Prognosis In PDAC Research Articles

The tumor immune microenvironment in resected treatment-naive pancreatic cancer patients with long-term survival

BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide. Presently, only a fraction of patients undergo successful surgical resection, the most effective treatment. Enhancing treatment strategies necessitates a deep comprehension of the factors underlying extended survival after surgical resection in patients. MethodsThis study aims to identify the important factors of PDAC patients’ long-term survival with metatranscriptomics and multiplex immunofluorescence (IF) staining analyses. Specifically, differences in tumor immune microenvironment (TIME) were investigated between treatment-naïve PDAC short-term survivors (STS, overall survival <6 months) and long-term survivors (LTS, overall survival >5 years). ResultsAs a result, we detected 589 over-expressed genes, including HOXB9, CDA, and HOXB8, and 507 under-expressed genes, including AMY2B, SCARA5, and SLC2A2 in LTS. Most of the Reactome overbiological pathways enriched in our data were over-expressed in LTS, such as RHO GTPase Effectors and Cell Cycle Checkpoints. Eleven microbiomes significantly differed between LTS and STS, including Sphingopyxis and Capnocytophaga. Importantly, we demonstrate that the TIME profile with an increased abundance of memory B cells and the reduction of M0 and pro-tumoral M2 macrophages are associated with a good prognosis in PDAC. ConclusionsIn this study, we delved into the TIME with metatranscriptomics and IF staining analyses to understand the prerequisite of prolonged survival in PDAC patients. In LTS, several biological pathways were overexpressed, and specific microbiomes were identified. Furthermore, apparent differences in driven immune factors were found that provide valuable insights into developing new treatment strategies.

Tumour-associated myeloid cells expressing IL-10R2/IL-22R1 as a potential biomarker for diagnosis and recurrence of pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor survival rate, largely due to the lack of early diagnosis. Although myeloid cells are crucial in the tumour microenvironment, whether their specific subset can be a biomarker of PDAC progression is unclear.MethodsWe analysed IL-22 receptor expression in PDAC and peripheral blood. Additionally, we analysed gene expression profiles of IL-10R2+/IL-22R1+ myeloid cells and the presence of these cells using single-cell RNA sequencing and murine orthotropic PDAC models, respectively, followed by examining the immunosuppressive function of IL-10R2+/IL-22R1+ myeloid cells. Finally, the correlation between IL-10R2 expression and PDAC progression was evaluated.ResultsIL-10R2+/IL-22R1+ myeloid cells were present in PDAC and peripheral blood. Blood IL-10R2+ myeloid cells displayed a gene expression signature associated with tumour-educated circulating monocytes. IL-10R2+/IL-22R1+ myeloid cells from human myeloid cell culture inhibited T cell proliferation. By mouse models for PDAC, we found a positive correlation between pancreatic tumour growth and increased blood IL-10R2+/IL-22R1+ myeloid cells. IL-10R2+/IL-22R1+ myeloid cells from an early phase of the PDAC model suppressed T cell proliferation and cytotoxicity. IL-10R2+ myeloid cells indicated tumour recurrence 130 days sooner than CA19-9 in post-pancreatectomy patients.ConclusionsIL-10R2+/IL-22R1+ myeloid cells in the peripheral blood might be an early marker of PDAC prognosis.

Abstract CT136: Phase Ib study of siltuximab and spartalizumab in advanced pancreatic cancer

