69 research outputs found
Genetic disruption of the PI3K regulatory subunits, p85 alpha, p55 alpha, and p50 alpha partially normalizes gain-of-function PTPN11- induced hypersensitivity to GM-CSF in hematopoietic progenitors
poster abstractJuvenile Myelomonocytic Leukemia (JMML) is a lethal myeloproliferative disorder (MPD) of children, characterized by hyperproliferation of myelomonocytic cells and hypersensitivity to Granulocyte-Monocyte Colony-Stimulating Factor (GM-CSF). JMML is frequently associated with gain-of-function mutations in PTPN11, which encodes the protein tyrosine phosphatase, Shp2, and which is known to positively regulate Ras signaling. The role of MAPK signaling in gain-of-function mutant Shp2-induced leukemogenesis is well established. In addition, phosphoAkt levels are elevated in the presence of gain-of-function Shp2 mutations, suggesting a role for Phosphatidyl-Inositol-3-Kinase (PI3K) signaling (Yang, et al, 2008). Class IA PI3K is a lipid kinase heterodimer composed of one of two regulatory subunits—p85 alpha or p85 beta—and one of three catalytic subunits—p110 alpha, p110 beta, or p110 delta. PI3K mediates proliferative and anti-apoptotic signals. We have found that there is increased interaction between the p85 alpha regulatory subunit and the p110 alpha catalytic subunit in gain-offunction mutant Shp2-expressing cells compared to WT Shp2-expressing cells. The p85 alpha regulatory subunit, along with its splice variants, p55 alpha and p50 alpha, is encoded by the gene Pik3r1. To investigate the hypothesis that p85 alpha-dependent PI3K signaling contributes to gain-of-function mutant Shp2-induced GM-CSF hypersensitivity, WT and Pik3r1-/- fetal liver-derived hematopoietic progenitor cells were transduced with WT Shp2 or gain-of-function mutant Shp2 E76K. Ablation of all the Pik3r1 isoforms resulted in a significant, but incomplete, correction of GM-CSF hypersensitivity in Shp2 E76K-expressing cells. Consistently, upon genetic disruption of Pik3r1, Akt phosphorylation was reduced in both WT Shp2- and Shp2 E76K-expressing cells compared to that seen in Pik3r1+/+ cells, but was not completely absent. Additionally, Erk activation was reduced in Pik3r1-/- cells expressing Shp2 E76K compared to that in Pik3r1+/+ cells, indicating that interruption of Shp2-mediated PI3K signaling affects the MAPK pathway as well, which likely contributes to the reduction in GM-CSF-stimulated proliferation in the Pik3r1-/- cells. Finally, treatment with the PI3K inhibitor, LY294002 resulted in complete abrogation of Akt phosphorylation in Pik3r1-/- cells transduced with Shp2 E76K, indicating that residual PI3K activity in the absence of Pik3r1 likely contributes to the incomplete correction of GM-CSF hypersensitivity and suggesting that although p85 alpha plays an important role in gain-of-function mutant Shp2-induced hyperactivation of PI3K signaling, additional p85 alpha-independent mechanisms contribute as well
Risk of hepatitis B virus reactivation and its effect on survival in advanced hepatocellular carcinoma patients treated with hepatic arterial infusion chemotherapy and lenvatinib plus programmed death receptor-1 inhibitors
BackgroundHepatitis B virus (HBV) reactivation is a common complication in hepatocellular carcinoma (HCC) patients treated with chemotherapy or immunotherapy. This study aimed to evaluate the risk of HBV reactivation and its effect on survival in HCC patients treated with HAIC and lenvatinib plus PD1s.MethodsWe retrospectively collected the data of 213 HBV-related HCC patients who underwent HAIC and lenvatinib plus PD1s treatment between June 2019 to June 2022 at Sun Yat-sen University, China. The primary outcome was the risk of HBV reactivation. The secondary outcomes were overall survival (OS), progression−free survival (PFS), and treatment−related adverse events.ResultsSixteen patients (7.5%) occurred HBV reactivation in our study. The incidence of HBV reactivation was 5% in patients with antiviral prophylaxis and 21.9% in patients without antiviral prophylaxis, respectively. The logistic regression model indicated that for HBV reactivation, lack of antiviral prophylaxis (P=0.003) and tumor diameter (P=0.036) were independent risk factors. The OS and PFS were significantly shorter in the HBV reactivation group than the non-reactivation group (P=0.0023 and P=0.00073, respectively). The number of AEs was more in HBV reactivation group than the non-reactivation group, especially hepatic AEs.ConclusionHBV reactivation may occur in HCC patients treated with HAIC and lenvatinib plus PD1s. Patients with HBV reactivation had shorter survival time compared with non-reactivation. Therefore, HBV-related HCC patients should undergo antiviral therapy and HBV-DNA monitoring before and during the combination treatment
Survival benefit of neoadjuvant hepatic arterial infusion chemotherapy followed by hepatectomy for hepatocellular carcinoma with portal vein tumor thrombus
