Roles and application of exosomes in the development, diagnosis and treatment of gastric cancer.

As important messengers of intercellular communication, exosomes can regulate local and distant cellular communication by transporting specific exosomal contents and can also promote or suppress the development and progression of gastric cancer (GC) by regulating the growth and proliferation of tumor cells, the tumor-related immune response and tumor angiogenesis. Exosomes transport bioactive molecules including DNA, proteins, and RNA (coding and noncoding) from donor cells to recipient cells, causing reprogramming of the target cells. In this review, we will describe how exosomes regulate the cellular immune response, tumor angiogenesis, proliferation and metastasis of GC cells, and the role and mechanism of exosome-based therapy in human cancer. We will also discuss the potential application value of exosomes as biomarkers in the diagnosis and treatment of GC and their relationship with drug resistance.

Qihuang Granule protects the retinal pigment epithelium from oxidative stress via regulation of the alternative complement pathway.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of vision loss in elderly people, and dry AMD is the most common type of AMD. Oxidative stress and alternative complement pathway activation may play essential roles in the pathogenesis of dry AMD. There are no available drugs for dry AMD. Qihuang Granule (QHG) is an herbal formula for the treatment of dry AMD, and it achieves a good clinical effect in our hospital. However, its potential mechanism is unclear. Our study investigated the effects of QHG on oxidative stress-associated retinal damage to reveal its underlying mechanism. METHODS: Oxidative stress models were established using H2O2 and NaIO3 in ARPE-19 cells and C57BL/6 mice. Cell apoptosis and viability were assessed using phase contrast microscopy and flow cytometry, respectively. Alterations in the mouse retinal structure were evaluated using Masson staining and transmission electron microscopy (TEM). The expression of complement factor H (CFH), complement component 3a (C3a) and complement component 5a (C5a) in retinal pigment epithelium (RPE) cells and mice was measured using RT‒PCR, Western blot analysis and ELISA. RESULTS: Pretreatment with QHG significantly prevented cell apoptosis and disorder of the RPE and inner segment/outer segment (IS/OS) in H2O2-treated RPE cells and NaIO3-injected mice. QHG alleviated mitochondrial damage in mouse RPE cells, as shown by TEM. QHG also promoted CFH expression and inhibited the expression of C3a and C5a. CONCLUSIONS: The results suggest that QHG protects the retinal pigment epithelium from oxidative stress, likely by regulating the alternative complement pathway.

Mechanisms and applications of ferroptosis-associated regulators in cancer therapy and drug resistance.

Iron is an essential element for almost all living things. Both iron excess and iron deficiency can damage the body's health, but the body has developed complex mechanisms to regulate iron balance. The imbalance of iron homeostasis and lipid peroxidation are important features of ferroptosis. In this review, we summarize the latest regulatory mechanisms of ferroptosis, the roles of relevant regulators that target ferroptosis for cancer therapy, and their relationship to drug resistance. In conclusion, targeting ferroptosis is an important strategy for cancer therapy.

Targeting UBE2T Potentiates Gemcitabine Efficacy in Pancreatic Cancer by Regulating Pyrimidine Metabolism and Replication Stress.

BACKGROUND & AIMS: Although small patient subsets benefit from current targeted strategies or immunotherapy, gemcitabine remains the first-line drug for pancreatic cancer (PC) treatment. However, gemcitabine resistance is widespread and compromises long-term survival. Here, we identified ubiquitin-conjugating enzyme E2T (UBE2T) as a potential therapeutic target to combat gemcitabine resistance in PC. METHODS: Proteomics and metabolomics were combined to examine the effect of UBE2T on pyrimidine metabolism remodeling. Spontaneous PC mice (LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre; KPC) with Ube2t-conditional knockout, organoids, and large-scale clinical samples were used to determine the effect of UBE2T on gemcitabine efficacy. Organoids, patient-derived xenografts (PDX), and KPC mice were used to examine the efficacy of the combination of a UBE2T inhibitor and gemcitabine. RESULTS: Spontaneous PC mice with Ube2t deletion had a marked survival advantage after gemcitabine treatment, and UBE2T levels were positively correlated with gemcitabine resistance in clinical patients. Mechanistically, UBE2T catalyzes ring finger protein 1 (RING1)-mediated ubiquitination of p53 and relieves the transcriptional repression of ribonucleotide reductase subunits M1 and M2, resulting in unrestrained pyrimidine biosynthesis and alleviation of replication stress. Additionally, high-throughput compound library screening using organoids identified pentagalloylglucose (PGG) as a potent UBE2T inhibitor and gemcitabine sensitizer. The combination of gemcitabine and PGG diminished tumor growth in PDX models and prolonged long-term survival in spontaneous PC mice. CONCLUSIONS: Collectively, UBE2T-mediated p53 degradation confers PC gemcitabine resistance by promoting pyrimidine biosynthesis and alleviating replication stress. This study offers an opportunity to improve PC survival by targeting UBE2T and develop a promising gemcitabine sensitizer in clinical translation setting.

