Pancreatic Adenocarcinoma Tumors Research Articles

Identification of pancreatic adenocarcinoma immune subtype associated with tumor neoantigen from aberrant alternative splicing.

Pancreatic adenocarcinoma (PAAD) is referred to as an immunologically "cold" tumor that responds poorly to immunotherapy. A fundamental theory that explains the low immunogenicity of PAAD is the dramatically low tumor mutation burden (TMB) of PAAD tumors, which fails to induce sufficient immune response. Alternative splicing of pre-mRNA, which could alter the proteomic diversity of many cancers, has been reported to be involved in neoantigen production. Therefore, we aim to identify novel PAAD antigens and immune subtypes through systematic bioinformatics research. Data for splicing analysis were downloaded from The Cancer Genome Atlas (TCGA) SpliceSeq database. Among the available algorithms, we chose CIBERSORT to evaluate the immune cell distribution among PAADs. The TCGA-PAAD expression matrix was used to construct a co-expression network. Single-cell analysis was performed based on the Seurat workflow. Integrated analysis of aberrantly upregulated genes, alternatively spliced genes, genes associated with nonsense-mediated RNA decay (NMD) factors, antigen presentation and overall survival (OS) in TCGA-PAAD revealed that PLEC is a promising neoantigen for PAAD-targeted therapy. We identified a C2 TCGA-PAAD subtype that had better prognosis and more CD8+ T-cell infiltration. We propose a novel immune subtyping system for PAAD to indicate patient prognosis and opportunities for immunotherapy, such as immune checkpoint (ICP) inhibitors. In conclusion, the present study used a transcriptome-guided approach to screen neoantigen candidates based on alternative splicing, NMD factors, and antigen-presenting signatures for PAAD. A prognosis model with guidance of immunotherapy will aid in patient selection for appropriate treatment.

SPDEF drives pancreatic adenocarcinoma progression via transcriptional upregulation of S100A16 and activation of the PI3K/AKT signaling pathway.

Pancreatic adenocarcinoma (PAAD) is a notably aggressive malignancy with limited treatment options and an unfavorable prognosis for patients. We aimed to investigate molecular mechanisms by which Sam's pointed domain-containing ETS transcription factor (SPDEF) exerts effects on PAAD progression. We analyzed differentially expressed genes (DEGs) and their integration with ETS family members using the The Cancer Genome Atlas (TCGA) database, hence identifying SPDEF as a core gene in PAAD. Kaplan-Meier survival analysis confirmed SPDEF's prognostic potential. In vitro experiments validated the association with cell proliferation and apoptosis, affecting pancreatic cancer cell dynamics. We detected increased SPDEF expression in PAAD tumor samples. Our in vitro studies revealed that SPDEF regulates mRNA and protein expression levels, and significantly affects cell proliferation. Moreover, SPDEF was associated with reduced apoptosis and enhanced cell migration and invasion. In-depth analysis of SPDEF-targeted genes revealed four crucial genes for advanced prognostic model, among which S100A16 was significantly correlated with SPDEF. Mechanistic analysis showed that SPDEF enhances the transcription of S100A16, which in turn enhances PAAD cell migration, proliferation, and invasion by activating the PI3K/AKT signaling pathway. Our study revealed the critical role of SPDEF in promoting PAAD by upregulating S100A16 transcription and stimulating the PI3K/AKT signaling pathway. This knowledge deepened our understanding of pancreatic cancer's molecular progression and unveiled potential therapeutic strategies targeting SPDEF-driven pathways.

Identification of novel potential homologous repair deficiency-associated genes in pancreatic adenocarcinoma via WGCNA coexpression network analysis and machine learning

