Integrative single-cell analysis of longitudinal t(8;21) AML reveals heterogeneous immune cell infiltration and prognostic signatures.

Introduction: Immunotherapies targeting T cells in solid cancers are revolutionizing clinical treatment. Novel immunotherapies have had extremely limited benefit for acute myeloid leukemia (AML). Here, we characterized the immune microenvironment of t(8;21) AML patients to determine how immune cell infiltration status influenced prognosis. Methods: Through multi-omics studies of primary and longitudinal t(8;21) AML samples, we characterized the heterogeneous immune cell infiltration in the tumor microenvironment and their immune checkpoint gene expression. Further external cohorts were also included in this research. Results: CD8+ T cells were enriched and HAVCR2 and TIGIT were upregulated in the CD34+CD117dim%-High group; these features are known to be associated with immune exhaustion. Data integration analysis of single-cell dynamics revealed that a subset of T cells (cluster_2) (highly expressing GZMB, NKG7, PRF1 and GNLY) evolved and expanded markedly in the drug-resistant stage after relapse. External cohort analysis confirmed that the cluster_2 T-cell signature could be utilized to stratify patients by overall survival outcome. Discussion: In conclusion, we discovered a distinct T-cell signature by scRNA-seq that was correlated with disease progression and drug resistance. Our research provides a novel system for classifying patients based on their immune microenvironment.

Enhancement of gemcitabine sensitivity in intrahepatic cholangiocarcinoma through Saikosaponin-a mediated modulation of the p-AKT/BCL-6/ABCA1 axis.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) remains a significant challenge in cancer therapy, especially due to its resistance to established treatments like Gemcitabine, necessitating novel therapeutic approaches. METHODS: This study utilized Gemcitabine-resistant cell lines, patient-derived organotypic tumor spheroids (PDOTs), and patient-derived xenografts (PDX) to evaluate the effects of Saikosaponin-a (SSA) on ICC cellular proliferation, migration, apoptosis, and its potential synergistic interaction with Gemcitabine. Techniques such as transcriptome sequencing, Luciferase reporter assays, and molecular docking were employed to unravel the molecular mechanisms. RESULTS: SSA exhibited antitumor effects in both in vitro and PDX models, indicating its considerable potential for ICC treatment. SSA markedly inhibited ICC progression by reducing cellular proliferation, enhancing apoptosis, and decreasing migration and invasion. Crucially, it augmented Gemcitabine's efficacy by targeting the p-AKT/BCL6/ABCA1 signaling pathway. This modulation led to the downregulation of p-AKT and suppression of BCL6 transcriptional activity, ultimately reducing ABCA1 expression and enhancing chemosensitivity to Gemcitabine. Additionally, ABCA1 was validated as a predictive biomarker for drug resistance, with a direct correlation between ABCA1 expression levels and the IC50 values of various small molecule drugs in ICC gene profiles. CONCLUSION: This study highlights the synergistic potential of SSA combined with Gemcitabine in enhancing therapeutic efficacy against ICC and identifies ABCA1 as a key biomarker for drug responsiveness. Furthermore, the introduction of the novel PDOTs microfluidic model provides enhanced insights into ICC research. This combination strategy may provide a novel approach to overcoming treatment challenges in ICC.

Intraplatelet miRNA-126 regulates thrombosis and its reduction contributes to platelet inhibition.

