Interferon-γ induces tumor resistance to anti-PD-1 immunotherapy by promoting YAP phase separation.

Interferon-γ (IFN-γ)-mediated adaptive resistance is one major barrier to improving immunotherapy in solid tumors. However, the mechanisms are not completely understood. Here, we report that IFN-γ promotes nuclear translocation and phase separation of YAP after anti-PD-1 therapy in tumor cells. Hydrophobic interactions of the YAP coiled-coil domain mediate droplet initiation, and weak interactions of the intrinsically disordered region in the C terminus promote droplet formation. YAP partitions with the transcription factor TEAD4, the histone acetyltransferase EP300, and Mediator1 and forms transcriptional hubs for maximizing target gene transcriptions, independent of the canonical STAT1-IRF1 transcription program. Disruption of YAP phase separation reduced tumor growth, enhanced immune response, and sensitized tumor cells to anti-PD-1 therapy. YAP activity is negatively correlated with patient outcome. Our study indicates that YAP mediates the IFN-γ pro-tumor effect through its nuclear phase separation and suggests that YAP can be used as a predictive biomarker and target of anti-PD-1 combination therapy.

LATS2 condensates organize signalosomes for Hippo pathway signal transduction.

Biomolecular condensates have been proposed to mediate cellular signaling transduction. However, the mechanism and functional consequences of signal condensates are not well understood. Here we report that LATS2, the core kinase of the Hippo pathway, responds to F-actin cytoskeleton reduction and forms condensates. The proline-rich motif (PRM) of LATS2 mediates its condensation. LATS2 partitions with the main components of the Hippo pathway to assemble a signalosome for LATS2 activation and for its stability by physically compartmentalizing from E3 ligase FBXL16 complex-dependent degradation, which in turn mediates yes-associated protein (YAP)-transcriptional coactivator with PDZ-binding motif (TAZ) recruitment and inactivation. This oncogenic FBXL16 complex blocks LATS2 condensation by binding to the PRM region to promote its degradation. Disruption of LATS2 condensation leads to tumor progression. Thus, our study uncovers that the signalosomes assembled by LATS2 condensation provide a compartmentalized and reversible platform for Hippo signaling transduction and protein stability, which have potential implications in cancer diagnosis and therapeutics.

Accelerating therapeutics development during a pandemic: population pharmacokinetics of the long-acting antibody combination AZD7442 (tixagevimab/cilgavimab) in the prophylaxis and treatment of COVID-19.

AZD7442 is a combination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-neutralizing antibodies, tixagevimab and cilgavimab, developed for pre-exposure prophylaxis (PrEP) and treatment of coronavirus disease 2019 (COVID-19). Using data from eight clinical trials, we describe a population pharmacokinetic (popPK) model of AZD7442 and show how modeling of "interim" data accelerated decision-making during the COVID-19 pandemic. The final model was a two-compartmental distribution model with first-order absorption and elimination, including standard allometric exponents for the effect of body weight on clearance and volume. Other covariates included were as follows: sex, age >65 years, body mass index ≥30 kg/m2, and diabetes on absorption rate; diabetes on clearance; Black race on central volume; and intramuscular (IM) injection site on bioavailability. Simulations indicated that IM injection site and body weight had > 20% effects on AZD7442 exposure, but no covariates were considered to have a clinically relevant impact requiring dose adjustment. The pharmacokinetics of AZD7442, cilgavimab, and tixagevimab were comparable and followed linear kinetics with extended half-lives (median 78.6 days for AZD7442), affording prolonged protection against susceptible SARS-CoV-2 variants. Comparison of popPK simulations based on "interim data" with a target concentration based on 80% viral inhibition and assuming 1.81% partitioning into the nasal lining fluid supported a decision to double the PrEP dosage from 300 mg to 600 mg to prolong protection against Omicron variants. Serum AZD7442 concentrations in adolescents weighing 40-95 kg were predicted to be only marginally different from those observed in adults, supporting authorization for use in adolescents before clinical data were available. In these cases, popPK modeling enabled accelerated clinical decision-making.

EP300 promotes lung cancer cell proliferation by regulating the oncogenic transcription of Hippo-YAP signaling pathway.

