Short-distance vesicle transport via phase separation.

In addition to long-distance molecular motor-mediated transport, cellular vesicles also need to be moved at short distances with defined directions to meet functional needs in subcellular compartments but with unknown mechanisms. Such short-distance vesicle transport does not involve molecular motors. Here, we demonstrate, using synaptic vesicle (SV) transport as a paradigm, that phase separation of synaptic proteins with vesicles can facilitate regulated, directional vesicle transport between different presynaptic bouton sub-compartments. Specifically, a large coiled-coil scaffold protein Piccolo, in response to Ca2+ and via its C2A domain-mediated Ca2+ sensing, can extract SVs from the synapsin-clustered reserve pool condensate and deposit the extracted SVs onto the surface of the active zone protein condensate. We further show that the Trk-fused gene, TFG, also participates in COPII vesicle trafficking from ER to the ER-Golgi intermediate compartment via phase separation. Thus, phase separation may play a general role in short-distance, directional vesicle transport in cells.

The HEAT repeat protein HPO-27 is a lysosome fission factor.

Lysosomes are degradation and signalling centres crucial for homeostasis, development and ageing1. To meet diverse cellular demands, lysosomes remodel their morphology and function through constant fusion and fission2,3. Little is known about the molecular basis of fission. Here we identify HPO-27, a conserved HEAT repeat protein, as a lysosome scission factor in Caenorhabditis elegans. Loss of HPO-27 impairs lysosome fission and leads to an excessive tubular network that ultimately collapses. HPO-27 and its human homologue MROH1 are recruited to lysosomes by RAB-7 and enriched at scission sites. Super-resolution imaging, negative-staining electron microscopy and in vitro reconstitution assays reveal that HPO-27 and MROH1 self-assemble to mediate the constriction and scission of lysosomal tubules in worms and mammalian cells, respectively, and assemble to sever supported membrane tubes in vitro. Loss of HPO-27 affects lysosomal morphology, integrity and degradation activity, which impairs animal development and longevity. Thus, HPO-27 and MROH1 act as self-assembling scission factors to maintain lysosomal homeostasis and function.

Observation of Emergent Superconductivity in the Topological Insulator Ta2Pd3Te5 via Pressure Manipulation.

Topological insulators offer significant potential to revolutionize diverse fields driven by nontrivial manifestations of their topological electronic band structures. However, the realization of superior integration between exotic topological states and superconductivity for practical applications remains a challenge, necessitating a profound understanding of intricate mechanisms. Here, we report experimental observations for a novel superconducting phase in the pressurized second-order topological insulator candidate Ta2Pd3Te5, and the high-pressure phase maintains its original ambient pressure lattice symmetry up to 45 GPa. Our in situ high-pressure synchrotron X-ray diffraction, electrical transport, infrared reflectance, and Raman spectroscopy measurements, in combination with rigorous theoretical calculations, provide compelling evidence for the association between the superconducting behavior and the densified phase. The electronic state change around 20 GPa was found to modify the topology of the Fermi surface directly, which synergistically fosters the emergence of robust superconductivity. In-depth comprehension of the fascinating properties exhibited by the compressed Ta2Pd3Te5 phase is achieved, highlighting the extraordinary potential of topological insulators for exploring and investigating high-performance electronic advanced devices under extreme conditions.

Positive GLI1/INHBA feedback loop drives tumor progression in gastric cancer.

GLI1, a key transcription factor of the Hedgehog (Hh) signaling pathway, plays an important role in the development of cancer. However, the function and mechanisms by which GLI1 regulates gene transcription are not fully understood in gastric cancer (GC). Here, we found that GLI1 induced the proliferation and metastasis of GC cells, accompanied by transcriptional upregulation of INHBA. This increased INHBA expression exerted a promoting activity on Smads signaling and then transcriptionally activated GLI1 expression. Notably, our results demonstrate that disrupting the interaction between GLI1 and INHBA could inhibit GC tumorigenesis in vivo. More intriguingly, we confirmed the N6-methyladenosine (m6A) activation mechanism of the Helicobacter pylori/FTO/YTHDF2/GLI1 pathway in GC cells. In conclusion, our study confirmed that the GLI1/INHBA positive feedback loop influences GC progression and revealed the mechanism by which H. pylori upregulates GLI1 expression through m6A modification. This positive GLI1/INHBA feedback loop suggests a novel noncanonical mechanism of GLI1 activity in GC and provides potential therapeutic targets for GC treatment.

