Docosahexaenoic Acid Inhibits Cell Proliferation through a Suppression of c-Myc Protein in Pancreatic Ductal Adenocarcinoma Cells.
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ABSTRACT:
SUBMITTER: Syu JN
PROVIDER: S-EPMC8614909 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The treatment of cancer cells obtained by blocking cellular metabolism has received a lot of attention recently. Previous studies have demonstrated that Kras mutation-mediated abnormal glucose metabolism would lead to an aberrant cell proliferation in human pancreatic ductal adenocarcinoma (PDAC) cells. Previous literature has suggested that consumption of fish oil is associated with lower risk of pancreatic cancer. In this study, we investigated the anti-cancer effects of docosahexaenoic acid (DHA) in human PDAC cells in vitro and in vivo. Omega-3 polyunsaturated fatty acids (PUFAs) such as DHA and eicosapentaenoic acid (EPA) significantly inhibited the proliferation of human PDAC cells. The actions of DHA were evaluated through an induction of cell cycle arrest at G1 phase and noticed a decreased expression of cyclin A, cyclin E and cyclin B proteins in HPAF-II cells. Moreover, it was found that co-treatment of DHA and gemcitabine (GEM) effectively induced oxidative stress and cell death in HPAF-II cells. Interestingly, DHA leads to an increased oxidative glutathione /reduced glutathione (GSSG/GSH) ratio and induced cell apoptosis in HPAF-II cells. The findings in the study showed that supplementation of GSH or N-Acetyl Cysteine (NAC) could reverse DHA-mediated cell death in HPAF-II cells. Additionally, DHA significantly increased cellular level of cysteine, cellular NADP/NADPH ratio and the expression of cystathionase (CTH) and SLCA11/xCT antiporter proteins in HPAF-II cells. The action of DHA was, in part, associated with the inactivation of STAT3 cascade in HPAF-II cells. Treatment with xCT inhibitors, such as erastin or sulfasalazine (SSZ), inhibited the cell survival ability in DHA-treated HPAF-II cells. DHA also inhibited nucleotide synthesis in HPAF-II cells. It was demonstrated in a mouse-xenograft model that consumption of fish oil significantly inhibited the growth of pancreatic adenocarcinoma and decreased cellular nucleotide level in tumor tissues. Furthermore, fish oil consumption induced an increment of GSSG/GSH ratio, an upregulation of xCT and CTH proteins in tumor tissues. In conclusion, DHA significantly inhibited survival of PDAC cells both in vitro and in vivo through its recently identified novel mode of action, including an increment in the ratio of GSSG/GSH and NADP/NADPH respectively, and promoting reduction in the levels of nucleotide synthesis.
| S-EPMC7605869 | biostudies-literature
Project description:Chromosome 16 open reading frame 74 (C16orf74) is highly expressed in pancreatic ductal adenocarcinoma (PDAC) and is involved in cancer cell proliferation and invasion through binding to calcineurin (CN). Therefore, C16orf74 is a good target for the development of a PDAC treatment. A cell-permeable dominant-negative (DN) peptide that can inhibit the C16orf74/CN interaction was designed to examine whether this peptide can inhibit PDAC cell proliferation in vitro and in vivo.TheDN-C16orf74 peptide, which corresponds to the portion of C16orf74 that interacts with CN, was synthesized, and we assessed its anti-tumor activity in proliferation assays with human PDAC cells and the underlying molecular signaling pathway. Using an orthotopic xenograft model of PDAC, we treated mice intraperitoneally with phosphate-buffered saline (PBS), control peptide, or DN-C16orf74 and analyzed the tumor-suppressive effects.DN-C16orf74 inhibited the binding of C16orf74 to CN in an immunoprecipitation assay. DN-C16orf74 suppressed PDAC cell proliferation, and the level of suppression depended on the expression levels of C16orf74 in vitro. DN-C16orf74 also exhibited anti-tumor effects in orthotopic xenograft model. Furthermore, the tumor-suppressive effect was associated with inhibition of the phosphorylation of Akt and mTOR.The cell-permeable peptide DN-C16orf74 has a strong anti-tumor effect against PDAC in vitro and in vivo.
