Triptolide targets super-enhancer networks in pancreatic cancer cells and cancer-associated fibroblasts

Abstract The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) is highly heterogeneous, fibrotic, and hypovascular, marked by extensive desmoplasia and maintained by the tumor cells, cancer-associated fibroblasts (CAFs) and other stromal cells. There is an urgent need to identify and develop treatment strategies that not only target the tumor cells but can also modulate the stromal cells. A growing number of studies implicate the role of regulatory DNA elements called super-enhancers (SE) in maintaining cell-type-specific gene expression networks in both normal and cancer cells. Using chromatin activation marks, we first mapped SE networks in pancreatic CAFs and epithelial tumor cells and found them to have distinct SE profiles. Next, we explored the role of triptolide (TPL), a natural compound with antitumor activity, in the context of modulating cell-type-specific SE signatures in PDAC. We found that TPL, cytotoxic to both pancreatic tumor cells and CAFs, disrupted SEs in a manner that resulted in the downregulation of SE-associated genes (e.g., BRD4, MYC, RNA Pol II, and Collagen 1) in both cell types at mRNA and protein levels. Our observations suggest that TPL acts as a SE interactive agent and may elicit its antitumor activity through SE disruption to re-program cellular cross talk and signaling in PDAC. Based on our findings, epigenetic reprogramming of transcriptional regulation using SE modulating compounds such as TPL may provide means for effective treatment options for pancreatic cancer patients.

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Growth Hormone Receptor Inhibition Sensitizes Human Pancreatic Cancer to Chemotherapy Treatments

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.2086 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A1019-A1020

Author(s):

Reetobrata Basu ◽

John Joseph Kopchick ◽

Silvana Duran Ortiz ◽

Yanrong Qian ◽

Prateek Kulkarni

Keyword(s):

Pancreatic Cancer ◽

Growth Hormone ◽

Cancer Cells ◽

Tumor Cells ◽

Hormone Receptor ◽

Growth Hormone Receptor ◽

Human Pancreatic Cancer ◽

Drug Efflux ◽

Pancreatic Cancer Cells

Abstract Human growth hormone (GH) and its cognate growth hormone receptor (GHR) have been established to have a distinct role in promoting the progression of several types of human cancers. We had earlier described a newfound role of the GH-GHR axis in driving chemoresistance in melanoma by upregulating drug efflux by ABC multidrug transporter expression and a phenotype switch by induction of epithelial-to-mesenchymal transition (EMT). Here we present an in-depth analysis of this role of GH-GHR in the highly therapy resistant human pancreatic cancer which has a 5-year survival rate of only 10% in 2020. Using human and mouse pancreatic cancer cells and RNA and protein expression analyses by RT-qPCR, ELISA, and western-blot, we identified that (i) GH upregulates specific ABC-transporter expressions in a drug-context specific manner, (ii) GH upregulates EMT transcription factors, (iii) GH activates specific oncogenic signaling pathways, and (iii) GH action increases cytochrome P450 members involved in hepatic drug metabolism. The GH antagonist, Pegvisomant, significantly inhibited these effects. Additionally, we confirmed the effects of these molecular changes by specific assays. For example, GH increases basement membrane invasion, viability of circulating tumor cells, and drug efflux; while inhibition of GHR by pegvisomant in pancreatic cancer cells reversed this aggressive tumor phenotype and sensitized the tumor cells to chemotherapy. Cell viability assays confirmed a decreased IC50 of gemcitabine, doxorubicin, and erlotinib in pancreatic cancer cells treated with pegvisomant and an increase in IC50 cells treated with GH. We further verified our results using in silico analyses of TCGA datasets for pancreatic cancer - which provided robust confirmation of our experimental findings. Presently we are validating our observation in nude mice with human pancreatic cancer cell xenografts. In conclusion, our in vitro results confirm that GHR antagonism can drastically sensitize human pancreatic cancer cells by blocking mechanisms of drug resistance, thus providing a valuable window for improved efficacy of available chemo- and targeted therapy.

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Imaging the Role of Multinucleate Pancreatic Cancer Cells and Cancer-Associated Fibroblasts in Peritoneal Metastasis in Mouse Models

Anticancer Research ◽

10.21873/anticanres.11711 ◽

2017 ◽

Vol 37 (7) ◽

Keyword(s):

Pancreatic Cancer ◽

Cancer Cells ◽

Mouse Models ◽

Peritoneal Metastasis ◽

Cancer Associated Fibroblasts ◽

Pancreatic Cancer Cells

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Patterns and Relevance of Langerhans Islet Invasion in Pancreatic Cancer

Cancers ◽

10.3390/cancers13020249 ◽

2021 ◽

Vol 13 (2) ◽

pp. 249

Author(s):

Ruediger Goess ◽

Ayse Ceren Mutgan ◽

Umut Çalışan ◽

Yusuf Ceyhun Erdoğan ◽

Lei Ren ◽

...

Keyword(s):

Diabetes Mellitus ◽

Pancreatic Cancer ◽

Cancer Cells ◽

Tumor Cells ◽

Islet Cells ◽

Human Pancreatic Cancer ◽

Type I ◽

Type Iv ◽

Pancreatic Cancer Cells

Background: Pancreatic cancer‐associated diabetes mellitus (PC‐DM) is present in most patients with pancreatic cancer, but its pathogenesis remains poorly understood. Therefore, we aimed to characterize tumor infiltration in Langerhans islets in pancreatic cancer and determine its clinical relevance. Methods: Langerhans islet invasion was systematically analyzed in 68 patientswith pancreatic ductal adenocarcinoma (PDAC) using histopathological examination and 3D in vitro migration assays were performed to assess chemoattraction of pancreatic cancer cells to isletcells. Results: Langerhans islet invasion was present in all patients. We found four different patterns of islet invasion: (Type I) peri‐insular invasion with tumor cells directly touching the boundary, but not penetrating the islet; (Type II) endo‐insular invasion with tumor cells inside the round islet; (Type III) distorted islet structure with complete loss of the round islet morphology; and (Type IV)adjacent cancer and islet cells with solitary islet cells encountered adjacent to cancer cells. Pancreatic cancer cells did not exhibit any chemoattraction to islet cells in 3D assays in vitro. Further, there was no clinical correlation of islet invasion using the novel Islet Invasion Severity Score (IISS), which includes all invasion patterns with the occurrence of diabetes mellitus. However, Type IV islet invasion was related to worsened overall survival in our cohort. Conclusions: We systematically analyzed, for the first time, islet invasion in human pancreatic cancer. Four different main patterns of islet invasion were identified. Diabetes mellitus was not related to islet invasion. However, moreresearch on this prevailing feature of pancreatic cancer is needed to better understand underlying principles.

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