Genome-wide analysis of plant miRNA action clarifies levels of regulatory dynamics across developmental contexts.

Development of complex organisms requires the delicate and dynamic spatiotemporal regulation of gene expression. Central to this are microRNAs (miRNAs). These mobile small RNAs offer specificity in conveying positional information and versatility in patterning the outcomes of gene expression. However, the parameters that shape miRNA output during development are still to be clarified. Here, we address this question on a genome-wide scale, using the maize shoot apex as a model. We show that patterns and levels of miRNA accumulation are largely determined at the transcriptional level, but are finessed post-transcriptionally in a tissue-dependent manner. The stem cell environments of the shoot apical meristem and vasculature appear particularly liable to this. Tissue-specific effects are also apparent at the level of target repression, with target cleavage products in the vasculature exceeding those of other tissues. Our results argue against a clearance mode of regulation purely at the level of transcript cleavage, leading us to propose that transcript cleavage provides a baseline level of target repression, onto which miRNA-driven translational repression can act to toggle the mode of target regulation between clearance and rheostat. Our data show how the inherent complexities of miRNA pathways allow the accumulation and activity of these small RNAs to be tailored in space and time to bring about the gene expression versatility needed during development.

PLEK2 mediates metastasis and invasion via α5-nAChR activation in nicotine-induced lung adenocarcinoma.

Evidence has shown a strong relationship between smoking and epithelial mesenchymal transition (EMT). α5-nicotinic acetylcholine receptor (α5-nAChR) contributes to nicotine-induced lung cancer cell EMT. The cytoskeleton-associated protein PLEK2 is mainly involved in cytoskeletal protein recombination and cell stretch migration regulation, which is closely related to EMT. However, little is known about the link between nicotine/α5-nAChR and PLEK2 in lung adenocarcinoma (LUAD). Here, we identified a link between α5-nAChR and PLEK2 in LUAD. α5-nAChR expression was correlated with PLEK2 expression, smoking status and lower survival in vivo. α5-nAChR mediated nicotine-induced PLEK2 expression via STAT3. α5-nAChR/PLEK2 signaling is involved in LUAD cell migration, invasion and stemness. Moreover, PLEK2 was found to interact with CFL1 in nicotine-induced EMT in LUAD cells. Furthermore, the functional link among α5-nAChR, PLEK2 and CFL1 was confirmed in mouse xenograft tissues and human LUAD tissues. These findings reveal a novel α5-nAChR/PLEK2/CFL1 pathway involved in nicotine-induced LUAD progression.

PKP2 induced by YAP/TEAD4 promotes malignant progression of gastric cancer.

Gastric cancer (GC) exhibits significant heterogeneity and its prognosis remains dismal. Therefore, it is essential to investigate new approaches for diagnosing and treating GC. Desmosome proteins are crucial for the advancement and growth of cancer. Plakophilin-2 (PKP2), a member of the desmosome protein family, frequently exhibits aberrant expression and is strongly associated with many tumor types' progression. In this study, we found upregulation of PKP2 in GC. Further correlation analysis showed a notable association between increased PKP2 expression and both tumor stage and poor prognosis in individuals diagnosed with gastric adenocarcinoma. In addition, our research revealed that the Yes-associated protein1 (YAP1)/TEAD4 complex could stimulate the transcriptional expression of PKP2 in GC. Elevated PKP2 levels facilitate activation of the AKT/mammalian target of rapamycin signaling pathway, thereby promoting the malignant progression of GC. By constructing a mouse model, we ultimately validated the molecular mechanism and function of PKP2 in GC. Taken together, these discoveries suggest that PKP2, as a direct gene target of YAP/TEAD4 regulation, has the potential to be used as an indication of GC progression and prognosis. PKP2 is expected to be a promising therapeutic target for GC.

