Continuation, reduction, or withdrawal of tofacitinib in patients with rheumatoid arthritis achieving sustained disease control: a multicenter, open-label, randomized controlled trial

BACKGROUND

Rheumatoid arthritis (RA), a chronic systemic autoimmune disease, is characterized by synovitis and progressive damage to the bone and cartilage of the joints, leading to disability and reduced quality of life. This study was a randomized clinical trial comparing the outcomes between withdrawal and dose reduction of tofacitinib in patients with RA who achieved sustained disease control.

METHODS

The study was designed as a multicenter, open-label, randomized controlled trial. Eligible patients who were taking tofacitinib (5 mg twice daily) and had achieved sustained RA remission or low disease activity (disease activity score in 28 joints [DAS28] ≤3.2) for at least 3 months were enrolled at six centers in Shanghai, China. Patients were randomly assigned (1:1:1) to one of three treatment groups: continuation of tofacitinib (5 mg twice daily); reduction in tofacitinib dose (5 mg daily); and withdrawal of tofacitinib. Efficacy and safety were assessed up to 6 months.

RESULTS

Overall, 122 eligible patients were enrolled, with 41 in the continuation group, 42 in the dose-reduction group, and 39 in the withdrawal group. After 6 months, the percentage of patients with a DAS28-erythrocyte sedimentation rate (ESR) of <3.2 was significantly lower in the withdrawal group than that in the reduction and continuation groups (20.5%, 64.3%, and 95.1%, respectively; P  < 0.0001 for both comparisons). The average flare-free time was 5.8 months for the continuation group, 4.7 months for the dose reduction group, and 2.4 months for the withdrawal group.

CONCLUSION

Withdrawal of tofacitinib in patients with RA with stable disease control resulted in a rapid and significant loss of efficacy, while standard or reduced doses of tofacitinib maintained a favorable state.

TRIAL REGISTRATION

Chictr.org, ChiCTR2000039799.

Eu3+ Single-Doped Phosphor with Antithermal Quenching Behavior and Multicolor-Tunable Properties for Luminescence Thermometry

To date, non-contact luminescence thermometry methods based on fluorescence intensity ratio (FIR) technology have been studied extensively. However, designing phosphors with high relative sensitivity (S_r) has become a research hotspot. In this work, Eu³⁺ single-doped Ca₂Sb₂O₇:Eu³⁺ phosphors with a high S_r value for dual-emitting-center luminescence thermometry are developed and proposed. The anti-thermal quenching behavior of Eu³⁺ originating from the energy transfer (ET) of host → Eu³⁺ is found and proved in the designed phosphors. Interestingly, adjustable color emission from blue to orange can be achieved. Surprisingly, the degree of the anti-thermal quenching behavior of Eu³⁺ gradually reduces from 240 to 127% as the Eu³⁺ doping content increases from 0.005 to 0.05 mol, attributed to most Eu³⁺ being located in the low symmetrical [Ca1O₈] dodecahedral site. According to the differentiable responses of the host and Eu³⁺ to temperature, the maximal S_r value reaches 3.369% K^-1 (383 K). Moreover, the ambient temperature can be intuitively predicted by observing the emitting color. Owing to the excellent performance in optical thermometry, color-tunable properties, and outstanding acid and alkali resistance for polydimethylsiloxane (PDMS) films, the developed Eu³⁺ single-doped Ca₂Sb₂O₇:Eu³⁺ phosphors are expected to be prospective candidates in luminescence thermometers and LED devices in various conditions.

MaskID: An effective deep-learning-based algorithm for dense rebar counting

As a dense instance segmentation problem, rebar counting in a complex environment such as rebar yard and rebar transpotation has received significant attention in both academic and industrial contexts. Traditional counting approaches, such as manual counting and machine vision-based algorithms, are often inefficient or inaccurate since rebars with varied sizes and shapes are stacked overlapping, rebar image is not clear for complex light condition such as dawn, night and strong light, and other environmental noises exist in rebar image; thus, they no longer fulfil the requirements of modern automation. This paper proposes MaskID, an innovative counting method based on deep learning and heuristic strategies. First, an improved version of the Mask region-based convolutional neural network (Mask R-CNN) was designed to obtain the segmentation results through splitting and rescaling so as to capture more detail in a large-scale rebar image. Then, a series of intelligent denoising strategies corresponding to aspect ratio of recognized box, overlapping recognized objects, object distribution and environmental noise, were applied to improve the segmentation results. The performance of the proposed method was evaluated on open-competition and test-platform datasets. The F1-score was found to be over 0.99 on all datasets. The experimental results demonstrate that the proposed method is effective for dense rebar counting and significantly outperforms existing state-of-the-art methods.

