Pancreatic Cancer Tissues Research Articles

Genome-wide microRNA Analysis Identified miR-210-3p Over-expression in Pancreatic Cancer Tissues as a Predictor of their Local Invasiveness.

The severe malignancy of pancreatic ductal adenocarcinoma (PDAC) is mainly due to frequent local invasiveness and distant metastasis. As for local invasiveness, we previously reported that cancer-specific molecular alterations detected on resected PDAC specimen surfaces, so-called molecular surgical margin (MSM) positiveness, were significantly associated with postoperative locoregional recurrence and distant metastasis. However, due to anatomical limitations, achieving adequate surgical margins during pancreatic cancer resection is often challenging. Therefore, predicting local invasiveness based on the primary tumor's gene profile is crucial to avoid positive MSM. Genome-wide miRNA expression profiles were examined and compared between MSM-positive and negative cases. Candidate miRNAs were evaluated in another validation cohort, and their clinicopathological characteristics were examined. Mimic or inhibitor constructs of the candidate miRNA were transfected to PDAC cell lines to evaluate the miRNA function in the pancreatic cancer cell lines and detect the downstream targets. Among some candidates with highly expressed miRNAs in MSM-positive cases by miRNA expression array, recurrence-free survival (RFS) was significantly shorter in the miR-210-3p high expression group (p=0.015). High miR-210-3p was significantly associated with large tumor diameter (p=0.001), anterior invasion positive (p=0.010), and positive lymph node metastasis (p<0.001). miR-210-3p inhibition in PDAC cell lines resulted in decreased proliferation and invasiveness. The iron-sulfur cluster assembly enzyme (ISCU) gene was identified as a target of miR-210-3p. ISCU reduction was significantly observed in PDAC primary tumors with high levels of miR-210-3p, leading to mitochondrial dysfunction in miR-210-3p-overexpressing PDAC cell lines, as demonstrated by glycolysis stress tests. Highly expressed hypoxia-inducible miR-210-3p in primary PDAC tissues induces locally invasive characteristics through mitochondrial dysfunction by suppressing ISCU expression, which may result in poor postoperative RFS outcomes.

RHOF promotes Snail1 lactylation by enhancing PKM2-mediated glycolysis to induce pancreatic cancer cell endothelial–mesenchymal transition

BackgroundThe influence of the small Rho GTPase Rif (RHOF) on tumor growth, glycolysis, endothelial–mesenchymal transition (EMT), and the potential mechanism of RHOF in pancreatic cancer (PC) were explored.MethodsRHOF expression in PC tissues and cells was assessed by qRT-PCR and western blotting. The viability, proliferation, apoptosis, migration, and invasion of PC cells were assessed using CCK-8, colony formation, EdU, flow cytometry, scratch, and Transwell assays. The expression of EMT- and glycolysis-related proteins was determined using western blotting. The potential mechanisms of action of RHOF in PC were identified using bioinformatic analysis. The effects of RHOF were assessed in vivo using a xenograft mouse model.ResultsPC cell proliferation, migration, and invasion are accelerated by RHOF overexpression, which inhibited apoptosis. RHOF overexpression promoted EMT and glycolysis as evidenced by a decrease in E-cadherin expression and an increase in N-cadherin, Vimentin, HK2, PKM2, and LDHA expression. Bioinformatic analysis indicated that RHOF activated EMT, glycolysis, and Myc targets and that c-Myc could bind to the PKM2 promoter. RHOF overexpression promotes the lactylation and nuclear translocation of Snail1. Silencing Snail1 reversed the promoting effects of RHOF and lactate on cell migration, invasion, and EMT. Moreover, in vivo tumor growth and EMT were inhibited by RHOF silencing.ConclusionRHOF plays an oncogenic role in PC. c-Myc is upregulated by RHOF and promotes PKM2 transcription. PKM2 further induces glycolysis, and the lactate produced by glycolysis causes the lactylation of Snail1, ultimately promoting EMT.

The prognostic significance of twist in pancreatic cancer and its role in cancer promotion through the regulation of the immune microenvironment and EMT mechanisms

