Enhanced treatment of cerebral ischemia-Reperfusion injury by intelligent nanocarriers through the regulation of neurovascular units.

Reperfusion injury is one of the major causes of disability and death caused by ischemic stroke, and drug development focuses mainly on single neuron protection. However, different kinds of cells in the neurovascular units (NVUs), including neurons, microglia and vascular endothelial cells, are pathologically changed after cerebral ischemia-reperfusion injury, resulting in an urgent need to develop a drug delivery system to comprehensively protect the kinds of cells involved in the NVU. Herein, we have constructed a c(RGDyK) peptide modified, NF-κB inhibitor caffeic acid phenethyl ester (CAPE)-loaded and reactive nitrogen species (RNS) stimuli-responsive liposomal nanocarrier (R-Lipo-CAPE) to target ischemic lesions and then remodel the NVU to reduce the progression of cerebral ischemia-reperfusion injury. The R-Lipo-CAPE liposomes were approximately 170 nm with a zeta potential of -30.8 ± 0.2 mV. The in vitro CAPE release behavior from R-Lipo-CAPE showed an RNS-dependent pattern. For in vivo studies, transient middle cerebral artery occlusion/reperfusion (MCAO) model mice treated with R-Lipo-CAPE had the least neurological impairment and decreased brain tissue damage, with an infarct area of 13%, compared with those treated with saline of 53% or free CAPE of 38%. Furthermore, microglia in the ischemic brain were polarized to the tissue-repairing M2 phenotype after R-Lipo-CAPE treatment. In addition, R-Lipo-CAPE-treated mice displayed a prominent down-regulated expression of MMP-9 and restored expression of the tight junction protein claudin-5. This proof-of-concept indicates that R-Lipo-CAPE is a promising nanomedicine for the treatment of cerebral ischemia-reperfusion injury through the regulation of neurovascular units. STATEMENT OF SIGNIFICANCE: Based on the complex mechanism and difficulty in treatment of cerebral ischemia-reperfusion injury, the overall regulation of neurovascular unit has become an extremely important target. However, little nanomedicine has been directed to remodel the neurovascular units in targeted cerebral ischemia-reperfusion injury therapy. Here, c(RGDyK) peptide modified reactive nitrogen species (RNS) stimuli-responsive liposomal nanocarrier loaded with a NF-κB inhibitor (CAPE), was designed to simultaneously regulate various cells in the microenvironment of cerebral ischemia-reperfusion injury to remodel the neurovascular units. Our in vitro and in vivo data showed that the intelligent nanocarrier exerted the ability of pathological signal stimuli-responsive drug release, cerebral ischemia-reperfusion injury site targeting and neurovascular units remodeling through reducing neuron apoptosis, regulating microglia polarization and repairing vascular endothelial cell. Overall, the intelligent liposomal drug delivery system was a promising and safe nanomedicine in the perspective of cerebral ischemia-reperfusion injury treatment.

circ-PSD3 promoted proliferation and invasion of papillary thyroid cancer cells via regulating the miR-7-5p/METTL7B axis.

Papillary thyroid cancer (PTC) is a common tumor malignancy of the endocrine system worldwide. Recently, circular RNAs (circRNAs) have been reported to participate in diverse pathological processes, especially in tumorigenesis. However, the functional role and mechanism of circRNA pleckstrin and Sec7 domain containing 3 (circ-PSD3) in PTC are still unclear. In this study, qRT-PCR results showed that circ-PSD3 was significantly upregulated in PTC tissues and cell lines. Meanwhile, circ-PSD3 overexpression was positively associated with larger tumor size, TNM stage, and lymph node metastasis. Knockdown of circ-PSD3 suppressed the proliferation and invasion of PTC cells. Besides, circ-PSD3 interacted with miR-7-5p to reduce its expression, and methyltransferase like 7B (METTL7B) was verified as a target gene of miR-7-5p. Functionally, inhibition of circ-PSD3 impeded PTC cell proliferation and invasion via targeting miR-7-5p to downregulate METTL7B expression. Taken together, silencing of circ-PSD3 hampered the proliferation and invasion of PTC cells via upregulating the inhibitory effect of miR-7-5p on METTL7B expression. Therefore, circ-PSD3 could be a potential diagnostic biomarker or molecular treatment target for PTC.

