scholarly journals Roles of autophagy and metabolism in pancreatic cancer cell adaptation to environmental challenges

2017 ◽  
Vol 313 (5) ◽  
pp. G524-G536 ◽  
Author(s):  
Sandrina Maertin ◽  
Jason M. Elperin ◽  
Ethan Lotshaw ◽  
Matthias Sendler ◽  
Steven D. Speakman ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) displays extensive and poorly vascularized desmoplastic stromal reaction, and therefore, pancreatic cancer (PaCa) cells are confronted with nutrient deprivation and hypoxia. Here, we investigate the roles of autophagy and metabolism in PaCa cell adaptation to environmental stresses, amino acid (AA) depletion, and hypoxia. It is known that in healthy cells, basal autophagy is at a low level, but it is greatly activated by environmental stresses. By contrast, we find that in PaCa cells, basal autophagic activity is relatively high, but AA depletion and hypoxia activate autophagy only weakly or not at all, due to their failure to inhibit mechanistic target of rapamycin. Basal, but not stress-induced, autophagy is necessary for PaCa cell proliferation, and AA supply is even more critical to maintain PaCa cell growth. To gain insight into the underlying mechanisms, we analyzed the effects of autophagy inhibition and AA depletion on PaCa cell metabolism. PaCa cells display mixed oxidative/glycolytic metabolism, with oxidative phosphorylation (OXPHOS) predominant. Both autophagy inhibition and AA depletion dramatically decreased OXPHOS; furthermore, pharmacologic inhibitors of OXPHOS suppressed PaCa cell proliferation. The data indicate that the maintenance of OXPHOS is a key mechanism through which autophagy and AA supply support PaCa cell growth. We find that the expression of oncogenic activation mutation in GTPase Kras markedly promotes basal autophagy and stimulates OXPHOS through an autophagy-dependent mechanism. The results suggest that approaches aimed to suppress OXPHOS, particularly through limiting AA supply, could be beneficial in treating PDAC. NEW & NOTEWORTHY Cancer cells in the highly desmoplastic pancreatic ductal adenocarcinoma confront nutrient [i.e., amino acids (AA)] deprivation and hypoxia, but how pancreatic cancer (PaCa) cells adapt to these conditions is poorly understood. This study provides evidence that the maintenance of mitochondrial function, in particular, oxidative phosphorylation (OXPHOS), is a key mechanism that supports PaCa cell growth, both in normal conditions and under the environmental stresses. OXPHOS in PaCa cells critically depends on autophagy and AA supply. Furthermore, the oncogenic activation mutation in GTPase Kras upregulates OXPHOS through an autophagy-dependent mechanism.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jing Chen ◽  
Cui-Cui Zhao ◽  
Fei-Ran Chen ◽  
Guo-Wei Feng ◽  
Fei Luo ◽  
...  

Background. Pancreatic 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). Methods. We 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. Results. We 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. Conclusion. In 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.


2020 ◽  
Vol 13 ◽  
Author(s):  
Ahmad Sada Al hanjori ◽  
Walhan Alshaer ◽  
Bayan Anati ◽  
Suha Wehaibi ◽  
Malek Zihlif

Background: Earlier diagnosis and advances in treatment strategies have increased the average survival of cancer patients over the last decades. Despite the increased number of new anti-neoplastic agents, there has been no adequate therapy for intricate malignancies such as pancreatic cancer. Cancer metabolism is the main building block standing behind cancer promotion and progression even in the presence of a harsh environment. Targeting metabolic pathways, such as glycolysis and pentose phosphate pathway, is regarded as a promising new strategy for cancer treatment. Objective: The current study is to investigate the effect of knocking-down pancreatic cancer glycolytic and pentose phosphate pathway's regulators (HIF-1α, ARNT, PFKFB4, and RBKS), on cell’s viability and resistance to gemcitabine and doxorubicin, using small interference RNA. Methodology: The human pancreatic ductal adenocarcinoma cell line, Panc-1, was used to study the anti-proliferative activity of targeting HIF-1α, ARNT, PFKFB4, and RBKS mRNAs by transfection with small interference RNAs, each one alone and in combination. The transfected cells were also treated with doxorubicin and gemcitabine to study the relationship between the concerned genes and the resistance of Panc-1 cells to these drugs. The effect on cell proliferation was determined using a colorimetric assay and Inhibitory Concentration (IC50) calculation. A cross-talk study was done to investigate the silencing effect of one of the above genes on the expression of others using Real Time-Polymerase Chain Reaction. Results: In vitro transfection with small interference-RNAs, siHIF-1α, siPFKFB4, and siARNT decreased tumor cell proliferation with a maximum effect shown with siPFKFB4; but there was no anti-proliferative effect with RBKS silencing. suppression of transcription of HIF-1α, ARNT, PFKFB4, and RBKS sensitize pancreatic cancer cells, Panc-1, to doxorubicin and gemcitabine. Conclusion: This study demonstrated the major tumor promoting and progressive effects of PFKFB4, while HIF-1α and ARNT had modulator effects in pancreatic cancer cells (Panc-1). RBKS had a chemo-resistant role justifying its enhanced expression in Panc-1 cells, but not a proliferative one. Silencing of all genes of interest decreased doxorubicin and gemcitabine's resistance and improved the antitumor effect of doxorubicin and gemcitabine in the pancreatic cancer cell line, Panc-1.


