Histone lactylation dynamics: Unlocking the triad of metabolism, epigenetics, and immune regulation in metastatic cascade of pancreatic cancer.

Cancer cells rewire metabolism to sculpt the immune tumor microenvironment (TME) and propel tumor advancement, which intricately tied to post-translational modifications. Histone lactylation has emerged as a novel player in modulating protein functions, whereas little is known about its pathological role in pancreatic ductal adenocarcinoma (PDAC) progression. Employing a multi-omics approach encompassing bulk and single-cell RNA sequencing, metabolomics, ATAC-seq, and CUT&Tag methodologies, we unveiled the potential of histone lactylation in prognostic prediction, patient stratification and TME characterization. Notably, "LDHA-H4K12la-immuno-genes" axis has introduced a novel node into the regulatory framework of "metabolism-epigenetics-immunity," shedding new light on the landscape of PDAC progression. Furthermore, the heightened interplay between cancer cells and immune counterparts via Nectin-2 in liver metastasis with elevated HLS unraveled a positive feedback loop in driving immune evasion. Simultaneously, immune cells exhibited altered HLS and autonomous functionality across the metastatic cascade. Consequently, the exploration of innovative combination strategies targeting the metabolism-epigenetics-immunity axis holds promise in curbing distant metastasis and improving survival prospects for individuals grappling with challenges of PDAC.

Human Equilibrative Nucleoside Transporter 1: Novel Biomarker and Prognostic Indicator for Patients with Gemcitabine-Treated Pancreatic Cancer.

Aim: This article aimed to find appropriate pancreatic cancer (PC) patients to treat with Gemcitabine with better survival outcomes by detecting hENT1 levels. Methods: We collected surgical pathological tissues from PC patients who received radical surgery in our hospital from September 2004 to December 2014. A total of 375 PC tissues and paired adjacent nontumor tissues were employed for the construction of 4 tissue microarrays (TMAs). The quality of the 4 TMAs was examined by HE staining. We performed immunohistochemistry analysis to evaluate hENT1 expression in the TMAs. Moreover, we detected hENT1 expression level and proved the role of hENT1 in cell proliferation, drug resistance, migration and invasion in vivo and vitro. Results: The results indicated that low hENT1 expression indicated a significantly poor outcome in PC patients, including shortened DFS (21.6±2.8 months versus 36.9±4.0 months, p<0.001) and OS (33.6±3.9 versus 39.6±3.9, p=0.004). Meanwhile, patients in stage I/II of TNM stage had a longer OS (40.2±3.4 versus 15.4±1.7, p=0.002) and DFS (31.0±3.1 versus 12.4±1.9, p=0.016) than patients in stage III/IV. Patients in M0 stage had a longer OS (39.7±3.4 versus 16.2±1.9, p=0.026) and DFS(30.7±3.0 versus 11.8±2.2, p=0.031) than patients in M1 stage, and patients with tumors not invading the capsule had a better DFS than those with tumor invasion into the capsule (30.8±3.0 versus 12.6±2.3, p=0.053). Patients with preoperative CA19-9 values ≤467 U/mL have longer DFS than that of patients who had preoperative CA19-9 values >467 U/mL (37.9±4.1 versus 22.9±4.0, p=0.04). In the subgroup analysis, a high hENT1 expression level was related to a longer OS(39.4±4.0 versus 31.5±3.9, p=0.001) and DFS(35.7±4.0 versus 20.6±2.7; p<0.0001) in the Gemcitabine subgroup. Conclusion: PC patients with high hENT1 expression have a better survival outcomes when receiving Gemcitabine. hENT1 expression can be a great prognostic indicator for PC patients to receive Gemcitabine treatment.

