thyroid cancer, indicating its therapeutic potential. In the present study, we confirmed the association between PDGFRA and radioiodine resistance in thyroid cancer using bioinformatics analysis and constructed a prediction model of PDGFRA inhibitors using machine learning and molecular docking approaches. We then performed a virtual screening of a traditional Chinese medicine (TCM) derived compound library and successfully identified 4',5,7-trimethoxyflavone as a potential PDGFRA inhibitor. Further characterization revealed a significant inhibitory effect of 4',5,7-trimethoxyflavone on PDGFRA-MAPK pathway activation, and that it could upregulate expression of sodium iodide symporter (NIS) as well as improve radioiodine uptake capacity of radioiodine-refractory thyroid cancer (RAIR-TC), suggesting it a potential drug lead for the development of new RAIR-TC therapy.

Effect of substrate stiffness on the mechanical properties of cervical cancer cells.

BACKGROUND: Cervical cancer microenvironment is involved in the regulation of the behavior, morphology, and mechanical properties of the cervical cancer cells. Integrins expressed on the cell membrane combine with the factors of the microenvironment to determine cervical cancer cells' properties. The mechanical properties of integrin-extracellular matrix (ECM) interactions are important for the mechanotransduction of cervical cancer cells. However, the quantified study on the adhesion force and binding probabilities between collagen and integrins on cervical cancer cells grown on different stiffness substrates have not been reported. METHODS: Polyacrylamide (PA) gel was used as substrate to mimic the mechanical microenvironment of cancer cells. ImageJ software was used to measure the perimeter and area of the cells. SiHa cells were stained with FITC phalloidine to observe the cytoskeleton. Atomic force microscopy (AFM) was used to measure the cell mechanical properties. RESULT: The perimeters of SiHa cells grown on different stiffness substrates were 63.4 ± 1.3, 102.8 ± 4.0, and 152.6 ± 4.1 µm, for soft, intermediate, and stiff substrates, respectively. These areas were 277.2 ± 13.3, 428.9 ± 26.0, and 1166.0 ± 63.2 µm2, for soft, intermediate, and stiff substrates, respectively. The Young's modulus of SiHa cells grown on stiff substrates (3.0 ± 0.02 kPa) was higher compared with those on soft substrates (0.6 ± 0.01 kPa) or intermediate substrates (bimodal distribution, 1.36 and 1.67 kPa). The adhesion force between the functionalized probe and SiHa cells grown on glass (55.65 ± 0.78 pN) was significantly greater than that on stiff (47.03 ± 0.85 pN), intermediate (34.07 ± 0.58 pN) and soft (27.94 ± 0.47 pN) substrates. The binding probabilities of the collagen-integrin of the four rigid substrates were significantly differed. CONCLUSION: The changes in substrate stiffness can obviously regulate SiHa cells' mechanical properties, such as the Young's modulus. The adhesion force and binding probabilities of SiHa cells both increased with increasing substrate strength.

Proteomic analysis of the effects of caffeine in a neonatal rat model of hypoxic-ischemic white matter damage.

AIM: White matter damage (WMD) is the main cause of cerebral palsy and cognitive impairment in premature infants. Although caffeine has been shown to possess neuroprotective effects in neonatal rats with hypoxic-ischemic WMD, the mechanisms underlying these protective effects are unclear. Herein, proteins modulated by caffeine in neonatal rats with hypoxic-ischemic WMD were evaluated. METHODS: We identified differential proteins and performed functional enrichment analyses between the Sham, hypoxic-ischemic WMD (HI), and HI+caffeine-treated WMD (Caffeine) groups. Confirmed the changes and effect of proteins in animal models and determined cognitive impairment via water maze experiments. RESULTS: In paraventricular tissue, 47 differential proteins were identified between the Sham, HI, and Caffeine groups. Functional enrichment analyses showed that these proteins were related to myelination and axon formation. In particular, the myelin basic protein (MBP), proteolipid protein, myelin-associated glycoprotein precursor, and sirtiun 2 (SIRT2) levels were reduced in the hypoxic-ischemic WMD group, and this effect could be prevented by caffeine. Caffeine alleviated the hypoxic-ischemic WMD-induced cognitive impairment and improved MBP, synaptophysin, and postsynaptic density protein 95 protein levels after hypoxic-ischemic WMD by preventing the HI-induced downregulation of SIRT2; these effects were subsequently attenuated by the SIRT2 inhibitor AK-7. CONCLUSION: Caffeine may have clinical applications in the management of prophylactic hypoxic-ischemic WMD; its effects may be mediated by proteins related to myelin development and synapse formation through SIRT2.

Mitochondrial complex I subunit deficiency promotes pancreatic α-cell proliferation.

OBJECTIVE: There is strong evidence that mitochondrial DNA mutations and mitochondrial dysfunction play a role in diabetes pathogenesis. The homozygous knock-in mtDNA mutator mouse is a model of premature aging due to the accumulation of mitochondrial DNA mutations. We used this mouse model to investigate the relationship between mitochondrial subunit expression and pancreatic islet cell composition. METHODS: Quadruple immunofluorescence was used to quantify mitochondrial subunit expression (complex I and IV) and cell composition in pancreatic islets from mitochondrial DNA mutator mice (PolgAmut/mut) and control C57BL/6 mice at 12 and 44 weeks of age. RESULTS: Mitochondrial complex I subunit expression was decreased in islets from 12 week PolgAmut/mut mice. This complex I deficiency persisted with age and was associated with decreased insulin staining intensity at 44 weeks. Complex I deficiency was greater in α-cells compared with ß-cells in islets from 44 week PolgAmut/mut mice. Islet cell composition was normal in 12 week PolgAmut/mut mice, but the ß: α cell ratio was decreased in islets from 44 week PolgAmut/mut mice. This was due to an increase in α-cell number linked to an increase in α-cell proliferation. CONCLUSION: Complex I deficiency promotes α-cell proliferation and alters islet cell composition.

Inhibition of STAT3 Signaling Pathway by Terphenyllin Suppresses Growth and Metastasis of Gastric Cancer.

Gastric cancer is a common type of malignant tumor with a relatively poor prognosis and presents a serious threat to global health. Signal Transducer and Activator of Transcription-3 (STAT3) has been strongly implicated in many cancers, and its constitutive activation promotes growth, angiogenesis, inflammation, and immune evasion. Therefore, considerable efforts have been put into developing effective and safe STAT3 inhibitors. In this study, we performed a virtual screening by molecular docking and found that terphenyllin, a marine-derived natural product, directly interacted with STAT3. We further found that terphenyllin inhibited the phosphorylation and activation of STAT3 and decreased the protein levels of STAT3-dependent target genes, including c-Myc and Cyclin D1. Subsequently, we demonstrated that terphenyllin exerted its potent anticancer efficacy against gastric cancer in vitro and in vivo. Terphenyllin concentration-dependently inhibited growth, proliferation, and colony formation and induced cell cycle arrest and apoptosis of gastric cancer cells in vitro. Moreover, terphenyllin treatment suppressed the tumor growth and metastasis in a gastric cancer orthotopic mouse model without notable toxicity in vivo. Taken together, our results indicated that terphenyllin exerts its anticancer activity by inhibiting the STAT3 signaling pathway and may serve as a potent STAT3 inhibitor for gastric cancer treatment.