BACKGROUND: Pancreatic cancer is a lethal malignancy prone to gemcitabine resistance. The single-strand selective monofunctional uracil DNA glycosylase (SMUG1), which is responsible for initiating base excision repair, has been reported to predict the outcomes of different cancer types. However, the function of SMUG1 in pancreatic cancer is still unclear. METHODS: Gene and protein expression of SMUG1 as well as survival outcomes were assessed by bioinformatic analysis and verified in a cohort from Fudan University Shanghai Cancer Center. Subsequently, the effect of SMUG1 on proliferation, cell cycle, and migration abilities of SMUG1 cells were detected in vitro . DNA damage repair, apoptosis, and gemcitabine resistance were also tested. RNA sequencing was performed to determine the differentially expressed genes and signaling pathways, followed by quantitative real-time polymerase chain reaction and Western blotting verification. The cancer-promoting effect of forkhead box Q1 (FOXQ1) and SMUG1 on the ubiquitylation of myelocytomatosis oncogene (c-Myc) was also evaluated. Finally, a xenograft model was established to verify the results. RESULTS: SMUG1 was highly expressed in pancreatic tumor tissues and cells, which also predicted a poor prognosis. Downregulation of SMUG1 inhibited the proliferation, G1 to S transition, migration, and DNA damage repair ability against gemcitabine in pancreatic cancer cells. SMUG1 exerted its function by binding with FOXQ1 to activate the Protein Kinase B (AKT)/p21 and p27 pathway. Moreover, SMUG1 also stabilized the c-Myc protein via AKT signaling in pancreatic cancer cells. CONCLUSIONS SMUG1 promotes proliferation, migration, gemcitabine resistance, and c-Myc protein stability in pancreatic cancer via protein kinase B signaling through binding with FOXQ1. Furthermore, SMUG1 may be a new potential prognostic and gemcitabine resistance predictor in pancreatic ductal adenocarcinoma.
Humans ; Pancreatic Neoplasms/pathology* ; Forkhead Transcription Factors/genetics* ; Signal Transduction/genetics* ; Animals ; Cell Line, Tumor ; Proto-Oncogene Proteins c-akt/metabolism* ; Cell Proliferation/physiology* ; Mice ; Uracil-DNA Glycosidase/genetics* ; Female ; Male ; Gemcitabine ; Mice, Nude ; Apoptosis/physiology* ; Deoxycytidine/analogs & derivatives* ; Cell Movement/genetics*

Objective The aim of this study was to investigate the effect of p38 on stem cell maintenance of pancreatic cancer. Methods Human pancreatic cancer cells PANC-1 were treated with different concentrations of 5-fluorouracil(5-FU)(0.5×IC₅₀, IC₅₀, and 2×IC₅₀) for 24 hours, and VX-702 (p38 phosphorylation inhibitor) was added, and the cells were inoculated in 6-well culture dishes with ultra-low adhesion to observe the changes of sphere tumors. The expression levels of cyclin-dependent kinase 2(CDK2), cyclin B1 and D1, Octamer-binding transcription factor 4(OCT4), SRY-box transcription factor 2(SOX2), Nanog and p38 were measured by Western blot. The mRNA expression levels of p38, OCT4, Nanog and SOX2 were tested by RT-PCR. Cell cycle, apoptosis, and the proportion of CD44⁺CD133⁺PANC-1 cells were evaluated by flow cytometry. Results The results showed that 5-FU inhibited the formation of tumor spheres in PANC-1 cells, increased CD44⁺CD133⁺cell fragments, down-regulated the expression of OCT4, Nanog and SOX2, and inhibited the stemness maintenance of PANC-1 tumor stem cells. Phosphorylation of PANC-1 cells was inhibited by a highly selective p38 MAPK inhibitor, VX-702(p38 mitogen-activated protein kinase inhibitor), which had the same effect as 5-FU treatment. When VX-702 combined with 5-FU was used to treat PANC-1 cells, the therapeutic effect was enhanced. Conclusion p38 inhibitors decreased PANC-1 cell activity and increased cell apoptosis. p38 inhibitors inhibit the stemness maintenance of pancreatic cancer stem cells.