Comprehensive analysis of bulk and single-cell transcriptomic data reveals a novel signature associated with endoplasmic reticulum stress, lipid metabolism, and liver metastasis in pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with high probability of recurrence and distant metastasis. Liver metastasis is the predominant metastatic mode developed in most pancreatic cancer cases, which seriously affects the overall survival rate of patients. Abnormally activated endoplasmic reticulum stress and lipid metabolism reprogramming are closely related to tumor growth and metastasis. This study aims to construct a prognostic model based on endoplasmic reticulum stress and lipid metabolism for pancreatic cancer, and further explore its correlation with tumor immunity and the possibility of immunotherapy. METHODS: Transcriptomic and clinical data are acquired from TCGA, ICGC, and GEO databases. Potential prognostic genes were screened by consistent clustering and WGCNA methods, and the whole cohort was randomly divided into training and testing groups. The prognostic model was constructed by machine learning method in the training cohort and verified in the test, TCGA and ICGC cohorts. The clinical application of this model and its relationship with tumor immunity were analyzed, and the relationship between endoplasmic reticulum stress and intercellular communication was further explored. RESULTS: A total of 92 characteristic genes related to endoplasmic reticulum stress, lipid metabolism and liver metastasis were identified in pancreatic cancer. We established and validated a prognostic model for pancreatic cancer with 7 signatures, including ADH1C, APOE, RAP1GAP, NPC1L1, P4HB, SOD2, and TNFSF10. This model is considered to be an independent prognosticator and is a more accurate predictor of overall survival than age, gender, and stage. TIDE score was increased in high-risk group, while the infiltration levels of CD8+ T cells and M1 macrophages were decreased. The number and intensity of intercellular communication were increased in the high ER stress group. CONCLUSIONS: We constructed and validated a novel prognostic model for pancreatic cancer, which can also be used as an instrumental variable to predict the prognosis and immune microenvironment. In addition, this study revealed the effect of ER stress on cell-cell communication in the tumor microenvironment.

Crosstalk between metabolic remodeling and epigenetic reprogramming: A new perspective on pancreatic cancer.

Pancreatic cancer is a highly malignant solid tumor with a poor prognosis and a high mortality rate. Thus, exploring the mechanisms underlying the development and progression of pancreatic cancer is critical for identifying targets for diagnosis and treatment. Two important hallmarks of cancer-metabolic remodeling and epigenetic reprogramming-are interconnected and closely linked to regulate one another, creating a complex interaction landscape that is implicated in tumorigenesis, invasive metastasis, and immune escape. For example, metabolites can be involved in the regulation of epigenetic enzymes as substrates or cofactors, and alterations in epigenetic modifications can in turn regulate the expression of metabolic enzymes. The crosstalk between metabolic remodeling and epigenetic reprogramming in pancreatic cancer has gained considerable attention. Here, we review the emerging data with a focus on the reciprocal regulation of metabolic remodeling and epigenetic reprogramming. We aim to highlight how these mechanisms could be applied to develop better therapeutic strategies.

Epigenetic regulation in cancer.

Epigenetic modifications are defined as heritable changes in gene activity that do not involve changes in the underlying DNA sequence. The oncogenic process is driven by the accumulation of alterations that impact genome's structure and function. Genetic mutations, which directly disrupt the DNA sequence, are complemented by epigenetic modifications that modulate gene expression, thereby facilitating the acquisition of malignant characteristics. Principals among these epigenetic changes are shifts in DNA methylation and histone mark patterns, which promote tumor development and metastasis. Notably, the reversible nature of epigenetic alterations, as opposed to the permanence of genetic changes, positions the epigenetic machinery as a prime target in the discovery of novel therapeutics. Our review delves into the complexities of epigenetic regulation, exploring its profound effects on tumor initiation, metastatic behavior, metabolic pathways, and the tumor microenvironment. We place a particular emphasis on the dysregulation at each level of epigenetic modulation, including but not limited to, the aberrations in enzymes responsible for DNA methylation and histone modification, subunit loss or fusions in chromatin remodeling complexes, and the disturbances in higher-order chromatin structure. Finally, we also evaluate therapeutic approaches that leverage the growing understanding of chromatin dysregulation, offering new avenues for cancer treatment.

Pancreatic ductal adenocarcinoma chemoresistance: From metabolism reprogramming to novel treatment.