ObjectivePancreatic cancer has a poor prognosis due to its high malignancy and rapid progression. The limited immunogenicity of pancreatic cancer (PAAD) contributes to its low responsiveness to immunotherapy, yet its underlying mechanism remains poorly understood. As a cancer promoting gene, Twist participates in EMT in various tumors and promotes tumor progression. The interplay between EMT and the tumor microenvironment (TME) emerges as a pivotal factor influencing tumor immunity and response to immunotherapy. Twist therefore has potential as a biomarker for gauging the outcome of tumour immunotherapy.This research aimed to assess the Twist's prognostic significance in PAAD and its relationship to immunotherapy response.MethodsIn this research, transcriptional data and epigenetic alterations of Twist in pancreatic cancer, along with their impact on the prognosis of PAAD patients, were analyzed using databases. Functional enrichment analysis elucidated the biological role of Twist in PAAD. Subsequently, databases including CIBERSORT and TIDE were employed to investigate the association between Twist expression and immune cell infiltration, immune checkpoint genes, and immunotherapy sensitivity within the pancreatic cancer immune microenvironment.Paraffinized specimens from patients with pancreatic ductal adenocarcinoma confirmed by postoperative pathology were selected for Twist expression verification, and the difference was analyzed by Chi-square test; uncontaminated pancreatic cancer cell lines were used for Twist expression verification, and the differences were analyzed by Student t-test.ResultsTwist mRNA expression was notably upregulated in PAAD, positively correlating with gene methylation levels. Analyses of Kaplan–Meier and Cox regression showed a correlation between better overall survival and lower Twist expression. Functional annotation indicated that Twist-associated differentially expressed genes (DEGs) were involved in EMT regulation and acute inflammation. High expression of Twist leads to a significant reduction in the infiltration of anti-tumor immune cells such as Monocytes, NKcellsactivated, and TcellsCD8, further supporting its creation of a typical immunosuppressive microenvironment in pancreatic cancer. Twist expression is positively correlated with the expression of HARVCR2, LAIR1, LGALS3 and other genes, which may be related to the treatment response to immune checkpoint inhibitors (ICIs). TIDE analysis predicts that patients with high expression of Twist will be insensitive to immunotherapy. Twist is significantly over-expressed in pancreatic cancer cell lines and tissues, and is negatively correlated with E-cadhrin expression, but positively correlated with N-cadherin,Snail, and ZEB1.ConclusionHigh Twist expression in PAAD signifies a grim prognosis. Its elevated levels not only contribute to tumor progression through EMT induction but also exert regulatory control over the immune microenvironment, leading to immunosuppression and diminished effectiveness of immunotherapy.

Identification of Gαi3 as a promising molecular oncotarget of pancreatic cancer.

The increasing mortality rate of pancreatic cancer globally necessitates the urgent identification for novel therapeutic targets. This study investigated the expression, functions, and mechanistic insight of G protein inhibitory subunit 3 (Gαi3) in pancreatic cancer. Bioinformatics analyses reveal that Gαi3 is overexpressed in human pancreatic cancer, correlating with poor prognosis, higher tumor grade, and advanced classification. Elevated Gαi3 levels are also confirmed in human pancreatic cancer tissues and primary/immortalized cancer cells. Gαi3 shRNA or knockout (KO) significantly reduced cell viability, proliferation, cell cycle progression, and mobility in primary/immortalized pancreatic cancer cells. Conversely, Gαi3 overexpression enhanced pancreatic cancer cell growth. RNA-sequencing and bioinformatics analyses of Gαi3-depleted cells indicated Gαi3's role in modulating the Akt-mTOR and PKA-Hippo-YAP pathways. Akt-S6 phosphorylation was decreased in Gαi3-depleted cells, but was increased with Gαi3 overexpression. Additionally, Gαi3 depletion elevated PKA activity and activated the Hippo pathway kinase LATS1/2, leading to YAP/TAZ inactivation, while Gαi3 overexpression exerted the opposite effects. There is an increased binding between Gαi3 promoter and the transcription factor TCF7L2 in pancreatic cancer tissues and cells. Gαi3 expression was significantly decreased following TCF7L2 silencing, but increased with TCF7L2 overexpression. In vivo, intratumoral injection of Gαi3 shRNA-expressing adeno-associated virus significantly inhibited subcutaneous pancreatic cancer xenografts growth in nude mice. A significant growth reduction was also observed in xenografts from Gαi3 knockout pancreatic cancer cells. Akt-mTOR inactivation and increased PKA activity coupled with YAP/TAZ inactivation were also detected in xenograft tumors upon Gαi3 depletion. Furthermore, bioinformatic analysis and multiplex immunohistochemistry (mIHC) staining on pancreatic cancer tissue microarrays showed a reduced proportion of M1-type macrophages and an increase in PD-L1 positive cells in Gαi3-high pancreatic cancer tissues. Collectively, these findings highlight Gαi3's critical role in promoting pancreatic cancer cell growth, potentially through the modulation of the Akt-mTOR and PKA-Hippo-YAP pathways and its influence on the immune landscape.