AIMS: MicroRNA-126 (miR-126), one of the most abundant microRNAs in platelets, is involved in the regulation of platelet activity and the circulating miR-126 is reduced during antiplatelet therapy. However, whether intraplatelet miR-126 plays a role in thrombosis and platelet inhibition remains unclear. METHODS AND RESULTS: Here, using tissue-specific knockout mice, we reported that the deficiency of miR-126 in platelets and vascular endothelial cells significantly prevented thrombosis and prolonged bleeding time. Using chimeric mice, we identified that the lack of intraplatelet miR-126 significantly prevented thrombosis. Ex vivo experiments further demonstrated that miR-126-deficient platelets displayed impaired platelet aggregation, spreading and secretory functions. Next, miR-126 was confirmed to target phosphoinositol-3 kinase regulatory subunit 2 (PIK3R2) in platelet, which encodes a negative regulator of the PI3 K/AKT pathway, enhancing platelet activation through activating the integrin αIIbß3-mediated outside-in signaling. After undergoing myocardial infarction (MI), chimeric mice lacking intraplatelet miR-126 displayed reduced microvascular obstruction and prevented MI expansion in vivo. In contrast, overexpression of miR-126 by the administration of miR-126 agonist (agomiR-126) in wild-type mice aggravated microvascular obstruction and promoted MI expansion, which can be almost abolished by aspirin administration. In patients with cardiovascular diseases, antiplatelet therapies, either aspirin alone or combined with clopidogrel, decreased the level of intraplatelet miR-126. The reduction of intraplatelet miR-126 level was associated with the decrease of platelet activity. CONCLUSIONS: Our murine and human data reveal that (i) intraplatelet miR-126 contributes to platelet activity and promotes thrombus formation, and (ii) the reduction of intraplatelet miR-126 contributes to platelet inhibition during antiplatelet therapy.

Dichotomous roles of ADAR1 in liver hepatocellular carcinoma and kidney renal cell carcinoma: Unraveling the complex tumor microenvironment and prognostic significance.

BACKGROUND: Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA-editing enzyme that significantly impacts cancer progression and various biological processes. The expression of ADAR1 mRNA has been examined in multiple cancer types using The Cancer Genome Atlas (TCGA) dataset, revealing distinct patterns in kidney chromophobe (KICH), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), and liver hepatocellular carcinoma (LIHC) compared to normal controls. However, the reasons for these differential expressions remain unclear. METHODS: In this study, we performed RT-PCR and western blotting (WB) to validate ADAR1 expression patterns in clinical tissue samples. Survival analysis and immune microenvironment analysis (including immune score and stromal score) were conducted using TCGA data to determine the specific cell types associated with ADAR1, as well as the key genes in those cell types. The relationship between ADAR1 and specific cell types' key genes was verified by immunohistochemistry (IHC), using clinical liver and kidney cancer samples. RESULTS: Our validation analysis revealed that ADAR1 expression was downregulated in KICH, KIRC, and KIRP, while upregulated in LIHC compared to normal tissues. Notably, a significant correlation was found between ADAR1 mRNA expression and patient prognosis, particularly in KIRC, KIRP, and LIHC. Interestingly, we observed a positive correlation between ADAR1 expression and stromal scores in KIRC, whereas a negative correlation was observed in LIHC. Cell type analysis highlighted distinct relationships between ADAR1 expression and the two stromal cell types, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs), and further determined the signature gene claudin-5 (CLDN5), in KIRC and LIHC. Moreover, ADAR1 was inversely related with CLDN5 in KIRC (n = 26) and LIHC (n = 30) samples, verified via IHC. CONCLUSIONS: ADAR1 plays contrasting roles in LIHC and KIRC, associated with the enrichment of BECs and LECs within tumors. This study sheds light on the significant roles of stromal cells within the complex tumor microenvironment (TME) and provides new insights for future research in tumor immunotherapy and precision medicine.

Multifaceted roles of lymphatic and blood endothelial cells in the tumor microenvironment of hepatocellular carcinoma: A comprehensive review.

The tumor microenvironment is a complex network of cells, extracellular matrix, and signaling molecules that plays a critical role in tumor progression and metastasis. Lymphatic and blood vessels are major routes for solid tumor metastasis and essential parts of tumor drainage conduits. However, recent studies have shown that lymphatic endothelial cells (LECs) and blood endothelial cells (BECs) also play multifaceted roles in the tumor microenvironment beyond their structural functions, particularly in hepatocellular carcinoma (HCC). This comprehensive review summarizes the diverse roles played by LECs and BECs in HCC, including their involvement in angiogenesis, immune modulation, lymphangiogenesis, and metastasis. By providing a detailed account of the complex interplay between LECs, BECs, and tumor cells, this review aims to shed light on future research directions regarding the immune regulatory function of LECs and potential therapeutic targets for HCC.