M2-like tumor-associated macrophages-secreted Wnt1 and Wnt3a promotes dedifferentiation and metastasis via activating ß-catenin pathway in thyroid cancer.

BACKGROUND: Thyroid carcinoma (TC) has been a global issue for its rapid increasing incidence worldwide. Although most TC was not so aggressive with a good prognosis, treatment against anaplastic TC was relatively limited and the mechanisms are not well elucidated yet. METHODS: TC cell lines (IHH4 and TPC-1) were used. Flow cytometry was used to identify the surface marker of M2-like tumor-associated macrophages (TAMs) from cell culture. Quantitative real-time polymerase chain reaction, western blot analysis, immunostaining, and immunohistochemistry were used to detect the expression of Wnt1, Wnt3a, components of Wnt/ß-catenin pathway, and proliferation/epithelial-mesenchymal transition (EMT)-related proteins. Alkaline phosphatase activity assay, colony formation assay, and transwell assay were used to examine the roles of Wnt1, Wnt3a, and ß-catenin pathway in cell dedifferentiation, proliferation, migration, and invasion of TC cells, respectively. Subcutaneous tumor growth was monitored in nude mice. RESULTS: Coculture with M2-like TAMs facilitated dedifferentiation, proliferation, migration, and invasion in TC cells. EMT and proliferation-related proteins were also promoted in cocultured TC cells. The level of Wnt1 and Wnt3a was increased in the coculture system. Block of Wnt1 or Wnt3a suppressed malignant behaviors in cocultured tumor cells. Furthermore, Wnt1 or Wnt3a knockdown inhibited Wnt/ß-catenin signaling pathway, and suppressed EMT and proliferation-related signals in cocultured tumor cells. Knockdown of Wnt1 or Wnt3a inhibited tumor growth in xenograft model. CONCLUSION: M2-like TAMs promoted dedifferentiation, proliferation, and metastasis of TC by Wnt1 and Wnt3a secretion and ensuing ß-catenin activation.

Differential expression of a set of microRNA genes reveals the potential mechanism of papillary thyroid carcinoma.

BACKGROUND: Our aim was to explore the potential mechanism underlying papillary thyroid carcinoma (PTC) development. METHODS: Gene expression profile data GSE3467 and microRNA (miRNA) expression profile data E-TABM-68 were downloaded from Gene Expression Omnibus and Array Express database respectively. The differentially expressed genes (DEGs) and miRNAs between PTC patients and normal individuals were screened. Then, the significant target DEGs regulated by differentially expressed miRNAs were mapped to protein-protein interaction (PPI) network and functional modules were screened. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis for miRNA genes were performed using DAVID (the Database for Annotation, Visualization and Integration Discovery) tool. RESULTS: Total 4307 DEGs and 23 differentially expressed miRNAs were identified. A PPI subnetwork containing 612 nodes and 713 edges was constructed. Total 5 DEGs such as SPARC (secreted protein acidic and rich in cysteine), FN1 (fibronectin 1), THBS1 (thrombospondin 1), COL1A1 (collagen, type I, alpha 1) and COL7A1 (collagen, type VII, alpha 1) were found in module M1. The up-regulated DEGs were significantly related with cell adhesion molecules (CAMs), response to wounding and immune response. The down-regulated DEGs were significantly enriched in metabolism related pathways and transcription related with GO terms. CONCLUSIONS: ECM-receptor interaction and amino acid degradation may play key roles in the mechanism of PTC progression.

lncRNA DGCR5 acts as a tumor suppressor in papillary thyroid carcinoma via sequestering miR-2861.