Integrated bioinformatics analysis identifies PCSK9 as a prognosticator correlated with lipid metabolism in pancreatic adenocarcinoma

BackgroundPancreatic adenocarcinoma (PAAD) is the most frequent kind of pancreatic cancer (PC). Recent studies suggest that lipid metabolism facilitates tumorigenesis, disease progression, and resistance to therapy by promoting lipid synthesis, accumulation, and breakdown. Thus, exploring the lipid metabolism network could unveil novel therapeutic avenues for early detection, precision medicine, and prognostication in PAAD. This project intends to develop new lipid metabolism-related biomarkers for PAAD diagnosis and investigate the link between important genes and immune cell infiltration (ICI).MethodsTissue samples from 20 PAAD patients and 20 healthy controls were obtained. Analysis were focused on the datasets GSE71729 and GSE16515, which include samples of PAAD (n = 161) and those from healthy human tissue (n = 61), derived from the GEO database. Knockdown of PCSK9 on PC cells were conducted by si-RNA and sh-RNA. Migration and cell functional experiments were performed to assess the role of PCSK9 in cell multiplication. Furthermore, a xenograft mouse model was employed to confirm PCSK9's function in vivo.ResultsThe expression level of Proprotein convertase subtilisin/kexin type 9 (PCSK9) is significantly elevated in tissues affected by PAAD when compared to normal tissues. Survival analyses indicated that increased PCSK9 levels are inversely related to overall and disease-free survival (DFS). PCSK9’s functional annotation associated it with the cell cycle and metabolism, especially energy metabolism. Examination of ICI data determined that PCSK9 expression demonstrated an unambiguous association with the M0 macrophages, T follicular helper cells (Tfh), gamma delta T cells and activated DC, and an inverse relationship with Monocytes, CD8+ T cells, memory B cells, resting CD4+ memory T cells, activated NK cells and resting DC abundance. PCSK9 expression knockdown has the ability to impede PC cells’ migration and proliferation.ConclusionOur study identified PCSK9 as a critical gene in PAAD. Expression levels of PCSK9 varied between PAAD and normal samples. ROC analysis verified PCSK9's strong capacity to differentiate PC from normal samples. Importantly, PCSK9 expression was considerably elevated in PC cell lines and tissues. Furthermore, PCSK9 stimulates the migration and proliferation of tumor cells in vivo and vitro.

OSBPL10-CNBP axis mediates hypoxia-induced pancreatic cancer development.

Pancreatic ductal adenocarcinoma (PDAC) is one of malignancies with worst outcomes among digestive system tumors. Identification of novel biomarkers is of great significance for treatment researchesand prognosis prediction of pancreatic cancer patients. Due to OSBPL10 known involvement in oncogenic activity in other tumors, we elucidated the mechanism underlying its contribution to pancreatic cancer progression. We employed data from the Gene Expression Omnibus database to detect the expression of OSBPL10 in normal and pancreatic cancer tissues. A series of assays were conducted to assess the impact of OSBPL10 on the proliferation and metastatic capacities of pancreatic cancer cells and the influence of OSBPL10 on macrophages were evaluated by Flow cytometry. In addition, Co-immunoprecipitation, mass spectrometry, and western blot assays were utilized to investigate the potential mechanisms of OSBPL10 activity. From our study, OSBPL10 is revealed to be upregulated in pancreatic cancer, with poor prognosis. The overexpression promotes malignant behaviors of pancreatic cancer cells and has an impact on tumor immune microenvironment by stimulating the transformation M1 macrophages into M2 macrophages. Mechanistically, hypoxia induces the expression of OSBPL10 through interaction between hypoxia-inducible factor 1-α and the promoter region of OSBPL10. Additionally, OSBPL10 directly bound to CNBP, mediating CNBP expression and ultimately regulating the proliferation and metastasis capacity of pancreatic cancer cells, as well as influencing macrophage polarization. The research emphasized the oncogenic role of OSBPL10 in pancreatic cancer, uncovering key mechanisms involving hypoxia, HIF-1α, and CNBP. The finding suggests that OSBPL10 is a novel biomarker in pancreatic cancer, making it a potential therapeutic target for intervention in this malignancy.

Anti-tissue factor antibody conjugated with monomethyl auristatin E or deruxtecan in pancreatic cancer models.

Antibody-drug conjugates (ADCs) have been recognized as a promising class of cancer therapeutics. Tissue factor (TF), an initiator of the blood coagulation pathway, has been investigated regarding its relationship with cancer, and several preclinical and clinical studies have presented data on anti-TF ADCs, including tisotumab vedotin, which was approved in 2021. However, the feasibility of other payloads in the design of anti-TF ADCs is still unclear because no reports have compared payloads with different cytotoxic mechanisms. For ADCs targeting other antigens, such as Her2, optimizing the payload is also an important issue in order to improve invivo efficacy. In this study, we prepared humanized anti-TF Ab (clone.1084) conjugated with monomethyl auristatin E (MMAE) or deruxtecan (DXd), and evaluated the efficacy in several cell line- and patient-derived xenograft models of pancreatic cancer. As a result, optimizing the drug / Ab ratio was necessary for each payload in order to prevent pharmacokinetic deterioration and maximize delivery efficiency. In addition, MMAE-conjugated anti-TF ADC showed higher antitumor effects in tumors with strong and homogeneous TF expression, while DXd-conjugated anti-TF ADC was more effective in tumors with weak and heterogeneous TF expression. Analysis of a pancreatic cancer tissue array showed weak and heterogeneous TF expression in most TF-positive specimens, indicating that the response rate to pancreatic cancer might be higher for DXd- than MMAE-conjugated anti-TF ADC. Nevertheless, our findings indicated that optimizing the ADC payloads individually in each patient could maximize the potential of ADC therapeutics.

