FOXP3 promote the progression of glioblastoma via inhibiting ferroptosis mediated by linc00857/miR-1290/GPX4 axis.

The oncogenic properties of members belonging to the forkhead box (FOX) family have been extensively documented in different types of cancers. In this study, our objective was to investigate the impact of FOXP3 on glioblastoma multiforme (GBM) cells. By conducting a screen using a small hairpin RNA (shRNA) library, we discovered a significant association between FOXP3 and ferroptosis in GBM cells. Furthermore, we observed elevated levels of FOXP3 in both GBM tissues and cell lines, which correlated with a poorer prognosis. FOXP3 was found to promote the proliferation of GBM cells by inhibiting cell ferroptosis in vitro and in vivo. Mechanistically, FOXP3 not only directly upregulated the transcription of GPX4, but also attenuated the degradation of GPX4 mRNA through the linc00857/miR-1290 axis, thereby suppressing ferroptosis and promoting proliferation. Additionally, the FOXP3 inhibitor epirubicin exhibited the ability to impede proliferation and induce ferroptosis in GBM cells both in vitro and in vivo. In summary, our study provided evidences that FOXP3 facilitates the progression of glioblastoma by inhibiting ferroptosis via the linc00857/miR-1290/GPX4 axis, highlighting FOXP3 as a potential therapeutic target for GBM.

Cynaroside Induces G1 Cell Cycle Arrest by Downregulating Cell Division Cycle 25A in Colorectal Cancer.

Natural chemicals derived from herbal plants have recently been recognized as potentially useful treatment alternatives owing to their ability to target a wide range of important biological molecules. Cynaroside is one of these natural compounds with promising anticancer activity for numerous tumor types. Nevertheless, the anticancer effects and molecular mechanisms of action of cynaroside on colorectal cancer (CRC) remain unclear. In this study, cynaroside was found to markedly inhibit CRC cell proliferation and colony formation in vitro. Cynaroside also inhibited cell proliferation in vivo and decreased the expression of KI67, a cell nuclear antigen. RNA sequencing revealed 144 differentially expressed genes (DEGs) in HCT116 cells and 493 DEGs in RKO cells that were enriched in the cell cycle signaling pathway. Cell division cycle 25A (CDC25A), a DEG widely enriched in the cell cycle signaling pathway, is considered a key target of cynaroside in CRC cells. Cynaroside also inhibited DNA replication and arrested cells in the G1/S phase in vitro. The expression levels of CDC25A and related G1-phase proteins were significantly elevated after CDC25A overexpression in CRC cells, which partially reversed the inhibitory effect of cynaroside on CRC cell proliferation and G1/S-phase arrest. In summary, cynaroside may be used to treat CRC as it inhibits CDC25A expression.

Predicting the prognosis of glioma patients with TERT promoter mutations and guiding the specific immune profile of immune checkpoint blockade therapy.

The telomerase reverse transcriptase promoter (TERTp) is frequently mutated in gliomas. This study sought to identify immune biomarkers of gliomas with TERTp mutations. Data from TCGA were used to identify and validate survival-associated gene signatures, and immune and stromal scores were calculated using the ESTIMATE algorithm. High stromal or immune scores in patients with TERTp-mutant gliomas correlated with shorter overall survival compared to cases with low stromal or immune scores. Among TERTp-mutant gliomas with both high immune and high stromal scores, 213 commonly shared DEGs were identified. Among 71 interacting DEGs representing candidate hub genes in a PPI network, HOXC6, WT1, CD70, and OTP showed significant ability in establishing subgroups of high- and low-risk patients. A risk model based on these 4 genes showed strong prognostic potential for gliomas with mutated TERTp, but was inapplicable for TERTp-wild-type gliomas. TERTp-mutant gliomas with high-risk scores displayed a greater percentage of naïve B cells, plasma cells, naïve CD4 T cells, and activated mast cells than low-risk score gliomas. TIDE analysis indicated that immune checkpoint blockade (ICB) therapy may benefit glioma patients with TERTp mutations. The present risk model can help predict prognosis of glioma patients with TERTp mutations and aid ICB treatment options.