Co-assembled Nanocarriers of De Novo Thiol-Activated Hydrogen Sulfide Donors with an RGDFF Pentapeptide for Targeted Therapy of Non-Small-Cell Lung Cancer.

Hydrogen sulfide releasing agents (or H2S donors) have been recognized gasotransmitters with potent cytoprotective and anticancer properties. However, the clinical application of H2S donors has been hampered by their fast H2S-release, instability, and lack of tumor targeting, despite the unclear molecular mechanism of H2S action. Here we rationally designed an amphiphilic pentapeptide (RGDFF) to coassemble with the de novo designed thiol-activated H2S donors (CL2/3) into nanocarriers for targeted therapy of non-small-cell lung cancer, which has been proved as a one-stone-three-birds strategy. The coassembly approach simply solved the solubility issue of CL2/3 by the introduction of electron-donating groups (phenyl rings) to slow down the H2S release while dramatically improving their biocompatible interface, circulation time, slow release of H2S, and tumor targeting. Experimental results confirmed that as-prepared coassembled nanocarriers can significantly induce the intrinsic apoptotic, effectively arrest cell cycle at the G2/M phase, inhibit H2S-producing enzymes, and lead to mitochondrial dysfunction by increasing intracellular ROS production in H1299 cells. The mouse tumorigenesis experiments further confirmed the in vivo anticancer effects of the coassembled nanocarriers, and such treatment made tumors more sensitive to radiotherapy then improved the prognosis of tumor-bearing mice, which holds great promise for developing a new combined approach for NSCLC.

Therapeutic strategies targeting uPAR potentiate anti-PD-1 efficacy in diffuse-type gastric cancer.

The diffuse-type gastric cancer (DGC) is a subtype of gastric cancer (GC) associated with low HER2 positivity rate and insensitivity to chemotherapy and immune checkpoint inhibitors. Here, we identify urokinase-type plasminogen activator receptor (uPAR) as a potential therapeutic target for DGC. We have developed a novel anti-uPAR monoclonal antibody, which targets the domains II and III of uPAR and blocks the binding of urokinase-type plasminogen activator to uPAR. We show that the combination of anti-uPAR and anti-Programmed cell death protein 1 (PD-1) remarkably inhibits tumor growth and prolongs survival via multiple mechanisms, using cell line-derived xenograft and patient-derived xenograft mouse models. Furthermore, uPAR chimeric antigen receptor-expressing T cells based on the novel anti-uPAR effectively kill DGC patient-derived organoids and exhibit impressive survival benefit in the established mouse models, especially when combined with PD-1 blockade therapy. Our study provides a new possibility of DGC treatment by targeting uPAR in a unique manner.

Structural characterization and hepatoprotective activity of an acidic polysaccharide from Ganoderma lucidum.

In this study, Ganoderma lucidum crude polysaccharide (GLP) was found to have protective effect on liver damage in mice caused by restraint stress through improving oxidative status. Two polysaccharides, including a neutral ß-glucan (GLPB2) and an acidic ß-glucan (GLPC2) were purified from GLP through anion-exchange chromatography (AEC) combined with gel permeation. GLPC2, with an average molecular weight of 20.56 kDa, exhibited stronger hepatoprotective effect against H2O2-induced liver injury in HepG2 cells compared to GLPB2. Glycosidic residues and NMR analysis comprehensively revealed that GLPC2 contained d-Glcp-(1→, →3)-d-Glcp-(1→, →4)-d-Glcp-(1→, →6)-d-Glcp-(1→, →3, 6)-d-Glcp-(1 â†’ and â†’ 4)-d-GlcpA-(1 â†’ . AEC can be an effective technique for separating ß-glucans into neutral and acidic fractions by different ionic strength buffer. The findings provided a theoretical basis for the potential application of G. lucidum polysaccharides as a hepatoprotective in food and pharmaceutical industry.

Improving therapeutic resistance: beginning with targeting the tumor microenvironment.

