Late diagnosis contributes to pancreatic cancer (PaCa) dismal prognosis, urging for reliable, early detection. Serum‐exosome protein and/or miRNA markers might be suitable candidates, which we ...controlled for patients with PaCa. Protein markers were selected according to expression in exosomes of PaCa cell line culture supernatants, but not healthy donors' serum‐exosomes. miRNA was selected according to abundant recovery in microarrays of patients with PaCa, but not healthy donors' serum‐exosomes and exosome‐depleted serum. According to these preselections, serum‐exosomes were tested by flow cytometry for the PaCa‐initiating cell (PaCIC) markers CD44v6, Tspan8, EpCAM, MET and CD104. Serum‐exosomes and exosome‐depleted serum was tested for miR‐1246, miR‐4644, miR‐3976 and miR‐4306 recovery by qRT‐PCR. The majority (95%) of patients with PaCa (131) and patients with nonPa‐malignancies reacted with a panel of anti‐CD44v6, ‐Tspan8, ‐EpCAM and ‐CD104. Serum‐exosomes of healthy donors' and patients with nonmalignant diseases were not reactive. Recovery was tumor grading and staging independent including early stages. The selected miR‐1246, miR‐4644, miR‐3976 and miR‐4306 were significantly upregulated in 83% of PaCa serum‐exosomes, but rarely in control groups. These miRNA were also elevated in exosome‐depleted serum of patients with PaCa, but at a low level. Concomitant evaluation of PaCIC and miRNA serum‐exosome marker panels significantly improved sensitivity (1.00, CI: 0.95–1) with a specificity of 0.80 (CI: 0.67–0.90) for PaCa versus all others groups and of 0.93 (CI: 0.81–0.98) excluding nonPa‐malignancies. Thus, the concomitant evaluation of PaCIC and PaCa‐related miRNA marker panels awaits retrospective analyses of larger cohorts, as it should allow for a highly sensitive, minimally‐invasive PaCa diagnostics.
What's new?
Tumor exosomes—membrane vesicles of endocytic origin abundantly secreted by tumor cells and readily detected in body fluids—have recently emerged as a potential, non‐invasive diagnostic tool. This study shows that the serum of pancreatic cancer (PaCa) patients contains detectable amounts of PaCa stem cell marker‐expressing exosomes. Furthermore, the miRNA profile of serum exosomes in PaCa patients differs significantly from that of healthy donors and patients with non‐malignant disease. A blinded screening study of PaCa patients' serum exosomes revealed a combined evaluation of a panel of PaCa‐associated miRNA and stem cell biomarkers to provide a highly sensitive, minimally‐invasive diagnostic tool.
Current non-invasive diagnostic tests can distinguish between pancreatic cancer (pancreatic ductal adenocarcinoma (PDAC)) and chronic pancreatitis (CP) in only about two thirds of patients. We have ...searched for blood-derived metabolite biomarkers for this diagnostic purpose.
For a case-control study in three tertiary referral centres, 914 subjects were prospectively recruited with PDAC (n=271), CP (n=282), liver cirrhosis (n=100) or healthy as well as non-pancreatic disease controls (n=261) in three consecutive studies. Metabolomic profiles of plasma and serum samples were generated from 477 metabolites identified by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.
A biomarker signature (nine metabolites and additionally CA19-9) was identified for the differential diagnosis between PDAC and CP. The biomarker signature distinguished PDAC from CP in the training set with an area under the curve (AUC) of 0.96 (95% CI 0.93-0.98). The biomarker signature cut-off of 0.384 at 85% fixed specificity showed a sensitivity of 94.9% (95% CI 87.0%-97.0%). In the test set, an AUC of 0.94 (95% CI 0.91-0.97) and, using the same cut-off, a sensitivity of 89.9% (95% CI 81.0%-95.5%) and a specificity of 91.3% (95% CI 82.8%-96.4%) were achieved, successfully validating the biomarker signature.
In patients with CP with an increased risk for pancreatic cancer (cumulative incidence 1.95%), the performance of this biomarker signature results in a negative predictive value of 99.9% (95% CI 99.7%-99.9%) (training set) and 99.8% (95% CI 99.6%-99.9%) (test set). In one third of our patients, the clinical use of this biomarker signature would have improved diagnosis and treatment stratification in comparison to CA19-9.