ABSTRACT Homologous repair deficiency (HRD) impedes double-strand break repair, which is a common driver of carcinogenesis. Positive HRD status can be used as theranostic markers of response to platinum- and PARP inhibitor-based chemotherapies. Here, we aimed to fully investigate the therapeutic and prognostic potential of HRD in pancreatic adenocarcinoma (PAAD) and identify effective biomarkers related to HRD using comprehensive bioinformatics analysis. The HRD score was defined as the unweighted sum of the LOH, TAI, and LST scores, and it was obtained based on the previous literature. To characterize PAAD immune infiltration subtypes, the “ConsensusClusterPlus” package in R was used to conduct unsupervised clustering. A WGCNA was conducted to elucidate the gene coexpression modules and hub genes in the HRD-related gene module of PAAD. The functional enrichment study was performed using Metascape. LASSO analysis was performed using the “glmnet” package in R, while the random forest algorithm was realized using the “randomForest” package in R. The prognostic variables were evaluated using univariate Cox analysis. The prognostic risk model was built using the LASSO approach. ROC curve and KM survival analyses were performed to assess the prognostic potential of the risk model. The half-maximal inhibitory concentration (IC50) of the PARP inhibitors was estimated using the “pRRophetic” package in R and the Genomics of Drug Sensitivity in Cancer database. The “rms” package in R was used to create the nomogram. A high HRD score indicated a poor prognosis and an advanced clinical process in PAAD patients. PAAD tumors with high HRD levels revealed significant T helper lymphocyte depletion, upregulated levels of cancer stem cells, and increased sensitivity to rucaparib, Olaparib, and veliparib. Using WGCNA, 11 coexpression modules were obtained. The red module and 122 hub genes were identified as the most correlated with HRD in PAAD. Functional enrichment analysis revealed that the 122 hub genes were mainly concentrated in cell cycle pathways. One novel HRD-related gene signature consisting of CKS1B, HJURP, and TPX2 were screened via LASSO analysis and a random forest algorithm, and they were validated using independent validation sets. No direct association between HRD and CKS1B, HJURP, or TPX2 has not been reported in the literature so far. Thus, these findings indicated that CKS1B, HJURP, and TPX2 have potential as diagnostic and prognostic biomarkers for PAAD. We constructed a novel HRD-related prognostic model that provides new insights into PAAD prognosis and immunotherapy. Based on bioinformatics analysis, we comprehensively explored the therapeutic and prognostic potential of HRD in PAAD. One novel HRD-related gene signature consisting of CKS1B, HJURP, and TPX2 were identified through the combination of WGCNA, LASSO analysis and a random forest algorithm. A novel HRD-related risk model that can predict clinical prognosis and immunotherapeutic response in PAAD patients was constructed.

Increasing cancer genetic referrals via best practice alerts (BPA).

565 Background: Germline genetic testing (GT) is recommended for all patients (pts) with pancreatic cancer (PC). However, genetic referral (GR) rates for PC are low even at academic centers; there is a paucity of literature at safety-net hospitals (SNH) which often treat higher percentages of cancers at advanced stages. Providers focused on the challenging treatment of PC and may not prioritize GT referrals. Technology can be adapted to aid in this process. Best practice alerts (BPA) built in Electronic Medical Records (EMR) can prompt providers to place GR order. We initiated BPA at John Peter Smith (JPS) hospital, a SNH in Texas, and evaluated if the BPA improved referral patterns. Methods: A retrospective review was conducted using JPS tumor registry data. We studied pts diagnosed with pancreatic adenocarcinoma (AC) or neuroendocrine tumors (NET) from 1/1/2018 to 4/30/2023 at JPS. BPA go-live date was 10/19/2022. Data Analytics team queried EMR regarding GR, if pts completed their genetics encounter (GE), and GT. Statistical analysis using a two-tailed T test was performed. Results: 162 PC pts were identified: 155 (96%) AC and 7 (4%) NET, and the median age was 59 years. A majority of patients were diagnosed in house (114/162, 70%), while the rest were referred to JPS after diagnosis elsewhere. A total of 57 pts were excluded due to being placed on hospice, death within 3 months of diagnosis, or refusing oncology services at JPS. 105 pts were included for analyses: 96 were diagnosed with PC before the BPA go-live date (pre-BPA) and 9 after the BPA go-live date (post-BPA). 36 (38%) pts were referred pre-BPA. 23 pre-BPA pts completed GE, median of 15 days from referral. 7 out of 9 (78%) pts received GR post-BPA. Post-BPA pts were all referred due to BPA triggers being fired. 2 post-BPA pts completed GE with a median time of 27.5 days from GR. Since launching the BPA, a statistically significant increase in GR has been observed (p=0.0187). 2 pre-BPA pts who completed GT were found to have a pathogenic variant. Conclusions: BPA has shown a significant improvement in GR for PC. Our study population is limited by rarity of PC, and the BPA alert is set to only fire for pts receiving oncology care at JPS. We noted a large number of pre-BPA pts that have yet to be referred and remain at risk. Updates to the BPA build are needed to capture previously diagnosed pts who are receiving JPS oncology services. For future studies, we will analyze pts with other cancer diagnoses to continue to improve upon the GR process.[Table: see text]

High WFDC3 gene expression is associated with poor prognosis and reduced immune cells infiltration in pancreatic adenocarcinoma: A study using the TCGA database and bioinformatics analysis.

