Association of CTACK, IL-2, and IL-13 with increased risk of lung cancer: A Mendelian randomization study.

BACKGROUND: In recent years, relevant studies have reported that inflammatory cytokines are related to the occurrence of cancer. However, the correlation with lung cancer is not clear. This study used the Mendelian random grouping method to investigate the correlation between inflammatory factors and lung cancer in different populations. METHODS: We obtained the single nucleotide polymorphisms (SNPs) of inflammatory cytokines through the open database and the SNPs of lung cancer (European and East Asian) through the IEU OpenGWAS project. Inverse variance-weighted (IVW) MR analyses were used to determine the causalities of exposures and outcomes. Supplementary analyses were also performed using weighted median and MR-Egger regressions. Afterward, sensitivity analyses were performed to test the robustness. Search the ChEMBL database for target drugs and indications for CTACK, IL-2, and IL-13. RESULTS: By IVW method, we found that CTACK, IL-2, and IL-13 were associated with an increased risk of lung cancer in the European population (CTACK, OR = 1.098, 95 % CI 1.001-1.204, P = 0.047; IL-2, OR = 1.112, 95 % CI 1.009-1.225, P = 0.032; IL-13, OR = 1.068, 95 % CI 1.007-1.132, P = 0.029), while only IL-13 was associated with an increased risk of lung cancer in the East Asian population (IL-13, OR = 1.110, 95 % CI 1.010-1.220, P = 0.030). The weighted median and MR-Egger regression methods were in the same direction as the IVW effect sizes. Furthermore, no evidence of multidirectionality was detected using the MR-Egger intercept as a sensitivity analysis. Currently, there are no approved or phase III studied indications for CTACK, IL-2, and IL-13 targets in lung cancer. CONCLUSION: The study outcomes supported that the inflammatory cytokines CTACK, IL-2, and IL-13 increase the risk of lung cancer. There is a lack of indications for drugs in these three targets. We explored the causal relationship between inflammatory cytokines and lung cancer, providing a basis for future cancer prediction models and targets for anti-tumor therapy.

Edaphic regulation of soil organic carbon fractions in the mattic layer across the Qinghai-Tibetan Plateau.

The mattic layer is a main ecological function bearer of alpine meadow soils in the Qinghai-Tibet Plateau. It has high soil organic carbon (SOC) content with a variety of SOC fractions, which are thought to have different sensitivities to climate change. The effects of soil properties and climate on the SOC fractions in the mattic layer are not well understood. To address this, we analyzed the effects of environmental factors on two SOC fractions: particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). A random forest model (RFM), partial correlation analysis, and structural equation model (SEM) were used to quantify the relative effects of soil and climatic factors on SOC fractions. We found that SOC and its fractions are primarily regulated by soil properties rather than climate. Partial correlation analysis and SEM revealed that climate indirectly affects SOC by influencing soil properties. Silt+Clay and exchangeable calcium (Caex) were found to be the strongest contributing factors of MAOC and POC, respectively. A distinct shift occurs in the mechanism underlying SOC stabilization with varying soil pH. In acidic and neutral environments, amorphous Al/Fe-(hydr) oxides contribute to the stability of MAOC, whereas free Al/Fe-(hydr) oxides promote SOC mineralization. Conversely, Caex positively influences the stabilization of both POC and MAOC throughout the pH range. These results can be extrapolated to predict SOC dynamics in future soil conditions affected by environmental change, especially for use in Earth system models.

Size, distribution, and vulnerability of the global soil inorganic carbon.

Global estimates of the size, distribution, and vulnerability of soil inorganic carbon (SIC) remain largely unquantified. By compiling 223,593 field-based measurements and developing machine-learning models, we report that global soils store 2305 ± 636 (±1 SD) billion tonnes of carbon as SIC over the top 2-meter depth. Under future scenarios, soil acidification associated with nitrogen additions to terrestrial ecosystems will reduce global SIC (0.3 meters) up to 23 billion tonnes of carbon over the next 30 years, with India and China being the most affected. Our synthesis of present-day land-water carbon inventories and inland-water carbonate chemistry reveals that at least 1.13 ± 0.33 billion tonnes of inorganic carbon is lost to inland-waters through soils annually, resulting in large but overlooked impacts on atmospheric and hydrospheric carbon dynamics.