Record-High T_{c} and Dome-Shaped Superconductivity in a Medium-Entropy Alloy TaNbHfZr under Pressure up to 160 GPa.

Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the discovery of the body-centered cubic (bcc) HEA superconductor in 2014. Until now, the superconducting transition temperature (T_{c}) of most MEA and HEA superconductors has not exceeded 10 K. Here, we report a TaNbHfZr bulk MEA superconductor crystallized in the BCC structure with a T_{c} of 15.3 K which set a new record. During compression, T_{c} follows a dome-shaped curve. It reaches a broad maximum of roughly 15 K at around 70 GPa before decreasing to 9.3 K at 157.2 GPa. First-principles calculations attribute the dome-shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency ω_{log} and the simultaneous suppression of the electron-phonon coupling constant λ. Thus, TaNbHfZr MEA may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions.

Advances towards genome-based acute myeloid leukemia classification: A comparative analysis of WHO-HAEM4R, WHO-HAEM5, and International Consensus Classification.

Two recent guidelines, the 5th edition of the World Health Organization Classification of Haematolymphoid Tumours (WHO-HAEM5) and the International Consensus Classification (ICC), were published to refine the diagnostic criteria of acute myeloid leukemia (AML). They both consider genomic features more extensively and expand molecularly defined AML subtypes. In this study, we compared the classifications of 1135 AML cases under both criteria. According to WHO-HAEM5 and ICC, the integration of whole transcriptome sequencing, targeted gene mutation screening, and conventional cytogenetic analysis identified defining genetic abnormalities in 89% and 90% of AML patients, respectively. The classifications displayed discrepancies in 16% of AML cases after being classified using the two guidelines, respectively. Both new criteria significantly reduce the number of cases defined by morphology and differentiation. However, their clinical implementation heavily relies on comprehensive and sophisticated genomic analysis, including genome and transcriptome levels, alongside the assessment of pathogenetic somatic and germline variations. Discrepancies between WHO-HAEM5 and ICC, such as the assignment of RUNX1 mutations, the rationality of designating AML with mutated TP53 as a unique entity, and the scope of rare genetic fusions, along with the priority of concurrent AML-defining genetic abnormalities, are still pending questions requiring further research for more elucidated insights.

NiRu-Mo2Ti2C3O2 as an efficient catalyst for alkaline hydrogen evolution reactions: the role of bimetallic site interactions in promoting Volmer-step kinetics.

The Volmer step in alkaline hydrogen evolution reactions (HERs), which supplies H* to the following steps by cleaving H-O-H bonds, is considered the rate-determining step of the overall reaction. The Volmer step involves water dissociation and adsorbed hydroxyl (*OH) desorption; Ru-based catalysts display a compelling water dissociation process in an alkaline HER. Unfortunately, the strong affinity of Ru for *OH blocks the active sites, resulting in unsatisfactory performance during HER processes. Hence, this study investigates a series of key descriptors (ΔG*H2O, ΔG*H-OH, ΔG*H, and ΔG*OH) of TM (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, or Pt)-Ru/Mo2Ti2C3O2 to systematically explore the effects of bimetallic site interactions on the kinetics of the Volmer step. The results indicate that bimetallic catalysts effectively reduced the strong adsorption of *OH on Ru sites; especially, the NiRu diatomic state shows the highest electron-donating ability, which promoted the smooth migration of *OH from Ru sites to Ni sites. Therefore, Ru, Ni and MXenes are suitable to serve as water adsorption and dissociation sites, *OH desorption sites, and H2 release sites, respectively. Ultimately, NiRu/Mo2Ti2C3O2 promotes Volmer kinetics and has the potential to improve alkaline HERs. This work provides theoretical support for the construction of synergistic MXene-based diatomic catalysts and their wide application in the field of alkaline HERs.

Plasma Steroid Profiling Combined With Machine Learning for the Differential Diagnosis in Mild Autonomous Cortisol Secretion From Nonfunctioning Adenoma in Patients With Adrenal Incidentalomas.