Background/purpose: The prognosis of hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) is generally poor and hepatectomy is optional for these patients. This study aims to explore the survival benefits of neoadjuvant hepatic arterial infusion chemotherapy (HAIC) for resectable HCC with PVTT.Methods: This retrospective study included 120 resectable HCC patients with PVTT who underwent hepatectomy, from January 2017 to January 2021 at Sun Yat-sen University Cancer Center. Of these patients, the overall survival (OS) and recurrence-free survival (RFS) of 55 patients who received hepatectomy alone (Surgery group) and 65 patients who received neoadjuvant HAIC followed by hepatectomy (HAIC-Surgery group) were compared. Logistic regression analysis was conducted to develop a model predicting the response to neoadjuvant HAIC.Results: The OS rates for the HAIC-Surgery group at 1, 3, and 5Â years were 94.9%, 78%, and 66.4%, respectively, compared with 84.6%, 47.6%, and 37.2% in the Surgery group (p < 0.001). The RFS rates were 88.7%, 56.2%, and 38.6% versus 84.9%, 38.3%, and 22.6% (p = 0.002). The subgroup analysis revealed that the survival benefit of neoadjuvant HAIC was limited to patients who responded to it. The logistic model, consisting of AFP and CRP, that predicted the response to neoadjuvant HAIC performed well, with an area under the ROC curve (AUC) of 0.756.Conclusion: Neoadjuvant HAIC followed by hepatectomy is associated with a longer survival outcome than hepatectomy alone for HCC patients with PVTT and the survival benefit is limited to patients who respond to neoadjuvant FOLFOX-HAIC
Notch ligand Delta-like 1 promotes in vivo vasculogenesis in human cord blood-derived endothelial colony forming cells
BACKGROUND AIMS: Human cord blood (CB) is enriched in circulating endothelial colony forming cells (ECFCs) that display high proliferative potential and in vivo vessel forming ability. Because Notch signaling is critical for embryonic blood vessel formation in utero, we hypothesized that Notch pathway activation may enhance cultured ECFC vasculogenic properties in vivo.
METHODS: In vitro ECFC stimulation with an immobilized chimeric Notch ligand (Delta-like1(ext-IgG)) led to significant increases in the mRNA and protein levels of Notch regulated Hey2 and EphrinB2 that were blocked by treatment with γ-secretase inhibitor addition. However, Notch stimulated preconditioning in vitro failed to enhance ECFC vasculogenesis in vivo. In contrast, in vivo co-implantation of ECFCs with OP9-Delta-like 1 stromal cells that constitutively expressed the Notch ligand delta-like 1 resulted in enhanced Notch activated ECFC-derived increased vessel density and enlarged vessel area in vivo, an effect not induced by OP9 control stromal implantation.
RESULTS: This Notch activation was associated with diminished apoptosis in the exposed ECFC.
CONCLUSIONS: We conclude that Notch pathway activation in ECFC in vivo via co-implanted stromal cells expressing delta-like 1 promotes vasculogenesis and augments blood vessel formation via diminishing apoptosis of the implanted ECFC
Protein-tyrosine Phosphatase Shp2 Positively Regulates Macrophage Oxidative Burst
Macrophages are vital to innate immunity and express pattern recognition receptors and integrins for the rapid detection of invading pathogens. Stimulation of Dectin-1 and complement receptor 3 (CR3) activates Erk- and Akt-dependent production of reactive oxygen species (ROS). Shp2, a protein-tyrosine phosphatase encoded by Ptpn11, promotes activation of Ras-Erk and PI3K-Akt and is crucial for hematopoietic cell function; however, no studies have examined Shp2 function in particulate-stimulated ROS production. Maximal Dectin-1-stimulated ROS production corresponded kinetically to maximal Shp2 and Erk phosphorylation. Bone marrow-derived macrophages (BMMs) from mice with a conditionally deleted allele of Ptpn11 (Shp2flox/flox;Mx1Cre+) produced significantly lower ROS levels compared with control BMMs. Although YFP-tagged phosphatase dead Shp2-C463A was strongly recruited to the early phagosome, its expression inhibited Dectin-1- and CR3-stimulated phospho-Erk and ROS levels, placing Shp2 phosphatase function and Erk activation upstream of ROS production. Further, BMMs expressing gain of function Shp2-D61Y or Shp2-E76K and peritoneal exudate macrophages from Shp2D61Y/+;Mx1Cre+ mice produced significantly elevated levels of Dectin-1- and CR3-stimulated ROS, which was reduced by pharmacologic inhibition of Erk. SIRPα (signal regulatory protein α) is a myeloid inhibitory immunoreceptor that requires tyrosine phosphorylation to exert its inhibitory effect. YFP-Shp2C463A-expressing cells have elevated phospho-SIRPα levels and an increased Shp2-SIRPα interaction compared with YFP-WT Shp2-expressing cells. Collectively, these findings indicate that Shp2 phosphatase function positively regulates Dectin-1- and CR3-stimulated ROS production in macrophages by dephosphorylating and thus mitigating the inhibitory function of SIRPα and by promoting Erk activation