Construction of a novel model based on PVT1-MYC duet-related genes for predicting survival and characterization of the tumor microenvironment in pancreatic cancer.

Pancreatic cancer is an extremely malignant tumor. PVT1 and MYC signaling has been considered as a therapeutic target recently. Nonetheless, the prognostic values and critical regulatory networks of PVT1-MYC duet in pancreatic cancer remain unclear. Firstly, we identified PVT1-MYC duet-related genes using public databases. Then we analyzed our Hi-C and ChIP-seq data to confirm PVT1-MYC duet. We performed LASSO regression and multivariate Cox regression analysis to build a prognostic model whose effectiveness and robustness were validated by Cox regression, ROC analysis, calibration curve, and nomogram. Besides, we conducted functional enrichment analyses, mutation profiles analyses and the immune features analyses to compare low- and high-risk group. Functional enrichment analyses revealed that several terms associated with cancer progression were enriched in the high-risk group. Mutation profile analysis showed that high-risk group had higher tumor mutation burden, and immune analysis demonstrated high-risk group had more immunosuppressive tumor microenvironment. Finally, we detected PVT1 expression in pancreatic cancer and paracancer tissues from the PUMCH cohort, which showed that PVT1 was significantly upregulated in pancreatic cancer and associated with invasion, metastasis, and poor prognosis. We further performed transwell and proliferation assays and found that PVT1, CDC6, and COL17A1 could promote migration or proliferation of PDAC cells. This study constructed a prognostic model based on three PVT1-MYC duet-related genes, which had a significant potential in predicting the prognosis and tumor microenvironment of pancreatic cancer. These results suggested that targeting PVT1-MYC duet or its regulatory processes could be a therapeutic option with great interests.

Resveratrol inhibits pancreatic cancer proliferation and metastasis by depleting senescent tumor-associated fibroblasts.

Pancreatic cancer, a formidable gastrointestinal neoplasm, is characterized by its insidious onset, rapid progression, and resistance to treatment, which often lead to a grim prognosis. While the complex pathogenesis of pancreatic cancer is well recognized, recent attention has focused on the oncogenic roles of senescent tumor-associated fibroblasts. However, their precise role in pancreatic cancer remains unknown. Resveratrol is a natural polyphenol known for its multifaceted biological actions, including antioxidative and neuroprotective properties, as well as its potential to inhibit tumor proliferation and migration. Our current investigation builds on prior research and reveals the remarkable ability of resveratrol to inhibit pancreatic cancer proliferation and metastasis. To explore the potential of resveratrol in inhibiting pancreatic cancer by targeting senescent tumor-associated fibroblasts. Immunofluorescence staining of pancreatic cancer tissues revealed prominent coexpression of α-SMA and p16. HP-1 expression was determined using immunohistochemistry. Cells were treated with the senescence-inducing factors known as 3CKs. Long-term growth assays confirmed that 3CKs significantly decreased the CAF growth rate. Western blotting was conducted to assess the expression levels of p16 and p21. Immunofluorescence was performed to assess LaminB1 expression. Quantitative real-time polymerase chain reaction was used to measure the levels of several senescence-associated secretory phenotype factors, including IL-4, IL-6, IL-8, IL-13, MMP-2, MMP-9, CXCL1, and CXCL12. A scratch assay was used to assess the migratory capacity of the cells, whereas Transwell assays were used to evaluate their invasive potential. Specifically, we identified the presence of senescent tumor-associated fibroblasts within pancreatic cancer tissues, linking their abundance to cancer progression. Intriguingly, Resveratrol effectively eradicated these fibroblasts and hindered their senescence, which consequently impeded pancreatic cancer progression. This groundbreaking discovery reinforces Resveratrol's stature as a potential antitumor agent and positions senescent tumor-associated fibroblasts as pivotal contenders in future therapeutic strategies against pancreatic cancer.