Humans ; Phosphorylation/drug effects* ; Cell Line, Tumor ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors* ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Fluorouracil/pharmacology* ; Pancreatic Neoplasms/pathology* ; Apoptosis/drug effects* ; SOXB1 Transcription Factors/genetics* ; Octamer Transcription Factor-3/genetics*

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive lethal malignancy, characterized by late diagnosis, aggressive growth, and therapy resistance, leading to a poor overall prognosis. Emerging evidence shows that the peripheral nerve is an important non-tumor component in the tumor microenvironment that regulates tumor growth and immune escape. The crosstalk between the neuronal system and PDAC has become a hot research topic that may provide novel mechanisms underlying tumor progression and further uncover promising therapeutic targets. In this review, we highlight the mechanisms of perineural invasion and the role of various types of tumor innervation in the progression of PDAC, summarize the potential signaling pathways modulating the neuronal-cancer interaction, and discuss the current and future therapeutic possibilities for this condition.
Humans ; Carcinoma, Pancreatic Ductal/pathology* ; Pancreatic Neoplasms/therapy* ; Signal Transduction ; Peripheral Nerves/metabolism* ; Tumor Microenvironment

The characteristic genetic abnormality of neuroendocrine neoplasms (NENs), a heterogeneous group of tumors found in various organs, remains to be identified. Here, based on the analysis of the splicing variants of an oncogene Focal Adhesion Kinase (FAK) in The Cancer Genome Atlas datasets that contain 9193 patients of 33 cancer subtypes, we found that Box 6/Box 7-containing FAK variants (FAK^6/7) were observed in 7 (87.5%) of 8 pancreatic neuroendocrine carcinomas and 20 (11.76%) of 170 pancreatic ductal adenocarcinomas (PDACs). We tested FAK variants in 157 tumor samples collected from Chinese patients with pancreatic tumors, and found that FAK^6/7 was positive in 34 (75.6%) of 45 pancreatic NENs, 19 (47.5%) of 40 pancreatic solid pseudopapillary neoplasms, and 2 (2.9%) of 69 PDACs. We further tested FAK splicing variants in breast neuroendocrine carcinoma (BrNECs), and found that FAK^6/7 was positive in 14 (93.3%) of 15 BrNECs but 0 in 23 non-NEC breast cancers. We explored the underlying mechanisms and found that a splicing factor serine/arginine repetitive matrix protein 4 (SRRM4) was overexpressed in FAK^6/7-positive pancreatic tumors and breast tumors, which promoted the formation of FAK^6/7 in cells. These results suggested that FAK^6/7 could be a biomarker of NENs and represent a potential therapeutic target for these orphan diseases.
Female ; Humans ; Alternative Splicing ; Breast Neoplasms/metabolism* ; Carcinoma, Pancreatic Ductal/pathology* ; Focal Adhesion Protein-Tyrosine Kinases/therapeutic use* ; Nerve Tissue Proteins/genetics* ; Neuroendocrine Tumors/genetics* ; Oncogenes ; Pancreatic Neoplasms/metabolism*

Pancreatic cancer has an insidious onset and lacks effective treatment methods, which is one of the tumors with the worst prognosis, so it is urgent to explore new treatment directions. Metabolic reprogramming is one of the important hallmarks of tumors. Pancreatic cancer cells in the harsh tumor microenvironment have comprehensively increased cholesterol metabolism in order to maintain strong metabolic needs, and cancer associated fibroblasts also provide cancer cells with a large amount of lipids. Cholesterol metabolism reprogramming involves the changes in the synthesis, uptake, esterification and metabolites of cholesterol, which are closely related to the proliferation, invasion, metastasis, drug resistance, and immunosuppression of pancreatic cancer. Inhibition of cholesterol metabolism has obvious anti-tumor effect. In this paper, the important effects and complexity of cholesterol metabolism in pancreatic cancer were comprehensively reviewed from perspectives of risk factors for pancreatic cancer, energy interaction between tumor-related cells, key targets of cholesterol metabolism and its targeted drugs. Cholesterol metabolism has a strict regulation and feedback mechanism, and the effect of single-target drugs in clinical application is not clear. Therefore, multi-target therapy of cholesterol metabolism is a new direction for pancreatic cancer treatment.