ABSTRACT: As pancreatic cancer (PC) is highly malignant, its patients tend to develop metastasis at an early stage and show a poor response to conventional chemotherapies. First-line chemotherapies for PC, according to current guidelines, include fluoropyrimidine- and gemcitabine-based regimens. Accumulating research on drug resistance has shown that biochemical metabolic aberrations in PC, especially those involving glycolysis and glutamine metabolism, are highly associated with chemoresistance. Additionally, lipid metabolism is a major factor in chemoresistance. However, emerging compounds that target these key metabolic pathways have the potential to overcome chemoresistance. This review summarizes how PC develops chemoresistance through aberrations in biochemical metabolism and discusses novel critical targets and pathways within cancer metabolism for new drug research.

Revealing chronic disease progression patterns using Gaussian process for stage inference.

OBJECTIVE: The early stages of chronic disease typically progress slowly, so symptoms are usually only noticed until the disease is advanced. Slow progression and heterogeneous manifestations make it challenging to model the transition from normal to disease status. As patient conditions are only observed at discrete timestamps with varying intervals, an incomplete understanding of disease progression and heterogeneity affects clinical practice and drug development. MATERIALS AND METHODS: We developed the Gaussian Process for Stage Inference (GPSI) approach to uncover chronic disease progression patterns and assess the dynamic contribution of clinical features. We tested the ability of the GPSI to reliably stratify synthetic and real-world data for osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), bipolar disorder (BP) in the Adolescent Brain Cognitive Development Study (ABCD), and hepatocellular carcinoma (HCC) in the UTHealth and The Cancer Genome Atlas (TCGA). RESULTS: First, GPSI identified two subgroups of OA based on image features, where these subgroups corresponded to different genotypes, indicating the bone-remodeling and overweight-related pathways. Second, GPSI differentiated BP into two distinct developmental patterns and defined the contribution of specific brain region atrophy from early to advanced disease stages, demonstrating the ability of the GPSI to identify diagnostic subgroups. Third, HCC progression patterns were well reproduced in the two independent UTHealth and TCGA datasets. CONCLUSION: Our study demonstrated that an unsupervised approach can disentangle temporal and phenotypic heterogeneity and identify population subgroups with common patterns of disease progression. Based on the differences in these features across stages, physicians can better tailor treatment plans and medications to individual patients.

Epidemiology of pancreatic cancer: New version, new vision.

Pancreatic cancer (PC) is a devastating malignancy with an extremely high mortality rate and poses significant challenges to healthcare systems worldwide. The prevalence of PC risk factors spiked over the years, leading to a global increase in PC incidence rates. The contribution of different risk factors, however, varied from region to region due to genetic predisposition, environmental, social, and political factors underlying disease prevalence in addition to public health strategies. This comprehensive review aims to provide a thorough analysis of the epidemiology of PC, discussing its incidence, risk factors, screening strategies and socioeconomic burden. We compiled a wide range of seminal studies as well as epidemiological investigations to serve this review as a comprehensive guide for researchers, healthcare professionals, and policymakers keen for a more profound understanding of PC epidemiology. This review highlights the essentiality of persistent research efforts, interdisciplinary collaboration, and public health initiatives to address the expanding burden of this malignancy.

ResNet and its application to medical image processing: Research progress and challenges.

BACKGROUND AND OBJECTIVE: Deep learning, a novel approach and subset of machine learning, has drawn a growing amount of attention from computer vision researchers in recent years. This method has drawn a lot of interest because of its extraordinary ability to interpret medical pictures, especially when combined with residual neural networks, which have helped to progress the field. METHODS: In this paper, the following research is carried out on the residual network. First, the research status of ResNet in the medical field is introduced. The fundamental idea behind the residual neural network is then explained, along with the residual unit, its many structures, and the network architecture. Second, four aspects of the widespread use of residual neural networks in medical image processing are discussed: lung tumor, diagnosis of skin diseases, diagnosis of breast diseases, and diagnosis of diseases of the brain. Finally, the main issues and ResNet's future development in the area of processing medical images are discussed. RESULTS: In the area of medical graph processing, residual neural networks have made strides and have had success in the clinical auxiliary diagnosis of serious illnesses such as lung tumors, breast cancer, skin conditions, and cardiovascular and cerebrovascular diseases. CONCLUSION: We thoroughly sorted out the most recent developments in residual neural network research and their use in medical image processing, which serves as a crucial point of reference for this field of study. It offers a helpful reference for further promoting the application and research of the ResNet model in the field of medical image processing by summarising the application status and issues of the ResNet model in the field of medical image processing and putting forwards some future development directions.