Gastrodin Induces Ferroptosis of Glioma Cells via Upregulation of Homeobox D10.

Gastrodin, the primary bioactive compound found in Gastrodia elata, has been shown to exhibit neuroprotective properties in a range of neurological disorders. However, the precise mechanisms through which gastrodin influences glioma cells remain unclear, and there is a scarcity of data regarding its specific effects. To ascertain the viability of glioma cell lines LN229, U251, and T98, the CCK-8 assay, a colony formation assay, and a 3D culture model were employed, utilizing varying concentrations of gastrodin (0, 5, 10, and 20 µM). Gastrodin exhibited a notable inhibitory effect on the growth of glioma cells, as evidenced by its ability to suppress colony formation and spheroid formation. Additionally, gastrodin induced ferroptosis in glioma cells, as it can increase the levels of reactive oxygen species (ROS) and peroxidized lipids, and reduced the levels of glutathione. Using a subcutaneous tumor model, gastrodin was found to significantly inhibit the growth of the T98 glioma cell line in vivo. Using high-throughput sequencing, PPI analysis, and RT-qPCR, we successfully identified Homeobox D10 (HOXD10) as the principal target of gastrodin. Gastrodin administration significantly enhanced the expression of HOXD10 in glioma cells. Furthermore, treatment with gastrodin facilitated the transcription of ACSL4 via HOXD10. Notably, the inhibition of HOXD10 expression impeded ferroptosis in the cells, which was subsequently restored upon rescue with gastrodin treatment. Overall, our findings suggest that gastrodin acts as an anti-cancer agent by inducing ferroptosis and inhibiting cell proliferation in HOXD10/ACSL4-dependent pathways. As a prospective treatment for gliomas, gastrodin will hopefully be effective.

Identification and optimization of peptide inhibitors to block VISTA/PSGL-1 interaction for cancer immunotherapy.

Developing new therapeutic agents for cancer immunotherapy is highly demanding due to the low response ratio of PD-1/PD-L1 blockade in cancer patients. Here, we discovered that the novel immune checkpoint VISTA is highly expressed on a variety of tumor-infiltrating immune cells, especially myeloid derived suppressor cells (MDSCs) and CD8+ T cells. Then, peptide C1 with binding affinity to VISTA was developed by phage displayed bio-panning technique, and its mutant peptide VS3 was obtained by molecular docking based mutation. Peptide VS3 could bind VISTA with high affinity and block its interaction with ligand PSGL-1 under acidic condition, and elicit anti-tumor activity in vivo. The peptide DVS3-Pal was further designed by d-amino acid substitution and fatty acid modification, which exhibited strong proteolytic stability and significant anti-tumor activity through enhancing CD8+ T cell function and decreasing MDSCs infiltration. This is the first study to develop peptides to block VISTA/PSGL-1 interaction, which could act as promising candidates for cancer immunotherapy.

5'-tRF-19-Q1Q89PJZ Suppresses the Proliferation and Metastasis of Pancreatic Cancer Cells via Regulating Hexokinase 1-Mediated Glycolysis.