Abstract B023: Unravelling fibroinflammatory and immune signatures for pancreatic cancer early detection

Abstract Pancreatic cancer is associated with late-stage diagnosis and poor patient prognosis. The disease is characterised by chronic dysregulated immunity and inflammation. Moreover, chronic pancreatitis is linked with an increased risk of pancreatic cancer. Tissue remodelling during disease progression involves a complex network of cells and a crosstalk between cancer cells, stromal components and immune cells, but it remains poorly explored. Thus, to improve the outcome of patients, there is a need for better understanding of biological changes associated with the initiation and progression of pancreatic cancer at the molecular and spatial levels. Using samples obtained from our Accelerated Diagnosis of neuroEndocrine and Pancreatic TumourS (ADEPTS) biobank, we have evaluated blood samples for the discovery of non- invasive biomarkers to discriminate patients with pancreatic cancer from symptomatic patients without cancer. In this pilot study, the transcriptome of peripheral blood mononuclear cells (PBMCs), isolated using a ficoll gradient was explored to identify PDAC-associated mRNA signatures. Moreover, the Olink® Explore Inflammation and Oncology panels were performed in a cohort of 40 patients with early stage (I-II) PDAC, 40 chronic pancreatitis samples and 40 control patients with benign symptomatic upper GI diseases. To validate and enrich these results, a panel of inflammatory and immune markers including immunoglobulins, cytokines and chemokines was also run using multiplex techniques. Symptoms observed in our cohort were also analysed together with clinical (e.g diabetic status, biochemistry profile) and demographic data (age, sex, ethnicity, post code etc). We have identified mRNA transcriptome signatures and differentially expressed proteins associated with inflammatory and immunological processes in PDAC compared to benign symptomatic samples. Our results offer potential diagnostic utility for early-stage disease. Additionally, our unique cohort of patient samples comprising of those with confirmed PDAC and those presenting to clinic with benign disease and similar non-specific symptoms, allows for the development of non-invasive diagnostic tests with better translational applicability. Future work will involve the validation of these findings in a larger patient cohort and the use of NanoString GeoMx® Digital Spatial Profiler to perform whole transcriptome and proteome profiling in human chronic pancreatic and pancreatic cancer tissue samples. Citation Format: Kyra Fraser, Maria Rosado, Stephen P Pereira, Pilar Acedo. Unravelling fibroinflammatory and immune signatures for pancreatic cancer early detection [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B023.

Bioinformatical and experimental validation on EFNA5 biomarker for pancreatic cancer

Pancreatic cancer is one of the most aggressive malignancies in the digestive system, characterized by vague early symptoms and rapid disease progression. Currently, treatment options for pancreatic cancer are limited, with unsatisfactory outcomes and poor prognosis, as the overall 5-year survival rate is less than 10%. Therefore, it is crucial to identify new biomarkers for pancreatic cancer.We analyzed the differential expression of EFNA5 at the mRNA level using data from the TCGA, GTEX, and GEO databases, followed by validation of EFNA5 protein expression differences through immunohistochemistry. Kaplan-Meier survival analysis and Cox regression analysis were used to explore the prognostic value of EFNA5. KEGG, GO enrichment analyses, and GSEA were employed to predict the biological functions of EFNA5. Bioinformatics algorithms were utilized to analyze the impact of EFNA5 on drug sensitivity, immune cell infiltration, and tumor mutational burden. Finally, we conducted cell phenotype experiments to investigate the effects of EFNA5 on the proliferation, migration, and invasion of pancreatic cancer cells. Bioinformatics data showed that the mRNA level of EFNA5 was higher in pancreatic cancer tissues compared to normal tissues. Immunohistochemistry experiments confirmed that the protein expression level of EFNA5 was significantly higher in pancreatic cancer tissues (n = 19) than in adjacent normal tissues (n = 19). Survival analysis indicated that the overall survival (OS) and progression-free survival (PFS) were worse in the high EFNA5 expression group compared to the low expression group. Univariate and multivariate Cox regression analyses demonstrated that EFNA5 is a risk factor affecting the prognosis of pancreatic cancer patients. KEGG pathway enrichment analysis revealed that differentially expressed genes (DEGs) between high and low EFNA5 expression groups were primarily enriched in pathways such as PI3K/Akt, axon guidance, and focal adhesion. GO enrichment analysis showed that DEGs were mainly associated with functions like epidermis development, cell adhesion, and intercellular junctions. Immune cell infiltration analysis found that EFNA5 expression was correlated with the infiltration levels of various immune cells. The tumor mutational burden was higher in the high EFNA5 expression group compared to the low expression group. Drug sensitivity analysis indicated that the high EFNA5 expression group had lower sensitivity to several commonly used chemotherapy drugs for pancreatic cancer. Cellular experiments demonstrated that knocking down EFNA5 inhibited the proliferation, invasion, and migration of pancreatic cancer cells. EFNA5 is overexpressed in pancreatic cancer tissues, and its high expression is associated with poor prognosis in pancreatic cancer patients. Downregulation of EFNA5 reduces the proliferation, migration, and invasion capabilities of the pancreatic cancer cell line BxPC-3. EFNA5 is closely related to the occurrence, development, prognosis, immune infiltration, and drug sensitivity of pancreatic cancer. Our study suggests that EFNA5 is a potential biomarker and therapeutic target.