Cancer is a serious threat to human health and life. The tumor microenvironment (TME) not only plays a key role in the occurrence, development and metastasis of cancer, but also has a profound impact on treatment resistance. To improve and solve this problem, an increasing number of strategies targeting the TME have been proposed, and great progress has been made in recent years. This article reviews the characteristics and functions of the main matrix components of the TME and the mechanisms by which each component affects drug resistance. Furthermore, this article elaborates on targeting the TME as a strategy to treat acquired drug resistance, reduce tumor metastasis, recurrence, and improve efficacy.

ARHGAP11A Promotes the Malignant Progression of Gastric Cancer by Regulating the Stability of Actin Filaments through TPM1.

The mechanism underlying the poor prognosis of gastric cancer, including its high degree of malignancy, invasion, and metastasis, is extremely complicated. Rho GTPases are involved in the occurrence and development of a variety of malignant tumors. ARHGAP11A, in the Rho GTPase activating protein family, is highly expressed in gastric cancer, but its function and mechanism have not yet been explored. In this study, the effect of ARHGAP11A on the occurrence and development of gastric cancer and the mechanism related to this effect were studied. The expression of ARHGAP11A was increased in gastric cancer cells and tissues, and high ARHGAP11A expression in tissues was related to the degree of tumor differentiation and poor prognosis. Moreover, ARHGAP11A knockout significantly inhibited cell proliferation, cell migration, and invasion in vitro and significantly inhibited the tumorigenic ability of gastric cancer cells in nude mice in vivo. Further studies revealed that ARHGAP11A promotes the malignant progression of gastric cancer cells by interacting with TPM1 to affect cell migration and invasion and the stability of actin filaments. These results suggest that ARHGAP11A plays an important role in gastric cancer and may become a useful prognostic biomarker and therapeutic target for gastric cancer patients.

A Mycochemical Investigation of the Black Lingzhi Mushroom, Amauroderma rugosum (Agaricomycetes), Reveals Several Lipidic Compounds with Anti-Inflammatory and Antiproliferative Activities.

A mycochemical investigation on the medicinal mushroom Amauroderma rugosum led to the isolation of 30 compounds, including 14 sterols, 6 phenolic constituents, 5 unsaturated fatty acids, and 5 other compounds. The structures of these compounds were elucidated by comparison of their nuclear magnetic resonance spectroscopic and mass spectrometry data with literature data. Among them, compound 27 was obtained as a new natural compound, and compounds 2-4, 7-13, and 15-30 were isolated from the genus Amauroderma for the first time. Sterols and unsaturated fatty acids showed anti-inflammatory and antiproliferative activities in vitro. Compounds 5 and 6 showed the highest inhibitory effect on nitric oxide production in lipopolysaccharide-induced murine macrophage RAW264.7 cells, with half maximal inhibitory concentration (IC50) values of 27.6 ± 2.1 µM and 15.3 ± 2.0 µM respectively. Compound 17 exhibited the strongest inhibition against HepG2 and MDA-MB-231 cell lines, with IC50 values < 25 µM. This study not only enriches the understanding of the diversity of chemical constituents in A. rugosum, but it also provides a basis for further development and utilization of A. rugosum as a source of new potential antitumor or anti-inflammatory chemotherapy agents.

Systematic analysis reveals a lncRNA-miRNA-mRNA network associated with dasatinib resistance in chronic myeloid leukemia.

BACKGROUND: Chronic myelogenous leukemia (CML) is a malignant tumor formed by the clonal proliferation of bone marrow hematopoietic stem cells. CML is a relatively rare disease, mainly affecting elderly patients, but the prevalence of CML is expected to increase dramatically. The tyrosine kinase inhibitors (TKIs) have changed the CML patients' treatment patterns and improved its treatment effect, but drug resistance still remains a significant problem to be solved. Therefore, the identification of biomarkers of CML resistance involved therein is essential for treatment and prognosis prediction. METHODS: Bioinformatics was used to analyze and construct a lncRNA-miRNA-mRNA network of CML resistance to dasatinib and predict key lncRNAs. RESULTS: By screening differentially expressed genes in CML resistant to dasatinib and comprehensively analyzing their functions and signal pathways, the core genes in these differential genes were found, and by predictive analysis of the upstream targets of these core genes. Finally, a network diagram containing lncRNA, miRNA, and mRNA was constructed. CONCLUSIONS: MALAT1 as a lncRNA may be a tumor suppressor in patients with CML. According to our data, MALAT1 may have potential role as a molecular biomarker for the occurrence and development of CML resistance to dasatinib.

The upper eyelid levator weakening procedure for the correction of severe cicatricial entropion caused by trachoma.