tRNA-derived small RNAs (tDRs) are dysregulated in several diseases, including pancreatic cancer (PC). However, only a limited number of tDRs involved in PC progression are known. Herein, a novel tDR, 5'-tRF-19-Q1Q89PJZ (tRF-19-Q1Q89PJZ), was verified in PC plasma using RNA and Sanger sequencing. tRF-19-Q1Q89PJZ was downregulated in PC tissues and plasma, which was related to advanced clinical characteristics and poor prognosis. tRF-19-Q1Q89PJZ overexpression inhibited the malignant activity of PC cells in vitro, while tRF-19-Q1Q89PJZ inhibition produced an opposite effect. The differentially expressed genes induced by tRF-19-Q1Q89PJZ overexpression were enriched in "pathways in cancer" and "glycolysis". Mechanistically, tRF-19-Q1Q89PJZ directly sponged hexokinase 1 (HK1) mRNA and inhibited its expression, thereby suppressing glycolysis in PC cells. HK1 restoration relieved the inhibitory effect of tRF-19-Q1Q89PJZ on glycolysis in PC cells and on their proliferation and mobility in vitro. tRF-19-Q1Q89PJZ upregulation inhibited PC cell proliferation and metastasis in vivo and suppressed HK1 expression in tumor tissues. Furthermore, tRF-19-Q1Q89PJZ expression was attenuated under hypoxia. Collectively, these findings indicate that tRF-19-Q1Q89PJZ suppresses the malignant activity of PC cells by regulating HK1-mediated glycolysis. Thus, tRF-19-Q1Q89PJZ may serve as a key target for PC therapy.

An immune signature to predict the prognosis of ATRX-wildtype glioma patients and guide immune checkpoint blockade therapy.

Immune and stromal cells contribute to glioma progression by infiltrating the tumor microenvironment. We used clinical characteristics, RNA sequencing data and the ESTIMATE algorithm to obtain stromal and immune scores for alpha thalassemia retardation syndrome X-linked (ATRX)-mutation-type (ATRX-mt) and ATRX-wildtype (ATRX-wt) glioma tissues from The Cancer Genome Atlas. To identify specific immune biomarkers of glioma, we compared the gene expression profiles of ATRX-wt glioma tissues with high vs. low immune/stromal scores, and discovered 162 differentially expressed genes. The protein-protein interaction network based on these results contained 80 interacting genes, of which seven (HOXA5, PTPN2, WT1, HOXD10, POSTN, ADAMDEC1 and MYBPH) were identified as key prognostic genes via LASSO and Cox regression analyses. A risk model constructed using the expression of these seven genes could predict survival for ATRX-wt glioma patients, but was ineffective for ATRX-mt patients. T cells and macrophages were more prevalent in low-risk than in high-risk glioma tissues. Immune checkpoint blockade treatment was highly beneficial for patients with low risk scores. High-risk gliomas were predicted to be more sensitive to rapamycin, dasatinib, 5-fluorouracil and gemcitabine. Thus, our model can be used for the diagnosis, prognostic prediction and treatment planning of ATRX-wt glioma patients.

Biophysical investigation of interactions between SARS-CoV-2 spike protein and neuropilin-1.

Recent studies have suggested that neuropilin-1 (NRP1) may serve as a potential receptor in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the biophysical characteristics of interactions between NRP1 and SARS-CoV-2 remain unclear. In this study, we examined the interactions between NRP1 and various SARS-CoV-2 spike (S) fragments, including the receptor-binding domain (RBD) and the S protein trimer in a soluble form or expressed on pseudovirions, using atomic force microscopy and structural modeling. Our measurements shows that NRP1 interacts with the RBD and trimer at a higher binding frequency (BF) compared to ACE2. This NRP1-RBD interaction has also been predicted and simulated via AlphaFold2 and molecular dynamics simulations, and the results indicate that their binding patterns are very similar to RBD-ACE2 interactions. Additionally, under similar loading rates, the most probable unbinding forces between NRP1 and S trimer (both soluble form and on pseudovirions) are larger than the forces between NRP1 and RBD and between trimer and ACE2. Further analysis indicates that NRP1 has a stronger binding affinity to the SARS-CoV-2 S trimer with a dissociation rate of 0.87 s-1 , four times lower than the dissociation rate of 3.65 s-1 between NRP1 and RBD. Moreover, additional experiments show that RBD-neutralizing antibodies can significantly reduce the BF for both ACE2 and NRP1. Together, the study suggests that NRP1 can be an alternative receptor for SARS-CoV-2 attachment to human cells, and the neutralizing antibodies targeting SARS-CoV-2 RBD can reduce the binding between SARS-CoV-2 and NRP1.