Abstract Background: Pancreatic adenocarcinoma (PDAC) is an aggressive malignancy with dismal prognosis. Most patients present with advanced stages. Heightened levels of serum interleukin-6 (IL-6) are associated with carcinogenesis, immune suppression, and poor prognosis in PDAC. Preclinical data of dual inhibition of IL-6 and programmed death ligand-1 (PD-L1) facilitates CD8+ T-cell migration into pancreatic tumors and was effective in controlling tumor growth in syngeneic and genetically engineered PDAC mouse models. Siltuximab (Sil) is a chimeric monoclonal antibody which targets the IL-6 molecule specifically. Spartalizumab (Sparta) is a high-affinity ligand-blocking humanized IgG4 antibody against the PD-1 receptor. We developed a phase Ib/II trial to evaluate the safety, immunogenicity and preliminary antitumor activity of Sil and Sparta in metastatic PDAC (mPDAC). Methods: Patients (pts) with mPDAC who have progressed on at least one line of systemic chemotherapy were eligible for the trial. Other selected inclusion criteria were ≥18 years of age, ECOG PS 0-1 and measurable disease per RECIST v1.1. The phase Ib trial design is standard 3+3, with a primary endpoint of recommended phase II dose (RP2D). An additional 24 patients were planned for an expansion cohort. Sil was administered at escalating dose levels of 6 mg/kg (DL1) and 11 mg/kg (DL2), in combination with Sparta at 300 mg IV on day 1 of each 21-day cycle. Key secondary endpoints included overall response rate (ORR = CR + PR), progression-free survival (PFS) and overall survival (OS). Results: We enrolled 4 patients on DL1 and escalated to DL2/RP2D in the absence of a dose limiting toxicity (DLT). A total of 31 patients were subsequently treated at the RP2D (escalation + expansion). The median age was 68 years, 42% were male. Majority were White (63%) and 20% were Black. About 43% had head of pancreas primary tumors and 86% had liver involvement. The median number of lines of prior therapy was 3 (range 1-4). There was no objective response among the 4 patients on DL1; 1 had stable disease (SD) for 11 weeks as best response. 17 of 31 patients on RP2D had only a baseline assessment and came off study for progression of disease, prior to follow-up imaging assessment for response evaluation. Of the 14 RP2D patients with a follow-up assessment, ORR was 0% (3 were SD and 11 had progression of disease (PD) as best response), mPFS - 2.2 mos (95% CI: 1.9, 2.6), mOS - 5.5mos (95% CI: 2.8, 6.5). Treatment related adverse events (TRAEs) of any grade included fatigue (23%), anemia (18%), and increased liver enzymes (9.5%). There were no grade 4-5 TRAEs. Conclusions: The combination Sil/Sparta had an acceptable safety profile but did not elicit responses in advanced PDAC pts. Correlative studies using paired biopsies and blood are ongoing to determine how dual IL-6/PD-1 blockade impacts stromal and immune biomarkers in relationship to the clinical outcome measures. Funding and medications for the study were provided by Novartis and Recordati Rare Diseases Inc (NCT04191421) and NIH/NCI (R21CA266088). Citation Format: Olatunji B. Alese, Olumide Gbolahan, Kathleen M. Coleman, Yichun Cao, Sujata Kane, Sarah Craven, Emily Greene, Natalie Horvat, Andrew McDonald, Walid L. Shaib, Christina S. Wu, Mehmet Akce, Maria Diab, Jeffrey M. Switchenko, Gregory B. Lesinski, Bassel F. El-Rayes. Phase Ib study of siltuximab and spartalizumab in advanced pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT136.

Abstract 4435: Taurine metabolism as a marker for pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC), known for its aggressive nature and poor prognosis, presents a significantly altered metabolic landscape compared to normal pancreatic tissue, a feature that has been the focus of recent research but remains underexplored in actual pancreatic tissues. In this study, we undertook an untargeted metabolomics analysis to compare the metabolic profiles of PDAC with matched normal tissues, revealing a notable elevation in taurine levels in PDAC. This increase was further validated through immunohistochemistry in separate PDAC and normal tissue samples. To delve deeper, we conducted a comprehensive bioinformatics analysis, integrating transcriptomic and proteomic data, which identified the taurine metabolism pathway as significantly altered, with ADO emerging as a pivotal gene in this process. Further investigations, including gene modulation and xenograft models, demonstrated that ADO knockdown curtails cancer cell proliferation and tumor growth, potentially impacting the Raf-MEK-ERK signaling pathway. Clinically, the ADO-Taurine axis was found to have substantial prognostic significance, correlating with recurrence rates and survival in PDAC patients. These insights collectively suggest that the ADO-Taurine axis, through its modulation of taurine metabolism, presents as a promising biomarker for PDAC prognosis and a potential avenue for therapeutic development. Citation Format: Hoonsik Nam, Woohyung Lee, Ha T. Nguyen, Linh X. Mai, Song Cheol Kim, Sunghyouk Park. Taurine metabolism as a marker for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4435.

TRIM29 facilitates gemcitabine resistance via MEK/ERK pathway and is modulated by circRPS29/miR-770–5p axis in PDAC

AimsPancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease. Chemotherapy based on gemcitabine (GEM) remains the first-line drug for patients with advanced PDAC. However, GEM resistance impairs its therapeutic effectiveness. Therefore, identifying effective therapeutic targets are urgently needed to overcome GEM resistance. MethodsThe clinical significance of Tripartite Motif Containing 29 (TRIM29) was identified by exploring GEO datasets and TCGA database and its potential biological functions were predicted by GSEA analysis. The regulatory axis was established by bioinformatics analysis and validated by mechanical experiments. Then, in vitro and in vivo assays were performed to validate the roles of TRIM29 in PDAC GEM resistance. ResultsHigh TRIM29 expression was associated with poor prognosis of PDAC and functional experiments demonstrated that TRIM29 promoted GEM resistance in PDAC GEM-resistant (GR) cells. Furthermore, we revealed that circRPS29 promoted TRIM29 expression via competitive interaction with miR-770–5p and then activated MEK/ERK signaling pathway. Additionally, both in vitro and in vivo functional experiments demonstrated that circRPS29/miR-770–5p/TRIM29 axis promoted PDAC GEM resistance via activating MEK/ERK signaling pathway. ConclusionOur results identify the significance of the signaling axis, circRPS29/miR-770–5p/TRIM29-MEK/ERK, in PDAC GEM resistance, which will provide novel therapeutic targets for PDAC treatment.

