The m6A methyltransferase METTL3 drives thyroid cancer progression and lymph node metastasis by targeting LINC00894.

BACKGROUND: Long noncoding RNAs (lncRNAs) are significant contributors to various human malignancies. The aberrant expression of lncRNA LINC00894 has been reported in various human malignancies. We aimed to illustrate the role of LINC00894 and its underlying mechanism in the development of papillary thyroid carcinoma (PTC). METHODS: We performed bioinformatics analysis of differentially expressed RNAs from TCGA and GEO datasets and selected the target lncRNA LINC00894. SRAMP analysis revealed abundant M6A modification sites in LINC00894. Further analysis of StarBase, GEPIA, and TCGA datasets was performed to identify the related differentially expressed genes METTL3. Colony formation and CCK-8 assays confirmed the relationship between LINC00894, METTL3, and the proliferative capacity of PTC cells. The analysis of AnnoLnc2, Starbase datasets, and meRIP-PCR and qRT‒PCR experiments confirmed the influence of METTL3-mediated m6A modification on LINC00894. The study employed KEGG enrichment analysis as well as Western blotting to investigate the impact of LINC00894 on the expression of proteins related to the Hippo signalling pathway. RESULTS: LINC00894 downregulation was detected in PTC tissues and cells and was even further downregulated in PTC with lymphatic metastasis. LINC00894 inhibits the lymphangiogenesis of vascular endothelial cells and the proliferation of cancer cells. METTL3 enhances PTC progression by upregulating LINC00894 by enhancing LINC00894 mRNA stability through the m6A-YTHDC2-dependent pathway. LINC00894 may inhibit PTC malignant phenotypes through the Hippo signalling pathway. CONCLUSION: The METTL3-YTHDC2 axis stabilizes LINC00894 mRNA in an m6A-dependent manner and subsequently inhibits tumour malignancy through the Hippo signalling pathway.

Discussion on the Transoral Vestibular Approach Endoscopy for TC Patients and the Significance of Serum 25-Hydroxyvitamin D Classification.

In order to discuss the transoral vestibular approach endoscopy through oral vestibular approach in TC and the efficacy of 25(OH)D classification, a total of 110 TC patients from January 2020 to June 2021 are selected. The endoscopic group and the control group are respectively established according to different surgical approaches, with 55 cases in each group. The control group received conventional TC resection, while the endoscopic group received endoscopic assisted TC resection through oral vestibular approach. The differences of intraoperative and postoperative indicators, clinical efficacy, incidence of adverse complications, VAS score, and total satisfaction are observed. TC resection assisted by endoscopy through oral vestibular approach can effectively improve all intraoperative indicators and reduce postoperative pain and has high safety in clinical application. In addition, this study conducted in-depth analysis and classification of serum 25(OH)D index level in postoperative TC patients, indicating that the serum 25(OH)D index level is closely related to prognosis, providing a basis for follow-up clinical monitoring of TC patients' signs and optimization of diagnosis and treatment plans.

Circular RNA DGKB Promotes the Progression of Neuroblastoma by Targeting miR-873/GLI1 Axis.

Accumulated evidences suggested that circular RNAs (circRNA) played critical roles in tumorigenesis and progression. To our knowledge, no study reported the function of circular RNA DGKB (circDGKB, circRNA ID: hsa_circ_0133622) on progression of neuroblastoma (NB). Here, we showed that circDGKB was upregulated in NB tissues compared to the normal dorsal root ganglia. Moreover, the expression level of circDGKB was negatively correlated with the survival rate of NB patients. Mechanically, overexpression of circDGKB promoted the proliferation, migration, invasion, and tumorigenesis of NB cells and reduced cell apoptosis, and vice versa. In addition, qRT-PCR and/or Western blot results showed that circDGKB overexpression inhibited the expression level of miR-873 and enhanced GLI1 expression. Moreover, miR-873 functioned an opposite role to circDGKB and significantly weakened circDGKB role in promoting NB progression. Furthermore, GLI1 upregulation also rescued the miR-873 role in inhibiting NB progression. In conclusion, our work proved that circDGKB promoted NB progression via targeting miR-873/GLI1 axis in vitro and in vivo. Our study provided a new target for NB treatment and indicated that circDGKB could act as a novel diagnostic marker for NB.

Rapid determination of aflatoxin B1 by an automated immunomagnetic bead purification sample pretreatment method combined with high-performance liquid chromatography.

We aimed to establish an automated versatile sample preconcentration method based on the modified immunomagnetic beads, which was utilized to enrich for aflatoxin B1 from the matrices. The critical main parameters affecting the extraction efficiency, such as usage amount of immunomagnetic beads, reaction time, elution time, and blending way were investigated. Under the optimized conditions, the content of aflatoxin B1 was analyzed by high-performance liquid chromatography, the mobile phase consists of water-acetonitrile-methanol (42:18:10, v/v/v), and fluorescence detection was performed with excitation and emission wavelengths at 360 and 440 nm, respectively. Moreover, the performance of preconcentration method was compared with the conventional method based on the immunoaffinity column. The accuracy of two clean-up methods was within the error range. In addition, the stability and recyclability of the immunomagnetic beads was studied by recycling them five times. The results for the respective analysis in various samples demonstrated that the developed extraction platform provides a promising approach that is simple, rapid, sensitive, and easy to use.