Green tea catechins are considered as possible cancer preventive agents for several cancer types but little is known regarding their effects on pancreatic cancer cells. The best studied catechin and ...the major polyphenol present in green tea is epigallocatechin gallate (EGCG). In the present study, we investigated the in vitro anti‐tumoral properties of EGCG on human pancreatic ductal adenocarcinoma (PDAC) cells PancTu‐I, Panc1, Panc89 and BxPC3 in comparison with the effects of two minor components of green tea catechins, catechin gallate (CG) and epicatechin gallate (ECG). We found that all three catechins inhibited proliferation of PDAC cells in a dose‐ and time‐dependent manner. Interestingly, CG and ECG exerted much stronger anti‐proliferative effects than EGCG. Western blot analyses performed with PancTu‐I cells revealed catechin‐mediated modulation of cell cycle regulatory proteins (cyclins, cyclin‐dependent kinases CDK, CDK inhibitors). Again, these effects were clearly more pronounced in CG or ECG than in EGCG‐treated cells. Importantly, catechins, in particular ECG, inhibited TNFα‐induced activation of NF‐κB and consequently secretion of pro‐inflammatory and invasion promoting proteins like IL‐8 and uPA. Overall, our data show that green tea catechins ECG and CG exhibit potent and much stronger anti‐proliferative and anti‐inflammatory activities on PDAC cells than the most studied catechin EGCG. (Cancer Sci 2011; 102: 728–734)
The interaction of the MHC class I‐related chain molecules A and B (MICA and MICB) with the corresponding natural killer group 2, member D (NKG2D) receptor triggers cytotoxic effector activity of ...natural killer cells and certain T‐cell subsets and provides a costimulatory signal for cytokine production. Thus, the presence of MICA/B on transformed cells contributes to tumor immunosurveillance. Consequently, the proteolytic cleavage of MICA/B is regarded as an important immune escape mechanism of various cancer cells. To investigate the molecular machinery responsible for the shedding of endogenous MICA/B, we analyzed different human tumor entities including mammary, pancreatic and prostate carcinomas. Flow cytometry and enzyme‐linked immunosorbent assay (ELISA) revealed that all tested tumor cells constitutively expressed MICA and MICB on the cell surface and also released NKG2D ligands into the supernatant. We demonstrate that the “a disintegrin and metalloproteases” (ADAMs) 10 and 17 are largely responsible for the generation of soluble MICA/B. Pharmacological inhibition of metalloproteases reduced the level of released MICA/B and increased cell surface expression. Studies using RNA interference not only revealed a prominent role of ADAM10 and ADAM17 in NKG2D ligand shedding but also a tumor cell‐specific role of ADAM10 and/or ADAM17 in shedding of MICA or MICB. Moreover, we report that in the prostate carcinoma cell line PC‐3, MICA was not shed at all but rather was secreted in exosomes. These data indicate that the release of NKG2D ligands from individual tumor entities is by far more complex than suggested in previously reported MICA/B transfection systems.
What's new?
Various immune factors patrol for substances found on the surfaces of tumor cells, and because each patient has a unique antitumor immune response, harnessing this surveillance ability represents an attractive strategy for personalized medicine. This study shows, however, that at least for the NKG2D immunosurveillance system, developing personalized therapeutic strategies may be more difficult than initially thought. Tumor shedding of the NKG2D ligands MICA/B, which facilitate tumor immune evasion, was found to be differentially regulated by ADAM proteases 10 and 17, indicating that ligand shedding is tumor cell‐specific and regulated by a multitude of mechanisms.
Many cancers harbor oncogenic mutations of KRAS. Effectors mediating cancer progression, invasion, and metastasis in KRAS-mutated cancers are only incompletely understood. Here we identify cancer ...cell-expressed murine TRAIL-R, whose main function ascribed so far has been the induction of apoptosis as a crucial mediator of KRAS-driven cancer progression, invasion, and metastasis and in vivo Rac-1 activation. Cancer cell-restricted genetic ablation of murine TRAIL-R in autochthonous KRAS-driven models of non-small-cell lung cancer (NSCLC) and pancreatic ductal adenocarcinoma (PDAC) reduces tumor growth, blunts metastasis, and prolongs survival by inhibiting cancer cell-autonomous migration, proliferation, and invasion. Consistent with this, high TRAIL-R2 expression correlates with invasion of human PDAC into lymph vessels and with shortened metastasis-free survival of KRAS-mutated colorectal cancer patients.