Identification of a novel m6A-related lncRNAs signature and immunotherapeutic drug sensitivity in pancreatic adenocarcinoma

BackgroundPancreatic adenocarcinoma (PDAC) ranks as the fourth leading cause for cancer-related deaths worldwide. N6-methyladenosine (m6A) and long non-coding RNAs (lncRNAs) are closely related with poor prognosis and immunotherapeutic effect in PDAC. The aim of this study is to construct and validate a m6A-related lncRNAs signature and assess immunotherapeutic drug sensitivity in PDAC.MethodsRNA-seq data for 178 cases of PDAC patients and 167 cases of normal pancreatic tissue were obtained from TCGA and GTEx databases, respectively. A set of 21 m6A-related genes were downloaded based on the previous report. Co-expression network was conducted to identify m6A-related lncRNAs in PDAC. Cox analyses and least absolute shrinkage and selection operator (Lasso) regression model were used to construct a risk prognosis model. The relationship between signature genes and immune function was explored by single-sample GSEA (ssGSEA). The tumor immune dysfunction and exclusion (TIDE) score and tumor mutation burden (TMB) were utilized to evaluate the response to immunotherapy. Furthermore, the expression levels of 4 m6A-related lncRNAs on PDAC cell lines were measured by the quantitative real-time PCR (qPCR). The drug sensitivity between the high- and low-risk groups was validated using PDAC cell lines by Cell-Counting Kit 8 (CCK8).ResultsThe risk prognosis model was successfully constructed based on 4 m6A-related lncRNAs, and PDAC patients were divided into the high- and low-risk groups. The overall survival (OS) of the high-risk groups was more unfavorable compared with the low-risk groups. Receiver operating characteristic (ROC) curves demonstrated that the risk prognosis model reasonably predicted the 2-, 3- and 5-year OS of PDAC patients. qPCR analysis confirmed the decreased expression levels of 4 m6A-related lncRNAs in PDAC cells compared to the normal pancreatic cells. Furthermore, CCK8 assay revealed that Phenformin exhibited higher sensitivity in the high-risk groups, while Pyrimethamine exhibited higher sensitivity in the low-risk groups.ConclusionThe prognosis of patients with PDAC were well predicted in the risk prognosis model based on m6A-related lncRNAs, and selected immunotherapy drugs have potential values for the treatment of pancreatic cancer.

Association between TP53 gain of function and loss of function mutational subgroups and survival in pancreatic adenocarcinoma.

694 Background: TP53 is a commonly mutated tumor suppressor in pancreatic adenocarcinoma (PDAC) but the clinical implications for different classes of TP53 variants remain unclear. In contrast to loss of function (LOF) mutations, TP53 gain of function (GOF) mutations alter DNA conformational binding (e.g. R175H, G245S, R249S, R282H) or modify DNA contact hotspots (e.g. R248Q, R248W, R273H) and are associated with aggressive phenotypes. Here, we analyze progression-free survival (PFS) on standard therapies and overall survival (OS) of PDAC patients (pts) within TP53 mutational subgroups: GOF, LOF, and wild type (WT). Methods: We analyzed longitudinal outcomes across 775 pts with next generation DNA sequencing (NGS) results from Perthera’s Real-World Evidence database who received at least 1 line of therapy in the advanced setting for PDAC. PFS was evaluated from initiation of 1st line for advanced disease until discontinuation. Hazard ratios and p-values were computed via Cox regression when comparing OS relative to date of advanced diagnosis and PFS on subsets who received 1st line FOLFIRINOX (FFX) or 1st line gemcitabine/nab-paclitaxel (GA). Differences in frequencies of genomic alterations between TP53 mutational subgroups were analyzed by Fisher’s exact test. Results: In the TP53 LOF subgroup, median PFS on 1st line GA was significantly worse than 1st line FFX (Table) but this difference was not observed in TP53 GOF or WT subgroups. Irrespective of 1st line therapy choice, median OS in the WT subgroup (2.1y [1.8-2.4]) was significantly longer (p&lt;0.05) than pts with TP53 GOF (1.5y [1.3-2.1]) or TP53 LOF (1.4y [1.3-1.5]). KRAS mutations were enriched (unadjusted p&lt;0.05) for co-occurrence with TP53 in GOF (93.7%) and LOF (93.3%) subgroups relative to WT (74.5%). Mutations in BRCA1/2 were less common in the TP53 GOF subgroup (2.5%) relative to LOF (5.1%) and WT (11.6%). ATM mutations as well as an expanded set of genomic alterations within the DDR pathway were also enriched with similar trends (GOF&lt;LOF&lt;WT). Other potentially confounding factors will be discussed in the context of multivariate OS/PFS analyses. Conclusions: TP53 mutations correlated with worse prognosis in advanced PDAC. Potential predictive associations favoring FFX over GA in the TP53 LOF subgroup (but not in GOF or WT subgroups) warrant further exploration. [Table: see text]