Whey-acidic-protein (WAP) four-disulfide core domain protein 3 (WFDC3) is one of the WAP family proteins. This protein family is associated with the development of solid tumors and affects the tumor immunological microenvironment. However, the prognostic value of WFDC3 in pancreatic adenocarcinoma (PAAD) and its effect on the tumor immune microenvironment is yet to be clarified. The Cancer Genome Atlas database and Genotype-Tissue Expression database were used to analyze the differential expression of WFDC3 between the tumor and adjacent tissues. The clinical significance of WFDC3 was analyzed in The Cancer Genome Atlas and International Cancer Genome Consortium database using WFDC3 transcripts and clinical information. In order to elucidate the underlying mechanisms, gene set enrichment analysis was conducted to determine potential activated pathways. Immune score evaluation and publicly available pharmacogenomics database [the Genomics of Drug Sensitivity in Cancer] were utilized to quantify immune cell infiltration and the effect on chemotherapeutic drug sensitivity. WFDC3 levels were higher in PAAD tissues than in normal pancreatic tissues. High levels of WFDC3 expression progressively increased as PAAD tumor stages progressed. Patients with elevated WFDC3 expression showed a poor prognosis. The gene set enrichment analysis analysis revealed that glutamate, arginine, and proline, and histidine metabolism levels were elevated in patients with a high WFDC3 expression phenotype. B, CD4+ T, and CD8+ T cell infiltration was diminished in PAAD tissues with elevated WFDC3 expression. According to pharmacogenomics, PAAD tissues with high WFDC3 expression are susceptible to gemcitabine. WFDC3 is highly expressed in PAAD, and patients with a high level of WFDC3 expression have a shorter overall survival time, indicating a poorer prognosis. High expression of WFDC3 may lead to the development of PAAD by affecting the amino acid metabolism and the tumor immunological microenvironment. WFDC3 may serve as a potential diagnostic and prognostic biomarker for PAAD patients.

An Unusual Case of Dual Pancreatic Tumors

ABSTRACT We report a simultaneous occurrence of pancreatic adenocarcinoma and pancreatic neuroendocrine tumor. A 64-year-old woman presented with abdominal pain and weight loss. Abdominal computed tomography revealed a pancreatic head mass with a mesenteric artery encasement. Endoscopic ultrasound revealed a second mass in the tail of the pancreas. Pathology reported adenocarcinoma of the head of the pancreas and a neuroendocrine tumor in the tail of the pancreas. The neuroendocrine tumor was nonfunctional, with no symptoms or signs present on assessment. The patient had advanced unresectable carcinoma, so she was treated with chemotherapy.

Gamma Secretase Inhibition Sensitizes Pancreatic Adenocarcinoma Tumors to RT In Vivo

Pancreatic adenocarcinoma (PDAC) is an extremely aggressive cancer that lacks curative treatment options. Almost half of patients present with unresectable disease limiting treatment to non-curative options. Patients treated with neoadjuvant radiation therapy (RT) exhibit increases in fibrosis and epithelial-to-mesenchymal transition (EMT). ADAM10, an extracellular sheddase, can stimulate stromal fibrosis, EMT, and radioresistance. ADAM10 also mediates EMT through Notch signaling by cleaving its extracellular domain. Further cleavage by gamma secretase produces the Notch intracellular domain (NICD), which translocates to the nucleus and activates downstream transcriptional targets. Here, we explore whether inhibition of Notch cleavage by gamma secretase radiosensitizes PDAC tumors. Bilateral flank subcutaneous PDAC isografts were produced in 40 mice using PK5L1940 KPC cells. Intraperitoneal injections of the gamma secretase inhibitor, DAPT (5 mg/kg), were delivered daily for 7 days, starting 3 days prior to RT. A single dose of 20 Gy was administered to each flank tumor, and volumes were measured twice weekly. Colony formation assays of KPC cells were performed after RT, in the presence or absence of DAPT. Since stromal fibrosis can mediate radio-resistance in the tumor microenvironment (TME), the effect of tumor cells on Notch pathway activation in mouse fibroblasts (3T3 cells) was investigated using a luciferase reporter assay. Thus, 3T3 cells transfected with a Notch pathway luciferase reporter were incubated with PDAC cells for 48 h, followed by measurement of luciferase activity. In vivo, the combination of DAPT and RT significantly delayed tumor growth, and some tumors were completely eradicated. Mean tumor size for the combination at 21 days was 21 mm3 (range = 0-53, p = 0.005), while tumor size was 577 mm3 (range = 217-955, p = 0.69) for DAPT alone, 435 mm3 for RT alone (range = 51-932, p = 0.79), and 367 mm3 for untreated vehicle (range = 97-1144). Surprisingly, DAPT did not reduce clonogenic survival in vitro. Both ADAM10 knockout and DAPT decreased NICD cleavage and transcription of the downstream target Hes1 in vivo and in vitro. Co-culture with PDAC cells increased Notch luciferase reporter activity in fibroblasts. This effect was not mimicked by PDAC-conditioned media, suggesting a requirement for intercellular contact. Notch pathway inhibition sensitizes PDAC tumors to RT in vivo, but not in vitro, suggesting involvement of the TME. Indeed, co-culture with PDAC cells stimulates notch signaling in fibroblasts, suggesting non-cell autonomous mechanisms mediating fibrosis in the TME driving radioresistance. Future studies will determine if ADAM10 inhibition targeting PDAC cells and/or gamma secretase inhibition targeting the TME enhances radiation sensitivity in vivo by blocking fibroblast Notch signaling.

Laminin 332 expression levels predict clinical outcomes and chemotherapy response in patients with pancreatic adenocarcinoma.

