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Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant diseases because of its non-symptomatic tumorigenesis. We previous found heat shock factor 1 (HSF1) was critical for PDAC progression and the aim of this study was to clarified the mechanisms on early activation of HSF1 and its role in the pancreatic cancer tumorigenesis. Methods: The expression and location of HSF1 on human or mice pancreatic tissues were examined by immunohistochemically staining. We mainly used pancreatic acinar cell 3-dimensional (3D) culture and a spontaneous pancreatic precancerous lesion mouse model called LSL-KrasG12D/+; Pdx1-Cre (KC) (and pancreatitis models derived from KC mice) to explore the pro-tumorigenesis mechanisms of the HSF1 in vitro and in vivo. Bioinformatics and molecular experiments were used to explore the underlying mechanisms between HSF1 and epidermal growth factor receptor (EGFR). Results: In this study, we found that pharmacological inhibition of HSF1 slowed pancreatic cancer initiation and suppressed the pancreatitis-induced formation of pancreatic precancerous lesion. Next, bioinformatics analysis revealed the closely linked between HSF1 and EGFR pathway and we also confirmed their parallel activation in pancreatic precancerous lesions. Besides, the pharmacological inhibition of EGFR suppressed the initiation of pancreatic cancer and the activation of HSF1 in vivo. Indeed, we demonstrated that the EGFR activation that mediated pancreatic cancer tumorigenesis was partly HSF1-dependent in vitro. Conclusion: Hence, we concluded that the EGFR-HSF1 axis promoted the initiation of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Background: Diabetes is recognized to be a risk factor of pancreatic cancer, but the mechanism has not been fully elucidated. Sterol regulatory element binding protein 1 (SREBP1) is an important transcription factor involved in both lipid metabolism and tumor progression. However, the relationship between high glucose microenvironment, SREBP1 and pancreatic cancer remains to be explored. Methods: Clinical data and surgical specimens were collected. Pancreatic cancer cell lines BxPc-3 and MiaPaCa-2 were cultured in specified medium. Immunohistochemistry (IHC) and western blotting were performed to detect the expression of SREBP1. MTT and colony formation assays were applied to investigate cell proliferation. Immunofluorescence, mRFP-GFP adenoviral vector and transmission electron microscopy were performed to evaluate autophagy. We used streptozotocin (STZ) to establish a high glucose mouse model for the in vivo study. Results: We found that high blood glucose levels were associated with poor prognosis in pancreatic cancer patients. SREBP1 was overexpressed in both pancreatic cancer tissues and pancreatic cancer cell lines. High glucose microenvironment promoted tumor proliferation, suppressed apoptosis and inhibited autophagy level by enhancing SREBP1 expression. In addition, activation of autophagy accelerated SREBP1 expression and suppressed apoptosis. Moreover, high glucose promotes tumor growth in vivo by enhancing SREBP1 expression. Conclusion: Our results indicate that SREBP1-autophagy axis plays a crucial role in tumor progression induced by high glucose microenvironment. SREBP1 may represent a novel target for pancreatic cancer prevention and treatment. [ABSTRACT FROM AUTHOR]