Protein tyrosine phosphatase 1 protects human pancreatic cancer from erastin-induced ferroptosis.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the lack of early detection method, therapeutic drug and target. We noticed that the expression of Protein Tyrosine Phosphatase Mitochondria1(PTPMT1) is upregulated in PDAC. However, its role in pancreatic cancer remains unknown. METHODS: We first analyzed the expression of PTPMT1 from 50 PDAC patients. Secondly, the survival proportions of different PTPMT1-expressed patients were analyzed. Then, the role and mechanism of PTPMT1 in PDAC were studied by lentivirus transduction system. RESULTS: PTPMT1 was upregulated in PDAC and patients with high PTPMT1 expression displayed lower overall survival rate. Knockdown of PTPMT1 increased the sensitivity to erastin or RSL3 induced ferroptosis. Mechanically, knockdown of PTPMT1 resulted in upregulated Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4) and downregulated Solute Carrier Family 7 Member 11 (SLC7A11). In addition, SLC7A11 was upregulated in PDAC tumor tissue and correlated positively with the expression of PTPMT1. However, the expression of ACSL4 was downregulated in PDAC and negatively correlated with the expression of PTPMT1. CONCLUSION: Our study demonstrates that PTPMT1 is upregulated in PDAC and PTPMT1 inhibits ferroptosis by suppressing the expression of ACSL4 and upregulating SLC7A11 in Panc-1 cells, suggesting PTPMT1 might be a potential prognosis biomarker and therapeutic target in PDAC.

Synthesizing High-b-Value Diffusion-weighted Imaging of the Prostate Using Generative Adversarial Networks.

PURPOSE: To develop and evaluate a diffusion-weighted imaging (DWI) deep learning framework based on the generative adversarial network (GAN) to generate synthetic high-b-value (b =1500 sec/mm2) DWI (SYNb1500) sets from acquired standard-b-value (b = 800 sec/mm2) DWI (ACQb800) and acquired standard-b-value (b = 1000 sec/mm2) DWI (ACQb1000) sets. MATERIALS AND METHODS: This retrospective multicenter study included 395 patients who underwent prostate multiparametric MRI. This cohort was split into internal training (96 patients) and external testing (299 patients) datasets. To create SYNb1500 sets from ACQb800 and ACQb1000 sets, a deep learning model based on GAN (M0) was developed by using the internal dataset. M0 was trained and compared with a conventional model based on the cycle GAN (Mcyc). M0 was further optimized by using denoising and edge-enhancement techniques (optimized version of the M0 [Opt-M0]). The SYNb1500 sets were synthesized by using the M0 and the Opt-M0 were synthesized by using ACQb800 and ACQb1000 sets from the external testing dataset. For comparison, traditional calculated (b =1500 sec/mm2) DWI (CALb1500) sets were also obtained. Reader ratings for image quality and prostate cancer detection were performed on the acquired high-b-value (b = 1500 sec/mm2) DWI (ACQb1500), CALb1500, and SYNb1500 sets and the SYNb1500 set generated by the Opt-M0 (Opt-SYNb1500). Wilcoxon signed rank tests were used to compare the readers' scores. A multiple-reader multiple-case receiver operating characteristic curve was used to compare the diagnostic utility of each DWI set. RESULTS: When compared with the Mcyc, the M0 yielded a lower mean squared difference and higher mean scores for the peak signal-to-noise ratio, structural similarity, and feature similarity (P < .001 for all). Opt-SYNb1500 resulted in significantly better image quality (P ≤ .001 for all) and a higher mean area under the curve than ACQb1500 and CALb1500 (P ≤ .042 for all). CONCLUSION: A deep learning framework based on GAN is a promising method to synthesize realistic high-b-value DWI sets with good image quality and accuracy in prostate cancer detection.Keywords: Prostate Cancer, Abdomen/GI, Diffusion-weighted Imaging, Deep Learning Framework, High b Value, Generative Adversarial Networks© RSNA, 2021 Supplemental material is available for this article.

Novel role of Snail 1 in promoting tumor neoangiogenesis.

