Detection and surveillance of circulating tumor cells in osteosarcoma for predicting therapy response and prognosis

Objective:Osteosarcoma(OS)is an aggressive,highly metastatic,relatively drug-resistant bone tumor with poor long-term survival rates.The presence and persistence of circulating tumor cells(CTCs)in the peripheral blood are believed to be associated with treatment inefficiency and distant metastases.A blood-based CTC test is thus greatly needed for monitoring disease progression and predicting clinical outcomes.However,traditional methods cannot detect CTCs from tumors of mesenchymal origin such as OS,and research on CTC detection in mesenchymal tumors has been hindered for years.Methods:In this study,we developed a CTC test based on hexokinase 2,a metabolic function-associated marker,for the detection and surveillance of OS CTCs,and subsequently explored its clinical value.Twelve patients with OS were enrolled as the training cohort for serial CTC tests.Dynamic CTC counting,in combination with therapy evaluation and post-treatment follow-up,was used to establish a model for predicting post-chemotherapy evaluation and disease-free survival,and the model was further validated with a cohort of 8 patients with OS.Results:Two dynamic CTC number patterns were identified,and the resulting predictive model exhibited 92%consistency with the clinical outcomes.This model suggested that a single CTC test has similar predictive power to serial CTC analysis.In the validation cohort,the single CTC test exhibited 100%and 87.5%consistency with therapy response and disease-free survival,respectively.Conclusions:Our non-invasive test for detection and surveillance of CTCs enables accurate prediction of therapy efficiency and prognosis,and may be clinically valuable for avoiding inefficient therapy and prolonging survival.

Adsorptive carbon-based materials for biomedical applications

Adsorption or enrichment has been an indispensable and important measure in biomedical engineering since it is promising in diagnosis and treatment of complex diseases.The ongoing development in this arena starves for exploration of outstanding adsorptive materials.As an excellent candidate for adsorption or enrichment carriers,carbon-based material has demonstrated unique superiority in biomedical arena owing to its integrated charac-teristics.Herein,we review the lasted advance in adsorptive carbon-based materials for biomedical application with emphasis on carbon nanotubes(CNTs)-based,graphene-based,and biomass/polymer-based ones.We begin with the classification of different carbon-based materials and elaborate the respective preparation approaches that are utilized to realize optimized microstructure and physicochemical property.Afterwards,we introduce the different applications of carbon-based materials in biomedical arena,including blood purification,enrichment of glycopeptide and phosphopeptide,and breath analysis.Finally,we present a concise summary and give an outlook of this arena.

Living Materials for Regenerative Medicine

Regenerative medicine has been attracting tremendous attention during the past few decades because it is promising in overcoming the limitations of donor shortage and immune complications in direct transplantations.The ongoing progress in this field calls for the rapid growth of living materials,which consist of live biological agents and can be designed together with synthetic materials to meet the application demands of regenerative medicine.In this review,we present a summary of the state-of-the-art progress of living materials that are applied in regenerative medicine.We first introduce the advanced engineering approaches that are employed to prepare living materials containing live cells,typically including genetic engineering,cell coating,microfluidics,and bioprinting,etc.Afterwards,we enumerate different application aspects of living materials in regenerative medicine,including tissue scaffold,cell therapy,tissue models,and so on.Finally,we give a concise conclusion and provide a perspective of this field.

PMN-MDSCs modulated by CCL20 from cancer cells promoted breast cancer cell stemness through CXCL2-CXCR2 pathway

Our previous studies have showed that C-C motif chemokine ligand 20(CCL20)advanced tumor progression and enhanced the chemoresistance of cancer cells by positively regulating breast cancer stem cell(BCSC)self-renewal.However,it is unclear whether CCL20 affects breast cancer progression by remodeling the tumor microenvironment(TME).Here,we observed that polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)were remarkably enriched in TME of CCL20-overexpressing cancer cell orthotopic allograft tumors.Mechanistically,CCL20 activated the differentiation of granulocyte-monocyte progenitors(GMPs)via its receptor C-C motif chemokine receptor 6(CCR6)leading to the PMN-MDSC expansion.PMN-MDSCs from CCL20-overexpressing cell orthotopic allograft tumors(CCL20-modulated PMN-MDSCs)secreted amounts of C-X-C motif chemokine ligand 2(CXCL2)and increased ALDH+BCSCs via activating CXCR2/NOTCH1/HEY1 signaling pathway.Furthermore,C-X-C motif chemokine receptor 2(CXCR2)antagonist SB225002 enhanced the docetaxel(DTX)effects on tumor growth by decreasing BCSCs in CCL20high-expressing tumors.These findings elucidated how CCL20 modulated the TME to promote cancer development,indicating a new therapeutic strategy by interfering with the interaction between PMN-MDSCs and BCSCs in breast cancer,especially in CCL20high-expressing breast cancer.