OBJECTIVE: To assess the diagnostic value of combining plasma steroid profiling with machine learning (ML) in differentiating between mild autonomous cortisol secretion (MACS) and nonfunctioning adenoma (NFA) in patients with adrenal incidentalomas. METHODS: The plasma steroid profiles data in the laboratory information system were screened from January 2021 to December 2023. EXtreme Gradient Boosting was applied to establish diagnostic models using plasma 24-steroid panels and/or clinical characteristics of the subjects. The SHapley Additive exPlanation (SHAP) method was used for explaining the model. RESULTS: Seventy-six patients with MACS and 86 patients with NFA were included in the development and internal validation cohort while the external validation cohort consisted of 27 MACS and 21 NFA cases. Among 5 ML models evaluated, eXtreme Gradient Boosting demonstrated superior performance with an area under the curve of 0.77 using 24 steroid hormones. The SHAP method identified 5 steroids that exhibited optimal performance in distinguishing MACS from NFA, namely dehydroepiandrosterone, 11-deoxycortisol, 11ß-hydroxytestosterone, testosterone, and dehydroepiandrosteronesulfate. Upon incorporating clinical features into the model, the area under the curve increased to 0.88, with a sensitivity of 0.77 and specificity of 0.82. Furthermore, the results obtained through SHAP revealed that lower levels of testosterone, dehydroepiandrosterone, low-density lipoprotein cholesterol, body mass index, and adrenocorticotropic hormone along with higher level of 11-deoxycortisol significantly contributed to the identification of MACS in the model. CONCLUSIONS: We have elucidated the utilization of ML-based steroid profiling to discriminate between MACS and NFA in patients with adrenal incidentalomas. This approach holds promise for distinguishing these 2 entities through a single blood collection.

Acetylcholine promotes chronic stress-induced lung adenocarcinoma progression via α5-nAChR/FHIT pathway.

Chronic stress significantly elevates the expression levels of various neurotransmitters in the tumour microenvironment, thereby promoting the cell growth and metastasis of lung adenocarcinoma (LUAD). However, the role of chronic stress in the progression of LUAD remains unclear. In this study, we found that chronic restraint stress increases the levels of the neurotransmitter acetylcholine (ACh), and the α5-nicotinic acetylcholine receptor (α5-nAChR) and decreased fragile histidine triad (FHIT) expression in vivo. Crucially, the increased ACh levels promoted LUAD cell migration and invasion via modulation of the α5-nAChR/DNA methyltransferase 1 (DNMT1)/FHIT axis. In a chronic unpredictable stress (CUMS) mouse model, chronic stress promotes tumour development, accompanied by changes in α5-nAChR, DNMT1, FHIT, and vimentin. Together, these findings reveal a novel chronic stress-mediated LUAD signalling pathway: chronic stress enforces lung adenocarcinoma cell invasion and migration via the ACh/α5-nAChR/FHIT axis, which could be a potential therapeutic target for chronic stress-related LUAD.

Targeted ferritinophagy in gastrointestinal cancer: from molecular mechanisms to implications.

Gastrointestinal cancer is a significant global health burden, necessitating the development of novel therapeutic strategies. Emerging evidence has highlighted the potential of targeting ferritinophagy as a promising approach for the treatment of gastrointestinal cancer. Ferritinophagy is a form of selective autophagy that is mediated by the nuclear receptor coactivator 4 (NCOA4). This process plays a crucial role in regulating cellular iron homeostasis and has been implicated in various pathological conditions, including cancer. This review discusses the molecular mechanisms underlying ferritinophagy and its relevance to gastrointestinal cancer. Furthermore, we highlight the potential therapeutic implications of targeting ferritinophagy in gastrointestinal cancer. Several approaches have been proposed to modulate ferritinophagy, including small molecule inhibitors and immunotherapeutic strategies. We discuss the advantages and challenges associated with these therapeutic interventions and provide insights into their potential clinical applications.

Effectiveness Differences of Ranibizumab and Aflibercept Action in the Treatment of Diabetic Retinopathy.