The transcriptional activation function of YAP in cancer development has been widely studied. However, the underlying regulatory mechanisms remain largely unknown. In this study, we found that EP300, one histone acetyltransferase, interacted with YAP and was recruited into the phase separated condensates of YAP. Transcriptomic analysis revealed substantial alterations in gene expression upon EP300 depletion, with downregulated genes associated with cancer progression and Hippo-YAP pathway. Notably, disruption of EP300 inhibited the transcriptional activation of YAP and reduced the binding of H3K27ac on YAP target oncogenes in Hippo pathway. Moreover, depletion of EP300 effectively inhibited YAP-driven tumor growth. Taken together, these results indicate that EP300 contributes to lung cancer progression by promoting the oncogenic transcription of YAP through H3K27ac, which suggests that YAP-EP300 axis may be potential therapeutic targets for lung cancer treatment.

The rice blast fungus SR protein 1 regulates alternative splicing with unique mechanisms.

Serine/arginine-rich (SR) proteins are well known as splicing factors in humans, model animals and plants. However, they are largely unknown in regulating pre-mRNA splicing of filamentous fungi. Here we report that the SR protein MoSrp1 enhances and suppresses alternative splicing in a model fungal plant pathogen Magnaporthe oryzae. Deletion of MoSRP1 caused multiple defects, including reduced virulence and thousands of aberrant alternative splicing events in mycelia, most of which were suppressed or enhanced intron splicing. A GUAG consensus bound by MoSrp1 was identified in more than 94% of the intron or/and proximate exons having the aberrant splicing. The dual functions of regulating alternative splicing of MoSrp1 were exemplified in enhancing and suppressing the consensus-mediated efficient splicing of the introns in MoATF1 and MoMTP1, respectively, which both were important for mycelial growth, conidiation, and virulence. Interestingly, MoSrp1 had a conserved sumoylation site that was essential to nuclear localization and enhancing GUAG binding. Further, we showed that MoSrp1 interacted with a splicing factor and two components of the exon-joining complex via its N-terminal RNA recognition domain, which was required to regulate mycelial growth, development and virulence. In contrast, the C-terminus was important only for virulence and stress responses but not for mycelial growth and development. In addition, only orthologues from Pezizomycotina species could completely rescue defects of the deletion mutants. This study reveals that the fungal conserved SR protein Srp1 regulates alternative splicing in a unique manner.

Selective Chemical Labeling Strategy for Oligonucleotides Determination: A First Application to Full-Range Profiling of Transfer RNA Modifications.

To date, the extremely high polarity and poor signal intensity of macromolecular nucleic acids are greatly impeding the progress of mass spectrometry technology in the quality control of nucleic acid drugs and the characterization of DNA oxidation and RNA modifications. We recently described a general N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) labeling method for oligonucleotide determination and applied it to the full-range profiling of tRNA in vitro and in vivo studies for the first time. The primary advantages of this method include strong retention, no observable byproducts, predictable and easily interpreted MS2 data, and the circumvention of instrument harmful reagents that were necessary in previous methods. Selective labeling of N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide to the terminal phosphate groups of oligonucleotides endows it broadly applicable for DNA/RNA profiling. Moreover, the improvement of sequence coverage was achieved in yeast tRNAphe(GAA) analysis owing to this method's good detection capability of 1-12 nucleotides in length. We also extended this strategy to determine the abundance of modified bases and discover new modifications via digesting RNA into single-nucleotide products, promoting the comprehensive mapping of RNA. The easy availability of derivatization reagent and the simple, rapid one-step reaction render it easy to operate for researchers. When applied in characterizing tRNAs in HepG2 cells and rats with nonalcoholic fatty liver disease, a fragment of U[m1G][m2G], specific for tRNAAsn(QUU) in cells, was significantly upregulated, indicating a possible clue to nonalcoholic fatty liver disease pathogenesis.

Spatial distribution and comparative analysis of Aconitum alkaloids in Fuzi using DESI-MSI and UHPLC-QTOF-MS.