Cryo-shocked cancer cell microgels for tumor postoperative combination immunotherapy and tissue regeneration

Prevention of recurrence/metastasis and tissue regeneration are critical for post-surgery treatment of malignant tumors. Here, to address these needs, a novel type of microgel co-loading cryo-shocked cancer cells, immunoadjuvant, and immune checkpoint inhibitor is presented by microfluidic electrospray technology and liquid nitrogen treatment. Owing to the encapsulation of cryo-shocked cancer cells and immunoadjuvant, the microgels can recruit dendritic cells and activate them in situ, and evoke a robust immune response. Moreover, with the combination of the immune checkpoint inhibitor, the antitumor immune response is further enhanced by inhibiting the interaction of PD1 and PDL1. With this, the excellent anti-recurrence and anti-metastasis efficacy of the microgels are demonstrated in an orthotopic breast cancer mouse model. Besides, because of the excellent biocompatibility and appropriate degradation performance, the microgels can provide support for normal cell adhesion and growth, which is beneficial to tissue reconstruction. These properties indicate the great value of the cryo-shocked cancer cell microgels for efficient tumor postoperative combination immunotherapy and tissue regeneration.

DNA-Polyelectrolyte Composite Responsive Microparticles for Versatile Chemotherapeutics Cleaning

Drug therapy is among the most widely used methods in disease treatment.However,there remains a trade-off problem between drug dosage and toxicity.Blood purification by adsorption of excessive drugs during clinical treatment could be a solution for enhancing therapeutic efficacy while maintaining normal body function.Here,inspired by the intrinsic action mechanism of chemotherapeutic agents in targeting DNA in the cell nucleus,we present DNA-polyelectrolyte composite responsive microparticles for chemotherapeutics cleaning.The presence of DNA in the microparticles enabled the adsorption of multiple common chemotherapy drugs.Moreover,the microparticles are endowed with a porous structure and a photothermal-responsive ability,both of which contribute to improved adsorption by enhancing the contact of the microparticles with the drug solution.On the basis of that,the microparticles are integrated into a herringbone-structured microfluidic chip.The fluid mixing capacity and the enhanced drug cleaning efficiency of the microfluidic platform are validated on-chip.These results indicate the value of the DNA-polyelectrolyte composite responsive microparticles for drug capture and blood purification.We believe the microparticle-integrated microfluidic platform could provide a solution for settling the dosage-toxicity trade-off problems in chemotherapy.

Phosphorylation of NF2 at Serine-13 by MAP4K family kinases mediates pathological angiogenesis

Dear Editor,Angiogenesis is vital for the development and maintenance of functional organs,and also participates in diverse pathological processes,such as wound healing,oxygen tension,and tumorigenesis(Potente et al.,2011).Thus,understanding the molecular mechanisms responsible for angiogenesis has important clinical implications and may guide strategies for drug development.

Structural basis of INTAC-regulated transcription

DearEditor,Eukaryotic transcription by RNA polymerase I(Pol I)is a strictly regulated process that involves the interplay of numerous factors.Promoter-proximal pausing is a regulatory mechanism that connects transcription initiation and productive elongation in metazoans(Core and Adelman,2019).Pol II forms a paused elongation complex(PEC)through binding of two transcriptional regulation factors DSIF and NELF(Vos et al.,2018).Following the duration of pausing,Pol II either proceeds into productive elongation or undergoes promoter-proximal premature transcription termination(PTT)(Kamieniarz-Gdula and Proudfoot,2019),which plays a decisive role in determining transcriptional outputs.

Pollen-Inspired Photonic Barcodes with Prickly Surface for Multiplex Exosome Capturing and Screening

Exosomes,which play an important role in intercellular communication,are closely related to the pathogenesis of disease.However,their effective capture and multiplex screening are still challenging.Here,inspired by the unique structure of pollens,we present novel photonic crystal(PhC)barcodes with prickly surface by hydrothermal synthesis for multiplex exosome capturing and screening.These pollen-inspired PhC barcodes are imparted with extremely high specific surface area and excellent prickly surface nanostructures,which can improve the capture rate and detection sensitivity of exosomes.As the internal periodic structures are kept during the hydrothermal synthesis process,the pollen-inspired PhC barcodes exhibit obvious and stable structural colors for identification,which enables multiplex detection of exosomes.Thus,the pollen-inspired PhC barcodes can not only effectively capture and enrich cancer-related exosomes but also support multiplex screening of exosomes with high sensitivity.These features make the prickly PhC barcodes ideal for the analysis of exosomes in medical diagnosis.