Objective: To compare the difference in the effectiveness of ranibizumab (LU) and aflibercept (AF) in the treatment of diabetic retinopathy (DR). Methods: Ninety-four patients with DR admitted to Sunshine Union Hospital from August 2020 to February 2022 were selected for the study and were divided into LU group (n = 47) and AF group (n = 47) according to the random number table method. Both groups underwent 25G vitrectomy in our hospital, with LU injected into the vitreous before surgery in the LU group and AF in the AF group. Vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in the pre-and post-injection atrial water were compared between the two groups, and the operative time, intraoperative bleeding, and the occurrence of medically induced fissures were recorded in both groups. In addition, the expression of best corrected visual acuity (BCVA), Central Macular Thickness (CMT), and inflammatory factors were compared before and after surgery. Finally, patients were counted for adverse reactions and prognosis of DR recurrence during treatment. Results: After injection, VEGF decreased and PEDF increased in both groups (P < .001). There were no differences in operative time (P = .604), intraoperative bleeding rate (P = .694), the incidence of medically induced fissure (P = .557), BCVA [P = .665 (T0), P > .999 (T1), P = .727 (T2)], and CMT [P = .688 (T0), P = .065 (T1), P = .148 (T2)] between the two groups, while IL-6, IL-8, and MMP-9 were lower in the AF group than in the LU group at 2 months after surgery (P < .001). Finally, there was no difference between both groups in terms of adverse effects and prognosis of DR recurrence rate (P = 1.000, .478). Conclusion: Both vitreous cavity injections of LU and AF can effectively reduce the expression of vascular-related factors in the atrial fluid of DR patients, but AF has a more significant inhibitory effect on the level of inflammatory factors in patients in the short term after treatment.

STAT5A modulates gastric cancer progression via upregulation of CD44.

OBJECTIVE: Signal transduction and transcriptional activator 5A (STAT5A), which has been reported to be frequently phosphorylated in tumors, plays pivotal roles in tumor progression. However, the role of STAT5A in gastric cancer (GC) progression and the downstream targets of STAT5A remain largely unknown. METHODS: The expression of STAT5A and CD44 were assessed. GC cells were treated with altered STAT5A and CD44 to evaluate their biological functions. Nude mice were given injections of genetically manipulated GC cells and growth of xenograft tumors and metastases was measured. RESULTS: The increased level of p-STAT5A is associated with tumor invasion and poor prognosis in GC. STAT5A promoted GC cell proliferation by upregulating CD44 expression. STAT5A directly binds to the CD44 promoter and promotes its transcription. CONCLUSIONS: The STAT5A/CD44 pathway plays a critical role in GC progression, promising potential clinical applications for improving treatment of GC.

Volumetric B-mode ultrasound and Doppler Imaging: Automatic Tracking With One Single Camera.

Vascular diseases may occur in the upper extremities, and the lesions can span the entire length of the blood vessel. One of the most popular methods to identify vascular disorders is ultrasound Doppler imaging. However, traditional two-dimensional (2D) ultrasound Doppler imaging cannot capture the entire length of a long vessel in one image. Medical professionals often have to painstakingly reconstruct three-dimensional (3D) data using 2D ultrasound images to locate the lesions, especially for large blood vessels. 3D ultrasound Doppler imaging can display the morphological structure of blood vessels and the distribution of lesions more directly, providing a more comprehensive view compared to 2D imaging. In this work, we propose a wide-range 3D volumetric ultrasound Doppler imaging system with dual modality, in which a high-definition camera is adopted to automatically track the movement of the ultrasound transducer, simultaneously capturing a corresponding sequence of 2D ultrasound Doppler images. We conducted experiments on human arms using our proposed system and separately with X-ray computerized tomography (X-CT). The comparison results prove the potential value of our proposed system in the diagnosis of arm vascular diseases.

The dynamic features and microbial mechanism of nitrogen transformation for hydrothermal aqueous phase as fertilizer in dryland soil.