Abstract C002: Interleukin-1 receptor accessory protein (IL1RAP) overexpression is associated with worse prognosis in PDAC and is targetable by nadunolimab

Abstract Introduction: The pancreatic tumor microenvironment (TME) is a major driver of tumor progression, chemoresistance and immune suppression, and the IL-1 axis has been implicated in tumor-promoting signaling networks. The IL1RAP-IL1R1 receptor complex is required for both IL-1α and IL-1β signaling and is expressed on tumor and stromal/immune cells. Nadunolimab is a fully humanized, ADCC-enhanced IgG1 antibody that targets IL1RAP and disrupts both IL-1α/IL-1β signaling. In the phase 1/2a trial CANFOUR (NCT03267316) in which 73 PDAC patients with previously untreated, locally advanced or metastatic PDAC received nadunolimab with gemcitabine/nab-paclitaxel (GN), encouraging preliminary data show median iPFS of 7.2 mo, median OS of 12.9 mo and 1-year survival of 58%. The present analyses investigated the correlation between IL1RAP expression and disease severity as well as therapeutic efficacy of nadunolimab/GN. Methods: Evaluable screening biopsies from 46 CANFOUR PDAC patients were stained for IL1RAP by immunohistochemistry. mRNA data was obtained from the GTEx, TCGA and Pancreatic Cancer Action Network’s Know Your Tumor (KYT) databases and correlated to patient data (TCGA, KYT) and mutational data (KYT). Results: IL1RAP expression was detected on tumor cells, fibroblasts, and infiltrating immune cells in tumor biopsies. Notably, all tumor cells expressed IL1RAP and stratification of evaluable samples into high or low tumor cell expression of IL1RAP revealed significantly prolonged median OS on nadunolimab/GN in IL1RAP high compared to IL1RAP low patients (14.2 vs 10.6 mo, p=0.017). This was also reflected in longer iPFS (8.0 vs 5.8 mo), 1-year survival (69 vs 40%) and iORR (52 vs 32%). Although varying in intensity, IL1RAP expression on stromal cells did not correlate significantly with treatment efficacy. In interrogating bulk RNA seq data from the GTEx, TCGA and KYT databases, IL1RAP was overexpressed in pancreatic cancer compared to normal tissue, with higher expression in advanced stage disease. Moreover, as KRAS mutations promote tumor inflammation and KRASG12D has been implicated in activating the IL-1 axis, we observed that KRASG12D tumors had a higher expression of IL1RAP and IL-1α, but not IL-1β, compared to KRAS-wildtype tumors. In both early and late-stage PDAC, high levels of IL1RAP strongly correlated with poor survival (both p&amp;lt;0.0001). Patients responding to GN tended to have lower IL1RAP levels than patients with progressive or stable disease, in stark contrast to the results with nadunolimab/GN. To understand the effects of nadunolimab/GN in the TME, spatial transcriptomics in screening and on-treatment biopsies are being analyzed with Nanostring GeoMx. Conclusion: IL1RAP is upregulated in pancreatic cancer, its expression correlates with oncogenic KRAS driver mutations and is strongly associated with poor survival. The IL1RAP-targeting antibody nadunolimab has shown promising target-dependent efficacy in combination with 1st line chemotherapy, indicating that IL1RAP is a both highly relevant and targetable protein in PDAC. Citation Format: Eric Van Cutsem, Kawther Abdilleh, Jashodeep Datta, Manuel Hidalgo, Camilla Rydberg Millrud, Petter Skoog, Annika Sanfridson, Dominique Tersago, David Liberg. Interleukin-1 receptor accessory protein (IL1RAP) overexpression is associated with worse prognosis in PDAC and is targetable by nadunolimab [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C002.

CD3-CD8 immune score associated with a clinical score stratifies PDAC prognosis regardless of adjuvant or neoadjuvant chemotherapy

ABSTRACT Stratification of the prognosis of pancreatic cancer (PDAC) patients treated by surgery is based solely on clinical variables, such as tumor stage and node status. The development of biomarkers of relapse is needed, especially to drive administration of adjuvant therapy in this at-risk population. Our study evaluates the prognostic performance of a CD3- and CD8-based immune score. CD3, CD8 and Foxp3 expression were evaluated on whole slides in two retrospective PDAC cohorts totaling 334 patients. For this study, we developed an immune score to estimate CD3 and CD8 infiltration in both tumor core and invasive margin using computer-guided analysis with QuPath software. Variables were combined in a dichotomous immune score. The association between immune and clinical scores, and both PFS and OS was investigated. We observed that a dichotomous immune score predicts both PFS and OS of localized PDAC. By univariate and multivariate analysis, immune score, tumor grade, adjuvant therapy, lymph node status, and adjuvant chemotherapy administration were associated with PFS and OS. We subsequently associated the PDAC immune score and clinical variables in a combined score. This combined score predicted patient outcomes independently of adjuvant or neoadjuvant treatment, and improved patient prognostic prediction compared to clinical variables or immune score alone.