Immune diversity in lophotrochozoans, with a focus on recognition and effector systems

Lophotrochozoa is one of the most species-rich but immunologically poorly explored phyla. Although lack of acquired response in a narrow sense, lophotrochozoans possess various genetic mechanisms that enhance the diversity and specificity of innate immune system. Here, we review the recent advances of comparative immunology studies in lophotrochozoans with focus on immune recognition and effector systems. Haemocytes and coelomocytes are general important yet understudied player. Comparative genomics studies suggest expansion and functional divergence of lophotrochozoan immune reorganization systems is not as "homogeneous and simple" as we thought including the large-scale expansion and molecular divergence of pattern recognition receptors (PRRs) (TLRs, RLRs, lectins, etc.) and signaling adapters (MyD88s etc.), significant domain recombination of immune receptors (RLR, NLRs, lectins, etc.), extensive somatic recombination of fibrinogenrelated proteins (FREPs) in snails. Furthermore, there are repeatedly identified molecular mechanisms that generate immune effector diversity, including high polymorphism of antimicrobial peptides and proteins (AMPs), reactive oxygen and nitrogen species (RONS) and cytokines. Finally, we argue that the next generation omics tools and the recently emerged genome editing technicism will revolutionize our understanding of innate immune system in a comparative immunology perspective.

Wolfberry enhanced the abundance of Akkermansia muciniphila by YAP1 in mice with acetaminophen-induced liver injury

Drug-induced liver injury (DILI) by acetaminophen (APAP) was one of the most challenging liver diseases. Wolfberry (Lycium barbarum L.), a traditional Chinese medicinal material and food supplement, has a potential effect on increasing the abundance of Akkermansia muciniphila (A. muciniphila) in mice colons. However, the effect and mechanism of wolfberry remain unclear in APAP-induced DILI. In this study, wolfberry promoted the proliferation of activated-A. muciniphila in vitro and in vivo. For the first time, we detected that the activated-A. muciniphila but not the killed-A. muciniphila increased the expression level of Yes-associated protein 1 (YAP1) in the liver and alleviated liver injury in APAP-induced DILI mice. Mechanically, A. muciniphila improved the intestinal mucosal barrier and reduced lipopolysaccharide (LPS) content in the liver, leading to the increased expression level of YAP1. Furthermore, wolfberry increased the A. muciniphila abundance in the colon and YAP1 expression in the liver from APAP-induced DILI mice, which promoted the recovery of APAP-induced liver injury. Meanwhile, wolfberry combination with A. muciniphila synergistically increased AKK abundance and YAP1 expression in the liver. Our research provides an innovative strategy to improve DILI.

Dihydroartemisinin inhibited the Warburg effect through YAP1/SLC2A1 pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) was the third most common cause of cancer death. But it has only limited therapeutic options, aggressive nature, and very low overall survival. Dihydroartemisinin (DHA), an anti-malarial drug approved by the Food and Drug Administration (FDA), inhibited cell growth in HCC. The Warburg effect was one of the ten new hallmarks of cancer. Solute carrier family 2 member 1 (SLC2A1) was a crucial carrier for glucose to enter target cells in the Warburg effect. Yes-associated transcriptional regulator 1 (YAP1), an effector molecule of the hippo pathway, played a crucial role in promoting the development of HCC. This study sought to determine the role of DHA in the SLC2A1 mediated Warburg effect in HCC. In this study, DHA inhibited the Warburg effect and SLC2A1 in HepG2215 cells and mice with liver tumors in situ. Meanwhile, DHA inhibited YAP1 expression by inhibiting YAP1 promoter binding protein GA binding protein transcription factor subunit beta 1 (GABPB1) and cAMP responsive element binding protein 1 (CREB1). Further, YAP1 knockdown/knockout reduced the Warburg effect and SLC2A1 expression by shYAP1-HepG2215 cells and Yap1^LKO mice with liver tumors. Taken together, our data indicated that YAP1 knockdown/knockout reduced the SLC2A1 mediated Warburg effect by shYAP1-HepG2215 cells and Yap1^LKO mice with liver tumors induced by DEN/TCPOBOP. DHA, as a potential YAP1 inhibitor, suppressed the SLC2A1 mediated Warburg effect in HCC.