Biallelic mutations in CDC20 cause female infertility characterized by abnormalities in oocyte maturation and early embryonic development

Dear Editor,Previously,the Mendelian phe no types in huma n oocyte maturation arrest,fertilization failure and early embryonic arrest,are largely underestimated.In recent years,"missing"Men delian phe no types and genes in these processes are beginning to be uncovered by us and others(Huang et al.,2014;Alazami et al..2015;Feng et al.,2016;Xu et al.,2016;Chen et al.,2017;Sang et al.,2019).However,the genetic basis for majority of patients resulting from abnormalities in these phe no types remains to be elucidated.

Tumor-derived neomorphic mutations in ASXL1 impairs the BAP1-ASXL1-FOXK1/K2 transcription network

Additional sex combs-like 1(ASXL1)interacts with BRCA1-associated protein 1(BAP1)deubiquitinase to oppose the polycomb repressive complex 1(PRC1)-mediated histone H2A ubiquitylation.Germline BAP1 mutations are found in a spectrum of human malignancies,while ASXL1 mutations recurrently occur in myeloid neoplasm and are associated with poor prognosis.Nearly all ASXL1 mutations are heterozygous frameshift or nonsense mutations in the middle or to a less extent the C-terminal region,resulting in the production of C-terminally truncated mutant ASXL1 proteins.How ASXL1 regulates specific target genes and how the C-terminal truncation of ASXL1 promotes leukemogen-esis are unclear.Here,we report that ASXL1 interacts with forkhead transcription factors FOXK1 and FOXK2 to regulate a subset of FOXK1/K2 target genes.We show that the C-terminally truncated mutant ASXL1 proteins are expressed at much higher levels than the wild-type protein in ASXL1 heterozygous leukemia cells,and lose the ability to interact with FOXK1/K2.Specific deletion of the mutant allele eliminates the expression of C-termi-nally truncated ASXL1 and increases the association of wild-type ASXL1 with BAP1,thereby restoring the expression of BAP1-ASXL1-FOXK1/K2 target genes,particularly those involved in glucose metabolism,oxygen sensing,and JAK-STAT3 signaling pathways.In addition to FOXK1/K2,we also identify other DNA-bind-ing transcription regulators including transcription factors(TFs)which interact with wild-type ASXL1,but not C-terminally truncated mutant.Our results suggest that ASXL1 mutations result in neomorphic alleles that contribute to leukemogenesis at least in part through dominantly inhibiting the wild-type ASXL1 from interacting with BAP1 and thereby impairing the function of ASXL1-BAP1-TF in regulating target genes and leukemia cell growth.

Acetylation promotes BCAT2 degradation to suppress BCAA catabolism and pancreatic cancer growth

Pancreatic ductal adenocarcinoma(PDAC)is well-known for inefficient early diagnosis,with most patients diagnosed at advanced stages.Increasing evidence indicates that elevated plasma levels of branched-chain amino acids(BCAAs)are associated with an increased risk of pancreatic cancer.Branched-chain amino acid transaminase 2(BCAT2)is an important enzyme in BCAA catabolism that reversibly catalyzes the initial step of BCAA degradation to branched-chain acyl-CoA.Here,we show that BCAT2 is acetylated at lysine 44(K44),an evolutionarily conserved residue.BCAT2 acetylation leads to its degradation through the ubiquitin–proteasome pathway and is stimulated in response to BCAA deprivation.cAMP-responsive element-binding(CREB)-binding protein(CBP)and SIRT4 are the acetyltransferase and deacetylase for BCAT2,respectively.CBP and SIRT4 bind to BCAT2 and control the K44 acetylation level in response to BCAA availability.More importantly,the K44R mutant promotes BCAA catabolism,cell proliferation,and pancreatic tumor growth.Collectively,the data from our study reveal a previously unknown regulatory mechanism of BCAT2 in PDAC and provide a potential therapeutic target for PDAC treatment.

蓬勃发展的微流控技术

Microfluidics refers to the technology that processes a small volume of fluids and exploits their specific properties at the sub-microliter scale in microchannels.When the fluid dimensions scale down to the microscale level,the specific surface area of the fluids increases,thus exhibiting behaviors divergent from those of the bulk fluids.Compared with the bulk systems,microfluidics technology offers many salient advantages.

