126 research outputs found

    SMAD4 loss enables EGF, TGF\u3b21 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells

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    Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor \u3b21 (TGF\u3b21) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGF\u3b21 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGF\u3b21 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/\u3b2-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGF\u3b21 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-\u3baB and PI3K/AKT in response to TGF\u3b21 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/\u3b2-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGF\u3b21 and S100A8/A9 mainly inhibit NF-\u3baB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner

    SARS-CoV-2 RNA identification in nasopharyngeal swabs: issues in pre-analytics.

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    Abstract Objectives The direct identification of SARS-CoV-2 RNA in nasopharyngeal swabs is recommended for diagnosing the novel COVID-19 disease. Pre-analytical determinants, such as sampling procedures, time and temperature storage conditions, might impact on the end result. Our aim was to evaluate the effects of sampling procedures, time and temperature of the primary nasopharyngeal swabs storage on real-time reverse-transcription polymerase chain reaction (rRT-PCR) results. Methods Each nasopharyngeal swab obtained from 10 hospitalized patients for COVID-19 was subdivided in 15 aliquots: five were kept at room temperature; five were refrigerated (+4 °C); five were immediately mixed with the extraction buffer and refrigerated at +4 °C. Every day and for 5 days, one aliquot per condition was analyzed (rRT-PCR) for SARS-CoV-2 gene E and RNaseP and threshold cycles (Ct) compared. To evaluate manual sampling, 70 nasopharyngeal swabs were sampled twice by two different operators and analyzed separately one from the other. Results A total of 6/10 swabs were SARS-CoV-2 positive. No significant time or storage-dependent variations were observed in SARS-CoV-2 Ct. Re-sampling of swabs with SARS-CoV-2 Ct lower than 33 resulted in highly reproducible results (CV=2.9%), while a high variability was observed when Ct values were higher than 33 (CV=10.3%). Conclusions This study demonstrates that time and temperature of nasopharyngeal swabs storage do not significantly impact on results reproducibility. However, swabs sampling is a critical step, and especially in case of low viral load, might be a potential source of diagnostic errors

    Inflammation and pancreatic cancer: molecular and functional interactions between S100A8, S100A9, NT-S100A8 and TGFβ1

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    BACKGROUND: In order to gain further insight on the crosstalk between pancreatic cancer (PDAC) and stromal cells, we investigated interactions occurring between TGF\u3b21 and the inflammatory proteins S100A8, S100A9 and NT-S100A8, a PDAC-associated S100A8 derived peptide, in cell signaling, intracellular calcium (Cai2+) and epithelial to mesenchymal transition (EMT). NF-\u3baB, Akt and mTOR pathways, Cai2+ and EMT were studied in well (Capan1 and BxPC3) and poorly differentiated (Panc1 and MiaPaCa2) cell lines. RESULTS: NT-S100A8, one of the low molecular weight N-terminal peptides from S100A8 to be released by PDAC-derived proteases, shared many effects on NF-\u3baB, Akt and mTOR signaling with S100A8, but mainly with TGF\u3b21. The chief effects of S100A8, S100A9 and NT-S100A8 were to inhibit NF-\u3baB and stimulate mTOR; the molecules inhibited Akt in Smad4-expressing, while stimulated Akt in Smad4 negative cells. By restoring Smad4 expression in BxPC3 and silencing it in MiaPaCa2, S100A8 and NT-S100A8 were shown to inhibit NF-\u3baB and Akt in the presence of an intact TGF\u3b21 canonical signaling pathway. TGF\u3b21 counteracted S100A8, S100A9 and NT-S100A8 effects in Smad4 expressing, not in Smad4 negative cells, while it synergized with NT-S100A8 in altering Cai2+ and stimulating PDAC cell growth. The effects of TGF\u3b21 on both EMT (increased Twist and decreased N-Cadherin expression) and Cai2+ were antagonized by S100A9, which formed heterodimers with TGF\u3b21 (MALDI-TOF/MS and co-immuno-precipitation). CONCLUSIONS: The effects of S100A8 and S100A9 on PDAC cell signaling appear to be cell-type and context dependent. NT-S100A8 mimics the effects of TGF\u3b21 on cell signaling, and the formation of complexes between TGF\u3b21 with S100A9 appears to be the molecular mechanism underlying the reciprocal antagonism of these molecules on cell signaling, Cai2+ and EMT

    A Randomized Trial of Pharmacogenetic Warfarin Dosing in Naive Patients with Non-Valvular Atrial Fibrillation