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•mTRAIL-R promotes KRAS-driven lung and pancreatic cancer growth and metastasis•Human TRAIL-R2 promotes tumor growth, migration, invasion, and metastasis•Endogenous mTRAIL-R constitutively activates Rac1 in vivo in tumors•TRAIL-R2 expression positively correlates with the onset of metastasis in patients
von Karstedt et al. show that mouse TRAIL-R and human TRAIL-R2, but not TRAIL-R1, are important for the progression, invasion, and metastasis of KRAS-mutant tumors through the regulation of Rac-1.
Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal human tumors, with radical surgical resection as the only curative treatment option. However, resection is only possible in a small ...fraction of patients, and about 80% of the patients develop recurrencies. PDAC development is facilitated by the cytokine interleukin‐6 (IL‐6), which acts via classic and trans‐signaling. Both pathways are inhibited by the anti‐IL‐6‐receptor antibody tocilizumab, whereas the fusion protein sgp130Fc specifically blocks trans‐signaling. Here, we show that conservative or adjuvant therapy with both inhibitors reduces tumor growth in an orthotopic model of human Colo357 cells in SCID/bg mice. In the conservative setting, median primary tumor weight was reduced 2.4‐fold for tocilizumab and 4.4‐fold for sgp130Fc. sgp130Fc additionally led to a decrease in microvessel density, which was not observed with tocilizumab. In the adjuvant therapeutic setting after surgical resection of the primary tumor, treatment with tocilizumab or sgp130Fc decreased the local recurrence rate from 87.5% in the control group to 62.5 or 50%, respectively. Furthermore, the median weight of the local recurrent tumors was clearly diminished, and both inhibitors reduced the number of distant metastases. A significant reduction of tumor weight and metastases—comparable to gemcitabine treatment—was also observed with both inhibitors in another model using the poorly differentiated PancTuI cells. Our findings demonstrate the inhibition of IL‐6 as a new treatment option in PDAC.
What's new?
IL‐6 plays a critical role in the progression of pancreatic cancer, and its inhibition may be key in the therapeutic battle against the disease. IL‐6 acts through both an anti‐inflammatory classic signaling pathway involving membrane‐bound IL‐6R and a pro‐inflammatory trans‐signaling pathway involving soluble IL‐6R and gp130. Using a clinically adapted xenotransplant model, this study shows that inhibition of both pathways, with either tocilizumab or sgp130Fc, which specifically blocks trans‐signaling, leads to significant reductions in human pancreatic tumor growth. Following surgical resection of primary tumors, the inhibitors decreased local tumor recurrence rates and reduced numbers of distant metastases.
Pancreatic ductal adenocarcinoma cancer (PDAC) is a highly lethal malignancy requiring efficient detection when the primary tumor is still resectable. We previously developed the MxPancreasScore ...comprising 9 analytes and serum carbohydrate antigen 19-9 (CA19-9), achieving an accuracy of 90.6%. The necessity for 5 different analytical platforms and multiple analytical runs, however, hindered clinical applicability. We therefore aimed to develop a simpler single-analytical run, single-platform diagnostic signature.
We evaluated 941 patients (PDAC, 356; chronic pancreatitis CP, 304; nonpancreatic disease, 281) in 3 multicenter independent tests, and identification (ID) and validation cohort 1 (VD1) and 2 (VD2) were evaluated. Targeted quantitative plasma metabolite analysis was performed on a liquid chromatography–tandem mass spectrometry platform. A machine learning–aided algorithm identified an improved (i-Metabolic) and minimalistic metabolic (m-Metabolic) signatures, and compared them for performance.