A protein-based prognostic model for pancreatic ductal adenocarcinoma: Construction and validation

BackgroundProbing relevant proteomic biomarkers may facilitate effective pancreatic adenocarcinoma (PDAC) diagnosis, treatment and prevention. Here, we developed a protein-based prognostic model for PDAC by using relevant proteomic biomarkers data from The Cancer Genome Atlas (TCGA). MethodsWe obtained PDAC's proteomic and clinical data from TCGA and used various analytical tools to identify differentially expressed proteins between normal and cancer tissues. We constructed our protein-based prognostic model and confirmed its accuracy using receiver operating characteristic curve and Kaplan-Meier survival analyses. We elucidated clinical factor-signature protein correlations by clinical correlation assessments and protein coexpression networks. We also used immunohistochemistry (protein expression assessment), Gene Set Enrichment Analysis (protein role identification) and CIBERSORT (infiltrating immune cell distribution assessment). ResultsCIITA, BRAF_pS445, AR, YTHDF2, IGFBP2 and CDK1_pT14 were identified as PDAC-associated prognostic proteins. All risk scores calculated using our model provided 1-, 3-, 5-year survival probability at 70 % accuracy. The reliability of our model was validated by the GEO as well. In high- and low-risk groups, age, sex, T- and N- stage disparities were significant, and prognostic and coexpressed proteins correlated. PDAC tissues demonstrated significant CDK1_pT14 overexpression but significant BRAF_pS445, YTHDF2, and IGFBP2 underexpression. Downstream proteins of BRAF were validated by IHC. Low-risk tissues demonstrated more naïve B cells, eosinophils, activated NK cells and regulatory T cells, whereas high-risk tissues demonstrated more activated memory T cells, monocytes, neutrophils, dendritic cells and resting NK cells. ConclusionsOur protein-based prognostic model for PDAC, along with six signature proteins, might aid in predicting PDAC prognosis and therapeutic targets.

Identification of Family with Sequence Similarity 110 Member C (FAM110C) as a Candidate Diagnostic and Prognostic Biomarker for Glioma.

Gliomas are the most frequent and dangerous primary cerebral tumors. Therefore, there is a need to develop molecular targets for the diagnosis and treatment for glioma. In September 2020, we retrieved the expression matrix of glioblastoma (GBM) sufferers and pertinent clinical data from the TCGA (The Cancer Genome Atlas) database. Prognostic differences between various families with sequence similarity 110 member C (FAM110C) expression groups were assessed by Kaplan-Meier with log-rank test. The R platform get used to assess the accuracy of FAM110C delivery in predicting the prognosis of PDAC using a time-dependent receptor operating characteristic (ROC) curve. The delivery level of FAM110C was determined by qRT-PCR and western blot. Gene set enrichment investigated possible mechanisms between different FAM110C expression groups in GBM (GSEA). The impact of FAM110C on glioma cell movement was discovered using migration test. The drug's gene-targeting impact was validated by the CCK8 test. A total of 173 GBM samples were obtained from the TCGA database, with 148 including information on IDH1 mutations and 151 containing information on overall survival. The mRNA expression level of FAM110C was greater in wild-type GBM, according to qRT-PCR data. The connection between FAM110C expression and Hallmark, GO, and KEGG pathway gene sets was investigated using GSEA software. We used migration test to assess the impact of FAM110C on glioma motility in order to confirm the findings of the GSEA analysis. FAM110C might get used as a possible diagnostic and prognostic biomarker for wild-type GBM, and its inhibition could be used to prevention and treatment wild-type GBM.

Insulin-like Growth Factor II mRNA-Binding Protein 1 Regulates Pancreatic Cancer Cell Growth through the Surveillance of CDC25A mRNA.

A number of data indicate that the sources of different kinds of PDAC may be discovered at the transcription/transduction stage. RNA metabolism is manipulated at various steps by different RNA-binding proteins (RBPs), and the deregulation or irregular activity of RBPs is known to contribute to tumor promotion and progression. The insulin-like growth factor 2 mRNA-binding protein family (IMPs), and IMP1 in particular, has been linked with a poor prognosis in PDAC patients; however, little is known about its contribution in PDAC carcinogenesis. In this study, we investigated the function of IMP1 in PDAC. To evaluate IMP1 expression and correlation with PDAC prognosis, we utilized several public databases. Using a specific siRNA IMP1, we analyzed cell death and cell cycle progression in PDAC cell lines and 3D spheroids. The role of IMP1 was also evaluated in vivo in a Panc-1-derived tumor xenograft murine model. Public data suggest that PDAC patients with higher expression of IMP1 showed poor overall and progression-free survival. IMP1 silencing leads to reduced cell growth in PDAC cells and three-dimensional spheroids. Abrogation of IMP1 in PDAC cells showed lower levels of CDC25A, increased phosphorylation of the cyclin-dependent kinase (CDK)2, and accumulation of PDAC cells in the G1 phase. Immunoprecipitation experiments revealed that IMP1 binds CDC25A mRNA, thus controlling cell-cycle progression. Ultimately, we proved that suppression of IMP1 blocked in vivo growth of Panc-1 transferred into immunodeficient mice. Our results indicate that IMP1 drives the PDCA cell cycle and represents a novel strategy for overcoming PDCA cell proliferation.