Poor outcomes and chemotherapy resistance for patients with pancreatic adenocarcinoma (PAAD) are a challenge worldwide, and new or improved prognostic biomarkers are urgently required. Individual laminin family members have been established as cancer-associated markers, predicting patient outcomes in many cancer types, including PAAD. Here, we used multiple modalities including RNAseq and gene chip, and genomic and proteomic data to examine the relationships of all laminin genes in PAAD with clinical outcomes. These analyses identified that LAMA3, LAMB3, and LAMC2 expression levels are increased at the mRNA and protein levels in PAAD tumours with evidence of co-regulation. Increased expression of all three genes was associated with decreased promoter methylation status, TP53 mutations, and altered receptor tyrosine kinase (RTK) pathways. Clinically, high LAMA3, LAMB3, and LAMC2 transcript abundance was each related to an advanced histological grade. Moreover, high expression of these genes individually predicted poor patient survival, while a signature of combined high expression of LAMA3, LAMB3, and LAMC2 was a stronger predictor of patient outcomes than each gene alone. Interestingly, cell lines with high expression of LM332 chains were not sensitive to the commonly used PAAD chemotherapy drugs paclitaxel and gemcitabine; however, increased sensitivity was evident for erlotinib, afatinib, gefitinib, and cetuximab epidermal growth factor (EGFR) RTK inhibitors. To explore possible mechanisms, we investigated co-expressed genes, identifying eight hub genes, namely, GJB3, ITGB6, SERPINB5, GPRC5A, PLEK2, TMPRSS4, P2RY2, and TRIM29, which are co-expressed with all three of LAMA3, LAMB3, and LAMC2. Of these, only SERPINB5 provided a stronger predictive value than the laminin-encoding genes. Together, these multiple integrated analyses suggest that the combined expression of LM332 is a useful prognostic biomarker for PAAD and could help patient stratification and therapeutic selection.

TMPOP2 Inhibition Suppresses Pancreatic Cancer Cell Migration and Development by Repressing The JNK/STAT3 Pathway.

Pancreatic cancer is a malignancy with a poor prognosis and high mortality. The lincRNA TMPOP2 is highly expressed in gynecological cancers and may exhibit tumor-promoting functions. However, the function of TMPOP2 in pancreatic cancer is limited. TMPOP2 expression in pancreatic cancer and adjacent tissues is analyzed from The Cancer Genome Atlas (TCGA) and GTEx database. It shows the high expression of TMPOP2 in pancreatic cancer tissues. Similar results are observed in resected pancreatic adenocarcinoma tumors and adjacent tissues from 20 patients and the relative cell lines. When the pancreatic cell lines aretransfected with si-TMPOP2, it shows that TMPOP2 downregulation inhibits the cells migration and EMT. Furthermore, the potential mechanism isexplored by detecting the expression of c-Jun N-terminal kinase (JNK), phosphorylated JNK, signal transducer and activator of transcription 3 (STAT3), and phosphorylated STAT3. It suggests that TMPOP2 knockdown inactivates JNK and STAT3 phosphorylation. When a JNK activator (anisomycin) is added to the cells with si-NC or si-TMPOP2, it canpartially reverse the migration and EMT inhibition of the cells with inhibited TMPOP2. TMPOP2 inhibition suppresses the migration and EMT of pancreatic cancer by repressing the JNK/STAT3 pathway. Thus, this may be a novel target for pancreatic cancer therapy.

Mapping estimates of vascular permeability with a clinical indocyanine green fluorescence imaging system in experimental pancreatic adenocarcinoma tumors.

Pancreatic cancer tumors are known to be avascular, but their neovascular capillaries are still chaotic leaky vessels. Capillary permeability could have significant value for therapy assessment, and its quantification might be possible with macroscopic imaging of indocyanine green (ICG) kinetics in tissue. The capacity of using standard fluorescence surgical systems for ICG kinetic imaging as a probe for capillary leakage was evaluated using a clinical surgical fluorescence imaging system, as interpreted through vascular permeability modeling. Xenograft pancreatic adenocarcinoma models were imaged in mice during bolus injection of ICG to capture the kinetics of uptake. Image analysis included ratiometric data, normalization, and match to theoretical modeling. Kinetic data were converted into the extraction fraction of the capillary leakage. Pancreatic tumors were usually less fluorescent than the surrounding healthy tissues, but still the rate of tumor perfusion could be assessed to quantify capillary extraction. Model simulations showed that flow kinetics stabilized after about 1min beyond the initial bolus injection and that the relative extraction fraction model estimates matched the experimental data of normalized uptake within the tissue. The kinetics in the time period of 1 to 2min post-injection provided optimal differential data between AsPC1 and BxPC3 tumors, although high individual variation exists between tumors. ICG kinetic imaging during the initial leakage phase was diagnostic for quantitative vascular permeability within pancreatic tumors. Methods for autogain correction and normalized model-based interpretation allowed for quantification of extraction fraction and difference identification between tumor types in early timepoints.