MISP-mediated enhancement of pancreatic cancer growth through the Wnt/β-catenin signaling pathway is suppressed by Fisetin

Pancreatic cancer is a highly malignant tumor characterized by high mortality and low survival rates. The mitotic interactor and substrate of Plk1 (MISP) is a cancer-associated protein that regulates mitotic spindle localization and is highly expressed in several malignant tumors, contributing to tumor development. However, the function and regulatory mechanisms of MISP in pancreatic cancer remain unclear. In this study, we analyzed RNA sequencing data related to pancreatic cancer from the TCGA and GEO databases, identifying MISP as a potential prognostic marker for the disease. MISP was significantly upregulated in pancreatic cancer cells and tissues compared to normal pancreatic cells and tissues. Notably, in pancreatic cancer cells, high MISP protein expression promoted cell proliferation and growth. Mechanistically, the upregulation of MISP facilitated the nuclear accumulation of β-catenin, thereby activating the Wnt/β-catenin signaling pathway and promoting pancreatic cancer growth. In search of effective inhibitors of MISP expression, we screened an FDA-approved drug library and identified Fisetin as a potential suppressor of MISP expression. Fisetin was found to downregulate the transcription factor MYB, thereby reducing MISP expression. Further experiments demonstrated that Fisetin effectively inhibited the in vitro and in vivo growth of pancreatic cancer by suppressing the MISP/Wnt/β-catenin signaling axis. In summary, our research has identified MISP as a novel therapeutic target in pancreatic cancer and uncovered its associated regulatory mechanisms.

Identification of STAM-binding protein as a target for the treatment of gemcitabine resistance pancreatic cancer in a nutrient-poor microenvironment

Pancreatic cancer (PC) is a highly malignant solid tumor whose resistance to gemcitabine (GEM) chemotherapy is a major cause of poor patient prognosis. Although PC is known to thrive on malnutrition, the mechanism underlying its chemotherapy resistance remains unclear. The current study analyzed clinical tissue sample databases using bioinformatics tools and observed significantly upregulated expression of the deubiquitinase STAMBP in PC tissues. Functional experiments revealed that STAMBP knockdown remarkably increases GEM sensitivity in PC cells. Multiple omics analyses suggested that STAMBP enhances aerobic glycolysis and suppresses mitochondrial respiration to increase GEM resistance in PC both in vitro and in vivo. STAMBP knockdown decreased PDK1 levels, an essential regulator of the aerobic glycolytic process, in several cancers. Mechanistically, STAMBP promoted the PDK1-mediated Warburg effect and chemotherapy resistance by modulating E2F1 via direct binding to E2F1 and suppressing its degradation and ubiquitination. High-throughput compound library screening using three-dimensional protein structure analysis and drug screening identified the FDA drug entrectinib as a potent GEM sensitizer and STAMBP inhibitor, augmenting the antitumor effect of GEM in a patient-derived xenograft (PDX) model. Overall, we established a novel mechanism, via the STAMBP–E2F1–PDK1 axis, by which PC cells become chemoresistant in a nutrient-poor tumor microenvironment.

Knockdown of LncRNA-HAGLR restrains the viability and motility of pancreatic cancer via miR-625-5p/TAF15 axis in vitro and invivo

Dysregulation of long non-coding RNAs (lncRNAs) has been strongly involved to the development of pancreatic cancer (PC). However, the potential mechanisms by which lncRNA regulate PC development still need to be further explored. We attempted to elucidate the functional role and regulatory mechanism of lncRNA HAGLR on PC progression in vitro and vivo. RT-qPCR, Western blot, RNA pull-down, luciferase reporter assay, RNA immunoprecipitation assay, CCK-8 assay, EdU assay, flow cytometry, transwell assay and xenograft tumor experiment were performed in this study. We found that the expressions of HAGLR and TAF15 were increased in PC tissues and cells. HAGLR silencing restrained the PC cell growth and invasion, but induced cell apoptosis. Moreover, HAGLR targeted miR-625-5p to modulate the expression of TAF15. HAGLR overexpression partially eliminated the suppressive effect of TAF15 depletion on PC cell growth and the stimulative effect on apoptosis. In vivo assays showed that HAGLR knockdown inhibited PC cell growth by regulating the TAF15 expression. These findings suggest HAGLR could facilitate PC cell malignant behaviors through regulating the TAF15 expression, demonstrating that HAGLR might be a valuable target for the PC treatment.

Long non-coding RNA MIR4435-2HG promotes pancreatic cancer progression by regulating ABHD17C through sponging miR-128-3p.