Snail1 plays an important role in epithelial to mesenchymal transition (EMT) during tumor metastasis; however, whether Snai1 potentiates the process of neoangiogenesis is completely unknown. In the present study, tube formation assay was used to evaluate neoangiogenesis in vitro The expression of Snai1 and other pro-neoangiogenic factors was measured by quantitative real time PCR. Tumor derived endothelial cells (TDECs) were stimulated with fibroblast growth factor 1 (FGF1) or VEGF and formed more tubes compared with untreated, whereas cells treated with Sulforaphane had less tube formation. Silencing SNAI1 significantly attenuated tube formation accompanied by decreased CD31, CD34, and VWF expression in TDECs compared with control. In contrast, overexpression of Snai1 led to more CD31, CD34, and VWF expression and tube formation. To determine if the observed effects of SNAI1 on tube formation was a global phenomenon, the same assay was conducted in normal mesenchymal stem cells (MSCs). SNAI1 silencing did not have any effect on tube formation in MSCs. The expression of TIMP2, ENG, and HIF1A was up-regulated 3-fold or higher after silencing SNAI1, and ID1, VEGFA, PLG, LECT1, HPSE were shown down-regulated. Taken together, our study elucidates an important role of EMT inducer Snai1 in regulating tumor neoangiogenesis, suggesting a potential therapeutic target for overcoming tumor EMT.

[Construction of Lentiviral Vector Over-Expressing MEG3 and Its Effect on XG-7 Cell Apoptosis].

OBJECTIVE: To construct a recombinant lentiviral expression vectors carrying MEG3 and to evaluate its effects on XG-7 cell apoptosis. METHODS: A full-length genomic fragment of human MEG3 was cloned from the pcDNA3.0-MEG3 packaging plasmid and was amplified by PCR. New restriction sites were introduced to be blunted with T4 DNA Ligase. The sequence of the amplified segments was sub-cloned into lentivirus expression vector pCDH-EF1-MCS-T2A-copGFP.The recombined lentiviral expression vector was transfected into 293T cells. FACS was used to detect the effect of MEG3 on XG-7 cell apoptosis after being infected by optimized MOI. RESULTS: The recombined lentiviral expression vector pCDH-EF1-MEG3-copGFP was constructed successfully. The results showed that pCDH-EF1-MEG3-copGFP could increase the mRNA expression of MEG3 dramatically, its transfection efficiency was more than 90%. The apoptosis rate in XG-7 cells (26.8±2.8%) was very significantly higher than that of the control group (P<0.01). CONCLUSION: The recombined lentiviral LncRNA expression vector targeting MEG3, pCDH-EF1-MEG3-copGFP, has been successfully constructed, the pCDH-EF1-MEG3-copGFP can induce the cell apoptosis in human myeloma cell lines. This study set up a basis to further explore the relationship between human myeloma cells and LncRNA-MEG3 gene.

SIRT1 mediates Sphk1/S1P-induced proliferation and migration of endothelial cells.

Angiogenesis is one of the most important components of embryonic organ formation and vessel growth after birth. Sphingosine kinase 1 (Sphk1) and S1P has been confirmed to participate in various cell signaling pathways and physiological processes including neovascularisation. However, the mechanisms that Sphk1/S1P regulates neovascularisation remain unclear. In this study, we elucidated that Sphk1/S1P upregulates sirtuin 1 (SIRT1), a NAD+ dependent deacetylases protease which exerts multiple cellular functions, to regulate the proliferation and migration of endothelial cells. By using CCK8 and Transwell assays, we demonstrated that Sphk1 and SIRT1 knockdown could significantly decrease proliferation and migration of HUVEC cells. Sphk1 inhibition results in SIRT1 downregulation which could be reversed by exogenous S1P in HUVEC cells. Treatment of HUVECs with S1P reverses the impaired proliferation and migration caused by SIRT1 knockdown. Furthermore, Sphk1 knockdown inhibits the phosphorylation of P38 MAPK, ERK and AKT. Treatment of HUVECs with PD98059, SB203580 and Wortmannin, which are the inhibitors of ERK, P38 MAPK and AKT respectively, resulted in decreased SIRT1 expression and reduced migration of HUVEC cells. Thus, we conclude that Sphk1/S1P induces SIRT1 upregulation through multiple pathways including P38 MAPK, ERK and AKT signals. This is the first report to disclose the existence and roles of Sphk1/S1P/SIRT1 axis in regulation of endothelial cell proliferation and migration, which may provide a theoretical basis for angiogenesis.