Anoikis-Related Gene Signature for Prognostication of Pancreatic Adenocarcinoma: A Multi-Omics Exploration and Verification Study

Anoikis, a form of apoptosis that occurs due to detachment of cells from the extracellular matrix, has been linked to the development of cancer in several studies. However, its role in pancreatic cancer remains incompletely understood. In this study, we utilized univariate Cox regression and LASSO regression analyses to establish a prognostic model for pancreatic adenocarcinoma based on anoikis-related genes in the TCGA database. Additionally, we performed univariate and multifactorial Cox analyses of protein expression results for TCGA pancreatic adenocarcinoma. We further explored the difference in immune infiltration between the high-risk and low-risk groups and verified the expression of the screened genes using quantitative real-time PCR (qRT-PCR). Our findings indicate that numerous anoikis-related genes are linked to pancreatic adenocarcinoma prognosis. We identified seven prognostic genes (MET, DYNLL2, CDK1, TNFSF10, PIP5K1C, MSLN, GKN1) and validated that their related proteins, such as EGFR and MMP2, have a significant impact on the prognosis of pancreatic adenocarcinoma. Based on clustering analyses of the seven prognostic genes, patients could be classified into three distinct categories, for which somatic mutations varied significantly across the groups. High-risk and low-risk groups also exhibited significant differences in immune infiltration. All genes were found to be highly expressed in pancreatic cancer cell lines (ASPC-1, CFPAC-1) as compared to a normal pancreatic cell line (HPDE). Based on the seven anoikis-related genes, we formulated a robust prognostic model with high predictive accuracy. We also identified the significant impact of KRAS, P53, and CDKN2A mutations on the prognosis of this fatal disease. Therefore, our study highlights the crucial role of anoikis in the development of the pancreatic adenocarcinoma tumor microenvironment.

Analysis of systemic immune changes in patients with advanced cancer treated with immunotoxin LMB-100 and tofacitinib.

e15017 Background: LMB-100 recombinant immunotoxin delivers a modified Pseudomonas exotoxin A payload to mesothelin-expressing tumors. Almost all patients receiving LMB-100 develop anti-drug antibodies (ADAs) after 2 cycles/ 6 doses of the drug, therefore reducing peak serum drug concentrations to near the lower limit of detection. Tofacitinib is an oral JAK inhibitor that had been shown to prevent ADA formation in pre-clinical studies. Apart from assessing safety and tolerability, this trial sought to determine whether co-administration of tofacitinib with LMB-100 delays the formation of neutralizing ADAs so more patients could achieve the peak LMB-100 concentration of > 600 ng/mL during treatment cycle 2. Correlative data examining circulating immune cell subsets and cytokines pre- and on-treatment are presented here. Methods: Patients with pancreatic adenocarcinoma (n = 13) and other mesothelin-expressing solid tumors (n = 3; cholangiocarcinoma, appendix, cystadenocarcinoma) were treated for up to 3 cycles (21 days) with LMB-100 given on days 4, 6, and 8 at 2 dose levels (100 and 140 mcg/kg), accompanied by oral tofacitinib for the first 10 days of the cycle (10 mg BID). Adverse events were assessed as per CTCAE 5.0. Analysis of the cytokine data was performed using a Wilcoxon signed-rank test. Results: DLTs of grade 3 cardiac toxicity (n = 1) and grade 4 hyponatremia (n = 1) were seen at the 140mcg/kg dose of LMB-100. One patient treated at 100 mcg/kg developed a grade 4 pericardial effusion, resulting in early closure of the study for safety. The two patients who experienced cardiac toxicity had lower baseline CD4+ cells and increased CD19+ cells post-LMB-100 treatment. Four out of 8 evaluable patients achieved LMB-100 concentration above the threshold during cycle 2, and 2 out of 3 did so during cycle 3. Analysis of peripheral blood cytokine levels showed sustained increases in TNF-α, IL-8, and IL-10 following LMB-100 administration through to the start of cycle 2. Percentage of Tregs increased through cycle 1 in patients who developed drug-neutralizing ADAs and was significantly higher than in patients with LMB-100 levels above threshold at the start of cycle 2. Conclusions: Combination of LMB-100 with tofacitinib is not safe. An insufficient number of patients was treated to conclusively assess the ability of tofacitinib to stop or delay ADA formation. Increases in circulating Tregs were observed in patients with early neutralizing ADA formation. Clinical trial information: NCT04034238 .

Analysis and validation of the potential of the MYO1E gene in pancreatic adenocarcinoma based on a bioinformatics approach.

Pancreatic adenocarcinoma (PAAD) is a common digestive cancer, and its prognosis is poor. Myosin 1E (MYO1E) is a class I myosin family member whose expression and function have not been reported in PAAD. In the present study, bioinformatics analysis was used to explore the expression levels of MYO1E in PAAD and its prognostic value, and the immunological role of MYO1E in PAAD was analyzed. The study revealed that a variety of malignancies have substantially increased MYO1E expression. Further investigation demonstrated that PAAD tissues exhibited greater levels of MYO1E mRNA and protein expression than normal tissues. High MYO1E expression is associated with poor prognosis in patients with PAAD. MYO1E expression was also associated with pathological stage in patients with PAAD. Functional enrichment analysis demonstrated that MYO1E was linked to multiple tumor-related mechanisms in PAAD. The pancreatic adenocarcinoma tumor microenvironment (TME) was analyzed and it was revealed that MYO1E expression was positively associated with tumor immune cell infiltration. In addition, MYO1E was closely associated with some tumor chemokines/receptors and immune checkpoints. In vitro experiments revealed that the suppression of MYO1E expression could inhibit pancreatic adenocarcinoma cell proliferation, invasion and migration. Through preliminary analysis, the present study evaluated the potential function of MYO1E in PAAD and its function in TME, and MYO1E may become a potential biomarker for PAAD.