Hydrothermal aqueous phase (HAP) contains abundant organics and nutrients, which have potential to partially replace chemical fertilizers for enhancing plant growth and soil quality. However, the underlying reasons for low available nitrogen (N) and high N loss in dryland soil remain unclear. A cultivation experiment was conducted using HAP or urea to supply 160 mg N kg-1 in dryland soil. The dynamic changes of soil organic matters (SOMs), pH, N forms, and N cycling genes were investigated. Results showed that SOMs from HAP stimulated urease activity and ureC, which enhanced ammonification in turn. The high-molecular-weight SOMs relatively increased during 5-30 d and then biodegraded during 30-90 d, which SUV254 changed from 0.51 to 1.47 to 0.29 L-1 m-1. This affected ureC that changed from 5.58 to 5.34 to 5.75 lg copies g-1. Relative to urea, addition HAP enhanced ON mineralization by 8.40 times during 30-90 d due to higher ureC. It decreased NO3-N by 65.35%-77.32% but increased AOB and AOA by 0.25 and 0.90 lg copies g-1 at 5 d and 90 d, respectively. It little affected nirK and increased nosZ by 0.41 lg copies g-1 at 90 d. It increased N loss by 4.59 times. The soil pH for HAP was higher than that for urea after 11 d. The comprehensive effects of high SOMs and pH, including ammonification enhancement and nitrification activity inhibition, were the primary causes of high N loss. The core idea for developing high-efficiency HAP fertilizer is to moderately inhibit ammonification and promote nitrification.

Purification and Biochemical Characterization of Polyphenol Oxidase Extracted from Wheat Bran (Wan grano).

Currently, little is known about the characteristics of polyphenol oxidase from wheat bran, which is closely linked to the browning of wheat product. The wheat PPO was purified by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange column, and Superdex G-75 chromatography column. Purified wheat PPO activity was 11.05-fold higher, its specific activity was 1365.12 U/mg, and its yield was 8.46%. SDS-PAGE showed that the molecular weight of wheat PPO was approximately 21 kDa. Its optimal pH and temperature were 6.5 and 35 °C for catechol as substrate, respectively. Twelve phenolic substrates from wheat and green tea were used for analyzing the substrate specificity. Wheat PPO showed the highest affinity to catechol due to its maximum Vmax (517.55 U·mL-1·min-1) and low Km (6.36 mM) values. Docking analysis revealed strong affinities between catechol, gallic acid, EGCG, and EC with binding energies of -5.28 kcal/mol, -4.65 kcal/mol, -4.21 kcal/mol, and -5.62 kcal/mol, respectively, for PPO. Sodium sulfite, ascorbic acid, and sodium bisulfite dramatically inhibited wheat PPO activity. Cu2+ and Ca2+ at 10 mM were considered potent activators and inhibitors for wheat PPO, respectively. This report provides a theoretical basis for controlling the enzymatic browning of wheat products fortified with green tea.

α5-nAChR/STAT3/CD47 axis contributed to nicotine-related lung adenocarcinoma progression and immune escape.

OBJECTIVES: The CHRNΑ5 gene, which encodes the α5-nicotinic acetylcholine receptor (α5-nAChR), is related to lung cancer and nicotine addiction. Smoking is closely related to the immunosuppressive effect of macrophages. CD47, a phagocytosis checkpoint in macrophages, is a therapeutic target in various cancer types. Nevertheless, the relationship between α5-nAChR and CD47 in lung cancer is still unclear. METHODS AND RESULTS: The present study showed that α5-nAChR-mediated CD47 expression via STAT3 signaling, consequently leading to tumor progression and immune suppression in lung adenocarcinoma (LUAD). α5-nAChR expression was correlated with STAT3 expression, CD47 expression, smoking status and poor prognosis of LUAD in vivo. In vitro, α5-nAChR expression mediated the phosphorylation of STAT3, and phosphorylated STAT3 bound to the CD47 promoter and mediated CD47 expression. Downregulation of α5-nAChR and/or CD47 significantly reduced cell proliferation, migration, invasion, stemness and IL-10 expression, but increased TNF-α expression and phagocytosis of macrophages in LUAD. Furthermore, α5-nAChR/CD47 signaling contributed to the growth of subcutaneous xenograft tumors and liver metastasis of tumors in mice. CONCLUSION: The α5-nAChR/STAT3/CD47 axis contributed to the progression and immune escape of lung cancer and may be a potential target for LUAD immunotherapy.