Aconitum L. poisoning is a major type of poisoning caused by herbal medicines in many countries. However, despite its toxicity, Aconitum L. is still used because of its therapeutic value. Fuzi, the lateral root of Aconitum L., is one of the most important pharmacological parts. It is necessary for rational medication to figure out the types and contents of toxic Aconitum alkaloids (AAs) in Fuzi and its processed products. The present study aims to investigate the spatial distribution of toxic AAs in Fuzi and the quantification of AAs in various processing products through mass spectrometry methods. In this study, desorption electrospray ionization mass spectrometry imaging (DESI-MSI) was used to directly image the sections of raw Fuzi. The results showed a high content of diester alkaloids (DAs) and a relatively uniform distribution in the sections, while the content of monoester alkaloids (MAs) was low and uneven in the sections, distributed in the cortex, epidermis, vascular column, and other parts of the tissues. The content of non-ester alkaloids (NAs) was relatively minimum, and most of the NAs were distributed in the vascular column and the tightly connected cortex of the tissue. To further investigate the difference between raw and processed Fuzi, 60 known compounds were identified using UHPLC-QTOF-MS. The total contents of alkaloids in 7 processed Fuzi were lower than that in Shengfupian (SFP). Paofupian (PFP), Paotianxiong (PTX), Paofupian (PFP*), Danfupian (DFP), and Shufupian (SFP*) were the least similar. Zhengfupian (ZFP) and Chaofupian (CFP) had significantly reduced toxicity and increased efficacy compared with other processed products because the contents of active alkaloids in other processed products were also reduced. Understanding the distribution of metabolites and the composition changes after processing can guide users and herbal manufacturers to carefully choose the relatively safe and better therapeutic species of Fuzi. The information gathered from this study can contribute towards the improved and effective management of therapeutically important, nonetheless toxic, drugs such as Aconitum L.

Application value of Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol in patients with resistant ovary syndrome.

BACKGROUND: Resistant ovarian syndrome(ROS) is a rare disease. It is difficult to diagnose and treat. Most of the literature reports on assisted pregnancy treatment for ROS patients are individual case reports. In this paper, the ovulation stimulation protocol and assisted pregnancy process of ROS infertile patients in our reproductive center were summarized and analyzed to provide information and support for the clinical treatment of ROS patients. METHODS: From January 2017 to March 2022, assisted reproductive technology treatments and clinical characteristics parameters of six patients with ROS were retrospectively reviewed. Based on controlled ovarian stimulation protocols, these stimulation cycles were separated into four groups: Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol (EFLL) group (n = 6), Progestin Primed Ovarian Stimulation(PPOS) protocol group (n = 5), mild-stimulation protocol group (n = 2), and Natural cycle protocol group (n = 3). RESULTS: A total of 16 cycles of ovulation stimulation were carried out in 6 patients with ROS. A total of 19 oocytes were retrieved, as well as 13 MII oocytes, 11 two pronuclear(2PN) fertilized embryos, and 8 excellent embryos. The oocytes acquisition rate was 50% and the fertilization rate of 2PN was 57.9%, and the excellent embryo rate was 72.7%. The EFLL protocol obtained 17 oocytes, 12 MII oocytes, 11 2PN fertilized embryos, and 8 excellent embryos; the mild-stimulation protocol obtained 1 oocyte; the Natural cycle protocol obtained 1 oocyte, and oocytes were not matured after in vitro maturation (IVM); the PPOS protocol obtained no oocytes. Compared with three other protocols, The fertilization rate of 2PN (64.7%) and excellent embryo rate (72.7%) in the EFLL protocol were higher than those of other protocols(0%). Two fresh cycle embryo transfers resulted in live births, while two frozen-thawed embryo transfer cycles resulted in one live birth and one clinical pregnancy using the EFLL protocol. CONCLUSION: Although the current study is based on a small sample of participants, the findings suggest that the EFLL protocol can be employed for ovarian stimulation and may result in a live birth in ROS patients.

The protective effect of inhibiting mitochondrial fission on the juvenile rat brain following PTZ kindling through inhibiting the BCL2L13/LC3 mitophagy pathway.