EUS-guided fine needle biopsy is able to provide diagnosis in rare osteoclast-like giant cells undifferentiated carcinoma of the pancreas: Report of two cases.

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UC-OGC) is a rare subtype of pancreatic cancer, accounting for less than 1% of all pancreatic tumors. Preoperative diagnosis is cumbersome as cross-sectional imaging is often not capable to distinguish between UCOGC and other pancreatic tumors such as pancreatic adenocarcinoma, mucinous carcinoma or neuroendocrine tumors and specific tumor markers seem to be lacking. Endoscopic ultrasound r `m(EUS) with tissue acquisition via fine-needle aspiration (FNA) or biopsy (FNB) with microscopic HE staining and immunohistochemistry allows for an accurate diagnosis, thus influencing further treatment. We present herein the cases of two patients with osteoclast-like giant cells tumors of the pancreas diagnosed by EUS-guided fine needle biopsy and perform a literature review on the role of EUS-guided biopsy for diagnosis.

The Tumor Coagulome as a Transcriptional Target and a Potential Effector of Glucocorticoids in Human Cancers

The coagulome, defined as the repertoire of genes that locally regulate coagulation and fibrinolysis, is a key determinant of vascular thromboembolic complications of cancer. In addition to vascular complications, the coagulome may also regulate the tumor microenvironment (TME). Glucocorticoids are key hormones that mediate cellular responses to various stresses and exert anti-inflammatory effects. We addressed the effects of glucocorticoids on the coagulome of human tumors by investigating interactions with Oral Squamous Cell Carcinoma, Lung Adenocarcinoma, and Pancreatic Adenocarcinoma tumor types. We analyzed the regulation of three essential coagulome components, i.e., the tissue factor (TF), urokinase-type plasminogen activator (uPA), and plasminogen activator inhibitor-1 (PAI-1) in cancer cell lines exposed to specific agonists of the glucocorticoid receptor (GR) (dexamethasone and hydrocortisone). We used QPCR, immunoblots, small-interfering RNA, Chromatin immunoprecipitation sequencing (ChIPseq) and genomic data from whole tumor and single-cell analyses. Glucocorticoids modulate the coagulome of cancer cells through a combination of indirect and direct transcriptional effects. Dexamethasone directly increased PAI-1 expression in a GR-dependent manner. We confirmed the relevance of these findings in human tumors, where high GR activity/high SERPINE1 expression corresponded to a TME enriched in active fibroblasts and with a high TGF-β response. The transcriptional regulation of the coagulome by glucocorticoids that we report may have vascular consequences and account for some of the effects of glucocorticoids on the TME.

Systematic review, meta-analysis and single-centre experience of the diagnostic accuracy of intraoperative near-infrared indocyanine green-fluorescence in detecting pancreatic tumours.

During pancreatic resections assessing tumour boundaries and identifying the ideal resection margins can be challenging due to the associated pancreatic gland inflammation and texture. This is particularly true in the context of minimally invasive surgery, where there is a very limited or absent tactile feedback. Indocyanine green (ICG) fluorescence imaging can assist surgeons by simply providing valuable real-time intraoperative information at low cost with minimal side effects. This meta-analysis summarises the available evidence on the use of near-infrared fluorescence imaging with ICG for the intraoperative visualization of pancreatic tumours (PROSPERO ID: CRD42021247203). MEDLINE, Embase, and Web Of Science electronic databases were searched to identify manuscripts where ICG was intravenously administered prior to or during pancreatic surgery and reporting the prevalence of pancreatic lesions visualised through fluorescence imaging. Six studies with 7 series' reporting data on 64 pancreatic lesions were included in the analysis. MINOR scores ranged from 6 to 10, with a median of 8. The most frequent indications were pancreatic adenocarcinoma and neuroendocrine tumours. In most cases (67.2%) ICG was administered during surgery. ICG fluorescence identified 48/64 lesions (75%) with 81.3% accuracy, 0.788 (95%CI 0.361-0.961) sensitivity, 1 (95%CI 0.072-1) specificity and positive predictive value of 0.982 (95%CI 0.532-1). In line with the literature, ICG fluorescence identified 5/6 (83.3%) of pancreatic lesions during robotic pancreatic resections performed at our Institution. This meta-analysis is the first summarising the results of ICG immunofluorescence in detecting pancreatic tumours during surgery, showing good accuracy. Additional research is needed to define optimal ICG administration strategies and fluorescence intensity cut-offs.