Utility of paired plasma and drainage fluid mNGS in diagnosing acute intra-abdominal infections with sepsis.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) has been increasingly applied in sepsis. We aimed to evaluate the diagnostic and therapeutic utility of mNGS of paired plasma and peritoneal drainage (PD) fluid samples in comparison to culture-based microbiological tests (CMTs) among critically ill patients with suspected acute intra-abdominal infections (IAIs). METHODS: We conducted a prospective study from October 2021 to December 2022 enrolling septic patients with suspected IAIs (n = 111). Pairwise CMTs and mNGS of plasma and PD fluid were sent for pathogen detection. The mNGS group underwent therapeutic regimen adjustment based on mNGS results for better treatment. The microbial community structure, clinical features, antibiotic use and prognoses of the patients were analyzed. RESULTS: Higher positivity rates were observed with mNGS versus CMTs for both PD fluid (90.0% vs. 48.3%, p < 0.005) and plasma (76.7% vs. 1.6%, p < 0.005). 90% of enrolled patients had clues of suspected pathogens combining mNGS and CMT methods. Gram-negative pathogens consist of most intra-abdominal pathogens, including a great variety of anaerobes represented by Bacteroides and Clostridium. Patients with matched plasma- and PD-mNGS results had higher mortality and sepsis severity. Reduced usage of carbapenem (30.0% vs. 49.4%, p < 0.05) and duration of anti-MRSA treatment (5.1 ± 3.3 vs. 7.0 ± 8.4 days, p < 0.05) was shown in the mNGS group in our study. CONCLUSIONS: Pairwise plasma and PD fluid mNGS improves microbiological diagnosis compared to CMTs for acute IAI. Combining plasma and PD mNGS could predict poor prognosis. mNGS may enable optimize empirical antibiotic use.

Impact factors and obstetric outcomes of preeclampsia in twin pregnancies by prepregnancy body mass index: a six-year retrospective cohort study.

OBJECTIVES: Among many risk factors for preeclampsia (PE), prepregnancy body mass index (BMI) is one of few controllable factors. However, there is a lack of stratified analysis based on the prepregnancy BMI. This study aimed to determine the influencing factors for PE and assess the impact of PE on obstetric outcomes in twin pregnancies by prepregnancy BMI. METHODS: This was a retrospective cohort study between January 1, 2017, and December 31, 2022, in Southwest China. Impact factors and associations between PE and obstetric outcomes were analyzed separately for twin pregnancies with prepregnancy BMI < 24kg/m2 (non-overweight group) and BMI ≥ 24kg/m2 (overweight group). RESULTS: In total, 3602 twin pregnancies were included, of which, 672 women were allocated into the overweight group and 11.8% of them reported with PE; 2930 women were allocated into the non-overweight group, with a PE incidence of 5.6%. PE had a negative effect on birthweight and increased the incidence of neonatal intensive care unit admission in both the overweight and non-overweight groups (43.0% vs. 28.0%, p = .008; 45.7% vs. 29.1%, p < .001). Among overweight women, PE increased the proportion of postpartum hemorrhage (15.2% vs. 4.4%, p < .001). After adjustments, multivariate regression analysis showed that excessive gestational weight gain (aOR = 1.103, 95% CI: 1.056-1.152; aOR = 1.094, 95% CI: 1.064-1.126) and hypoproteinemia (aOR = 2.828, 95% CI: 1.501-5.330; aOR = 6.932, 95% CI: 4.819-9.971) were the shared risk factors for PE in both overweight and non-overweight groups. In overweight group, in vitro fertilization was the other risk factor (aOR = 2.713, 95% CI: 1.183-6.878), whereas dichorionic fertilization (aOR = 0.435, 95% CI: 0.193-0.976) and aspirin use during pregnancy (aOR = 0.456, 95% CI: 0.246-0.844) were protective factors. Additionally, anemia during pregnancy (aOR = 1.542, 95% CI: 1.090-2.180) and growth discordance in twins (aOR = 2.451, 95% CI: 1.215-4.205) were connected with an increased risk of PE only in non-overweight twin pregnancies. CONCLUSIONS: Both discrepancy and similarity of impact factors on developing PE were found between overweight and non-overweight twin pregnancies in this study. However, the dosage and initiation time of aspirin, as well as twin chorionicity on the occurrence of PE in two subgroups, are still debated.