The i-Metabolic Signature, (12 analytes plus CA19-9) distinguished PDAC from CP with area under the curve (95% confidence interval) of 97.2% (97.1%-97.3%), 93.5% (93.4%-93.7%), and 92.2% (92.1%-92.3%) in the ID, VD1, and VD2 cohorts, respectively. In the VD2 cohort, the m-Metabolic signature (4 analytes plus CA19-9) discriminated PDAC from CP with a sensitivity of 77.3% and specificity of 89.6%, with an overall accuracy of 82.4%. For the subset of 45 patients with PDAC with resectable stages IA-IIB tumors, the sensitivity, specificity, and accuracy were 73.2%, 89.6%, and 82.7%, respectively; for those with detectable CA19-9 >2 U/mL, 81.6%, 88.7%, and 84.5%, respectively; and for those with CA19-9 <37 U/mL, 39.7%, 94.1%, and 76.3%, respectively.
The single-platform, single-run, m-Metabolic signature of just 4 metabolites used in combination with serum CA19-9 levels is an innovative accurate diagnostic tool for PDAC at the time of clinical presentation, warranting further large-scale evaluation.
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The m-Metabolic signature, based on just 4 plasma analytes combined with serum carbohydrate antigen 19-9, is highly accurate in diagnosing pancreatic cancer and could contribute to earlier treatment and improved prognosis of patients with pancreatic cancer.
Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers principally because of early invasion and metastasis. The epidermal growth factor receptor (EGFR) is essential for ...PDAC development even in the presence of Kras, but its inhibition with erlotinib gives only a modest clinical response, making the discovery of novel EGFR targets of critical interest. Here, we revealed by mining a human pancreatic gene expression database that the metastasis promoter Na+ /H+ exchanger (NHE1) associates with the EGFR in PDAC. In human PDAC cell lines, we confirmed that NHE1 drives both basal and EGF-stimulated three-dimensional growth and early invasion via invadopodial extracellular matrix digestion. EGF promoted the complexing of EGFR with NHE1 via the scaffolding protein Na +/H + exchanger regulatory factor 1, engaging EGFR in a negative transregulatory loop that controls the extent and duration of EGFR oncogenic signaling and stimulates NHE1. The specificity of NHE1 for growth or invasion depends on the segregation of the transient EGFR/Na +/H + exchanger regulatory factor 1/NHE1 signaling complex into dimeric subcomplexes in different lipid raftlike membrane domains. This signaling complex was also found in tumors developed in orthotopic mice. Importantly, the specific NHE1 inhibitor cariporide reduced both three-dimensional growth and invasion independently of PDAC subtype and synergistically sensitized these behaviors to low doses of erlotinib.
The human pancreatic cancer cell line A818-6 can be grown in vitro either as a highly malignant, undifferentiated monolayer (ML) or as three-dimensional (3D) single layer hollow spheres (HS) ...simulating a benign, highly differentiated, duct-like pancreatic epithelial structure. This characteristic allowing A818-6 cells to switch from one phenotype to another makes these cells a unique system to characterize the cellular and molecular modifications during differentiation on one hand and malignant transformation on the other hand. Ion channels and transport proteins (transportome) have been implicated in malignant transformation. Therefore, the current study aimed to analyse the transportome gene expression profile in the A818-6 cells growing as a monolayer or as hollow spheres.
The study identified the differentially expressed transportome genes in both cellular states of A818-6 using Agilent and Nanostring arrays and some targets were validated via immunoblotting. Additionally, these results were compared to a tissue Affymetrix microarray analysis of pancreatic adenocarcinoma patients' tissues. The overall transcriptional profile of the ML and HS cells confirmed the formerly described mesenchymal features of ML and epithelial nature of HS which was further verified via high expression of E-cadherin and low expression of vimentin found in HS in comparison to ML. Among the predicted features between HS and ML was the involvement of miRNA-9 in this switch. Importantly, the bioinformatics analysis also revealed substantial number (n = 126) of altered transportome genes. Interestingly, three genes upregulated in PDAC tissue samples (GJB2, GJB5 and SLC38A6) were found to be also upregulated in ML and 3 down-regulated transportome genes (KCNQ1, TRPV6 and SLC4A) were also reduced in ML.
This reversible HS/ML in vitro system might help in understanding the pathophysiological impact of the transportome in the dedifferentiation process in pancreatic carcinogenesis. Furthermore, the HS/ML model represents a novel system for studying the role of the transportome during the switch from a more benign, differentiated (HS) to a highly malignant, undifferentiated (ML) phenotype.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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