Synergy of de-walled Ganoderma Lucidum spore powder (GLSP) on targeted therapy in advanced non-squamous non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutant: protocol for a randomized, double-blind, placebo-controlled study.

BACKGROUND: Osimertinib is regarded as a promising third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) for advanced non-squamous non-small cell lung cancer (NSCLC) patients who developed T790M. However the adverse effects, primarily fatigue, remain an overwhelming deficiency of Osimertinib, hindering it from achieving adequate clinical efficacy for such NSCLC. Ganoderma lucidum has been used for thousands of years in China to combat fatigue, while Ganoderma Lucidum spores powder (GLSP) is the main active ingredient. The aim of this study is to investigate whether GLSP is sufficiently effective and safe in improving fatigue and synergizing with Osimertinib in non-squamous NSCLC patients with EGFR mutant. METHOD/DESIGN: A total of 140 participants will be randomly assigned to receive either de-walled GSLP or placebo for a duration of 56 days. The primary outcome measure is the fatigue score associated with EGFR-TKI adverse reactions at week 8, evaluated by the Chinese version of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire for Cancer Patients (QLQ-C30). Secondary outcomes include evaluation of treatment effectiveness, assessment of quality of life (QoL), and exploration of immune indicators and gut microbiota relationships. Following enrollment, visits are scheduled biweekly until week 12. TRIAL REGISTRATION: China Clinical Trial Registry ChiCTR2300072786. Registrated on June 25, 2023.

Nitrate leaching characteristics of red soils from different parent materials in subtropical China.

Globally, nitrate (NO3-) leaching from agroecosystems has been of major concern. There is evidence that NO3- leaching exhibits intense seasonal variation in subtropical regions. However, influencing factors to the seasonal dynamics remain unclear. In this study, a two-year field lysimeters experiment was conducted with three red soils derived from different parent materials (Quaternary red clay (QR), red sandstone (RS), and basalt (BA)). An N fertilizer (15N-enriched urea, 10 atom% excess) of 200 kg N ha-1 yr-1 was applied for maize. The effect of parent material on NO3- leaching characteristics was examined in surface (0-20 cm) and subsoil (20-100 cm) layers. The results showed due to the weakening of abundant drainage, there was no significant effect of parent materials on NO3- leaching characteristics in surface layers. Environmental factors (precipitation and temperature) and fertilization together led to obvious seasonal characteristics, i.e. abundant NO3- leaching during both crop growth and fallow periods. In subsoil layers, NO3- leaching characteristics were completely different among three soils. The concentrations and δ15N of NO3- in QR and RS soils showed a continuous increase after first year's fertilization, while those in BA soil remained relatively stable after reaching peak levels around harvest in first year. Meanwhile, the NO3- leaching amount in BA soil was significantly lower than in the other two soils. These might be explained by different NO3- adsorption capacities caused by the differences in mineral composition and free iron and aluminium contents. These elucidated in subsoil layers, NO3- leaching characteristics highly depended on parent materials. Meanwhile, adsorption capacity was limited and cannot slow NO3- leaching in the long run. Our results suggest that seasonal variation of NO3- leaching in surface layers and temporary retardant effect from NO3- adsorption capacity in subsoil layers should receive much attention when calculating and predicting NO3- leaching in subtropical regions.

Pervasive soil phosphorus losses in terrestrial ecosystems in China.

Future phosphorus (P) shortages could seriously affect terrestrial productivity and food security. We investigated the changes in topsoil available P (AP) and total P (TP) in China's forests, grasslands, paddy fields, and upland croplands during the 1980s-2010s based on substantial repeated soil P measurements (63,220 samples in the 1980s, 2000s, and 2010s) and machine learning techniques. Between the 1980s and 2010s, total soil AP stock increased with a small but significant rate of 0.13 kg P ha-1 year-1 , but total soil TP stock declined substantially (4.5 kg P ha-1 year-1 ) in the four ecosystems. We quantified the P budgets of soil-plant systems by harmonizing P fluxes from various sources for this period. Matching trends of soil contents over the decades with P budgets and fluxes, we found that the P-surplus in cultivated soils (especially in upland croplands) might be overestimated due to the great soil TP pool compared to fertilization and the substantial soil P losses through plant uptake and water erosion that offset the P additions. Our findings of P-deficit in China raise the alarm on the sustainability of future biomass production (especially in forests), highlight the urgency of P recycling in croplands, and emphasize the critical role of country-level basic data in guiding sound policies to tackle the global P crises.