Human pluripotent stem cell (hPSC)-derived microglia for the study of brain disorders. A comprehensive review of existing protocols.

Microglia, resident immune cells of the brain that originate from the yolk sac, play a critical role in maintaining brain homeostasis by monitoring and phagocytosing pathogens and cellular debris in the central nervous system (CNS). While they share characteristics with myeloid cells, they are distinct from macrophages. In response to injury, microglia release pro-inflammatory factors and contribute to brain homeostasis through activities such as synapse pruning and neurogenesis. To better understand their role in neurological disorders, the generation of in vitro models of human microglia has become essential. These models, derived from patient-specific induced pluripotent stem cells (iPSCs), provide a controlled environment to study the molecular and cellular mechanisms underlying microglia-mediated neuroinflammation and neurodegeneration. The incorporation or generation of microglia into three-dimensional (3D) organoid cultures provides a more physiologically relevant environment that offers further opportunities to study microglial dynamics and disease modeling. This review describes several protocols that have been recently developed for the generation of human-induced microglia. Importantly, it highlights the promise of these in vitro models in advancing our understanding of brain disorders and facilitating personalized drug screening.

Transcription-related metabolic regulation in grafted lemon seedlings under magnesium deficiency stress.

Magnesium is one of the essential nutrients for plant growth, and plays a pivotal role in plant development and metabolism. Soil magnesium deficiency is evident in citrus production, which ultimately leads to failure of normal plant growth and development, as well as decreased productivity. Citrus is mainly propagated by grafting, so it is necessary to fully understand the different regulatory mechanisms of rootstock and scion response to magnesium deficiency. Here, we characterized the differences in morphological alterations, physiological metabolism and differential gene expression between trifoliate orange rootstocks and lemon scions under normal and magnesium-deficient conditions, revealing the different responses of rootstocks and scions to magnesium deficiency. The transcriptomic data showed that differentially expressed genes were enriched in 14 and 4 metabolic pathways in leaves and roots, respectively, after magnesium deficiency treatment. And the magnesium transport-related genes MHX and MRS2 may respond to magnesium deficiency stress. In addition, magnesium deficiency may affect plant growth by affecting POD, SOD, and CAT enzyme activity, as well as altering the levels of hormones such as IAA, ABA, GA3, JA, and SA, and the expression of related responsive genes. In conclusion, our research suggests that the leaves of lemon grafted onto trifoliate orange were more significantly affected than the roots under magnesium-deficient conditions, further indicating that the metabolic imbalance of scion lemon leaves was more severe.

Knowledge, attitudes and practices towards community-acquired pneumonia and COVID-19 among general population: a cross-sectional study.