Humans ; Pancreatic Neoplasms/pathology* ; Cholesterol/metabolism* ; Tumor Microenvironment

Objective: To explore the mechanism of Doublecortin-like kinase 1 (DCLK1) in promoting cell migration, invasion and proliferation in pancreatic cancer. Methods: The correlation between DCLK1 and Hippo pathway was analyzed using TCGA and GTEx databases and confirmed by fluorescence staining of pancreatic cancer tissue microarrays. At the cellular level, immunofluorescence staining of cell crawls and western blot assays were performed to clarify whether DCLK1 regulates yes associated protein1 (YAP1), a downstream effector of the Hippo pathway. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to analyze the expressions of YAP1 binding transcription factor TEA-DNA binding proteins (TEAD) and downstream malignant behavior-promoting molecules CYR61, EDN1, AREG, and CTGF. Transwell test of the DCLK1-overexpressing cells treated with the Hippo pathway inhibitor Verteporfin was used to examine whether the malignant behavior-promoting ability was blocked. Analysis of changes in the proliferation index of experimental cells used real-time label-free cells. Results: TCGA combined with GTEx data analysis showed that the expressions of DCLK1 and YAP1 molecules in pancreatic cancer tissues were significantly higher than those in adjacent tissues (P<0.05). Moreover, DCLK1was positively correlated with the expressions of many effectors in the Hippo pathway, including LATS1 (r=0.53, P<0.001), LATS2 (r=0.34, P<0.001), MOB1B (r=0.40, P<0.001). In addition, the tissue microarray of pancreatic cancer patients was stained with multicolor fluorescence, indicated that the high expression of DCLK1 in pancreatic cancer patients was accompanied by the up-regulated expression of YAP1. The expression of DCLK1 in pancreatic cancer cell lines was analyzed by the CCLE database. The results showed that the expression of DCLK1 in AsPC-1 and PANC-1 cells was low. Thus, we overexpressed DCLK1 in AsPC-1 and PANC-1 cell lines and found that DCLK1 overexpression in pancreatic cancer cell lines promoted YAP1 expression and accessible to the nucleus. In addition, DCLK1 up-regulated the expression of YAP1 binding transcription factor TEAD and increased the mRNA expression levels of downstream malignant behavior-promoting molecules. Finally, Verteporfin, an inhibitor of the Hippo pathway, could antagonize the cell's malignant behavior-promoting ability mediated by high expression of DCLK1. We found that the number of migrated cells with DCLK1 overexpressing AsPC-1 group was 68.33±7.09, which was significantly higher than 22.00±4.58 of DCLK1 overexpressing cells treated with Verteporfin (P<0.05). Similarly, the migration number of PANC-1 cells overexpressing DCLK1 was 65.66±8.73, which was significantly higher than 37.00±6.00 of the control group and 32.33±9.61 of Hippo pathway inhibitor-treated group (P<0.05). Meanwhile, the number of invasive cells in the DCLK1-overexpressed group was significantly higher than that in the DCLK1 wild-type group cells, while the Verteporfin-treated DCLK1-overexpressed cells showed a significant decrease. In addition, we monitored the cell proliferation index using the real-time cellular analysis (RTCA) assay, and the proliferation index of DCLK1-overexpressed AsPC-1 cells was 0.66±0.04, which was significantly higher than 0.38±0.01 of DCLK1 wild-type AsPC-1 cells (P<0.05) as well as 0.05±0.03 of DCLK1-overexpressed AsPC1 cells treated with Verteporfin (P<0.05). PANC-1 cells showed the same pattern, with a proliferation index of 0.77±0.04 for DCLK1-overexpressed PANC-1 cells, significantly higher than DCLK1-overexpressed PANC1 cells after Verteporfin treatment (0.14±0.05, P<0.05). Conclusion: The expression of DCLK1 is remarkably associated with the Hippo pathway, it promotes the migration, invasion, and proliferation of pancreatic cancer cells by activating the Hippo pathway.