Role of p85α in neutrophil extra- and intracellular reactive oxygen species generation
Drug resistance is a growing problem that necessitates new strategies to combat pathogens. Neutrophil phagocytosis and production of intracellular ROS, in particular, has been shown to cooperate with antibiotics in the killing of microbes. This study tested the hypothesis that p85α, the regulatory subunit of PI3K, regulates production of intracellular ROS. Genetic knockout of p85α in mice caused decreased expression of catalytic subunits p110α, p110β, and p110δ, but did not change expression levels of the NADPH oxidase complex subunits p67phox, p47phox, and p40phox. When p85α, p55α, and p50α (all encoded by Pik3r1) were deleted, there was an increase in intracellular ROS with no change in phagocytosis in response to both Fcγ receptor and complement receptor stimulation. Furthermore, the increased intracellular ROS correlated with significantly improved neutrophil killing of both methicillin-susceptible and methicillin-resistant S. aureus. Our findings suggest inhibition of p85α as novel approach to improving the clearance of resistant pathogens
Enhancing Logical Reasoning of Large Language Models through Logic-Driven Data Augmentation
Combining large language models with logical reasoning enhance their capacity
to address problems in a robust and reliable manner. Nevertheless, the
intricate nature of logical reasoning poses challenges to gathering reliable
data from web for building comprehensive training datasets, subsequently
affecting the performance on downstream tasks. To address this, we introduce a
novel logic-driven data augmentation approach, AMR-LDA. AMR-LDA converts the
original text into an Abstract Meaning Representation (AMR) graph, a structured
semantic representation that encapsulates the logic structure of the sentence,
upon which operations are performed to generate logically modified AMR graphs.
The modified AMR graphs are subsequently converted back into texts to create
augmented data. Notably, our methodology is architecture-agnostic and enhances
generative large language models, such as GPT-3.5 and GPT-4, through prompt
augmentation, and fine-tuning discriminative large language models through
contrastive learning with logic-driven data augmentation. Empirical evidence
underscores the efficacy of our proposed method with improvement in performance
across seven downstream tasks, such as logical reasoning reading comprehension,
textual entailment, and natural language inference. Furthermore, our method
ranked first on the ReClor leaderboard
\url{https://eval.ai/web/challenges/challenge-page/503/leaderboard/1347}. The
source code and data are publicly available
\url{https://github.com/Strong-AI-Lab/Logical-Equivalence-driven-AMR-Data-Augmentation-for-Representation-Learning}.Comment: Accepted for oral presentation at the LLM@IJCAI 2023 non-archival
symposiu
Comparison of hepatic arterial infusion chemotherapy with mFOLFOX vs. first-line systemic chemotherapy in patients with unresectable intrahepatic cholangiocarcinoma
Background: Systemic chemotherapy (SC) remains the only first-line treatment for unresectable intrahepatic cholangiocarcinoma (iCCA). Hepatic arterial infusion chemotherapy (HAIC) has been recently proven to be effective in managing hepatocellular carcinoma (HCC). Hence, our study aims to investigate the safety and efficacy of HAIC in treating unresectable iCCA patients.Methods: We reviewed 146 patients with unresectable iCCA who had received HAIC or SC between March 2016 and March 2022 in a retrospective manner. Outcomes of patients and safety were compared between the HAIC and SC groups.Results: There were 75 and 71 patients in the HAIC and SC groups, respectively. The median OS in the HAIC and SC groups was 18.0 and 17.8 months (p = 0.84), respectively. The median PFS in the HAIC and SC groups was 10.8 and 11.4Â months (p = 0.59), respectively. However, the HAIC group had significantly longer intrahepatic progression-free survival (IPFS) than the SC group (p = 0.035). The median IPFS in the HAIC and SC groups was 13.7 and 11.4Â months, respectively. According to the OS (p = 0.047) and PFS (p = 0.009), single-tumor patients in the HAIC group appeared to benefit more. In addition, the overall incidence of adverse events (AEs) was lower in the HAIC group than that in the SC group.Conclusion: Our study revealed that HAIC was a safe and effective therapeutic regimen for unresectable iCCA with better intrahepatic tumor control when compared to SC. Meanwhile, patients with single tumor were more likely to benefit from HAIC than SC
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