Maintaining the balance of mitochondrial fission and mitochondrial autophagy on seizures is helpful to find a solution to control seizures and reduce brain injuries. The present study is to investigate the protective effect of inhibiting mitochondrial fission on brain injury in juvenile rat epilepsy induced by pentatetrazol (PTZ) by inhibiting the BCL2L13/LC3-mediated mitophagy pathway. PTZ was injected (40 mg/kg) to induce kindling once every other day, for a total of 15 times. In the PTZ + DMSO (DMSO), PTZ + Mdivi-1 (Mdivi-1), and PTZ + WY14643 (WY14643) groups, rats were pretreated with DMSO, Mdivi-1 and WY14643 for half an hour prior to PTZ injection. The seizure attacks of young rats were observed for 30 min after model establishment. The Morris water maze (MWM) was used to test the cognition of experimental rats. After the test, the numbers of NeuN(+) neurons and GFAP(+) astrocytes were observed and counted by immunofluorescence (IF). The protein expression levels of Drp1, BCL2L13, LC3 and caspase 3 in the hippocampus of young rats were detected by immunohistochemistry (IHC) and Western blotting (WB). Compared with the PTZ and DMSO groups, the seizure latency in the Mdivi-1 group was longer (P < 0.01), and the severity degree and frequency of seizures were lower (P < 0.01). The MWM test showed that the incubation periods of crossing the platform in the Mdivi-1 group was significantly shorter. The number of platform crossings, the platform stay time, and the ratio of residence time/total stay time were significantly increased in the Mdivi-1 group (P < 0.01). The IF results showed that the number of NeuN(+) neurons in the Mdivi-1 group was greater, while the number of GFAP(+) astrocytes was lower. IHC and WB showed that the average optical density (AOD) and relative protein expression levels of Drp1, BCL2L13, LC3 and caspase 3 in the hippocampi of rats in the Mdivi-1 group were higher (P < 0.05). The above results in the WY14643 group were opposite to those in the Mdivi-1 group. Inhibition of mitochondrial fission could reduce seizure attacks, protect injured neurons, and improve cognition following PTZ-induced epilepsy by inhibiting mitochondrial autophagy mediated by the BCL2L13/LC3 mitophagy pathway.

Global Path Planning of Unmanned Surface Vehicle Based on Improved A-Star Algorithm.

To make unmanned surface vehicles that are better applied to the field of environmental monitoring in inland rivers, reservoirs, or coasts, we propose a global path-planning algorithm based on the improved A-star algorithm. The path search is carried out using the raster method for environment modeling and the 8-neighborhood search method: a bidirectional search strategy and an evaluation function improvement method are used to reduce the total number of traversing nodes; the planned path is smoothed to remove the inflection points and solve the path folding problem. The simulation results reveal that the improved A-star algorithm is more efficient in path planning, with fewer inflection points and traversing nodes, and the smoothed paths are more to meet the actual navigation demands of unmanned surface vehicles than the conventional A-star algorithm.

CHRAC1 promotes human lung cancer growth through regulating YAP transcriptional activity.

ATP-dependent chromatin remodeling complexes regulate chromatin structure and play important roles in gene expression, differentiation, development and cancer progression. Dysregulation in the subunits of the complexes often has been found in different cancers, but how they influence cancer initiation and progression is not fully understood. Here, we show that Chromatin Accessibility Complex Subunit 1 (CHRAC1), the accessory subunit of chromatin remodeling complex, is highly expressed in lung cancer tissues, which correlates with poor prognosis in lung cancer patients. CHRAC1 overexpression promotes lung cancer cell proliferation and migration in vitro and tumor growth in genetically engineered KrasG12D.LSL lung adenocarcinoma mouse model. Consistent with this, CHRAC1 silencing inhibits cell proliferation and migration in lung cancer cells and suppresses tumor growth in xenograft mouse model. Further, CHRAC1 binds to the transcription coactivator Yes-associated protein (YAP), enhances the transcription of downstream target oncogenes in Hippo pathway and thus promotes the tumor growth. Together, our study defines a critical role of CHRAC1 in promoting YAP transcriptional activity and lung cancer tumorigenesis, which makes it a potential target for lung cancer.

Prognostic significance and immune characteristics of CMTM4 in hepatocellular carcinoma.