Case report: A case of Culler-Jones syndrome caused by a novel mutation of GLI2 gene and literature review

Culler-Jones syndrome is a rare clinical phenomenon with diverse manifestations and is prone to misdiagnosis. We report one patient who presented with a 10-year history of anosmia and a 1-year history of epididymal pain. Kallmann syndrome was suspected initially. The results of his laboratory tests, imaging, and genetic testing, however, combined to provide a conclusive diagnosis of Culler-Jones syndrome. With the aid of high-throughput sequencing technology, the GLI2 gene c.527A>G (p.Tyr176Cys) heterozygous mutation in the child was identified. No published works have yet described this mutation site. We described Culler-Jones syndrome in a child at length. We recommend that Culler-Jones syndrome be taken into account when considering the spectrum of disorders associated with abnormal growth and development in children. Once diagnosed, individualized hormone replacement treatment is required for each patient.

Engineering Electrodes with Robust Conducting Hydrogel Coating for Neural Recording and Modulation

Coating conventional metallic electrodes with conducting polymers has enabled the essential characteristics required for bioelectronics, such as biocompatibility, electrical conductivity, mechanical compliance, and the capacity for structural and chemical functionalization of the bioelectrodes. However, the fragile interface between the conducting polymer and the electrode in wet physiological environment greatly limits their utility and reliability. Here, a general yet reliable strategy to seamlessly interface conventional electrodes with conducting hydrogel coatings is established, featuring tissue-like modulus, highly-desirable electrochemical properties, robust interface, and long-term reliability. Numerical modeling reveals the role of toughening mechanism, synergy of covalent anchorage of long-chain polymers, and chemical cross-linking, in improving the long-term robustness of the interface. Through in vivo implantation in freely-moving mouse models, it is shown that stable electrophysiological recording can be achieved, while the conducting hydrogel-electrode interface remains robust during the long-term low-voltage electrical stimulation. This simple yet versatile design strategy addresses the long-standing technical challenges in functional bioelectrode engineering, and opens up new avenues for the next-generation diagnostic brain-machine interfaces.

Integrated analysis of transcriptomics and metabolomics in human hepatocellular carcinoma HepG2215 cells after YAP1 knockdown

Yes-associated protein 1 (YAP1) plays a critical role in hepatocellular carcinoma (HCC). Inhibition of YAP1 expression suppresses HCC progression, but the underlying mechanism is still unclear. In this study, we studied the effects and molecular mechanisms of YAP1 knockdown on the growth and metabolism in human HCC HepG2215 cells. Inhibition of YAP1 expression inhibits the proliferation and metastasis in HepG2215 cells, and differentially expressed genes (DEGs) and metabolites were identified in shYAP1-HepG2215 cells. Further, 805 DEGs, mainly associated with metabolism and particularly lipid metabolism, were identified by transcriptome sequencing analyses in shYAP1-HepG2215 cells. YAP1 knockdown increased albumin (ALB) levels by Protein-protein interaction (PPI) network analyses in HepG2215 cells. Metabolomic profiling identified 37 metabolites with significant differences in the shYAP1 group, and amino acid metabolism generally decreased in the shYAP1 group. Comprehensive analysis of transcriptomics and metabolomics revealed that the ATP-binding cassette (ABC) transporters play a central role after YAP1 knockdown in HepG2215 cells. Therefore, YAP1 knockdown inhibited HCC growth, which affected the metabolism of lipids and amino acids by regulating the expression of ALB and ABC transporters in HepG2215 cells.

Reuse of steel slag as a photocatalyst for tetracycline degradation: mechanism of oxygen vacancies

High value-added utilization of solid waste steel slag for the photocatalytic degradation of tetracycline is realized by alkali activation.