Ar-turmerone inhibits the proliferation and mobility of glioma by downregulating cathepsin B.

Ar-turmerone, a compound isolated from turmeric seeds, has exhibited anti-malignant, anti-aging and anti-inflammatory properties. Here, we assessed the effects of ar-turmerone on glioma cells. U251, U87 and LN229 glioma cell lines were treated with different concentrations of ar-turmerone (0, 50, 100 and 200 µM), and their viability and mobility were evaluated using Cell Counting Kit 8, colony formation, wound healing and Transwell assays. The effects of ar-turmerone on U251 glioma cell proliferation were also assessed using a subcutaneous implantation tumor model. High-throughput sequencing, bioinformatic analyses and quantitative real-time polymerase chain reactions were used to identify the key signaling pathways and targets of ar-turmerone. Ar-turmerone reduced the proliferation rate and mobility of glioma cells in vitro and arrested cell division at G1/S phase. Cathepsin B was identified as a key target of ar-turmerone in glioma cells. Ar-turmerone treatment reduced cathepsin B expression and inhibited the cleavage of its target protein P27 in glioma cells. On the other hand, cathepsin B overexpression reversed the inhibitory effects of ar-turmerone on glioma cell proliferation, mobility progression in vitro and in vivo. In conclusion, ar-turmerone suppressed cathepsin B expression and P27 cleavage, thereby inhibiting the proliferation and mobility of glioma cells.

Knockdown of FUT11 inhibits the progression of gastric cancer via the PI3K/AKT pathway.

Gastric cancer (GC) is a common and highly malignant tumor of the digestive tract. Members of the focused fucosyltransferase (FUT) family participate in the advancement of various types of cancer. However, research of FUT family members in the progression of GC known to be limited. The purpose of the research was to determine the function of important affiliates of the FUT family in GC and to explore its impacts on the proliferation and migration of GC cells and molecular mechanisms. For the study, fucosyltransferase11 (FUT11) was confirmed to be the only affiliate of the FUT family that was upmodulated in GC tissues and linked to poor survival according to GEPIA data. Furthermore, compared with adjacent noncancerous tissues, the expression of FUT11 was increased in GC tissues. The elevated FUT11 expression suggested that the overall survival (OS) rate of GC is low. Inhibition of FUT11 significantly reduced the proliferation and migration and suppressed the PI3K/AKT pathway by down-regulated collagen type VI alpha 3 chain (COL6A3) in GC cells. The present study has demonstrated that reinstating the expression of COL6A3 in gastric cancer (GC) cells can counteract the inhibitory impact of FUT11 knockdown on the proliferation and migration of GC cells. In conclusion, FUT11 may serve as a novel biomarker for GC, as it modulates GC cell proliferation and migration through the PI3K/AKT signaling pathway.

Pancreatic stellate cell-derived exosomal tRF-19-PNR8YPJZ promotes proliferation and mobility of pancreatic cancer through AXIN2.