BACKGROUND: Previous study has shown that chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family member 4 (CMTM4) can bind and maintain programmed cell death ligand 1 (PD-L1) expression to promote tumor progression by alleviating the suppression of tumor-specific T cell activity, suggesting its potential role in tumor immunotherapy. However, the role of CMTM4 in tumor immunity has not been well clarified, especially in hepatocellular carcinoma (HCC). METHODS: The protein expression of CMTM4/PD-L1/CD4/CD8 was detected by immunohistochemistry (IHC) detection in 90 cases of HCC tissues. The mRNA expression profiles and related prognosis data were obtained from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC). Two immune therapy cohorts were from Imvigor210 and GSE176307. RESULTS: Though the single protein expression of CMTM4, PD-L1, CD4 or CD8 in HCC tissues by IHC detection didn't show a significant relationship with the prognosis of HCC patients, we found that high co-expression of CMTM4/PD-L1/CD4 showed a good prognosis of HCC patients. Further Timer 2.0 analysis identified that HCC patients with high expression of CMTM4/PD-L1 and high infiltration of CD4+ T cells had a better overall survival than those with low infiltration of CD4+ T cells. Moreover, a series of bioinformatics analyses revealed that CMTM4-related genes posed important effects on prognosis and immunity in HCC patients, and CMTM4 had a positive correlation with infiltration of CD4+ and CD8+ T cells in HCC. At last, we used two immunotherapy cohorts to verify that the combination of CMTM4 with PD-L1 could improve the prognosis of tumor patients underwent immunotherapy. CONCLUSIONS: CMTM4 and PD-L1 co-expression with T cell infiltration shows prognostic significance in HCC, suggesting combined effect from multiple proteins should be considered in HCC treatment.

Atomic zinc sites with hierarchical porous carbon for high-throughput chemical screening with high loading capacity and stability.

Alzheimer's disease (AD) is a neurodegenerative disease associated with aging, and the number of people affected is rapidly increasing. Abnormally hyperphosphorylated tau filaments and extracellular deposits of amyloid ß-peptides (Aß) fibrils are two important pathological hallmarks of AD. Currently, stopping the production of Aß and blocking its aggregation is the main strategy for the treatment of AD. Turmeric is effective in treating neurodegenerative diseases, but there is no effective way to identify active compounds from their complicated chemical compositions. Instead of using conventional extraction and separation methods with low efficiency and time-consuming, our group tried to use atomic materials in high-throughput chemical screening due to their structural characteristics and the unique advantages of surface atomic. Herein, a novel atomic zinc sites with hierarchical porous carbon (Zn-HPC) was synthesized to quickly screen potential inhibitors of Aß aggregation in turmeric. As-combined Aß@Zn-HPC demonstrates superior storage stability and high selectivity, outperforming the most reported supporters for ligand fishing. Five compounds with strong affinity on Aß@Zn-HPC were selected by high-performance liquid chromatography-hybrid linear ion trap/orbitrap mass spectrometer after incubation with turmeric extract. Finally, it was shown that curcumin and bisdemethoxycurcumin can inhibit Aß aggregation by using thioflavin-T fluorescence assay and biolayer interferometry. A new application for the accurate identification of Aß aggregation inhibitors from turmeric were developed based on the active compounds possessing binding affinity to Aß to inhibit its aggregation. The developed method could provide a promising tool for efficient drug discovery from natural product resources.

Detection of Microcystin-LR in the Cells and Natural Lake Water Samples by A Unique Fluorescence-Based Method.

Microcystin-LR (MC-LR) is widely distributed in natural lakes and could strongly inhibit protein phosphatase activity; it is also a potent liver tumor promoter. Over the last two decades, tremendous efforts have been devoted to enhance the detection of MC-LR in water samples. However, the traditional method is complex and costly, and achieving the fast, sensitive, and accurate determination of MC-LR in the cells and natural lakes by using fluorescence signal changes is fairly difficult. Our work explores novel fluorescent probes that are capable of concurrently analyzing and detecting MC-LR in the cells and water. In this study, we introduce, for the first time, 5-AF and 6-AF as small-molecule fluorescent probes suitable for MC-LR detection in the cells and water samples based on fluorescence signal changes. We titrated 5-AF and 6-AF with MC-LR in pure water, scanned the fluorescence of the sample, and then obtained the equation the fluorescence intensity versus MC-LR concentration curve. MC-LR in lake water samples was crudely purified, and then 5-AF was added to measure its fluorescence peak. The fluorescence intensity of 5-AF is significantly enhanced with increasing MC-LR concentration. This enhancement trend is stable and could be mathematically modeled. We also comprehensively analyzed the mechanism and recognition principle of the probe response to MC-LR in natural lake water. Moreover, we believe that 5-AF may be capable of detecting exogenous MC-LR in cells. The results of this study reveal that these unique fluorescent probes may be applied to construct near-infrared fluorescent probes that could detect MC-LR levels in vivo.