BACKGROUND: This study aimed to assess the knowledge, attitudes, and practices (KAP) of the general population to community-acquired pneumonia (CAP) and COVID-19. METHODS: A cross-sectional study was conducted between September 2022 and February 2023, involving the general population from Ningbo Municipal Hospital of Traditional Chinese Medicine with a self-developed questionnaire. RESULTS: A total of 637 valid questionnaires were collected, with the majority of participants being female (62.48%). The mean score for knowledge, attitudes, and practices were 7.60 ± 2.39 (possible range: 0-12), 43.20 ± 4.57 (possible range: 11-55), and 34.57 ± 4.95 (possible range: 10-50), respectively. Multivariate logistic regression analysis indicated that master's degree or above (OR = 6.04, 95% CI: 1.80-20.31, P = 0.004) and occupation in business or service careers (OR = 0.28, 95% CI: 0.17-0.48, P < 0.001) were independent associated with knowledge. The knowledge (OR = 1.32, 95%CI: 1.20-1.44, P < 0.001) and female gender (OR = 1.48, 95%CI: 1.03-2.14, P = 0.036) were independently associated with positive attitudes. Attitudes (OR = 1.34, 95%CI: 1.26-1.43, P < 0.001) and a monthly household income greater than 20,000 RMB (OR = 0.31, 95%CI: 0.15-0.64, P = 0.001) were independent associated with practices. Pearson correlation analysis revealed that knowledge positively correlated with attitude scores (r = 0.348, P < 0.001) and practice scores (r = 0.259, P < 0.001), and attitude and practice scores were also positively correlated (r = 0.563, P < 0.001). Structural equation modeling showed that knowledge predicted attitudes (ß = 0.67, P < 0.001) and practices (ß = 0.17, P = 0.017), while attitudes predicted practices (ß = 0.58, P < 0.001). CONCLUSION: General population had moderate knowledge, positive attitudes and average practices towards CAP and COVID-19.

DZ2002 alleviates corneal angiogenesis and inflammation in rodent models of dry eye disease via regulating STAT3-PI3K-Akt-NF-κB pathway.

Dry eye disease (DED) is a prevalent ocular disorder with a multifactorial etiology. The pre-angiogenic and pre-inflammatory milieu of the ocular surface plays a critical role in its pathogenesis. DZ2002 is a reversible type III S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitor, which has shown excellent anti-inflammatory and immunosuppressive activities in vivo and in vitro. In this study, we evaluated the therapeutic potential of DZ2002 in rodent models of DED. SCOP-induced dry eye models were established in female rats and mice, while BAC-induced dry eye model was established in female rats. DZ2002 was administered as eye drops (0.25%, 1%) four times daily (20 µL per eye) for 7 or 14 consecutive days. We showed that topical application of DZ2002 concentration-dependently reduced corneal neovascularization and corneal opacity, as well as alleviated conjunctival irritation in both DED models. Furthermore, we observed that DZ2002 treatment decreased the expression of genes associated with angiogenesis and the levels of inflammation in the cornea and conjunctiva. Moreover, DZ2002 treatment in the BAC-induced DED model abolished the activation of the STAT3-PI3K-Akt-NF-κB pathways in corneal tissues. We also found that DZ2002 significantly inhibited the proliferation, migration, and tube formation of human umbilical endothelial cells (HUVECs) while downregulating the activation of the STAT3-PI3K-Akt-NF-κB pathway. These results suggest that DZ2002 exerts a therapeutic effect on corneal angiogenesis in DED, potentially by preventing the upregulation of the STAT3-PI3K-Akt-NF-κB pathways. Collectively, DZ2002 is a promising candidate for ophthalmic therapy, particularly in treating DED.

Sperm retrieval outcomes of contralateral testis in men with nonobstructive azoospermia and unsuccessful unilateral microdissection testicular sperm extraction.

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How does economic inequality shape conspiracy theories? Empirical evidence from China.

Conspiracy theories tend to be prevalent, particularly in societies with high economic inequality. However, few studies have examined the relationship between economic inequality and belief in conspiracy theories. We propose that economic inequality leads people to believe conspiracy theories about economically advantaged groups (i.e., upwards conspiracy theories) and that moral evaluations of those groups mediate this relationship. Study 1 (N = 300) found support for these ideas in a survey among Chinese residents. Study 2 (N = 160) manipulated participants' perceptions of economic inequality in a virtual society. The manipulation shaped moral evaluations of economically advantaged groups, and conspiracy beliefs, in the predicted manner. In Study 3 (N = 191) and Study 4 (N = 210), we experimentally manipulated participants' perceptions of economic inequality in real Chinese society and replicated the results of Study 2. In addition, in Study 4, we find that economic inequality predicts belief in conspiracy theories about economically disadvantaged groups (i.e., downward conspiracy theories), which was mediated by anomie. We conclude that perceived economic inequality predicts conspiracy theories about economically advantaged groups and that moral evaluations account for this effect. Also, upward and downward conspiracy theory beliefs are associated with different psychological processes.