The pancreatic stellate cells (PSCs) play an important role in the development of pancreatic cancer (PC) through mechanisms that remain unclear. Exosomes secreted from PSCs act as mediators for communication in PC. This study aimed to explore the role of PSC-derived exosomal small RNAs derived from tRNAs (tDRs) in PC cells. Exosomes from PSCs were extracted and used to detect their effects on PC cell proliferation, migration and invasion. Exosomal tDRs profiling was performed to identify PSC-derived exosomal tDRs. ISH and qRT-PCR were used to examine the tRF-19-PNR8YPJZ levels and clinical value in clinical samples. The biological function of exosomal tRF-19-PNR8YPJZ was determined using the CCK-8, clone formation, wound healing and transwell assays, subcutaneous tumour formation and lung metastatic models. The relationship between the selected exosomal tRF-19-PNR8YPJZ and AXIN2 was determined by RNA sequencing, luciferase reporter assay. PSC-derived exosomes promoted the proliferation, migration, and invasion of PC cells. Novel and abundant tDRs are found to be differentially expressed in PANC-1 cells after treatment with PSC-derived exosomes, such as tRF-19-PNR8YPJZ. PC tissue samples showed markedly higher levels of tRF-19-PNR8YPJZ than normal controls. Patients with PC exhibiting high tRF-19-PNR8YPJZ expression had a highly lymph node invasion, metastasis, perineural invasion, advanced clinical stage and poor overall survival. Exosomal tRF-19-PNR8YPJZ from PSCs targeted AXIN2 in PC cells and decreased its expression, thus activating the Wnt pathway and promoting proliferation and metastasis. Exosomal tRF-19-PNR8YPJZ from PSCs promoted proliferation and metastasis in PC cells via AXIN2.

Terpinen-4-ol Induces Ferroptosis of Glioma Cells via Downregulating JUN Proto-Oncogene.

According to previous research, turmeric seeds exhibit anti-inflammatory, anti-malignancy, and anti-aging properties due to an abundance of terpinen-4-ol (T4O). Although it is still unclear how T4O works on glioma cells, limited data exist regarding its specific effects. In order to determine whether or not glioma cell lines U251, U87, and LN229 are viable, CCK8 was used as an assay and a colony formation assay was performed using different concentrations of T4O (0, 1, 2, and 4 µM). The effect of T4O on the proliferation of glioma cell line U251 was detected through the subcutaneous implantation of the tumor model. Through high-throughput sequencing, a bioinformatic analysis, and real-time quantitative polymerase chain reactions, we identified the key signaling pathways and targets of T4O. Finally, for the measurement of the cellular ferroptosis levels, we examined the relationship between T4O, ferroptosis, and JUN and the malignant biological properties of glioma cells. T4O significantly inhibited glioma cell growth and colony formation and induced ferroptosis in the glioma cells. T4O inhibited the subcutaneous tumor proliferation of the glioma cells in vivo. T4O suppressed JUN transcription and significantly reduced its expression in the glioma cells. The T4O treatment inhibited GPX4 transcription through JUN. The overexpression of JUN suppressed ferroptosis in the cells rescued through T4O treatment. Taken together, our data suggest that the natural product T4O exerts its anti-cancer effects by inducing JUN/GPX4-dependent ferroptosis and inhibiting cell proliferation, and T4O will hope-fully serve as a prospective compound for glioma treatment.

An inflammation-associated ferroptosis signature optimizes the diagnosis, prognosis evaluation and immunotherapy options in hepatocellular carcinoma.

Inflammation and ferroptosis crosstalk complexly with immune microenvironment of hepatocellular carcinoma (HCC), thus affecting the efficacy of immunotherapy. Herein, our aim was to identify the inflammation-associated ferroptosis (IAF) biomarkers for contributing HCC. A total of 224 intersecting DEGs identified from different inflammation- and ferroptosis-subtypes were set as IAF genes. Seven of them including ADH4, APOA5, CFHR3, CXCL8, FTCD, G6PD and PON1 were used for construction of a risk model which classified HCC patients into two groups (high and low risk). HCC patients in the high-risk group exhibited shorter survival rate and higher immune score, and were predicted to have higher respond rate in immune checkpoint inhibition (ICI) therapy. Levels of the seven genes were significantly changed in HCC tissues in comparison to adjacent tissues. After inserting the gene expression into the risk model, we found that the risk model exhibited the higher diagnostic value for distinguish HCC tissues compared each single gene. Furthermore, HCC tissues from our research group with high-risk score exhibited more cases of microsatellite instability (MSI), heavier tumour mutational burden (TMB), higher expression level of PDL1 and cells with CD8. Knockdown of APOA5 reduced HCC cell proliferation combining with elevating inflammation and ferroptosis levels. In conclusion, we considered APOA5 maybe a novel target for suppressing HCC via simultaneously elevating inflammation and ferroptosis levels, and signature constructed by seven IAF genes including ADH4, APOA5, CFHR3, CXCL8, FTCD, G6PD and PON1 can act as a biomarker for optimising the diagnosis, prognosis evaluation and immunotherapy options in HCC patients.