Humans ; Doublecortin-Like Kinases ; Hippo Signaling Pathway ; Verteporfin/pharmacology* ; Cell Line, Tumor ; Protein Serine-Threonine Kinases/metabolism* ; Pancreatic Neoplasms/pathology* ; YAP-Signaling Proteins ; Transcription Factors/metabolism* ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Tumor Suppressor Proteins/genetics*

BACKGROUND: Cell competition is an important feature in pancreatic cancer (PC) progression, but the underlying mechanism remains elusive. This study aims to explore the role of exosomes derived from normal pancreatic ductal epithelial cells involved in PC progression. METHODS: PC cells and pancreatic stellate cells (PSCs) were treated with exosomes isolated from pancreatic ductal epithelial cells. Cell proliferation was assessed by CCK8 assays. Cell migration and invasion were assessed by Transwell assays. PC and matched adjacent non-tumor tissue specimens were obtained from 46 patients pathologically diagnosed with PC at Peking University First Hospital from 2013 to 2017. Tissue miR-485-3p and p21-activated kinase-1 (PAK1) expression was examined by real-time polymerase chain reaction (RT-PCR), and the relationship of the two was analyzed using Pearman's product-moment correlation. The clinical significance of miR-485-3p was analyzed using the Chi-square test, Wilcoxon rank-sum test, and Fisher exact probability, respectively. The binding of miR-485-3p to PAK1 5'-untranslated region (5'-UTR) was examined by luciferase assay. PC cells were xenografted into nude mice as a PC metastasis model. RESULTS: Exosomes from pancreatic ductal epithelial cells suppressed PC cell migration and invasion as well as the secretion and migration of PSCs. MiR-485-3p was enriched in the exosomes of pancreatic ductal epithelial cells but deficient in those of PC cells and PSCs, in accordance with the lower level in PSCs and PC cells than that in pancreatic ductal cells. And the mature miR-485-3p could be delivered into these cells by the exosomes secreted by normal pancreatic duct cells, to inhibit PC cell migration and invasion. Clinical data analysis showed that miR-485-3p was significantly decreased in PC tissues (P < 0.05) and was negatively associated with lymphovascular invasion (P = 0.044). As a direct target of miR-485-3p, PAK1 was found to exert an inhibitory effect on PC cells, and there was a significantly negative correlation between the expression levels of miR-485-3p and PAK1 (r = -0.6525, P < 0.0001) in PC tissues. Moreover, miR-485-3p could suppress PC metastasis in vivo by targeting p21-activated kinase-1. CONCLUSIONS Exosomal miR-485-3p delivered by normal pancreatic ductal epithelial cells into PC cells inhibits PC metastasis by directly targeting PAK1. The restoration of miR-485-3p by exosomes or some other vehicle might be a novel approach for PC treatment.