Boston Ivy-Inspired Disc-Like Adhesive Microparticles for Drug Delivery

Microparticles with strong adherence are expected as efficient drug delivery vehicles.Herein,we presented an ingenious hydrogel microparticle recapitulating the adhesion mechanism of Boston ivy tendrils adhesive discs(AD)for durable drug delivery.The particles were achieved by replicating a silica colloidal crystal aggregates assembled in a droplet template after rapid solvent extraction.Due to their unique shape,the nanostructure,and the sticky hydrogel component,such novel microparticles exhibited prominent adhesive property to the wet tissue environment.It was demonstrated that the bioinspired microcarriers loading with dexamethasone had a good therapeutic effect for ulcerative colitis due to the strong adhesion ability for prolonging the maintenance of drug availability.These virtues make the biomimetic microparticles potentially ideal for many practical clinical applications,such as drug delivery,bioimaging,and biodiagnostics.

Pollens derived magnetic porous particles for adsorption of low-density lipoprotein from plasma

Adsorption of low-density lipoprotein from plasma is vital for the treatment of dyslipidemia.Appropriate adsorbent material for efficient and selective adsorption of low-density lipoprotein is highly desired.In this work,we developed pollens-derived magnetic porous particles as adsorbents for this purpose.The natural pollen grains were modified to obtain high surface porosity,a large inner cavity,magnet responsiveness,and specific wettability.The resultant particles exhibited satisfying performance in the adsorption of a series of oils and organic solvents out of water.Besides,the particles were directly utilized to the adsorption of low-density lipoprotein in plasma,which showed high selectivity,and achieved an outstanding adsorption capacity as high as 34.9%within 2 h.Moreover,their salient biocompatibility was demonstrated through simulative hemoperfusion experiments.These features,together with its abundant source and facile fabrication,makes the pollens-derived magnetic porous particles excellent candidate for low-density lipoprotein-apheresis and water treatment applications.

OGP: A Repository of Experimentally Characterized O-glycoproteins to Facilitate Studies on O-glycosylation

Numerous studies on cancers, biopharmaceuticals, and clinical trials have necessitated comprehensive and precise analysis of protein O-glycosylation. However, the lack of updated and convenient databases deters the storage of and reference to emerging O-glycoprotein data. To resolve this issue, an O-glycoprotein repository named OGP was established in this work.It was constructed with a collection of O-glycoprotein data from different sources. OGP contains 9354 O-glycosylation sites and 11,633 site-specific O-glycans mapping to 2133 O-glycoproteins, and it is the largest O-glycoprotein repository thus far.Based on the recorded O-glycosylation sites, an O-glycosylation site prediction tool was developed. Moreover, an OGP-based website is already available(http://www.oglyp.org/). The website comprises four specially designed and user-friendly modules:statistical analysis, database search, site prediction, and data submission. The first version of OGP repository and the website allow users to obtain various O-glycoprotein-related information, such as protein accession Nos., O-glycosylation sites,O-glycopeptide sequences, site-specific O-glycan structures, experimental methods, and potential O-glycosylation sites.O-glycosylation data mining can be performed efficiently on this website, which will greatly facilitate related studies. In addition, the database is accessible from OGP website(http://www.oglyp.org/download.php).

Structural Basis of RACK7 PHD Domain to Read a Pediatric Glioblastoma-Associated Histone Mutation H3.3G34R

Histone point mutations,including missense mutations on histone H3 at positions 27(K27M),34(G34R/V,G34W,G34L)and 36(K36M),were identified as potential cancer driver mutations.H3.3G34R/V mutations account for pediatric glioblastomas(GBM).RACK7(also known as ZMYND8,PRKCBP1)was recently reported to specifically bind H3.3G34R through its PHD(plant homedomain)domain(PHDRACK7)in vitro and in H3.3G34R pediatric glioblastoma cells,playing key roles in H3.3G34R-mediated gene transcription.Herein,we provided both biochemical and NMR structural evidences that PHDRACK7 recognized histone H3.3G34R mutant via a mechanism distinet from all other reported PHD domains.Except the reported residue D104,two new sites D108 and L121 of PHD^(RACK7) were found necessary for the interactions between PHD^(RACK7) and histone H3.3G34R peptide.Our results provided a potential molecular basis for pediatric GBM driven by the H3.3G34R mutation.