Exploring the direct effects of microcystin-LR on DNA via using cross-technical means.

Microcystin-leucine arginine (MC-LR) is the most toxic and abundant microcystin produced by cyanobacteria. Previous studies have demonstrated that MC-LR can lead to DNA damage by increasing intracellular reactive oxygen species content to induce oxidative stress. However, the direct effect of MC-LR on DNA has not been fully described. In this study, the direct effect of MC-LR on DNA was explored by using spectral analysis and molecular biology technology. First, the fluorescent probe Bptp-R2 was developed to monitor different types of DNA and explore the direct interaction between DNA and MC-LR. The significant differences in the fluorescence of probe-plasmid DNA and probe-ds DNA at various MC-LR concentrations (0, 5, 10, 20, and 30 µmol/L) and MC-LR exposure times (0, 6, 12, and 24 h) showed that the direct interaction between DNA and MC-LR was significant (P ≤ 0.01). Gel electrophoresis demonstrated that the direct interaction between DNA and MC-LR cannot cause DNA strand breaks or change DNA configuration. Then, PCR experiments revealed that the direct interaction between DNA and MC-LR cannot affect DNA replication in a PCR system (P ≤ 0.01). This study discovered that the effects of MC-LR on DNA originate mainly from the secondary effects of MC-LR rather than from the direct interaction between DNA and MC-LR.

Magnetic Fluorescent Quantum Dots Nanocomposites in Food Contaminants Analysis: Current Challenges and Opportunities.

The presence of food contaminants can cause foodborne illnesses, posing a severe threat to human health. Therefore, a rapid, sensitive, and convenient method for monitoring food contaminants is eagerly needed. The complex matrix interferences of food samples and poor performance of existing sensing probes bring significant challenges to improving detection performances. Nanocomposites with multifunctional features provide a solution to these problems. The combination of the superior characteristics of magnetic nanoparticles (MNPs) and quantum dots (QDs) to fabricate magnetic fluorescent quantum dots (MNPs@QDs) nanocomposites are regarded as an ideal multifunctional probe for food contaminants analysis. The high-efficiency pretreatment and rapid fluorescence detection are concurrently integrated into one sensing platform using MNPs@QDs nanocomposites. In this review, the contemporary synthetic strategies to fabricate MNPs@QDs, including hetero-crystalline growth, template embedding, layer-by-layer assembly, microemulsion technique, and one-pot method, are described in detail, and their advantages and limitations are discussed. The recent advances of MNPs@QDs nanocomposites in detecting metal ions, foodborne pathogens, toxins, pesticides, antibiotics, and illegal additives are comprehensively introduced from the perspectives of modes and detection performances. The review ends with current challenges and opportunities in practical applications and prospects in food contaminants analysis, aiming to promote the enthusiasm for multifunctional sensing platform research.

Antitumor Mechanism of Hydroxycamptothecin via the Metabolic Perturbation of Ribonucleotide and Deoxyribonucleotide in Human Colorectal Carcinoma Cells.

Hydroxycamptothecin (SN38) is a natural plant extract isolated from Camptotheca acuminate. It has a broad spectrum of anticancer activity through inhibition of DNA topoisomerase I, which could affect DNA synthesis and lead to DNA damage. Thus, the action of SN38 against cancers could inevitably affect endogenous levels of ribonucleotide (RNs) and deoxyribonucleotide (dRNs) that play critical roles in many biological processes, especially in DNA synthesis and repair. However, the exact impact of SN38 on RNs and dRNs is yet to be fully elucidated. In this study, we evaluated the anticancer effect and associated mechanism of SN38 in human colorectal carcinoma HCT 116 cells. As a result, SN38 could decrease the cell viability and induce DNA damage in a concentration-dependent manner. Furthermore, cell cycle arrest and intracellular nucleotide metabolism were perturbed due to DNA damage response, of which ATP, UTP, dATP, and TTP may be the critical metabolites during the whole process. Combined with the expression of deoxyribonucleoside triphosphates synthesis enzymes, our results demonstrated that the alteration and imbalance of deoxyribonucleoside triphosphates caused by SN38 was mainly due to the de novo nucleotide synthesis at 24 h, and subsequently the salvage pathways at 48 h. The unique features of SN38 suggested that it might be recommended as an effective supplementary drug with an anticancer effect.