Epigenetic reprogramming-induced guanidinoacetic acid synthesis promotes pancreatic cancer metastasis and transcription-activating histone modifications.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) tends to undergo distant metastasis, especially liver metastasis, leading to a poor prognosis. Metabolic remodelling and epigenetic reprogramming are two important hallmarks of malignant tumours and participate in regulating PDAC tumorigenesis and metastasis. However, the interaction between these two processes during PDAC metastasis has not been fully elucidated. METHODS: We performed metabolomics analysis to identify the critical metabolites associated with PDAC liver metastasis and focused on guanidinoacetic acid (GAA). Intracellular GAA content was significantly increased in liver metastatic PDAC cells compared to primary cancer cells in mouse xenograft tumour models. The effects of GAA supplementation and glycine amidinotransferase (GATM) knockdown on PDAC metastasis were assessed by analysing cell migration, filopodia formation, epithelial-mesenchymal transition (EMT), and in vivo metastasis in different cell and animal models. Next, ChIP‒qPCR, 3C‒qPCR, and CRISPRi/dCas9-KRAB experiments were used to validate the "epigenome-metabolome" mechanism. Finally, the results of in vitro approaches, including RNA-seq, CUT&RUN, RT‒qPCR, and western blot analyses, as well as luciferase reporter gene assay and transwell assay, revealed the GAA-c-Myc-HMGA axis and transcription-activating histone modifications reprogramming. RESULTS: A high level of intracellular GAA was associated with PDAC liver metastasis. GAA could promote the migration, EMT, and liver metastasis of pancreatic cancer cells in vitro and in vivo. Next, we explored the role of GATM-mediated de novo GAA synthesis in pancreatic cancer metastasis. High expression of GATM was positively correlated with advanced N stage in PDAC. Knockdown of GATM significantly reduced the intracellular level of GAA, suppressed EMT, and inhibited PDAC liver metastasis, and these effects were attenuated by GAA supplementation. Mechanistically, we identified the active enhancers looped to the Gatm gene locus that promoted GATM expression and PDAC liver metastasis. Furthermore, we found that GAA promoted cell migration and EMT by regulating c-Myc-mediated high mobility group AT-hook protein expression. Moreover, GAA increased the H3K4me3 modification level by upregulating histone methyltransferases, which induced the transcription of metastasis-related genes, including Myc. CONCLUSIONS: These findings revealed the critical role of the epigenome-metabolome interaction in regulating PDAC liver metastasis and suggested potential therapeutic strategies targeting GAA metabolism and epigenetic regulatory mechanisms.

Screening strategy for 1210 exogenous chemicals in serum by two-dimensional liquid chromatography-mass spectrometry.

Humans are at risk of exogenous exposure to exogenous chemicals. Challenges exist for the comprehensive monitoring of residues with different physical and chemical properties in serum. Here, an on-line two-dimensional liquid chromatography (2D-LC) - high resolution mass spectrometry system (HRMS) was developed, expanding the range of the partition coefficient in octanol/water of the residue analysis from -8 to 12. A high-coverage serum residue screening strategy was further designed by integrating 2D-LC system with HRMS full MS/data independent acquisition and automatic spectral library searching. This strategy enables to simultaneously screen 1210 pesticides, veterinary/human drugs, other chemical pollutants and their metabolites in serum with a single analysis. Method validation showed 92% and 81% of 1022 residues spiked in serum could be detected at 50 ng/mL and 5 ng/mL, respectively. The developed method was applied to the analysis of 24 separately pooled serum samples, 58 suspect residues were found, some of them were detected at high frequencies over than 50%. Among them, 4,6-Dinitro-O-cresol and probable carcinogenic folpet are highly toxic, and cimaterol is banned in China. Collectively, this study developed a 2D-LC-HRMS -based screening strategy for screening pesticides, veterinary/human drugs, and other chemical pollutants in serum, it is helpful for studying the effect of exogenous exposures on human health.

mTOR inhibitor, gemcitabine and PD-L1 antibody blockade combination therapy suppresses pancreatic cancer progression via metabolic reprogramming and immune microenvironment remodeling in Trp53flox/+LSL-KrasG12D/+Pdx-1-Cre murine models.