Serological response and immune-related adverse events following COVID-19 vaccination in cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis.

With the popularity of Coronavirus disease 2019 (COVID-19) vaccine and the development of vaccination strategies, the impact of COVID-19 vaccine on cancer patients receiving immune checkpoint inhibitors (ICIs) is still unclear. In the systematic review and meta-analysis of patients with ICIs, we assessed the serological response of cancer patients receiving COVID-19 vaccine, and explored the risk of immune related adverse events (irAEs). We searched PubMed, EMBASE and Cochrane Library as of 10 June 2023, and included cancer patients who received ICIs and COVID-19 vaccine. The systematic review and meta-analysis include cohort study, cross-sectional study and case report. The outcome included the serological response, Spike-specific T-cell response, irAEs and rare adverse events. When possible, the data were analysed by random effect analysis, and the statistical heterogeneity was assessed by Q-test and I2 statistics. We explored the sources of heterogeneity through L'Abbe plots, Galbraith radial plots, and sensitivity analysis. The publication bias was evaluated by Egger's, Begg's linear regression test and funnel plot, and the impact of publication bias was further analysed by trim and fill method. 27 studies were eligible (19 cohort studies, 1 cross-sectional study and 7 case reports), involving 8331 patients (with 4724 receiving ICIs). Most studies used mRNA vaccine (BNT162b2 or mRNA-1273). Compared with cancer patients receiving chemotherapy, cancer patients receiving ICIs were significantly more likely to have seroconversion (RR = 1.05, 95%CI 1.01-1.10, P = 0.02). There were no statistically significant differences in seroconversion rates when comparing cancer patients receiving ICIs with controls without cancer (RR = 0.95, 95% CI 0.89-1.01, P = 0.09) or with cancer patients receiving targeted therapy (RR = 1.05, 95% CI 0.79-1.39, P = 0.75). The incidence of irAEs in patients receiving ICIs before and after COVID-19 vaccination was (21.96%, 95%CI 16.66%-28.94%) and (14.88%, 95%CI 8.65%-25.57%), respectively. The most common irAEs were endocrine abnormalities, skin disorders, etc. The certainty of evidence was low in cancer patients with ICIs, compared with those receiving chemotherapy, and very low versus controls without cancer. Cancer patients treated with ICIs seem to be able to receive COVID-19 vaccine safely without increasing the incidence of irAEs.

Compound Kushen injection combined with transarterial chemoembolization for hepatocellular carcinoma: An evidence map and overview of systematic reviews.

ETHNOPHARMACOLOGICAL RELEVANCE: For the treatment of hepatocellular carcinoma (HCC), compound Kushen injection (CKi) is commonly used in combination with transarterial chemoembolization (TACE). AIMS OF THE STUDY: Our objective was to evaluate the reporting quality, methodological quality, risk of bias, and certainty of evidence for CKi combined with TACE for the treatment of patients with HCC by conducting systematic reviews (SRs). The purpose of this study was to improve the clinical application of CKis, strengthen clinical decision-making regarding CKis, and inform future research. MATERIALS AND METHODS: We used eight databases to systematically search SRs of CKi combined with TACE for HCC through February 21, 2023. The quality of reporting of SRs was evaluated using the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, methodological quality using A MeaSurement Tool to Assess systematic Reviews 2, risk of bias using the Risk of Bias in Systematic Review, and certainty of evidence using the Grading of Recommendations Assessment. Finally, the assessment results were visualized by the evidence mapping method. This overview has been registered on PROSPERO with the registration title "Compound Kushen injection for hepatocellular carcinoma: An overview of systematic reviews" and registration number CRD42022369120. RESULTS: A total of 12 SRs meeting the inclusion criteria were included. In terms of reporting quality, 42% of SRs reported relatively complete reports and 58% had certain deficiencies. The methodological quality of all SRs was " critically low". The risk of bias was evaluated as low in 33% of SRs and high in 67% of SRs. The results of the evidence synthesis showed that, in the "moderate" level of evidence, CKi combined with TACE resulted in a 12.7%-21.5% benefit for one-year survival rate, 11.7%-17.2% benefit for objective response rate (ORR), 20.5%-27.1% benefit for quality of life, 22.2% benefit for nausea and vomiting, and 24.7%-27.4% benefit for leukopenia in HCC patients. CONCLUSION: In conclusion, CKi combined with TACE improved survival, ORR and quality of life in patients with HCC, and reduced adverse events. The results should be interpreted with caution due to the low methodological quality of the included SRs. The clinical efficacy of CKis must be confirmed in a large number of randomized controlled trials.