Animals ; Mice ; MicroRNAs/metabolism* ; Mice, Nude ; p21-Activated Kinases/metabolism* ; Cell Line, Tumor ; Pancreatic Neoplasms/genetics* ; Epithelial Cells/metabolism* ; Pancreatic Ducts/pathology* ; Cell Proliferation ; Cell Movement ; Gene Expression Regulation, Neoplastic

Objective: To investigate the clinicopathological characteristics of pancreatic lesions in children. Methods: The clinicopathological data of pancreatic lesions in children were analyzed including 42 cases of pancreatic tumors diagnosed from January 2000 to May 2021 in Guangzhou Women's and Children's Medical Center, Guangzhou, China. Histological and immunohistochemical assessments were performed . Related literature was reviewed. Results: The 42 pediatric patients with pancreatic lesions aged 1 day to 12 years (mean, 4.25 years). There were 23 males and 19 females. Clinical presentations included abdominal masses, abdominal pain, vomiting and persistent hypoglycemia after birth. Ultrasound and computerized tomography examination showed space-occupying pancreatic lesions in 31 cases, but no detectable pancreatic lesions in 11 cases. Histologically, among the 42 cases, 22 cases (52.4%) were neoplastic, including 18 cases of epithelial origin. Nine cases of pancreatoblastoma showed that the epithelial tumor cells were arranged in a trabecular pattern, with squamous nests. Six cases of solid-pseudopapillary tumors revealed hemorrhagic and necrotic cysts and monomorphic epithelioid cells arranged in solid sheets, nests or pseudopapillae. Two cases of neuroendocrine tumors showed tumor cells arranged in cords or nests; one case had a mitotic count of about 3/10 high power field, and a Ki-67 index of about 5%, which was consistent with G2 neuroendocrine tumor; the other case showed tumor cells with cytological atypia, brisk mitoses, about 25/10 HPF and a Ki-67 index of about 80%, consistent with small-cell type neuroendocrine carcinoma. The case of acinar cell carcinoma showed high cellularity, tumor cells in solid, cord-like or acinar-like arrangement with little stroma, and monotonous tumor cells with single distinct nucleolus. There were 4 cases of mesenchymal tumors, including 3 cases of Kaposi's hemangioendothelioma and 1 case of inflammatory myofibroblastic tumor. Among the 20 cases (47.6%) of non-neoplastic lesions, there were 11 cases of hyperinsulinism with ATP-sensitive potassium channel abnormality (HAPCA). Severn cases of diffuse type HAPCA in which the islets scattered between the pancreatic acinar tissue, enlarged, and prominent nuclei. Three cases of focal type HAPCA showed pancreatic islet hyperplasia in the form of nested nodules (0.6-1.5 cm). One case of atypical type HAPCA had extensive islet hyperplasia in pancreatic tissue, and scattered proliferation of nest-like nodules was noted. There were also 7 cases of pseudocyst and 2 cases of congenital cyst. Immunohistochemically, pancreatoblastomas were diffusely positive for CKpan, CK8/18, and β-catenin (nuclear staining of squamous nests only). Solid-pseudopapillary tumors expressed CD10, cyclin D1, CD99, vimentin, CD56, and β-catenin (nuclear staining). Neuroendocrine tumors were positive for CK, Syn, NSE, CgA, CD56, and β-catenin (membranous staining). The acinar cell carcinoma was positive for CK8/18, trypsin, and β-catenin (membranous staining). Conclusions: Pancreatic lesions in children have a wide range of histopathological types. HAPCA is the most common lesion of newborns. Pediatric pancreatic tumors are rare and mostly malignant. It is important to recognize them and make correct pathological diagnoses.
Carcinoma, Acinar Cell/pathology* ; Carcinoma, Squamous Cell ; Child ; Female ; Humans ; Hyperplasia ; Infant, Newborn ; Ki-67 Antigen ; Male ; Neuroendocrine Tumors ; Pancreatic Neoplasms/metabolism* ; beta Catenin/analysis*