JUND/linc00976 promotes cholangiocarcinoma progression and metastasis, inhibits ferroptosis by regulating the miR-3202/GPX4 axis.

Long noncoding RNAs (lncRNAs) are a novel class of noncoding RNAs that have emerged as critical regulators and biomarkers in various cancers. Nevertheless, the expression profile and mechanistic function of lncRNAs in cholangiocarcinoma (CCA) remain unclear. Herein, we examined the expression levels of linc00976 in clinical specimens and cell lines using reverse transcription-quantitative PCR. In total, 50 patients with CCA were enrolled to analyze the correlation between linc00976 expression and clinical characteristics of CCA. Loss- and gain-of-function experiments were performed to investigate the biological effects of linc00976 on proliferation, ferroptosis, migration, and invasion of CCA cells in vitro and in vivo. In situ hybridization, RNA immunoprecipitation, bioinformatic databases, RNA pull-down assay, a dual-luciferase reporter assay, mRNA sequencing, chromatin immunoprecipitation-PCR, and rescue experiments were performed to elucidate the underlying mechanisms of linc00976-induced competitive endogenous RNA regulatory networks. We characterized a novel and abundant lncRNA, linc00976, that functions as a pro-oncogenic regulator of CCA progression. Compared with normal controls, linc00976 was dramatically upregulated in CCA tissue samples and cell lines. Patients with CCA exhibiting high linc00976 expression had a highly advanced clinical stage, substantial lymph node metastasis, and poor overall survival. Knockdown of linc00976 significantly repressed proliferation and metastasis and promoted ferroptosis of CCA cells both in vitro and in vivo, whereas linc00976 overexpression exerted the opposite effect. Mechanistically, linc00976 competitively interacted with miR-3202 to upregulate GPX4 expression, thus contributing to the malignant biological behavior of CCA cells. Moreover, we demonstrated that JUND specifically interacts with the linc00976 promoter and activates linc00976 transcription. Accordingly, JUND promotes linc00976 transcription, and linc00976 plays a crucial role in accelerating CCA tumorigenesis and metastasis and inhibiting ferroptosis by modulating the miR-3202/GPX4 axis. These findings suggest that targeting linc00976 may afford a promising therapeutic strategy for patients with CCA.

Transformer 2 alpha homolog is a downstream gene of hypoxia-inducible factor 1 subunit alpha and is involved in the progression of pancreatic cancer.

Intratumoral hypoxia is a common feature of pancreatic cancer (PC) and also plays a role in its progression. However, hypoxia-regulated signatures in PC are still not completely understood. This study aimed to identify core hypoxia-associated genes and determine their underlying molecular mechanisms in PC cells. Transformer 2 alpha homolog (TRA2A) was found to be an important hypoxia-associated gene, which was upregulated in PC tissues and in PC cells cultured under hypoxia. High TRA2A expression was associated with advanced stage, poor differentiation, and lymph node metastasis. Under normoxic and hypoxic conditions, knockdown of TRA2A both markedly suppressed PC cell proliferation and motility in vitro and in vivo, as well as activation of the AKT pathway. Hypoxia-inducible factor 1 subunit alpha (HIF1α) upregulated the transcription of TRA2A by directly binding to its promoter. TRA2A showed a co-expression relationship with HIF1α in PC tissues. Overexpression of TRA2A alleviated the pro-inhibitive functions of HIF1α-inhibition on PC cell proliferation and motility under hypoxia. In conclusion, TRA2A is a crucial downstream gene of HIF1α that accelerates the proliferation and motility of PC cells. TRA2A may be a novel and practical molecular target for investigating the hypoxic response of PC cells.Abbreviations: TRA2A, transformer 2A protein; PC, pancreatic cancer; HIF1α, hypoxia-inducible factor 1-alpha; GEO, Gene Expression Omnibus; IHC, immunohistochemical staining.