The recently identified carcinogenic long non-coding RNA (lncRNA) MIR4435-2HG has been validated to contribute to the initiation and progression of several malignancies. Nonetheless, its specific mechanistic function in pancreatic cancer (PC) is yet to be determined. This study aims to investigate the expression and functional role of MIR4435-2HG in PC and to elucidate its potential mechanism. This study employed The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx)-Pancreas datasets for the analysis of MIR4435-2HG expression in PC and normal pancreatic tissues and its relations with prognosis in PC. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was employed for analyzing MIR4435-2HG, miR-128-3p, and ABHD17C expressions within cells and tissues. Cell proliferation and apoptosis were detected in vitro through Cell Counting Kit 8 (CCK-8) assay and flow cytometry while utilizing transwell and wound healing assays to assess cell migration and invasion. Predicting miR-128-3p binding sites with MIR4435-2HG or ABHD17C was conducted via the online tool starBase and validated through a dual-luciferase reporter (DLR), RNA pull-down and RNA binding protein immunoprecipitation (RIP) assays. Herein, we deployed Western blot to assess protein expression levels. The in vivo role of MIR4435-2HG was studied using tumor xenografts. MIR4435-2HG overexpression exhibited a correlation with poor prognosis in PC. Knocking down MIR4435-2HG significantly hindered the proliferative, invading, and migrating PC cell abilities, accompanied by apoptosis induction, counteracted via a miR-128-3p inhibitor. Moreover, MIR4435-2HG could directly bind to miR-128-3p. Additionally, miR-128-3p directly targeted ABHD17C. Furthermore, in vitro as well as in vivo experiment results elucidated that knocking down MIR4435-2HG hindered PC progression by suppressing ABHD17C expression via miR-128-3p upregulation. MIR4435-2HG can serve as a dependable target for PC diagnosis and treatment by modulating the miR-128-3p/ABHD17C axis to promote its progression.

Implication of Capillary Morphogenesis Gene 2 (CMG2) in the Disease Progression and Peritoneal Metastasis of Pancreatic Cancer.

Capillary morphogenesis gene 2 (CMG2) mediates cell-matrix interactions to facilitate cell adhesion and migration. CMG2 has been implicated in the disease progression of breast cancer, prostate cancer and gastric cancer. The present study aims to determine the role of CMG2 in the disease progression and peritoneal metastasis of pancreatic cancer. Pancreatic tumour samples were collected from Peking University Cancer Hospital. CMG2 expression was determined using quantitative PCR. After the creation of knockdown and overexpression of CMG2 in pancreatic cancer cells, the effect of CMG2 on several cell functions and adhesion to the peritoneum was examined. Potential pathways regulated by CMG2 were found via proteomics analysis and drug tests. CMG2 was upregulated in pancreatic cancer tissues and associated with a poor prognosis. CMG2 was increased in metastatic lesions and those primary tumours with distant metastases. CMG2 promotes cell-cell, cell-matrix and cell-hyaluronic acid adhesion, which may be mediated by epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK) pathway activation.

Selective and effective suppression of pancreatic cancer through MNK inhibition

Objective The study aimed to explore the role of the Wnt/β-catenin signaling pathway in pancreatic cancer progression and chemoresistance, with a focus on identifying specific factors that distinguish between normal and tumor cells, thereby offering potential therapeutic targets. Materials and Methods We analyzed levels of total and phosphorylated eukaryotic translation initiation factor 4E (eIF4E) and β-catenin in pancreatic cancer and normal pancreatic tissues. Functional assays were used to assess the impact of eIF4E phosphorylation on β-catenin signaling, cell proliferation, and chemoresistance, with MNK kinase involvement determined through gene depletion studies. The MNK kinase inhibitor eFT508 was evaluated for its effects on eIF4E phosphorylation, β-catenin activation, and cell viability in both in vitro and in vivo models of pancreatic cancer. Results Both total and phosphorylated eIF4E, along with β-catenin, were significantly elevated in pancreatic cancer tissues compared to normal tissues. Phosphorylation of eIF4E at serine 209 was shown to activate β-catenin signaling, enhance cell proliferation, and contribute to chemoresistance in pancreatic cancer. Importantly, these effects were dependent on MNK kinase activity. Depletion of eIF4E reduced cell viability in both pancreatic cancer and normal cells, while depletion of MNK selectively decreased viability in pancreatic cancer cells. Treatment with eFT508 effectively inhibited eIF4E phosphorylation, suppressed β-catenin activation, and reduced pancreatic cancer cell growth and survival in vitro and in vivo, with minimal impact on normal cells. Conclusions: The MNK-eIF4E-β-catenin axis plays a critical role in pancreatic cancer progression and chemoresistance, distinguishing pancreatic cancer cells from normal cells. Targeting MNK kinases with inhibitors like eFT508 presents a promising therapeutic strategy for pancreatic cancer, with potential for selective efficacy and reduced toxicity.