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    Genotype-guided warfarin dosing have been proposed to improve patient's management. This study is aimed to determine whether a CYP2C9- VKORC1- CYP4F2-based pharmacogenetic algorithm is superior to a standard, clinically adopted, pharmacodynamic method. Two-hundred naive patients with non-valvular atrial fibrillation were randomized to trial arms and 180 completed the study. No significant differences were found in the number of out-of-range INRs (INR3.0) (p = 0.79) and in the mean percentage of time spent in the therapeutic range (TTR) after 19 days in the pharmacogenetic (51.9%) and in the control arm (53.2%, p = 0.71). The percentage of time spent at INR>4.0 was significantly lower in the pharmacogenetic (0.7%) than in the control arm (1.8%) (p = 0.02). Genotype-guided warfarin dosing is not superior in overall anticoagulation control when compared to accurate clinical standard of care

    Lack of association of CD44-rs353630 and CHI3L2-rs684559 with pancreatic ductal adenocarcinoma survival.

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    Although pancreatic ductal adenocarcinoma (PDAC) survival is poor, there are differences in patients' response to the treatments. Detection of predictive biomarkers explaining these differences is of the utmost importance. In a recent study two genetic markers (CD44-rs353630 and CHI3L2-rs684559) were reported to be associated with survival after PDAC resection. We attempted to replicate the associations in 1856 PDAC patients (685 resected with stage I/II) from the PANcreatic Disease ReseArch (PANDoRA) consortium. We also analysed the combined effect of the two genotypes in order to compare our results with what was previously reported. Additional stratified analyses considering TNM stage of the disease and whether the patients received surgery were also performed. We observed no statistically significant associations, except for the heterozygous carriers of CD44-rs353630, who were associated with worse OS (HR = 5.01; 95% CI 1.58-15.88; p = 0.006) among patients with stage I disease. This association is in the opposite direction of those reported previously, suggesting that data obtained in such small subgroups are hardly replicable and should be considered cautiously. The two polymorphisms combined did not show any statistically significant association. Our results suggest that the effect of CD44-rs353630 and CHI3L2-rs684559 cannot be generalized to all PDAC patients

    Epidermal growth factor (EGF) chronic stimulation causes Smad4- dependent signaling bypass in pancreatic ductal adenocarcinoma (PDAC)

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    Context EGF and EGFR overexpression is an early, while Smad4 inactivation is a late event in PDAC progression. Acquired resistance to EGFR-targeted therapies might depend on the activation of bypass signaling pathways. Objective To verify whether a prolunged exposure of PDAC cells to EGF activates bypass signaling and whether this event is Sma4 dependent. Methods BxPC3 Smad4 Homozygous deletion (HD) and Smad4-transfected BxPC3 (BxPC3-Smad4+) remained unstimulated (C) or were daily stimulated (S) for three days with EGF (100ng/mL). Then, EGF treatment (100 ng/mL for 10 minutes) was followed by cell collection for Reverse Phase Protein Array (RPPA) analysis of: MAPK, NF-kB, SRC/JAK/STAT3, PI3K/AKT, inflammasome signaling pathways. RPPA data analysis consisted of calculating the concentration of each sample, after background correction and normalization (signal intensities gained from a image software). Intensities of stimulated cells were referred to controls and variations higher than 30% were considered. Results In C-BxPC3, EGF activated MAPK/ERK (pERK1/2) only. In C-BxPC3-Smad4+, EGF activated SRC/JAK/STAT3 (pc-SRC;pRIP2;pJAK2), MAPK/ERK (pERK1/2;pMEK 1/2) and SAPK/JNK (pc-Jun;pSEK/MKK4), not p38 MAPK (pP38;TRAF2;pTAK1). In S-BxPC3 and in S-BxPC3-Smad4+, EGF did not activate any MAPK pathway not SRC/JAK/STAT3. In S-BxPC3-Smad4+, EGF activated NF-KB (pIkBa;IKKg;pIRAK1;A20) and inhibited the inflammasome (pSTAT4;ACS;Caspase1;MyD88), while in S-BxPC3 EGF inhibited only the inflammasome pathway. The PI3K/AKT pathway was never affected by EGF. RPPA results were confirmed by western blot (WB) (pP38;pERK1/2;pAKT308;pAKT473). Conclusion EGRF chronic stimulation causes Smad4-dependent signaling bypass from MAPK to NF-KB in Smad4-expressing cells. Smad4 HD renders PDAC cells low responsive to EGF acute or chronic stimulation. These findings might explain the PDAC-low response rate to EGRF-targeted therapies
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