| S-EPMC5768354 | biostudies-literature
Project description:Synaptophysin-like 1 (SYPL1) is a neuroendocrine-related protein. The role of SYPL1 in pancreatic ductal adenocarcinoma (PDAC) and the underlying molecular mechanism remain unclarified. Here, after analyzing five datasets (GSE15471, GSE16515, GSE28735, TCGA, and PACA-AU) and 78 PDAC patients from Sun Yat-sen University Cancer Center, we demonstrated that SYPL1 was upregulated in PDAC and that a high level of SYPL1 indicated poor prognosis. Bioinformatics analysis implied that SYPL1 was related to cell proliferation and cell death. To validate these findings, gain-of-function and loss-of-function experiments were carried out, and we found that SYPL1 promoted cell proliferation in vitro and in vivo and that it protected cells from apoptosis. Mechanistic studies revealed that sustained extracellular-regulated protein kinase (ERK) activation was responsible for the cell death resulting from knockdown of SYPL1. In addition, bioinformatics analysis showed that the expression of SYPL1 positively correlated with antioxidant activity. Reactive oxygen species (ROS) were upregulated in cells with SYPL1 knockdown and vice versa. Upregulated ROS led to ERK activation and cell death. These results suggest that SYPL1 plays a vital role in PDAC and promotes cancer cell survival by suppressing ROS-induced ERK activation.
| S-EPMC7522464 | biostudies-literature
Project description:BackgroundPancreatic cancer is a malignant tumor of the digestive tract, which is difficult to diagnose and treat due to bad early diagnosis. We aimed to explore the role of kinesin superfamily 4A (KIF4A) in pancreatic ductal adenocarcinoma (PDAC).MethodsWe first used the bioinformatic website to screen the data of pancreatic cancer in TCGA, and KIF4A protein was detected among the 86 specimens of patients in our hospital combined with clinic-pathological characteristics and survival analysis. KIF4A loss-expression cell lines were established by RNA interference (RNAi). In addition, we performed in vitro cell assays to detect the changes in cell proliferation, migration, and invasion. The proteins involved in the proliferation and metastasis of cancer cells were also detected by western blot. The above results could be proved in vivo. Further, the correlation between KIF4A and CDC5L was analyzed by TCGA and IHC data.ResultsWe first found a high expression of KIF4A in pancreatic cancer, suggesting a role of KIF4A in the development of pancreatic cancer. KIF4A was found to be differentially expressed (P < 0.05) among the 86 specimens of patients in our hospital and was significantly associated with PDAC TNM stages and tumor size. High KIF4A expression also significantly worsened overall survival (OS) and disease-free survival rate (DFS) (P < 0.05, respectively). In addition, cell proliferation, migration, and invasion were inhibited by the KIF4A-shRNA group compared with the control (P < 0.05, respectively). In the end, knockdown of KIF4A could inhibit tumor development and metastasis in vivo. Further, the positive correlation between KIF4A and CDC5L existed, and KIF4A might promote pancreatic cancer proliferation by affecting CDC5L expression.ConclusionIn conclusion, the high expression level of KIF4A in PDAC was closely related to poor clinical and pathological status, lymphatic metastasis, and vascular invasion. KIF4A might be involved in promoting the development of PDAC in vitro and in vivo, which might be a new therapeutic target of PDAC.
| S-EPMC8601854 | biostudies-literature
Project description:BackgroundUbiquitin-like protein 4A (UBL4A) plays a significant role in protein metabolism and the maintenance of cellular homeostasis. In cancer, UBL4A represses tumorigenesis and is involved in various signaling pathways. Pancreatic ductal adenocarcinoma (PDAC) is still a major cause of cancer-related death and the underlying molecular mechanism of UBL4A and PDAC remains unknown.MethodsFirst, the prognostic role of UBL4A and its expression in human PDAC patients and in pancreatic cancer cell lines were detected by survival analysis and qRT-PCR, western blotting, and immunohistochemistry. Next, the effects of UBL4A on proliferation and metastasis in pancreatic cancer were evaluated by functional assays in vitro and in vivo. In addition, chloroquine was introduced to determine the role of autophagy in UBL4A-related tumor proliferation and metastasis. Ultimately, coimmunoprecipitation was used to confirm the interaction between UBL4A and lysosome associated membrane protein-1 (LAMP1), and western blotting was performed to explore the UBL4A mechanism.ResultsWe found that UBL4A was decreased in PDAC and that high levels of UBL4A correlated with a favorable prognosis. We observed that UBL4A inhibited tumor proliferation and metastasis through suppression of autophagy, a critical intracellular catabolic process that reportedly protects cells from nutrient starvation and other stress conditions. UBL4A caused impaired autophagic degradation in vitro, a crucial process in autophagy, by disturbing the function of lysosomes and contributing to autophagosome accumulation. We found a positive correlation between UBL4A and LAMP1. Furthermore, UBL4A caused lysosomal dysfunction by directly interacting with LAMP1, and LAMP1 overexpression reversed the antitumor effects of UBL4A in pancreatic cancer. In addition, we demonstrated that UBL4A suppressed tumor growth and metastasis in a pancreatic orthotopic tumor model.ConclusionsThese findings suggest that UBL4A exerts an antitumor effect on autophagy-related proliferation and metastasis in PDAC by directly targeting LAMP1. Herein, we describe a novel mechanism of UBL4A that suppresses the progression of pancreatic cancer. UBL4A might be a promising target for the treatment and prognostication of PDAC.