Objective: To investigate the tumor immunity-related pathologic features and clinical significance in pancreatic ductal adenocarcinoma (PDAC). Methods: All pathologic materials and clinical information of 192 PDAC patients from the Cancer Hospital of the University of Chinese Academy of Sciences from January 2010 to December 2020 were collected. The onco-immune microenvironment associated morphologic features were evaluated, and MHC-Ⅰ, PD-L1, CD3, and CD8 expression were detected by immunohistochemistry (IHC). Then the correlation between the factors and their influence on prognosis was analyzed. Results: There were 163 cases of non-specific adenocarcinoma (163/192, 84.90%), 18 cases of adeno-squamous carcinoma (18/192, 9.37%), and 11 cases of other rare subtypes (11/192, 5.73%). Perineural invasion was observed in 110 cases (110/192, 57.29%) and vascular invasion in 86 cases (86/192, 44.79%). There were 84 cases (84/182, 46.15%) with severe chronic inflammation. Tumor infiltrating immune cell numbers (TII-N) were increased in 52 cases (52/192, 27.08%). Lymphocytes and plasma cells were the main infiltrating immune cells in 60 cases (60/192, 31.25%), whereas in 34 cases (34/192, 17.71%) the tumors were mainly infiltrated by granulocytes, and 98 cases (98/192, 51.04%) showed mixed infiltration. CD3⁺T cells were deficient in 124 cases (124/192, 66.31%). CD8⁺T cells were deficient in 152 cases (152/192, 79.58%). MHC-Ⅰ expression was down-regulated in 156 cases (156/192, 81.25%), and PD-L1 was positive (CPS≥1) in 46 cases (46/192, 23.96%). Statistical analysis showed that TII-N was negatively correlated with vascular invasion (P=0.035), perineural invasion (P=0.002), stage (P=0.004) and long-term alcohol consumption (P=0.039). The type of immune cells correlated positively with chronic pancreatic inflammation (P=0.002), and negatively with tumor differentiation (P=0.024). CD8⁺T cells were positively correlated with CD3⁺T cells (P=0.032), MHC-Ⅰ expression (P<0.001) and PD-L1 expression (P=0.001), and negatively correlated with long-term smoking (P=0.016). Univariate analysis showed that histological nonspecific type (P=0.013) and TII-N (P<0.001) were the factors for good prognosis. Vascular invasion (P=0.032), perineural invasion (P=0.001), high stage (P=0.003) and long-term alcohol consumption (P=0.004) were adverse prognostic factors. COX multivariate risk analysis found that TII-N was an independent favorable factor for PDAC, while perineural invasion was an independent adverse risk factor. Conclusions: TII-N is an independent superior prognostic factor for PDAC, and significantly correlated with many factors; chronic alcohol consumption and smoking may inhibit onco-immunity in PDAC patients.
Adenocarcinoma/pathology* ; B7-H1 Antigen/metabolism* ; Biomarkers, Tumor/metabolism* ; Carcinoma, Pancreatic Ductal/pathology* ; Humans ; Inflammation/pathology* ; Lymphocytes, Tumor-Infiltrating/metabolism* ; Pancreatic Neoplasms/pathology* ; Prognosis ; Tumor Microenvironment

Polyphyllin D is a steroid saponin monomer in Polyphyllin, with antibacterial, analgesic, sedative, anti-tumor and other pharmacological effects, but is rarely reported in pancreatic cancer. This study detected apoptosis-relevant indicators, in order to explore the effect of polyphyllin D on the proliferation and apoptosis of human pancreatic cancer Panc-1 cells and relevant mechanisms of action. After pancreatic cancer Panc-1 cells were treated with polyphyllin D(0, 1, 2, 3, 4, 5 μg·μL~(-1)) for 24, 48 and 72 hours, CCK-8 method was used to detect the effect of polyphyllin D on the proliferation of pancreatic cancer Panc-1 cells. Flow cytometry was used to detect cell cycle and changes in mitochondrial membrane potential(MMP). The apoptosis was detected by Annexin V-FITC/PI staining, and Western blot was used to detect the protein expressions of cytochrome C(Cyto C), Bax, Bcl-2, cleaved caspase-3 and cleaved caspase-9. The results indicated that compared with the control group, polyphyllin D could inhibit the proliferative activity of Panc-1 cells in a time and concentration-dependent manner. Flow cytometry results showed that polyphyllin D could block the cells in S and G_2/M phase in a concentration manner, the MMP of the cells was significantly reduced, and the apoptosis rate increased with the concentration of polyphyllin D. Western blot results showed that polyphyllin D could concentration-dependently up-regulate the protein expression levels of Bax, Cyto C, cleaved caspase-3 and cleaved caspase-9, and down-regulate the protein expression level of Bcl-2. The above findings suggested that polyphyllin D could effectively inhibit the proliferation of Panc-1 cells, and its mechanism may be related to the blocking of cell growth cycle and the apoptosis induced by mitochondrial pathway.
Antineoplastic Agents, Phytogenic/pharmacology* ; Apoptosis ; Caspase 3/metabolism* ; Caspase 9/metabolism* ; Cell Line, Tumor ; Cell Proliferation ; Diosgenin/pharmacology* ; Humans ; Pancreatic Neoplasms/pathology* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Saponins/pharmacology* ; bcl-2-Associated X Protein/metabolism*