A vast amount of evidence indicates that long non-coding RNAs (lncRNAs) are involved in cancer. Previous studies have indicated that lncRNA DiGeorge syndrome critical region gene 5 (DGCR5) is aberrantly expressed in lung cancer, pancreatic ductal adenocarcinoma and hepatocellular carcinoma. However, the role of DGCR5 in papillary thyroid carcinoma (PTC) has remained elusive. In the present study, it was revealed that DGCR5 was significantly downregulated in PTC tissues compared with that in adjacent normal tissues. Through functional experiments, it was demonstrated that ectopic overexpression of DGCR5 markedly suppressed PTC cell growth and invasion. A bioinformatics analysis suggested that DGCR5 binds to microRNA (miR)-2861. A total of 5 putative binding sites for miR-2861 were identified in DGCR5, and a luciferase reporter assay confirmed the direct interaction between DGCR5 and miR-2861. Furthermore, reverse transcription-quantitative polymerase chain reaction analysis indicated that ectopic overexpression of DGCR5 led to a decreased expression of miR-2861 in PTC cells and miR-2861 mimic transfection caused a downregulation of DGCR5. miR-2861 level was upregulated in PTC tissues compared with adjacent tissues and negatively correlated with DGCR5 level. In addition, rescue experiments indicated that ectopic expression of miR-2861 reversed the effects of DGCR5 overexpression on PTC cell proliferation and invasion. Taken together, the present results demonstrated that DGCR5 inhibits PTC progression via sponging miR-2861, indicating DGCR5 may serve as a therapeutic target.

Downregulation of NEAT1 reverses the radioactive iodine resistance of papillary thyroid carcinoma cell via miR-101-3p/FN1/PI3K-AKT signaling pathway.

Considering the resistance of papillary thyroid cancer (PTC) 131I therapy, this study was designed to find a solution at molecular respect. By probing into lncRNA-NEAT1/miR-101-3p/FN1 axis and PI3K/AKT signaling pathway, this study provided a potential target for PTC therapy. 131I-resistant cell lines were established by continuous treatment with median-lethal 131I. Bioinformatic analysis was applied to filtrate possible lncRNA/miRNA/mRNA and related signaling pathway. Luciferase reporter assay was employed in the verification of the targeting relationship between lncRNA and miRNA as well as miRNA and mRNA. MTT assay and flow cytometry assay were performed to observe the impact of NEAT1/miR-101-3p/FN1 on cell viability and apoptosis in radioactivity iodine (RAI)-resistant PTC cell lines, respectively. Western blot and qRT-PCR were conducted to measure the expression of proteins and mRNAs in RAI-resistant PTC tissues and cells. Meanwhile, endogenous PTC mice model were constructed, in order to verify the relation between NEAT1 and RAI-resistance in vivo. NEAT1 was over-expressed in RAI-resistant PTC tissues and cell lines and could resist RAI by accelerating proliferation accompanied by suppressing apoptosis. It indicated that overexpressed NEAT1 restrained the damage of RAI to tumor in both macroscopic and microcosmic. Besides, NEAT1/miR-101-3p exhibited a negative correlation by directly targeting each other. The expression of FN1, an overexpressed downstream protein in RAI-resistance PTC tissues, could be tuned down by miR-101-3p, while the decrease could be restored by NEAT1. In conclusion, both in vitro and in vivo, NEAT1 suppression could inhibit 131I resistance of PTC by upregulating miR-101-3p/FN1 expression and inactivated PI3K/AKT signaling pathway both in vitro and in vivo.

Correlation between KRAS genemutationandDTC resistance to 131I radiotherapy and prognosis / 中国肿瘤生物治疗杂志

@# Objective: To investigate the correlation between KRAS gene mutation and differentiated thyroid carcinoma (DTC) treatment effect and prognosis, and to explore the mechanism. Methods: Clinical tissue samples from DTC patients undergoing 131I Radiotherapy were collected. Then single strand conformation polymorphism analysis of polymerase chain reaction products (PCRC-SSCP) was used to detect KRAS mutation rate in thyroid cancer patients of different TNM stages; p21 protein expression level was detected by real-time quantitative polymerase chain reaction (qPCR) and western blotting. DTC cells were treated by sub-lethal dose of 131I Radiotherapy, and then CCK-8 assay, transwell assay and flow cytometry (FCM) were used to evaluate the changes of cells viability. Animal models were then constructed for verification. Results: The results showed that KRAS gene mutants were increased in 131I-resistant DTC patients; KRAS gene mutation suppressed p21 protein expression and was associated with clinical stage and poor prognosis. In vivo and in vitro experiments proved that sub-lethal dose of 131I increased KRAS gene mutation rate, suppressed p21 expression level, and caused 131I radiotherapy resistance. Reversely, over-expression of KRAS gene could significantly increase p21 expression, and inhibit tumor proliferation and metastasis. Conclusion: KRAS gene mutations were associated with DTC TNM stages and 131I resistance in DTC patients. Sub-lethal dose of 131I treatment could improve 131I resistance in DTC cells line, inversely, over-expressed KRAS gene could increase the sensitivity to 131I radiotherapy in DTC patients.