2020 ◽  
Author(s):  
Brenna A. Rheinheimer ◽  
Alex Cardenas ◽  
Luis Camacho ◽  
Evan S. Ong ◽  
Tun Jie ◽  
...  

AbstractBackgroundDeregulated phosphorylation of sphingosine by the sphingosine kinases and signaling through the EDG family of receptors enhances growth and survival in many cell types. Therefore, we sought to elucidate the effect of alterations in the ceramide/sphingosine/S1P rheostat on driving human pancreatic ductal adenocarcinoma towards a malignant phenotype.MethodsPancreatic cancer cell lines were treated with exogenous S1P, FTY720, and siRNA to Sphk1. Migration was evaluated by wound healing assays, cell growth by MTT assays, and invasion by tumorsphere assays. Expression of S1PR1, S1PR3, Sphk1, and Sphk2 were measured by quantitative PCR, western blot, and immunohistochemistry.ResultsS1PR1, S1PR3, and Sphk2 were overexpressed in all pancreatic cancer cell lines. Sphk1 translocated from the cytoplasm to the nucleus in cells located at the leading edge of cell clusters. Exogenous S1P increased cell migration while treatment with FTY720 and Sphk1 siRNA decreased cell growth and invasion.ConclusionsOur results suggest that increased S1PR1 expression may be an early event in pancreatic cancer pathogenesis. Additionally, altered Sphk1 localization may provide a mechanism through which pancreatic ductal adenocarcinoma cells at the leading edge invade into the surrounding matrix. Finally, inhibition of sphingosine-1-phosphate signaling may provide a novel therapeutic target for patients with metastatic disease.


2005 ◽  
Vol 118 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Hany Kayed ◽  
Jörg Kleeff ◽  
Armin Kolb ◽  
Knut Ketterer ◽  
Shereen Keleg ◽  
...  

2021 ◽  
Vol 11 ◽  
Author(s):  
Jianyou Gu ◽  
Wenjie Huang ◽  
Junfeng Zhang ◽  
Xianxing Wang ◽  
Tian Tao ◽  
...  

Transmembrane protease serine 4 (TMPRSS4) is upregulated in various kinds of human cancers, including pancreatic cancer. However, its biological function in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In the current study, real-time qPCR, immunohistochemical staining, Western blotting, and database (Cancer Genome Atlas and Gene Expression) analysis revealed remarkable overexpression of TMPRSS4 in PDAC tissue as compared to non-tumor tissue. The TMPRSS4 overexpression was associated with poor prognosis of PDAC patients. Moreover, multivariate analysis revealed that TMPRSS4 serves as an independent risk factor in PDAC. We performed gain-and loss-of-function analysis and found that TMPRSS4 promotes cellular proliferation and inhibits apoptosis of PDAC cells both in vitro and in vivo. Furthermore, we showed that TMPRSS4 might promote cell proliferation and inhibit apoptosis through activating ERK1/2 signaling pathway in pancreatic cancer cells. These findings were validated by using ERK1/2 phosphorylation inhibitor SCH772984 both in vitro and in vivo. Taken together, this study suggests that TMPRSS4 is a proto-oncogene, which promotes initiation and progression of PDAC by controlling cell proliferation and apoptosis. Our findings indicate that TMPRSS4 could be a promising prognostic biomarker and a therapeutic target for the treatment of pancreatic cancer.


2016 ◽  
Vol 38 (6) ◽  
pp. 2366-2374 ◽  
Author(s):  
Wenzhuo Yang ◽  
Yanning Yang ◽  
Lu Xia ◽  
Yuefeng Yang ◽  
Fei Wang ◽  
...  