Preparation of Salt-Induced Ultra-Stretchable Nanocellulose Composite Hydrogel for Self-Powered Sensors

Hydrogels have attracted much attraction for promising flexible electronics due to the versatile tunability of the properties. However, there is still a big obstacle to balance between the multi-properties and performance of wearable electronics. Herein, we propose a salt-percolated nanocellulose composite hydrogel which was fabricated via radical polymerization with acrylic acid as polymer networks (NaCl-CNCs-PAA). CNCs were utilized as a reinforcing agent to enhance the mechanical properties of the hydrogel. Moreover, the abundant hydroxyl groups endow the hydrogel with noncovalent interactions, such as hydrogen bonding, and the robustness of the hydrogel was thus improved. NaCl incorporation induced the electrostatic interaction between CNCs and PAA polymer blocks, thus facilitating the improvement of the stretchability of the hydrogel. The as-obtained hydrogel exhibited excellent stretchability, ionic conductivity, mechanical robustness and anti-freezing properties, making it suitable for self-powered sensing applications. A single-mode triboelectric nanogenerator (C-TENG) was fabricated by utilizing the composite hydrogel as electrodes. This C-TENG could effectively convert biomechanical energy to electricity (89.2 V, 1.8 µA, 32.1 nC, and the max power density of 60.8 mW m^-2 at 1.5 Hz.) Moreover, the composite hydrogel was applied for strain sensing to detect human motions. The nanocellulose composite hydrogel can achieve the application as a power supply in integrated sensing systems and as a strain sensor for human motion detection.

NET-borne elastase prevents inflammatory relapse in intercritical gout

OBJECTIVES

Gout flares accompanied by urate lowering therapy (ULT) are prone to be related to the shrinkage of tophi from aggregated neutrophil extracellular traps (NETs) that had captured monosodium urate crystals in the tissues. In this study, we analysed the blocking effect of α1-antitrypsin on neutrophil elastase, which induced rapid inflammation in the presence of instable tophi.

METHODS

Serum cell-free DNA levels were compared between patients with various numbers of gout flares. We investigated whether serum cell-free DNA and α1-antitrypsin could be altered after ULT. A mimic of tophi formed in the murine peritoneal cavity by injection of MSU crystals was tested by immuno-fluorescence. Finally, we investigated the relapse of inflammation by α1-antitrypsin in two kinds of artificial tophi and in tophus-bearing mice.

RESULTS

Serum cell-free DNA correlated to the numbers of flares in patients with tophaceous gout. ULT induced serum cell-free DNA increase in patients with tophi. An increase of α1-antitrypsin was seen in patients with tophi who received ULT. Chalk-like tophi from the peritoneal cavity of mice after MSU crystals induced inflammation showed abundant co-expression of IL-1β and IL-6 associated NETs. α1-antitrypsin induced the relapse of inflammation during the spontaneous resolution of MSU crystal-induced peritonitis. We observed that α1-antitrypsin blocks the cytokine degradation by neutrophil elastase during the resolution phase of tophi. This article is protected by copyright. All rights reserved.

CONCLUSION

ULT causes shrinkage of the tophi reflected by an increase of the level of serum cell-free DNA. In the resolution phase of murine tophi, the NET-associated neutrophil elastase degrades proinflammatory cytokines and, thus, ameliorates inflammation.

Aryl hydrocarbon receptor activation drives polymorphonuclear myeloid-derived suppressor cell response and efficiently attenuates experimental Sjögren's syndrome