Emerging roles of circRNA_NEK6 targeting miR-370-3p in the proliferation and invasion of thyroid cancer via Wnt signaling pathway.

OBJECTIVE: To identify the significantly altered circRNAs and mRNAs in thyroid cancer, investigate their target miRNAs and determine their biological functions. METHODS: The differentially expressed circRNAs, mRNAs and pathways in thyroid cancer were identified by microarray analysis and gene set enrichment analysis (GSEA). The correlative circRNAs and mRNAs were found out through Pearson correlative analysis. The common target miRNAs of circNEK6 and FZD8 related to thyroid cancer was screened out through Targetscan, miRanda and HMDD analysis. The mRNA and protein expressions in thyroid cancer tissues and cells were detected by qRT-PCR and western blot. CircRNA was confirmed by the RNase R digestion and nucleic acid electrophoresis. The target relationships were verified by the dual luciferase reporter assay. Cell viability, invasion and apoptosis were determined by MTT assay, Transwell assay and flow cytometry, respectively. RESULTS: CircNEK6 and FZD8 were significantly up-regulated in thyroid cancer, with strong correlations. The Wnt signaling pathway was activated in thyroid cancer. MiR-370-3p was the common target miRNA of circNEK6 and FZD8, and it was down-regulated in thyroid cancer. Overexpression of circNEK6 and FZD8 could promote the growth and invasion of thyroid cancer cells, while up-regulation of miR-370-3p could suppress thyroid cancer progression and inhibit the Wnt signaling pathway. MiR-370-3p's effect on thyroid cancer cells could be rescued by circNEK6 or FZD8. CONCLUSION: CircNEK6 promoted the progression of thyroid cancer through up-regulating FZD8 and activating Wnt signaling pathway by targeting miR-370-3p.

Effects of nuclear factor­κB on the uptake of 131iodine and apoptosis of thyroid carcinoma cells.

Thyroid carcinoma is primarily treated by surgery combined with radioactive 131iodine (131I) treatment; however, certain patients exhibit resistance to 131I treatment. Previous research indicated that nuclear factor­κB (NF­κB) was associated with resistance to 131I in cancer cells. The present study aimed to investigate the effects of NF­κB on 131I uptake and apoptosis in thyroid carcinoma cells. TPC­1 and BCPAP cell lines were employed as research models in the present study, and the expression of NF­κB was inhibited by RNA interference (RNAi). The ability of TPC­1 and BCPAP cells to uptake 131I was measured and the cell viability was detected by an MTT assay. Finally, the expression of the apoptosis­associated proteins X­linked inhibitor of apoptosis (XIAP), cellular inhibitor of apoptosis protein 1 (cIAP1) and caspase­3 in TCP­1 and BCPAP cells was determined by western blotting. Western blotting results demonstrated that the expression levels of NF­κB in TPC­1 and BCPAP cells were successfully downregulated by RNAi (P<0.05), while analysis of 131I uptake revealed no significant alterations in the 131I uptake ability of cells following RNAi (P>0.05). MTT experiments demonstrated that the inhibition of NF­κB expression in combination with radiation (131I treatment) led to a marked reduction in cell viability (P<0.05). Furthermore, western blot analysis revealed that the inhibition of NF­κB expression downregulated the expression levels of XIAP and cIAP1 (P<0.05), while the expression levels of caspase­3 were upregulated, indicating that the observed reduction in cell viability following NF­κB inhibition may be due to an increased level of apoptosis. Although NF­κB inhibition did not affect the 131I uptake of thyroid cancer cells, this inhibition may increase the apoptotic effects of radioactive 131I.