A comprehensive evaluation of circ_0065214/ miR-188-3p/GPNMB axis in breast cancer.

CircRNAs are involved in multiple aspects during carcinogenesis, including tumorigenesis, vascularization, apoptosis and others. Exploring the role of circRNAs in breast cancer (BC) enables us to understand the development mechanism of BC more comprehensively. Here, we screened out and verified an up-regulated circRNA in BC from GEO data. Quantitative Real-time PCR (qRT-PCR) showed that circ_0065214 had a high expression level in BC patients. Besides, circ_0065214 had good diagnostic value in BC serum, and the area under the diagnostic curve, sensitivity and specificity were 0.78, 0.63 and 0.85, respectively. The combined application of circ_0065214 with CEA and CA-153 can further improve the diagnostic efficiency. The knockdown of circ_0065214 in vivo and in vitro inhibited the proliferation, migration and invasion of BC, but promoted autophagy. At last, dual-luciferase reporter assay and rescue assays revealed that circ_0065214 acted as a decoy to adsorb miR-188-3p, and then relieved the repressive effect of miR-188-3p on its target GPNMB. Our results demonstrated that circ_0065214 regulated the expression of GPNMB by competitively binding to miR-188-3p, thus promoting the proliferation, migration and invasion of breast cancer cells and inhibiting autophagy. These findings provided an original therapeutic strategy for BC.

Structures of nickel chloride and thiolate complexes supported by PCN and POCOP pincer ligands and catalytic reactivity of the chloride complexes.

Nickel chloride and thiolate complexes supported by benzene-pyridine-based nonsymmetrical PCN pincer ligands, [2-(tBu2PO)-6-(2-pyrindinyl-4-R)-C6H3]NiX (R = H, CH3, CF3; X = Cl, SH, SPh), were synthesized and fully characterized. The structures of these complexes and the catalytic reactivity of the chloride complexes were investigated along with the related POCOP counterparts [2,6-(tBu2PO)2C6H3]NiX (X = Cl, SH). It was found that the composition and substitution of the pincer backbone evidently influence the structures and catalytic reactivity. The Ni-P and Ni-Cipso bond lengths in the PCN complexes are significantly shorter than those in the POCOP complex. The Ni-Cl and Ni-S bond lengths in the PCN complexes are longer than those in the POCOP complexes. An electron rich pyrindinyl ring in the PCN complexes makes the Ni-Cl bond longer. The Ni-N bond length is more sensitive to the auxiliary ligand compared with the Ni-P bond length in the PCN complexes. The PCN chloride complexes were found to be active catalysts for selective hydration of nitriles to primary amides in the presence of NaOH at 80 °C and the catalytic activity increases with the increase of electron richness of the pyridinyl ring. However, the corresponding POCOP counterpart is inactive under the same conditions.

GPR65 inhibits human trophoblast cell adhesion through upregulation of MYLK and downregulation of fibronectin via cAMP-ERK signaling in a low pH environment.