Hepatocyte growth factor enhances the inflammation-alleviating effect of umbilical cord-derived mesenchymal stromal cells in a bronchiolitis obliterans model.

BACKGROUND AIMS: Specific and effective therapy for prevention or reversal of bronchiolitis obliterans (BO) is lacking. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF) gene modified mesenchymal stromal cells (MSCs) on BO. METHODS: A mouse model of experimental BO was established by subcutaneously transplanting the tracheas from C57BL/6 mice into Balb/C recipients, which were then administered saline, Ad-HGF-modified human umbilical cord-MSCs (MSCs-HGF) or Ad-Null-modified MSCs (MSCs-Null). The therapeutic effects of MSCs-Null and MSCs-HGF were evaluated by using fluorescence-activated cell sorting (FACS) for lymphocyte immunophenotype of spleen, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (rt-PCR) for cytokine expression, and histopathological analysis for the transplanted trachea. RESULTS: The histopathologic recovery of allograft tracheas was improved significantly after MSCs-Null and MSCs-HGF treatment and the beneficial effects were particularly observed in MSCs-HGF-treated mice. Furthermore, the allo-transplantation-induced immunophenotype disorders of the spleen, including regulatory T (Treg), T helper (Th)1, Th2 and Th17, were attenuated in both cell-treated groups. MSCs-HGF treatment reduced expression and secretion of inflammation cytokines interferon-gamma (IFN-γ), and increased expression of anti-inflammatory cytokine interleukin (IL)-4 and IL-10. It also decreased the expression level of the profibrosis factor transforming growth factor (TGF)-ß. CONCLUSION: Treatment of BO with HGF gene modified MSCs results in reduction of local inflammation and promotion in recovery of allograft trachea histopathology. These findings might provide an effective therapeutic strategy for BO.

HGF Gene Modification in Mesenchymal Stem Cells Reduces Radiation-Induced Intestinal Injury by Modulating Immunity.

BACKGROUND: Effective therapeutic strategies to address intestinal complications after radiation exposure are currently lacking. Mesenchymal stem cells (MSCs), which display the ability to repair the injured intestine, have been considered as delivery vehicles for repair genes. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF)-gene-modified MSCs on radiation-induced intestinal injury (RIII). METHODS: Female 6- to 8-week-old mice were radiated locally at the abdomen with a single 13-Gy dose of radiation and then treated with saline control, Ad-HGF or Ad-Null-modified MSCs therapy. The transient engraftment of human MSCs was detected via real-time PCR and immunostaining. The therapeutic effects of non- and HGF-modified MSCs were evaluated via FACS to determine the lymphocyte immunophenotypes; via ELISA to measure cytokine expression; via immunostaining to determine tight junction protein expression; via PCNA staining to examine intestinal epithelial cell proliferation; and via TUNEL staining to detect intestinal epithelial cell apoptosis. RESULTS: The histopathological recovery of the radiation-injured intestine was significantly enhanced following non- or HGF-modified MSCs treatment. Importantly, the radiation-induced immunophenotypic disorders of the mesenteric lymph nodes and Peyer's patches were attenuated in both MSCs-treated groups. Treatment with HGF-modified MSCs reduced the expression and secretion of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α) and interferon-gamma (IFN-γ), increased the expression of the anti-inflammatory cytokine IL-10 and the tight junction protein ZO-1, and promoted the proliferation and reduced the apoptosis of intestinal epithelial cells. CONCLUSIONS: Treatment of RIII with HGF-gene-modified MSCs reduces local inflammation and promotes the recovery of small intestinal histopathology in a mouse model. These findings might provide an effective therapeutic strategy for RIII.

[Effect of anxin granules combined with tirofiba on patients with acute myocardial infarction after elective percutaneous coronary intervention].