OBJECTIVE: Resistance to immunotherapy and chemotherapy hinders the prognosis of pancreatic cancer(PC). We hypothesized that the combination of mTOR inhibitor sirolimus and gemcitabine would change the metabolic landscape of PC and enhance the anti-PD-L1 therapy. METHODS: In KPC mice, the following regimens were administered and tumor growth inhibition rates(TGI%) were calculated: sirolimus(S), PD-L1 antibody(P), gemcitabine(G), sirolimus + PD-L1 antibody(SP), sirolimus + gemcitabine(SG), PD-L1 + gemcitabine(PG) and sirolimus + PD-L1 antibody + gemcitabine(SPG). The metabolic changes of tumors were identified by LC-MS and subpopulations of immune cells were measured by flow cytometry. Sirolimus treated macrophages were co-cultured with PC cells in vitro, and the metabolic changes of macrophages and tumor cells as well as tumor cells' viability were detected. RESULTS: The monotherapy of S, P and G didn't inhibit tumor growth significantly. The combination of SP, PG and SG didn't improve the TGI% significantly compared with monotherapy. However, the TGI% of SPG combination was higher than other groups. The proportion of CD68+ macrophages increased in the peripheral blood and CD8+ T cells decreased in the tumor tissues after SPG treatment. LC-MS identified 42 differential metabolites caused by sirolimus in SPG group, among which 10 metabolites had potential effects on macrophages. Sirolimus treated M1 and M2 macrophages inhibited the proliferation of tumor cells and decreased tumor cells' glycolysis. The glycolysis of M2 macrophages was increased by sirolimus. CONCLUSIONS: mTOR inhibitor can change the immune microenvironment of PC via metabolic reprogramming, thus promoting the efficacy of PD-L1 blockade when combined with gemcitabine.

Human microbiota colonization and pancreatic ductal carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high mortality rate and a poor prognosis. The human microbiota has been confirmed to participate in oncogenesis and may influence the treatment response to both chemotherapy and immunotherapy. Evidence for the association of the microbiota with PDAC risk, tumorigenesis, treatment response, and survival period is rapidly emerging. The oral microbiota and gut microbiota have the potential to be used in early diagnosis and risk stratification. Intratumor microbiota-targeted intervention strategies may be used as adjuvants to current treatments to improve therapeutic efficacy and overall survival. Here, we summarize the effect and association of the oral, gut and intratumor microbiota on the oncogenesis, progression and treatment of PDAC, as well as the potential of the microbiota to serve as a biomarker for the diagnosis and prognosis of PDAC, as well as a therapeutic target.

Foxa1 mediates eccrine sweat gland development through transcriptional regulation of Na-K-ATPase expression.

Eccrine sweat glands (ESGs) perform critical functions in temperature regulation in humans. Foxa1 plays an important role in ESG maturation and sweat secretion. Its molecular mechanism, however, remains unknown. This study investigated the expression of Foxa1 and Na-K-ATPase (NKA) in rat footpads at different development stages using immunofluorescence staining, qRT-PCR, and immunoblotting. Also, bioinformatics analysis and Foxa1 overexpression and silencing were employed to evaluate Foxa1 regulation of NKA. The results demonstrated that Foxa1 was consistently expressed during the late stages of ESGs and had a significant role in secretory coil maturation during sweat secretion. Furthermore, the mRNA abundance and protein expression of NKA had similar accumulation trends to those of Foxa1, confirming their underlying connections. Bioinformatics analysis revealed that Foxa1 may interact with these two proteins via binding to conserved motifs in their promoter regions. Foxa1 gain-of-function and loss-of-function experiments in Foxa1-modified cells demonstrated that the activities of NKA were dependent on the presence of Foxa1. Collectively, these data provided evidence that Foxa1 may influence ESG development through transcriptional regulation of NKA expression.

