scholarly journals Inhibition of Sphingosine-1-Phosphate signaling in pancreatic ductal adenocarcinoma leads to downregulation of growth and invasion

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.

2020 ◽  
Author(s):  
Brenna A. Rheinheimer ◽  
Lukas Vrba ◽  
Bernard W Futscher ◽  
Ronald L Heimark

AbstractBackgroundSLIT2 has been shown to serve as a tumor suppressor in breast, lung, colon, and liver cancers. Additionally, expression of SLIT2 has been shown to be epigenetically regulated in prostate cancer. Therefore, we sought to determine transcriptional regulation of SLIT2 in pancreatic ductal adenocarcinoma.MethodsRNA expression of SLIT2, SLIT3, and ROBO1 was examined in a panel of pancreatic ductal adenocarcinoma cell lines while protein expression of ROBO1 and SLIT2 was examined in tumor tissue. Methylation of the SLIT2 promoter was determined using Sequenom while histone modifications were queried by chromatin immunoprecipitation. Reexpression of SLIT2 was tested by treatment with 5-aza-2’deoxycytidine and Trichostatin A.ResultsPancreatic cancer cell lines fall into three distinct groups based on SLIT2 and ROBO1 expression. The SLIT2 promoter is methylated in pancreatic ductal adenocarcinoma and SLIT2 expression is dependent on the level of methylation at specific CpG sites. Treatment with 5-aza-2’deoxycytidine (but not Trichostatin A) led to SLIT2 reexpression. The SLIT2 promoter is bivalent in pancreatic ductal adenocarcinoma and histone marks around the transcriptional start site are responsible for transcription.ConclusionsLoss of SLIT2 expression modulated by epigenetic silencing may play a role in pancreatic ductal adenocarcinoma progression.


2020 ◽  
Author(s):  
Heidi Roth ◽  
Fatema Bhinderwala ◽  
Rodrigo Franco ◽  
You Zhou ◽  
Robert Powers

Abstract BackgroundAt less than 7%, pancreatic ductal adenocarcinoma (PDAC) has one of the poorest 5-year cancer survival rates and is set to be the leading cause of cancer related deaths by 2030. The co-chaperone protein DNAJA1 (HSP40) is downregulated four-fold in pancreatic cancer cells, but its impact on pancreatic ductal adenocarcinoma (PDAC) progression remains unclear.MethodsDNAJA1 was overexpressed in pancreatic cancer cell lines, BxPC-3 and MIA PaCa-2, through retroviral transfection. The impact of overexpressing DNAJA1 was investigated using a combination of untargeted metabolomics, stable isotope resolved metabolomics (SIRM), confocal microscopy, flow-cytometry, and cell-based assays.ResultsPancreatic cancer cells overexpressing DNAJA1 exhibited a global metabolomic change. Specifically, differential output from Warburg glycolysis, an increase in redox currency, and an alteration in amino acid levels were observed in both overexpression cell lines. DNAJA1 overexpression also led to mitochondrial fusion, an increase in the expression of Bcl-2, a modest protection from redox induced cell death, a loss of structural integrity due to the loss of actin fibers, and an increase in cell invasiveness in BxPC-3. These differences were more pronounced in BxPC-3, which contains a loss-of-function mutation in the tumor suppressing gene SMAD4.ConclusionsThe overexpression of DNAJA1 promoted cellular proliferation, redox tolerance, invasiveness, and anti-apoptosis, which suggests DNAJA1 has numerous regulatory roles. Overall, our findings suggest a proto-oncogenic role of DNAJA1 in PDAC progression and suggests DNAJA1 may function synergistically with other proteins with altered activity in pancreatic cancer cell lines.


Author(s):  
Xiaodong Tian ◽  
Benno Traub ◽  
Jingwei Shi ◽  
Nadine Huber ◽  
Stefan Schreiner ◽  
...  

AbstractThe c-Jun N-terminal protein kinases (JNKs) JNK1 and JNK2 can act as either tumor suppressors or pro-oncogenic kinases in human cancers. The isoform-specific roles for JNK1 and JNK2 in human pancreatic cancer are still unclear, the question which should be addressed in this project. Human pancreatic cancer cell lines MIA PaCa-2 and PANC-1 clones were established either expressing either JNK1 or -2 shRNA in a stable manner. Basal anchorage-dependent and –independent cell growth, single-cell movement, and invasion using the Boyden chamber assay were analyzed. Xenograft growth was assessed using an orthotopic mouse model. All seven tested pancreatic cancer cell lines expressed JNKs as did human pancreatic cancer samples determined by immunohistochemistry. Pharmacological, unspecific JNK inhibition (SP600125) reduced cell growth of all cell lines but PANC-1. Especially inhibition of JNK2 resulted in overall increased oncogenic potential with increased proliferation and invasion, associated with alterations in cytoskeleton structure. Specific inhibition of JNK1 revealed opposing functions. Overall, JNK1 and JNK2 can exert different functions in human pancreatic cancer and act as counter players for tumor invasion. Specifically modulating the activity of JNKs may be of potential therapeutic interest in the future.


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

1996 ◽  
Vol 270 (5) ◽  
pp. R1078-R1084 ◽  
Author(s):  
J. P. Smith ◽  
A. Shih ◽  
Y. Wu ◽  
P. J. McLaughlin ◽  
I. S. Zagon

The gastrointestinal peptides gastrin and cholecystokinin (CCK) stimulate growth of human pancreatic cancer through a CCK-B/gastrin- like receptor. In the present study we evaluated whether growth of human pancreatic cancer is endogenously regulated by gastrin. Immunohistomical examination of BxPC-3 cells and tumor xenografts revealed specifc gastrin immunoreactivity. Gastrin was detected by radioimmunoassay in pancreatic cancer cell extracts and in pancreatic cancer cell extracts and in the growth media. With use of reverse-transcriptase polymerase chain reaction gastrin gene expression was detected in both cultured BxPC-3 cancer cells and transplanted tumors, as well as seven addition human pancreatic cancer cell lines. Growth of BxPC-3 human pancreatic cancer cell in serum-free medium was inhibited by the addition of the CCK-B/gastrin receptor antagonist L-365,260, and gastrin treatment reversed the inhibitory effect of the antagonist. A selective gastrin antibody (Ab repressed growth of BxPC-3 cells. Gastrin immunoreactivity was detected in fresh human pancreatic cancer specimens but not in normal human pancreatic tissue. These data provide the first evidence that growth of a human pancreatic cancer is tonically stimulated by the autocrine production of gastrin. Evidence for the ubiquity of this system was provided by the detection of gastrin gene expression in multiple human pancreatic cancer cell lines and detection of gastrin in cell lines and fresh pancreatic tumors.


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