Socioeconomic inequalities in cancer incidence and access to health services among children and adolescents in China: a cross-sectional study.

BACKGROUND: Despite the substantial burden caused by childhood cancer globally, childhood cancer incidence obtained in a nationwide childhood cancer registry and the accessibility of relevant health services are still unknown in China. We comprehensively assessed the most up-to-date cancer incidence in Chinese children and adolescents, nationally, regionally, and in specific population subgroups, and also examined the association between cancer incidence and socioeconomic inequality in access to health services. METHODS: In this national cross-sectional study, we used data from the National Center for Pediatric Cancer Surveillance, the nationwide Hospital Quality Monitoring System, and public databases to cover 31 provinces, autonomous regions, and municipalities in mainland China. We estimated the incidence of cancer among children (aged 0-14 years) and adolescents (aged 15-19 years) in China through stratified proportional estimation. We classified regions by socioeconomic status using the human development index (HDI). Incidence rates of 12 main groups, 47 subgroups, and 81 subtypes of cancer were reported and compared by sex, age, and socioeconomic status, according to the third edition of the International Classification of Childhood Cancer. We also quantified the geographical and population density of paediatric oncologists, pathology workforce, diagnoses and treatment institutions of paediatric cancer, and paediatric beds. We used the Gini coefficient to assess equality in access to these four health service indicators. We also calculated the proportions of cross-regional patients among new cases in our surveillance system. FINDINGS: We estimated the incidence of cancer among children (aged 0-14 years) and adolescents (aged 15-19 years) in China from Jan 1, 2018, to Dec 31, 2020. An estimated 121 145 cancer cases were diagnosed among children and adolescents in China between 2018 and 2020, with world standard age-standardised incidence rates of 122·86 (95% CI 121·70-124·02) per million for children and 137·64 (136·08-139·20) per million for adolescents. Boys had a higher incidence rate of childhood cancer (133·18 for boys vs 111·21 for girls per million) but a lower incidence of adolescent cancer (133·92 for boys vs 141·79 for girls per million) than girls. Leukaemias (42·33 per million) were the most common cancer group in children, whereas malignant epithelial tumours and melanomas (30·39 per million) surpassed leukaemias (30·08 per million) in adolescents as the cancer with the highest incidence. The overall incidence rates ranged from 101·60 (100·67-102·51) per million in very low HDI regions to 138·21 (137·14-139·29) per million in high HDI regions, indicating a significant positive association between the incidence of childhood and adolescent cancer and regional socioeconomic status (p<0·0001). The incidence in girls showed larger variation (48·45% from the lowest to the highest) than boys (36·71% from lowest to highest) in different socioeconomic regions. The population and geographical densities of most health services also showed a significant positive correlation with HDI levels. In particular, the geographical density distribution (Gini coefficients of 0·32-0·47) had higher inequalities than population density distribution (Gini coefficients of 0·05-0·19). The overall proportion of cross-regional patients of childhood and adolescent cancer was 22·16%, and the highest proportion occurred in retinoblastoma (56·54%) and in low HDI regions (35·14%). INTERPRETATION: Our study showed that the burden of cancer in children and adolescents in China is much higher than previously nationally reported from 2000 to 2015. The distribution of the accessibility of health services, as a social determinant of health, might have a notable role in the socioeconomic inequalities in cancer incidence among Chinese children and adolescents. With regards to achieving the Sustainable Development Goals, policy approaches should prioritise increasing the accessibility of health services for early diagnosis to improve outcomes and subsequently reduce disease burdens, as well as narrowing the socioeconomic inequalities of childhood and adolescent cancer. FUNDING: National Major Science and Technology Projects of China, National Natural Science Foundation of China, Chinese Academy of Engineering Consulting Research Project, Wu Jieping Medical Foundation, Beijing Municipal Administration of Hospitals Incubating Program.