SMC3 epigenetic silencing regulates Rab27a expression and drives pancreatic cancer progression

BackgroundPancreatic ductal adenocarcinoma (PDAC) is expected to soon surpass colorectal cancer as a leading cause of cancer mortality in both males and females in the US, only lagging behind lung cancer. The lethality of PDAC is driven by late diagnosis and inefficient therapies. The complex biology of PDAC involves various cellular components, including exosomes that carry molecular information between cells. Thus, recipient cells can be reprogrammed, impacting tumorigenesis. Rab27a is a GTPase responsible for the last step of exosomes biogenesis. Hence, dissecting the mechanisms that regulate the expression of Rab27a and that control exosomes biogenesis can provide fundamental insights into the molecular underpinnings regulating PDAC progression.MethodsTo assess the mechanism that regulates Rab27a expression in PDAC, we used PDAC cell lines. The biological significance of these findings was validated in PDAC genetically engineered mouse models (GEMMs) and human samples.ResultsIn this work we demonstrate in human PDAC samples and GEMMs that Rab27a expression decreases throughout the development of the disease, and that Rab27a knockout promotes disease progression. What is more, we demonstrate that Rab27a expression is epigenetically regulated in PDAC. Treatment with demethylating agents increases Rab27a expression specifically in human PDAC cell lines. We found that SMC3, a component of the cohesin complex, regulates Rab27a expression in PDAC. SMC3 methylation is present in human PDAC specimens and treatment with demethylating agents increases SMC3 expression in human PDAC cell lines. Most importantly, high levels of SMC3 methylation are associated with a worse prognosis in PDAC. Mechanistically, we identified an enhancer region within the Rab27a gene that recruits SMC3, and modulates Rab27a expression.ConclusionOverall, we dissected a mechanism that regulates Rab27a expression during PDAC progression and impacts disease prognosis.

PITX2 in pancreatic stellate cells promotes EMT in pancreatic cancer cells via the Wnt/β-catenin pathway.

Since the prognosis of patients with pancreatic cancer is very poor and there is a lack of treatment methods, this study is performed to investigate the function of PITX2 in pancreatic stellate cells (PSCs) in the progression of pancreatic cancer. Scientific hypotheses are proposed according to bioinformatics analysis and tissue microarray analysis. Stable knockdown of PITX2 in PSCs is achieved through lentiviral infection. The relative expressions of PITX2, α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are measured in wild-type PSCs and PITX2-knockdown PSCs. Proliferative capacity is measured by EdU assay. After coculture with PSCs, the proliferation, invasion and migration capacity of pancreatic cancer cells are tested. EMT and Wnt/β-catenin downstream genes of pancreatic cancer cells are investigated to reveal the potential mechanism. Bioinformatics analysis reveals that the PITX2 gene is highly expressed in stromal cells in pancreatic cancer and is correlated with squamous-type PDAC. Analysis of PDAC tissue microarray further demonstrates that high PITX2 level in stromal cells is correlated with poor prognosis in PDAC. After stable knockdown of PITX2 in PSCs, the relative protein levels of α-SMA, vimentin, CTNNB1, AXIN1 and LEF1 are decreased, and the proliferative capacity of PSCs is also decreased. After coculture with PSCs, in which PITX2 expression is downregulated, the proliferation, invasion and migration capacities of pancreatic cancer cells are inhibited. Thus, our results show that PITX2-silenced PSCs inhibit the growth, migration and invasion of pancreatic cancer cells via reduced EMT and Wnt/β-catenin signaling.