Mitophagy-mediated molecular subtypes depict the hallmarks of the tumour metabolism and guide precision chemotherapy in pancreatic adenocarcinoma.

Background: Mitophagy is closely related to cancer initiation and progression. However, heterogeneity with reference to mitophagy remains unexplored in pancreatic adenocarcinoma (PAAD). Materials and methods: We used Reactome database to download the mitophagy-related, glycolysis-related and cholesterol biosynthesis-related signaling pathways. Unsupervised clustering using the “ConsensusClusterPlus” R package was performed to identify molecular subtypes related to mitophagy and metabolism. Prognosis-related mitophagy regulators were identified by univariate Cox regression analysis. Receiver operating characteristics (ROC) and Kaplan-Meier (K-M) survival analyses were used to assess the diagnostic and prognostic role of the hub genes and prognosis risk model. Weighted gene co-expression network analysis (WGCNA) was utilized for screening the mitophagy subtype-related hub genes. Metascape was utilized to carry out functional enrichment analysis. The “glmnet” R package was utilised for LASSO, and the “e1071” R package was utilised for SVM. Chemotherapeutic drug sensitivity was estimated using the R package “pRRophetic” and Genomics of Drug Sensitivity in Cancer (GDSC) database. The nomogram was established by the “rms” R package. Results: Three distinct mitophagy subtypes (low, high and intermediate) of PAAD were identified based on the landscape of mitophagy regulators. The high mitophagy subtype had the worst prognosis, highest mRNA expression-based stemness index scores and most hypoxic environment compared to the other subtypes. Additionally, glycolysis and cholesterol biosynthesis were significantly elevated. Three mitophagy subtype-specific gene signatures (CAST, CCDC6, and ERLIN1) were extracted using WGCNA and machine learning. Moreover, PAAD tumours were insensitive to Erlotinib, Sunitinib and Imatinib in the high mitophagy subtype and high CAST, CCDC6, and ERLIN1 expressed subtypes. Furthermore, CAST, CCDC6, and ERLIN1 affected immune cell infiltration (M1 and CD8Tcm), resulting in the altered prognosis of patients with PAAD. A nomogram was constructed to screen patients with the low mitophagy subtype, which showed a higher sensitivity to chemotherapeutic agents. Conclusion: Based on various bioinformatics tools and databases, the PAAD heterogeneity regarding mitophagy was systematically examined. Three different PAAD subtypes having different outcomes, metabolism patterns and chemosensitivity were observed. Moreover, three novel biomarkers that are closely associated with mitophagy and have the potential to guide individualised treatment regimens in PAAD were obtained.

Comparing VIP and PD‐L1 expression as cancer biomarkers

AbstractImmune checkpoint molecules are critical targets of cancer therapies due to their ability to modulate immune responses to cancer. Vasoactive intestinal peptide (VIP) has been proposed as an immune checkpoint molecule, but its predictive and prognostic values have not been established. We evaluated expression levels of VIP and programmed death‐ligand 1 (PD‐L1) across different cancer types and identified specific cancer histologies in which the expression of these markers is elevated. We conducted systematic analyses of the prognostic and predictive values of VIP and PD‐L1 in various cancers using publicly available patient databases and analysis tools including the Gene Expression Profiling Interactive Analysis, PrognoScan, Protein Atlas, cBioportal, and Timer2.0. We also assessed the relationship of PD‐L1 and VIP expression levels with survival and the frequencies of tumor‐infiltrating immune cells in various cancers. We observed a negative correlation between PD‐L1 and VIP expression across cancer types, suggesting the functional redundancy of VIP and PD‐L1 immunosuppressive pathways as mechanisms of immune escape. High expression levels of VIP and the association of VIP expression with immune cell infiltrates in the pancreatic adenocarcinoma tumor microenvironment suggest that VIP may be a predictive biomarker for treating pancreatic adenocarcinoma patients with drugs that inhibit the VIP signaling pathway.

Abstract 2715: Profiling the metabolism of pancreatic adenocarcinoma using a systems medicine-based approach reveals insights into tumor biology, prognosis, and new therapeutic strategies