Tumor cell-induced platelet aggregation accelerates hematogenous metastasis of malignant melanoma by triggering macrophage recruitment.

BACKGROUND: Tumor cell-induced platelet aggregation (TCIPA) is not only a recognized mechanism for paraneoplastic thrombocytosis but also a potential breakthrough alternative for a low response to immune checkpoint inhibitors (ICIs) in hematogenous metastasis of malignant melanoma (MM). However, there is no TCIPA-specific model for further investigation of the relationship among TCIPA, the tumor immune microenvironment (TIME), and metastasis. METHODS: We developed a TCIPA metastatic melanoma model with advanced hematogenous metastasis and enhanced TCIPA characteristics. We also investigated the pathway for TCIPA in the TIME. RESULTS: We found that TCIPA triggers the recruitment of tumor-associated macrophages (TAMs) to lung metastases by secreting B16 cell-educated platelet-derived chemokines such as CCL2, SDF-1, and IL-1ß. Larger quantities of TAMs in the TCIPA model were polarized to the M2 type by B16 cell reprocessing, and their surface programmed cell death 1 ligand 1 (PD-L1) expression was upregulated, ultimately assisting B16 cells in escaping host immunity and accelerating MM hematogenous metastasis. CONCLUSIONS: TCIPA accelerates MM lung metastasis via tumor-educated platelets (TEPs), triggering TAM recruitment, promoting TAM polarization (M2), and remodeling the suppressive TIME in lung metastases.

Comprehensive analysis of resistance mechanisms to EGFR-TKIs and establishment and validation of prognostic model.

PURPOSE: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the first-line therapy for patients with lung adenocarcinoma (LUAD) harboring activating EGFR mutations. However, the emergence of drug resistance to EGFR-TKIs remains a critical obstacle for successful treatment and is associated with poor patient outcomes. The overarching objective of this study is to apply bioinformatics tools to gain insights into the mechanisms underlying resistance to EGFR-TKIs and develop a robust predictive model. METHODS: The genes associated with gefitinib resistance in the LUAD cell Gene Expression Omnibus (GEO) database were identified using gene chip expression data. Functional enrichment analysis, gene set enrichment analysis (GSEA), and immune infiltration analysis were performed to comprehensively explore the mechanism of gefitinib resistance. Furthermore, a GRRG_score was constructed by integrating genes related to LUAD prognosis from The Cancer Genome Atlas (TCGA) database with the screened Gefitinib Resistant Related differentially expressed genes (GRRDEGs) using the Least Absolute Shrinkage and Selection Operator (LASSO) and Cox regression analyses. Furthermore, we conducted an in-depth analysis of the tumor microenvironment (TME) features and their association with immune infiltration between different GRRG_score groups. A prognostic model for LUAD was developed based on the GRRG_score and validated. The HPA database was used to validate protein expression. The CTR-DB database was utilized to validate the results of drug therapy prediction based on the relevant genes. RESULTS: A total of 110 differentially expression genes were identified. Pathway enrichment analysis of DEGs showed that the differentially expressed genes were mainly enriched in Mucin type O-glycan biosynthesis, Cytokine-cytokine receptor interaction, Sphingolipid metabolism. Gene set enrichment analysis showed that biological processes strongly correlated with gefitinib resistance were cell proliferation and immune-related pathways, EPITHELIAL_MESENCHYMAL_TRANSITION, APICAL_SURFACE, and APICAL_JUNCTION were highly expressed in the drug-resistant group; KRAS_SIGNALING_DN, HYPOXIA, and HEDGEHOG_SIGNALING were highly expressed in the drug-resistant group. The GRRG_score was constructed based on the expression levels of 13 genes, including HSPA2, ATP8B3, SPOCK1, EIF6, NUP62CL, BCAR3, PCSK9, NT5E, FLNC, KRT8, FSCN1, ANGPTL4, and ID1. We further screened and validated two key genes, namely, NUP62CL and KRT8, which exhibited predictive value for both prognosis and drug resistance. CONCLUSIONS: Our study identified several novel GRRDEGs and provided insight into the underlying mechanisms of gefitinib resistance in LUAD. Our results have implications for developing more effective treatment strategies and prognostic models for LUAD patients.