BACKGROUND: Extravillous trophoblasts (EVTs) are essential cells during the formation of the placenta, with the major function of invading the maternal decidua, anchoring the developing placenta to the uterus, remodeling uterine arteries, and regulating immune responses to prevent rejection. During early pregnancy, the decidua undergoes a hypoxic and acidic microenvironment, which has been shown to participate in tumor cell migration, invasion, growth, and angiogenesis. Nevertheless, the mechanisms by which EVTs sense and respond to the acidic microenvironment, thereby executing their functions, remain poorly understood. METHODS: The effects of G protein-coupled receptor 65 (GPR65) on cell adhesion and other cellular functions were tested using JAR spheroids, mouse blastocysts, and HTR-8/SVneo cells. Specifically, we employed HTR-8/SVneo cells for gene overexpression and silencing to investigate the underlying mechanism of GPR65's impact on trophoblast cell function under acidic conditions. Additionally, villus tissue samples obtained from early pregnancy loss patients were utilized to explore the potential association between GPR65 and its related signaling pathway molecules with the disease. RESULTS: This study identified GPR65 expression widely in trophoblasts, with the highest level in EVTs. Importantly, optimal GPR65 levels are required for maintaining normal adhesion, migration, and invasion, whereas overexpression of GPR65 inhibits these functions by activating the cAMP-ERK signaling pathway, upregulating myosin light chain kinase (MYLK) and MYLK3 expression, and subsequently downregulating fibronectin. Consistently, elevated expression of GPR65, MYLK, and MYLK3 is observed in patients suffering from early pregnancy loss. CONCLUSIONS: This work offers insights into the suppressive effects of GPR65 on EVT function under acidic conditions and highlights a putative target for therapeutic intervention in early pregnancy complications. Video Abstract.

Regional differences in islet amyloid deposition in the residual pancreas with new-onset diabetes secondary to pancreatic ductal adenocarcinoma.

BACKGROUND: Islet amyloid deposition and reduced ß-cell mass are pathological hallmarks in type 2 diabetes mellitus subjects. To date, the pathological features of the islets in diabetes secondary to pancreatic ductal adenocarcinoma (PDAC) have not been specifically addressed. AIM: To provide further insight into the relationship between islet amyloid deposition of the residual pancreas in PDAC patients and to explore whether regional differences (proximal vs distal residual pancreas) are associated with islet amyloid deposition. METHODS: We retrospectively collected clinical information and pancreatic tissue removed from tumors of 45 PDAC patients, including 14 patients with normal glucose tolerance (NGT), 16 patients with prediabetes and 15 new-onset diabetes (NOD) patients diagnosed before surgery by an oral glucose tolerance test at West China Hospital from July 2017 to June 2020. Pancreatic volume was calculated by multiplying the estimated area of pancreatic tissue on each image slice by the interval between slices based on abdominal computer tomography scans. Several sections of paraffin-embedded pancreas specimens from both the proximal and/or distal regions remote from the tumor were stained as follows: (1) Hematoxylin and eosin for general histological appearance; (2) hematoxylin and insulin for the determination of fractional ß-cell area (immunohistochemistry); and (3) quadruple insulin, glucagon, thioflavin T and DAPI staining for the determination of ß-cell area, α-cell area and amyloid deposits. RESULTS: Screening for pancreatic histologic features revealed that duct obstruction with islet amyloid deposition, fibrosis and marked acinar atrophy were robust in the distal pancreatic regions but much less robust in the proximal regions, especially in the prediabetes and NOD groups. Consistent with this finding, the remnant pancreatic volume was markedly decreased in the NOD group by nearly one-half compared with that in the NGT group (37.35 ± 12.16 cm3 vs 69.79 ± 18.17 cm3, P < 0.001). As expected, islets that stained positive for amyloid (islet amyloid density) were found in the majority of PDAC cases. The proportion of amyloid/islet area (severity of amyloid deposition) was significantly higher in both prediabetes and NOD patients than in NGT patients (P = 0.002; P < 0.0001, respectively). We further examined the regional differences in islet amyloid deposits. Islet amyloid deposit density was robustly increased by approximately 8-fold in the distal regions compared with that in the proximal regions in the prediabetes and NOD groups (3.98% ± 3.39% vs 0.50% ± 0.72%, P = 0.01; 12.03% vs 1.51%, P = 0.001, respectively). CONCLUSION: In conclusion, these findings suggest that robust alterations of the distal pancreas due to tumors can disturb islet function and structure with islet amyloid formation, which may be associated with the pathogenesis of NOD secondary to PDAC.