Tuning the selectivity of amino acid recognition with dynamic covalent bond constrained fluorophores in aqueous media.

The recognition and discrimination of amino acids are generating continuous interest due to their importance. Herein we developed a series of dynamic covalent reaction constrained aldehyde-derived fluorescent probes for the binding of amino acids with tunable selectivity. Diverse emission behaviors were obtained via pH triggered movement of ring-chain tautomerization equilibrium of aldehyde probes. By taking advantage of the distinct pKa and reactivity of aldehyde probes and amino acids, unique fluorescence signaling patterns were generated, and the selectivity for amino acid recognition was further modulated. The selective recognition of Cys/Hcy was attained at pH 7.4 as a result of thiazolidine formation. The manipulation of the reactivity at pH 10 enabled the realization of high selectivity for His and Cys, respectively. Moreover, pH and redox stimuli-responsive dynamic covalent networks were constructed for the regulation of amino acid recognition. The strategies and results described should be appealing in many aspects, including dynamic assemblies, molecular sensing, biological labeling, and smart materials.

HIF-1α-regulated stanniocalcin-1 mediates gemcitabine resistance in pancreatic ductal adenocarcinoma via PI3K/AKT signaling pathway.

Pancreatic ductal adenocarcinoma (PDAC) has a poor response to the first-line chemotherapy drug gemcitabine. We previously identified stanniocalcin-1 as a gemcitabine-resistant-related gene, but its specific role and function in pancreatic cancer remain unclear. RT-qPCR and Western blot were used to evaluate differential protein and mRNA expressions. The biological functions of genes were determined using proliferation and drug-resistance experiments. Subcutaneous tumorigenesis experiment was performed on nude mice. Prognostic analysis was performed using public databases and our clinical data. We found HIF-1α-regulated STC1 expression mediated chemoresistance in pancreatic cancer. Deeper, we explored the action mechanism of STC1 and identified PI3K/AKT as the downstream signaling pathway of STC1. Furthermore, we analyzed clinical data and found that STC1 expression was related to the prognosis of gemcitabine-treated patients after surgery. In general, we proved the HIF-1α/STC1/PI3K-AKT axis participated in PDAC progression and chemoresistance, and STC1 may serve as a potential prognostic factor and therapeutic target for PDAC treatment.

Association between Temporal Glycemic Change and Risk of Pancreatic Cancer in Men: A Prospective Cohort Study.

Hyperglycemia has been reported to increase the risk of pancreatic cancer (PC), while the association between glycemic change and PC risk has rarely been explored. Using data from a prospective cohort study conducted in China since 2006, 138,870 males with available fasting blood glucose (FBG) levels, including 106,632 males with at least two FBG measurements, were analyzed. The associations between FBG (level, change, and stability) and PC incidence were evaluated using Cox proportional hazard regression and restricted cubic splines. Baseline (p = 0.109) and recent (p = 0.070) FBG levels and incident PC were not significantly associated. U-shaped associations were observed between the annual FBG change and PC risk. Compared with stable FBG, participants with annual FBG change rates <−0.05 mmol/L or >0.15 mmol/L had about four-fold (HR, 4.010; 95% CI: 1.920−8.375) and six-fold (HR, 5.897; 95% CI: 2.935−11.848) higher PC risks, respectively. The PC risk increased by 2.5% (HRlinear = 1.025, 95% CI:1.009−1.042) for every 1% increase in the coefficient of variation for FBG. A subgroup analysis of males without diabetes at baseline showed stronger associations. Temporal FBG changes may be an important factor for identifying populations with high PC risks.