Soil acidification in a tailing area of ionic rare earth in Southeast China.

Ionic rare earth ores are now commonly mined using the ammonium sulfate in situ leaching method, causing soil acidification in tailings. To evaluate the degree of soil acidification in tailings and the influence of mining activities on acidification, we selected an ionic rare earth tailing and a nearby unmined area in Southeast China. This tailing had been closed for 12 years. We sampled the soil from the surface to the bedrock in layers and determined soil properties related to soil acidification. The results showed that the average soil pH was 5.0 in the unmined area and 4.5 in the mined area (tailing area). Rare earth mining led to a decrease in soil pH of 0.47 units per 10 years, which was 2-5 times higher than that of other land uses. The shallow soil acidification in the mined area is not affected by mining. Deep soils were significantly acidified and the H+ concentration in the soil solution was approximately nine times that of the unmined area soil. Deep soil acidification is influenced very little by natural factors. The average soil ammonium­nitrogen (NH4+-N) and nitrate­nitrogen contents in the mined area were 58.34 mg kg-1 and 8.19 mg kg-1, respectively, 84 times and 21 times that of the unmined area. There were large amounts of NH4+, NO3-, and H+ in the soil of the mined area, indicating that soil acidification is closely related to exogenous NH4+-N input and nitrogen transformation. Nitrification is the most important driver of soil acidification in mining areas. Continued nitrification of excess NH4+-N will continue to produce H+ and migrate with water, which will cause long-term harm to the soil and surrounding environment in the mining area. Therefore, it is necessary to remove the enriched NH4+-N in tailings soil to avoid further soil acidification.

Histopathological growth pattern evolution of tumor in VX2 liver cancer model.

The histopathological growth pattern (HGP) is a morphological reflection of interactions between cancer cells and the surrounding tissue, and has been identified with a remarkably predictive value in liver metastases. However, there is still a lack of studies on HGP of primary liver cancer even furtherly on HGP evolution. We employed VX2 tumor-bearing rabbits as the primary liver cancer model of which tumor size and distant metastasis were investigated. HGP assessment and computed tomography scanning was performed in four cohorts of different time points to map the HGP evolution. Additionally, Fibrin deposition and neovascularization were evaluated by Masson staining and immunohistochemical analysis of CD31, hypoxia-inducible factor-1 alpha (HIF1A) and vascular endothelial growth factor (VEGF). Tumors displayed exponential growth in the VX2 liver cancer model, but these tumor-bearing animals did not show any visible metastasis until they reached a specific stage of development. Correspondingly, the components of HGPs changed along with the tumor growth. The proportion of desmoplastic HGP (dHGP) decreased initially and then grew, but in contrast, the level of replacement HGP (rHGP) rose from the 7th day, reached a peak at around the 21st day, and then appeared drop. Importantly, the collagen deposition and expression of HIF1A and VEGF correlated with dHGP, while CD31 did not. HGP evolution presents a two-way switch including dHGP to rHGP and rHGP to dHGP, in which the emergence of rHGP may be linked to metastases. HIF1A-VEGF partially participates in the HGP evolution and presumably plays a key role in the formation of dHGP.

JDHY3 Inhibits Hypopharyngeal Carcinoma Cell Proliferation and Promotes Apoptosis by Inhibiting the PI3K/AKT Pathway.