| S-EPMC6617940 | biostudies-literature
Project description:Pancreatic ductal adenocarcinoma (PDAC) is associated with several genetic syndromes. However, the molecular mechanism underlying PDAC progression is still unknown. In this study, we showed that Laminin Subunit Beta 3 (LAMB3) was aberrantly overexpressed in PDAC and was closely associated with the overall survival rate of patients with PDAC. Functional studies demonstrated that LAMB3 played important roles in cell proliferation, the cell cycle, and invasion capacity. Using bioinformatics analysis, we determined that miR-24-3p was an upstream miRNA of LAMB3, and further experiments verified that miR-24-3p regulated LAMB3 expression in PDAC cells. A dual-luciferase reporter system demonstrated that miR-24-3p directly targeted the LAMB3 3'UTR, and FISH assay confirmed that miR-24-3p and LAMB3 mRNA mostly resided in cytoplasm, accounting for their post-translational regulation. Rescue assay demonstrated that miR-24-3p exerted its anti-cancer role by suppressing LAMB3 expression. Finally, by using a subcutaneous xenotransplanted tumor model, we demonstrated that miR-24-3p overexpression inhibited the proliferation of PDAC by suppressing LAMB3 expression in vivo. Collectively, our results provide evidence that the miR-24-3p/LAMB3 axis plays a vital role in the progression of PDAC and indicate that the miR-24-3p/LAMB3 axis may represent a novel therapeutic target for PDAC.
| S-EPMC6985431 | biostudies-literature
Project description:Long non-coding RNAs (lncRNAs) play crucial roles in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC). Previously, we found that melittin treatment suppressed PDAC tumor growth. However, it is unclear whether lncRNAs have any role in the melittin-induced suppression of PDAC. In this study, we used microarray data to identify 844 lncRNAs that were significantly differentially expressed in response to melittin treatment. Of these lncRNAs, we focused on the lncRNA NONHSAT105177, which had about a 22-fold increase in expression with melittin treatment. We found that melittin treatment increased NONHSAT105177 expression in PDAC cell lines but not in normal pancreatic ductal epithelial cell line. NONHSAT105177 expression was significantly lower in PDAC cancer tissues than in adjacent noncancerous tissues. Additionally, overexpression of NONHSAT105177 inhibited PDAC cell proliferation, migration, and the epithelial-mesenchymal transition (EMT), both in vitro and in vivo. Consistent with the mechanism of action of melittin, NONHSAT105177 significantly downregulated cholesterol pathway genes, including Clusterin (CLU). Moreover, we found that NONHSAT105177 trafficking was mediated by exosomes. The combined findings of our current and previous studies suggest that NONHSAT105177 mediated the melittin-induced inhibition of PDAC cell growth and metastasis, which indicated a potential target for developing new strategies.