FGFR3 Nuclear Translocation Contributes to Proliferative Potential and Poor Prognosis in Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Fibroblast growth factor receptor 3 (FGFR3) was revealed to have divergent, even opposite roles in different neoplasms. In pancreatic ductal adenocarcinoma (PDAC), its impact on biological behavior and prognosis was not well elucidated. METHODS: Fibroblast growth factor receptor 3 was downregulated by RNA interference to explore its impact on cell proliferative proclivity in PDAC cells. Furthermore, tissue microarray-based immunohistochemistry for FGFR3 was performed in 326 patients with PDAC who underwent radical resection, and its clinicopathologic and prognostic implications were then evaluated. RESULTS: First, successful FGFR3 knockdown remarkably decreased its expression, cell proliferation, and S-phase ratio in the cell cycle in 2 PDAC cell lines, BxPC-3 and AsPC-1. Meanwhile, alterations in p-Akt, cyclin D1, cyclin B1, and p21 were also observed. Subsequently, high nuclear FGFR3 expression, but not cytoplasmic, was significantly common in tumor tissues and positively associated with N stage and dismal overall survival in the entire cohort. In addition, nuclear FGFR3 expression was also prognostic in 10 of 14 subsets. Univariate and multivariate Cox regression analyses identified nuclear expression of FGFR3 as an independent prognosticator in the entire cohort. CONCLUSIONS: Our data showed that FGFR3 nuclear translocation contributes to cell proliferative potential and predicts poor long-term prognosis in PDAC after surgical resection.

Autophagy, not apoptosis, plays a role in lumen formation of eccrine gland organoids.

BACKGROUND: Sweat secreted by eccrine sweat glands is transported to the skin surface through the lumen. The eccrine sweat gland develops from the initial solid bud to the final gland structure with a lumen, but how the lumen is formed and the mechanism of lumen formation have not yet been fully elucidated. This study aimed to investigate the mechanism of lumen formation of eccrine gland organoids (EGOs). METHODS: Human eccrine sweat glands were isolated from the skin for tissue culture, and the primary cultured cells were collected and cultured in Matrigel for 14 days in vitro. EGOs at different development days were collected for hematoxylin and eosin (H&E) staining to observe morphological changes and for immunofluorescence staining of proliferation marker Ki67, cellular motility marker filamentous actin (F-actin), and autophagy marker LC3B. Western blotting was used to detect the expression of Ki67, F-actin, and LC3B. Moreover, apoptosis was detected using a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay kit, and the expression of poly (ADP-ribose) polymerase and Caspase-3 was detected by Western blot. In addition, 3-methyladenine (3MA) was used as an autophagy inhibitor to detect whether the formation of sweat glands can be effectively inhibited. RESULTS: The results showed that a single gland cell proliferated rapidly and formed EGOs on day 4. The earliest lumen formation was observed on day 6. From day 8 to day 14, the rate of lumen formation in EGOs increased significantly. The immunofluorescence and Western blot analyses showed that the expression of Ki67 gradually decreased with the increase in days, while the F-actin expression level did not change. Notably, the expression of autophagy marker LC3B was detected in the interior cells of EGOs as the apoptosis signal of EGOs was negative. Compared with the control group, the autophagy inhibitor 3MA can effectively limit the formation rate of the lumen and reduce the inner diameter of EGOs. CONCLUSION: Using our model of eccrine gland 3D-reconstruction in Matrigel, we determined that autophagy rather than apoptosis plays a role in the lumen formation of EGOs.

Foxa1 mediates eccrine sweat gland development through transcriptional regulation of Na-K-ATPase expression

Eccrine sweat glands (ESGs) perform critical functions in temperature regulation in humans. Foxa1 plays an important role in ESG maturation and sweat secretion. Its molecular mechanism, however, remains unknown. This study investigated the expression of Foxa1 and Na-K-ATPase (NKA) in rat footpads at different development stages using immunofluorescence staining, qRT-PCR, and immunoblotting. Also, bioinformatics analysis and Foxa1 overexpression and silencing were employed to evaluate Foxa1 regulation of NKA. The results demonstrated that Foxa1 was consistently expressed during the late stages of ESGs and had a significant role in secretory coil maturation during sweat secretion. Furthermore, the mRNA abundance and protein expression of NKA had similar accumulation trends to those of Foxa1, confirming their underlying connections. Bioinformatics analysis revealed that Foxa1 may interact with these two proteins via binding to conserved motifs in their promoter regions. Foxa1 gain-of-function and loss-of-function experiments in Foxa1-modified cells demonstrated that the activities of NKA were dependent on the presence of Foxa1. Collectively, these data provided evidence that Foxa1 may influence ESG development through transcriptional regulation of NKA expression.