Okadaic acid promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells by inhibiting protein phosphatase 2A.

As a specific inhibitor of serine/threonine protein phosphatases, okadaic acid (OA) has been found to be a tumor promoter. However, whether OA plays a role in metastasis of hepatocellular carcinoma (HCC) has not been well elucidated. In this study, Hep3B and HepG2 cells were treated with different doses of OA and the cell viability was determined by CCK8 test. As a result, Hep3B and HepG2 cells showed no obvious cytotoxicity after OA treatment below 20 or 25 nM for 12 or 24 hours. However, wound healing, invasion, and migration abilities of HCC cells were significantly enhanced in the OA-treated groups than those of the control group (P < .05), measured by cell scratching and BD transwell assays. Moreover, we found that the expression of epithelial-mesenchymal transition (EMT)-related key factors was changed upon OA treatment in a dose-dependent manner. In addition, the activity of protein phosphatase 2A (PP2A) in OA-treated cells was also decreased significantly compared with the control cells (P < .05). Interfering of PP2A subunit A or C caused a similar expression change of EMT-related key factors as the OA treatment in HCC cells. Our results suggest that OA promotes the EMT process of HCC cells by inhibiting the activity of PP2A.

Detection of p53 mutation and serum monitoring alert caused by Marek's disease virus in poultry.

BACKGROUND: Marek's disease (MD) is a chicken neoplastic disease, which brings huge economic losses to the global poultry industry. The wild type p53, a tumor suppressor gene, plays a key role in blocking cell cycle, promoting apoptosis, and maintaining the stability of the genome. However, the mutant p53 losses its tumor inhibitory role and become an oncogene when a mutation has happened. RESULTS: The mutation rate of p53 was 60% in the experimentally and naturally infected chickens. The mutations included point-mutations and deletions, and mostly located in the DNA-binding domain. The mutated p53 was expressed in various tumor tissues in an infected chicken. The mutant P53 proteins were notably accumulated in the cytoplasm due to the loss in the function of nuclear localization. Unlike the study on human cancer, the concentrations of P53 in the serums of MD infected chicken were significantly lower than the control group. CONCLUSIONS: The p53 mutations were apparent in the development of MD. P53 and P53 antibody level in serum could be a useful marker in the diagnosis and surveillance of MD.

High level of visfatin and the activation of Akt and ERK1/2 signaling pathways are associated with endometrium malignant transformation in polycystic ovary syndrome.

This study aimed to assess the clinicopathological significance of serum levels and endometrium tissue expression of visfatin in polycystic ovary syndrome (PCOS) patients. A total of 80 PCOS patients and 80 matching controls were included in this study. We analyzed the relationship between the expression of visfatin in endometrium and clinicopathological characteristics in PCOS patients. The correlation between the expression of visfatin and p-Akt, Akt, p-ERK1/2, and ERK1/2 in PCOS tissues was evaluated as well. Visfatin expression in PCOS endometrial tissues were significantly higher than those in controls (p = .001). The expression of phosphorylation of Akt and ERK1/2 were significantly higher in PCOS endometrium tissues compared to controls (p < .05). Moreover, a high expression of tissue visfatin in PCOS tissues was positively correlated with the expression of p-Akt (p = .015), and p-ERK1/2 (p = .013). Western blotting revealed that protein expression of visfatin in PCOS patients with endometrial hyperplasia and cancer was higher than that in patients with normal endometrium tissues, and the difference was statistically significant (p = .027). The expression of p-Akt (p = .018) and p-ERK1/2 (p = .035) in PCOS patients with endometrial hyperplasia and cancer was significantly higher than that in patients with normal endometrium tissues. Visfatin may be a potential biomarker for endometrial malignant transformation in PCOS patients.