Myeloid-derived suppressor cells (MDSCs) comprise heterogeneous myeloid cell populations with immunosuppressive capacity that contribute to immune regulation and tolerance induction. We previously reported impaired MDSC function in patients with primary Sjögren's syndrome (pSS) and mice with experimental SS (ESS). However, the molecular mechanisms underlying MDSC dysfunction remain largely unclear. In this study, we first found that aryl hydrocarbon receptor (AhR) was highly expressed by human and murine polymorphonuclear MDSCs (PMN-MDSCs). Indole-3-propionic acid (IPA), a natural AhR ligand produced from dietary tryptophan, significantly promoted PMN-MDSC differentiation and suppressive function on CD4+ T cells. In contrast, feeding a tryptophan-free diet resulted in a decreased PMN-MDSC response, a phenotype that could be reversed by IPA supplementation. The functional importance of PMN-MDSCs was demonstrated in ESS mice by using a cell-depletion approach. Notably, AhR expression was reduced in PMN-MDSCs during ESS development, while AhR antagonism resulted in exacerbated ESS pathology and dysregulated T effector cells, which could be phenocopied by a tryptophan-free diet. Interferon regulatory factor 4 (IRF4), a repressive transcription factor, was upregulated in PMN-MDSCs during ESS progression. Chromatin immunoprecipitation analysis revealed that IRF4 could bind to the promoter region of AhR, while IRF4 deficiency markedly enhanced AhR-mediated PMN-MDSC responses. Furthermore, dietary supplementation with IPA markedly ameliorated salivary glandular pathology in ESS mice with restored MDSC immunosuppressive function. Together, our results identify a novel function of AhR in modulating the PMN-MDSC response and demonstrate the therapeutic potential of targeting AhR for the treatment of pSS.

Cutting-Edge Methods for Better Understanding Cells

Cells are microscopic yet fundamental elements of life [...].

[Long-term efficacy of low-dose rituximab treatment in patients with primary membranous nephropathy]

Objective: To explore the long-term efficacy of low-dose rituximab (RTX) treatment in patients with primary membranous nephropathy (PMN). Methods: Patients with biopsy-proven PMN who received low-dose RTX as initial or second-line regimen from August 2018 to May 2020 in the Department of Nephrology, Tianjin Medical University General Hospital were respectively enrolled. The clinical parameters of patients were urinary protein>3.5 g/24 h, serum albumin<30 g/L and estimated glomerular filtration rate (eGFR)>20 ml·min^-1·(1.73 m²)^-1. The treatment response of patients with PMN was observed during follow-up, and the remission rate of patients with urinary protein<8 g/24 h or ≥8 g/24 h, anti-PLA2R antibody<150 RU/ml or ≥150 RU/ml, eGFR≥ 60 ml·min^-1·(1.73 m²)^-1 or<60 ml·min^-1·(1.73 m²)^-1 were analyzed, respectively. Results: A total of 40 patients were enrolled, including 26 males and 14 females, aged (53±15) years. There were 14 patients received RTX as initial treatment and 26 patients as second-line therapy. The total median dose of RTX in the first course was 800 (425, 1 075) mg. The overall remission rate at the 1st, 3rd, 6th, 12th and 24th months were 12.5% (5/40), 17.5% (7/40), 47.5% (19/40), 57.5% (23/40), 60% (24/40), respectively. The median overall response time was 6.0 (3.0, 7.5) months. Two cases relapsed. Patients with remission (n=24) had a higher level of baseline eGFR [(93.9±28.0) vs (62.4±28.1) ml·min^-1·(1.73 m²)^-1, P=0.001), and a lower level of both urinary protein [5.9 (5.0, 6.5) vs 11.7 (8.6, 15.5) g/24 h, P<0.001] and anti-PLA2R antibody level [73 (29, 132) vs 453 (182, 950) RU/ml, P=0.004] than those without remission (n=16) 24 month after treatment. There was no statistically significant difference in the remission rate between initial and second-line treatment (P=0.101). Moreover, patients had a higher remission rate in urinary protein<8 g/24 h group (21/26 vs 3/14, P<0.001), anti-PLA2R antibody<150 RU/ml group (16/19 vs 5/16, P=0.002) and eGFR ≥ 60 ml·min^-1·(1.73 m²)^-1 group (22/29 vs 2/11, P=0.003). Conclusions: Low-dose RTX treatment in PMN is effective during long-term follow-up, and has a lower recurrence rate. The results also suggest that it is more suitable for patients with baseline urinary protein<8 g/24 h, anti-PLA2R antibody<150 RU/ml and eGFR≥ 60 ml·min^-1·(1.73 m²)^-1.