BACKGROUND: Trachoma-induced upper eyelid cicatricial entropion (UCE) is a common and challenging eyelid disease. Surgeons have developed various surgical techniques to address UCE in the world. However, there are few reports about surgery for Chinese patients. Our study aims to evaluate the esthetic and functional outcomes of correction of trachoma-induced UCE using upper eyelid levator weakening combined with tarsotomy and an anterior lamella recession procedure in China. METHODS: A retrospective non-comparative study was performed in the Ophthalmology Department of Second Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2017 to December 2019. Thirty-six patients (56 eyelids) with severe UCE caused by trachoma, defined as shortening and retraction of the posterior lamella, were collected. Upper eyelid levator weakening combined with tarsotomy and an anterior lamella recession procedure was done on all patients. The mean follow-up time was 11.6±2.71 months (range, 6-24 months). RESULTS: Among the patients, 48 eyelids (85.7%) achieved complete success. Recurrence was observed in 4 eyelids (7.1%). No other severe complications occurred. CONCLUSIONS: This case series showed that upper eyelid levator weakening combined with tarsotomy and an anterior lamella recession procedure is a safe and effective treatment for severe trachoma-induced UCE in Chinese patients.

Nebivolol combined with tetrahydrobiopterin affects diastolic function in spontaneously hypertensive rats via the nitric oxide/cyclic guanosine monophosphate signalling pathway.

BACKGROUND: Hypertension is the the primary cause of diastolic heart failure. Oxidative stress plays an important role in cardiac diastolic dysfunction caused by hypertension. The occurrence of oxidative stress is related to the level of nitric oxide (NO) in the body. Tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. Nebivolol can reduce myocardial oxidative stress and increase NO activity. Therefore, we investigated the effects of monotherapy or combination therapy of different doses of BH4 and nebivolol on cardiac diastolic function in spontaneously hypertensive rats, and preliminarily expounded the related mechanisms. METHODS: Left ventricular function was evaluated by non-invasive echocardiographic assessment and invasive right carotid artery catheterization methods. ELISA was used to measure myocardial 3-nitrotyrosine content, NO production, and cyclic guanosine monophosphate (cGMP) concentration in the myocardium; quantitative real-time PCR (qRT-PCR) was used to determine endothelial nitric oxide synthase (eNOS), phospholamban and sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) mRNA expression levels; Western blot was used to detect the protein expression levels of eNOS and eNOS dimers in myocardial tissue, and immunohistochemical detection of cGMP expression in the myocardium was performed. RESULTS: Studies have shown that compared with those in the control group, NO generation and the expression level of myocardial eNOS mRNA, eNOS expression of dimers, phospholamban, SERCA2a and cGMP increased significantly after the combined intervention of BH4 and nebivolol, while the expression of 3-nitrotyrosine was significantly decreased. CONCLUSIONS: The combined treatment group had a synergistic effect on reducing myocardial oxidative stress, increasing eNOS content, and increasing NO production, and had a more obvious protective effect on diastolic dysfunction through the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway.

Rho GTPases and related signaling complexes in cell migration and invasion.

Cell migration and invasion play an important role in the development of cancer. Cell migration is associated with several specific actin filament-based structures, including lamellipodia, filopodia, invadopodia and blebs, and with cell-cell adhesion, cell-extracellular matrix adhesion. Migration occurs via different modes, human epithelial cancer cells mainly migrate collectively, while in vivo imaging studies in laboratory animals have found that most cells migrate as single cells. Rho GTPases play an important role in the process of cell migration, and several Rho GTPase-related signaling complexes are also involved. However, the exact mechanism by which these signaling complexes act remains unclear. This paper reviews how Rho GTPases and related signaling complexes interact with other proteins, how their expression is regulated, how tumor microenvironment-related factors play a role in invasion and metastasis, and the mechanism of these complex signaling networks in cell migration and invasion.

The prognosis analysis of RFWD2 inhibiting the expression of ETV1 in colorectal cancer.

BACKGROUND: The poor prognosis is partly due to the lack of efficient methods for early diagnosis on colorectal cancer (CRC). METHODS: Bioinformatic analysis and Immunohistochemical analysis were used to evaluate E3 ubiquitin ligase Ring finger and WD domain 2 (RFWD2) and ETS variant 1 (ETV1) mRNA and protein expression levels. RESULTS: The abundance of RFWD2 and ETV1 proteins from 76 CRC patients were examined. The relationship between their expression levels and clinic pathological parameters including prognostic significances were also detected. The expression of RFWD2 and ETV1 and the relative genes functions in CRC through bioinformatics methods were further analyzed. CONCLUSIONS: In conclusion, RFWD2 functioning as a tumor suppressor by negative regulating ETV1, which might play an important role in the development and progression of CRC. RFWD2 and ETV1 have the potential to serve as a pair of molecular biomarkers for the early diagnosis of CRC.