BACKGROUND: Jieduhuayu No.3 (JDHY3) is a modified Chinese herbal formula beneficial for treating hypopharyngeal carcinoma (HC), but its pharmacological mechanism is unknown. OBJECTIVE: This study aimed to explore the mechanism of the herbal formula JDHY3 in inhibiting cell proliferation and promoting apoptosis in HC in vitro and in vivo. METHODS: In this study, HC cells were treated with cisplatin and different concentrations of JDHY3. The apoptosis rate was detected by flow cytometry. Western blotting was used to detect the proteins related to cell proliferation and apoptosis. Afterward, the xenograft mouse model was established and treated with cisplatin and JDHY3. Mouse tumour volume was measured, and the tumour tissues were assessed by HE staining and immunohistochemistry. RESULTS: JDHY3 significantly inhibited the proliferation of FaDu and Detroit-562 cells. In addition, JDHY3 significantly increased the apoptosis rate of HC cells and downregulated p-PI3K and p-Akt. In addition, JDHY3 upregulated the expression of the apoptosis-promoting proteins Bax, P53, and cleaved caspase-3. In addition, the expression of the antiapoptotic protein Bcl-2 was downregulated. Coincubation with SC79 attenuated the decrease in cell proliferation induced by JDHY3, further confirming that the proapoptotic effect of JDHY3 is associated with the inhibition of PI3K/Akt pathway activation. CONCLUSIONS: The results of in vivo experiments showed that JDHY3 could effectively inhibit the proliferation of HC cells, and HE staining showed that JDHY3 reduced the invasion of HC cells. Immunohistochemistry showed that the expression of P53 and cleaved caspase-3 was significantly increased in the tissues of the JDHY3-treated group.

Deep accumulation of soluble organic nitrogen after land-use conversion from woodlands to orchards in a subtropical hilly region.

Accumulation of soluble organic nitrogen (SON) in soil poses a significant threat to groundwater quality and plays an important role in regulating the global nitrogen cycle; however, most related studies have focused only on the upper 100-cm soil layers. Surface land-use management and soil properties may affect the vertical distribution of SON; however, their influence is poorly understood in deep soil layers. Therefore, this study assessed the response of SON concentration, pattern, and storage in deep regoliths to land-use conversion from woodlands to orchards in a subtropical hilly region. Our results showed that the SON stocks of the entire soil profile (up to 19.5 m) ranged from 254.5 kg N ha-1 to 664.1 kg N ha-1. Land-use conversion not only reshaped the distribution pattern of SON, but also resulted in substantial accumulation of SON at the 0-200 cm soil profile in the orchards compared to that in the woodlands (124.1 vs 190.5 kg N ha-1). Land-use conversion also altered the SON/total dissolved nitrogen ratio throughout the regolith profile, resulting in a relatively low (<50 %) ratio in orchard soils below 200 cm. Overall, 76.8 % of SON (338.4 ± 162.0 kg N ha-1) was stored in the layers from 100 cm below the surface to the bedrock. Regolith depth (r = -0.52 and p < 0.05) was found to be significantly correlated with SON concentration, explaining 17.8 % of the variation in SON, followed by total nitrogen (14.4 %), total organic carbon/total nitrogen ratio (10.1 %), and bulk density (9.3 %). This study provides insights into the estimation of terrestrial nitrogen and guidance for mitigation of groundwater contamination risk due to deep accumulation of SON.

Soil organic carbon content increase in the east and south of China is accompanied by soil acidification.

Increased soil organic carbon (OC) in China has been reported in the past two decades, suggesting the sequestration of atmospheric carbon dioxide into soil, mitigating climate change and improving soil health. On the other hand, soil pH decrease had also been reported nationwide. If the two are related, the strategy of increasing soil OC could negatively affect soil quality for food production and the environment. We investigate this thread based on large-scale soil survey data from two provinces with typical soil and cropping patterns in the east and south of China, Jiangsu (102,600 km2) and Guangdong (177,900 km2). The data include >5000 observations from soil surveys conducted over the past four decades, i.e., the 1980s, 2006-2007, and 2010-2011. Using spatiotemporal modelling, we show that across Jiangsu province, the topsoil OC on average has increased from 8.5 g kg-1 to 9.9 g kg-1 from 1980 to 2000 and a further increase to 12.6 g kg-1 in 2010. This increase was accompanied by a decrease in average pH from 7.63 to 6.90. In Guangdong, there was an overall increase in average topsoil OC content from 14.2 g kg-1, 16.5 g kg-1, and 20.2 g kg-1 with a decrease in average pH from 5.58, 4.90, and 4.98. Based on the spatiotemporal modelling results, the structural equation modelling analysis shows that OC and pH changes were significantly correlated and linked by increased soil N content. On croplands, soil N content was mainly attributed to N fertiliser application. The pH decrease was particularly significant in the east of China where the soils were neutral in pH. We recommend that more revolutionary means be taken to sequestrate atmospheric carbon into soil as the current OC increase due to increasing crop productivity via a high rate of nitrogen application may have a potential acidification effect.