Multi-omics characterization of autophagy-related molecular features for therapeutic targeting of autophagy

Autophagy is a major contributor to anti-cancer therapy resistance. Many efforts have been made to understand and overcome autophagy-mediated therapy resistance, but these efforts have been unsuccessful in clinical applications. In this study, we establish an autophagy signature to estimate tumor autophagy status. We then classify approximately 10,000 tumor samples across 33 cancer types from The Cancer Genome Atlas into autophagy score-high and autophagy score-low groups. We characterize the associations between multi-dimensional molecular features and tumor autophagy, and further analyse the effects of autophagy status on drug response. In contrast to the conventional view that the induction of autophagy serves as a key resistance mechanism during cancer therapy, our analysis reveals that autophagy induction may also sensitize cancer cells to anti-cancer drugs. We further experimentally validate this phenomenon for several anti-cancer drugs in vitro and in vivo, and reveal that autophagy inducers potentially sensitizes tumor cells to etoposide through downregulating the expression level of DDIT4. Our study provides a comprehensive landscape of molecular alterations associated with tumor autophagy and highlights an opportunity to leverage multi-omics analysis to utilize multiple drug sensitivity induced by autophagy.

AnimalTFDB 4.0: a comprehensive animal transcription factor database updated with variation and expression annotations

Transcription factors (TFs) are proteins that interact with specific DNA sequences to regulate gene expression and play crucial roles in all kinds of biological processes. To keep up with new data and provide a more comprehensive resource for TF research, we updated the Animal Transcription Factor Database (AnimalTFDB) to version 4.0 (http://bioinfo.life.hust.edu.cn/AnimalTFDB4/) with up-to-date data and functions. We refined the TF family rules and prediction pipeline to predict TFs in genome-wide protein sequences from Ensembl. As a result, we predicted 274 633 TF genes and 150 726 transcription cofactor genes in AnimalTFDB 4.0 in 183 animal genomes, which are 86 more species than AnimalTFDB 3.0. Besides double data volume, we also added the following new annotations and functions to the database: (i) variations (including mutations) on TF genes in various human cancers and other diseases; (ii) predicted post-translational modification sites (including phosphorylation, acetylation, methylation and ubiquitination sites) on TFs in 8 species; (iii) TF regulation in autophagy; (iv) comprehensive TF expression annotation for 38 species; (v) exact and batch search functions allow users to search AnimalTFDB flexibly. AnimalTFDB 4.0 is a useful resource for studying TF and transcription regulation, which contains comprehensive annotation and classification of TFs and transcription cofactors.

[Transcriptomic analysis of tuberculosis peptide-based vaccine MP3RT in humanized mice]

Objective: To identify the differentially expressed genes (DEGs) induced by tuberculosis peptide-based vaccine MP3RT in a humanized mouse model using transcriptomics technology. Methods: This study was conducted from August 2019 to February 2022. We used edgeR software to screen DEGs with a fold change greater than or equal to 1.5 and a P value less than 0.05 as screening conditions. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and protein interaction network analyses were performed on the screened DEGs. Then, these DEGs were verified by RT-qPCR and statistically analyzed by GraphPad Prism 8 software. Results: A total of 367 DEGs (214 up-regulated and 153 down-regulated) were identified by transcriptomics. Bioinformatics analysis showed that the GO enrichment of the DEGs mentioned above significantly focused on cell metabolism, growth, apoptosis, inflammation, and other terms. In contrast, the KEGG enrichment significantly focused on inflammatory pathways such as the MAPK signaling pathway. Protein interaction network analysis showed that protein Abl1 had the highest aggregation, the highest aggregation coefficient, and the best connectivity. RT-qPCR results showed that gene expressions of cpne4 (t=2.48, P=0.048 0), h2-q10 (t=2.95, P=0.025 6), mef2c (t=2.87, P=0.028 4), cr2 (t=3.23, P=0.178), ablim1 (t=2.91, P=0.033 5), dll1 (t=2.70, P=0.027 3) and ms4a2 (t=3.03, P=0.019 2) genes in the MP3RT group were significantly up-regulated than those in the PBS group, while gene expressions of cd163l1 (t=2.56, P=0.043 0), il1r1 (t=2.91, P=0.022 7) and cd34 (t=2.42, P=0.046 2) genes in the MP3RT group were significantly down-regulated than those in the PBS group. Conclusions: The MP3RT vaccine induced 367 DEGs in humanized mice, which were associated with metabolic and immune responses. Furthermore, we found that p38 MAPK and JNK/MAPK signaling pathways played an important role in the molecular mechanism of the MP3RT vaccine.