Erratum to the prognosis analysis of RFWD2 inhibiting the expression of ETV1 in colorectal cancer.

[This corrects the article DOI: 10.21037/tcr.2019.11.35.].

Development and validation of a CT-based radiomic nomogram for preoperative prediction of early recurrence in advanced gastric cancer.

BACKGROUND: In the clinical management of advanced gastric cancer (AGC), preoperative identification of early recurrence after curative resection is essential. Thus, we aimed to create a CT-based radiomic model to predict early recurrence in AGC patients preoperatively. MATERIALS AND METHODS: We enrolled 669 consecutive patients (302 in the training set, 219 in the internal test set and 148 in the external test set) with clinicopathologically confirmed AGC from two centers. Radiomic features were extracted from preoperative diagnostic CT images. Machine learning methods were applied to shrink feature size and build a predictive radiomic signature. We incorporated the radiomic signature and clinical risk factors into a nomogram using multivariable logistic regression analysis. The area under the curve (AUC) of operating characteristics (ROC), accuracy, and calibration curves were assessed to evaluate the nomogram's performance in discriminating early recurrence. RESULTS: A radiomic signature, including three hand crafted features and six deep learning features, was significantly associated with early recurrence (p-value <0.0001 for all sets). In addition, clinical N stage, carbohydrate antigen 199 levels, carcinoembryonic antigen levels, and Borrmann type were considered useful predictors for early recurrence. The nomogram, combining all these predictors, showed powerful prognostic ability in the training set and two test sets with AUCs of 0.831 (95% CI, 0.786-0.876), 0.826 (0.772-0.880) and 0.806 (0.732-0.881), respectively. The predicted risk yielded good agreement with the observed recurrence probability. CONCLUSIONS: By incorporating a radiomic signature and clinical risk factors, we created a radiomic nomogram to predict early recurrence in patients with AGC, preoperatively, which may serve as a potential tool to guide personalized treatment.

CPSF3 is a promising prognostic biomarker and predicts recurrence of non-small cell lung cancer.

Cleavage polyadenylation specificity factor (CPSF) is the core component of the 3'-end processing complex, which determines the site of 3'-end cleavage interactions of specific sequence elements within pre-mRNAs. The present study revealed that all members of the CPSF complex were overexpressed in lung cancer tissue from The Cancer Genome Atlas (TCGA) Lung Cancer Cohort compared with normal lung tissue. Analysis of overall survival and recurrence-free survival verified that only CPSF3 was associated with prognosis and recurrence of lung adenocarcinoma (LUAD), and thus could be a promising biomarker. Additionally, receiver operating characteristic curve analysis revealed that CPSF3 may function as a diagnostic biomarker to distinguish between two histological subtypes of non-small cell lung cancer. Furthermore, analysis of the association of CPSF3 expression with clinicopathological parameters indicated that CPSF3 was associated with smoking history, tumor diameter, lymph node metastasis, clinical stage and radiation therapy in LUAD. Additionally, analysis of the DNA methylation data of the TCGA-LUAD Cohort revealed that CPSF3 DNA CpG sites (cg12057242 and cg25739938) were generally hypomethylated in LUAD compared with normal lung tissue. Correlation analysis identified the CPSF3 DNA CpG site cg25739938 to be negatively correlated with CPSF3 expression, while no correlation was identified with cg12057242. In addition, correlation analysis demonstrated that the overexpression of CPSF3 was correlated with CPSF3 DNA copy number variants (CNAs). The findings indicate that abnormal expression of CPSF3 may be caused by DNA CNAs; and DNA hypermethylation and function may be a promising diagnostic and prognostic indicator for LUAD.

MRI reporter gene MagA suppresses transferrin receptor and maps Fe2+ dependent lung cancer.

As a magnetic resonance imaging (MRI) reporter gene, MagA has become a powerful tool to monitor dynamic gene expression and allowed concomitant high resolution anatomical and functional imaging of subcellular genetic information. Here we establish a stably expressed MagA method for lung cancer MRI. The results show that MagA can not only enhance both in vitro and in vivo MRI contrast by specifically alternating the transverse relaxation rate of water, but also inhibit the malignant growth of lung tumor. In addition, MagA can regulate magnetic nanoparticle production in grafted tissues and also suppress transferrin receptor expression by acting as an iron transporter, and meanwhile can permit iron biomineralization in the presence of mammalian iron homeostasis. This work provides experimental evidence for the safe preclinical applications of MagA as both a potential inhibitor and an MRI-based tracing tool for iron ion-dependent lung cancer.