Acid sphingomyelinase expression is associated with survival in resectable pancreatic ductal adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is one of the most common cancers worldwide. Unfortunately, the prognosis of PDAC is rather poor, and for instance, in the USA, over 47,000 people die because of pancreatic cancer annually. Here, we demonstrate that high expression of acid sphingomyelinase in PDAC strongly correlates with long-term survival of patients, as revealed by the analysis of two independent data sources. The positive effects of acid sphingomyelinase expression on long-term survival of PDAC patients were independent of patient demographics as well as tumor grade, lymph node involvement, perineural invasion, tumor stage, lymphovascular invasion, and adjuvant therapy. We also demonstrate that genetic deficiency or pharmacological inhibition of the acid sphingomyelinase promotes tumor growth in an orthotopic mouse model of PDAC. This is mirrored by a poorer pathologic response, as defined by the College of American Pathologists (CAP) score for pancreatic cancer, to neoadjuvant therapy of patients co-treated with functional inhibitors of the acid sphingomyelinase, in particular tricyclic antidepressants and selective serotonin reuptake inhibitors, in a retrospective analysis. Our data indicate expression of the acid sphingomyelinase in PDAC as a prognostic marker for tumor progression. They further suggest that the use of functional inhibitors of the acid sphingomyelinase, at least of tricyclic antidepressants and selective serotonin reuptake inhibitors in patients with PDAC, is contra-indicated. Finally, our data also suggest a potential novel treatment of PDAC patients with recombinant acid sphingomyelinase.Key messagesPancreatic ductal adenocarcinoma (PDAC) is a common tumor with poor prognosis.Expression of acid sphingomyelinase (ASM) determines outcome of PDAC.Genetic deficiency or pharmacologic inhibition of ASM promotes tumor growth in a mouse model.Inhibition of ASM during neoadjuvant treatment for PDAC correlates with worse pathology.ASM expression is a prognostic marker and potential target in PDAC.

Revealing platelet-related subtypes and prognostic signature in pancreatic adenocarcinoma

BackgroundPancreatic adenocarcinoma (PDAC) is a malignant tumor with high heterogeneity and poor prognosis. In this study, we sought to identify the value of platelet-related genes in prognosis and heterogeneity of PDAC through multiple transcriptomic methods.MethodsBased on datasets from Gene Expression Omnibus and The Cancer Genome Atlas (TCGA), platelet-related genes were screened out, and the TCGA cohort (n = 171) was identified into two subtypes by unsupervised clustering. The platelet-related risk score model (PLRScore) was constructed by univariate Cox and LASSO regression, and the predictive ability was evaluated by Kaplan-Meier test and time-dependent receiver operating characteristic (ROC) curves. The results were validated in two other external validation sets, ICGC-CA (n = 140) and GSE62452 (n = 66). Furthermore, predictive nomogram containing clinical characteristics and PLRScore was established. In addition, we determined the possible correlation between PLRScore and immune infiltration and response of immunotherapy. Finally, we analyzed the heterogeneity of our signature in various types of cells using single-cell analysis.ResultsPlatelet-related subtypes that have significant difference of overall survival and immune states (p < 0.05) were identified. PLRScore model based on four-gene signature (CEP55, LAMA3, CA12, SCN8A) was constructed to predict patient prognosis. The AUCs of training cohort were 0.697, 0.687 and 0.675 for 1-, 3-and 5-year, respectively. Further evaluation of the validation cohorts yielded similar results. In addition, PLRScore was associated with immune cell infiltration and immune checkpoint expression, and had promising ability to predict response to immunotherapy of PDAC.ConclusionsIn this study, the platelet-related subtypes were identified and the four-gene signature was constructed and validated. It may provide new insights into the therapeutic decision-making and molecular targets of PDAC.

Differential expression and bioinformatics analysis of exosome circRNAs in pancreatic ductal adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) is a fatal malignant tumor with an unfavorable prognosis. Increasing evidence indicated circRNAs were associated with the pathogenesis and progression of tumors, but data on the expression of serum exosomal circRNAs in PDAC are scarce. This study attempted to explore the prognostic value and function of serum exosomes in PDAC patients. MethodsMicroarray-based circRNA expression was determined in PDAC and paired with normal serum samples, and the intersection of differentially expressed circRNAs (DECs) in serum exosomal samples and GSE79634 tissue samples was conducted. A specific CircRNA database was applied to investigate DECs binding miRNAs. Target genes were predicted using the R package multiMiR. Cox regression analyses were applied for constructing a prognostic model. The immunological characteristics analysis was carried out through the TIMER, QUANTISEQ, XCELL, EPIC, and ssGSEA algorithms. Results15 DECs were finally identified, and a circRNA-miRNA-mRNA network was established. A prognostic risk model was developed to categorize patients according to the risk scores. Furthermore, the association between risk score and immune checkpoint genes including CD80, TNFSF9, CD276, CD274, LGALS9, and CD44 were significantly elevated in the high-risk group, while ICOSLG and ADORA2A were upregulated in the low-risk group. ConclusionsOur results may provide new clues for the prognosis and treatment of PDAC.

Adjustable extracellular matrix rigidity tumor model for studying stiffness dependent pancreatic ductal adenocarcinomas progression and tumor immunosuppression.