To investigate the influence of Anxin granules combined with tirofiban on acute myocardial infarction (AMI) Patients after elective percutaneous coronary intervention (PCI). One hundred and twenty AMI patients were randomly divided into treatment group and control group. The patients in the two groups were all given Tirofiban 30mins before PCI . The treatment group was added Anxin granules 30 mins before and after PCI. Tissue factor (TF) and von willebrand factor (vWF) were tested at 6 hours after operation. Syndromatology alteration of traditional Chinese medicine (TCM) and bleeding complications were observed at 4 weeks after operation. Both TF and vWF at 6 hours after operation of the treatment group was lower than the control group significantly (P < 0.01), while the condition of myocardial ischemia at 90 mins after operation of the treatment group was better than control group with significance. The syndromatology alteration of TCM especially spontaneous perspiration and hypodynamia of the treatment group were improved significantly compared to control group 4 weeks after operation. All patients in both groups had no bleeding complications and thrombopenia. The study suggests that Anxin granules combined with tirofiba can improve the clinical efficacy and the endothelial function of AMI patients after PCI with no increase in bleeding events.

Overexpression of microRNA-29b induces apoptosis of multiple myeloma cells through down regulating Mcl-1.

MicroRNAs (miRNAs) are small, noncoding ribonucleic acids (ncRNAs), which regulate gene expression by targeting mRNAs for translational repression and degradation. Several lines of evidences have indicated that miRNAs act as tumor suppressors and oncogenes. However, the role of miRNAs in pathogenesis of multiple myeloma (MM) remains unclear. In this study, we examined the profile of miRNA expression of primary MM cells, using miRNA microarray and quantitative real-time polymerase chain reaction (qPCR) techniques. These results showed that in the bone marrow specimens analyzed, miRNA-29b was significantly downregulated. Similar results were also observed in human myeloma cell lines (HMCLs). Adenovirus-mediated overexpression of miR-29b induced apoptosis and elevated caspase-3 activation in HMCLs. Using a bioinformatics approach, we found a perfect complementarity between miRNA-29b and the 3'UTR of myeloid-cell-leukemia 1(Mcl-1). It is further confirmed that miRNA-29b downregulated the level of Mcl-1 without effect on the mRNA level using both qRT-PCR assays and Western blot analyses. Moreover, we observed that enforced miR-29b expression by using a retarget miRNA-29b expression vector (Ad5F11p-miR-29b) could induce apoptosis and elevate caspase-3 activation in HMCLs. Our results also indicated that miRNA-29b-induced apoptosis acted antagonistically with IL-6 in HMCLs. These findings suggest that miRNA-29b may play an important role in MM as a tumor suppressor.

[The Mie scattering lidar return signal denoising research based on EMD-DISPO].

Lidar echo signal is a typical non-steady-state, non-stationary signal, and difficult to be dealt with by the traditional filtering methods. As a new signal processing theory proposed in recent years, empirical mode decomposition method can adaptively divide the lidar echo signal into different intrinsic mode function (IMF) components according to different time scale, and noise mainly concentrates in the high-frequency component. However, when filtered with simply removing high frequency component, the useful signal will be possibly reduced. In the present paper, a new method which combines empirical mode decomposition (EMD) with Savitzky-Golay filter is proposed. With experiments, it is indicated that our approach not only removes the noise component effectively but also maintains the useful signal, then will improve the accuracy in the next phase of data processing.

[Development of the human/rat chimera model with neonatal rats].

The purpose of this study was to transplant neonatal rat with human cord blood Lin(-) cells to test the possibility of this xenograft model. The Lin(-) cells were purified from human cord blood (CB) using negative selection strategy based on different lineage-specific antigens. The Lin(-) cells were injected into the liver of neonatal rats using a microinjector at an average of 5 x 10(5) cells for each. Peripheral blood (PB) and spleen were collected at 2,4 and 8 weeks after injection. Flow cytometry was performed to detect human cells in the rat PB, PCR was used to detect human cells in PB as well as spleen. The results showed that a definite proportion of human cells existed in peripheral blood of chimeric rat and the human specific beta2 microglobulin gene fragments were detected in spleen genomic DNA of chimeric rat. It is concluded that human/rat chimera model can be developed with neonatal rats. Human/rat xenograft model may provide a useful and convenient method for human hematopoietic stem cell assay in vivo.