Background/Aims: MicroRNAs (miRNAs, miRs) have emerged as critical regulators of cancer cell proliferation. The effect of miR-221 on cancer cell growth could be significantly changeable in different cell lines. Although miR-221 was reported to promote the cell growth of pancreatic ductal adenocarcinoma (PDAC) cells, its role in Capan-2 cell line is largely unknown. Methods: Capan-2 cells were transfected with miR-221 mimics, inhibitors, or negative controls. Cell Counting Kit-8 was used to determine cell viability. EdU staining and cell cycle analysis were used to measure cell proliferation. Western blotting was used to detect the expression levels of PTEN and phospho-Akt. The PI3K-Akt pathway activator SC-79 and inhibitor LY294002 were used to perform the rescue experiment in determining cell proliferation. Results: Overexpressing miR-221 significantly increased cell vitality and promoted cell proliferation and G1-to-S phase transition of the cell cycle in Capan-2 cells, while inhibition of miR-221 decreased that. The protein level of PTEN in Capan-2 cells was downregulated by overexpressing miR-221, while upregulated by inhibiting miR-221. Consistently, enhanced phosphorylation of AktSer473 was observed in miR-221 overexpressed Capan-2 cells, and the opposite result was found in miR-221 inhibited cells. LY294002 restored the pro-proliferation effect of miR-221 on Capan-2 cells, while SC-79 had no additional effect on cell proliferation in Capan-2 cells transfected with miR-221 mimics. Conclusion: Our study indicates that miR-221 is an oncogenic miRNA which promotes Capan-2 cells proliferation by targeting PTEN-Akt pathway.


2021 ◽  
Vol 2 (2) ◽  
pp. 82-93
Author(s):  
Luca Digiacomo ◽  
Francesca Giulimondi ◽  
Daniela Pozzi ◽  
Alessandro Coppola ◽  
Vincenzo La Vaccara ◽  
...  

Due to late diagnosis, high incidence of metastasis, and poor survival rate, pancreatic cancer is one of the most leading cause of cancer-related death. Although manifold recent efforts have been done to achieve an early diagnosis of pancreatic cancer, CA-19.9 is currently the unique biomarker that is adopted for the detection, despite its limits in terms of sensitivity and specificity. To identify potential protein biomarkers for pancreatic ductal adenocarcinoma (PDAC), we used three model liposomes as nanoplatforms that accumulate proteins from human plasma and studied the composition of this biomolecular layer, which is known as protein corona. Indeed, plasma proteins adsorb on nanoparticle surface according to their abundance and affinity to the employed nanomaterial, thus even small differences between healthy and PDAC protein expression levels can be, in principle, detected. By mass spectrometry experiments, we quantified such differences and identified possible biomarkers for PDAC. Some of them are already known to exhibit different expressions in PDAC proteomes, whereas the role of other relevant proteins is still not clear. Therefore, we predict that the employment of nanomaterials and their protein corona may represent a useful tool to amplify the detection sensitivity of cancer biomarkers, which may be used for the early diagnosis of PDAC, with clinical implication for the subsequent therapy in the context of personalized medicine.


2015 ◽  
Vol 148 (4) ◽  
pp. S-13
Author(s):  
Ujjwal M. Mahajan ◽  
Enno Langhoff ◽  
Eithne Costello ◽  
William Greenhalf ◽  
Christopher Halloran ◽  
...  

2021 ◽  
Vol 22 (1) ◽  
pp. 118-121
Author(s):  
V. U. Rayn ◽  
◽  
M. A. Persidskiy ◽  
E. V. Malakhova ◽  
I. V. Anuchina ◽  
...  

Aim. To establish the association between pancreatic cancer precursor lesions and chronic opisthorchiasis. Materials and methods. A single center case-control study was conducted at a low-volume pancreatic surgery center in Khanty-Mansiysk. We retrospectively collected morphological data from 47 pancreatoduodenectomies performed for pancreatic ductal adenocarcinoma. The study group included 23 cases of pancreatic ductal adenocarcinoma with concomitant chronic Opisthorchis felineus invasion which were compared to 24 controls consisting of “pure” cancer. Qualitative analysis was performed using χ2 Pearson criterion. Exact Fisher test was used for small samples. Time to progression and overall survival rates were calculated using Kaplan-Meier survival analysis. Data were collected and analyzed in Statistica 7.0. Results. PanINs were seen in 41,7% pancreata resected for ductal adenocarcinoma of the head and in 95,7% cases of pancreatic cancer in background of chronic opisthorchiasis (р = 0,000; 95% CI 3,5-268). PanIN high grade were observed only in opisthorchiasis group. In mixed pathology invasive cancer component tended to be more dedifferentiated and advanced when compared to pure cancer group (p = 0,029). Median disease free survival was 9 mo. in both groups and overall survival was 13 mo. in non-opisthorchiasis group and 15,3 mo. in opisthorchiasis group (р = 0,437). Conclusion. Chronic opisthorchiasis is associated with pancreatic intraepithelial neoplasia. Pancreatic ductal adenocarcinoma in background of opisthorchiasis with preneoplastic lesions tend to be more advanced in stage and poorly differentiated. Disease free and overall survival have no statistically significant differences in patients with and without Opisthorchis felineus invasion.


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