Particulate matter exposure at urban traffic intersection during haze episodes: A case study in Changsha

Urban intersection has been identified as a major contributor to the total personal exposure and short-term high exposure of particulate matter (PM) in modern cities. The main aim of this study was to get a better understanding of the determinants of traffic-related PM temporal variations and personal exposure to PMs at a viaduct-covered intersection controlled by traffic signals during the winter haze episodes. A two-day field sampling campaign was conducted with a portable device during evening rush hour and measured the PMs in the 0.3-10 μm size range both on the surface crosswalk and underground passage. PM variations and related cumulative respiratory deposition dose (RDD) along two routes with six road crossing scenarios were estimated on a severe pollution day and a typical day for both adults and children, respectively. The PM concentration on the severe pollution day ranged 59.2-67.9 μg/m³ for PM₁, 163.8-257.0 μg/m³ for PM₂, and 258.2-469.1 μg/m³ for PM₁₀, respectively, as compared to 47.9-57.9 μg/m³for PM₁, 112.7-199.8 μg/m³ for PM₂, and 151.0-301.0 μg/m³ for PM₁₀ on the typical day, respectively. The variability could be explained largely by the built-up environment, traffic component, signal setting, and ventilation condition. Our data suggest that an appropriate setting of the traffic signal would help reduce the personal exposure dose on the surface crosswalk at urban intersections and the ventilation condition had a significant influence on local PM distributions inside the underground passage. Results here provide possible suggestions for the future design of a walkable city.

S6K1 amplification confers innate resistance to CDK4/6 inhibitors through activating c-Myc pathway in patients with estrogen receptor-positive breast cancer

Background

CDK4/6 inhibitors combined with endocrine therapy has become the preferred treatment approach for patients with estrogen receptor-positive metastatic breast cancer. However, the predictive biomarkers and mechanisms of innate resistance to CDK4/6 inhibitors remain largely unknown. We sought to elucidate the molecular hallmarks and therapeutically actionable features of patients with resistance to CDK4/6 inhibitors.

Methods

A total of 36 patients received palbociclib and endocrine therapy were included in this study as the discovery cohort. Next-generation sequencing of circulating tumour DNA in these patients was performed to evaluate somatic alterations associated with innate resistance to palbociclib. Then the candidate biomarker was validated in another independent cohort of 104 patients and publicly available datasets. The resistance was verified in parental MCF-7 and T47D cells, as well as their derivatives with small interfering RNA transfection and lentivirus infection. The relevant mechanism was examined by RNA sequencing, chromatin immunoprecipitation and luciferase assay. Patient-derived organoid and patient-derived xenografts studies were utilized to evaluated the antitumor activity of rational combinations.

Results

In the discovery cohort, S6K1 amplification (3/35, 9%) was identified as an important reason for innate resistance to CDK4/6 inhibitors. In the independent cohort, S6K1 was overexpressed in 15/104 (14%) patients. In those who had received palbociclib treatment, patients with high-expressed S6K1 had significantly worse progression free survival than those with low S6K1 expression (hazard ratio = 3.0, P = 0.0072). Meta-analysis of public data revealed that patients with S6K1 amplification accounted for 12% of breast cancers. Breast cancer patients with high S6K1 expression had significantly worse relapse-free survival (hazard ratio = 1.31, P < 0.0001). In breast cancer cells, S6K1 overexpression, caused by gene amplification, was sufficient to promote resistance to palbociclib. Mechanistically, S6K1 overexpression increased the expression levels of G1/S transition-related proteins and the phosphorylation of Rb, mainly through the activation of c-Myc pathway. Notably, this resistance could be abrogated by the addition of mTOR inhibitor, which blocked the upstream of S6K1, in vitro and in vivo.

Conclusions

S6K1 amplification is an important mechanism of innate resistance to palbociclib in breast cancers. Breast cancers with S6K1 amplification could be considered for combinations of CDK4/6 and S6K1 antagonists.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01642-5.