Long noncoding RNA LINC00857 promotes pancreatic cancer proliferation and metastasis by regulating the miR-130b/RHOA axis.

Dysregulation of long noncoding RNAs (lncRNAs) is involved in the pathogenesis and progression of pancreatic cancer (PC). In the current study, we investigated the role and molecular mechanism of LINC00857 in PC. The expression of LINC00857 in PC was analyzed by bioinformatics analysis and qRT-PCR, and the relationship between LINC00857 expression and clinical characteristics of patients of PC was analyzed by Fisher's exact test. Gain- and loss-of-function assays were performed to determine the biological function of LINC00857 in PC. The relationship between LINC00857, miR-130b, and RHOA were determined by RNA pull-down assay, luciferase assay, and qRT-PCR. Our results demonstrated that LINC00857 expression was elevated in PC, and high expression of LINC00857 was positively associated with tumor diameter, T stage, and lymph node metastasis. LINC00857 promoted the proliferation and mobility of PC cells in vitro and in vivo. Mechanistically, LINC00857 acts as a sponge for miR-130b and decreases its expression. miR-130b exhibits tumor suppressor functions in PC, and RHOA was identified as the key target gene of miR-130b. The functions induced by LINC00857 in PC cells were dependent on the miR-130b/RHOA axis. In conclusion, the current study indicated that LINC00857 promotes PC tumorigenesis and metastasis by modulating the miR-130b/RHOA axis, implying that LINC00857 might be a new therapeutic target for PC.

Terpinen-4-ol inhibits the proliferation and mobility of pancreatic cancer cells by downregulating Rho-associated coiled-coil containing protein kinase 2.

Terpinen-4-ol (T4O), a compound isolated from the seeds of turmeric, has exhibited anti-malignancy, anti-aging, and anti-inflammatory properties in previous studies. However, the specific effects and molecular mechanisms of T4O on pancreatic cancer (PC) cells remain largely unknown. In this study, we demonstrated that T4O markedly suppressed PC cell proliferation and colony formation in vitro and induced apoptosis. Similarly, T4O significantly inhibited the migration and invasion of PC cells in vitro. Through RNA sequencing, 858 differentially expressed genes (DEGs) were identified, which were enriched in the Rhodopsin (RHO)/ Ras homolog family member A (RHOA) signaling pathway. Rho-associated coiled-coil containing protein kinase 2 (ROCK2), a DEG enriched in the RHO/RHOA signaling pathway, was considered as a key target of T4O in PC cells; it was significantly reduced after T4O treatment, highly expressed in PC tissues, and negatively associated with patient outcome. Overexpression of ROCK2 significantly reduced the inhibitory effects of T4O on PC cell proliferation and mobility. Moreover, T4O inhibited cell proliferation in vivo and decreased the Ki-67, cell nuclear antigen, EMT markers, and ROCK2 expression. In conclusion, we consider that T4O can suppress the malignant biological behavior of PC by reducing the expression of ROCK2, thus contributing to PC therapy.

Autophagy-associated circRNA circATG7 facilitates autophagy and promotes pancreatic cancer progression.