Pancreatic ductal adenocarcinomas (PDAC) is one of the stiffest malignancies with strong solid stresses. Increasing stiffness could alter cellular behavior and trigger internal signaling pathways and is strongly associated with a poor prognosis in PDAC. So far, there has been no report on of an experimental model that can rapidly construct and stably maintain a stiffness gradient dimension in both vitro and in vivo. In this study, a gelatin methacryloyl (GelMA)-based hydrogel was designed for in vitro and in vivo PDAC experiments. The GelMA-based hydrogel has porous, adjustable mechanical properties and excellent in vitro and in vivo biocompatibility. The GelMA-based in vitro 3D culture method can effectively form a gradient and stable extracellular matrix stiffness, affecting cell morphology, cytoskeleton remodeling, and malignant biological behaviors such as proliferation and metastasis. This model is suitable for in vivo studies with long-term maintenance of matrix stiffness and no significant toxicity. High matrix stiffness can significantly promote PDAC progression and tumor immunosuppression. This novel adaptive extracellular matrix rigidity tumor model is an excellent candidate for further development as an in vitro and in vivo biomechanical study model of PDAC or other tumors with strong solid stresses.

Tissue-resident CXCR4+ macrophage as a poor prognosis signature promotes pancreatic ductal adenocarcinoma progression.

Macrophage is an essential part of the tumor immune microenvironment of pancreatic ductal adenocarcinoma. In our study, we explored the CXCR4+ macrophages subset on its prognosis value, immune profile and distinct function in pancreatic cancer progression. Specimens from 102 postoperative pancreatic patients were analyzed by flow cytometry or immune-fluorescence, and the prognostic value of CXCR4+ macrophages infiltration was further determined by Cox regression. In silico analysis on TCGA, ICGC database and single-cell sequencing of pancreatic ductal adenocarcinoma further validated our findings. We found that high CXCR4+ macrophages infiltration was associated with poor overall survival (P < .01) and disease-free survival (P < .05) as an independent factor. CXCR4+ macrophages exhibited an M2 protumor phenotype with high expression of CD206. The function of CXCR4+ macrophages was further analyzed in the murine orthotopic PDAC model with its tumor promotion effect and inhibition of CD8+ T cells. Mechanistic and RNA-seq analysis showed that CXCR4+ macrophages participated in extracellular matrix remodeling procedures and especially secreted SPARC through CXCR4/PI3K/Akt pathway promoting tumor proliferation and migration. Our study reveals that CXCR4+ macrophages infiltration is an indicator of poor prognosis of PDAC and targeting these cells was potentially crucial in immunotherapy of PDAC.

FASN multi-omic characterization reveals metabolic heterogeneity in pancreatic and prostate adenocarcinoma

BackgroundPancreatic ductal adenocarcinoma (PDAC) and prostate cancer (PCa) are among the most prevalent malignant tumors worldwide. There is now a comprehensive understanding of metabolic reprogramming as a hallmark of cancer. Fatty acid synthase (FASN) is a key regulator of the lipid metabolic network, providing energy to favor tumor proliferation and development. Whereas the biological role of FASN is known, its response and sensitivity to inhibition have not yet been fully established in these two cancer settings.MethodsTo evaluate the association between FASN expression, methylation, prognosis, and mutational profile in PDAC and PCa, we interrogated public databases and surveyed online platforms using TCGA data. The STRING database was used to investigate FASN interactors, and the Gene Set Enrichment Analysis platform Reactome database was used to perform an enrichment analysis using data from RNA sequencing public databases of PDAC and PCa. In vitro models using PDAC and PCa cell lines were used to corroborate the expression of FASN, as shown by Western blot, and the effects of FASN inhibition on cell proliferation/cell cycle progression and mitochondrial respiration were investigated with MTT, colony formation assay, cell cycle analysis and MitoStress Test.ResultsThe expression of FASN was not modulated in PDAC compared to normal pancreatic tissues, while it was overexpressed in PCa, which also displayed a different level of promoter methylation. Based on tumor grade, FASN expression decreased in advanced stages of PDAC, but increased in PCa. A low incidence of FASN mutations was found for both tumors. FASN was overexpressed in PCa, despite not reaching statistical significance, and was associated with a worse prognosis than in PDAC. The biological role of FASN interactors correlated with lipid metabolism, and GSEA indicated that lipid-mediated mitochondrial respiration was enriched in PCa. Following validation of FASN overexpression in PCa compared to PDAC in vitro, we tested TVB-2640 as a FASN inhibitor. PCa proliferation arrest was modulated by FASN inhibition in a dose- and time-dependent manner, whereas PDAC proliferation was not altered. In line with this finding, mitochondrial respiration was found to be more affected in PCa than in PDAC. FASN inhibition interfered with metabolic signaling causing lipid accumulation and affecting cell viability with an impact on the replicative processes.ConclusionsFASN exhibited differential expression patterns in PDAC and PCa, suggesting a different evolution during cancer progression. This was corroborated by the fact that both tumors responded differently to FASN inhibition in terms of proliferative potential and mitochondrial respiration, indicating that its use should reflect context specificity.