Targeting AGTPBP1 inhibits pancreatic cancer progression via regulating microtubules and ERK signaling pathway

BackgroundAGTPBP1 is a cytosolic carboxypeptidase that cleaves poly-glutamic acids from the C terminus or side chains of α/β tubulins. Although its dysregulated expression has been linked to the development of non-small cell lung cancer, the specific roles and mechanisms of AGTPBP1 in pancreatic cancer (PC) have yet to be fully understood. In this study, we examined the role of AGTPBP1 on PC in vitro and in vivo.MethodsImmunohistochemistry was used to examine the expression of AGTPBP1 in PC and non-cancerous tissues. Additionally, we assessed the malignant behaviors of PC cells following siRNA-mediated AGTPBP1 knockdown both in vitro and in vivo. RNA sequencing and bioinformatics analysis were performed to identify the differentially expressed genes regulated by AGTPBP1.ResultsWe determined that AGTPBP1 was overexpressed in PC tissues and the higher expression of AGTPBP1 was closely related to the location of tumors. AGTPBP1 inhibition can significantly decrease cell progression in vivo and in vitro. Moreover, the knockdown of AGTPBP1 inhibited the expression of ERK1/2, P-ERK1/2, MYLK, and TUBB4B proteins via the ERK signaling pathway.ConclusionOur research indicates that AGTPBP1 may be a putative therapeutic target for PC.

Curcumin Inhibits the Development of Pancreatic Cancer by Targeting the circ_0079440/miR-522-3p/EIF4A1 Pathway.

Pancreatic cancer (PC) is a common gastrointestinal cancer with high invasiveness and high mortality. Curcumin is a natural polyphenol with anti-tumor activity against different cancers, including PC. Curcumin has been verified to mediate the expression of circular RNAs (circRNAs) to inhibit tumor development. This study aimed to explore the function and regulatory mechanism of curcumin on circ_0079440 in PC. PC cells were treated with different concentrations of curcumin (0, 5, 10 or 15 μM) for 24 h. Gene expression in PC cells and tissues was detected using RT-qPCR. Cell malignant phenotypes were determined by functional assays. The levels of EMT-related proteins were tested using western blot. RNA interaction was determined using RNA pulldown assay, luciferase reporter assay and RIP assay. The results showed that curcumin suppressed cell proliferative, migratory, and invasive capabilities, and weakened epithelial-mesenchymal transition (EMT) in a concentration-dependent way. Circ_0079440 was expressed at a high level in PC and its level was reduced via curcumin administration in PC cells. Rescue assays showed that circ_0079440 overexpression reversed the suppressive effects of curcumin on PC cell malignant phenotypes. Furthermore, in the xenograft mouse models, curcumin treatment inhibited tumor growth and metastasis, and circ_0079440 upregulation reversed the function of curcumin. Additionally, circ_0079440 was revealed to bind to miR-522-3p to upregulate eukaryotic initiation factor 4A1 (EIF4A1) expression in PC cells. EIF4A1 expression was also downregulated by curcumin, and EIF4A1 overexpression abolished the suppressive functions of curcumin. Moreover, EIF4A overexpression or miR-522-3p inhibition counteracted the anti-tumor effects of circ_0079440 depletion on PC development. To sum up, curcumin suppresses PC development by targeting the circ_0079440/miR-522-3p/EIF4A1 pathway, which might provide novel therapeutic targets for treatment of PC.

HTF4 modulates the transcription of GID2 to promote the malignant biological behavior of pancreatic cancer

BackgroundHelix-loop-helix transcription factor 4 (HTF4) as an anti-cancer target has been reported in many human cancers, but limited data exists regarding the effect of HTF4 in pancreatic cancer. In this study, we aimed to investigate the role of HTF4 in pancreatic cancer. MethodsThe expression levels of HTF4 in clinical pancreatic cancer samples were measured. HTF4 was knocked down or overexpressed in pancreatic cancer cells and was subsequently tested for bio-function using in vitro assays and in vivo. The regulation of HTF4 on GID2 was assessed via bioinformatic tools and dual-luciferase reporter assay. ResultsWe found that HTF4 was highly expressed in pancreatic cancer tissues and correlated with poor patient prognosis. In addition, knocking down HTF4 expression inhibited cell proliferation, migration, and invasion, whereas HTF4 overexpression exerted the opposite effect. Moreover, HTF4 promoted tumor growth and metastasis in pancreatic cancer. Further, HTF4 bound to the GID2 promoter region and promoted transcriptional activation of GID2 in pancreatic cancer cells. GID2 knockdown suppressed HTF4-induced malignant behaviors of pancreatic cancer cells. ConclusionsOur findings suggest that the HTF4/GID2 axis accelerates the progression of pancreatic cancer, providing a potential therapeutic target and prognostic indicator for the treatment of pancreatic cancer patients.