| S-EPMC6148000 | biostudies-literature
Project description:Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, and it is unclear whether its stromal infiltrate contributes to its aggressiveness. Here, we demonstrate that Dickkopf-3 (DKK3) is produced by pancreatic stellate cells and is present in most human PDAC. DKK3 stimulates PDAC growth, metastasis, and resistance to chemotherapy with both paracrine and autocrine mechanisms through NF-?B activation. Genetic ablation of DKK3 in an autochthonous model of PDAC inhibited tumor growth, induced a peritumoral infiltration of CD8+ T cells, and more than doubled survival. Treatment with a DKK3-blocking monoclonal antibody inhibited PDAC progression and chemoresistance and prolonged survival. The combination of DKK3 inhibition with immune checkpoint inhibition was more effective in reducing tumor growth than either treatment alone and resulted in a durable improvement in survival, suggesting that DKK3 neutralization may be effective as a single targeted agent or in combination with chemotherapy or immunotherapy for PDAC.
| S-EPMC6752716 | biostudies-literature
Project description:Background:Pancreatic ductal adenocarcinoma (PDAC) is a lethal human malignancy, and previous researches support the contribution of microRNA (miRNA) to cancer progression. MiR-122-5p is reported to participate in the regulation of various cancers, while the function of miR-122-5p in PDAC remains unclear. In this study, we investigated the precise mechanism of miR-122-5p involved in PDAC pathogenesis. Methods:The expression levels of miR-122-5p were detected in human PDAC tissues and cell lines by miRNA RT-PCR. The effects of miR-122-5p on cell proliferation were explored by MTT assays, colony formation assays and flow cytometry assays. The ability of migration and invasion was determined by transwell assays. Dual Luciferase reporter assay was performed to validate the direct interaction between miR-122-5p and its target gene. The related molecules of cell cycle, apoptosis and epithelial-mesenchymal transition (EMT) were examined with qRT-PCR and western blot. In addition, xenograft mouse models were applied to explore the effects of miR-122-5p in vivo. Results:MiR-122-5p was underexpressed, while CCNG1 was highly expressed in PDAC tissues and cells. MiR-122-5p was negatively correlated with TNM stage, tumor size and lymph node metastasis in PDAC patients. Overexpression of miR-122-5p suppressed the proliferation, migration and invasion in vitro and inhibited tumorigenesis in vivo. Furthermore, CCNG1 was a direct target of miR-122-5p. Upregulated CCNG1 could partially reverse the effects caused by miR-122-5p. Moreover, miR-122-5p inhibited EMT through downregulation of CCNG1. Conclusion:Overexpression of miR-122-5p could inhibit cell proliferation, migration, invasion, and EMT by downregulating CCNG1 in PDAC, suggesting a potential therapeutic target for PDAC.
| S-EPMC7106816 | biostudies-literature
Project description:BACKGROUND:MicroRNAs can be used in the prognosis of malignancies; however, their regulatory mechanisms are unknown, especially in pancreatic ductal adenocarcinoma (PDAC). METHODS:In 120 PDAC specimens, miRNA levels were assessed by quantitative real time polymerase chain reaction (qRT-PCR). Then, the role of miR-29b-2-5p in cell proliferation was evaluated both in vitro (Trypan blue staining and cell cycle analysis in the two PDAC cell lines SW1990 and Capan-2) and in vivo using a xenograft mouse model. Next, bioinformatics methods, a luciferase reporter assay, Western blot, and immunohistochemistry (IHC) were applied to assess the biological effects of Cbl-b inhibition by miR-29b-2-5p. Moreover, the relationship between Cbl-b and p53 was evaluated by immunoprecipitation (IP), Western blot, and immunofluorescence. RESULTS:From the 120 PDAC patients who underwent surgical resection, ten patients with longest survival and ten with shortest survival were selected. We found that high miR-29b-2-5p expression was associated with good prognosis (p?=?0.02). The validation cohort confirmed miR-29b-2-5p as an independent prognostic factor in PDAC (n?=?100, 95% CI?=?0.305-0.756, p?=?0.002). Furthermore, miR-29b-2-5p inhibited cell proliferation, induced cell cycle arrest, and promoted apoptosis both in vivo and in vitro. Interestingly, miR-29b-2-5p directly bound the Cbl-b gene, down-regulating its expression and reducing Cbl-b-mediated degradation of p53. Meanwhile, miR-29b-2-5p expression was negatively correlated with Cbl-b in PDAC tissues (r?=?-?0.33, p?=?0.001). CONCLUSIONS:Taken together, these findings indicated that miR-29b-2-5p improves prognosis in PDAC by targeting Cbl-b to promote p53 expression, and would constitute an important prognostic factor in PDAC.
| S-EPMC6019739 | biostudies-literature