Abstract Background: One of the hallmarks of cancer is metabolic dysregulation that has been therapeutically targeted with metabolism-based therapies, an important class of chemotherapeutics. However, there has previously been no systematic way to identify key targets for metabolism-based therapeutic interventions. Targeting tumor metabolism has been shown to increase the efficacy of standard chemotherapy in pre-clinical studies. Thus, more efforts need to be put in the discovery of novel targets especially for tumors with poor prognosis and response to chemotherapy, like pancreatic adenocarcinoma. Method: We designed a systems medicine-based technique to understand tumor metabolism in individual patients at a level of detail not previously achievable. We statistically integrated metabolic network modeling with RNA-sequencing data (RNA-seq). This allows us to integrate molecular data about individual tumors (from RNA-seq) with a curated knowledge base of how these molecules interact within a patient’s tumor (using metabolic network models). The result is a mathematical description, or model, of a patient-specific tumor’s metabolism that is able to be interrogated (i.e., it is high-dimensional like RNA-seq data) and able to be simulated (i.e., we can “drug” the model and investigate downstream effects). We applied this technique to 177 pancreatic adenocarcinoma tumor RNA-seq profiles downloaded from The Cancer Genome Atlas to characterize metabolic differences across patients. Results: We found that pancreatic adenocarcinoma tumors tended to be slow growing (median specific growth rate = 0.57 %/day, range = 0-1.4 %/day). This low growth rate helps explain why pancreatic adenocarcinoma tumors are resistant to chemotherapy - there is simply not enough cellular growth for chemo to be effective. However, this result suggests that a small subset of tumors with high growth rate will respond to chemo. In addition, we found that pancreatic adenocarcinoma tumors were separated into three metabolic subtypes: classical, glutamate-addicted, and oxidative. The classical metabolic phenotype tended to have better overall survival than glutamate-addicted or oxidative. Whereas high levels of glutamate metabolism (characterizing the glutamate-addicted tumors) or high levels of oxidative phosphorylation (characterizing the oxidative tumors) were associated with poor overall survival prognosis. Conclusion: Taken together, our systems medicine approach to characterizing patient specific tumor metabolism indicates that a one size fits all approach to chemotherapy in pancreatic adenocarcinoma is likely to fail; and different subsets of patients will likely respond to differently targeted therapies. Citation Format: Daniel Cook, Joseph R. Peterson, Patricia Carrigan, Tushar Pandey, John Cole, The SimBioSys Team. Profiling the metabolism of pancreatic adenocarcinoma using a systems medicine-based approach reveals insights into tumor biology, prognosis, and new therapeutic strategies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2715.

Abstract 5974: Multimodal molecular imaging detects early reoxygenation induced by hyaluronan depletion in pancreatic cancer model mouse

Abstract [Purpose] In pancreatic ductal adenocarcinoma (PDAC) which is characterized by an intense desmoplastic feature, the extracellular matrix (ECM) can significantly influence the tumor microenvironment (TME). Hyaluronan (HA), a major component of ECM, is associated with elevated tumor pressure, vascular collapse, and poor perfusion in TME, conferring hypoxia. HA expression is also correlated with poor prognosis in the patients with PDAC. PEGylated human hyaluronidase (PEGPH20) enzymatically depletes hyaluronan in tumors. The resultant improvement in vascular patency and blood perfusion is expected to increase the delivery of therapeutic molecules. The aim of this study was to investigate the change in physiologic and metabolic profile of the tumor in response to treatment with PEGPH20 using multi-modal imaging techniques. We also investigated the capability of PEGPH20 to enhance treatment effect of radiation. [Methods] Athymic nude mice were inoculated with BxPC3 (human pancreatic adenocarcinoma) tumor cells transduced with hyaluronan synthase 3 (HAS3) to the right tibial periosteum. BxPC3-HAS3 tumor treated with PEGPH20 or control buffer were scanned with Electron paramagnetic Resonance imaging (EPRI), dynamic contrast enhanced (DCE) MRI, ultra-small superparamagnetic iron oxide (USPIO) MRI, Photoacoustic imaging (PAI), and Hyperpolarized 13C-MRI using [1-13C] pyruvate to evaluate intratumor pO2, intratumor perfusion, blood volume, O2 saturation, and glycolysis, respectively. [Results] EPRI showed significantly increased pO2 in PEGPH20 treated group. DCE-MRI and USPIO-MRI showed improved perfusion/permeability and local blood volume, respectively after PEGPH20 treatment, accounting for the increase in tumor oxygenation. PAI provided the evidence of immediate changes in tumor oxygenation after treatment. Hyperpolarized 13C-MRI using [1-13C] pyruvate suggested the decreased glycolytic flux evaluated by lactate/pyruvate ratio after PEGPH20 treatment. Combination of radiotherapy and PEGPH20 synergistically delayed tumor progression and prolonged the survival. [Conclusions] This study examined the effect of PEGPH20 on TME in PDAC xenograft model by using non-invasive multimodal imaging techniques. In summary, the non-invasive imaging modalities were useful in evaluating the changes in hemodynamics and metabolism in TME induced by modulation of ECM such as PEGPH20 treatment. PEGPH20 enhanced treatment effect of radiation therapy. The results validated the utility of the imaging methods to non-invasively monitor the changes in TME and predicted the radiosensitizing effect of hyaluronan depletion. Citation Format: Yu Saida, Tomohiro Seki, Shun Kishimoto, Jeffrey R. Brender, Gadisetti VR. Chandramouli, Yasunori Otowa, Kota Yamashita, Kazutoshi Yamamoto, Nallathamby Devasahayam, Murali C. Krishna. Multimodal molecular imaging detects early reoxygenation induced by hyaluronan depletion in pancreatic cancer model mouse [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5974.