Long non­coding RNA H19 protects H9c2 cells against hypoxia­induced injury by activating the PI3K/AKT and ERK/p38 pathways.

Myocardial ischemia/reperfusion injury often leads to adverse cardiovascular outcomes due to severe hypoxia. The present study aimed to evaluate the effects and mechanism of long non­coding RNA H19 (H19) on rat H9c2 cells with hypoxia­induced injury. H9c2 cells were infected with lentiviruses to express H19 or H19­targeting short hairpin RNA (shRNA), or their respective controls, at a multiplicity of infection of 1:100. H19 expression was determined by reverse transcription­quantitative PCR. Hypoxic injury was induced and assessed by analyzing the level of apoptosis, the cell cycle distribution and the mitochondrial membrane potential using flow cytometry in the different groups. The expression of the PI3K/AKT and the ERK/p38 signaling pathways were analyzed using western blotting. It was found that hypoxia stimulated apoptosis, induced G1 phase cell cycle arrest and increased the mitochondrial depolarization rate in H9c2 cells. When compared with the hypoxic model group, the H19 overexpression group had a significantly reduced rate of apoptosis (P=0.016), a smaller G1 population and a higher S phase population (P=0.018 and P=0.031, respectively), and a reduced mitochondrial depolarization rate (P=0.036). By contrast, the H19 shRNA group exhibited the opposite trends, suggesting that hypoxia­induced injury was alleviated by the overexpression of H19 and was aggravated by the knockdown of H19. The present mechanistic studies revealed that H19 may decrease hypoxia­induced cell injury by activating the PI3K/AKT and ERK/p38 pathways. The results of the present study suggested that H19 may alleviate hypoxia­induced myocardial cell injury through the activation of the PI3K/AKT and ERK/p38 pathways.

TRIP13 interference inhibits the proliferation and metastasis of thyroid cancer cells through regulating TTC5/p53 pathway and epithelial-mesenchymal transition related genes expression.

This study aimed to investigate the effect of interfering thyroid hormone receptor interacting protein 13 (TRIP13) expression on the proliferation, apoptosis and metastasis of thyroid cancer (TC) cells and the involved mechanisms. RT-PCR, immunohistochemical analysis and western blot found that compared with normal tissues, the expressions of TRIP13 and N-cadherin in TC tissues were significantly increased, while the expressions of tetratricopeptide repeat protein 5 (TTC5), p-p53 and E-cadherin were significantly decreased (P < 0.05). RT-PCR and western blot revealed that compared with C643 cells, TRIP13 expression in TPC1 cells and BHT101 cells increased significantly (P < 0.05). Therefore, TPC1 cells and BHT101 cells were selected for subsequent experiments. Interference efficiency of TRIP13 interference sequences (sh-TRIP13) was verified by RT-PCR and western blot. After sh-TRIP13 transfection, cell viability and migration rates of cells at 24 h and 48 h decreased significantly (P < 0.05); the number of S phase cells increased remarkably, while the number of G1 and G2 phase cells decreased significantly (P < 0.05); cell apoptosis was enhanced sharply (P < 0.05); cell numbers in the lower chamber of Transwell assay were reduced significantly (P < 0.05). RT-PCR and western blot found that compared with the Control group, expressions of TTC5 and E-cadherin in sh-TRIP13 group were elevated sharply, while N-cadherin expression decreased significantly (P < 0.05). Compared with the Control group, sh-TRIP13 transfection elevated the ratio of p-p53 expression to p53 expression (p-p53/p53) remarkably (P < 0.05). In conclusion, TRIP13 interference inhibited the proliferation and metastasis of thyroid cancer cells through regulating TTC5/p53 pathway and epithelial-mesenchymal transition related genes expression.

Identification of Altered Circular RNA Expression in Serum Exosomes from Patients with Papillary Thyroid Carcinoma by High-Throughput Sequencing.

BACKGROUND This study aimed to identify altered exosome circular RNA (circRNA) in the serum of patients with papillary thyroid carcinoma using high-throughput sequencing. MATERIAL AND METHODS Serum was collected from three patients with papillary thyroid carcinoma and three patients with a benign thyroid goiter. Exosomes were isolated using an exosome isolation kit and confirmed by transmission electron microscopy. Exosome circRNAs were analyzed by high-throughput sequencing using the HiSeq 4000 sequencer. The differentially expressed circRNAs were confirmed by fluorescence quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS Twenty-two differentially expressed circRNAs were screened, which included three that were upregulated and 19 that were down-regulated in serum from patients with papillary thyroid carcinoma compared with controls. Gene Ontology (GO) enrichment analysis showed that these differentially expressed circRNAs were associated with 16 signaling pathways, including the thyroid hormone signaling pathway, the PI3K-Akt signaling pathway, and the AMPK signaling pathway. Three differentially regulated circRNAs included hsacirc_007293, hsacirc_031752, and hsacirc_020135 were confirmed by qRT- PCR. The expression trends were consistent between the high-throughput sequencing technique and qRT-PCR. CONCLUSIONS The findings from this study have shown that gene regulation can be studied from exosomes obtained from serum samples in patients with papillary thyroid carcinoma, and supports the need for further studies on the role of exosome circRNAs in thyroid cancer.