Dysregulation of autophagy and circular RNAs (circRNAs) are involved in the pancreatic cancer (PC) progression. However, the regulatory network between circRNAs, autophagy, and PC progression remains unknown. Herein, we demonstrated that autophagy-associated circRNA circ-autophagy related 7 (circATG7) was elevated in PC tissues compared to adjacent tissues, and in PC cells treated with EBSS and hypoxia. circATG7 expression was positively associated with tumor diameter and lymph node invasion in patients with PC. circATG7 overexpression promoted PC cell proliferation, mobility, and autophagy in vitro, while circATG7 knockdown induced the opposite effects. ATG7 inhibition attenuated the effects of circATG7 on the biological functions of PC cells. CircATG7 is located in the cell cytoplasm and nucleus. Cytoplasmic circATG7 sponged miR-766-5p and decreased its expression, and increased the expression of ATG7, a target gene of miR-766-5p. Nuclear circATG7 acted as a scaffold to increase the interaction between the human antigen R protein and ATG7 mRNA and enhanced ATG mRNA stability. Furthermore, we demonstrated that circATG7 regulates PC cell proliferation and metastasis in vivo via ATG7-dependent autophagy. In conclusion, our results demonstrated that circATG7 accelerates PC progression via miR-766-5p/ATG7 and that HUR/ATG7 depends on autophagic flux. Thus, circATG7 may be a potential therapeutic target for PC.

Desialylation of O-glycans activates von Willebrand factor by destabilizing its autoinhibitory module.

BACKGROUND: The binding of the A1 domain of von Willebrand factor (VWF) to platelet receptor glycoprotein (GP)Ibα defines the VWF activity in hemostasis. Recent studies suggest that sequences flanking A1 form cooperatively an autoinhibitory module (AIM) that reduces the accessibility of the GPIbα binding site on A1. Application of a tensile force induces unfolding of the AIM. Desialylation induces spontaneous binding of plasma VWF to platelets. Most O-glycans in VWF are located around the A1 domain. Removing certain O-glycans in the flanking sequences by site-directed mutagenesis enhances A1 binding to GPIbα and produces an effect similar to type 2B von Willebrand disease in animals. OBJECTIVES: To understand if and how desialylation of O-glycans in the flanking sequences increases A1 activity. METHODS: A recombinant AIM-A1 fragment encompassing VWF residues 1238-1493 and only O-glycans was treated with neuraminidase to produce desialylated protein. The glycan structure, dynamics, stability, and function of the desialylated protein was characterized by biochemical and biophysical methods and compared to the sialylated fragment. RESULTS: Asialo-AIM-A1 exhibited increased binding activity and induced more apparent platelet aggregation than its sialylated counterpart. It exhibited a lower melting temperature, and increased hydrogen-deuterium exchange rates at residues near the secondary GPIbα binding site and the N-terminal flanking sequence. Asialo-AIM-A1 is less mechanically stable than sialo-AIM-A1, with its unstressed unfolding rate approximately 3-fold greater than the latter. CONCLUSIONS: Desialylation of O-glycans around A1 increases its activity by destabilizing the AIM.

Biophysical characterization of lynx-nicotinic receptor interactions using atomic force microscopy.

Nicotinic acetylcholine receptors (nAChRs) are broadly expressed in the central and peripheral nervous systems, playing essential roles in cholinergic neurotransmission. The lynx family proteins, a subset of the Ly6/uPAR superfamily expressed in multiple brain regions, have been shown to bind to nAChRs and modulate their function via allosteric regulation. The binding interactions between lynx and nAChRs, however, have not been systematically quantified and compared. In this work, we characterized the interactions between lynx1 or lynx2 and α3ß4- or α7-nAChRs using single-molecule atomic force microscopy (AFM). The AFM technique allows the quantification of the off-rate of lynx-nAChR binding and of the energetic barrier width between the bound state and transition state, providing a biophysical means to compare the selectivity of lynx proteins for nAChR subtypes. Results indicate that lynx1 has a marginal preference for α7- over α3ß4-nAChRs. Strikingly, lynx2 exhibits a two order of magnitude stronger affinity for α3ß4- compared to α7-nAChRs. Together, the AFM assay serves as a valuable tool for the biophysical characterization of lynx-nAChR binding affinities. Revealing the differential affinities of lynx proteins for nAChR subtypes will help elucidate how lynx regulates nAChR-dependent functions in the brain, including nicotine addiction and other critical pathways.